毛竹Phyllostachys edulis retrotransposon 7(PHRE7)转座子的克隆与鉴定  

Cloning and characterization of a long terminal repeat retrotransposon(Phyllostachys edulis retrotransposon 7) in Phyllostachys edulis

作　　者：蒋政勤 周明兵[1,2] 郑浩[1] 季航 徐芷馨 JIANG Zhengqin;ZHOU Mingbing;ZHENG Hao;JI Hang;XU Zhixin(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China;Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-efficiency Utilization,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China)

机构地区：[1]浙江农林大学省部共建亚热带森林培育国家重点实验室,浙江杭州311300 [2]浙江农林大学浙江省竹资源与高效利用协同中心,浙江杭州311300

出　　处：《浙江农林大学学报》2019年第5期917-927,共11页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目（31870656,31470615）;浙江省大学生科技创新活动计划暨新苗人才计划资助项目(2018R412004)

摘　　要：长末端重复序列(LTR)反转录转座子广泛存在于植物基因组中,本质是一段可移动的脱氧核糖核酸(DNA)序列。大多数LTR反转录转座子在外界环境变化下能够被激活转录,对环境变化做出响应。为研究毛竹基因组中的LTR反转录转座子的转录活性及在非生物环境胁迫下表达量的具体变化,克隆和鉴定了1个毛竹Phyllostachys edulis反转录转座子PHRE7。该转座子全长为6 073 bp,属于Ty1-copia家族中的Tork分支,LTR序列相似性为96.7%,插入时间为126.923万a前。对毛竹实生苗分别进行辐照(30,50,70 Gy),甲基化抑制剂(50,100,150μmol·L^-1),高温(42℃),低温(4℃),高盐(0.1,0.2,0.3 mol·L^-1)等5种不同胁迫处理,通过定量荧光聚合酶链式反应(PCR)检测,PHRE7在INT,RT和RH等3个结构域中的表达量仅在辐照及0.2~0.3 mol·L^-1高盐处理下随处理强度的上升而下降,其余所有处理(甲基化抑制剂、高温、低温、高盐0.1~0.2 mol·L^-1)的表达量都随处理强度呈上升趋势。这些结果表明:PHRE7转座子是一个具有转录活性的LTR反转录转座子,且外界非生物环境胁迫对其表达模式有较大影响,表明PHRE7转座子能够响应外界环境变化。Long terminal repeats(LTR)retrotransposons,a type of mobile DNA sequence widely found in plant genomes,could be activated and transposed in response to changes in the environment.To study the transcriptional activity of LTR retrotransposons in the genome of Phyllostachys edulis and to determine the specific changes of their expression under abiotic stress,an LTR retrotransposon in Phyllostachys edulis(PHRE 7)was cloned and characterized.The total length of the transposon was 6 073 bp,belonging to the Tork branch in the Ty1-copia family.The homology of the LTR sequence was 96.7%with an insertion time of about 1.269 million years ago.The experiment had five different treatments including irradiation(30,50,and 70 Gy),methylation inhibitor(50,100,and 150μmol·L^-1),high temperature(42℃),low temperature(4℃)and salt stress(0.1,0.2,and 0.3 mol·L^-1)on Phyllostachys edulis seedlings.Real-time fluorescence quantitative PCR was used for the analysis of relative expression of transposon domains including RT(Reverse Transcriptase)protein domain,RH(Ribonuclease H)protein domain and INT(Integrase)protein domain in PHRE7.Results detected by real-time fluorescence quantitative PCR showed that under the conditions of low/high temperature,methylation inhibitors and the salt concentration(0.1-0.2 mol·L^-1),the expression level of three domains(INT,RT,RH)of PHRE 7 were increased and the expression level under irradiation dose and the salt concentration(0.2-0.3 mol·L^-1)were decreased.Thus,the PHRE 7 transposon was a transcriptionally active LTR retrotransposon,and the abiotic environmental stress had a great influence on its expression pattern indicating that the PHRE 7 transposon could respond to external environmental changes;however,the specific response mechanism,not yet being clear,means further research and analysis are still needed.

关 键 词：植物学 毛竹 LTR反转录转座子 生物信息学 逆境胁迫 转录活性 

分 类 号：S718.3[农业科学—林学] S795.72