基于转录组分析云南山茶内源激素对干旱胁迫及复水的响应  

Response of endogenous hormones in Camellia reticulata to drought stress and rehydration based on transcriptome analysis

作　　者：雍清青 李紫倩 屈燕[1] YONG Qing-qing;LI Zi-qian;QU Yan(College of Landscape and Horticulture,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学园林园艺学院,昆明650224

出　　处：《西南农业学报》2024年第5期913-924,共12页Southwest China Journal of Agricultural Sciences

基　　金：国家“十三五”重点研发计划项目(2019YFD1001005)。

摘　　要：【目的】探究干旱胁迫对云南山茶内源激素的影响及植物激素响应干旱胁迫的分子机制。【方法】以半年生野生云南山茶盆栽苗为试验材料,利用20%PEG-6000模拟重度干旱胁迫,对干旱胁迫0、24、72 h和复水48 h的云南山茶根系及叶片生长素(IAA)、玉米素核苷(ZR)、赤霉素(GA)和脱落酸(ABA)含量进行测定,同时对叶片进行转录组测序并筛选差异基因。【结果】干旱胁迫下云南山茶内源激素均受到影响,叶中IAA含量先上升再下降复水后又上升,根中IAA含量持续下降,复水后未恢复;叶中ZR含量变化趋势与IAA相同,根中ZR含量变化趋势与叶相反;叶中GA含量在胁迫及复水期间持续上升,根中GA含量在胁迫期间上升,复水后下降;叶中ABA含量变化趋势与IAA相似,根中ABA含量在胁迫期间持续上升,复水后又下降,与根中GA含量变化趋势相似。云南山茶转录组测序结果中共筛选到33 349个差异表达基因,在胁迫及复水期间均显著富集在植物激素转导、类苯丙酸生物合成、类胡萝卜素生物合成、卟啉和叶绿素代谢、光合作用等通路中;干旱胁迫诱导了激素信号转导通路中46个差异基因表达。通过加权基因共表达网络分析鉴定得到4个基因模块,将转录组与4种激素含量进行关联分析,筛选得到2个与激素响应高度相关的关键基因模块,分别包含2769和2502个基因,选择关键模块中前5%的基因进行共表达分析,获得6个关键基因(SDH1-1、PETC、VHA-A3、FtsH、chlD、TL17)和5个关键转录因子(IAA9、NAC、Trihelix、SWI/SNF、NF-YB)。【结论】干旱胁迫影响内源激素含量的变化及相关通路基因的表达,鉴定得到2个与干旱胁迫响应密切相关的共表达模块;发现SDH1-1、PETC、VHA-A3、FtsH、chlD、TL17等基因和IAA9、NAC、Trihelix、SWI/SNF、NF-YB等转录因子在云南山茶内源激素响应干旱胁迫过程中发挥了重要作用。[Objective]The paper aims to explore the effect of drought stress on endogenous hormones in Camellia reticulata and the molecular mechanism of plant hormone signal transduction pathway responding to drought stress.[Method]The pot seedlings of half-one-year-old wild C.reticulata were used as experimental materials,and 20%PEG-6000 was used to simulate severe drought stress.The contents of auxin(IAA),zeatin nucleoside(ZR),gibberellin(GA)and abscisic acid(ABA)in roots and leaves of C.reticulata at O,24,72 hours and 48 hours after rewater(re48 hours)under drought stress,and at the same time,the leaves were sequenced by transcriptome to screen differential genes.[Result]Under drought stress,the endogenous hormones in C.reticulata were all affected.The IAA content in leaves first increased and then decreased and then increased after rehydration,while the IAA content in roots continued to decrease and did not recover after rewa-ter.The change trend of ZR content in leaves was the same as IAA,while that in roots was opposite to that in leaves.GA content in leaves in-creased continuously during stress and rewater,while GA content in roots increased during stress and decreased after rewater.The change trend of ABA content in leaves was similar to IAA,and ABA content in roots continued to increase during stress,and then decreased after re-water,which was similar to the change trend of GA content in roots.A total of 33349 differentially expressed genes were screened from the transcriptome sequencing results of C.reticulata,which were significantly enriched in plant hormone transduction,phenylpropionic acid bio-synthesis,carotenoid biosynthesis,porphyrin and chlorophyll metabolism,photosynthesis and other pathways at four time points.Drought stress induced the expression of 46 differential genes in plant hormone signal transduction pathway.Four gene modules were identified by weighted gene co-expression network analysis(WGCNA),and the transcription group was corelated with the contents of the four hormones.Two key gene modules

关 键 词：云南山茶 干旱胁迫 内源激素 转录组学 WGCNA 

分 类 号：S685[农业科学—观赏园艺]