本文主要研究内容
作者刘圆圆（2019）在《MTB消减茉莉酸信号的分子机制及其在番茄防御反应中的作用》一文中研究指出：番茄(Solanum lycopersicum)是一种重要的蔬菜作物,也是研究植物与病虫互作的经典模式植物。番茄在整个生长周期中都可能面临各种病虫的侵袭,给农业生产带来巨大的经济损失。茉莉酸(Jasmonicacid,JA)是植物应对机械伤害、咀嚼式昆虫和死体营养型病原菌侵害的重要植物激素。一般来说,植物通过核心转录因子MYC2启动并级联放大茉莉酸信号转导途径从而防御病虫侵害,但防御反应过度发生时则会抑制植物的生长和发育。因此,茉莉酸信号的适时消减对于植物完成正常生命周期至关重要。然而,目前人们对茉莉酸信号途径转录调控机理的认识主要集中在MYC2如何激活茉莉酸响应基因的表达方面,对于茉莉酸响应基因表达消减的机制认识尚浅。本论文以番茄为材料,研究茉莉酸信号的消减机制,不仅对阐明茉莉酸信号转导途径具有重要的科学意义,而且有助于建立一种依赖植物自身抗性的环境友好型的农业病虫害防治策略,以降低农业经济损失,因而具有较大的潜在应用价值。本研究发现番茄MYC2激活一类茉莉酸诱导的bHLH类型转录因子,MYC2-TARGETEDBHLH 1(MTB1),MTB2 和 MTB3,而 MTB1-3 抑制 MYC2 介导的茉莉酸响应基因的表达,从而形成负反馈调控通路,实现茉莉酸信号的消减。主要研究结果如下:1.转录共激活因子MED25和转录抑制因子JAZ7竞争性地结合MYC2。酵母双杂交和pull-down实验在体内和体外证明MYC2通过含有转录激活结构域的N-端与MED25互作,已有研究证明MYC2通过相同的区段与JAZ蛋白互作。酵母三杂交实验和pull-down实验证明MED25和JAZ7竞争性地与MYC2互作。暗示着JA信号转导途径的本质是MYC2通过结合不同的互作蛋白(转录共激活因子MED25或转录抑制因子JAZ)发挥转录激活或转录抑制功能,从而介导JA响应基因的激活或抑制。2.MYC2直接调控MYC2-likebHLH类型转录因子MTB1-3的表达。染色质免疫共沉淀实验和凝胶阻滞迁移实验表明MYC2直接结合MTB1-3的启动子区G-box基序。机械损伤可以诱导MTB1-3的表达,且这种诱导依赖于MYC2和MED25。3.通过构建MTB过表达(MTB1-OE)和低表达(MTB-RNAi)转基因材料,并检测这些材料中机械损伤和茉莉酸诱导的抗性基因表达,茉莉酸诱导的花青素积累和根长抑制,以及对昆虫和病原菌的抗性,发现MTB负向调控茉莉酸介导的响应。4.序列比对发现,与MYC2相比,MTB1-3的C-端(含bHLH结构域,负责形成同源、异源二聚体和结合DNA)比较保守,同源性高达92.75%;N-端(含转录调控结构域,负责与转录共激活因子MED25和转录共抑制因子JAZ互作)保守性较低,同源性仅为38.18%。MTB1可以与MYC2形成异源二聚体,并与MYC2竞争性结合相同的靶标基因启动子。MYC2能同时与MED25和JAZs互作,兼具转录激活功能和转录抑制功能,而MTB1-3只与JAZs互作,只具备转录抑制功能。MTB1-3 一方面通过与MYC2结合相同位点,降低MYC2对靶标基因启动子DNA的结合,从而抑制MYC2靶标基因的表达;另一方面,MTB1-3干扰MED25-MYC2的互作,影响MYC2-MED25功能复合体的形成,从而抑制MYC2的转录激活活性。5.由于MTB1-3负向调控茉莉酸介导的防御反应,我们利用CRISPR/Cas9基因编辑系统,对MTB1和MTB2基因进行编辑并获得功能缺失突变体mtb1-c和mtb1 mtb2-c。表型分析发现,mtb1-c和mtb1 mtb2-c提高了对昆虫的抗性而不影响生长发育,表明MTB1-3在番茄抗性机制研究和番茄育种中均有较大的应用价值。综上所述,本研究发现MTB1-3是茉莉酸信号转导途径中重要的负调控因子,通过抑制核心转录激活复合体MYC2-MED25的功能发挥消减茉莉酸信号的作用,作为“刹车”精细调节植物防卫反应强度,降低防卫反应过度对植物生长发育的抑制,从而更好地调控植物抗性反应和生长发育之间的平衡。本研究不仅深化了我们对植物激素茉莉酸介导的防御反应调控机制的理解,还构建了抗虫能力高而生长发育不受影响的番茄株系,为通过分子育种培育抗病新品种提供了重要的理论基础和研究材料。
Abstract
fan jia (Solanum lycopersicum)shi yi chong chong yao de shu cai zuo wu ,ye shi yan jiu zhi wu yu bing chong hu zuo de jing dian mo shi zhi wu 。fan jia zai zheng ge sheng chang zhou ji zhong dou ke neng mian lin ge chong bing chong de qin xi ,gei nong ye sheng chan dai lai ju da de jing ji sun shi 。mo li suan (Jasmonicacid,JA)shi zhi wu ying dui ji xie shang hai 、ju jiao shi kun chong he si ti ying yang xing bing yuan jun qin hai de chong yao zhi wu ji su 。yi ban lai shui ,zhi wu tong guo he xin zhuai lu yin zi MYC2qi dong bing ji lian fang da mo li suan xin hao zhuai dao tu jing cong er fang yu bing chong qin hai ,dan fang yu fan ying guo du fa sheng shi ze hui yi zhi zhi wu de sheng chang he fa yo 。