甘蔗HTD2基因的表达特征及基因多态性分析  

Expression characteristic and gene diversity analysis of ScHTD2 in sugarcane

作　　者：李旭娟[1] 李纯佳[1] 吴转娣[1] 田春艳 胡鑫 丘立杭[2] 吴建明[2] 刘新龙[1] LI Xu-Juan;LI Chun-Jia;WU Zhuan-Di;TIAN Chun-Yan;HU Xin;QIU Li-Hang;WU Jian-Ming;LIU Xin-Long(Sugarcane Research Institute,Yunnan Academy of Agricultural Sciences/Yunnan Key Laboratory of Sugarcane Genetic Improvement,Kaiyuan 661699,Yunnan,China;Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences/Guangxi Key Laboratory of Sugarcane Ge-netic Improvement,Nanning 530007,Guangxi,China)

机构地区：[1]云南省农业科学院甘蔗研究所/云南省甘蔗遗传改良重点实验室,云南开远661699 [2]广西农业科学院甘蔗研究所/广西甘蔗遗传改良重点实验室,广西南宁530007

出　　处：《作物学报》2022年第7期1601-1613,共13页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31760412);国家重点研发计划项目(2019YFD1000500)资助。

摘　　要：分蘖是无性繁殖经济作物-甘蔗最重要的农艺性状之一,挖掘分蘖关键基因用于甘蔗理想株型调控是增加品种产量的重要途径。本研究使用实时荧光定量PCR技术对前期从甘蔗中获得的与水稻分蘖关键基因HTD2高度同源的ScHTD2基因开展表达特征分析,然后探讨其在甘蔗种质资源群体中的基因多态性情况,筛选与分蘖性状相关的变异位点。结果显示,该基因表达具有组织特异性,在叶中表达最高;腋芽萌动发育过程中,在休眠芽中表达量最高,随着蔗芽萌动,开始显著下调表达,负调控蔗芽的萌动发育;植物激动素、生长素和独脚金内酯都能显著诱导该基因在萌动蔗芽和蔗苗分蘖芽中的表达,结合激素处理的表型变化特征,预示生长素和独脚金内酯诱导该基因的高表达会抑制萌动蔗芽的继续发育和延迟蔗苗的分蘖,但植物激动素诱导的高表达并没有这种抑制效应。对从26份甘蔗种质资源中获得的520条HTD2基因组DNA克隆序列开展基因多态性分析表明,在基因组结构上,该基因具有2个外显子和1个内含子,其中内含子区域变异最为丰富。从群体基因多态性看,原始种亲本群体在外显子1和2区域表现出较高的核苷酸多样性,而主栽品种群体在内含子区域表现出较高的核苷酸多样性。从编码区单倍型多样性来看,原始种亲本群体间单倍型多样性最为丰富,其次为主栽品种群体。基因选择性测验中,原始种亲本群体受正向选择,选择压力较大,基因进化速度快,而骨干亲本群体和主栽品种群体受负向选择,向纯化方向发展。编码区单倍型演化分析表明,Hap3和Hap4处于单倍型演化的辐射中心,属于较为原始的类型。基因编码区变异位点与分蘖率相关性检测揭示该基因有23个SNP位点和5个InDel位点不同变异类型剂量与甘蔗种质资源分蘖率呈显著相关,变异类型剂量效应将是未来甘蔗分子辅助育种�Tillering is one of the most important agronomic traits for sugarcane which is a vegetatively propagated economic crop.Mining these genes related to tillering trait and utilizing them form an ideal architecture are important to effectively increase cane yield of sugarcane varieties.In this study,qRT-PCR technology was used to explore the expression characteristics of a homologue of HTD2 related to rice tillering,which was named ScHTD2 previously obtained from sugarcane.The polymorphism of ScHTD2 gene in sugarcane germplasm resource population was analyzed,and the correlation between variation sites and tillering trait were also detected.The results showed that relative expression of this gene was tissue specific and highest in leaves.During the germi-nation and development of axillary,the relative expression was the highest in the dormant buds.With the germination of sugar buds,the relative expression level first was significantly down-regulated,and the germination and development of sugar buds were negatively regulated.Treatments of phytokinin,auxin and strigolactone can significantly induce its expression in germinat-ing axillary buds and tiller buds of seedling.By combining with the phenotypic changes after hormone treatment,the high expres-sion of this gene induced auxin and strigolactone could inhibit the continued development of germinating axillary buds and delay the occurrence of tillers,but this inhibitory effect did not occur in the high expression of this gene induced by phytokines.Gene polymorphism analysis on 520 cloned sequences of HTD2 genomic DNA from 26 sugarcane germplasm resources showed that the genome sequence structure of this gene contained two exons and one intron,and the variation was the most abundant in the intron region,followed by the exon 1 region.Much higher nucleotide diversity in intron region was detected in main sugarcane variety population,while the origin species parent population had the higher nucleotide diversity in exon 1 and 2 regions.In terms of haplotype diversity in th

关 键 词：甘蔗 HTD2 基因表达 基因多态性 变异位点 

分 类 号：S566.1[农业科学—作物学]