Genotype-Dependent Effect of Exogenous Nitric Oxide on Cd-induced Changes in Antioxidative Metabolism,
Ultrastructure,and Photosynthetic Performance in Barley Seedlings (Hordeum vulgare )
Fei Chen ?Fang Wang ?Hongyan Sun ?Yue Cai ?Weihua Mao ?
Guoping Zhang ?Eva Vincze ?Feibo Wu
Received:19October 2009/Accepted:2March 2010/Published online:16April 2010óSpringer Science+Business Media,LLC 2010
Abstract A greenhouse hydroponic experiment was performed using Cd-sensitive (cv.Dong 17)and Cd-tol-erant (Weisuobuzhi)barley seedlings to evaluate how dif-ferent genotypes responded to cadmium (Cd)toxicity in the presence of sodium nitroprusside (SNP),a nitric oxide (NO)donor.Results showed that 5l M Cd increased the
accumulation of O 2?-,H 2O 2,and malondialdehyde (MDA)but reduced plant height,chlorophyll content,net photo-synthetic rate (P n ),and biomass,with a much more severe response in the Cd-sensitive genotype.Antioxidant enzyme activities increased signi?cantly under Cd stress in the roots of the tolerant genotype,whereas in leaves of the sensitive genotype,superoxide dismutase (SOD)and ascorbate peroxide (APX),especially cytosol ascorbate peroxidase (cAPX),decreased after 5–15days Cd expo-sure.Moreover,Cd induces NO synthesis by stimulating
nitrate reductase and nitric oxide synthetase-like enzymes in roots/leaves.A Cd-induced NO transient increase in roots of the Cd-tolerant genotype might partly contribute to its Cd tolerance.Exogenous NO dramatically alleviated Cd toxicity,markedly diminished Cd-induced reactive oxygen species (ROS)and MDA accumulation,ameliorated Cd-induced damage to leaf/root ultrastructure,and increased chlorophyll content and P n .External NO counteracted the pattern of alterations in certain antioxidant enzymes induced by Cd;for example,it signi?cantly elevated the depressed SOD,APX,and catalase (CAT)activities in the Cd-sensitive genotype after 10-and 15-day treatments.Furthermore,NO signi?cantly increased stromal APX and Mn-SOD activities in both genotypes and upregulated Cd-induced decrease in cAPX activity and gene expression of root/leaf cAPX and leaf CAT1in the Cd-sensitive genotype.These data suggest that under Cd stress,NO,as a potent antioxidant,protects barley seedlings against oxidative damage by directly and indirectly scavenging ROS and helps to maintain stability and integrity of the subcellular structure.
Keywords Barley (Hordeum vulgare L.)áCadmium (Cd)áNitric oxide (NO)á
Nitric oxide synthase (NOS)áROS metabolism áUltrastructure
Introduction
Cadmium (Cd)is a heavy metal widely recognized as a very dangerous environmental pollutant due to its high toxicity to both plants and animals.Although Cd has a wide variety of toxic effects on plants,the photosynthetic apparatus appears to be particularly susceptible to this
Electronic supplementary material The online version of this article (doi:10.1007/s00344-010-9151-2)contains supplementary material,which is available to authorized users.
F.Chen áF.Wang áH.Sun áY.Cai áW.Mao á
G.Zhang áF.Wu (&)
Department of Agronomy,College of Agriculture and Biotechnology,Huajiachi Campus,Zhejiang University,Hangzhou 310029,People’s Republic of China e-mail:wufeibo@https://www.doczj.com/doc/3414795004.html,
E.Vincze
Faculty of Agricultural Sciences,Department of Genetics and Biotechnology,University of Aarhus,Fors?gsvej 1,4200Slagelse,Denmark
Present Address:F.Chen
The Institute of Crops and Nuclear Technology Utilization,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China
J Plant Growth Regul (2010)29:394–408DOI 10.1007/s00344-010-9151-2
heavy-metal pollutant(di Cagno and others2001).How-ever,little information is available on the effects of Cd on chloroplast ultrastructure such as the thylakoid system,and this knowledge is important in understanding the relation-ship between physiological alterations induced by metal stress and photosynthesis.In addition,studies on different plant species have revealed that Cd produces concentra-tion-dependent imbalances in the antioxidant defenses of plants and induces oxidative stress by inducing the gener-ation of reactive oxygen species(ROS)(Sandalio and others2001;Schu¨tzendu¨bel and others2001;Wu and others2003).The excess formation of ROS,such as the superoxide radical(O2?-),hydroxyl radical(?OH),and hydrogen peroxide(H2O2),can oxidize various cellular components(for example,protein,lipids,and nucleic acids)and result in lipid peroxidation,membrane leakage, and enzyme inactivation,which can?nally lead to oxida-tive injury and alteration in cell structure(Romero-Puertas and others2007).Although plants cope with oxidative stress in a complex system,it is well known that the increased ROS levels could be scavenged by antioxidative enzymes such as superoxide dismutase(SOD,EC 1.15.1.1),ascorbate peroxidase(APX,EC1.11.1.7),cata-lase(CAT,EC 1.11.1.6),and peroxidase(POD,EC 1.11.1.7)(Noctor and Foyer1998).However,different effects of Cd toxicity on the activity of antioxidant enzymes scavenging ROS were reported(Sandalio and others2001;Schu¨tzendu¨bel and others2001;Wu and others2003;Romero-Puertas and others2004).Moreover, SOD,a key enzyme in superoxide radicals dismutated to H2O2,had at least three different isoforms:CuZn-SOD, Mn-SOD,and Fe-SOD(del R?′o and others2003);and APX has at least four distinct compartments:chloroplastic stroma(sAPX),thylakoid membrane(tAPX),microbody (mAPX),and cytosol(cAPX)(Song and others2005).It is meaningful to examine individual SOD and APX isoforms because they have different subcellular locations and dif-ferent metabolic roles(Ishikawa and others1998).Yet, little information is available concerning the possible function of different isoforms of these antioxidative enzymes in Cd tolerance,and most of the existing studies did not investigate the alteration in transcription level of antioxidative enzymes in response to Cd stress.Therefore, more research is needed at the subcellular and molecular levels to elucidate genotypic differences in the antioxida-tive enzyme capacity and the relationship between the corresponding gene expression under Cd stress to gain a deeper insight into the mechanisms of Cd tolerance.
Nitric oxide(NO)is a bioactive gaseous free radical?rst described in mammals(Schmidt and Walter1994).Plant scientists started to pay attention to NO in the late1990s. The explosive growth in the area of research related to NO over the past few years has been rapidly extending to almost all aspects of plant physiology.Undoubtedly,it is an era of great enthusiasm for NO as a plant signaling molecule,and today it is known to play a crucial role in regulating many key physiological processes in plants, such as development and senescence and adaptation to biotic and abiotic stresses(Gould and others2003;Besson-Bard and others2008).Gould and others(2003)reported that heat and osmotic and salinity stresses induced a rapid increase in NO production in tobacco cells.Besson-Bard and others(2009)demonstrated that Cd induces NO syn-thesis in Arabidopsis thaliana seedlings.Furthermore, application of exogenous NO in the form of sodium nitroprusside(SNP),as a NO donor,alleviates the toxic effects caused by heat stress in weed calluses by decreasing H2O2and malondialdehyde(MDA)contents and increas-ing the activities of SOD,CAT,APX,and POD(Song and others2006).The positive effect of NO on oxidative stresses was found after plant exposure to salt(Zhao and others2007),heat(Song and others2006),drought(Mata and Lamattina2001),and ion de?ciency(Graziano and others2002).It has been reported that exogenously applied NO can enhance germination or break seed dormancy (Beligni and Lamattina2000),and when no dormancy breakage is required,greater germination rates have been observed by supplementation with an NO donor(Kopyra and Gwo′z′dz′2003).Once NO is endogenously generated or gets inside the cell from an exogenous source,it reacts with a wide range of targets,including protein and nonprotein thiols and the superoxide anion O2-.
Nitrate reductase(NR,EC 1.6.1.6)and NOS-like enzymes are the two main enzymes involved in NO syn-thesis in plant cells.NR can catalyze the reduction of nitrate to nitrite and further reduce nitrite to NO;this was observed in ABA-induced stomatal closure(Garcia-Mata and others2003).In animal cells,NO is catalyzed from L-Arg by the heme-containing enzyme nitric oxide syn-thase(NOS).Recently,there have been more reports pro-viding evidence for L-Arg-dependent NO synthesis by a putative NOS-like enzyme in plants,and NO production was inhibited by mammalian NOS inhibitors(del R?′o and others2003;Guo and others2003).Therefore,the question arises whether NO participates in Cd tolerance and whether NR and NOS may be important in NO synthesis in barley plants.It is also of great interest to know whether external NO could act as a regulator of antioxidant intervention strategy in preventing oxidative stress in response to Cd stress,and to get a better understanding of how plants adjust to an adverse environment.
The present study reports the genotypic differences in Cd-induced changes in antioxidative metabolism,ultra-structure,and photosynthetic performance,and the role of NO in Cd tolerance using two barley genotypes varying in Cd tolerance.We provided evidence that Cd induced a
signi?cant increase in NO synthesis at the early stage of Cd exposure in barley seedlings,but the Cd-tolerant and Cd-sensitive genotypes showed different responses.Our results supported the hypothesis that NO alleviates Cd-induced oxidative damage in plants via stimulating anti-oxidative enzyme activities,and it helps to maintain the stability and integrity of the subcellular structure under Cd stress.
Materials and Methods
Plant Material and Growth Condition
The hydroponic experiment was performed using two barley genotypes differing in Cd tolerance,Weisuobuzhi and Dong17,relatively Cd-tolerant and Cd-sensitive genotypes,respectively(Chen and others2008).Seeds of individual genotypes were surface sterilized in1%H2O2 for30min,rinsed seven times with distilled water,and then germinated in sterilized moist sand in an incubator at 20±1°C.When seedlings reached the two-leaf stage (10days old),uniform healthy plants were selected and transplanted to5-l containers?lled with4.5l basal nutrient solution.The container was covered with a polystyrol plate with seven evenly spaced holes(2plants per hole)and placed in a greenhouse.Seven days after transplanting,Cd (as CdCl2)and SNP were added to the corresponding containers to form three treatments:basal nutrient solution (control),5l M Cd(Cd),and5l M Cd?0.25mM SNP (Cd?NO).The experiment was laid out as a split-plot design,with treatment as the main plot and genotype as the subplot,and there were six replicates for each treatment. The composition of the basic nutrient solution was (mg l-1):(NH4)2SO4,48.2;MgSO4,65.9;K2SO4,15.9; KNO3,18.5;Ca(NO3)2,59.9;KH2PO4,24.8;Fe-citrate,5; MnCl2á4H2O,0.9;ZnSO4á7H2O,0.11;CuSO4á5H2O,0.04; HBO3,2.9;H2MoO4,0.01.The solution pH was adjusted to5.8±0.1with NaOH or HCl,as required.The nutrient solution was continuously aerated with pumps and renewed every5days.
