Differential regulation of meristem size, morphology and organization by the ERECTA, CLAVATA and class III HD-ZIP pathways.
Differential regulation of meristem size, morphology and organization by the ERECTA, CLAVATA and class III HD-ZIP pathways.
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DOI：
10.1242/dev.129973
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发表时间：
2016-05-01
期刊：
影响因子：
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通讯作者：
Williams LE
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文献类型：
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作者：
Mandel T;Candela H;Landau U;Asis L;Zelinger E;Carles CC;Williams LE
被子植物的茎尖分生组织（SAM）是一个小的，高度组织化的结构，产生所有地上器官。SAM分为三个功能区域：SAM尖端的中心区（CZ）容纳自我更新的多能干细胞和组织中心，提供子细胞，这些子细胞不断地转移到内部肋骨区（RZ）或周围外周区（PZ），从那里开始器官原基。尽管细胞不断地从CZ流向RZ或PZ，并且细胞募集用于原基形成，但SAM中不同细胞群之间保持着稳定的平衡。在这里，我们将深入的表型分析与比较RNA-Seq方法相结合，从选择的拟南芥clavata3 （clv3）、jabba-1D （jba-1D）和erecta （er）突变体组合中对分生组织进行了表征。我们发现CLV3沿着顶基轴限制分生组织的扩展，而III类HD-ZIP和ER途径限制分生组织的横向扩展，但在不同的方向上，可能是垂直的。我们的k-means分析表明，clv3、jba-1D/+和er通过影响分生组织功能的不同方面导致分生组织扩大；例如，clv3在干细胞群中表现出增加，而jba-1D/+ er在有丝分裂活性和分生细胞群中表现出增加。我们的分析表明，结合遗传和mRNA-Seq比较方法提供了一种精确和敏感的方法来鉴定小结构（如SAM）中的细胞类型特异性转录组。摘要：拟南芥茎尖分生组织的大小、形态和组织平衡由三条途径共同调控。
The shoot apical meristem (SAM) of angiosperm plants is a small, highly organized structure that gives rise to all above-ground organs. The SAM is divided into three functional domains: the central zone (CZ) at the SAM tip harbors the self-renewing pluripotent stem cells and the organizing center, providing daughter cells that are continuously displaced into the interior rib zone (RZ) or the surrounding peripheral zone (PZ), from which organ primordia are initiated. Despite the constant flow of cells from the CZ into the RZ or PZ, and cell recruitment for primordium formation, a stable balance is maintained between the distinct cell populations in the SAM. Here we combined an in-depth phenotypic analysis with a comparative RNA-Seq approach to characterize meristems from selected combinations of clavata3 (clv3), jabba-1D (jba-1D) and erecta (er) mutants of Arabidopsis thaliana. We demonstrate that CLV3 restricts meristem expansion along the apical-basal axis, whereas class III HD-ZIP and ER pathways restrict meristem expansion laterally, but in distinct and possibly perpendicular orientations. Our k-means analysis reveals that clv3, jba-1D/+ and er lead to meristem enlargement by affecting different aspects of meristem function; for example, clv3 displays an increase in the stem cell population, whereas jba-1D/+ er exhibits an increase in mitotic activity and in the meristematic cell population. Our analyses demonstrate that a combined genetic and mRNA-Seq comparative approach provides a precise and sensitive method to identify cell type-specific transcriptomes in a small structure, such as the SAM. Summary: Three pathways converge to regulate the balance between meristem size, morphology and organization in the Arabidopsis shoot apical meristem.