A blueberry MIR156a-SPL12 module coordinates the accumulation of chlorophylls and anthocyanins during fruit ripening
A blueberry MIR156a-SPL12 module coordinates the accumulation of chlorophylls and anthocyanins during fruit ripening
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蓝莓 MIR156a-SPL12 模块协调果实成熟过程中叶绿素和花青素的积累
DOI：
10.1093/jxb/eraa327
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发表时间：
2020-10-07
影响因子：
6.9
通讯作者：
Bian, Shaomin
中科院分区：
文献类型：
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作者：
Li, Xuyan;Hou, Yanming;Bian, Shaomin
颜色变化是蓝莓果实成熟过程中的一个重要事件，通常取决于叶绿素的降解和花青素的积累。MicroRNA156(MiR156)-SPL模块是参与花青素生物合成调控的一组重要的调控枢纽。然而，关于它们在蓝莓中的作用或在颜色变化过程中对叶绿素代谢的作用，人们知之甚少。在本研究中，我们在蓝莓(Vaccdium CorymBosum)中发现了一个miR156基因(VcMIR156a)。VcMIR156a在番茄中的过表达通过改变色素相关基因的表达促进了番茄茎中花青素的生物合成和叶绿素的降解。进一步的研究表明，VcSPL12转录本可以被miR156定位，并且在蓝莓果实的发育和成熟过程中表现出反向积累的模式。值得注意的是，VcSPL12在绿果期高表达，而VcMIR156a转录本主要积累在白果期，此时VcSPL12的表达急剧下降，这表明VcMIR156a-VcSPL12是果实着色过程中的关键调控中心。此外，VcSPL12降低了几个花青素生物合成和调控基因的表达，酵母双杂交实验表明VcSPL12与VcMYBPA1相互作用。有趣的是，VcSPL12的表达显著促进了叶绿素的积累，并改变了几个与叶绿素相关的基因的表达。此外，VcMIR156a和VcSPL12的表达改变了叶绿体的超微结构。这些发现为miR156-SPLs在植物中的功能作用提供了新的见解，特别是在蓝莓果实着色中。
Color change is an important event during fruit maturation in blueberry, usually depending on chlorophyll degradation and anthocyanin accumulation. MicroRNA156 (miR156)-SPL modules are an important group of regulatory hubs involved in the regulation of anthocyanin biosynthesis. However, little is known regarding their roles in blueberry or in chlorophyll metabolism during color change. In this study, a MIR156 gene (VcMIR156a) was experimentally identified in blueberry (Vaccinium corymbosum). Overexpression of VcMIR156a in tomato (Solanum lycopersicum) enhanced anthocyanin biosynthesis and chlorophyll degradation in the stem by altering pigment-associated gene expression. Further investigation indicated that the VcSPL12 transcript could be targeted by miR156, and showed the reverse accumulation patterns during blueberry fruit development and maturation. Noticeably, VcSPL12 was highly expressed at green fruit stages, while VcMIR156a transcripts mainly accumulated at the white fruit stage when expression of VcSPL12 was dramatically decreased, implying that VcMIR156a-VcSPL12 is a key regulatory hub during fruit coloration. Moreover, VcSPL12 decreased the expression of several anthocyanin biosynthetic and regulatory genes, and a yeast two-hybrid assay indicated that VcSPL12 interacted with VcMYBPA1. Intriguingly, expression of VcSPL12 significantly enhanced chlorophyll accumulation and altered the expression of several chlorophyll-associated genes. Additionally, the chloroplast ultrastructure was altered by the expression of VcMIR156a and VcSPL12. These findings provide a novel insight into the functional roles of miR156-SPLs in plants, especially in blueberry fruit coloration.