Plant samples to examine enzyme activities,antioxi-dants,and chlorophyll were collected after1,5,10,15,and 25days of treatment.Fresh leaf fragments were used to measure chlorophyll content and NR activity.For the determination of antioxidative enzymes,NOS activities, and NO content,samples were kept at-70°C.Meanwhile, SOD and APX isoenzyme activities and photosynthesis parameters were measured after15days of treatment,and cytochemistry staining of H2O2and O2?-and leaf/root ultrastructure was also performed.The?rst fully expanded leaves were used in determining all indices.Growth Measurement and Metal Analysis
At25days after treatment,plants were harvested and separated into roots and tops(shoots and leaves).The roots were soaked with20mM Na2EDTA for3h to eliminate the ions on the surface and then washed thoroughly with deionized water.Plant height and root length were mea-sured simultaneously,dried at80°C,and weighed.Dried shoots and roots were powdered and weighed,then ashed at 550°C for12h.The ash was digested with5ml of30% HNO3and then diluted using deionized water.The Cd concentration was quanti?ed using?ame atomic absorption spectrometry(Shimadzu AA-6300;Chen and others2007).
Determination of NO Levels and NOS and NR Activity
NO levels were determined according to the method described by Murphy and Noack(1994).Fresh samples were cut into approximately5-mm segments and immedi-ately incubated with100U CAT and100U SOD for5min to remove endogenous ROS before addition of oxyhemo-globin(5mM).After3min of incubation,NO was quan-ti?ed by spectrophotometric measurement of the conversion of oxyhemoglobin to methemoglobin.The total NOS activity in roots and leaves of barley seedlings was determined by the L-citrulline assay method described by Ribeiro and others(1999),and the NR activity was assayed based on the method of Zhang and Qu(2003). Measurement of Chlorophyll Content
and Photosynthesis Parameters
Chlorophyll content was determined according to the method of Beligini and Lamattina(1999).A LI-6400 portable photosynthesis system(LI-COR,Lincoln,NE) was used to measure net photosynthetic rate(P n),stomatal conductance(G s),transpiration rate(T r),and intracellular CO2concentration(C i)of the?rst fully expanded leaves. Examination of Leaf and Root Ultrastructure
Fresh leaves and root tips were sectioned and?xed with 2.5%glutaraldehyde(v/v)in100mM phosphate buffer (PBS,pH7.0)for6–8h.Samples were washed three times with the same PBS and post-?xed in1%osmium tetroxide (OsO4)for1h.After?xing,samples were dehydrated with ethanol series,in?ltrated,and embedded in Spurr’s resin overnight.Then the specimen sections were stained with uranyl acetate and alkaline lead citrate,respectively,and ultrathin sections(80nm)were prepared.Examination of sections was carried out using a transmission electron microscope(JEOL JEM-1230EX,Japan).
Histochemical Staining of H2O2and O2?-and Determination of MDA Content
Cytochemistry staining of H2O2and O2?-was performed as described by Romero-Puertas and others(2004)with minor modi?cations.In the case of H2O2,leaves were vacuum-in?ltrated with10mM potassium phosphate buffer(PBK, pH6.5)containing1%diaminobenzidine(DAB)for5min and then incubated at25°C for12h in the dark.Leaves were illuminated until the appearance of brown spots, characteristic of the reaction of DAB with H2O2.In the case of O2?-,leaves were in?ltrated with0.1%nitroblue tetrazolium(NBT)in50mM PBK(pH6.4)containing 10mM Na-azide and illuminated until the appearance of dark spots.Leaves were all bleached in boiling ethanol to visualize the spots after incubation.The level of lipid peroxidation was measured as the amount of malondial-dehyde(MDA)which was determined by the thiobarbituric acid(TBA)reaction(Wu and others2003).
Assay of Antioxidant Enzymes
Fresh roots and leaves(0.3g)were homogenized in8ml of50mM PBS(pH7.8)using a prechilled mortar and pestle.Then the homogenates were centrifuged at10,000g for15min and the supernatants were used for enzyme activity assaying.APX,CAT,and POD activities were determined according to the method of Song and others (2005).The activities of SOD and its isoenzymes were assayed by the inhibition of the photochemical reduction of NBT,as described by Yu and Rengel(1999).KCN and H2O2were used to identify the different forms of SOD. KCN inhibits Cu/Zn-SOD but does not affect Mn-SOD or Fe-SOD,whereas H2O2inactivates Cu/Zn-SOD and Fe-SOD without affecting Mn-SOD.Activities of APX isoenzymes in the leaf extracts were determined according to the method of Amako and Asada(1994).Fresh leaves (0.5g)were homogenized in10mM PBK(pH7.0)con-taining1mM AsA,20%(w/v)sorbitol,1mM EDTA,and 0.1%(w/v)phenylmethanesulfonyl?uoride(PMSF),and the homogenates were centrifuged at12,000g for10min. The supernatant was used to determine the activities of sAPX and cAPX.Fifty microliters of supernatant was added to2.0ml of50mM PBK(pH7.0)containing10l M H2O2.One,two,three,and?ve minutes after the start of the incubation,the incubated mixture(1.98ml)was sam-pled and mixed with10l l of100mM AsA and then10l l of20mM H2O2.The oxidation of AsA was followed by a decrease in the A290.The membrane fraction was washed and suspended in10mM PBK(pH7.0)containing1mM AsA.The activities of tAPX and mAPX were assayed separately using the same method that was used to measure the activities of sAPX and cAPX.cAPX and mAPX activities were calculated from the inactivation curve of each isoenzyme.
qRT-PCR Analysis
Total RNA was isolated from roots and leaves with the TRIzol reagent following the manufacturer’s recommen-dation(Invitrogen,Carlsbad,CA,USA).One microgram of each total RNA sample was subsequently used for cDNA synthesis using0.5l g of oligo(dT)12–18(Invitrogen)and 200U of Superscript II(Invitrogen)according to the sup-plier’s recommendation.cDNA samples were assayed by quantitative real-time PCR(qRT-PCR)in the iCycler iQTM Real-time PCR Detection System(Bio-Rad,Her-cules,CA,USA)using the SYBRòGreen PCR Master Mix (Applied Biosystems,Foster City,CA,USA).The PCR conditions consisted of denaturation at95°C for3min, followed by40cycles of denaturation at95°C for30s, annealing at58°C for45s,and extension at72°C for45s.
The following primers were used:POD(X58396),for-ward(fw)-50-TGCTTTGGTCTTATCGCT-30and reverse (rv)-50-GTTTGCCTCATTCTCGTT-30;CAT1(U20777), fw-50-TGAAGTGCCTCTTGGAT-30and rv-50-AGACG GTGCCTTTGGGT-30;cAPX(AJ006358),fw-50-AGGG AGGGAGGACAAGC-30and rv-50-ACCAGAGAGGGCA ACAA-30.Barley actin gene was used as control (AY145451):fw-50-ATGTTTTTTTCCAGACG-30and rv-50-ATCAAGCCAACCCAAGT-30.
Statistical Analysis
Data presented are the averages of at least three indepen-dent replicates.Statistical analyses were performed with the Data Processing System(DPS)statistical software package using ANOVA followed by the Duncan’s multiple range test(SSR)to evaluate signi?cant treatment effects at a signi?cance level of P B0.05.
Results
Cd Toxicity Symptoms and Cd Concentration Symptoms of Cd toxicity(5l M Cd-alone treatment)in barley leaves included brown spots and yellow necrotic patches.Cd toxicity markedly hindered shoot and root elongation and biomass accumulation(Supplementary Fig. S1).Furthermore,time of appearance and severity of Cd toxicity symptoms differed signi?cantly between geno-types(P\0.01).The tolerant genotype Weisuobuzhi was less affected in terms of the above-mentioned growth traits and yellow necrotic patches,whereas the sensitive Dong17 was more affected and Cd toxicity symptoms also appeared
rapidly and severely.To investigate the protective role of NO,0.25mM SNP was added to the5l M Cd medium (Cd?NO).After25days of treatment,plant height,root length,and biomass increased signi?cantly in both geno-types compared with Cd-alone treatment(Supplementary Fig.S1),and NO effectively inhibited the appearance of Cd toxicity such as chlorosis or necrosis in the leaves.
To prove that the SNP-released NO,rather than other substances associated with SNP decomposition(such as cyanide and Fe),was responsible for the SNP-induced alleviation effect on Cd toxicity,Cd-treated lea?ets of Dong 17were treated with200l M K4Fe(CN)6and200l M SNP?200l M cPTIO separately.The results indicated that treatment with neither200l M SNP?200l M cPTIO nor K4Fe(CN)6had an ameliorating effect on Cd-induced inhibition of brown precipitate(Supplementary Fig.S2). This evidence proves the hypothesis that SNP-released NO, rather than other substances from SNP decomposition, accounts for the alleviation effect on Cd toxicity.
Shoot and root Cd concentrations of123.5–140.6mg kg-1DW and1116.1–1147.9mg kg-1DW were detected after25days of5l M Cd treatment.The tolerant genotype Weisuobuzhi showed relatively higher Cd concentrations in shoots than the sensitive Dong17, whereas no signi?cant genotype difference was observed in the roots.The addition of NO signi?cantly reduced Cd concentrations in both genotypes compared with Cd-alone treatment,and the sensitive genotype Dong17showed much more reduction than Weisuobuzhi[7.7and11.5% more reduction than Weisuobuzhi in shoots and roots, respectively(Supplementary Table1)].
Chlorophyll Content and Photosynthetic Parameters There was no signi?cant effect on chlorophyll content of the tolerant genotype Weisuobuzhi plants treated with 5l M Cd except on day5when the chlorophyll content was20.2%lower than in the control.However,a sub-stantial degradation of chlorophyll was detected in the sensitive genotype Dong17,with the largest reduction of 58.2%after25days of Cd exposure.When treated with Cd in the presence of SNP,the chlorophyll content was sig-ni?cantly increased in Weisuobuzhi after1–10days and in Dong17after5–10days compared with Cd-alone treat-ment(Fig.1).Thereafter(15–25days),no differences in chlorophyll content were observed in the Cd?SNP treatments.The sensitive Dong17showed much more drastic alteration in chlorophyll content when SNP was added to the Cd treatments.Although the chlorophyll content of the Cd-alone-treated plants remained signi?-cantly below that of control all the way through the experiment,after10days the plants treated with Cd?
NO Fig.1Chlorophyll contents and transmission electron micrograph of
chloroplasts of Weisuobuzhi(upper)and Dong17(below)cultured in
basic nutrition(BNS,A,D),BNS?5l M Cd(B,E),and
BNS?5l M Cd?0.25mM SNP(C,F).Scale bar=2l M.CW
cell wall,GL granum lamellae,Os osmiophilic plastolobuli,SG starch
grain,SL stroma lamellae.Figure is representative from three
different experiments
showed signi?cant recovery and the chlorophyll contents were very close to the control levels (Fig.1).
