冠菌素对玉米幼苗耐干旱胁迫的诱导效应

以玉米幼苗为材料,在20%PEG模拟干旱条件下,研究了植物生长物质冠菌素0.001~1.0μmol?L-1处理时叶片水分状况及其脯氨酸、可溶性糖、MDA含量及抗氧化酶活性.实验表明,在干旱胁迫条件下,低浓度(0.01μmol?L-1)的冠菌素处理能显著降低干旱胁迫下叶片水势,并显著提高玉米幼苗叶片相对含水量、可溶性糖和游离脯氨酸的含量;同时能显著提高玉米叶片中POD、CAT和APX的活性(分别比对照高32.1%、13.8%和29.5%),而对SOD和GR的活性无显著影响;此时叶片中MDA的含量显著比对照降低11.6%,能够在一定程度上维持细胞膜的完整性.高浓度冠菌素处理(1.0μmol?L-1)下各指标的变化趋势则相反.结果证明,低浓度冠菌素(0.01μmol?L-1)能增强玉米幼苗耐干旱胁迫的能力.     

大豆幼苗对套作玉米遮荫环境的光合生理生态响应

以2个耐荫性不同的大豆品种为材料,田间试验设置大豆单作和玉米-大豆套作2个种植模式处理,研究不同耐荫性大豆品种的幼苗光合生理生态特性对套作玉米遮荫环境的响应。结果表明:1)玉米-大豆套作模式中,玉米遮荫显著降低大豆冠层的光合有效辐射,导致大豆幼苗光合速率、气孔导度、蒸腾速率显著下降(P0.05),分别达37.9%、54.2%和42.4%,但品种间无显著差异;而胞间二氧化碳浓度和Fv/Fm无显著变化,且光合速率的下降与气孔导度存在显著相关关系,光合速率下降主要是由气孔限制和CO2同化过程中能量不足所致;2)玉米遮荫显著降低大豆幼苗叶面积指数、叶片碳含量、叶片和根系干重及总生物量,且品种间差异显著,相关性分析显示,叶面积指数下降是导致生物量减少的主要原因;3)玉米遮荫环境中,大豆幼苗的叶片叶绿素和氮素含量提高以增强光捕获能力,但它们并不能补偿因光截获面积降低而引起的光截获量下降。     

壳聚糖对镉胁迫下玉米幼苗根系抗氧化酶活性和内源激素水平的影响

为探究壳聚糖对增强玉米幼苗抗镉胁迫能力的生理生化机制,以玉米(Zea mays L.)杂交种‘郑单958’为试验材料,采用室内Hoagland水培法,探讨外施100mg·L~(-1)壳聚糖对镉胁迫(80mg·L~(-1))不同时间(0h、24h、48h、72h和96h)下玉米幼苗根系抗氧化酶活性和内源激素水平的影响。结果显示:(1)镉胁迫显著抑制玉米幼苗根系生长,并诱导根系活性氧产生、抗氧化酶活性增加、内源激素的平衡受到破坏。(2)镉胁迫下,外施壳聚糖处理96h后根系干重提高16.1%,根系的O-·2产生速率和H2O2含量分别降低9.1%和19.2%,SOD、POD和CAT活性分别提高32.5%、20.4%和21.3%,IAA、ZR和GA含量分别增加34.4%、40.4%和42.5%,ABA含量减少19.1%,IAA/ABA、ZR/ABA和GA/ABA分别提升66.1%、73.5%和76.0%。研究表明,壳聚糖能够调控镉胁迫下玉米幼苗根系内源激素的含量及平衡,减轻胁迫对抗氧化酶系统的破坏,增强其清除活性氧的能力,从而降低镉胁迫对根系的毒害,提高玉米幼苗对镉胁迫的抵抗能力,为玉米抗逆栽培提供了理论及试验依据。     

