Blind homologous R2R3 Myb genes control the pattern of lateral meristem initiation in Arabidopsis
Blind homologous R2R3 Myb genes control the pattern of lateral meristem initiation in Arabidopsis
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DOI：
10.1105/tpc.105.038745
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发表时间：
2006-03-01
期刊：
影响因子：
11.6
通讯作者：
Theres, K
中科院分区：
文献类型：
--
作者：
Müller, D;Schmitz, G;Theres, K
在种子植物中，芽分枝是在胚后发育期间通过次生分生组织的形成而开始的。这些新的分生组织在茎原基和叶原基之间建立，发育成营养枝或花。因此，腋生分生组织的数量对植物的结构和繁殖成功有着重要的影响。本研究描述了一组由三个R2 R3 Myb基因控制的拟南芥腋生分生组织形成的遗传控制，这三个基因与番茄（Solanum lycopersicum）Blind基因同源，被命名为腋生分生组织调节子（RAX）。rax突变体表现出新的表型，其特征在于沿着茎轴的重叠区域中侧芽形成的缺陷。RAX基因在功能上是部分冗余的，并且允许对第二轴形成进行微调。通过监测茎无分生组织转录物的积累，RAX基因控制着腋生分生组织起始的非常早期的步骤。RAX 1和RAX 3表达结构域特异性地标记叶腋中心的细胞群，腋生分生组织从叶腋中心发育。侧向抑制基因和rax 1 -3的双突变体组合以及表达研究表明，至少有两条途径控制拟南芥腋生分生组织的起始。
In seed plants, shoot branching is initiated during postembryonic development by the formation of secondary meristems. These new meristems, which are established between the stem and leaf primordia, develop into vegetative branches or flowers. Thus, the number of axillary meristems has a major impact on plant architecture and reproductive success. This study describes the genetic control of axillary meristem formation in Arabidopsis thaliana by a group of three R2R3 Myb genes, which are homologous to the tomato (Solanum lycopersicum) Blind gene and were designated REGULATORS OF AXILLARY MERISTEMS (RAX). rax mutants show new phenotypes that are characterized by defects in lateral bud formation in overlapping zones along the shoot axis. RAX genes are partially redundant in function and allow a fine-tuning of secondary axis formation. As revealed by monitoring of SHOOT MERISTEMLESS transcript accumulation, the RAX genes control a very early step of axillary meristem initiation. The RAX1 and RAX3 expression domains specifically mark a cell group in the center of the leaf axil from which the axillary meristem develops. Double mutant combinations of lateral suppressor and rax1-3 as well as expression studies suggest that at least two pathways control the initiation of axillary meristems in Arabidopsis.