Control of dissected leaf morphology by a Cys(2)His(2) zinc finger transcription factor in the model legume Medicago truncatula
Control of dissected leaf morphology by a Cys(2)His(2) zinc finger transcription factor in the model legume Medicago truncatula
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DOI：
10.1073/pnas.1003954107
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发表时间：
2010-06-08
影响因子：
11.1
通讯作者：
Chen, Rujin
中科院分区：
文献类型：
--
作者：
Chen, Jianghua;Yu, Jianbin;Chen, Rujin
植物叶片形态多样，在很大程度上反映了自然环境中植物的多样性。不同的叶子形态是如何确定的还不清楚。豆科植物紫花苜蓿（Medicago truncatula）的叶片解剖，顶端有三片小叶。我们发现三叶叶的发育是由Cys(2)His(2)锌指转录因子PALM1决定的。PALM1的功能缺失突变体发育出裂叶，叶尖处聚集有5个小叶。我们发现PALM1结合了一个特定的启动子序列，并下调了M. truncatula LEAFY/UNIFOLIATA同源基因SINGLE LEAFLET1 （SGL1）的表达，该基因编码了小叶起始所需的一个不确定因子。我们的数据表明SGL1是棕榈突变体小叶增殖所必需的。有趣的是，在拟南芥植物中，PALM1的异位表达有效地抑制了1类knotted1样同源盒蛋白的过表达引起的叶裂表型。综上所述，我们的研究结果表明，PALM1作为一个决定性因子，调控了SGL1在叶片形态发生过程中的时空表达，并与LEAFY/UNIFOLIATA同源基因一起，在协调柽柳复叶形态中发挥了重要作用。
Plant leaves are diverse in their morphology, reflecting to a large degree the plant diversity in the natural environment. How different leaf morphology is determined is not yet understood. The leguminous plant Medicago truncatula exhibits dissected leaves with three leaflets at the tip. We show that development of the trifoliate leaves is determined by the Cys(2)His(2) zinc finger transcription factor PALM1. Loss-of-function mutants of PALM1 develop dissected leaves with five leaflets clustered at the tip. We demonstrate that PALM1 binds a specific promoter sequence and down-regulates the expression of the M. truncatula LEAFY/UNIFOLIATA orthologue SINGLE LEAFLET1 (SGL1), encoding an indeterminacy factor necessary for leaflet initiation. Our data indicate that SGL1 is required for leaflet proliferation in the palm1 mutant. Interestingly, ectopic expression of PALM1 effectively suppresses the lobed leaf phenotype from overexpression of a class 1 KNOTTED1-like homeobox protein in Arabidopsis plants. Taken together, our results show that PALM1 acts as a determinacy factor, regulates the spatial-temporal expression of SGL1 during leaf morphogenesis and together with the LEAFY/UNIFOLIATA orthologue plays an important role in orchestrating the compound leaf morphology in M. truncatula.