5-羟色胺在红树植物秋茄幼苗抗寒中的作用

5-羟色胺(5-HT)不仅能参与植物的生长发育,还可以延缓衰老及应对非生物胁迫。为探明5-HT在调控红树林抗寒中的作用,以红树植物秋茄为试验材料,研究抗寒锻炼和喷施DL-4-氯苯丙氨酸(p-CPA, 5-HT合成抑制剂)对低温胁迫下秋茄幼苗叶片气体交换参数、CO₂响应曲线(A/Ca)和内源植物激素含量的影响。结果表明：低温胁迫显著降低了秋茄幼苗叶片5-HT、叶绿素、内源生长素(IAA)、赤霉素(GA)和脱落酸(ABA)含量,减弱了其利用CO₂的能力,降低了净光合速率,抑制了初始羧化效率。低温胁迫下施用外源p-CPA降低了秋茄幼苗叶片光合色素、内源各激素和5-HT含量,加剧了低温胁迫对秋茄幼苗叶片光合功能的伤害。抗寒锻炼可有效降低低温胁迫下秋茄幼苗叶片内源IAA含量,促使植株产生更多的5-HT,提高了叶片光合色素、GA、ABA含量和初始羧化效率,提升了光合碳同化能力,最终提高了秋茄幼苗叶片的光合作用;抗寒锻炼下喷施p-CPA会显著抑制秋茄幼苗叶片5-HT合成,促进IAA产生,同时降低光合色素、GA、ABA含量和初始羧化效率,减弱抗寒锻炼对红树林...     

蓝光对水稻幼苗生长及内源激素水平的影响

研究表明：与白光对照相比,蓝光明显抑制水稻幼苗的生长,并使幼苗体内的自由态IAA、GA1、玉米素和二氢玉米素含量下降,ABA含量和乙烯释放量则明显增加。说明蓝光对水稻幼苗生长的影响与其体内激素状况有关。     

复合外源物质对玉米幼苗抗寒性的影响

该研究采用不同浓度的水杨酸(SA)、脱落酸(ABA)、磷酸二氢钾(KH2PO4)以及抗坏血酸(VC)进行正交组合获得不同浓度组合的复合外源物质,同时以蒸馏水处理作为对照,将其喷施于玉米幼苗后进行低温胁迫处理,在胁迫结束后使幼苗恢复生长,并测定叶片相关生长指标及生理生化指标的变化。结果表明:(1)与对照组相比,9种复合外源物质处理均可显著提高玉米幼苗的相对生长速率、干物质积累速率及脯氨酸含量,降低相对电导率,总体上提高了玉米幼苗的素质。(2)在4℃低温胁迫下,9种复合外源物质处理下幼苗相对生长速率、干物质积累速率、根系活力、脯氨酸含量、可溶性蛋白含量及可溶性糖含量,均显著高于对照,并减缓了丙二醛的积累和相应的膜脂过氧化,降低了相对电导率,提高了玉米幼苗的耐冷性。低温胁迫条件下,水杨酸、脱落酸、磷酸二氢钾和抗坏血酸四种物质组成的复合物可以提高玉米幼苗的耐冷性,其中以SA0.14 g·L~(-1)+ABA 0.015 g·L~(-1)+KH_2PO_4 3.0 g·L~(-1)+V_C 3.0 g·L~(-1)的复合物效果最好。该研究结果为新型复合抗寒剂的应用推广提供了技术支持。     

一氧化氮参与调节盐胁迫诱导的玉米幼苗脱落酸积累

以三叶一心期的玉米幼苗为实验材料,研究了盐胁迫下玉米幼苗根尖和叶片中一氧化氮（NO）和脱落酸（ABA）积累之间的关系。结果表明,盐胁迫下玉米幼苗NO和ABA的含量均增加,用NO供体硝普钠（Sodium nitroprusside,SNP）处理时,ABA含量亦增加,且累积的时间较盐胁迫下早。用NO合成的抑制剂L-NAME （Nω-nitro-L-arginine methyl ester hydrochloride）和NaN,处理时,可减弱盐胁迫诱导的ABA含量的增加,用NO清除剂cPTIO处理时,这种盐胁迫诱导的ABA增加减少。推测盐胁迫下产生的NO参与调节ABA的积累及逆境下植物的防御反应。     

