Analyses of functional conservation and divergence reveal requirement of bHLH010/089/091 for pollen development at elevated temperature in Arabidopsis
Analyses of functional conservation and divergence reveal requirement of bHLH010/089/091 for pollen development at elevated temperature in Arabidopsis
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功能保守性和分歧分析揭示了拟南芥高温下花粉发育所需的 bHLH010/089/091
DOI：
10.1016/j.jgg.2020.09.001
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发表时间：
2020-08-01
影响因子：
5.9
通讯作者：
Chang, Fang
中科院分区：
文献类型：
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作者：
Fu, Ying;Li, Mengyu;Chang, Fang
拟南芥bHLH 010/089/091（basic helix-loop-helix）基因在功能上是冗余的，并且是花药发育和DYT 1激活的花药相关基因的正常表达所必需的。这三个基因是保守的，在菊科，这表明他们每个人都在选择压力下，然而，鲜为人知的是这些bHLH基因之间的可能的功能差异和bHLH和DYT 1基因之间。在这里，我们比较了新的花药转录组数据集bHLH 010/089/091单，双突变体，花药转录组数据集野生型（WT）和先前获得的花药转录组数据集bhlh 010 bhlh 089 bhlh 091三重突变体。结果表明，bHLH 010、bHLH 089和bHLH 091的分子表型支持它们的功能冗余和差异，以及它们与DYT 1的功能重叠和差异。DNA结合分析显示，DYT 1和bHLH 089特异性识别TCATGTGC盒，以激活靶基因的表达，包括ATA 20，EXL 4和MEE 48。此外，在bhlh 010 bhlh 089双突变体和bhlh 010 bhlh 089 bhlh 091三突变体中表达受影响的基因中，富集了参与胁迫反应和细胞信号传导的基因，其中包括256个在早期花发育期间优先受热诱导表达的基因。此外，bhlh双突变体表现出有缺陷的花粉发育时，植物生长在高温下，表明bHLH基因是重要的花药基因表达在这种条件下。这些结果与bhlh突变体中几个基因的热诱导表达低于WT中的观察结果一致。因此，我们的研究结果为DYT 1-bHLH 089异源二聚体激活直接靶点的分子机制提供了重要的见解，并证明了bHLH 010/089/091在热胁迫下维持生育力的保护作用。中国科学院遗传与发育生物学研究所版权所有（C）2020由爱思唯尔有限公司和科学出版社出版。All rights reserved.
The Arabidopsis bHLH010/089/091 (basic helix-loop-helix) genes are functionally redundant and are required for both anther development and normal expression of DYT1-activated anther-related genes. These three genes are conserved in Brassicaceae, suggesting that each of them is under selection pressure; however, little is known about the possible functional differences among these bHLH genes and between the bHLH and DYT1 genes. Here, we compared novel anther transcriptomic data sets from bHLH010/089/091 single and double mutants, with an anther transcriptomic data set from the wild type (WT) and a previously obtained anther transcriptomic data set from the bhlh010 bhlh089 bhlh091 triple mutant. The results revealed molecular phenotypes that support the functional redundancy and divergence of bHLH010, bHLH089, and bHLH091, as well as the functional overlap and difference between them and DYT1. DNA-binding analyses revealed that DYT1 and bHLH089 specifically recognize the TCATGTGC box to activate the expression of target genes, including ATA20, EXL4, and MEE48. In addition, among genes whose expression was affected in the bhlh010 bhlh089 double and bhlh010 bhlh089 bhlh091 triple mutants, genes that are involved in the stress response and cell signaling were enriched, which included 256 genes whose expression was preferentially induced by heat during early flower development. Moreover, the bhlh double mutants exhibited defective pollen development when the plants were grown under elevated temperature, suggesting that bHLH genes are important for anther gene expression under such conditions. These results are consistent with the observation that the heat-induced expression of several genes is less in the bhlh mutants than that in the WT. Therefore, our results provide important insights into the molecular mechanism underlying the activation of direct targets by DYT1-bHLH089 heterodimers and demonstrate the protective roles of bHLH010/089/091 in maintaining fertility upon heat stress. Copyright (C) 2020, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Limited and Science Press. All rights reserved.