摘要
为探究MYB转录因子对甜荞花色苷合成的负调控作用,以拟南芥负调控花色苷合成的MYB转录因子基因AtMYBL2为参考序列,在甜荞基因组中筛选出1个同源基因,命名为FeMYB18。以甜荞‘贵红甜2号’为实验材料,克隆FeMYB18基因,对其进行序列特征、系统进化、组织特异性表达和亚细胞定位分析,并构建过表达载体转化野生型拟南芥分析其功能。结果表明FeMYB18的CDS序列全长732 bp,编码243个氨基酸,推测其分子量为27.469 kDa,理论等电点为8.76,FeMYB18蛋白含有R2、R3保守结构域,还有C1、C2、C5以及结合bHLH的保守基序。系统进化分析表明FeMYB18与苦荞负调控花色苷合成的Ft MYB18同源关系最近,均属于MYB-SG4亚家族。FeMYB18亚细胞定位于细胞核,在拟南芥中过表达FeMYB18基因,幼苗花色苷含量显著低于野生型拟南芥,同时,花色苷合成途径上的结构基因AtDFR、At ANS和AtUFGT的表达水平显著下调。因此推测FeMYB18可能通过抑制花色苷合成途径的相关基因的表达水平进而负调控花色苷的积累。该研究结果为进一步研究甜荞的着色机制奠定了良好的基础。
Aims:Anthocyanins contribute the red flower color,nutritional quality and abiotic/biotic stress tolerance in common buckwheat(Fagopyrum esculentum),nevertheless,its biosynthesis regulation mechanism in common buckwheat remains unclear.Methods:Here,an MYB transcription factor gene FeMYB18 was chosen through homologous alignment using Arabidopsis AtMYBL2 in common buckwheat genome data.Then,FeMYB18 was cloned from common buckwheat cultivar'Guihongtian 2',and performed to sequence characteristics,phylogenetic,tis sue-specific expression and subcellular localization analysis.Meanwhile,its function in regulation anthocyanin biosynthesis was verified by overexpression in wild Arabidopsis.Results:The results suggested that the full length CDS of FeMYB18 is 732 bp,encoding 243 amino acids,with predicted molecular weight 27.469 kDa and isoelectric point 8.76.FeMYB18 is most closely homologous to FtMYB18,which is a negative regulator of anthocyanin biosynthesis in Tartary buckwheat,and they both belong to the MYB-SG4 subfamily and contain R2,R3,suppression motif C5 and bHLH-binding conserved domains.The expression profiles of FeMYB18 were negative correlation with the anthocyanins content in stems and leaves of'Guihongtian 2'.FeMYB18 locates in the nucleus,and when FeMYB18 is overexpressed in Arabidopsis,no pigment accumulated in the seedlings in transgenic seedlings,and the anthocyanin content is significantly lower than that in the wild-type Arabidopsis.Meanwhile,the expression levels of the structural genes AtDFR,AtANS and AtUFGT in the anthocyanin synthesis pathway are significantly down-regulated in transgenic plants.In summary,FeMYB18 may negatively regulate anthocyanin accumulation by suppressing the expression levels of anthocyanin biosynthesis-related genes.Conclusion:These findings enrich the regulation mechanism of anthocyanin biosynthesis and lay foundation for further research on regulatory network.It will also facilitate the breeding of common buckwheat cultivars with high anthocyanin content and nutrition.
作者
陈红
张兰
杨朝结
梁红艳
陈庆富
邓娇
CHEN Hong;ZHANG Lan;YANG Chaojie;LIANG Hongyan;CHEN Qingfu;DENG Jiao(Buckwheat Engineering Technology Research Center,College of Life Sciences,Guizhou Normal University,Guiyang 550025,China)
出处
《植物生理学报》
北大核心
2026年第1期71-81,共11页
Plant Physiology Journal
基金
贵州省特色杂粮生物育种全省重点实验室(黔科合平台ZSYS[2025]026)
贵州省科技计划项目(黔科合基础-ZK[2023]一般278)
国家现代农业产业技术体系荞麦育种岗位科学家专项资金(CARS-07-A5)。
关键词
甜荞
FeMYB18
MYB
花色苷
buckwheat(Fagopyrum esculentum)
FeMYB18
MYB
anthocyanins
