摘要
R2R3-MYB转录因子在植物非生物胁迫应答中起重要作用.从‘红阳’猕猴桃(Actinidia chinensis cv.Hongyang)中筛选并克隆R2R3-MYB转录因子家族基因AcMYB44.经生物信息学分析和在拟南芥中转基因功能验证,结果显示:(1)通过RT-PCR克隆得到AcMYB44的全长序列.qRT-PCR分析表明,AcMYB44在猕猴桃不同组织中均有表达,但在根中表达量最高;(2)AcMYB44全长870 bp,共编码289个氨基酸,蛋白质分子量(Mr)约为31.6×103,是含有2个保守SANT/MYB结构域的亲水性蛋白,属于R2R3-MYB转录因子亚家族.分子进化树显示AcMYB44与茶树、烟草和马铃薯的同源蛋白亲缘关系最近.绿色荧光蛋白(GFP)示踪结果显示AcMYB44编码蛋白定位于细胞核内.PlantCARE在线分析表明,AcMYB44启动子区域含有多个与抗逆、激素应答、光信号传递等相关的顺式作用元件;(3)构建AcMYB44植物表达载体,经农杆菌介导转化到拟南芥中,获得6个独立转基因株系.经qRT-PCR分析,AcMYB44在6个转基因株系中均有不同程度的表达.在甘露醇胁迫下,转基因株系拥有更高的萌发率和更多的根生长量.本研究表明AcMYB44能增强植物的抗旱能力,为猕猴桃抗旱品种选育提供了新的基因靶点.(图8表1参31)
The R2R3-MYB transcription factor plays an important role in the abiotic stress response in plants. To study the function of the MYB transcription factor in kiwifruit(Actinidia), a stress-resistant gene homologous to At MYB44 was identified by screening transcriptomic datasets from a kiwifruit genome database. The A. chinensis cv. Hongyang target gene was cloned and named AcMYB44, which was expressed in all kiwifruit tissues, with the highest expression level in the roots. Bioinformatics analysis showed that the length of the AcMYB44 gene is 870 bp, encoding 289 amino acids with a protein molecular weight of approximately 31.6 × 103. It contains two conserved SANT/MYB domains, indicating that the gene belongs to the R2R3-MYB transcription factor subfamily.Phylogenetic analysis showed that AcMYB44 clustered with homologous genes derived from Camellia sinensis,Nicotiana tabacum, and Solanum tuberosum. Green fluorescent signals from the AcMYB44-GFP fusion protein was detected in the nucleus. PlantCARE online analysis showed that promoter of AcMYB44 contains multiple cis-elements related to stress resistance, hormone response, and light signaling. An AcMYB44 overexpression vector was constructed and transferred into Arabidopsis thaliana using the Agrobacterium-mediated floral-dip method. Six homozygous transgenic lines were obtained, and mannitol treatment enhanced drought resistance in transgenic Arabidopsis. In general, the structure and function of AcMYB44 were revealed, which provided a theoretical basis and a new target gene for the breeding of drought-resistant kiwifruit varieties.
作者
戚钰
王梨嬛
张亚斌
程浩
刘博
刘永胜
QI Yu;WANG Lihuan;ZHANG Yabin;CHENG Hao;LIU Bo;LIU Yongsheng(Ministry of Education Key Laboratory for Bio-resource and Eco-environment,College of Life Sciences,State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610064,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2022年第4期1051-1056,共6页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(31671259)资助。
