Regulation of Arabidopsis tapetum development and function by dysfunctional tapetum1 (dyt1) encoding a putative bHLH transcription factor
Regulation of Arabidopsis tapetum development and function by dysfunctional tapetum1 (dyt1) encoding a putative bHLH transcription factor
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DOI：
10.1242/dev.02463
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发表时间：
2006-08-15
期刊：
影响因子：
4.6
通讯作者：
Ma, Hong
中科院分区：
文献类型：
--
作者：
Zhang, Wei;Sun, Yujin;Ma, Hong
在开花植物中，雄性育性取决于花药中适当的细胞分化。然而，对调控花药细胞分化和功能的基因知之甚少。在这里，我们报告了一个新的拟南芥雄性不育突变体，功能障碍tapetum1（dyt1）的分析。dyt1突变体表现出异常的花药形态开始在花药阶段4，绒毡层细胞有多余的和/或扩大的液泡，缺乏典型的正常绒毡层细胞的细胞质染色密集。突变的性母细胞能够完成减数分裂I，但它们没有厚的胼胝质壁;它们通常不能完成减数分裂胞质分裂并最终崩溃。DYT1编码一个假定的bHLH转录因子，并强烈表达在绒毡层从晚期花药阶段5至早期阶段6，并在一个较低的水平，在性母细胞。此外，DYT1 mRNA水平在无孢子细胞/喷嘴（spl/nzz）和过量小孢子细胞1/额外造孢细胞（ems1/exs）突变体中降低;连同突变表型，这表明DYT1在SPL/NZZ和EMS1/EXS下游起作用。RT-PCR结果表明，在dyt1突变体中，许多绒毡层优先基因的表达水平显著降低，表明DYT1对绒毡层基因的表达具有重要意义。我们的研究结果支持DYT1是控制花药发育和功能的遗传网络的重要组成部分的假设。
In flowering plants, male fertility depends on proper cell differentiation in the anther. However, relatively little is known about the genes that regulate anther cell differentiation and function. Here, we report the analysis of a new Arabidopsis male sterile mutant, dysfunctional tapetum1 (dyt1). The dyt1 mutant exhibits abnormal anther morphology beginning at anther stage 4, with tapetal cells that have excess and/or enlarged vacuoles and lack the densely stained cytoplasm typical of normal tapetal cells. The mutant meiocytes are able to complete meiosis I, but they do not have a thick callose wall; they often fail to complete meiotic cytokinesis and eventually collapse. DYT1 encodes a putative bHLH transcription factor and is strongly expressed in the tapetum from late anther stage 5 to early stage 6, and at a lower level in meiocytes. In addition, the level of DYT1 mRNA is reduced in the sporocyteless/nozzle (spl/nzz) and excess microsporocytes1/extra sporogenous cell (ems1/exs) mutants; together with the mutant phenotypes, this suggests that DYT1 acts downstream of SPL/NZZ and EMS1/EXS. RT-PCR results showed that the expression levels of many tapetum-preferential genes are reduced significantly in the dyt1 mutant, indicating that DYT1 is important for the expression of tapetum genes. Our results support the hypothesis that DYT1 is a crucial component of a genetic network that controls anther development and function.