摘要
表观遗传与环境条件变化紧密相关,非生物胁迫影响植物表观遗传修饰状态,同时表观遗传也会影响植物的胁迫响应。本试验以蒺藜苜蓿为材料,系统地研究了其在盐、干旱、高温和低温胁迫下的形态、生理及表观遗传修饰动态变化,并结合相关性分析探究4种非生物胁迫下表观遗传修饰与形态和生理间的关联。结果表明:4种非生物胁迫对蒺藜苜蓿形态和生理造成了明显的抑制作用,表现为叶面积(除低温胁迫外)和叶鲜(干)重、茎鲜(干)重及地上鲜(干)重显著降低,相对含水量和总叶绿素含量显著降低,相对电导率、可溶性糖含量和总抗氧化能力显著升高(P<0.05);同时表观遗传参与了蒺藜苜蓿在逆境胁迫下的调控过程,但不同表观修饰间的调控方式存在差异,其中DNA甲基化含量均显著升高,乙酰化组蛋白含量均显著降低,而甲基化组蛋白含量仅在盐胁迫下显著升高,其余3种胁迫下显著降低,泛素化组蛋白含量在盐和低温胁迫下显著升高,高温胁迫下显著降低(P<0.05),干旱胁迫下变化不显著;相关性分析表明6-甲基腺嘌呤含量和乙酰化组蛋白含量与叶片形态指标(叶鲜重、叶干重和叶面积)呈显著正相关(除乙酰化组蛋白与叶面积不显著),而与逆境相关生理指标(相对电导率、可溶性糖和总抗氧化能力)呈显著负相关(除6-甲基腺嘌呤与相对电导率不显著)。该研究从表观遗传角度初步探究蒺藜苜蓿对不同非生物胁迫的适应特征,为豆科牧草抗逆表观分子育种提供重要的理论依据。
Epigenetics plays a pivotal role in the adaptation to fluctuating external environmental conditions.Abiotic stresses alter the epigenetic modification status of plants,which in turn regulate stress responses of plants.This study presented a comprehensive analysis of the morphological,physiological,and epigenetic dynamics in Medicago truncatula when subjected to salinity,drought,heat,and cold stresses.The interplay between epigenetic modifications with the morphological and physiological traits of Medicago truncatula under stress conditions were explored by correlation analysis.Results revealed that these abiotic stresses significantly inhibited the growth and physiological status of Medicago truncatula,in which reduction in leaf area(except under low temperature),the weight of leaves(dry),stems(dry)and above ground fresh(dry)was significantly reduced relative water content,and total chlorophyll content,and increase in relative electrical conductivity,soluble sugar,and total antioxidant capacity were observed(P<0.05).Meanwhile,epigenetics was involved in the regulatory processes of Medicago truncatula under stress conditions,though the regulatory mechanisms among various epigenetic modifications were different.Under all four stress conditions,DNA methylation levels significantly increased,while acetylated histone content reduced.Methylated histone content increased only under salt stress,with decreases under the other three stresses.Histones ubiquitinylation was risen under salt and low-temperature stress,whereas high-temperature stress reduced this content(P<0.05),also with no significant changes under drought stress.Correlation analysis further indicated a positive correlation between N-6-methyladenosine content and acetylated histones with leaf morphological indicators,such as leaf fresh weight,leaf dry weight,and leaf area,except in acetylated histones content with leaf area.Conversely,this two parameters were negatively correlated with physiological indicators such as relative electrical conductivity,soluble sugars,and total antioxidant capacity,except between N-6-methyladenosine content with relative electrical conductivity.This research provides preliminary evidence in adaptive characteristics of Medicago truncatula in response to various abiotic stresses from an epigenetic perspective and lays a foundational theoretical framework for the epigenetic molecular breeding of legume forage grasses to enhance stress tolerance.
作者
赵媛媛
徐成体
王伟
蒲小剑
魏希杰
张俊超
ZHAO Yuanyuan;XU Chengti;WANG Wei;PU Xiaojian;WEI Xijie;ZHANG Junchao(Academy of Animal Science and Veterinary/Key Laboratory of the Alpine Grassland Ecology in the Three Rivers Region,Ministry of Education,Qinghai University,Xining 810016,China;College of Grassland Resources/Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station,Southwest Minzu University,Chengdu 610041,China)
出处
《中国草地学报》
北大核心
2025年第5期89-101,共13页
Chinese Journal of Grassland
基金
青海大学青年科研基金(2023-QNY-6)
省部共建三江源生态与高原农牧业国家重点实验室自主课题(2024-ZZ-16)
三江源区高寒草地生态教育部重点实验室开放基金(2023-SJY-KF-03)
国家自然科学基金项目(32201452)。
