Rice DECUSSATE controls phyllotaxy by affecting the cytokinin signaling pathway
Rice DECUSSATE controls phyllotaxy by affecting the cytokinin signaling pathway
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DOI：
10.1111/j.1365-313x.2012.05123.x
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发表时间：
2012-12-01
期刊：
影响因子：
7.2
通讯作者：
Nagato, Yasuo
中科院分区：
文献类型：
--
作者：
Itoh, Jun-ichi;Hibara, Ken-ichiro;Nagato, Yasuo
叶序性定义为叶在茎上的空间排列。负责这种极其规则的模式的机制是植物生物学中最迷人的谜团之一。在这项研究中，我们确定了一个基因调控叶序格局在水稻。功能丧失突变体的DEXYSATE（DEC）基因表现出叶序转换从正常的二列图案交互对生。dec突变体茎尖分生组织增大，细胞分裂活性增强。与茎顶端分生组织相比，dec突变体的根顶端分生组织缩小，细胞分裂活性受到抑制。这些表型表明DEC在茎尖分生组织和根尖分生组织中具有相反的功能。图位克隆显示DEC编码一种植物特异性蛋白，含有一个富含谷氨酰胺的区域和一个保守的基序。虽然其分子功能尚不清楚，但其保守结构域与真菌和动物共有。表达分析表明，在细胞分裂素信号通路中起作用的几个A型反应调节基因在dec突变体中下调。此外，DEC幼苗对外源细胞分裂素的反应性降低。我们的研究结果表明，DEC控制叶序格局通过影响细胞分裂素信号在水稻。
Phyllotaxy is defined as the spatial arrangement of leaves on the stem. The mechanism responsible for this extremely regular pattern is one of the most fascinating enigmas in plant biology. In this study, we identified a gene regulating the phyllotactic pattern in rice. Loss-of-function mutants of the DECUSSATE (DEC) gene displayed a phyllotactic conversion from normal distichous pattern to decussate. The dec mutants had an enlarged shoot apical meristem with enhanced cell division activity. In contrast to the shoot apical meristem, the size of the root apical meristem in the dec mutants was reduced, and cell division activity was suppressed. These phenotypes indicate that DEC has opposite functions in the shoot apical meristem and root apical meristem. Map-based cloning revealed that DEC encodes a plant-specific protein containing a glutamine-rich region and a conserved motif. Although its molecular function is unclear, the conserved domain is shared with fungi and animals. Expression analysis showed that several type A response regulator genes that act in the cytokinin signaling pathway were down-regulated in the dec mutant. In addition, dec seedlings showed a reduced responsiveness to exogenous cytokinin. Our results suggest that DEC controls the phyllotactic pattern by affecting cytokinin signaling in rice.