Exposure of barley plants to 5l M Cd for 15days reduced the net photosynthetic rate (P n ),stomatal con-ductance (G s ),and transpiration rate (T r )by 40.4,54.5,and 25.7%in Weisuobuzhi and 68.9,66.0,and 44.9%in Dong 17,respectively,compared to the control,whereas intra-cellular CO 2concentration (C i )increased in both genotypes (Supplementary Table 1).When barley plants were treated with SNP in the presence of Cd,Cd-induced carbohydrate metabolism decay was evidently reduced,especially in Dong 17;P n ,G s ,and T r increased by 94.6,23.5,and 21.7%in Dong 17compared to Cd-alone treatment.In We-isuobuzhi,the alleviation effect of NO was detected only with respect to P n .Reduced C i levels were observed in Cd ?NO-treated plants of both genotypes compared with Cd-alone treatment (Supplementary Table 1).Ultrastructure of Chloroplasts and Root Cells
Under normal conditions (control),chloroplasts of barley plants contained dense thylakoids arranged in grana and in membranes interconnecting grana,and their stroma lamellae also had localized starch grains (Fig.1A,D).Exposure to 5l M Cd for 15days resulted in swollen grana/stroma lamellae and loose thylakoid membranes,and the number and size of grana stacking per chloroplast and starch grain decreased signi?cantly compared with the control.Furthermore,increased osmiophilic plastoglobuli and cracked chloroplast membranes were observed.The chloroplast ultrastructural deterioration due to Cd was
more prevalent in Dong 17than in Weisuobuzhi (Fig.1B,E).Cd ?NO treatment markedly increased starch grains and reduced osmiophilic plastoglobuli in both genotypes (Fig.1C,F).
Electron micrographs of meristem cells from 5-l M-Cd-stressed barley seedlings revealed obvious ultrastructural changes,characterized by cracked karyotheca and reduced vacuolar numbers (Fig.2B,E).In contrast,root meristem cells appeared completely developed when exogenous NO was added to the Cd experiment (Fig.2C,F).NO mediated the number of plastids and mitochondria cristae increased in Dong 17,even returning to the normal level of controls (Fig.2D–F).
NO Eliminated Cd-induced Overaccumulation
of O 2?-,H 2O 2,and MDA in Leaves
Overaccumulation of ROS in plant cells is the main effect of Cd toxicity.As shown in Supplementary Fig.S3,5l M
Cd treatment induced a dramatic increase in O 2?-and H 2O 2production in the leaves of barley seedlings compared with controls,with a much more severe reaction in the sensitive Dong 17than in the tolerant Weisuobuzhi.Addition of NO signi?cantly diminished Cd-induced ROS accumulation in
leaves of both genotypes,particularly of O 2?-,and returned accumulation to control levels (Supplementary Fig.S3).MDA content was measured as an index of lipid per-oxidation.During the 25-day experiment period,Cd alone induced an increase in MDA content in both genotypes but the increase was greater in the sensitive genotype Dong 17.MDA content from 5l M Cd treatment increased by
51.2%
Fig.2Transmission electron micrograph of root cells of We-isuobuzhi (upper )and Dong 17(below )cultured 15days in basic nutrition (BNS,A ,D ),BNS ?5l M Cd (B ,E ),and BNS ?5l M Cd ?0.25mM SNP (C ,F ).Scale bars =2l M and 1l M.CW cell
wall,E endoplasmic reticulum,M mitochondrion,N nucleolus,P plastid,SG starch grain,V vacuole.Figure is representative from three different experiments
in Weisuobuzhi and 65.1%in Dong 17compared to con-trols.Exogenous NO markedly reduced Cd-induced MDA accumulation;on day 25MDA content decreased by 21.1%in Weisuobuzhi and 54.7%in Dong 17compared with Cd treatment (Supplementary Fig.S3).
Effects of NO Donor on Antioxidant Enzymes
SOD activity showed genotype-and time-dependent vari-ations in response to Cd and Cd ?NO treatment (Fig.3).The expression patterns of the two genotypes were strik-ingly different.After 1day,SOD activities in the leaves of the tolerant Weisuobuzhi dropped during Cd stress.It increased dramatically after 5days and continuously decreased until the end of the experiment (25days)(Fig.3A).The SOD activity of the sensitive genotype Dong 17rapidly increased after 1day of Cd treatment,continuously decreased until 15days,and then increased at 25days (Fig.3B).The SNP supplement to the Cd treat-ment had no effect on SOD activity in Weisuobuzhi except for an increase at 15days (Fig.3A),whereas in the sen-sitive Dong 17,the Cd-induced decline in SOD activity was not affected by Cd ?NO treatment at the beginning (one day)and the end of the experiment (25days)but SOD activities were elevated between 5and 15days (Fig.3B).SOD activity in the roots of the tolerant Weisuobuzhi increased signi?cantly after 1day,remained signi?cantly higher than the control until 5days,and dropped back to control levels until it increased again at 25days (Fig.3C).In Dong 17,slight inhibition or no effect was detected through 15days,followed by a signi?cant increase at 25days (Fig.3D).The addition of SNP induced increased SOD activity in the tolerant Weisuobuzhi to a level even higher than Cd-only treatment between 5and 15days,after which SOD activity returned to near control levels (Fig.3C).In Dong 17NO-supplemented plants showed signi?cantly higher SOD activity than the control or Cd-treated plants after 10days of exposure to the end of the experiment (Fig.3D).
Further study of SOD isoenzymes found that Cd stress reduced Mn-SOD activity in the leaves of both genotypes,especially in Dong 17,whereas it increased root Mn-SOD compared with controls after 15days of exposure (Fig.3E).SNP supplementation induced a
signi?cant
Fig.3SOD activity in leaves (upper )and roots (below )of Weisuobuzhi (A ,C )and Dong 17(B ,D )exposed to Cd for different days,and SOD isoenzyme activities (E ).Error bars represent SD values (n =3).Control,Cd,and Cd ?NO correspond to basic nutrition solution (BNS),BNS ?5l M Cd,and BNS ?5l M Cd ?0.25mM SNP,respectively
increase in Mn-SOD activity in the leaves and roots of both genotypes:by35.9%(leaves)and17.7%(roots)in We-isuobuzhi and109.4%and21.6%in Dong17compared to the Cd-alone treatment.Cu/Zn-SOD activity under Cd stress was signi?cantly higher than controls in both geno-types,except in the leaves of Dong17(slightly but not statistically signi?cantly higher than that of control).The addition of NO decreased Cu/Zn-SOD activity in both leaves and roots;in the leaves of Weisuobuzhi,it recovered to control levels,whereas in Dong17,it was signi?cantly lower than controls and Cd-treated plants.
Cd-alone treatment induced an increase in POD activity in both genotypes(Fig.4A–D).During the experiment,the increase ranged from70.4to189.7%in the leaves of Weisuobuzhi,with the highest increase after day1, whereas in Dong17,POD activity increased continuously from17.5%(day1)to77.4%(day25)compared to controls(Fig.4A,B).Addition of NO decreased
the Fig.4Effect of NO on POD activity in leaves(A,B)and roots
(C,D)and CAT activity in leaves(E,F)of two barley genotypes
(left,Weisuobuzhi;right,Dong17)exposed to Cd for different days.
Error bars represent SD values(n=3).Control,Cd,and Cd?NO
correspond to basic nutrition solution(BNS),BNS?5l M Cd,and
BNS?5l M Cd?0.25mM SNP,respectively.Means with a same
letter are not signi?cantly different at P=0.05
Cd-mediated increase in POD activity in the leaves of both genotypes (Fig.4A,B).However,the effect of NO on the response to Cd with respect to POD activity in the roots differed between the genotypes.In Weisuobuzhi,POD activity increased to a higher level than that of Cd-treated plants after 1,10,and 15days,whereas in Dong 17,there was no signi?cant difference compared with Cd-treated plants,except for a decrease after 10days (Fig.4C,D).Leaf CAT activity in the tolerant and sensitive geno-types differed signi?cantly in response to the treatments.At the beginning of Cd exposure,CAT activity decreased signi?cantly in tolerant Weisuobuzhi,reaching control levels by the end of the experiment (25days)(Fig.4E),whereas in the sensitive Dong 17,CAT activity increased more than threefold after 1day,decreased sharply to below control levels between 5and 15days,and recovered to control levels on day 25(Fig.4F).Addition of NO sig-ni?cantly alleviated Cd-induced inhibition of CAT activity in Weisuobuzhi,except on day 10.Similarly,in Dong 17,Cd ?NO markedly increased CAT activity after 5–15days of treatment.There were signi?cant differences between the geno-types with respect to the effects of Cd on APX activity (Fig.5).In the tolerant genotype Weisuobuzhi,leaf APX activity in the Cd-alone treatment increased signi?cantly at the beginning of the experiment (day 1)and at the end of the study period (25days),but decreased slightly on day 5and 15(Fig.5A).Root APX activity was signi?cantly higher than that of controls during the experiment (Fig.5C).In Dong 17,leaf APX activity increased after 1–5days,declined signi?cantly after 10–15days,and recovered to control levels at the end of the experiment (Fig.5B).Root APX activity was affected from day 5to 15,with the largest decrease of 25.2%after 10days of Cd exposure (Fig.5D).SNP supplementation increased APX activity in the leaves of both Weisuobuzhi and Dong 17all the way through the experiment except for day 1(Fig.5A,B).Similarly,exogenous NO increased APX activity in the roots of both genotypes throughout the 25days of exposure except for a reduction at day 25in Weisuobuzhi (Fig.5C,D).
The sAPX of leaves of the two genotypes had similar responses to Cd (decrease)and to SNP
supplementation
Fig.5Effect of NO on APX activity in leaves (upper panel )and roots (bottom panel )of Weisuobuzhi (A ,C )and Dong 17(B ,D )exposed to Cd for different days,and APX isoenzyme activities (E )in leaves.Error bars represent SD values (n =3).Control,Cd,and Cd ?NO correspond to basic nutrition solution (BNS),BNS ?5l M Cd,and BNS ?5l M Cd ?0.25mM SNP,respectively
(increase).The tAPX of the two genotypes had a similar response to Cd (increase)and no signi?cant change com-pared to the Cd treatment when the NO donor was added (Fig.5E).The response of cAPX and mAPX to Cd and Cd ?NO varied between the https://www.doczj.com/doc/3414795004.html,pared with controls,cAPX activity in Weisuobuzhi increased 16.5%under Cd stress,whereas a 30.8%decrease was detected in Dong 17.Addition of NO (Cd ?NO)reduced cAPX activity in Weisuobuzhi to control levels,whereas in Dong 17cAPX activity increased over that of Cd-treated plants and even over that of controls.mAPX activity in We-isuobuzhi decreased with Cd and Cd ?NO treatments;in Dong 17it showed no obvious change under Cd treatment but increased signi?cantly with the addition of NO (Fig.5).Effect of NO Donor on Transcript Levels of Certain Antioxidative Enzymes
Figure 6shows the quantitative real-time PCR (RT-PCR)results of the relative transcript levels of POD ,CAT ,and cAPX for the two genotypes.The 5l M Cd stress upregu-lated CAT1in both roots and leaves of the two genotypes and POD in the leaves of Dong 17and in the roots of Weisuobuzhi by more than tenfold over the controls.However,a signi?cant decrease in cAPX transcripts was observed except in the leaves of Weisuobuzhi,where it remained unchanged from that of the controls.In the
presence of exogenous SNP,transcript levels of root and leaf POD and CAT1and root cAPX in Weisuobuzhi increased markedly compared with Cd treatment,and transcript levels of leaf cAPX showed no signi?cant dif-ference with Cd treatment and controls.However,in Dong 17,only the cAPX level increased;CAT1and leaf POD were downregulated (Fig.6).