外源ABA对楸树幼苗NaCl胁迫的缓解效应及其生长生理响应特征

以2年生楸树(苏楸1号和008-1)扦插苗为材料,采用盆栽试验法,分析盐胁迫(0.5%NaCl)处理下楸树幼苗生长、生理的变化,并分析不同浓度外源ABA(15、25、35 mg/L)对盐胁迫(30 d)楸树幼苗的缓解效应及其生理生化特性,以探索重度盐胁迫下适合楸树幼苗生长的适宜外源ABA浓度,为增强盐碱地楸树的耐盐性、提高盐碱地的利用提供理论依据。结果显示:(1)0.5%NaCl胁迫下,两品种楸树幼苗叶片表现出不同程度的盐害症状,且‘苏楸1号’叶片盐害症状较‘008-1’严重;随胁迫时间延长,两品种楸树幼苗的相对电导率(REC)均呈先上升后下降的变化趋势,叶绿素(Chl)、相对含水量(RWC)均呈降低趋势,可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)以及超氧化物歧化酶(SOD)活性均呈先上升后下降趋势,但‘008-1’的REC显著低于‘苏楸1号’,Chl、RWC、SS、SP、Pro、SOD均显著高于苏楸1号,表明‘008-1’的耐盐性较‘苏楸1号’更强。(2)喷施外源ABA使得盐胁迫下‘008-1’楸树的苗高显著增加、新叶提前萌发,表明外源ABA在一定程度上能够缓解盐胁迫对楸树生长的影响;喷施外源ABA降低了盐胁迫下‘008-1’楸树幼苗叶片的REC,提高了Chl、RWC、SS、SP、Pro、SOD、过氧化物酶(POD)以及过氧化氢酶(CAT)活性,促进了内源激素生长素(IAA)、脱落酸(ABA)、赤霉素(GA3)以及玉米素核苷(ZR)的积累。研究表明,楸树品种‘008-1’的耐盐性更强;外源喷施适宜浓度ABA能够缓解盐胁迫对楸树幼苗生长的影响,降低幼苗叶片细胞膜透性,促进幼苗渗透调节物质的积累,增强渗透调节能力,并提高盐胁迫下幼苗的抗氧化酶活性,促进植物对内源激素含量的调节,从而提高楸树的耐盐性,且以25 mg/L ABA处理的效果最好。     

冠菌素和茉莉酸甲酯诱导小麦幼苗低温抗性的研究

以小麦品种豫麦18为试验材料,研究了冠菌素和茉莉酸甲酯(MeJA)对小麦低温抗性的诱导作用.结果表明,冠菌素和MeJA处理可以显著提高低温胁迫下小麦幼苗细胞内SOD、POD和CAT等抗氧化酶的活性,增加可溶性蛋白的含量,降低相对电导率和MDA含量,从而维持细胞质膜的完整性,增强小麦植株抵抗低温胁迫的能力.冠菌素和MeJA在抗低温胁迫上具有相似的作用,1μmol/L的冠菌素和100μmol/L MeJA的诱导效果较好.     

硝酸镧提高黑麦草种子活力和幼苗生物量的生理效应

研究了不同浓度硝酸镧对黑麦草种子萌发和幼苗生长的影响及其生理生化变化。结果表明,低浓度硝酸镧（1000mg·L^-1）处理能够提高黑麦草种子的活力和萌发种子的淀粉酶、蛋白酶和脂肪酶活性及IAA、GA和CTK含量;促进幼苗光合速率提高和干物质积累,这可能与硝酸镧提高幼苗叶片叶绿素含量和叶绿体希尔反应活力,促进光合电子传递和磷酸化反应及激活Rubisco羧化活性、PEP羧化酶活性有密切关系,其中以30mg．L^-1浓度处理的效果最佳;高浓度硝酸镧（70-100mg·L-1）处理则降低种子活力和抑制幼苗生长。而10-100mg．L-1硝酸镧对种子的萌发率、ABA含量和Rubisco的加氧活性影响不大。由此可见,低浓度硝酸镧可通过参与萌发和光合过程的调控提高黑麦草种子的活力,促进幼苗生长。     

土壤干旱条件下氮素营养对玉米内源激素含量影响

在田间持水量分别保持于35％、55％和75％±5％的土壤水分条件下,利用盆栽实验研究了土壤干旱和氮素营养对玉米内源激素和气孔导度的影响．结果表明,土壤干旱下氮素营养明显降低了玉米根系木质部汁液ABA浓度,而正常供水下施氮处理间则无显著差异(施氮处理仍较低),同时测定的叶片ABA浓度则呈相反的变化趋势,表现为干旱下施氮处理要高于不施氮处理;施氮处理木质部汁液中ZRs浓度应低于相应的不施氮处理,在调控气孔行为方面并未表现拮抗ABA作用;3种土壤水分条件下,施氮玉米叶片的气孔导度均高于不施氮处理,与木质部汁液ABA浓度呈负相关,说明施氮处理较低的根源ABA浓度是导致其气孔导度较大的主要原因．     

