《植物生理学报》 2013, 49(2): 188-194

拟南芥MicroRNA828负调控蔗糖诱导的花青素合成

谢烨, 孙毅, 李淡宁, 黄继荣*

中国科学院上海生命科学研究院植物生理生态研究所, 上海200032

通信作者：黄继荣；E-mail: huangjr@sibs.ac.cn；Tel: 021-54924145

摘　要：

花青素生物合成途径及转录调控因子虽然已基本被阐明, 但其调控机理仍在日益更新。本研究利用蔗糖诱导花青素合成的表型, 建立了一种筛选拟南芥花青素代谢突变体的方法。我们从T-DNA插入突变体库中筛选出一株花青素合成过量突变体, 基因克隆结果表明是由MicroRNA828 (miR828)的功能缺失所致。进一步研究发现miR828过表达植株中蔗糖诱导的花青素积累较野生型减少, 这与敲除miR828的靶基因TAS4导致花青素积累比野生型高的结果一致, 表明miR828负调控花青素合成。miR828在各组织中表达量很低, 但其表达受到蔗糖诱导。在讨论中, 我们提出了miR828调控蔗糖诱导花青素合成的模型

关键词：花青素; miR828; TAS4; 蔗糖; 负调控

收稿：2012-12-19   修定：2012-12-28

资助：国家科技部“973”项目(2013CB127000)。

MicroRNA828 Negatively Regulates Sucrose-Induced Anthocyanin Biosynthe-sis in Arabidopsis

XIE Ye, SUN Yi, LI Dan-Ning, HUANG Ji-Rong*

Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China

Corresponding author: HUANG Ji-Rong; E-mail: huangjr@sibs.ac.cn; Tel: 021-54924145

Abstract:

Anthocyanins displaying from red, blue to purple give plants a colorful world. They play an impor-tant role in pollination, seed dispersal, and stress resistance. Although the anthocyanin biosynthetic pathway and the transcription factors have been well-documented, regulatory mechanisms underlying anthocyanin bio-synthesis are not fully understood. In this study, we established a system to screen mutants with high accumula-tion of anthocyanin in Arabidopsis thaliana, and provided new evidence that small RNA is involved in antho-cyanin biosynthesis. Using the phenomenon of sugar-induced anthocyanin biosynthesis, we obtained a mutant accumulated a higher level of anthocyanin compared with the wild type (WT). TAIL-PCR analysis revealed that the phenotype was resulted from the loss-of-function microRNA828 (miR828). Consistently, anthocyanin con-tent was reduced in miR828 overexpressors under sucrose treatment. In addition, knockout of TAS4, the target of miR828, also led to higher accumulation of anthocyanin in sugar-treated seedlings compared with WT. These results indicate that miR828 negatively regulates anthocyanin biosynthesis. Further analysis demonstrated that the expression level of miR828 was quite low in various tissues, but was significantly induced by sucrose. We proposed a model to explain the importance of miR828 and TAS4 in sugar-regulated anthocyanin biosynthesis.

Key words: anthocyanin; miR828; TAS4; sucrose; negative regulation