Cd Induces NO Production in Roots and Leaves of Barley Seedlings
NO concentration in the leaves of both genotypes increased dramatically after 1day of Cd treatment relative to controls,and it decreased signi?cantly after 10–25days of Cd exposure,especially in the sensitive genotype Dong 17(average of the three sampling dates decreased by 15.0%)(Fig.7A,B).Root NO concentration showed signi?cant differences between genotypes (Fig.7C,D).In We-isuobuzhi,it increased markedly after 1day of Cd treat-ment,became nearly similar with the controls during 5-10days of Cd exposure,and then increased again after 15–25days (Fig.7C).Root NO concentration in Dong 17was similar to that of controls during 1–5days of Cd exposure,increased markedly on days 10–15,and after that decreased sharply (Fig.7D).Exogenous SNP supplements increased NO concentration in leaves and roots of the tol-erant genotype Weisuobuzhi,except for day 15,
compared
Fig.6Effect of NO on the transcript levels of gene expression encoding antioxidant enzymes in leaves (A ,B ,C )and roots (D ,E ,F )of two barley genotypes exposed to Cd for different days.Error bars represent SD values (n =3).Control,Cd,and Cd ?NO correspond to basic nutrition solution (BNS),BNS ?5l M Cd,and BNS ?5l M Cd ?0.25mM SNP,respectively
with controls and Cd treatment (Fig.7A,C).However,in Dong 17,the NO content in the leaves of Cd ?NO-treated plants was lower than in the Cd-alone-treated plants during day 1to day 5period (but was still signi?cantly higher than in controls after 1day),and then remained the same as the Cd-alone-treated plants (Fig.7B).The NO content of the roots of Cd ?NO-treated plants increased on days 1,5,and 25and decreased signi?cantly on days 10and 15compared with Cd-treated plants (Fig.7D).
Leaf NOS activity in both genotypes increased sharply the ?rst day of Cd treatment and then decreased signi?-cantly (Fig.8).At day 1of Cd exposure,NOS activity in Weisuobuzhi and Dong 17was 65.7and 45.7%,respec-tively,higher than in controls,but 30.4and 47.8%lower on average on the later four sampling dates (Fig.8A,B).SNP addition effectively alleviated Cd-induced inhibition of NOS activity in leaves of both genotypes,with a pro-nounced effect in Weisuobuzhi of returning to control levels.NOS activity was induced by Cd in the roots of both genotypes,especially after 10–15days.Root NOS activity in the Cd ?NO treatment increased more than twofold in Weisuobuzhi compared with Cd-alone-treated plants and controls on days 1and 5,and after that it was downregu-lated to lower than the level of the Cd-alone treatment (Fig.8C).In Dong 17,Cd ?NO elevated NOS levels above those of controls and Cd-alone treatment except at 15days (Fig.8D).
As shown in Fig.8E and F,leaf NR activity in the two genotypes was similar during exposure to Cd and Cd ?NO (5–15days).Differences were observed at the beginning and the end of the experiment (Fig.8E,F).NR activity in Weisuobuzhi increased onefold after 1day of Cd exposure compared to the controls,while in Dong 17,5l M Cd induced a marked decline on day 1.After day 1the NR activity of both genotypes tended to decrease to below control levels.Day 25showed differences again in the NR activity of the two genotypes,with Weisuobuzhi showing lower and Dong 17higher enzyme activities than the controls.Exogenous SNP mediated Cd-induced inhi-bition of leaf NR activity in Weisuobuzhi except on day 1,especially on days 5,10,and 25.For example,NR activity on day 25after Cd ?NO treatment was 68.2and 37.6%higher than that after Cd alone and control,respectively.In the sensitive genotype Dong 17,external NO increased
NR
Fig.7NO content in leaves (A ,B )and roots (C ,D )of two barley genotypes (left ,Weisuobuzhi;right ,Dong 17)exposed to Cd for different days and as affected by SNP.Error bars represent SD values (n =3).Control,Cd,and Cd ?NO correspond to basic nutrition solution (BNS),BNS ?5l M Cd,and BNS ?5l M Cd ?0.25mM SNP,respectively
activity after 1–5days of Cd exposure,after which it remained unchanged as that of the Cd-alone treatment (Fig.8E,F).
Discussion
Nitric oxide (NO)as a ubiquitous signal molecule partici-pates in major physiological processes in plant growth and
development,and in response to biotic and abiotic stresses (Besson-Bard and others 2008,2009).In this work we analyzed the possible role of exogenous NO in the modu-lation of the antioxidant defense system and photosynthetic performance against Cd stress in two barley genotypes differing in Cd tolerance.Addition of 0.25mM SNP to 5l M Cd medium (NO ?Cd)effectively alleviated Cd-induced growth inhibition and toxicity in barley seedlings,described as its ability to prevent inhibition of
shoot/root
Fig.8NOS activity in leaves (A ,B )and roots (C ,D )and NR activity in leaves (E ,F )of two barley genotypes (left ,Weisuobuzhi;right ,Dong 17)exposed to Cd for different days and as affected by SNP.NOS activity in the enzyme extraction supernatant solution was assayed by the conversion of L-arginine to L-citrulline in samples with and without the NOS inhibitors of L-NAME (N G -nitro-L-
arginine methyl ester)and L-AG (L-aminoguanidine).Error bars represent SD values (n =3).Means with the same letter are not signi?cantly different at P =0.05.Control,Cd,and Cd ?N O correspond to basic nutrition solution (BNS),BNS ?5l M Cd,and BNS ?5l M Cd ?0.25mM SNP,respectively
dry weight,plant height,root length,and chlorophyll content,achieving a similar growth state as that found in barley seedlings growing under control conditions,espe-cially for the Cd-sensitive genotype Dong17(Fig.1, Supplementary Fig.S1,Supplementary Table S1).Our previous study suggested that decreasing leaf chlorophyll content was one of the most general toxicity effects of Cd on plants(Wu and Zhang2002;Chen and others2008), which was con?rmed again in the present study.A notable reduction of chlorophyll content was detected in the Cd-sensitive genotype Dong17exposed to5l M Cd,whereas there was no alteration in that of the tolerant Weisuobuzhi. Cd-induced chlorophyll synthesis inhibition was signi?-cantly reversed when barley seedlings were treated with exogenous NO(Cd?NO)(Fig.1),accompanied by the recovery of the rate of photosynthesis,which was severely affected by5l M Cd,especially in the sensitive Dong17 (Supplementary Table1).This indicated that NO-mediated improvement in photosynthesis,partly due to increasing chlorophyll synthesis,is important for improving plant Cd tolerance.In addition,5l M Cd obviously damaged the ultrastructure of chloroplasts,characterized by swollen thylakoid membranes,disturbed the shape of chloroplasts, and induced accumulation of osmiophilic plastoglobuli (Fig.1B,E),with Dong17exhibiting much more severe effects.Interestingly,compared with controls,Cd-alone and Cd?NO treatments both led to less starch accumu-lation in chloroplast stroma in the two genotypes,indicat-ing that plants?ghting against Cd stress might be consuming energy.The addition of NO ameliorated Cd-induced damage to leaf and root ultrastructures.Chloro-plasts of Cd?NO-treated plants recovered,becoming similar to those of the control plants(Fig.1C,F).Root meristem cell ultrastructural observations also revealed a protective effect of NO against Cd-induced swollen mito-chondria and plastids with fewer cristae(Fig.2).These results indicate that NO-mediated stability and integrity of the subcellular structure of barley seedlings under Cd stress contribute to its effective role in preventing Cd-induced leaf chlorosis and inhibition of photosynthesis and growth in barley seedlings.
Reactive oxygen and nitrogen species such as O2?-, H2O2,and NO are often produced in large quantities by plants during various stress responses.We investigated the involvement of these molecules in our experiment.Results of histochemical staining and MDA content showed that Cd-caused overaccumulation of O2?-,H2O2,and MDA in leaves of barley seedlings was markedly eliminated by the addition of NO(Supplementary Fig.S3),especially in Dong17.Moreover,the pattern of alteration in certain antioxidant enzymes induced by Cd stress was counter-acted in the presence of SNP(Cd?NO)(Laspina and others2005;Song and others2006).We obtained similar results in our experiments;for example,addition of 0.25mM SNP signi?cantly elevated the depressed SOD, APX,and CAT activities in Dong17after10and15days of treatment and suppressed the dramatic increase of POD activity toward control levels in both genotypes(Figs.3,4, 5).Thus,it might be deduced that NO indirectly scavenges ROS accumulation by elevating Cd-decreased SOD,APX, and CAT activities,which may account in part for its alleviating effect on Cd-induced oxidative damage in bar-ley seedlings.In addition,according to different subcellular locations and metabolic functions,certain oxidative enzymes always can be distributed in several individual forms(Bowler and others1992).Thus,individual forms of SOD and APX responding to Cd stress and affected by exogenous NO were detected in this study.SOD isoenzyme analysis showed that Mn-SOD activity decreased in the leaves and Cu/Zn-SOD activity simultaneously increased in the leaves and roots of barley seedlings under Cd stress. Thus,the decrease in total SOD activity in leaves under Cd stress is conceivably due to the decrease of Mn-SOD activity.Moreover,Cd-induced Mn-SOD reduction was signi?cantly elevated by the addition of NO(Cd?NO), indicating that NO protection of Mn-SOD activity from Cd-induced inactivation is important for its role in scav-enging ROS under Cd stress(Fig.3).In addition,different patterns of activity of four individual forms of APX were observed in barley leaves under Cd stress.More interest-ingly,cAPX activity exhibited a genotypic difference in both how it responds to Cd stress and the addition of NO (Fig.5E).NO upregulated the Cd-induced decrease in cAPX activity in Dong17and downregulated the increased level in Weisuobuzhi,indicating that maintaining a feasi-bly high cAPX level is bene?cial for plant Cd tolerance, and cAPX might participate in NO-mediated Cd detoxi?-cation(Fig.5E).
Lamattina and others(2003)reported that NO might regulate the expression of antioxidative genes to stimulate the relative enzyme activities.NO-regulated antioxidant enzyme(for example,APX,CAT)gene activation was observed in Arabidopsis suspension cells(Huang and oth-ers2002).However,the mechanism of NO-mediated alteration of the antioxidative enzyme activities is still not clear.In the present study,the alteration of the transcript levels of some antioxidant enzymes induced by Cd and NO was detected by qRT-PCR analysis(Fig.6).Results showed that the addition of NO upregulated the tran-script levels of leaf/root POD,CAT1,and root cAPX in Weisuobuzhi compared with Cd-alone treatment,whereas in Dong17,only cAPX transcript levels increased and transcription of CAT1and leaf POD was downregulated. The obvious discrepancy between expression and activity of POD and CAT might be due to the presence of multiple allo-or isoenzymes or enhanced post-translational
modi?cation(Smeets and others2008).The results of the analysis of cAPX transcript levels and enzyme activity showed good agreement between the gene expression data and the measured enzyme activity in the leaves of the two barley genotypes during Cd stress and NO addition(Figs.5 and6).Such results suggested that the protective effect of NO in Cd toxicity is at least partly related to its role in upregulating the expression of genes encoding antioxida-tive enzymes under Cd stress and subsequently eliminating Cd-induced ROS accumulation.
