油菜素内酯调控谷子抗旱性的生理机制研究

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中图分类号：S515 文献标识码：A 文章编号：1671-8151（2025）04-0067-11

Abstract：[Objective]Droughtstress duringthebooting stageseverelyconstrains yieldformationinfoxtail milet.This studyaimedtoinvestigatetheefectsofexogenousbrassinosteroid（BR）aplicationonkeyphysiologicalandbiochemicalprocesestoelucidateitsroleinenancingdroughttolerance，providingatheoreticalbasis forBR-baseddroughtresistanceimprovement.[Method]Using thefoxtailmiletvariety‘Jingu21’asexperimentalmaterial，apotexperimentwasconducted withthr treatments：well-watered control（CK），，drought stress with water spray （DS），and drought stress with 0.1μmol/L BR application（DBR）.Theefectsofexogenous BRonyield parameters，photosyntheticcharacteristics（SPAD，Rubiscoactivityetpotosyntheticrate（Pn），stomatalconductance（Gs）），chlorophylfluorescence，osmolytes（soluble sugars，proline），antioxidantenzymes（superoxide dismutase（SOD），ascorbate peroxidase（APX），glutathione reductase（GR）），oxidative markers （hy-drogen peroxide （H2O2 ，malondialdehyde（MDA）），nitrogen metabolism enzymes（nitrate reductase（NR），glutamine syn-thetase（GS）），and endogenous hormones（endogenous gibberellin（ GA3） ，abscisic acid（ABA））in millet under droughtstresswere investigated.[Results]Compared toDS，DBR treatment significantlyimproved multiplephysiological ndicators：

photosynthetic parameters increased by 8.33%～26.15% with significant improvements in chlorophyll fluorescence parameters.Leaf soluble sugar and free proline content increased by 13.15% and 12.14% ，respectively；antioxidant enzymesactivities（SOD，APX，and GR） increased by 14.62%～31.63% ，while oxidative stress markers（ H2O2and MDA）reduced notably.DBR also significantly enhanced NR and GS activities，increased GA3 content by 14.98% and reduced ABA by 12.86% Ultimately，DBR significantly boosted yield by 16.10% per plant with improved panicle traits.[Conclusion]During the booting stage，exogenousbrassiosteroidapicationcaefecivelyalleviatethenegativeectsofdroughtstressonilltbyoptiiz ingphotosyntheticperformance，enhancingosmoticadjustment，activatingtheantioxidantdefensesystem，promotingnitrogen metabolism，andregulatingendogenoushormonebalancethroughmultiplephysiologicalpathways，therebyfacilitating yieldfor mation in millet.

Keywords：Foxtail millet，Drought，Booting stage，Brassinolide，Antioxidantsystem，Hormone regulation

谷子（SetariaitalicaL.）作为我国一种历史悠久的传统作物，不仅以其丰富的营养价值备受关注，更因其在干旱环境下的生长潜力而成为农业可持续发展中的重要资源[1。（剩余22923字）