小桐子JcGIGANTEA基因增强拟南芥盐敏感性的功能分析  

Functional Characterization of Jatropha curcas JcGIGANTEA Gene in Enhancing Salt Sensitivity in Arabidopsis thaliana

作　　者：陈鑫[1,2] 秦冬美 胥佳静 朱林慧 廖育焐 段兰娟 曾芷玉 黄赟凯 梁秀清 韩泽薇 李改萍 徐增富 倪军 CHEN Xin;QIN Dongmei;XU Jiajing;ZHU Linhui;LIAO Yuwu;DUAN Lanjuan;ZENG Zhiyu;HUANG Yunkai;LIANG Xiuqing;HAN Zewei;LI Gaiping;XU Zengfu;NI Jun(Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation,Key Laboratory of National Forestry and Grassland Administration on Cultivation of Fast-Growing Timber in Central South China,College of Forestry,Guangxi University,Nanning,530004;Guangxi Key Laboratory of Forest Ecology and Conservation,College of Forestry,Guangxi University,Nanning,530004)

机构地区：[1]广西大学林学院,中南速生材繁育国家林业和草原局重点实验室,广西高校亚热带人工林培育与利用重点实验室,南宁530004 [2]广西大学林学院,广西森林生态与保育重点实验室,南宁530004

出　　处：《基因组学与应用生物学》2024年第5期803-816,共14页Genomics and Applied Biology

基　　金：广西壮族自治区科技计划项目(2021GXNSFBA220062,桂科AD22035175,桂科JB22035001);国家自然科学基金项目(32001345)共同资助。

摘　　要：盐胁迫严重影响作物的生长发育,是限制作物产量提高的主要逆境之一。GIGANTEA(GI)是一种植物特异性蛋白,不仅参与调控植物的光周期、开花时间、蔗糖信号转导和淀粉积累等生理活动,还具有调控植物耐旱、耐寒和耐盐的抵御非生物逆境的功能。在木本油料作物小桐子(Jatropha curcas)中,GI蛋白的抗逆功能缺乏详细的研究。本研究的目的是探讨小桐子GI蛋白编码基因JcGI在调控盐胁迫方面的功能。本研究对小桐子JcGI进行生物信息学分析,构建JcGI基因超量表达载体,并通过农杆菌(Agrobacterium tumefacines)介导的浸花法获得超量表达JcGI基因的转基因拟南芥(Arabidopsis thaliana),以拟南芥野生型WT、拟南芥gi突变体和JcGI超量表达的拟南芥转基因株系为材料,研究了JcGI在调控植株耐盐性方面的作用。结果表明:(1)盐胁迫条件下,相比于野生型和gi突变体,JcGI超量表达株系的种子萌发率和根系生长的受抑制程度更显著,同时其叶绿素含量比野生型和gi突变体的更低;(2)盐胁迫处理后,JcGI超量表达株系的活性氧和过氧化氢含量显著增多,而可溶性糖含量和过氧化氢酶活性显著减少,gi突变体的则与之相反,同时JcGI超量表达株系的鲜重、干重和存活率相比于gi突变体的显著下降;(3)在含ABA的培养基中,相比于gi突变体和野生型,JcGI超量表达株系的根系受抑制程度更大,也表明超量表达株系对盐胁迫和ABA的响应高于gi突变体和野生型的响应。以上结果显示,JcGI超量表达株系的盐敏感性较高,而gi突变体具有更高的耐盐性,表明超量表达JcGI负调控拟南芥的耐盐性。Salt stress severely affects the plant growth and development,and frequently leads to decreased crop yield.GIGANTEA(GI)is a plant specific protein that not only regulates the physiological processes such as photoperiod,flowering time,sucrose signal transduction,and starch accumulation,but also plays a role in drought,cold,and salt tolerance.However,the detailed study on the stress tolerant function of the GI protein in Jatropha curcas is lacking.The aim of this study was to investigate the role of JcGI,a gene in J.curcas,in regulating salt stress.In this study,bioinformatical analysis of J.curcas JcGI was conducted,and a JcGI gene overex⁃pression vector was constructed.Transgenic Arabidopsis thaliana plants overexpressing JcGI were obtained through Agrobacterium tume⁃faciens⁃mediated floral⁃dip transformation.The wild type WT,gi mutant,and transgenic Arabidopsis thaliana lines with overexpression of JcGI were used to investigate the role of JcGI in regulating salt tolerance.The results showed that:(1)JcGI overexpressing lines ex⁃hibited a more pronounced inhibition of seed germination and root growth,and a significant decrease in chlorophyll content compared to the wild type and gi mutants under salt stress;(2)JcGI overexpressing lines showed increased levels of reactive oxygen species and hy⁃drogen peroxide,and decreased levels of soluble sugars and hydrogen peroxide enzyme activity,while the opposite was observed in gi mutants under salt stress,meanwhile,the fresh weight,dry weight and survival rate of JcGI overexpressing lines was significantly lower than that of gi mutants;(3)Root growth of JcGI overexpressing lines was significantly inhibited,in comparison with that of gi mutants and wild type in the ABA medium,it also showed that the response of overexpression lines to salt stress and ABA was higher than that of gi mutants and wild types.These results suggest that JcGI overexpressing lines are more salt⁃sensitive,while gi mutants have higher salt tolerance.Overall,the results demonstrate that

关 键 词：拟南芥 小桐子 JcGI基因 盐胁迫 

分 类 号：Q943.2[生物学—植物学]