木薯MeHsfB3a基因的克隆及其抗细菌性枯萎病功能鉴定  

Cloning of Cassava MeHsfB3a Gene and Identification of Its Resistance to Cassava Bacterial Blight

作　　者：李琳琳 王超群 李春霞[1] 骆凯 王红刚 陈银华[1] 张肖飞 耿梦婷[1] LI Linlin;WANG Chaoqun;LI Chunxia;LUO Kai;WANG Honggang;CHEN Yinhua;ZHANG Xiaofei;GENG Mengting(College of Tropical Crops,Hainan University,Haikou,Hainan 570228,China;International Center for Tropical Agriculture,Cali AA 6713,Colombia)

机构地区：[1]海南大学热带作物学院,海南海口570228 [2]国际热带农业中心,哥伦比亚卡利AA 6713

出　　处：《热带作物学报》2023年第1期9-16,共8页Chinese Journal of Tropical Crops

基　　金：海南大学世界一流学科建设经费专项(No.RZZX201907);海南省自然科学基金项目(No.320RC492);国家木薯产业技术体系(No.CARS-11-HNCYH)。

摘　　要：木薯是热带地区重要的粮食作物,菜豆黄单胞菌属木薯细菌性枯萎病致病种(Xanthomonas phoseoli pv.manihotis,Xpm)侵染引起的细菌性枯萎病是木薯的重要病害。挖掘、鉴定木薯抗Xpm病原菌侵染的基因,并解析其抗病机制有利于开发木薯抗病种质。植物热激转录因子(heat shock transcription factors,Hsfs)在植物抵御生物胁迫和非生物胁迫的过程中发挥重要作用。本研究利用RT-PCR技术从‘华南8号’(‘SC8’)木薯品种克隆热激蛋白转录因子基因MeHsfB3a的全长。生物信息学分析发现MeHsfB3a含有2个外显子和1个内含子,全长729 bp,编码242个氨基酸,蛋白理论相对分子质量27.9 kDa,理论等电点pI为7.59,理论不稳定系数为56.86,属于不稳定蛋白质,亲水性平均指数-0.880,表明该蛋白水溶性较好,脂溶指数为65.98。亚细胞定位预测该蛋白可定位于细胞核。利用qRT-PCR技术分析发现MeHsfB3a在嫩叶、成熟叶、顶芽、叶柄、块根、须根均有表达,在成熟叶中的表达量最高,在其他器官中的表达量较少。采用Xpm HN11病原菌侵染木薯‘SC8’叶片0、3、6 h和1、3、6 d后分析MeHsfB3a表达,发现1 d以后该基因的表达显著提高。说明MeHsfB3a参与‘SC8’木薯对Xpm HN11病原菌的响应过程。采用VIGS技术沉默木薯‘SC8’的MeHsfB3a基因,该基因沉默效率降低了68.26%~82.44%。接种Xpm HN11病原菌至沉默植株叶片,于接菌0、3、6 d进行发病情况分析,发现沉默植株的病斑面积显著高于对照。本研究鉴定了热击蛋白转录因子基因MeHsfB3a参与木薯抗Xpm HN11病原菌侵染的过程,有助于进一步解析木薯对细菌性枯萎病的抗病机理。Cassava is an important food crop in tropical regions.Cassava bacterial blight caused by Xanthomonas phoseoli pv.manihotis(Xpm)is an important disease of cassava.Excavating and identifying the genes of cassava resistance to Xpm and analyzing its disease resistance mechanism are beneficial to the development of cassava disease-resistant germplasm.Plant heat shock transcription factors(Hsfs)play an important role in the process of plants resisting biotic and abiotic stresses.In this study,the full-length heat shock protein transcription factor gene MeHsfB3a was cloned from cassava cultivar‘Huanan 8’(‘SC8’)by RT-PCR technology.Bioinformatics analysis found that MeHsfB3a contained two exons and one intron,with a full length of 729 bp,encoding 242 amino acids with 27.9 kDa and pI=7.59.The theoretical instability coefficient was 56.86,which is an unstable protein,and the average hydrophilicity index was-0.880,indicating that the protein has good water solubility,and the fat solubility index was65.98.The protein was predicted to localize in the nucleus.qRT-PCR analysis found that MeHsfB3a was expressed in young leaves,mature leaves,terminal buds,petioles,tuberous roots and fibrous roots,with the highest expression in mature leaves and less in other organs.The expression of MeHsfB3a was analyzed after 0 h,3 h,6 h,1 d,3 d and 6 d after infection of cassava‘SC8’leaves by pathogen Xpm HN11,and it was found that the expression of this gene was significantly increased after 1 d.This indicated that MeHsfB3a was involved in the response of‘SC8’cassava to Xpm HN11.The MeHsfB3a gene of cassava‘SC8’was silenced by the VIGS technology,and the gene silencing efficiency reached 68.26%-82.44%.The leaves of silent plants were inoculated with Xpm HN11,and the disease incidence was analyzed on 0 d,3 d,and 6 d of inoculation,and it was found that the area of disease spots of the silent plants was significantly higher than that of the control.This study identified the heat shock protein transcription factor gene MeHsfB3

关 键 词：热激转录因子 基因表达 VIGS MeHsfB3a基因 

分 类 号：S533[农业科学—作物学] S435.33