DNA拓扑异构酶基因PagTOP2b对银腺杨‘84K’生长发育的影响  

Effects of DNA topoisomerase PagTOP2b on growth and development of poplar ‘84K’

作　　者：郭雅琨 赵岩秋 杜娟 卢孟柱 GUO Yakun;ZHAO Yanqiu;DU Juan;LU Mengzhu(State Key Laboratory of Subtropical Silviculture,College of Forestry and Biotechnology,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China;College of Life Sciences,Zhejiang University,Hangzhou 310058,Zhejiang,China)

机构地区：[1]浙江农林大学林业与生物技术学院省部共建亚热带森林培育国家重点实验室,浙江杭州311300 [2]浙江大学生命科学学院,浙江杭州310058

出　　处：《浙江农林大学学报》2022年第6期1155-1162,共8页Journal of Zhejiang A&F University

基　　金：国家重点研发计划项目(2021YFD2200205,2021YFD2200700)。

摘　　要：【目的】DNA拓扑异构酶基因是一类能够改变DNA拓扑结构的酶,在基础生命活动如DNA复制、转录、有丝分裂等过程中发挥重要作用。研究DNA拓扑异构酶基因对杨树Populus生长发育的影响,能够进一步了解DNA拓扑异构酶基因在木本植物中的作用机制,评估其是否可作为林木分子育种的靶标。【方法】从银腺杨‘84K’ Populus alba×P. glandulosa ‘84K’(84K杨)中克隆得到DNA拓扑异构酶基因PagTOP2b,利用生物信息学方法对其进行序列分析、蛋白理化性质及结构分析。实时荧光定量PCR分析PagTOP2b在杨树不同组织中的表达水平。利用农杆菌Agrobacterium tumefaciens介导的叶盘转化法转化84K杨,得到PagTOP2b过表达转基因植株。通过表型及茎段切片分析过表达PagTOP2b基因对84K杨植株生长的影响。【结果】以84K杨cDNA为模板,克隆得到PagTOP2b基因全长序列,该基因蛋白质编码区(CDS)长度为4 449 bp,编码1 482个氨基酸,根据蛋白结构域分析属于ⅡA型DNA拓扑异构酶。PagTOP2b主要在杨树幼嫩组织中有较高的表达量。过量表达PagTOP2b基因会导致转基因植株高度、基部节间直径和木质部宽度显著增加。【结论】DNA拓扑异构酶作为一类参与基础生命活动的重要功能酶,在杨树中过量表达ⅡA型DNA拓扑异构酶基因PagTOP2b可促进植株的纵向及径向生长,增加植株生物量。图4表1参28。[Objective] DNA Topoisomerase, as a kind of enzyme that can change the topological structure of DNA, plays an important role in fundamental cellular activities such as DNA replication, transcription and mitosis, therefore, this study, with an investigtion into the effects of DNA topoisomerase genes on the growth and development of poplar, is aimed to lay a solid foundation for further understanding of the mechanism of DNA topoisomerase in woody plants and to evaluate whether it can be used as a target for molecular breeding.[Method] First, DNA topoisomerase gene PagTOP2b was cloned from poplar ‘84K’(Populus alba × P. glandulosa ‘ 84K’) before an analysis was conducted of its sequence and the protein physicochemical properties and structure with the employment of Bioinformatic method. Then, with an exploration of the expression levels in different tissues of poplar by real-time quantitative PCR, Agrobacterium tumefaciensmediated leaf disc transformation in poplar ‘ 84K’ was adopted to obtain PagTOP2b-overexpression transgenic plants with observations made of the effects of overexpression of PagTOP2b gene on the growth and development of plants employing a phenotypic and anatomic analysis. [Result] The coding sequence(CDS)length of the PagTOP2b gene cloned by using poplar ‘84K’ cDNA as the template was 4 449 bp, encoding1 482 amino acids. According to protein domain analysis, it is classified as type ⅡA DNA topoisomerase.PagTOP2b was mainly expressed in immature and younger tissues of poplar. Overexpression of PagTOP2b gene resulted in a significant increase in height, basal internode diameter and xylem width of transgenic plants.[Conclusion] As an important functional enzyme involved in basic life activities, the overexpression of typeⅡA DNA topoisomerase gene PagTOP2b in poplar can significantly promote the longitudinal and radial growth in plant, thus increasing plant biomass. [Ch, 4 fig. 1 tab. 28 ref.]

关 键 词：DNA拓扑异构酶 银腺杨‘84K’ 过量表达 生物量 

分 类 号：S722[农业科学—林木遗传育种] Q78[农业科学—林学]