百日草花青素苷合成相关MYB转录因子筛选及ZeMYB9功能研究

Identification and Expression Analysis of MYB Transcription Factors Regulating the Anthocyanin Biosynthesis in Zinnia elegans and Function Research of ZeMYB9

以百日草‘梦境红色’作为试验材料,基于其转录组初步鉴定出33个MYB转录因子。系统进化树分析,鉴定出10个可能参与调控花青素苷合成的R2R3-MYB蛋白,其中S4亚族5个、S6亚族3个、S7亚族2个。结合这10个MYB基因表达和花瓣花青素苷含量变化结果,推测S4亚族Ze MYB32可能负调控花青素苷的合成,而Ze MYB3和Ze MYB16可能促进花青素苷的积累。此外,S6亚族Ze MYB9和Ze MYB10可能正调控花青素苷的合成。进一步研究发现,Ze MYB9定位于细胞核内。烟草中过表达Ze MYB9显著促进其叶片花青素苷的积累,花青素苷合成相关基因上调表达,表明Ze MYB9正向调控花青素合成。

In this study,Zinnia elegans‘Dreamland Red’was employed as plant materials,and 33 MYB transcription factors were screened based on the transcriptome data of Z.elegans.Furthermore,phylogenetic tree analysis revealed that ten R2R3-MYB transcription factors probably related to anthocyanin synthesis were identified in Z.elegans.Among them,five MYB proteins of Z.elegans belonged to subgroup 4(S4),three MYB proteins were clustered in S6,and two MYB proteins were included in S7.According to combined analysis on gene expression levels of ten MYB genes and anthocyanidin content in Z.elegans‘Dreamland Red’,it was suggested that Ze MYB32 of S4 probably negatively regulated anthocyanin synthesis in Z.elegans,while Ze MYB3 and Ze MYB16 promoted the accumulation of anthocyanin.What’s more,Ze MYB9 and Ze MYB10 of S6 probably positively regulated anthocyanin synthesis.Further research found that Ze MYB9 is located in the nucleus.Overexpression of Ze MYB9 gene in tobacco enhanced the marked accumulation of anthocyanins in leaves,and dramatically up-regulated the expression levels of all detected genes related with anthocyanin synthesis,revealing that Ze MYB9 plays a positive role in anthocyanin biosynthesis.