Arabidopsis REGULATOR OF AXILLARY MERISTEMS1 controls a leaf axil stem cell niche and modulates vegetative development
Arabidopsis REGULATOR OF AXILLARY MERISTEMS1 controls a leaf axil stem cell niche and modulates vegetative development
复制标题
DOI：
10.1105/tpc.105.038588
复制
发表时间：
2006-03-01
期刊：
影响因子：
11.6
通讯作者：
Doerner, P
中科院分区：
文献类型：
--
作者：
Keller, T;Abbott, J;Doerner, P
枝梢分枝是决定植株高度变异的主要因素。形成次生生长轴的分枝起源于叶腋中被激活的干细胞。腋生分生组织（AM）和其干细胞组织的初始步骤仍然知之甚少。我们在拟南芥的调节器腋生分生组织1（RAX1）基因座上鉴定了获得和丧失功能的等位基因。RAX1由Myb样转录因子MYB37编码，并且是番茄（Solanum lycopersicum）Blind基因的拟南芥同源物。RAX1在叶原基发育早期的茎尖分生组织和叶原基之间的边界区域内的一个小的中央区域瞬时表达。RAX1与杯形子叶（CUC）基因相互作用，是CUC 2在RAX1表达结构域中表达所必需的，表明RAX1通过CUC 2起作用。我们建议RAX1的功能，以定位指定一个干细胞龛AM的形成。RAX1还通过负调节茎尖中的赤霉酸水平来影响发育阶段转换的时间。RAX1因此定义了一种新的活性，其将AM形成的规范与通过发育阶段的进展速率的调节联系起来。
Shoot branching is a major determinant of variation in plant stature. Branches, which form secondary growth axes, originate from stem cells activated in leaf axils. The initial steps by which axillary meristems (AMs) are specified and their stem cells organized are still poorly understood. We identified gain- and loss-of-function alleles at the Arabidopsis thaliana REGULATOR OF AXILLARY MERISTEMS1 (RAX1) locus. RAX1 is encoded by the Myb-like transcription factor MYB37 and is an Arabidopsis homolog of the tomato ( Solanum lycopersicum) Blind gene. RAX1 is transiently expressed in a small central domain within the boundary zone separating shoot apical meristem and leaf primordia early in leaf primordium development. RAX1 genetically interacts with CUP-SHAPED COTYLEDON (CUC) genes and is required for the expression of CUC2 in the RAX1 expression domain, suggesting that RAX1 acts through CUC2. We propose that RAX1 functions to positionally specify a stem cell niche for AM formation. RAX1 also affects the timing of developmental phase transitions by negatively regulating gibberellic acid levels in the shoot apex. RAX1 thus defines a novel activity that links the specification of AM formation with the modulation of the rate of progression through developmental phases.