Recently,Cd-mediated NO production has been found in some plant species(Groppa and others2008;Besson-Bard and others2009).We also investigated the importance of NO production in Cd tolerance.In barley seedlings exposed to5l M Cd,the NO content dramatically increased in the roots and leaves of Cd-tolerant Weisuobuzhi and in the leaves of Cd-sensitive Dong17after1day of treatment compared with controls,whereas no difference was found in the roots of Dong17(Fig.7).Furthermore,two main enzymes involved in NO production of NR and NOS-like enzymes showed a consistent increased pattern of NO synthesis response to Cd with the activity of NOS-like enzymes in the leaves of both genotypes after1day of treatment(Fig.8A–D).However,Cd induced a genotype-dependent change in NR activity in the leaves of barley seedlings after1day of Cd exposure(Fig.8E,F),that is,an increase in the tolerant genotype but a decrease in the sensitive genotype.These results demonstrated the role of NO synthesis in the Cd tolerance of barley seedlings and the important role of NR and NOS-like enzymes in NO syn-thesis(Garcia-Mata and others2003).The Cd-induced increase in NR activity might be related to the Cd tolerance of Weisuobuzhi.Delledonne and others(2001)reported that the cytoprotective role of NO is based mainly on its ability to maintain the cellular redox homeostasis and regulate the level and toxicity of ROS.Meanwhile,an antioxidant function of NO in Cd-stressed plants may be carried out by a direct scavenging of O2?-(Singh and others2004),resulting in a reduced amount of O2?-,as shown in Supplementary Fig.S3.However,this ability of NO to exert a protective function against Cd-caused oxidative stress might also be due to the following pathway:reaction with lipid radicals and then blocking the propagation of lipid oxidation,and activation of antioxidant enzymes such as SOD(especially Mn-SOD for sensitive genotype Dong17),APX(especially cAPX in Dong17),and CAT.
In summary,exogenous NO dramatically depressed ROS and MDA accumulation,compared with5l M Cd treatment,ameliorated Cd-induced damage to leaf and root ultrastructure,and increased chlorophyll content,P n,G s, and T r,thus improving photosynthesis ef?ciency.Mean-while,exogenous NO counteracted Cd-induced time-and genotype-dependent responses of antioxidant enzymes via suppressing a Cd-induced dramatic increase in POD activity in the shoots of both genotypes and recovery to near control values,and by elevating Cd-depressed APX and CAT activities in Dong17after10and15days of exposure.Examination of APX and SOD isoenzymes in leaves revealed the NO signi?cantly increased sAPX and Mn-SOD activities in both genotypes,strongly stimu-lated the Cd-induced decrease in cAPX in the sensitive genotype,and downregulated the increased level in Weisuobuzhi.The results of RT-PCR showed that POD, CAT1,and cAPX responded to Cd stress at the transcript level.External NO upregulated root and leaf cAPX and leaf CAT1expression in Dong17to achieve stimulation.In addition,Cd induced NO synthesis by stimulating NR and NOS-like enzymes in roots and leaves of barley seedlings.
A Cd-induced NO burst in the roots of Weisuobuzhi (Cd-tolerant genotype),but not in that of Dong17 (Cd-sensitive genotype),partly contributed to its Cd toler-ance.Our results demonstrated that improved photosynthe-sis ef?ciency and the membrane-stabilizing/integrity effect could be the principal protective mechanism for exogenous NO in cytoprotection against Cd toxicity.The results also suggested the potential for NO as a potent antioxidant in plants and that its action may,at least in part,be explained by its ability to directly and indirectly scavenge ROS.
Acknowledgments This project was funded by the National Natural Science Foundation of China(30571097),the Project of Sino-Danish Scienti?c and Technological Cooperation(AM14:64/NPP35),and the Special Foundation for the Winner of National Excellent Doctoral Dissertation,the Ministry of Education of China(200556).We deeply appreciate Ms.Jianghong Zhao and Mr.Yuanlong Li,from985-Institute of Agrobiology and Environmental Science(985-IAES)of Zhejiang University,for their kind help with the experiment. References
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第一章教育与教育学 1、《学记》——“教也者，长善而救其失者也” 2、战国时荀子——“以善人者谓之教” 3、许慎在《说文解字》中认为“教，上所施，下所效也。”“育，养子使作善也。” 4、最早将“教育”一词连用的则是战国时期的孟子：“得天下英才而教育之，三乐也。” 5、分析教育哲学的代表人物谢弗勒在《教育的语言》中把教育定义区分为三种： 规定性定义：作者自己认为的定义，即不管他人使用的“教育”的定义是什么，我认为“教育”就是这个意思。运用规定性定义虽然有一定的自由度，但是，要求作业在后面的论述和讨论中，前后一贯地遵守自己的规定。 描述性定义：回答“教育实际上是什么”的定义。尽量不夹杂自己的主观看法，适当地对术语或者使用该术语的方法进行界定。 纲领性定义：回答“教育应该是什么”的定义。即通过明确或隐含的方式告诉人们教育应该是什么或者教育应该怎么样。 6、教育是一种活动。“教育”是以一种“事”的状态存在，而不是以一种“物”的状态出现。因而。我们就把“活动”作为界定教育的起点。 7、教育活动是人类社会独有的活动。 8、“生物起源论”代表人物： 利托尔诺在《各人种的教育演变》中指出教育是超出人类社会以外的，在动物界中就存在的。 沛西·能在《教育原理》中也认为教育是一个生物学过程，扎根于本能的不可避免的行为。 9、“终身教育”概念的提出，指明人在生理成熟后仍继续接受教育。 10、社会性是人的教育活动与动物所谓“教育”活动的本质区别。 11、教育的本质：教育活动是培养人的社会实践活动。 12、教育是人类通过有意识地影响人的身心发展从而影响自身发展的社会实践活动。 13、学校教育是一种专门的培养人的社会实践活动。 14、学校教育自出现以来就一直处于教育活动的核心。 15、学校教育是由专业人员承担的，在专门机构——学校中进行的目的明确、组织严密、系统完善、计划性强的以影响学生身心发展为直接目标的社会实践活动。 16、学校教育的特征：①可控性②专门性③稳定性 17、教育概念的扩展——大教育观的形成 18、1965年，法国教育家保罗·朗格朗在《终身教育引论》中指出，教科文组织应赞同“终身教育”的原则。 19、1972年，埃德加·富尔在《学会生存》中对“终身教育”加以确定，并提出未来社会是“学习化社会”。 20、“终身教育”概念以“生活、终身、教育”三个基本术语为基础。 从时间上看，终身教育要求保证每个人“从摇篮到坟墓”的一生连续性的教育过程； 从空间上看，终身教育要求利用学校、家庭、社会机构等一切可用于教育和学习的场所； 从方式上看，终身教育要求灵活运用集体教育、个别教育、面授或远距离教育； 从教育性质上看，终身教育即要求有正规的教育与训练，也要求有非正规的学习和提高，既要求人人当先生，也要求人人当学生。 21、教育的形态，是指教育的存在特征或组织形式。 22、在教育发展史上，教育的形态经历了从非形式化到形式化，再到制度化教育的演变。
