综合生理学和转录组学揭示外源5-氨基乙酰丙酸调节‘德钦’紫花苜蓿耐热性的分子机制  

Integrated Physiological and Transcriptomic Analyses Reveals the Molecular Mechanism of Exogenous 5-aminolevulinic acid Regulating Heat Tolerance of Medicago sativa‘Deqin’

作　　者：杨姣 张鹤 赵雁[1] YANG Jiao;ZHANG He;ZHAO Yan(College of Horticulture and Landscape,Yunnan Agricultural University,Kunming,Yunnan Province 650201,China;Renshou County Planning and Natural Resources Bureau,Renshou,Sichuan Province 620500,China)

机构地区：[1]云南农业大学园林园艺学院,云南昆明650201 [2]仁寿县规划和自然资源局,四川仁寿620500

出　　处：《草地学报》2025年第4期1072-1084,共13页Acta Agrestia Sinica

基　　金：国家自然科学基金(31660683)资助。

摘　　要：为揭示外源5-氨基乙酰丙酸(ALA)调节‘德钦’紫花苜蓿(Medicago sativa‘Deqin’)的分子机制并为耐热育种提供理论基础。本研究先对处于42℃高温下长势一致35 d苗龄的苜蓿叶片用不同浓度ALA处理,筛选缓解高温胁迫的ALA最适浓度,再对其叶片进行常温无ALA(CK)、高温胁迫无ALA(Heat)、喷施20 mg·L-1ALA后常温培养或高温胁迫(ALA或HA)4种处理,测定生理指标,同时进行转录组测序和生物信息学分析。结果表明:20 mg·L-1ALA改善苜蓿苗期高温胁迫下各生理指标,其缓解效果最佳。对样本间的差异表达基因(DEGs)进行筛选,推测270个DEGs是外源ALA调控叶片响应高温胁迫的潜在相关基因。GO和KEGG富集以及DEGs共表达趋势结果表明,外源ALA主要参与介导苯丙烷类生物合成和植物激素信号转导两条通路的关键基因来响应高温胁迫。本研究为苜蓿耐热基因的挖掘提供依据,也为今后的分子育种奠定了理论基础。In order to reveal the molecular mechanism of exogenous 5-aminolevulinic acid(ALA)regulating Medicago sativa‘Deqin’and provide theoretical basis for heat-resistant breeding,alfalfa leaves with the same growth at 42℃for 35 days of seedling age were treated with different concentrations of ALA to screen the optimal concentration of ALA which could alleviate high temperature stress in this study.The leaves separately treated with room temperature without ALA(CK),high temperature stress without ALA(Heat),sprayed with 20 mg·L-1 ALA and cultured at room temperature or under high temperature stress(ALA or HA)were determined physiological indexes and performed transcriptomic sequencing and bioinformatics analysis.The results showed that 20 mg·L-1 ALA improved the physiological indexes of alfalfa under high temperature stress at seedling stage,and the relief effect was the best.The differentially expressed genes(DEGs)among the samples were screened,and 270 DEGs were estimated to be potential genes related to the regulation of exogenous ALA in leaf response to high temperature stress.The results of GO and KEGG enrichment and coexpression trends of DEGs indicated that exogenous ALA mainly involved in key genes mediating two pathways,phenylpropanoid biosynthesis and phytohormone signaling,in response to high-temperature stress.This study provided a basis for the mining of heat-resistant genes in alfalfa and laid a theoretical foundation for molecular breeding in the future.

关 键 词：紫花苜蓿 外源ALA 耐热性 苯丙烷类 植物激素 

分 类 号：Q945[生物学—植物学]