The Trihelix Transcription Factor GTL1 Regulates Ploidy-Dependent Cell Growth in the Arabidopsis Trichome
The Trihelix Transcription Factor GTL1 Regulates Ploidy-Dependent Cell Growth in the Arabidopsis Trichome
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DOI：
10.1105/tpc.109.068387
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发表时间：
2009-08-01
期刊：
影响因子：
11.6
通讯作者：
Sugimoto, Keiko
中科院分区：
文献类型：
--
作者：
Breuer, Christian;Kawamura, Ayako;Sugimoto, Keiko
拟南芥叶毛状体的发育经历了几个不同的细胞过程，如图案形成、分化和生长。虽然最近的研究已经确定了几个关键的转录因子作为调节早期的图案和分化步骤，它仍然是在很大程度上不知道这些调节蛋白如何介导随后的毛状体的发展，这是伴随着快速的细胞生长和分支。在这里，我们报告了一种新的毛状体突变拟南芥，与以前确定的突变体相比，增加毛状体细胞的大小，而不改变其整体图案或分支。我们发现，相应的基因编码GT-2-LIKE 1（GTL 1）蛋白，三螺旋转录因子家族的成员。GTL 1存在于毛状体发育的分支后阶段的细胞核内，其功能的丧失导致仅在已完成分支的毛状体中的细胞核DNA含量增加。我们的数据进一步表明，gtl 1突变修改了几个细胞周期基因的表达和部分挽救倍性缺陷的细胞周期蛋白依赖性激酶抑制剂突变体暹罗。两者合计，这项研究提供了遗传学证据的转录调控的要求，在镇压倍性依赖的植物细胞生长，以及参与GTL三螺旋蛋白在这种调节。
Leaf trichomes in Arabidopsis thaliana develop through several distinct cellular processes, such as patterning, differentiation, and growth. Although recent studies have identified several key transcription factors as regulating early patterning and differentiation steps, it is still largely unknown how these regulatory proteins mediate subsequent trichome development, which is accompanied by rapid cell growth and branching. Here, we report a novel trichome mutation in Arabidopsis, which in contrast with previously identified mutants, increases trichome cell size without altering its overall patterning or branching. We show that the corresponding gene encodes a GT-2-LIKE1 (GTL1) protein, a member of the trihelix transcription factor family. GTL1 is present within the nucleus during the postbranching stages of trichome development, and its loss of function leads to an increase in the nuclear DNA content only in trichomes that have completed branching. Our data further demonstrate that the gtl1 mutation modifies the expression of several cell cycle genes and partially rescues the ploidy defects in the cyclin-dependent kinase inhibitor mutant siamese. Taken together, this study provides the genetic evidence for the requirement of transcriptional regulation in the repression of ploidy-dependent plant cell growth as well as for an involvement of GTL trihelix proteins in this regulation.