LMI1 homeodomain protein regulates organ proportions by spatial modulation of endoreduplication

First author: Francesco Vuolo; Affiliations: Max Planck Institute for Plant Breeding Research (普朗克植物育种研究所): Cologne, Germany

Corresponding author: Miltos Tsiantis

How the interplay (相互作用) between cell- and tissue-level processes produces correctly proportioned organs is a key problem in biology. In plants, the relative size of leaves compared with their lateral appendages (附属器官), called stipules (托叶), varies tremendously throughout development and evolution, yet relevant mechanisms remain unknown. Here we use genetics, live imaging, and modeling to show that in Arabidopsis leaves, the LATE MERISTEM IDENTITY1 (LMI1) homeodomain protein regulates stipule proportions via an endoreduplication-dependent (核内复制) trade-off that limits tissue size despite increasing cell growth. LM1 acts through directly activating the conserved mitosis (有丝分裂) blocker WEE1, which is sufficient to bypass the LMI1 requirement for leaf proportionality.

细胞及组织层面的相互作用对于生物形成匀称的器官是十分重要的。在植物中，叶片与其侧生的附属器官，即托叶之间大小的比例关系在发育和演化过程中变异极大，并且底层的分子机制还不清楚。本文通过遗传学、活体成像及数学建模显示拟南芥的叶片LMI1同源结构域蛋白通过协调一个依赖于核內复制的组织大小和细胞生长之间的平衡来调控托叶的比例。LM1通过直接激活保守的有丝分裂抑制基因WEE1而发挥作用，这对于LMI1作用于叶片匀称是重要的。

doi: 10.1101/gad.318212.118

Journal: Genes & Development

Published in advance: 26 October, 2018

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