茉莉酸甲酯(MeJA)缓解高温影响玉米雌穗分化的生理机制OA
Physiological mechanisms of methyl jasmonate(MeJA)alleviating the effects of heat stress on ear differentiation in maize
全球气候变暖导致黄淮海地区夏玉米生长季高温胁迫呈现早发、频发、重发趋势,严重制约夏玉米雌穗发育及产量形成.茉莉酸甲酯(MeJA)在缓解逆境胁迫及促进生殖器官发育方面具有较高生物活性,是应对作物非生物逆境的优良外源调节物质之一.本研究以玉米品种先玉 335 为材料,于雌穗分化关键生育时期(小喇叭口期,V9;大喇叭口期,V12)在模拟高温胁迫条件下设置外源MeJA喷施处理,系统分析喷施后雌穗形态、小花分化数量、受精结实特性、内源激素含量、抗氧化酶活性和丙二醛含量的变化,以期明确其对高温阻碍夏玉米雌穗分化及受精结实的缓解效应.结果表明,喷施外源MeJA显著增加夏玉米幼穗反式玉米素+反式玉米素核苷、水杨酸和茉莉酸的含量,降低脱落酸的含量;超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性增强,丙二醛含量降低;雌穗长度、直径和小花数量分别增加 5.54%～48.88%、12.34%～24.41%和 2.51%～25.51%,同时雌穗顶部未发育长度降低 10.26%～50.00%.此外,MeJA 显著提高了雌穗吐丝数和小花受精率,降低了籽粒败育率,最终穗粒数增加 48.36%～57.23%,籽粒产量增加 49.14%～66.79%.表明外源 MeJA 通过调控内源激素合成,提高抗氧化系统活性,有效缓解高温诱导的氧化损伤,减轻高温对幼穗分化的抑制作用并改善其受精结实能力,增强植株对高温胁迫的应对能力,最终降低高温胁迫导致的产量损失.本研究为夏玉米抗高温栽培技术研发及稳产性能提升提供了理论依据.
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.
刘昕萌;任昊;张继波;张吉旺;赵斌;任佰朝;刘鹏;王洪章
山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东省气候中心,山东 济南 250031山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018山东农业大学农学院/黄淮海区域玉米技术创新中心,山东 泰安 271018
高温胁迫MeJA雌穗分化激素产量
heat stressMeJAear differentiationhormonesyield
《作物学报》 2026 (5)
1561-1572,12
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).
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