The plant-specific protein FEHLSTART controls male meiotic entry, initializing meiotic synchronization in Arabidopsis
The plant-specific protein FEHLSTART controls male meiotic entry, initializing meiotic synchronization in Arabidopsis
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DOI：
10.1111/tpj.13026
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发表时间：
2015-11-01
期刊：
影响因子：
7.2
通讯作者：
Chen, Changbin
中科院分区：
文献类型：
--
作者：
Li, Junhua;Dukowic-Schulze, Stefanie;Chen, Changbin
减数分裂标志着开花植物生活史中从孢子体到配子体发生的转变，并通过同源重组产生遗传变异。在大多数开花植物中，每个花药内的减数分裂是高度同步的，这对于高效受精具有重要意义。到目前为止，人们对进入减数分裂和退出减数分裂的分子机制知之甚少，只有少数基因在拟南芥中具有调控减数分裂进程的作用。在这项研究中，我们报告了植物特异性碱性螺旋-环-螺旋（bHLH）蛋白FEHLSTART（FST）的功能特性，FEHLSTART（FST）是一种缺陷，导致减数分裂提前进入和不同步减数分裂，并导致种子产量下降。减数分裂的时间进程的调查表明，细线期的开始，前期第一阶段，往往发生在fst-1早于野生型。随后发生不同步减数分裂，这可能表现在减数分裂I/II转换期间fst-1突变体中规则的纺锤体结构和对称的细胞分裂被破坏。根据频繁加速减数分裂进入，fst-1花药减数分裂全转录组分析显示，19个昼夜节律基因受到影响，47个花粉相关基因提前表达。综上所述，我们认为FST是正常减数分裂进入和减数分裂同步建立所必需的。
Meiosis marks the transition from the sporophyte to the gametophyte generation in the life cycle of flowering plants, and creates genetic variations through homologous recombination. In most flowering plants, meiosis is highly synchronized within each anther, which is significant for efficient fertilization. To date, little is known about the molecular mechanisms of entry into meiosis and exit from it, and only a few genes in Arabidopsis have been characterized with a role in regulating meiotic progression. In this study, we report the functional characterization of a plant-specific basic helix-loop-helix (bHLH) protein, FEHLSTART (FST), a defect in which leads to premature meiotic entry and asynchronous meiosis, and results in decreased seed yield. Investigation of the time course of meiosis showed that the onset of leptotene, the first stage of prophase I, frequently occurred earlier in fst-1 than in the wild type. Asynchronous meiosis followed, which could manifest in the disruption of regular spindle structures and symmetric cell divisions in fst-1 mutants during the meiosis I/II transition. In accordance with frequently accelerated meiotic entry, whole-transcriptome analysis of fst-1 anthers undergoing meiosis revealed that 19 circadian rhythm genes were affected and 47 pollen-related genes were prematurely expressed at a higher level. Taken together, we propose that FST is required for normal meiotic entry and the establishment of meiotic synchrony.