Fulvic Acid,Brassinolide, and Uniconazole Mediated Regulation of Morphological and Physiological Traits in Maize Seedlings Under Water Stress

Water stress is one of the most important factors limiting sustainable crop production. Therefore, the effects of the plant growth regulators (PGRs) fulvic acid (FA), brassinolide (BR), and uniconazole (Uni) on seedling growth and physiology of two maize (Zea mays L.) varieties were evaluated under???0.7 MPa water stress induced by polyethylene glycol-6000. Under drought stress, the PGRs promoted seedling growth, altered the root-to-shoot ratio, and significantly increased root biomass, length, surface area, diameter, and volume. In addition, depending on the PGR, net photosynthesis rate, SPAD value (indicating chlorophyll content), and water use efficiency increased significantly, under drought stress, whereas transpiration rate decreased. The PGRs also significantly increased antioxidant enzyme activities and significantly decreased malondialdehyde accumulation in leaves and roots under drought stress. Zhengdan958 showed greater variation in physiological responses and stronger drought resistance than Xundan20. In alleviating drought stress in maize seedlings, FA had the greatest effects on shoot growth and leaf physiology; Uni exerted its effects by regulating root structure, and BR effects were intermediate. Under drought stress, the three PGRs increased maize seedling growth, which reduced drought stress-induced damage and improved plant ability to resist the adversity. Based on a comprehensive analysis of physiological indices of drought resistance, Uni is recommended as the best PGR to improve maize seedlings resistance to drought.

     

外源脱落酸对干旱胁迫下滇润楠幼苗生长及生理特性的影响

以滇润楠一年生实生苗为试验材料,研究在良好水分条件(土壤含水量为70%～75%田间持水量)、轻度干旱胁迫及重度干旱胁迫处理下(50%～55%和30%～35%田间持水量)进行外源脱落酸(ABA)喷施对其生长及生理特性的影响。结果表明: 干旱胁迫使得滇润楠幼苗叶片的相对含水量、株高和生物量显著下降,净光合速率及叶绿素荧光参数(PSⅡ最大光化学效率,F_v/F_m)有不同程度的下降,而根冠比、膜脂过氧化产物丙二醛(MDA)含量显著增加。外源ABA的喷施可提高干旱胁迫下滇润楠幼苗的适应性,尤其是重度干旱下,外源ABA显著提高了叶片相对含水量21.0%,同时增加了植株株高和生物量的累积,提高了根冠比,为良好水分条件的2.1倍;减少了干旱下膜脂过氧化产物MDA的累积,提高了抗氧化酶过氧化氢酶、超氧化物岐化酶的活性,显著增加了脯氨酸的含量,为良好水分条件的7.7倍。外源ABA的喷施显著缓解了干旱胁迫对植株光合器官的不利影响,减少干旱引起的叶片净光合速率及气孔导度的下降,并且减轻了PSⅡ受到干旱的伤害程度,重度干旱下喷施ABA的植株的F_v/F_m显著高于未喷施ABA的植株。外源ABA的喷施可以减轻干旱对滇润楠植株的伤害,提高其抗旱性。     

Biochar Application Improves the Drought Tolerance in Maize Seedlings

Application of biochar to agricultural soils is mostly used to improve soil fertility. Experimental treatments were comprised of two factors: i) drought at two level, i.e., 80% and 40% water holding capacity (WHC) which was maintained on gravimetric basis ii) three levels of biochar i.e., control, 2 t ha^-1 and 4 t ha^-1 added to soil. Experimentation was done to examine potential of biochar application to enhance the growth attributes, water relations, photosynthetic pigments and antioxidants activities in maize (Zea mays L.) seedlings. Results of study revealed that biochar application increased the growth qualities (total seedlings biomass, dry weight of shoot and root, shoot length and root length). In addition; contents of photosynthetic pigments (chlorophyll a, b, a + b and a/b), water relation (relative water contents, turgor potential, osmotic potential and water potential) were improved significantly due to addition of biochar. Addition of 4 t ha^-1 biochar led to significant rise activity of enzymatic antioxidant catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) in leaf of maize seedling sunder drought as well as well watered circumstances. However, biochar applied at the rate 4 t ha^-1 improved the all the physiological and biochemical attributes in maize seedlings under drought. From the results it was concluded that biochar application is an efficient way to alleviate adverse effect of drought stress on maize. In drought prone areas, long term impacts of biochar on production of maize and properties of soil could be recommended as upcoming shove.     