教育学有关理论、代表人物 1、神话起源说—— 2、生物起源说——利托尔诺（法国） 3、心理起源说——孟禄（美国） 4、劳动起源说——马克思（前苏联） 5、中国史上第一部教育文献——《学记》——乐正克 6、西方较早讨论教育问题的着作——《论演说家的培养》（《雄辩术原理》）——昆体良（古罗马） 7、非制度化教育思潮——库姆斯、伊里奇 8、雄辩与问答法——苏格拉底（古希腊） 9、《理想国》——柏拉图（古希腊） 10、《政治学》——亚里士多德（古希腊） 11、教育学作为一门独立学科的萌芽——《大教学论》——夸美纽斯（捷克） 班级授课制，泛智教育。 12、首次提出把教育学作为一门独立的学科——培根（英国） 13、自然主义教育——《爱弥儿》——卢梭（法国） 14、教育学进入大学讲坛——康德（德国）、《林哈德与葛笃德》——裴斯泰洛齐（瑞士）
15、科学教育思潮的兴起，课程体系——《教育论》——斯宾塞（英国） 16、实验教育学——梅伊曼、拉伊（德国） 17、发展性教学理论——《教育与发展》——赞科夫（前苏联） 高难度进行教学的原则、高速度进行教学的原则、理论知识主导作用原则（重理性原则）、理解学习过程原则、对差等生要下功夫的原则 18、范例教学——瓦.根舍因（德国） 19、和谐教育思想——苏霍姆林斯基（前苏联） 20、《教育漫话》——洛克（英国） “白板说”、绅士教育、国民教育思想与民主教育思想。 22、规范教育学的建立——《普通教育学》——赫尔巴特（德国） 传统教育学代表、教师中心，教材中心，课堂中心、四段教学法、统觉观念。 23、实用主义教育学——《民本主义与教育》——杜威（美国） 现代教育学代表、教育即生长，教育即生活，教育即经验的改造或重组、在做中学、儿童中心主义。 24、第一部马克思主义的教育学着作——《教育学》——凯洛夫（前苏联） 25、我国第一部马克思主义的教育学着作——《新教育大纲》——杨贤江 26、设计教学法——克伯屈（美国）
教育心理学理论 一、学习分类理论 1、加涅 （1）学习八水平分类 按学习水平简繁程度分为：①信号学习；②刺激—反应学习；③连锁反应；④言语联想学习；⑤辨别学习；⑥概念学习；⑦规则学习；⑧解决问题学习 （2）学习六水平分类 ①连锁学习；②辨别学习；③具体概念学习；④定义概念学习；⑤规则学习；⑥解决问题学校 （3）学习结果分类 ①言语信息的学习；②智慧技能的学习；③认知策略的学习；④态度的学习；⑤运动技能的学习 2、奥苏贝尔学习性质分类（两个维度互不依赖、相互独立） （1）根据学习的方式：接受学习、发现学习 （2）根据学习材料与学习者原有知识结构的关系：有意义学习、机械学习 3、我国学习结果的分类 ①知识学习；②技能学习；③道德品质或行为习惯的学习 二、学习理论 1、联结理论 （1）经典条件反应论 ①巴甫洛夫：学习就是形成刺激与反应之间的联系 一级条件反射、二级条件反射 动力定型：大脑皮层对刺激的定型系统所形成的反应定型系统 外抑制、超限抑制、消退、泛化、分化 正诱导：一个部位发生抑制引起周围发生兴奋地过程。 负诱导：一个部位发生兴奋引起周围发生抑制的过程。 同时诱导、继时诱导 第一信号系统：能够引起条件反应的物理性的条件刺激。 第二信号系统：能够引起条件反应的以语言符号为中介的条件刺激。 ②华生：通过建立条件作用，形成刺激与反应间的联结的过程。遵循频因律、 近因律。（学习的实质在于形成习惯） （2）操作性条件说 ①桑代克（联结试误说）：在一定的情景和一定的反应之间建立联结，这种联结 通过尝试错误的过程而自动形成。三条学习规律：效果率、练习律、准备率②斯金纳 正强化、负强化、消退 惩罚：惩罚Ⅰ呈现厌恶刺激；惩罚Ⅱ消除愉快刺激 普雷马克原理：用学生喜爱的活动去强化学生参与不喜爱的活动。 强化程式：连续强化程式（灯一开就亮）； 间接强化程式：a 定时强化（按时发工资） b 定比强化（计件工作） c 变时强化（随堂测验）d 变比强化（买彩票） （3）社会学习理论（班杜拉） 学习分为参与性学习和替代性学习（通过观察别人而进行的学习。） 观察学习：注意——保持——复制——动机
1.桑代克的尝试——错误说 刺激——反应联结 基本规律：效果律练习律准备律 2.巴普洛夫——经典性条件作用论俄国 没有食物，只有铃声产生的唾液是条件刺激 看到食物就产生唾液是无条件反应 基本规律：获得与消退刺激泛化（对事物相似性的反应）与分化（对事物差异性的反应） 3.斯金纳——操作性条件作用论 基本规律：强化（+-）逃避条件作用和回避条件作用（负强化）消退惩罚 4.加涅——信息加工学习理论 模式——信息流控制结构（期望执行控制） 5.1-4属于联结学习理论 6.7-10属于认知学习理论 7.苛勒——完形、顿悟说 德国基本内容：学习是通过顿悟过程实现的学习的实质是在主体内部构成完形 8.布鲁纳——认知、结构学习理论 美国学习的目的在于以发现学习的方式，使学科的基本结构转变为学生头脑中的认知结构。 学习观——实质是主动地形成认知结构过程包括获得转化评价教学观——目的在于理解学科的基本结构 教学原则——动机原则结构原则程序原则强化原则 9.奥苏泊尔——有意义的接受学习美国 学习方式分类：接受学习发现学习 学习材料与原有知识结构分类：机械学习意义学习 先行组织者：是先于学习任务本身呈现的一种引导性材料，他的抽象，概括和综合水平高于学习任务，并且与认知结构中原有的观念和新的学习任务相关联。 10.建构主义学习理论
学习动机 1.学习动机的两个基本成分：学习需要学习期待 2.奥苏泊尔学校情境中的成就动机： 认知内驱力（要求理解掌握事物内部动机） 自我提高内驱力（个人学业的成就“三好学生”） 附属内驱力（获得教师、家长的赞扬） 在儿童早期，附属内驱力最为突出 在青年期，认知内驱力和自我提高内驱力成为学习的主要动机 学习期待就其作用来说就是学习诱因 3.学习动机的种类： 社会意义：低级动机（个人、利己主义） 高尚动机（利他主义） 与学习活动的关系：近景的直接性动机（兴趣、爱好、求知欲） 远景的间接性动机（个人前途，父母期望）动力来源：内部动机（个体需要引起） 外部动机（由外部诱因引起） 4.学习动机理论 强化理论：外部强化自我强化 需要层次理论：美国马斯洛五需要（从低级到高级排列） 生理的需要安全的需要归属和爱的需要 尊重的需要自我实现的需要自我实现的需要包括：认知审美创造的需要（最高级的需要）成就动机理论：代表人：阿特金森 力求成功的动机避免失败的动机 成败归因理论：美国维纳三维度六因素 6因素：能力高低努力程度任务难度运气好坏身心状态外界环境3维度：稳定性可控性内在性 自我效能感理论：美国班杜拉 人的行为受行为的结构因素与先行因素的影响。 行为的结果因素就是通常所说的强化： A.直接强化：外部因素（惩罚奖励） B.替代性强化：通过一定的榜样 C.自我强化：自我评价自我监督 5.学习动机的激发：
中学教育心理学考试测试题第三章学习的基本理论 一、单项选择题(下列各题所给选项中只有一个符合题意的正确答案，答错、不答或多答均不得分) 1．根据学习的定义，下列属于学习的现象是( D )。 A．吃了酸的食物流唾液 B．望梅止渴 C．蜘蛛织网 D．儿童模仿电影中人物的行为 2．对黑猩猩做“顿悟实验”的是( A )。 A．苛勒 B．托尔曼 C．桑代克 D．巴甫洛夫 3．加涅提出了( A )模式。 A．积累学习 B．发现学习 C．观察学习 D．接受学习 4．操作性条件反射学说的代表人物是( A )。 A．斯金纳 B．巴甫洛夫 C．桑代克 D．班杜拉 5．美国心理学家布鲁纳认为学习的实质在于( B )。 A．构造一种完形 B．主动地形成认知结构 C．形成刺激与反应间的联结 D．对环境条件的认知 6．( B )强调学习的主动性和认知结构的重要性，主张教学的最终目标是促进学生对学科结构的一般理解。A．斯金纳 B．布鲁纳 C．苛勒 D．加涅 D A D 10．下列不属于意义学习的条件的一项是( D ) A．材料本身必须具有逻辑意义 B．学习者认知结构必须具有能够同化新知识的适当的认知结构 C．学习者必须具有积极主动地将新知识与认知结构中的适当知识加以联系的倾向性，并使两者相互作用D．学习材料要高于学习者的能力范围 11．( A )学习理论认为学习是学生建构自己的知识的过程，学生是信息意义的主动建构者。 A．建构主义 B．认知一结构 C．信息加工 D．尝试一错误 12．“一朝被蛇咬，十年怕井绳”，这种现象指( C )。 A．消退 B．刺激比较 C．刺激泛化 D．刺激分化 13．根据经典条件反射作用理论，食物可以诱发狗的唾液分泌反应，则唾液是( C )。 A．中性刺激 B．无条件刺激 C．条件反应 D．无条件反应 14．看见路上的垃圾后绕道走开，这种行为是( C )。 A．强化 B．惩罚 C．逃避条件作用 D．消退 15．先行组织者教学技术的提出者是美国著名心理学家( C )。 A．斯金纳 B．布鲁纳 C．奥苏伯尔 D．桑代克 二、多项选择题(下列各题所给选项中有两个或两个以上符合题意的正确答案，不答、少答或多答均不得分) 1．学习的定义说明( ABD )。 A．学习是行为或行为潜能的变化 B．学习引起的变化是持久的 C．学习引起的变化是短暂的 D．学习是由反复经验引起的
教育心理学家的基本理论 1、行为学派（刺激——反应联结学习理论） 2、认知学派（认知结构学习理论） 3、掌握学习和指导学习理论 4、人本主义的学习理论 5、精神分析学派 一、行为学派（刺激——反应联结学习理论 1、桑代克 A：学习理论（三条基本学习规律）（P136） ①准备律 ②练习律——应用律、失用律 ③效果律 B：迁移 ①迁移一词的提出（P209） ②共同要素论（P215） C：1903年著《教育心理学》是教育学心理学成为独立学科的开始 D：1913年，将《教育心理学》扩展《教学心理学大纲》，共分为人的本性、学习心理、个别差异及原因。（P8） 2、巴甫洛夫——经典条件反射学习理论 A：消退（P140） B：恢复 C：类化（P140）——一朝被蛇咬，十年怕井绳 D：分化（P140） E：高级条件反射——刺激强化（P141） 3、斯金纳——操作条件反射学习理论 A：有机体行为分类（P142） ①应答性行为——经典条件反射 ②操作性行为——操作条件反射 B：操作条件反射主要规律（P142） ①假如一个操作发生后，接着给予强化刺激，那么这一类反应今后发生的概率就会增加。 ②由于行为效果的强化是使行为频率增加的根本原因，所以通过对有机体的有选择的强化，就可以使行为朝着所需要的方向发展。 C：程序教学（P157） ①小步子逻辑序列 ②要求学生作出积极反应 ③及时反馈 ④学生自定步调 ⑤低的错误率 4、班杜拉——社会学习理论（P143） A：观察式学习（模仿）（P143） “上行下效”、“耳濡目染”（P144）B：替代性强化（P143、149） “杀鸡儆猴”（P149）C：自我强化（P149）D：符号强化（P144） 二、认知学派（认知结构学习理论） 1、布鲁纳——发现学习理论（P158）1）、主动认知——认为学习是一个主动认知的过程。 2）、语言学习——语言学习是儿童心理发展的关键。 3）、学习过程——重视学习的过程。4）、学习结构——强调形成学习结构。5）、直觉思维——强调直觉思维的重要性。6）、内部激励——强调内部动机的重要性。7）、早期教育——强调基础学科的早期学习。 8）、信息提取——强调信息提取(记忆问题不是贮存，而是提取) 9）、发现学习——提倡发现学习。 ——以早期教育为起点，以开发智力为核心，以学科知识结构为基础，以发现学习为手段，以直觉思维为必备要素，以内部激励为动力的旨在培养科学精英的教学思想。
