中国生态农业学报（中英文）2025，Vol.33Issue(7)：1360-1370,11.DOI:10.12357/cjea.20240695
赤霉素浸种对紫花苜蓿幼苗盐胁迫的缓解作用及机制
The alleviating effect of gibberellin seed soaking on salt stress in alfalfa
摘要
Abstract
With the accelerating development and utilization of saline-alkali land resources in China,the cultivation area for alfalfa(Medicago sativa L.)in salinized soils has been continuously expanding.Enhancing salt tolerance during the seedling stage is crucial for successful establishment of alfalfa in challenging environments.Therefore,this study established three salt stress concentrations(0.3％,0.6％,and 0.9％)combined with three gibberellic acid(GA3)seed soaking concentrations(50,100,and 150 mg·L-1)to invest-igate the alleviating effects and mechanisms of exogenous GA3 on alfalfa under varying salt stress levels,while determining the op-timal GA3 concentrations corresponding to different salinity conditions.The results demonstrated that:Under 0.3％salt stress,maxim-um shoot length(21.13％increase)and root length(18.96％increase)were achieved at 150 mg·L-1 GA3,while 100 mg·L-1 GA3 signi-ficantly enhanced fresh weight(10.49％increase)and dry weight(10.56％increase)compared to the control.Under 0.6％salt stress,100 mg·L-1GA3 optimized shoot length(14.88％increase)and dry weight(8.84％increase),whereas 50 mg·L-1 GA3 produced the longest roots(18.82％increase).Under 0.9％salt stress,50 mg·L-1 GA3 significantly improved shoot length(15.70％increase),root length(10.75％increase),and dry weight(11.90％increase).Mechanistically,optimal GA3 concentrations alleviated salt stress by:1)Enhancing antioxidant enzyme activities(superoxide dismutase,peroxidase,catalase).2)Increasing endogenous phytohormone levels(auxin and salicylic acid).3)Reducing stress markers-malondialdehyde(MDA),abscisic acid(ABA),chloride ions(Cl-),and sodium ions(Na+).A distinct inverse proportional relationship was observed between optimal GA3 concentrations and salt stress intensity.Specifically,under low salinity(0.3％),GA3 concentrations of 100-150 mg·L-1 were most effective.For moderate salinity(0.6％),100 mg·L-1 GA3 proved optimal,while under high salinity(0.9％),a lower concentration of 50 mg·L-1 GA3 was sufficient to alleviate stress.This study confirmed that exogenous GA3 seed soaking effectively mitigates salt-induced phytotoxicity and promotes alfalfa seedling growth,with superior efficacy under low-to-moderate salt stress compared to severe stress conditions.These findings provide both a theoretical foundation and practical guidance for improving alfalfa cultivation efficiency in saline-alkali regions.关键词
紫花苜蓿/盐胁迫/赤霉素/浸种/生理生化Key words
alfalfa/salt stress/gibberellin acid(GA3)/seed soaking/physiology and biochemistry分类
农业科技引用本文复制引用
曲清华,王士超,谢锦,邓超艳,李瑶,韩立朴..赤霉素浸种对紫花苜蓿幼苗盐胁迫的缓解作用及机制[J].中国生态农业学报（中英文）,2025,33(7):1360-1370,11.基金项目
中国科学院前瞻战略科技先导专项(XDA0440401)资助 This study was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0440401). （XDA0440401）