Overexpression of Arabidopsis Molybdenum Cofactor Sulfurase Gene Confers Drought Tolerance in Maize (Zea mays L.)

Abscisic acid (ABA) is a key component of the signaling system that integrates plant adaptive responses to abiotic stress. Overexpression of Arabidopsis molybdenum cofactor sulfurase gene (LOS5) in maize markedly enhanced the expression of ZmAO and aldehyde oxidase (AO) activity, leading to ABA accumulation and increased drought tolerance. Transgenic maize (Zea mays L.) exhibited the expected reductions in stomatal aperture, which led to decreased water loss and maintenance of higher relative water content (RWC) and leaf water potential. Also, transgenic maize subjected to drought treatment exhibited lower leaf wilting, electrolyte leakage, malondialdehyde (MDA) and H₂O₂ content, and higher activities of antioxidative enzymes and proline content compared to wild-type (WT) maize. Moreover, overexpression of LOS5 enhanced the expression of stress-regulated genes such as Rad 17, NCED1, CAT1, and ZmP5CS1 under drought stress conditions, and increased root system development and biomass yield after re-watering. The increased drought tolerance in transgenic plants was associated with ABA accumulation via activated AO and expression of stress-related gene via ABA induction, which sequentially induced a set of favorable stress-related physiological and biochemical responses.     

Identification of QTL for drought responses in maize and their use in testing causal relationships between traits

A difficulty in identifying traits that help crop plants maintaintheir yield under droughted conditions is distinguishing betweenthose traits that contribute to yield stability under droughtand traits that do not affect yield. With the development ofmolecular markers for many crops it is now possible to identifymajor quantitative trait loci (QTL) regulating specific droughtresponses. By comparing the coincidence of such QTL for specifictraits it is possible to test much more precisely than beforewhether a particular constitutive or adaptive response to droughtstress is likely to be of significance in improving droughtresistance. We have used this approach to identify QTL for ABAcontent and other traits likely to be important in determiningdrought response in maize. Eighty-four RFLP markers were mapped in an F2 population of81 plants from a cross between parents, Polj17 (drought resistant)and F-2 (drought sensitive), that differ markedly in many constitutiveand adaptive responses to drought stress. In a soil glasshouseexperiment, from which water was withheld for 3 weeks afteranthesis, flowering time, stomatal conductance, tissue ABA contents,leaf water relations parameters and fluorescence characteristics,root pulling force, and nodal root number were measured. Theminimum number and location of genes having major effects onthe traits were determined and possible causal relationshipsamongst them tested. Comparing the coincidence of QTL for ABAcontent and stomatal conductance showed that xylem ABA contentwas more likely to have had a regulatory effect on the stomatalconductance of those plants than the whole leaf ABA content.However, both xylem and leaf ABA contents were significantlyassociated with root characteristics, suggesting that the rootingbehaviour (either constitutive or adaptive) was important inregulating stress responses, particularly in determining xylemABA contents. We also found that Fm (a measure of the activityof photosynthetic reaction centres) was positively associatedwith chlorophyll concentration per unit area. Different methodsfor comparing QTL are presented and discussed. Key words: Quantitative trait loci (QTL), ABA content, rooting behaviour, fluorescence characteristics, drought responses, maize     

水分胁迫对春播玉米苗期生长及其生理生化特性的影响

采用盆栽试验,以‘蠡玉18'玉米单交种为供试材料,设置充分供水(CK)、轻度水分胁迫(LS)、中度水分胁迫(MS)和重度水分胁迫(SS)4个水分处理水平,研究了水分胁迫对春播玉米苗期保护酶活性和生长的影响,以探讨土壤水分胁迫对玉米苗期生长发育及其生理过程的影响机制.结果表明:(1)随着水分胁迫程度的加剧,玉米幼苗的生物量显著下降,根冠比、根系活力和脯氨酸含量增加,且水分胁迫对玉米幼苗地上部生物量的抑制作用更大;可溶性蛋白含量差异不明显,MDA含量波动变化.(2)随着水分胁迫时间的延长,根冠比、根系活力和植株脯氨酸含量先升高后降低,可溶性蛋白含量呈先下降后升高的趋势;玉米幼苗叶片和根系MDA积累波动变化,而叶片MDA含量始终高于根系.(3)在水分胁迫初期,玉米叶片中CAT活性较SOD、POD响应更敏感;玉米苗期根系在中度水分胁迫下主要依赖CAT来降低氧化危害,而在重度水分胁迫下前期主要依赖CAT、后期通过CAT和POD的共同作用来降低氧化伤害;水分胁迫条件下,叶片和根系POD同步降低氧化伤害,而SOD和CAT在叶片和根系间存在互补作用.研究表明,在不同程度的水分胁迫条件下,玉米幼苗的生长受到一定程度的抑制,但其能够通过调节自身的保护酶活性和渗透调节物质含量来减轻干旱伤害,维持植株的正常生理代谢功能.     

