黄麻U6启动子克隆及其转录活性分析  

Cloning and transcriptional activity analysis of U6 promoter in jute (Corchorus capsularis)

作　　者：黄梦欣 庄灵玲 程佩佩 李秦 徐建堂[1,2] 陶爱芬[1,2] 方平平[1,2] 祁建民[1,2] 张立武[1,2] HUANG Meng-Xin;ZHUANG Ling-Ling;CHENG Pei-Pei;LI Qin;XU Jian-Tang;TAO Ai-Fen;FANG Ping-Ping;QI Jian-Min;ZHANG Li-Wu(Key Laboratory of Ministry of Education for Genetics,Breeding and Multiple Utilization of Crops,Fujian Agriculture and Forestry University/Key Laboratory of Ministry of Agriculture and Rural Affairs for Biological Breeding of Fujian and Taiwan Crops/Fujian Key Laboratory for Crop Breeding by Design,Fuzhou 350002,Fujian,China;Experiment Station of Ministry of Agriculture and Rural Affairs for Jute and Kenaf Scientific Observation in Southeast China,Fujian Agriculture and Forestry University/Public Platform of Fujian for Germplasm Resources of Bast Fiber Crops/Fujian International Science and Technology Cooperation Base for Genetics,Breeding and Multiple Utilization Development of Southern Economic Crops,Fuzhou 350002,Fujian,China)

机构地区：[1]福建农林大学作物遗传育种与综合利用教育部重点实验室/农业农村部闽台作物生物育种重点实验室/福建省作物设计育种重点实验室,福建福州350002 [2]福建农林大学农业农村部东南黄红麻科学观测实验站/福建省麻类种质资源共享平台/福建省南方经济作物遗传育种与多用途开发国际科技合作基地,福建福州350002

出　　处：《作物学报》2025年第5期1156-1165,共10页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(32472219);福建省自然科学基金项目(2023J01443);财政部和农业农村部国家现代农业产业技术体系建设专项(CARS-16);福建农林大学科技创新专项基金(KFB23001,KFB24080)资助。

摘　　要：U6启动子是CRISPR/Cas9体系中驱动单向导RNA (single guide RNA, sgRNA)转录的重要元件,内源U6启动子相比外源U6启动子通常具有更高的启动效率。然而,目前黄麻内源U6启动子的研究还尚未见报道。本研究利用拟南芥保守的sgRNA AtU6-26序列,从黄麻“梅峰4号”基因组中克隆到相似性最高的CcU6.1与CcU6.3两个候选启动子。通过构建CcU6.1与CcU6.3分别驱动GUS报告基因的融合表达载体,利用农杆菌介导的转化法分别转染本氏烟草叶片和黄麻毛状根,通过GUS组织化学染色分析启动子的转录活性。同源比对结果显示,CcU6.1与CcU6.3启动子均具有影响U6启动子转录活性的2个必要元件USE和TATAbox。GUS组织化学染色表明,黄麻这2个U6启动子均具有转录活性,但在烟草叶片和黄麻毛状根中CcU6.1启动子的转录活性均弱于CcU6.3启动子,荧光定量PCR进一步验证了这一结果。考虑到过长的U6启动子可能会削弱其转录活性,于是比较分析CcU6.3与AtU6-26启动子的顺式作用元件,发现CcU6.3启动子5′端截短后的序列即从转录起始位点至–550bp位置,可能会进一步提高其转录活性。本研究率先在黄麻中克隆到具有较高转录活性的U6启动子CcU6.3,为构建黄麻属CRISPR/Cas9基因编辑系统提供了应用潜力的启动子。The U6 promoter is a critical element for driving the transcription of single guide RNA(sgRNA)in the CRISPR/Cas9 system,with endogenous U6 promoters often exhibiting higher efficiency than exogenous ones.However,no studies to date have focused on endogenous U6 promoters in jute(Corchorus L.).In this study,two candidate U6 promoters,CcU6.1 and CcU6.3,were cloned from the genome of the jute cultivar“Meifeng 4”using conserved sequences from the Arabidopsis thaliana U6-26 sgRNA promoter(AtU6-26).Fusion expression vectors carrying GUS reporter genes driven by the CcU6.1 and CcU6.3 promoters were constructed,and the transcriptional activities of these promoters were evaluated through Agrobacterium-mediated transfor-mation of tobacco(Nicotiana benthamiana)leaves and jute hairy roots.Promoter activity was determined based on GUS histo-chemical staining.Homology analysis revealed that both CcU6.1 and CcU6.3 promoters contained two essential elements for U6 promoter activity:the USE and TATA boxes.GUS staining demonstrated that both jute U6 promoters exhibited transcriptional activity,although the CcU6.1 promoter showed weaker activity compared to the CcU6.3 promoter in both Nicotiana benthamiana leaves and jute hairy roots.Quantitative PCR further confirmed these findings.Since excessively long U6 promoters may reduce transcriptional efficiency,a comparative cis-regulatory element analysis of the CcU6.3 promoter and the AtU6-26 promoter were conducted.This analysis suggested that a truncated version of the CcU6.3 promoter,spanning from the transcriptional start site to the–550 bp region,could enhance transcriptional activity.This study is the first to identify and characterize the CcU6.3 promoter,which exhibits relatively high transcriptional activity in jute.The CcU6.3 promoter holds significant potential as a strong and efficient promoter for constructing CRISPR/Cas9 gene-editing systems in Corchorus species.

关 键 词：黄麻 U6启动子 CRISPR/Cas9 本氏烟草 毛状根 转录活性 

分 类 号：S563.9[农业科学—作物学]