一、选择题：在每小题给出的四个选项中，只有一项是符合题目要求的，把所选选项前的字母填在题后的括号内。 1．首先打出行为主义心理学旗帜的是（）。 A．巴甫洛夫 B．斯金纳 C．桑代克 D．华生 2．以下心理学家不属于认知心理学派的是（）。 A．苛勒 B．斯金纳 C．布鲁纳 D．奥苏伯尔 3．布鲁纳认为，学生掌握学科的基本结构的最好方法是（）。 A．建构法 B．发现法 C．顿悟法 D．接受法 4．程序性教学实际上是（）理论在实践中的运用。 A．学习的操作性条件作用 B．观察学习
C．认知学习 D．认知同化 5．加涅的信息加工系统中的第二级是（）。 A．感受器 B．感受登记 C．短时记忆 D．长时记忆 6．苛勒在研究黑猩猩的学习时采用的实验是（）。 A．迷箱实验 B．迷津实验 C．叠箱实验 D．“三座山”实验 7．建构主义的理论流派中，在皮亚杰的思想之上发展起来的是（）。A．社会建构主义 B．激进建构主义 C．信息加工建构主义 D．社会主义建构主义 8．建构主义强调，知识的特点具有（）。 A．主观性 B．客观性 C．普遍适应性
D．永恒性 9．将符号所代表的新知识与学习者认知结构中已有的适当观念建立起非人为的和实质性的联系属于（）。 A．机械学习 B．意义学习 C．接受学习 D．发现学习 10．在发现教学中，教师的角色是学生学习的（）。 A．促进者和引导者 B．领导者和参谋 C．管理者 D．示范者 11．孩子哭闹着要买玩具，母亲对其不予理睬，这是（）。 A．正强化 B．负强化 C．惩罚 D．消退 12．以下心理学家及其理论匹配不正确的一项是（）。 A．奥苏伯尔——认知发现说 B．苛勒——完形一顿悟说 C．托尔曼——认知目的说 D．加涅——信息加工理论
第三章学习的基本理论 第一节学习概述 一、学习的含义 (一)广义的学习 1、广义学习的含义：人和动物在生活过程中，凭借经验而产生的行为/行为潜能的相对持久的变化。 2、产生广义学习的三个特征： （1）学习必须使个体产生行为或行为潜能的变化。 （2）这种变化是相对持久的。有些主体的变化，如疲劳，创伤等引起的变化是暂时的，经过一段时间或一旦条件改变就会自行消失，这种变化不能称作学习。 （3）这种变化是由反复经验而引起的。 （二）狭义的学习 1、狭义学习的含义：指人类的学习，指个体在社会生活实践中，以语言为中介，自觉地、积极主动地掌握社会、个体的经验的过程。 2、人类学习与动物学习的本质区别： （1）人的学习是掌握人类社会历史经验、科学文化知识，获得个体行为经验的过程。 （2）人的学习是在社会生活实践中，与他人的交往时，以语言的中介进行的。 （3 3 （1）学生学习的含义：在教师的指导下，有目的、有计划、有组织、有系统地进行的，是在较短的时间内接受前人所积累和科学文化知识，并以此来充实自己的过程。 （2）学生学习内容：①知识、技能和学习策略的掌握，②问题解决能力、创造性的发展，③道德品质和健康心理的培养。 （3）学生学习的特点：①以系统地掌握人类的间接经验为主；②在教师的指导下进行，有较强的计划性、目的性、组织性；③具有一定程度的被动性；④要促进学生全面发展：学生不但要学习知识技能，还要发展智能，培养行为习惯、道德品质和健康的心理。 二、学习的分类 （一）从学习的主体来说，学习可以分为：动物学习、人类学习和机器学习。 （二）按学习的意识水平，[美]心理学家阿瑟.雷伯将学习分为：内隐学习和外显学习。 （三）加涅的学习结果分类：认为学习结果就是各种习得的才能、本领。获得以下五种才能：言语信息、智慧技能、认知策略、态度、动作技能。 1、言语信息的学习：帮助学生解决“是什么”的问题。掌握以言语信息传递的内容，学习结果是以言语信息表现出来的。 2、智慧技能的学习：解决“怎么做”的问题，用以对外界的符号、信息进行处理加工。辨别技能是最基本的智慧技能，按不同的学习水平及其所包含的心理运算的复杂程度，依次为：辨别、概念、规则、高级规则 3、认知策略的学习：学习者用以支配自己的注意、学习、记忆和思维的有内在组织的才能，这种才能使得学习过程的执行控制成为可能。智慧技能指向外部环境，而认知策略指向学习者内部。 4、态度的学习：态度是通过学习获得的内部状态，这种状态影响着个人对某种事物、人物及事件所采取的行动。加涅提出三类态度：（1）儿童对家庭和其他社会关系的认识；（2）对某种活动所伴随的积极的喜爱情感；（3）有关个人品德的某些方面，如热爱国家等。 5、运动技能的学习：运动技能又称为动作技能，也是能力的一个组成部分。
第三章学习的基本理论 一、单选题 1.被誉为现代教育心理学奠基人的是（）。 A桑代克 B.巴甫洛夫 C.斯金纳 D.布鲁纳 2．下列不属于学习引起的变化的是（）。 A. 幼儿会喊爸爸、妈妈 B.青春期嗓音变化 C.骑车 D.会使用电脑 3学习对某种信号作出一般性和弥散性的反应是（）学习。 A.刺激——反应 B.连锁 C.辨别 D.信号 4．属于巴甫洛夫的经典性条件反射的学习类型是( )学习。 A.刺激——反应 B.信号 C.概念 D.连锁 5．属于操作性条件反射的学习类型是( )学习。 A.信号 B.规则 C.解决问题 D.刺激——反应 6联合两个或两个以上的刺激——反应动作，以形成一系列动作联结的学习类型是（）学习。 A. 连锁 B.概念 C.辨别 D. 刺激——反应 7．各类动作技能的形成都离不开（）学习。 A.信号 B.规则 C.连锁 D.刺激——反应 8．对一系列类似的刺激分别作出适当的反应的学习是（）学习。 A.连锁 B.概念 C.辨别 D.规则 9．（）学习是指认识一类事物的共同属性，并对其抽象特征作出反应。 A.解决问题 B.概念 C.辨别 D.规则 10．把鲸鱼、象、狗等概括为“哺乳动物”，这属于（）学习。 A.解决问题 B.概念 C.辨别 D.规则 11．理解“功=力×距离”这一公式，这是（）学习。 A.信号 B.概念 C.辨别 D.原理 12．掌握教育学基本原理后，用之于解决教育中的实际问题，这是（）学习。 A.解决问题 B.规则 C.概念 D.刺激——反应 13．（）是调节和控制自己的注意、学习、记忆、思维和问题解决过程的内部组织起来的能力。 A.智慧技能 B.认知策略 C.动作技能 D.态度 14．（）是使用符合与环境相互作用的能力。 A.智慧技能 B.认知策略 C.言语信息 D.态度 15．（）表现为学会陈述观点的能力。 A.智慧技能 B.认知策略 C.言语信息 D.态度 16．（）是对外的平稳而精确的操作能力。 A.智慧技能 B.认知策略 C.言语信息 D.动作技能 17．（）表现为个体对人、对物或某些事件的意向。 A.智慧技能 B.认知策略 C.言语信息 D.态度 18.在试误学习的过程中，学习者对环境刺激作出反应后能获得满意的结果时，其联结就会增强，这是（）。 A.效果律 B.练习律 C.准备律 D.强化律 19．在试误学习的过程中，刺激与反应的联结，如果练习运用，联结的力量逐渐增大，如果不运用，则逐渐减小，这是( ).。
《教育心理学》学习的基本理论 一、不定项选择题 1．下列属于学习的现象是（）。 A．吃了酸的食物流唾液B．了解低碳生活并付诸行动C．蜘蛛织网D．儿童模仿电影中人物的行为2．一名学生能够运用三角形的面积公式解决一个他从来没有见到过的三角形的面积，这表明他已经具备了（）。 A．言语信息B．动作技能C．智慧技能D．认知策略E．态度 3．某位学生近一段及时完成作业，老师告诉他放学后不必再留在教室里完成作业了，此后该生继续按时完成作业，这时该生受到了（）。 A．正强化B．负强化c．正惩罚D．负惩罚 4．奥苏贝尔提倡的一种学习类型是（）。 A．有意义-发现学习B．有意义-接受学习C．机械-接收学习D．机械-发现学习 5．引导学生分辨勇敢和鲁莽、谦让和退缩属于刺激（）。 A．获得B．消退C．分化D．泛化 6．“孟母三迁”终使孟子成才，能够有效解释该现象的理论是（）。 A．认知学习理论B．社会学习理论C．人本主义理论D．建构主义理论 7．学生学习“功=力×距离”，这种学习属于（）。 A．辨别学习B．符号学习C．概念学习D．规则或原理学习 8．（）指教材被分成若干小步子，学生可自定学习步调，让学生对所学内容进行积极反应，并给予及时强化和反馈使错误率最低。 A．程序教学B．组织教学C．个别化教学D．指导教学 9．（）强调学习的主动性和认知结构的重要性，主张教学的最终目标是促进学生对学科结构的一般理解。 A．布鲁纳B．班杜拉C．桑代克D．巴甫洛夫 10．布鲁纳认为任何知识结构都可以用适合形式呈现，以下不属于他提出的呈现方式的一项是（）。A．动作表象B．图像表象C．符号表象D．情感表象 11．最初主张S-R联结存在意识中介的心理学家或心理学流派是（）。 A．格式塔学派B．布鲁纳C．斯金纳D．托尔曼 12．人和动物一旦学会对某一特定的条件刺激作出条件反应以后，其他与该条件刺激相类似的刺激也能诱发其条件反应，称为（）。 A．刺激分化B．消退C．刺激泛化D．获得 13．操作性条件作用论的提出者是（）。 A．桑代克B．苛勒C．斯金纳D．巴甫洛夫 14．布鲁纳的学习论是（）。 A．完形顿悟说B．有意义接受学习论C．认知结构学习论D．建构主义 15．观察者看到榜样受到强化而如同自己也受到强化一样，这称为（）。 A．外部强化B．自我强化C．直接强化D．替代强化 16．“一朝被蛇咬，十年怕井绳”，这种现象是指（）。
教育心理学考试重点提示:第三章学习的基本理论 重点提示 统观近几年全国各省的教师资格认证教育心理学考试，本章的考查重点是： (1)学习的定义。 (2)学习的主要理论： 尝试一错误学习的基本规律。 经典性条件反射的基本规律。 布鲁纳的认识一结构学习论。 当今建构主义学习理论的基本观点。 考纲链接 1．学习的实质与特征： (1)学习的概念。广义的学习指人和动物在生活过程中，凭借经验而产生的行为或行为潜能的变化。狭义的学习指人类的学习，是在社会生活实践中，以语言为中介，自觉地、积极主动地掌握社会的和个体的经验的过程。 (2)人类学习与动物学习的区别。首先，人的学习除了要获得个体的行为经验外，还要掌握人类世世代代积累起来的社会历史经验和科学文化知识；其次，人的学习是在改造客观世界的生活实践中，在与其他人的交往过程中，通过语言的中介作用而进行的；此外，人的学习是一种有目的的、自觉的、积极主动的过程。 2．学生的学习：是在教师的指导下，有目的、有计划、有组织、有系统地进行，在较短时间内接受前人所积累的科学文化知识，并以此来充实自己的过程。 3．学习内容：一是知识、技能和学习策略的掌握；二是问题解决能力和创造性的发展；三是道德品质和健康心理的培养。 4．加涅关于学习层次和学习结果的分类： (1)加涅关于学习层次分类：信号学习、刺激－反应学习、连锁学习、语言联结学习、辨别学习、概念学习、规则或原理学习、解决问题学习。 8．认知学习理论： (1)完形－顿悟说：由苛勒提出，主要观点：学习是通过顿悟实现的；学习的实质在于构造完形。 (2)认知－结构学习论：由布鲁纳提出。他主张学习的目的在于以发现学习的方式，使学科的基本结构转变为学生头脑中的认知结构。 10．建构主义学习理论。基本观点： (1)知识观。知识并不是问题的最终答案；知识并不能精确地概括世界的法则；知识不可能以实体的形式存在于具
