外源油菜素内酯缓解谷子穗分化期干旱胁迫的机理研究  

Mechanism of Exogenous Brassinolide in Alleviating Drought StressInjury at Panicle Differentiation Stage in Foxtail Millet

作　　者：杜杰 冯宇 夏清 智慧 王文霞 Du Jie;Feng Yu;Xia Qing;Zhi Hui;Wang Wenxia(Department of Life Sciences,Lüliang University,Lüliang 033000,Shanxi,China)

机构地区：[1]吕梁学院生命科学系,山西吕梁033000

出　　处：《作物杂志》2024年第4期144-151,共8页Crops

基　　金：山西省青年科学基金(202203021222320);山西省高等学校科技创新项目(2023L377);吕梁市高层次科技人才计划项目(2023RC20)。

摘　　要：为探究油菜素内酯对干旱胁迫下谷子穗分化期光合特性、抗氧化系统及氮代谢的调控作用,以优质谷子晋谷21号为供试材料,采用盆栽试验,设置正常对照(CK)、喷施清水后干旱(DS)和喷施油菜素内酯后干旱(BR)3个处理,待植株生长至穗分化期各处理组叶面分别喷施清水和0.1μmol/L的油菜素内酯,干旱结束后对所有处理的谷子光合作用参数、过氧化氢(H_(2)O_(2))、丙二醛(MDA)含量、渗透调节物质、抗氧化酶活性、氮代谢关键酶活性和产量及其构成进行测定与分析。结果表明,干旱胁迫极大地阻碍了穗分化期谷子生长发育,外源油菜素内酯的应用明显缓解了旱害对谷子的影响,产量显著提高17.29%,穗粒重增加8.62%,空秕率下降18.46%,谷子净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、叶绿素含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、可溶性糖、游离脯氨酸、硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)和谷氨酸脱氢酶(GDH)活性等指标不同程度提高,并显著降低H2O2和MDA含量。因此,喷施0.1μmol/L的油菜素内酯通过提高Pn、叶绿素值和渗透调节物质含量、增加抗氧化酶和氮代谢关键酶活性、降低活性氧和MDA含量,促进植株体内活性氧自由基清除、维持植株碳氮代谢平衡等来缓解穗分化期干旱胁迫对谷子生长发育及产量的降低。A pot experiment was conducted to investigate the regulatory effects of brassinolide on photosynthesis,antioxidant systems,and nitrogen metabolism in the high-quality foxtail millet variety,Jingu 21,under drought stress during panicle differentiation.Three treatment groups were established:a normal control(CK),a drought stress after water spraying(DS),and a drought stress after brassinolide spraying(BR).Upon reachingpanicledifferentiation,the treatment groups were separately sprayed with water and 0.1μmol/L brassinolide ontheleafsurface.After the cessation of drought stress,parameters including photosynthesis indices,hydrogen peroxide(H2O2),malondialdehyde(MDA)contents,osmotic regulators,antioxidant enzyme activity,nitrogen metabolismkey enzyme activity,yield,and its components were measured and analyzed for all treatments.The resultsshowed that drought stress significantly impeded the growth and development of foxtail millet during the panicledifferentiation stage,but the application of exogenous brassinolide could mitigate these adverse effects.Yieldandgrain weight per panicle were increased by 17.29%and 8.62%,respectively,while the empty seed ratewasdecreased by 18.46%.Several parameters like net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),chlorophyll content,superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)activities,soluble sugar,free proline,nitrate reductase(NR),glutamine synthase(GS),glutamate synthase(GOGAT),and glutamate dehydrogenase(GDH)activities increased to varying degrees.H2O2 and MDAcontentswere significantly reduced.Consequently,spraying 0.1μmol/L brassinolide could alleviate the reductionoffoxtail millet growth and yield under drought stress during panicle differentiation period by increasingphotosynthesis,chlorophyll content,osmotic regulators,antioxidant enzymes,nitrogen metabolismenzymes,andreducing reactive oxygen species and MDA content,facilitating reactive oxygen radicals scavenging,andmaintaining the balance of carbon and nitrogen metabolism in the pl

关 键 词：谷子 干旱胁迫 油菜素内酯 产量 氮代谢 

分 类 号：S515[农业科学—作物学]