中苜一号紫花苜蓿幼苗对混合盐碱胁迫的响应  

Response of‘Zhongmu No.1’Alfalfa Seedlings to Mixed Saline-Alkali Stress

作　　者：朱晨晨 史昆 何沁坤 迪力穆拉提·阿卜杜外力 刘亚玲 王赞[1] ZHU Chenchen;SHI Kun;HE Qinkun;Dilmurat Abduwali;LIU Yaling;WANG Zan(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;Inner Mongolia Pratacultural Technology Innovation Center Co.,Ltd,Hohhot 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：《中国草地学报》2024年第8期1-9,共9页Chinese Journal of Grassland

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)。

摘　　要：本研究以中苜一号紫花苜蓿(Medicago sativa L.cv.Zhongmu No.1)为试验材料,分别进行浓度为0、40、80 mmol/L的混合盐碱胁迫(NaCl、Na_(2)SO_(4)、Na_(2)CO_(3)和NaHCO_(3)摩尔比为1∶1∶1∶1,pH值为9.3)处理,测定生长指标、生理指标及关键基因的表达水平,以期揭示其响应混合盐碱胁迫的机制。结果表明:随着混合盐碱胁迫程度的加剧,中苜一号紫花苜蓿幼苗的株高、光合速率、PSⅡ的有效量子产率和最大光化学量子产量均被显著抑制(P<0.05),过氧化氢、超氧阴离子和丙二醛积累量逐渐增多,过氧化物酶活性、脯氨酸和可溶性糖含量均显著增加(P<0.05);在80 mmol/L混合盐碱胁迫下,Na^(+)转运蛋白的编码基因MsSOS1、MsNHX1和MsHKT1的表达量均显著提高(P<0.05)。综合分析表明,中苜一号紫花苜蓿可能主要通过以下途径响应混合盐碱胁迫:(1)高表达MsSOS1、MsNHX1和MsHKT1等Na^(+)转运蛋白编码基因,促进Na^(+)外排、液泡区隔化及转移,避免因Na^(+)大量积累对植株造成离子毒害;(2)增强抗氧化酶活性,缓解由高pH值带来的氧化损伤。In this study,alfalfa(Medicago sativa cv.Zhongmu No.1)was used as experimental material under mixed saline-alkali stress at concentrations of 0,40,and 80 mmol/L(NaCl,Na_(2)SO_(4),Na_(2)CO_(3)and NaHCO_(3)molar ratios of 1∶1∶1∶1,pH 9.3).The growth indexes,physiological indexes and the expression levels of key genes of the seedlings were measured,which provided a theoretical basis for revealing the mechanism of response to mixed saline-alkali stress.The results showed that the plant height,photosynthetic rate,effective quantum yield of PSⅡphotochemistry and the maximum quantum efficiency of PSⅡphotochemistry(Fv/Fm)in‘Zhongmu No.1’alfalfa seedlings were significantly inhibited with the intensification of mixed saline-alkali stress(P<0.05).The accumulation of hydrogen peroxide,superoxide anion,and malondialdehyde gradually increased,while the activity of peroxidase,proline,and soluble sugar content all significantly increased(P<0.05).Under 80 mmol/L mixed saline-alkali stress,the expression levels of Na^(+)transporter encoding genes MsSOS1,MsNHX1,and MsHKT1 were significantly induced(P<0.05).In summary,‘Zhongmu No.1’alfalfa may mainly respond to mixed saline-alkali stress through the following pathways:(1)high expression of Na^(+)transporter genes such as MsSOS1,MsNHX1,and MsHKT1,promoting Na^(+)efflux,vacuolar segregation and transfer,and avoiding ion toxicity to plants caused by excessive accumulation of Na^(+);(2)enhance antioxidase activity and alleviate oxidative damage caused by high pH value.

关 键 词：中苜一号紫花苜蓿 混合盐碱胁迫 生理特性 基因表达 

分 类 号：S541.9[农业科学—作物学]