彩色马铃薯花青素生物合成相关microRNAs及其靶基因表达分析

Transcriptional Analysis of microRNAs and Their Target Genes Relevant to Anthocyanin Biosynthesis in Pigmented Potatoes

MicroRNAs(miRNAs)是植物中具有调控功能的非编码小RNA,可调节植物生长发育、次生代谢及胁迫响应。为挖掘彩色马铃薯花青素合成相关的miRNAs,本研究基于miRNA和降解组测序数据,对筛选出和花青素相关的miRNA及靶基因进行鉴定,分析其理化性质、蛋白质结构、调控关系及在不同彩色马铃薯品种的表达。结果表明:stu-miR156a_R-1_StSPL9、stu-miR828_StMYB3、stu-miR858_StMYB4、stu-miR5021_StMYB在马铃薯块茎的不同发育时期存在显著的负相关关系。不同彩色马铃薯品种中,stu-miR828负调控靶基因StMYB3,抑制花青素合成;stu-miR156a_R-1负调控靶基因StSPL9,促进花青素合成。stu-miR858负调控靶基因StMYB4,在紫色马铃薯中促进花青素合成,在红色马铃薯中抑制花青素合成。stu-miR5021负调控靶基因StMYB,在紫色马铃薯中抑制花青素合成,在红色马铃薯中促进花青素合成。

MicroRNAs are non-coding small RNAs with regulatory functions,which modulate the growth and development,secondary metabolism and stress response in plants. To explore the miRNAs that are relevant to anthocyanin synthesis in pigmented potatoes,in this study the miRNAs and their target genes were identified using small RNA(sRNA)and degradome sequencing. The physicochemical properties,protein structure,regulatory relationship and expression of miRNAs and target genes in pigmented potato cultivars were analyzed. The results showed that,the miRNA/target gene pair stu-miR156a_R-1/StSPL9,stu-miR828/StMYB3,stu-miR858/StMYB4and stu-miR5021/StMYB were found with significant negative correlation at different developmental stages in potato tubers. For examples,the miRNA stu-miR828 might negatively regulate the target gene StMYB3,thus inhibiting anthocyanin synthesis,while stu-miR156a_R-1 might promote anthocyanin synthesis via negatively regulating the target gene StSPL9. stu-miR858 was able to negatively regulate the target gene StMYB4,which could promote anthocyanin synthesis in purple potato cultivars and inhibit anthocyanin synthesis in red potato cultivars. stu-miR5021 was a negative regulator for the target gene stMYB,thus suppressing anthocyanin synthesis in purple potato,whereas promoting anthocyanin synthesis in red potato.