Carbon Starved Anther Encodes a MYB Domain Protein That Regulates Sugar Partitioning Required for Rice Pollen Development
Carbon Starved Anther Encodes a MYB Domain Protein That Regulates Sugar Partitioning Required for Rice Pollen Development
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碳饥饿的花药编码一种 MYB 结构域蛋白，该蛋白调节水稻花粉发育所需的糖分配
DOI：
10.1105/tpc.109.073668
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发表时间：
2010-03-01
期刊：
影响因子：
11.6
通讯作者：
Zhang, Dabing
中科院分区：
文献类型：
--
作者：
Zhang, Hui;Liang, Wanqi;Zhang, Dabing
在开花植物中，汇组织依靠来自光合作用组织(源)的碳水化合物的运输来获得营养和能量。然而，在植物发育过程中，糖的分配是如何在分子水平上被调节的仍是未知的。我们分离并鉴定了一个水稻突变体，缺碳花药(Csa)，该突变体表现出叶和茎中糖含量增加，花器官中糖和淀粉水平降低。特别是，CsA突变体降低了后期花药中的碳水化合物水平，是雄性不育的。CsA突变体减少了C-14标记的糖在花药库组织中的积累。通过基于MAP的克隆获得了CsA，并编码了一个R2R3MYB转录因子，该转录因子在花药绒被细胞和糖运输的维管组织中优先表达。此外，编码单糖转运蛋白的MST8在CsA花药中的表达大大降低。此外，CsA在体内和体外都与MST8的启动子相关。我们的研究结果表明，CSA在水稻雄性生殖发育过程中是糖分配的关键转录调节因子。本研究还建立了一个分子模型系统，以进一步阐明植物碳分配的遗传控制。
In flowering plants, sink tissues rely on transport of carbohydrates from photosynthetic tissues (sources) for nutrition and energy. However, how sugar partitioning in plants is regulated at the molecular level during development remains unknown. We have isolated and characterized a rice (Oryza sativa) mutant, carbon starved anther (csa), that showed increased sugar contents in leaves and stems and reduced levels of sugars and starch in floral organs. In particular, the csa mutant had reduced levels of carbohydrates in later anthers and was male sterile. The csa mutant had reduced accumulation of C-14-labeled sugars in anther sink tissue. CSA was isolated by map-based cloning and was shown to encode an R2R3 MYB transcription factor that was expressed preferentially in the anther tapetal cells and in the sugar-transporting vascular tissues. In addition, the expression of MST8, encoding a monosaccharide transporter, was greatly reduced in csa anthers. Furthermore, CSA was found to be associated in vivo and in vitro with the promoter of MST8. Our findings suggest that CSA is a key transcriptional regulator for sugar partitioning in rice during male reproductive development. This study also establishes a molecular model system for further elucidation of the genetic control of carbon partitioning in plants.