yin ci ,mo li suan xin hao de kuo shi xiao jian dui yu zhi wu wan cheng zheng chang sheng ming zhou ji zhi guan chong yao 。ran er ,mu qian ren men dui mo li suan xin hao tu jing zhuai lu diao kong ji li de ren shi zhu yao ji zhong zai MYC2ru he ji huo mo li suan xiang ying ji yin de biao da fang mian ,dui yu mo li suan xiang ying ji yin biao da xiao jian de ji zhi ren shi shang jian 。ben lun wen yi fan jia wei cai liao ,yan jiu mo li suan xin hao de xiao jian ji zhi ,bu jin dui chan ming mo li suan xin hao zhuai dao tu jing ju you chong yao de ke xue yi yi ,er ju you zhu yu jian li yi chong yi lai zhi wu zi shen kang xing de huan jing you hao xing de nong ye bing chong hai fang zhi ce lve ,yi jiang di nong ye jing ji sun shi ,yin er ju you jiao da de qian zai ying yong jia zhi 。ben yan jiu fa xian fan jia MYC2ji huo yi lei mo li suan you dao de bHLHlei xing zhuai lu yin zi ,MYC2-TARGETEDBHLH 1(MTB1),MTB2 he MTB3,er MTB1-3 yi zhi MYC2 jie dao de mo li suan xiang ying ji yin de biao da ,cong er xing cheng fu fan kui diao kong tong lu ,shi xian mo li suan xin hao de xiao jian 。zhu yao yan jiu jie guo ru xia :1.zhuai lu gong ji huo yin zi MED25he zhuai lu yi zhi yin zi JAZ7jing zheng xing de jie ge MYC2。jiao mu shuang za jiao he pull-downshi yan zai ti nei he ti wai zheng ming MYC2tong guo han you zhuai lu ji huo jie gou yu de N-duan yu MED25hu zuo ,yi you yan jiu zheng ming MYC2tong guo xiang tong de ou duan yu JAZdan bai hu zuo 。jiao mu san za jiao shi yan he pull-downshi yan zheng ming MED25he JAZ7jing zheng xing de yu MYC2hu zuo 。an shi zhao JAxin hao zhuai dao tu jing de ben zhi shi MYC2tong guo jie ge bu tong de hu zuo dan bai (zhuai lu gong ji huo yin zi MED25huo zhuai lu yi zhi yin zi JAZ)fa hui zhuai lu ji huo huo zhuai lu yi zhi gong neng ,cong er jie dao JAxiang ying ji yin de ji huo huo yi zhi 。2.MYC2zhi jie diao kong MYC2-likebHLHlei xing zhuai lu yin zi MTB1-3de biao da 。ran se zhi mian yi gong chen dian shi yan he ning jiao zu zhi qian yi shi yan biao ming MYC2zhi jie jie ge MTB1-3de qi dong zi ou G-boxji xu 。ji xie sun shang ke yi you dao MTB1-3de biao da ,ju zhe chong you dao yi lai yu MYC2he MED25。3.tong guo gou jian MTBguo biao da (MTB1-OE)he di biao da (MTB-RNAi)zhuai ji yin cai liao ,bing jian ce zhe xie cai liao zhong ji xie sun shang he mo li suan you dao de kang xing ji yin biao da ,mo li suan you dao de hua qing su ji lei he gen chang yi zhi ,yi ji dui kun chong he bing yuan jun de kang xing ,fa xian MTBfu xiang diao kong mo li suan jie dao de xiang ying 。