Drought-induced changes in xylem pH, ionic composition, and ABA concentration act as early signals in field-grown maize (Zea mays L.).

Early signals potentially regulating leaf growth and stomatal aperture in field-grown maize (Zea mays L.) subjected to drought were investigated. Plants grown in a field lysimeter on two soil types were subjected to progressive drought during vegetative growth. Leaf ABA content, water status, extension rate, conductance, photosynthesis, nitrogen content, and xylem sap composition were measured daily. Maize responded similarly to progressive drought on both soil types. Effects on loam were less pronounced than on sand. Relative to fully-watered controls, xylem pH increased by about 0.2 units one day after withholding irrigation (DAWI) and conductivity decreased by about 0.25 mS cm(-1) 1-3 DAWI. Xylem nitrate, ammonium, and phosphate concentrations decreased by about 50% at 1-5 DAWI and potassium concentration decreased by about 50% at 7-8 DAWI. Xylem ABA concentration consistently increased by 45-70 pmol ml(-1) at 7 DAWI. Leaf extension rate decreased 5 DAWI, after the changes in xylem chemical composition had occurred. Leaf nitrogen significantly decreased 8-16 DAWI in droughted plants. Midday leaf water potential and photosynthesis were significantly decreased in droughted plants late in the drying period. Xylem nitrate concentration was the only ionic xylem sap component significantly correlated to increasing soil moisture deficit and decreasing leaf nitrogen concentration. Predawn leaf ABA content in droughted plants increased by 100-200 ng g(-1) dry weight at 7 DAWI coinciding with a decrease in stomatal conductance before any significant decrease in midday leaf water potential was observed. Based on the observed sequence, a chain of signal events is suggested eventually leading to stomatal closure and leaf surface reduction through interactive effects of reduced nitrogen supply and plant growth regulators under drought.     

Effects of S-Abscisic Acid (S-ABA) on Seed Germination,Seedling Growth,and Asr1 Gene Expression Under Drought Stress in Maize

The objective of this study was to evaluate the ability of the phytohormone S-abscisic acid (S-ABA) to protect maize seedlings grown under drought stress and to measure their increased drought tolerance. The maize hybrids ‘Zhengdan 958’ (ZD958; drought tolerant) and ‘Xundan 20’ (XD20; drought sensitive) were treated with nutrient solutions of different concentrations (1, 2, 4, 8, and 10 mg/kg) of S-ABA under polyethylene glycol (PEG, 15% w/v, MW 6000) simulated drought stress. Optimal concentrations of S-ABA were designed to be sprayed onto the leaves of seedlings, and their effect on endogenous ABA, malondialdehyde (MDA), osmotic substances, antioxidant enzyme activities, and Asr1 gene expression in seedlings were studied. Results indicated that, under drought stress, S-ABA treatment significantly improved maize seed germination rate (GR), germination energy (GE), and seedling biomass (p < 0.05). After spraying 4 mg/kg S-ABA onto leaves, the endogenous hormone ABA, osmotic substances, antioxidant enzyme activities, and expressive quantity of the Asr1 gene were extended and MDA content dropped significantly (p < 0.05). Moreover, ZD 958 endogenous ABA content, osmotic substances content, antioxidant enzyme activity and Asr1 gene expressive quantity were higher than that of XD 20 (p < 0.05). In conclusion, S-ABA treatment increased the content of endogenous ABA, induced an increase in antioxidant enzyme activity and Asr1 gene expression level, reduced the oxidative damage caused by drought to maize leaves, and improved the adaptability of maize seedlings to withstand drought stress. The promoting effect of S-ABA on the drought-tolerant variety ZD 958 was more obvious (p < 0.05). These results serve as a reference for the use of S-ABA in mitigating drought stress in maize.