作物学报2026，Vol.52Issue(5)：1561-1572,12.DOI:10.3724/SP.J.1006.2026.53068
茉莉酸甲酯(MeJA)缓解高温影响玉米雌穗分化的生理机制
Physiological mechanisms of methyl jasmonate(MeJA)alleviating the effects of heat stress on ear differentiation in maize
摘要
Abstract
Global warming has increased the frequency and severity of heat stress during the maize growing season in the Huang-Huai-Hai Plain of China,which can markedly hinder young ear development and cause substantial yield losses in summer maize.Methyl jasmonate(MeJA)is a biologically active compound that can alleviate abiotic stress and promote reproductive development,and thus represents a promising exogenous regulator for improving crop stress responses.This study aimed to clar-ify the effects of MeJA on young ear differentiation,fertilization,and seed-setting traits during the floret differentiation stage un-der heat stress.The summer maize cultivar Xianyu 335 was used as the experimental material.Exogenous MeJA was applied by foliar spraying at two key stages of ear differentiation(V9,9th leaf stage;V12,12th leaf stage)under simulated heat-stress condi-tions.By quantifying endogenous hormones and antioxidant responses,we elucidated how MeJA regulates ear morphology,floret number,and fertilization and seed-setting characteristics under heat stress.Exogenous MeJA significantly increased the contents of trans-zeatin+trans-zeatin riboside,salicylic acid,and jasmonic acid in young ears while reducing abscisic acid content.Compared with the control,MeJA also increased superoxide dismutase,peroxidase,and catalase activities in young ears and re-duced malondialdehyde accumulation,thereby enhancing stress tolerance and mitigating heat stress-induced damage.Accordingly,MeJA increased young ear length,diameter,and floret number by 5.54%-48.88%,12.34%-24.41%,and 2.51%-25.51%,respec-tively,and reduced the length of the undeveloped ear portion by 10.26%-50.00%.In addition,MeJA significantly increased the number of exposed silks and the floret fertilization rate while decreasing the grain abortion rate,resulting in marked increases in kernels per ear(48.36%-57.23%)and grain yield(49.14%-66.79%).Overall,MeJA alleviated heat stress-induced inhibition of ear differentiation by modulating endogenous hormone status and activating the antioxidant system in young ears,thereby reduc-ing oxidative damage and improving fertilization and seed-setting capacity.These findings provide a theoretical basis for devel-oping heat stress-resilient cultivation practices and stabilizing summer maize yield.关键词
高温胁迫/MeJA/雌穗分化/激素/产量Key words
heat stress/MeJA/ear differentiation/hormones/yield引用本文复制引用
刘昕萌,任昊,张继波,张吉旺,赵斌,任佰朝,刘鹏,王洪章..茉莉酸甲酯(MeJA)缓解高温影响玉米雌穗分化的生理机制[J].作物学报,2026,52(5):1561-1572,12.基金项目
本研究由国家自然科学基金项目(32572449,32071959),山东省现代农业产业技术体系项目(SDAIT02-08)和山东省博士后创新项目(SDCX-ZG-202400099)资助.This study was supported by the National Natural Science Foundation of China(32572449,32071959),the Shandong Modern Agricultural Industry Technology System(SDAIT02-08),and the Postdoctoral Innovation Program of Shandong Province(SDCX-ZG-202400099). （32572449,32071959）