4.xu lie bi dui fa xian ,yu MYC2xiang bi ,MTB1-3de C-duan (han bHLHjie gou yu ,fu ze xing cheng tong yuan 、yi yuan er ju ti he jie ge DNA)bi jiao bao shou ,tong yuan xing gao da 92.75%;N-duan (han zhuai lu diao kong jie gou yu ,fu ze yu zhuai lu gong ji huo yin zi MED25he zhuai lu gong yi zhi yin zi JAZhu zuo )bao shou xing jiao di ,tong yuan xing jin wei 38.18%。MTB1ke yi yu MYC2xing cheng yi yuan er ju ti ,bing yu MYC2jing zheng xing jie ge xiang tong de ba biao ji yin qi dong zi 。MYC2neng tong shi yu MED25he JAZshu zuo ,jian ju zhuai lu ji huo gong neng he zhuai lu yi zhi gong neng ,er MTB1-3zhi yu JAZshu zuo ,zhi ju bei zhuai lu yi zhi gong neng 。MTB1-3 yi fang mian tong guo yu MYC2jie ge xiang tong wei dian ,jiang di MYC2dui ba biao ji yin qi dong zi DNAde jie ge ,cong er yi zhi MYC2ba biao ji yin de biao da ;ling yi fang mian ,MTB1-3gan rao MED25-MYC2de hu zuo ,ying xiang MYC2-MED25gong neng fu ge ti de xing cheng ,cong er yi zhi MYC2de zhuai lu ji huo huo xing 。5.you yu MTB1-3fu xiang diao kong mo li suan jie dao de fang yu fan ying ,wo men li yong CRISPR/Cas9ji yin bian ji ji tong ,dui MTB1he MTB2ji yin jin hang bian ji bing huo de gong neng que shi tu bian ti mtb1-che mtb1 mtb2-c。biao xing fen xi fa xian ,mtb1-che mtb1 mtb2-cdi gao le dui kun chong de kang xing er bu ying xiang sheng chang fa yo ,biao ming MTB1-3zai fan jia kang xing ji zhi yan jiu he fan jia yo chong zhong jun you jiao da de ying yong jia zhi 。zeng shang suo shu ,ben yan jiu fa xian MTB1-3shi mo li suan xin hao zhuai dao tu jing zhong chong yao de fu diao kong yin zi ,tong guo yi zhi he xin zhuai lu ji huo fu ge ti MYC2-MED25de gong neng fa hui xiao jian mo li suan xin hao de zuo yong ,zuo wei “cha che ”jing xi diao jie zhi wu fang wei fan ying jiang du ,jiang di fang wei fan ying guo du dui zhi wu sheng chang fa yo de yi zhi ,cong er geng hao de diao kong zhi wu kang xing fan ying he sheng chang fa yo zhi jian de ping heng 。ben yan jiu bu jin shen hua le wo men dui zhi wu ji su mo li suan jie dao de fang yu fan ying diao kong ji zhi de li jie ,hai gou jian le kang chong neng li gao er sheng chang fa yo bu shou ying xiang de fan jia zhu ji ,wei tong guo fen zi yo chong pei yo kang bing xin pin chong di gong le chong yao de li lun ji chu he yan jiu cai liao 。
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论文作者分别是来自浙江大学的刘圆圆，发表于刊物浙江大学2019-05-20论文，是一篇关于茉莉酸论文,抗性论文,转录调控论文,番茄论文,浙江大学2019-05-20论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自浙江大学2019-05-20论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：茉莉酸论文; 抗性论文; 转录调控论文; 番茄论文; 浙江大学2019-05-20论文;