DWARF10, an RMS1/MAX4/DAD1 ortholog, controls lateral bud outgrowth in rice
DWARF10, an RMS1/MAX4/DAD1 ortholog, controls lateral bud outgrowth in rice
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DOI：
10.1111/j.1365-313x.2007.03210.x
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发表时间：
2007-09-01
期刊：
影响因子：
7.2
通讯作者：
Kyozuka, Junko
中科院分区：
文献类型：
--
作者：
Arite, Tomotsugu;Iwata, Hirotaka;Kyozuka, Junko
植物结构主要由枝条分枝模式决定。顶端优势是分枝模式发育中众所周知的控制机制，但对其在水稻等单子叶植物中的作用知之甚少。在这里，我们表明顶端优势的概念可以应用于水稻分蘖芽的生长。在水稻分枝增强突变体 dwarf10 (d10) 中，可以观察到顶端优势，但顶端分生组织的抑制作用减弱。 D10 是 MAX4/RMS1/DAD1 的水稻直系同源物，编码类胡萝卜素裂解双加氧酶 8，并被认为参与了一种未鉴定的芽分枝抑制剂的合成。 D10 表达主要发生在大多数器官的血管细胞中。实时聚合酶链反应分析表明，D10 mRNA 的积累是由外源生长素诱导的。此外，D10 表达在 6 个分枝突变体 d3、d10、d14、d17、d27 和高分蘖矮化 (htd1) 中上调。对于水稻的 MAX2 和 MAX3 直系同源物 D3 或 HTD1，没有发现这种效应。这些发现意味着 D10 转录可能是分支抑制剂途径调节的关键步骤。此外，我们的观察结果表明 FINE CULM1 (FC1)（大蜀黍分支 1 (tb1) 的水稻直系同源物）可能独立于分支抑制剂途径发挥作用。
Plant architecture is mostly determined by shoot branching patterns. Apical dominance is a well-known control mechanism in the development of branching patterns, but little is known regarding its role in monocots such as rice. Here, we show that the concept of apical dominance can be applied to tiller bud outgrowth of rice. In dwarf10 (d10), an enhanced branching mutant of rice, apical dominance can be observed, but the inhibitory effects of the apical meristem was reduced. D10 is a rice ortholog of MAX4/RMS1/DAD1 that encodes a carotenoid cleavage dioxygenase 8 and is supposed to be involved in the synthesis of an unidentified inhibitor of shoot branching. D10 expression predominantly occurs in vascular cells in most organs. Real-time polymerase chain reaction analysis revealed that accumulation of D10 mRNA is induced by exogenous auxin. Moreover, D10 expression is upregulated in six branching mutants, d3, d10, d14, d17, d27 and high tillering dwarf (htd1). No such effects were found for D3 or HTD1, the MAX2 and MAX3 orthologs, respectively, of rice. These findings imply that D10 transcription might be a critical step in the regulation of the branching inhibitor pathway. In addition, we present observations that suggest that FINE CULM1 (FC1), a rice ortholog of teosinte branched 1 (tb1), possibly works independently of the branching inhibitor pathway.