Anthocyanins are important compounds for fruit quality and nutrition. The R2R3 MYB transcription factor PpMYB10.1 is known to be critical for regulating anthocyanin accumulation in peach. However, regulatory factors upstream of PpMYB10.1 which control temperature-dependent, cultivar-contrasted and tissue-specific anthocyanin accumulation remain to be determined. In this study, differential anthocyanin accumulation in the outer flesh near the peel (OF) of peach [Prunus persica (L.) Batsch] was observed between cultivars “Zhonghuashoutao” and “Dongxuemi”, as well as among different storage temperatures and different fruit tissues of “Zhonghuashoutao”. By cross-comparisons of RNA-Seq data of samples with differential anthocyanin accumulation, transcription factor genes PpBBX32 and PpZAT5 were identified. These were functionally characterized as two positive regulators for anthocyanin accumulation via transient expression and genetic transformation. Various interaction assays revealed that both PpBBX32 and PpZAT5 can directly activate the PpMYB10.1 promoter and meanwhile interact at protein level as a PpZAT5-PpBBX32-PpMYB10.1 complex. Furthermore, the results of in silico analysis and exogenous application of methyl jasmonate (MeJA) indicated that MeJA favored anthocyanin accumulation, while it was also found that anthocyanin accumulation as well as PpBBX32 and PpZAT5 expression correlated significantly with endogenous JA and JA-Ile in different fruit tissues. In summary, PpBBX32 and PpZAT5 are upstream activators of PpMYB10.1, allowing JAs to take part in temperature-dependent and tissue-specific anthocyanin accumulation by modulating their expression. This work enriches the knowledge of the transcriptional regulatory mechanisms for differential anthocyanin accumulation under internal and external factors.

中文翻译：

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PpBBX32 和 PpZAT5 调节桃果实中温度依赖性和组织特异性花青素的积累


花青素是水果品质和营养的重要化合物。 R2R3 MYB 转录因子 PpMYB10.1 已知对于调节桃花青素积累至关重要。然而，PpMYB10.1 上游控制温度依赖性、品种对比和组织特异性花青素积累的调节因素仍有待确定。本研究观察了桃[Prunus persica (L.) Batsch]品种“中华寿桃”和“冬雪蜜”之间以及不同贮藏温度和不同果实之间靠近果皮（OF）的外果肉中花青素积累的差异。 “中华寿桃”纸巾。通过对具有差异花青素积累的样品的RNA-Seq数据进行交叉比较，鉴定出转录因子基因PpBBX32和PpZAT5。这些在功能上被描述为通过瞬时表达和遗传转化来调节花青素积累的两个正调节因子。各种相互作用测定表明，PpBBX32和PpZAT5都可以直接激活PpMYB10.1启动子，同时作为PpZAT5-PpBBX32-PpMYB10.1复合物在蛋白质水平上相互作用。此外，计算机分析和外源应用茉莉酸甲酯（MeJA）的结果表明，MeJA有利于花青素的积累，同时还发现花青素的积累以及PpBBX32和PpZAT5的表达与不同植物中的内源JA和JA-Ile显着相关。水果组织。总之，PpBBX32 和 PpZAT5 是 PpMYB10.1 的上游激活剂，允许 JAs 通过调节其表达来参与温度依赖性和组织特异性花青素的积累。 这项工作丰富了人们对内部和外部因素下差异花青素积累的转录调控机制的认识。