OsSAUR55通过GA途径调控水稻株型  

OsSAUR55 Regulates Rice Plant Type Through GA Pathway

作　　者：浦娜 高巧丽 王慧[1] 刘金朝 陈嘉玲 罗增铜 肖武名[1] 陈淳[1] PU Na;GAO Qiaoli;WANG Hui;LIU Jinzhao;CHEN Jialing;LUO Zengtong;XIAO Wuming;CHEN Chun(National Engineering Research Center of Plant Space Breeding,South China Agricultural University,Guangzhou 510642,China;Guangzhou Academy of Agricultural Sciences,Guangzhou 510338,China)

机构地区：[1]华南农业大学国家植物航天育种工程技术研究中心,广东广州510642 [2]广州市农业科学研究院,广东广州510338

出　　处：《华北农学报》2024年第2期106-115,共10页Acta Agriculturae Boreali-Sinica

基　　金：岭南现代农业科学与技术广东省实验室河源分中心专项(DT20220012);广东省科技计划项目(2023B0202010003);广东省级乡村振兴战略专项资金种业振兴项目(2022-NPY-00-016)。

摘　　要：以Francis背景下通过CRISPR/Cas9技术获得的敲除突变体ossaur55-1、ossaur55-2为对象,研究其是否影响水稻株型、叶色、单株穗质量、结实率等农艺性状的变化,探究基因OsSAUR55是否通过参与GA途径调控水稻株型,为相关激素途径调控水稻株型提供理论依据。调查野生型(WT)与敲除突变体成株期的主要农艺性状,包括株高、穗长、单株穗质量、十粒长、十粒宽、剑叶长、剑叶宽等;利用叶绿素计和光合速率测定仪测定野生型和突变体齐穗期剑叶的叶绿素含量和净光合速率;通过实时荧光定量PCR技术(qPCR)测定基因OsSAUR55在水稻种子萌发的不同时间点和不同组织中的表达情况;通过原核表达法观察蛋白OsSAUR55的亚细胞定位情况;采用液相色谱-串联质谱法(LC-MS/MS)测定野生型和突变体的内源激素(GA和IAA)含量;进一步分析GA途径相关基因的表达情况。结果显示,在成株期,突变体ossaur55-1和ossaur55-2都有显著的表型变化,其中突变体的株高比野生型明显变矮、叶色更绿、叶绿素含量增加、光合作用效率降低、结实率降低、千粒质量降低、单株穗质量降低;定量结果显示,OsSAUR55在胚芽中表达量最高,在剑叶中基本不表达;共聚焦结果显示,OsSAUR55可能定位于细胞膜和细胞核;激素检测结果表明,突变体内源激素GA4的含量显著降低;基因的表达量分析发现,突变体中GA合成途径中基因KAO、GA13ox1、GA20ox1、KO1的表达量显著高于野生型,GA代谢途径中GA2ox5、GA2ox8、GA2ox9的表达量也显著高于野生型。初步推测,敲除基因OsSAUR55导致内源GA4含量降低,可能通过GA途径调控水稻株型,进而影响水稻产量。Knockout mutants ossaur55-1 and ossaur55-2 obtained by CRISPR/Cas9 technology in Francis background were used as research objects to study whether they affect the changes of agronomic traits such as plant type,leaf color,ear weight per plant and seed setting rate of rice.To explore whether OsSAUR55 regulates rice plant type by participating in GA pathway,and to provide theoretical basis for regulating rice plant type by related hormone pathway.The main agronomic traits of wild type(WT)and knockout mutant in adult plant stage were examined,including plant height,ear length,ear weight per plant,ten grain length,ten grain width,blade length,and blade width.Chlorophyll content and net photosynthetic rate of wild type and mutant leaf were measured by chlorophyll meter and photosynthetic rate meter.Real-time Fluorescence Quantitative PCR(qPCR)was used to determine the expression of OsSAUR55 gene in different tissues and different time points of rice seed germination.The subcellular localization of OsSAUR55 protein was observed by prokaryotic expression method.The contents of endogenous hormones(GA and IAA)in wild type and mutant were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The expression of genes related to GA pathway was further analyzed.In the adult plant stage,mutant ossaur55-1 and ossaur55-2 showed significant phenotypic changes,in which the mutant was significantly shorter in plant height,greener in leaf color,increased in chlorophyll content,decreased in photosynthetic efficiency,decreased in seed setting rate,decreased in 1000-grain weight and decreased in panicle weight per plant than the wild type.The quantitative results showed that OsSAUR55 expression was the highest in the plumule,but not in the flag leaf.Confocal results showed that OsSAUR55 may be localized in cell membrane and nucleus.The results of hormone detection showed that the content of GA 4 was decreased significantly.Gene expression analysis showed that the expression levels of genes KAO,GA13ox1,GA20ox1 and KO1 in

关 键 词：水稻 OsSAUR55 株型 CRISPR/Cas9 GA 产量 

分 类 号：S511.03[农业科学—作物学] Q78[生物学—分子生物学]