Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
Physiol Plant. 2021 Nov;173(3):1078-1089. doi: 10.1111/ppl.13505. Epub 2021 Aug 5.
N -methyladenosine (m A) is an abundant methylation mark in eukaryotic mRNAs. It is installed and removed by methyltransferases ("writers") and demethylases ("erasers"), respectively. A recent study has demonstrated that alpha-ketoglutarate-dependent dioxygenase homolog 10B (ALKBH10B) is an mRNA m A eraser affecting floral transition in Arabidopsis thaliana. However, the roles of m A eraser proteins, including ALKHB10B, in plant adaptation to abiotic stresses are largely unknown. In this study, we aimed to determine the role of ALKBH10B in the response of A. thaliana to abiotic stresses and abscisic acid (ABA). The m A level increased in response to salt stress, and m A levels in alkbh10b mutants were higher than those in the wild-type under both normal and salt stress conditions. Germination of alkbh10b mutant seeds was markedly delayed under salt stress but not under dehydration, cold, or ABA conditions. Seedling growth and survival rate of alkbh10b mutants were enhanced under salt stress. Notably, salt-tolerant phenotypes of alkbh10b mutants were correlated with decreased levels of several m A-modified genes, including ATAF1, BGLU22, and MYB73, which are negative effectors of salt stress tolerance. In response to ABA, both seedling and root growth of alkbh10b mutants were inhibited via upregulating ABA signaling-related genes, including ABI3 and ABI4. Collectively, these findings indicate that ALKBH10B-mediated m A demethylation affects the transcript levels of stress-responsive genes, which are important for seed germination, seedling growth, and survival of Arabidopsis thaliana in response to salt stress or ABA.
N6-甲基腺苷(m6A)是真核生物 mRNA 中丰富的甲基化标记。它分别由甲基转移酶(“写入器”)和去甲基化酶(“橡皮擦”)安装和去除。最近的一项研究表明,α-酮戊二酸依赖性双加氧酶同源物 10B(ALKBH10B)是一种 mRNA m6A 橡皮擦,影响拟南芥的花发育转变。然而,m6A 橡皮擦蛋白(包括 ALKBH10B)在植物适应非生物胁迫中的作用在很大程度上尚不清楚。在本研究中,我们旨在确定 ALKBH10B 在拟南芥对非生物胁迫和脱落酸(ABA)的响应中的作用。盐胁迫导致 m6A 水平升高,在正常和盐胁迫条件下,alkbh10b 突变体中的 m6A 水平均高于野生型。alkbh10b 突变体种子在盐胁迫下的萌发明显延迟,但在脱水、寒冷或 ABA 条件下则不然。alkbh10b 突变体的幼苗生长和存活率在盐胁迫下增强。值得注意的是,alkbh10b 突变体的耐盐表型与几种 m6A 修饰基因的水平降低有关,包括 ATAF1、BGLU22 和 MYB73,它们是盐胁迫耐受性的负效因子。在响应 ABA 时,alkbh10b 突变体的幼苗和根生长均通过上调 ABA 信号相关基因(包括 ABI3 和 ABI4)受到抑制。总之,这些发现表明,ALKBH10B 介导的 m6A 去甲基化影响了应激反应基因的转录水平,这对于拟南芥种子萌发、幼苗生长和在盐胁迫或 ABA 响应中的存活至关重要。