AP2/ERF transcription factors regulate salt-induced chloroplast division in the moss Physcomitrella patens
AP2/ERF transcription factors regulate salt-induced chloroplast division in the moss Physcomitrella patens
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DOI：
10.1007/s10265-020-01195-y
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发表时间：
2020-04-20
影响因子：
2.8
通讯作者：
Fujita, Tomomichi
中科院分区：
文献类型：
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作者：
Do, Thi Huong;Pongthai, Prapaporn;Fujita, Tomomichi
叶绿体分裂是维持植物细胞中适当叶绿体数量的关键过程。已知在一些植物物种和细胞类型中，环境胁迫会影响叶绿体分裂、分化和形态，然而这些过程的重要性和调控机制在很大程度上是未知的。在此，我们研究了盐胁迫诱导的苔藓小立碗藓（Physcomitrella patens）原丝体细胞中叶绿体分裂的调控，发现盐胁迫作为主要的非生物胁迫之一，诱导了叶绿体分裂并导致叶绿体数量增加。我们进一步鉴定出三个APETALA2/乙烯响应因子（AP2/ERF）转录因子（TFs）负责这种调控。这些AP2/ERF基因在盐胁迫下上调，氨基酸序列和系统发育分析表明，所有转录因子都只有一个保守的AP2结构域，可能属于AP2/ERF超家族中ERF - B3的同一个亚组。即使在没有NaCl胁迫的情况下，这些转录因子的过表达也显著增加了叶绿体数量。相反，这些转录因子的显性抑制形式的诱导过表达抑制了盐胁迫诱导的叶绿体分裂。因此，我们的结果表明，盐胁迫诱导的叶绿体分裂是通过AP2/ERF转录因子超家族的成员来调控的。
Chloroplast division is a critical process for the maintenance of appropriate chloroplast number in plant cells. It is known that in some plant species and cell types, environmental stresses can affect chloroplast division, differentiation and morphology, however the significance and regulation of these processes are largely unknown. Here we investigated the regulation of salt stress-induced chloroplast division in protonemal cells of the moss, Physcomitrella patens, and found that, salt stress as one of the major abiotic stresses, induced chloroplast division and resulted in increased chloroplast numbers. We further identified three APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors (TFs) that were responsible for this regulation. These AP2/ERF genes were up-regulated under salt stress, and amino acid sequences and phylogenetic analyses indicated that all TFs possess only one conserved AP2 domain and likely belong to the same subgroup of ERF-B3 in the AP2/ERF superfamily. Overexpression of these TFs significantly increased the chloroplast number even in the absence of NaCl stress. On the contrary, inducible overexpression of the dominant repressor form of these TFs suppressed salt stress-induced chloroplast division. Thus, our results suggest that salt stress induced-chloroplast division is regulated through members of the AP2/ERF TF superfamily.