混合盐碱胁迫对紫花苜蓿幼苗生理和基因表达的影响  

Effects of Mixed Saline-Alkali Stress on Physiology and Gene Expression of Alfalfa Seedlings

作　　者：朱晨晨 史昆 何沁坤 郑雨琴 苑峰 刘亚玲 王赞[1] ZHU Chen-chen;SHI Kun;HE Qin-kun;ZHENG Yu-qin;YUAN Feng;LIU Ya-ling;WANG Zan(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;Inner Mongolia Pratacultural Technology Innovation Center Co.,Ltd,Hohhot,Inner Mongolia 010070,China)

机构地区：[1]中国农业大学草业科学与技术学院,北京100193 [2]内蒙古草业技术创新中心有限公司,内蒙古呼和浩特010070

出　　处：《草地学报》2024年第4期1044-1054,共11页Acta Agrestia Sinica

基　　金：国家草业技术创新中心(筹)重大创新平台建设专项(CCPTZX2023B04);国家林业和草原种质资源库(2005DKA21003)资助。

摘　　要：本研究以‘ZN-1’和‘保定’苜蓿(Medicago sativa L.‘Baoding’)为试验材料,以浓度梯度为0 mmol·L^(-1),40 mmol·L^(-1)和80 mmol·L^(-1),pH值为9.3的混合盐碱溶液(NaCl∶Na_(2)SO_(4)∶NaHCO_(3)∶Na_(2)CO_(3)摩尔比为1∶1∶1∶1)进行胁迫处理,比较2个紫花苜蓿幼苗的生长指标、生理指标和基因表达(ROS清除、离子转运和光合调控3类基因)差异,以期为解析紫花苜蓿耐混合盐碱胁迫响应机制提供理论依据。结果表明,随着混合盐碱胁迫浓度的增加,2个紫花苜蓿的株高、干重、叶绿素含量、光合速率以及Fv/Fm等均出现明显的损伤(P<0.05)。其中,‘ZN-1’的耐混合盐碱性显著高于‘保定’苜蓿,主要表现为‘ZN-1’的株高和生物量更高、叶绿素含量和抗氧化酶的活性更高,净光合速率更强,脯氨酸和可溶性糖含量更高,叶片ROS积累量和地下部Na+积累更少,ROS清除、脯氨酸生物合成、Na+液泡区隔化以及叶绿素维持相关编码基因的表达水平更高。因此,脯氨酸生物合成、Na+液泡区隔化、叶绿素维持以及抗氧化酶可能在‘ZN-1’耐混合盐碱胁迫中发挥重要作用。In this study,two alfalfa(Medicago sativa L.)materials‘Baoding’and‘ZN-1’were treated with the mixed saline-alkali solution(NaCl∶Na_(2)SO_(4)∶NaHCO_(3)∶Na_(2)CO_(3)in 1∶1∶1∶1 ratio at pH 9.3)at the concentrations of 0 mmol·L^(-1),40 mmol·L^(-1)and 80 mmol·L^(-1),and compared for the tolerance.The morphology,physiology,and expression of the selected genes that are involved in ROS-scavenging,ion transport,and photosynthetic regulation were investigated at the alfalfa seedling stage,to look into the response to mixed saline-alkali stress.The results showed that with the increase of mixed saline-alkali concentration,significant(P<0.05)damage was observed in the plant height,dry weight,chlorophyll content,photosynthetic rate,and Fv/Fm,in both the alfalfa materials.Compared with‘Baoding’,‘ZN-1’demonstrated significantly higher saline-alkali tolerance,as evidenced by higher plant height,more biomass,more contents of chlorophyll content,proline,and soluble sugar,stronger antioxidant activity,promoted robust photosynthesis,and less accumulation of ROS in leaves and Na+in root.In‘ZN-1’,the significantly up-regulated genes were associated with the pathways of ROS scavenging,proline biosynthesis,Na+vacuolar compartmentalization,and chlorophyll maintenance.In summary,proline biosynthesis,Na+vacuolar compartmentalization,chlorophyll maintenance,and antioxidants may play an important role in the‘ZN-1’tolerance of mixed saline-alkali stress.

关 键 词：紫花苜蓿 混合盐碱胁迫 生理响应 基因表达 

分 类 号：S541.9[农业科学—作物学]