Antagonistic Interaction of BLADE- ON-PETIOLE1 and 2 with BREVIPEDICELLUS and PENNYWISE Regulates Arabidopsis Inflorescence Architecture
Antagonistic Interaction of BLADE- ON-PETIOLE1 and 2 with BREVIPEDICELLUS and PENNYWISE Regulates Arabidopsis Inflorescence Architecture
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DOI：
10.1104/pp.111.188573
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发表时间：
2012-02-01
期刊：
影响因子：
7.4
通讯作者：
Hepworth, Shelley R.
中科院分区：
文献类型：
--
作者：
Khan, Madiha;Xu, Mingli;Hepworth, Shelley R.
包括拟南芥（Arabidopsis thaliana）在内的许多植物物种向开花的转变，其特征是节间伸长形成花序，侧枝和花朵以一种特定的模式排列在花序上。花序的模式形成部分依赖于两种三氨基酸环延伸同源结构域转录因子的活性：短柄（BREVIPEDICELLUS，BP）和小精灵（PENNYWISE，PNY），它们相互作用的产物也促进分生组织的功能。在此我们研究了在花转变时在茎中表达上调的BP - PNY与侧生器官边界基因叶柄上着生叶片1（BLADE - ON - PETIOLE1，BOP1）和BOP2之间的遗传相互作用，BOP1和BOP2的表达局限于花梗腋部。我们的数据表明，bp和pny的花序缺陷是由茎和花梗中BOP1/2的功能获得所导致的。与此相符的是，BOP1/2的失活挽救了这些缺陷。在bp和pny突变体中，BOP的表达区域有差异地扩大，这与这些突变体中导致节间紧凑以及果实簇生或向下生长的独特生长限制模式相对应。我们的数据表明，BOP1/2是拟南芥结瘤蛋白1 - 类似物6（KNOTTED1 - LIKE FROM ARABIDOPSIS THALIANA6）表达的正调控因子，并且BOP1/2功能获得植株中的生长限制需要拟南芥结瘤蛋白1 - 类似物6。BOP1/2和BP之间的拮抗作用部分是由它们对基因表达的相互调节所解释的，这通过鉴定在茎中被BP抑制且被BOP1/2激活的木质素生物合成基因得以证明。这些数据揭示了BOP1/2的功能获得是bp和pny花序缺陷的基础，并揭示了BOP1/2和BP - PNY之间的拮抗作用如何有助于一种模式植物物种的花序模式形成。
The transition to flowering in many plant species, including Arabidopsis (Arabidopsis thaliana), is marked by the elongation of internodes to make an inflorescence upon which lateral branches and flowers are arranged in a characteristic pattern. Inflorescence patterning relies in part on the activities of two three-amino-acid loop-extension homeodomain transcription factors: BREVIPEDICELLUS (BP) and PENNYWISE (PNY) whose interacting products also promote meristem function. We examine here the genetic interactions between BP-PNY whose expression is up-regulated in stems at the floral transition, and the lateral organ boundary genes BLADE-ON-PETIOLE1 (BOP1) and BOP2, whose expression is restricted to pedicel axils. Our data show that bp and pny inflorescence defects are caused by BOP1/2 gain of function in stems and pedicels. Compatible with this, inactivation of BOP1/2 rescues these defects. BOP expression domains are differentially enlarged in bp and pny mutants, corresponding to the distinctive patterns of growth restriction in these mutants leading to compacted internodes and clustered or downward-oriented fruits. Our data indicate that BOP1/2 are positive regulators of KNOTTED1-LIKE FROM ARABIDOPSIS THALIANA6 expression and that growth restriction in BOP1/2 gain-of-function plants requires KNOTTED1-LIKE FROM ARABIDOPSIS THALIANA6. Antagonism between BOP1/2 and BP is explained in part by their reciprocal regulation of gene expression, as evidenced by the identification of lignin biosynthetic genes that are repressed by BP and activated by BOP1/2 in stems. These data reveal BOP1/2 gain of function as the basis of bp and pny inflorescence defects and reveal how antagonism between BOP1/2 and BP-PNY contributes to inflorescence patterning in a model plant species.