《教育心理学》分章强化题三：第三章学习的基本理论 一、选择题 1.下列现象可以归入到学习中的现象有（）。 A.事故后体会到交通法规的重要性 B.疲劳时记忆力下降 C.乳儿抓住碰到的东西 D.青春期少年的嗓音变化 2.新生渐渐知道铃声代表上课，这属于（）。 A.信号学习 B.辨别学习 C.概念学习 D.言语联结学习 3.各种动作技能的学习，都离不开（）。 A.连锁学习 B.言语联结学习 C.解决问题的学习 D.信号学习 4.使用符号与环境相互作用的能力属于（）。 A.认知策略 B.言语信息 C.动作技能 D.智慧技能 5.在试误学习过程中，当刺激与反应之间的联结不准备实现时，实现则感到烦恼，这符合（）。
A.练习律 B.准备律 C.效果律 D.联结律 6.家长对考试成绩好的孩子给予物质奖励是（）。 A.正强化 B.负强化 C.消退 D.惩罚 7.一个学生上课讲话,老师要他写“我上课讲话，真丑”1000遍，这属于（）。 A.正强化 B.负强化 C.惩罚 D.替代强化 8.认为学习是个体利用本身的智慧与理解力对情境及情境与自身关系的顿悟的学说为（）。 A.认知-结构学习论 B.有意义接受学习论 C.完形-顿悟说 D.建构主义学习论 9.有意义接受学习论的提出者是（）。 A.苛勒 B.布鲁纳 C.斯金纳 D.奥苏伯尔 10.将符号所代表的新知识与学习者认知结构中已有的适当观念建立起非人为和实质性的联系的学习是（）。 A.接受学习 B.发现学习 C.机械学习 D.意义学习 11.认为知识并不是对现实的准确表征，它只是一种解释、一种假设的理论为（或认为学生的学习不仅是对新知识的理解，而且是对新知识的分析、检验和批判的力量是）（）。
第三章学习的基本理论 1）什么是学习？人类学习和动物学习有什么本质的区别？ 广义的学习指人和动物在生活过程中，凭借经验而产生的行为或行为潜能的相对持久的变化。 定义说明：1、学习表现为行为或行为潜能的变化。2、学习所引起的行为或行为潜能的变化是相对持久的。3、学习是由反复经验而引起的。 狭义的学习指人类的学习，指个体在社会生活实践中，以语言为中介，自觉地、积极主动地掌握社会的和个体的经验的过程。 人类学习vs. 动物学习有本质的区别： 1. 人的学习除了要获得个体的行为经验外，还要掌握人类世世代代积累起来的社会历史经验和科学文化知识。 2. 人的学习是在改造客观世界的生活实践中，在与其他人的交往过程中，通过语言的中介作用而进行的。 3. 人类的学习是一种有目的、自觉的、积极主动的过程。 2）学生的学习的内容和特点什么？（人类学习和学生学习有什么区别） 含义：学生的学习是人类学习中的一种特殊形式，它是在老师的指导下，有目的、有计划、有组织、有系统的进行的，是在较短的时间内接受前人所积累的文化科学知识，并以此来充实自己的过程。 学习内容：一是知识、技能和学习策略的掌握；二是问题解决能力和创造性的发展；三是道德品质和健康心理的培养。 人类学习和学生学习之间是一般与特殊的关系，学生的学习既与人类的学习有共同之处，但又有其特点：①以间接经验的掌握为主线；②具有较强的计划性、目的性和组织性；③具有一定程度的被动性。 3）加涅按照学习结果的不同把学习分成那些类型？ 1、言语信息， 2、智慧技能， 3、认知策略， 4、态度， 5、运动技能。 4）简述奥苏贝尔对学习的分类 根据两个维度对认知领域的学习分类：一个是学习进行的方式，分为接受学习和发现学习；另一个维度是学习材料与学习者原有知识的关系，可分为机械学习和有意义学习。这两个维度互不依赖，彼此独立。并且每一个维度都存在许多过渡形式。 5）我国心理学家对学习是怎样分类的？ 分为知识的学习、技能的学习和行为规范的学习三类。 6）联结学习理论的基本观点有哪些？（行为主义） 联结学习理论认为：一切学习都是通过条件作用，在刺激（S）和反应（R）之间建立直接联结的过程。强化在刺激—反应之间的建立过程中起着重要作用。在刺激—反应联结之中，个体学到的是习惯，而习惯是反复练习和强化的结果。习惯一旦形成，只要原来的或类似的刺激情境出现，习得的习惯性反应就会自动出现。 7 桑代克是美国著名心理学家，他采用实证主义的取向，使教育心理学研究走向了科学化的道路，是科学教育心理学的开创者，是第一个系统论述教育心理学的心理学家，被称为“现代教育心理学之父”。是最早用动物实验来研究学习规律的心理学家。 （一）经典实验：猫开笼取食的实验。 （二）学习的联结说（又叫试误说）：通过这类实验，桑代克提出学习不是建立观念之间的联结，而是建立刺激—反应（S—R）联结，即在一定的刺激情境与某种正确反应之间形成联结，其中不需要观念或思维的参与。这种刺激—反应联结主要是通过尝试错误、
昆体良古罗 马 1.《雄辩术原理》世上第一部研究系统的教学方法论著，被公认为是西方教育史上的伟大 教育家，是第一位教学理论家和教学法专家。 2. 最早提出分班教学的思想 杜威美国1.提出实用主义教育学，杜威出版《民主主义与教育》《经验与教育》，克伯屈出版《设计教学法》，提倡活动课。 思想：强调儿童的主体地位：①教育即生活，教育即生长②教育社会化③做中学④教育即经验的不断改造。以儿童为中心，反对教师中心论 2.现代教育代言人现代教育的主要特点是民主 3.教育无目的论“教育是一个社会过程。” 4.问题的解决杜威的五步模式①困惑②诊断③假设④推断⑤验证 5.问题解决步骤的五步模式⑴疑难⑵分析⑶假设⑷检验和评价⑸结论 桑代克 美 国 1.1903年出版西方第一本《教育心理学》，是教育心理学体系的创始，标志着教育心理学 称为一门独立的学科。 2.学习理论之联结派的学习理论——联结学习：尝试－错误说（小猫“迷箱”试验） 试误成功条件：练习律、准备律、效果律 3.教育心理学体系（现代教育心理学）和联结主义学习心理学创始人，被誉为教育心理学 之父 4. 学习迁移理论之联结主义的相同要素说（代表人物：桑代克、伍德沃斯） 桑代克：相同要素说，即学习上的迁移是相同联结的转移。 伍德沃斯：共同成分说，即两种学习活动含有共同成分，则发生迁移，学习也就更容易。 以刺激——反应联结理论为基础。只有当学习情景和迁移情景存在共同成分时，才能产生迁移。即材料相似性是决定迁移的条件 5.现代教育测验之父 6.智力水平越高，迁移越大。 7.问题解决理论之试误说，又称联结说——（猫“迷箱”实验） 问题的解决过程是刺激情境与适当反应之间的联结完成的，联结的建立是通过尝试错误完成的。 贾德美国1.学习迁移理论之机能心理学的经验泛化说—“水下击靶”实验 他认为一个人对他的经验进行了概括，就可以完成从一个情境到另一个情境的迁移。概括就等于迁移，原理、法则等概括化的理论知识对迁移作用很大。 沃尔夫德国 1.学习迁移理论之官能心理学的形式训练说 他把迁移的实质理解为新的官能经训练而发展，认为促进迁移的条件与学习内容无大关系而偏重于形式。 魏特海默 苛勒德国 1.学习理论之认知派学习理论——格式塔的顿悟学习理论（黑猩猩取香蕉实验）：学习是 一个顿悟的过程，是突然察觉到解决问题的办法。主要代表人物：魏特海墨、科夫卡和克勒 2.学习迁移理论之格式塔学派的关系转换说（代表人物：苛勒）—“小鸡啄米实验” 强调“顿悟”是迁移的一个决定因素。强调个体的作用，愈能加以概括化，愈易产生迁移。 3.问题解决理论之顿悟说（苛勒）——黑猩猩取香蕉实验 4.格式塔心理学（完形心理学）创始人魏特海墨、科夫卡和克勒研究内容是意识体验， 论点“整体大于部分之和” 解决问题时从整体把握全部问题情境和认知结构的豁然改组，而不是一次次经验的积累。 反对元素分析认为每一个心理现象都是一个整体是一个格式塔是一个完形 学习的实质在于构造完型，刺激与反应之间的联系而需要意识作为中介 布鲁美国1.结构化教材和发现学习模式（明确结构，掌握课题，提供资料→建立假说，推测答案→验证→做出结论） 2.领导美国20C60y的结构主义课程改革，主张突出学科基本结构，让学生通过发现法学习，重视智力发展（动机原则、结构原则、程序原则、反馈原则） 3.学习理论之现代认知学习理论——认知发现理论 强调认知学习和认知发展，提倡发现学习。学习的核心内容是各门学科的基本知识结构。3教学方法：发现学习，新课标中也叫“探究学习”。即教师提出课题和一定的材料，引导学生自己进行分析、综合、抽象、概括等一系列活动，最后得到学习结果。 4.提出假设考验说，研究人工概念的形成（人需要利用已有的知识主动提出一些可能的假设，即猜想这个概念是什么）——人工概念是认为的、在程序上模拟的概念，这种方法最早是赫尔于1920年首创的。 5.强调非特殊成分的迁移，也叫普遍迁移。即学习了基本的普遍的概念或原理，可作为学
第一章做合格教师 第一部分主要理论知识 1．合格教师心理素质 教师心理素质是教师在专业发展过程中，在心理过程和个性心理特征两方面所表现出来的本质特征。 教师的心理素质包括如下方面，即教师的智力素质、教师的情感素质、教师意志素质、教师的教育教学素质、教师的人格素质、教师的信念。 2、教师的智力素质 教师的智力是从事教育工作应具备的基本心理素质，是教师从事教育教学工作的心理基础。教师的智力素质表现在以下方面： (1)敏锐的观察力(2)良好的记忆力(3)丰富的想象力⑷多方位的立体思维能力 ⑸注意分配的能力 3、教师的情感素质特点 教育过程是师生情感交流的过程，教育工作最大的特点就是以情感人。 (1)成熟而稳定的情感(2)爱的情感：对教育事业的热爱、对学生的热爱、对所教学科的热爱 4、教师的意志特点 (1)实现教育目的的自觉性(2)克服困难的坚韧性(3)选择教育决策的果断性(4)解决矛盾的沉着自制性 4．教师的教育能力素质 因材施教的教育能力、获取信息的能力、独创能力、教育科研能力、心理教育能力、教育机智 5．教师的教学素质：包括教师的知识结构与教学能力。 6．教师的知识结构 教师的知识水平是其从事教学工作的前提条件。根据有关专家的研究，教师的知识结构可由三方面组成，分别为本体性知识、实践性知识和条件性知识。 7．本体性知识。 教师职业的本体性知识是教师所具有的特定的学科知识，如语文知识、数学
知识等，也即人们所熟知的科目知识。 林崇德等人的研究表明，教师的本体性知识与学生成绩之间几乎不存在统计上的关系。 由于学科不同，本体性知识的具体内容是不同的。仅仅从一般意义上说，教师的本体性知识应包括四个方面：教师应对学科的基础知识有广泛而准确的理解，熟练掌握相关的技能、技巧；教师要基本了解与所教学科相关的知识点、相关性质以及逻辑关系；教师需要了解该学科的发展历史和趋势，对于社会、人类发展的价值以及在人类生活实践中的多种表现形态；教师需要掌握每一门学科所提供的独特的认识世界的视角、域界、层次及思维的工具与方法等。 8．实践性知识 教师的实践性知识是教师在开展有目的的教育教学活动过程中解决具体问题的知识，是教师教育教学经验的积累和提炼，它主要来源于课堂教育教学情景之中和课堂内外的师生互动行为，带有明显的情景性、个体性，体现出教师个人的教育智慧和教学风格。研究表明，教龄对教师的实践性知识存在着显著影响，教师的实践性知识水平随着教龄的增加而逐步上升。 9．条件性知识 教师的条件性知识是指教师所具有的教育学与心理学知识。条件性知识是：个教师成功教学的重要保障，而这种知识是目前广大的一般教师所普遍缺乏的。教师的条件性知识分为三个方面，即学生身心发展的知识、教与学的知识和学生成绩评价的知识。 正如杜威指出的那样，科学家的学科知识与教师的学科知识是不一样的，教师必须把学科知识“心理学化”，以便学生能理解。 10．教师的教学能力 教师的教学能力是教师从事教学活动，完成教学任务的能力，是教师专业能力的重要方面。 ⑴教学认知能力⑵教学设计的能力 ⑶教学操作能力：①表达能力②课堂组织管理能力③运用现代教育技术的能力