紫心甘薯IbMYB1上游7个调控蛋白的互作与表达分析

Interaction and Expression Analysis of 7 Transcription Proteins Upstream of IbMYB1 in Purple-Fleshed Sweet Potato

【目的】对前期筛选到的紫心甘薯IbMYB1上游7个调控蛋白(IbERF1、IbPDC、IbPGP19、IbSCF、IbWRKY1、IbJOX4和IbEIN3-2)的互作与表达进行分析,进一步阐明花色素苷在特定时空合成与积累的调控网络。【方法】采用酵母双杂交和双分子荧光互补试验,对7个调控因子之间的相互作用进行检测,使用荧光定量PCR对紫心甘薯和白心甘薯根不同发育时期花色素苷合成调控和筛选的上游调控因子进行基因表达特征分析。【结果】IbERF1与IbSCF、IbWRKY1存在相互作用。双分子荧光互补试验证实了酵母双杂交的试验结果。IbERF1基因在紫心甘薯根不同时期的表达量均低于白心甘薯,且随着根中花色素苷的积累其表达量逐渐降低,IbWRKY1和IbSCF基因在紫心甘薯和白心甘薯根不同发育时期中的表达量,与花色素苷的积累无明显的相关关系。【结论】IbMYB1上游调控蛋白IbERF1、IbSCF可分别与IbWRKY1形成复合物,以转录复合体的形式共同调控IbMYB1表达。推测IbERF1可能负调控花色素苷的合成,IbSCF和IbWRKY1参与紫心甘薯花色素苷的合成与调控,可能还存在更为复杂的机制。

【Objective】The interaction and expression of 7 upstream transcription proteins(IbERF1,IbPDC,IbPGP19,IbSCF,IbWRKY1,IbJOX4 and IbEIN3-2)of purple-fleshed sweet potato IbMYB1 were analyzed to further elucidate the regulatory network of anthocyanin synthesis and accumulation in specific time and space.【Method】Yeast two-hybrid and BiFC experiment were used to detect the interactions between the 7 upstream transcription regulators.RT-qPCR was used to analyze the gene expression traits of an thocyanin synthesis regulation and upstream regulators in purple-fleshed sweet potato and white-fleshed sweet potato at roots different developmental stages.【Result】IbERF1 interacted with IbSCF and IbWRKY1.BiFC experiment confirmed the results of yeast two-hybrid experiment.The expression level of IbERF1 gene in purple-fleshed sweet potato roots was lower than that in white-fleshed sweet potato at different periods,and the expression level decreased gradually with the accumulation of anthocyanin in root.The expression levels of IbWRKY1 and IbSCF genes in the roots of purple-fleshed sweet potato and white-fleshed sweet potato at different developmental stages showed no significant positive or negative correlation with anthocyanin accumulation.【Conclusion】The upstream regulatory proteins IbERF1 can form a complex with IbSCF and IbWRKY1,respectively to co-regulate the expression of IbMYB1 in the form of a transcription complex.It is speculated that IbERF1 may negatively regulate anthocyanin synthesis,and IbSCF and IbWRKY1 may be involved in the synthesis and regulation of anthocyanin in purple-fleshed sweet potato.