Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, China.
Laboratory of Plant Molecular Genetics & Crop Gene Editing, School of Life Sciences, Linyi University, Linyi, China.
Plant Biol (Stuttg). 2021 May;23 Suppl 1:58-68. doi: 10.1111/plb.13218. Epub 2021 Jan 26.
Abiotic stresses are major environmental factors inhibiting plant growth and development. AITRs (ABA-induced transcription repressors) are a novel family of transcription factors regulating ABA (abscisic acid) signalling and plant responses to abiotic stresses in Arabidopsis. However, the composition and evolution history of AITRs and their roles in the cotton genus are largely unknown. A total of 12 putative AITRs genes were identified in cultivated tetraploid cotton, Gossypium hirsutum. Phylogenetic analysis of GhAITRs in these tetraploid cottons and their closely related species implicate ancient genome-wide duplication occurring after speciation of Gossypium, and Theobroma could generate duplicates of GhAITRs. Duplicated GhAITRs were stably inherited following diploid speciation and further allotetraploidy in Gossypium. Homologous GhAITRs shared common expression patterns in response to ABA, drought and salinity treatments, and drought tolerance induced in transgenic Arabidopsis plants expressing GhAITR-A1. Together, our findings reveal that duplicates in the GhAITRs gene family were achieved by whole genome duplication rather than three individual duplication events, and that GhAITRs function as transcription repressors and are involved in the regulation of plant responses to ABA and drought stress. These results provide insights towards the improvement of abiotic stress tolerance in cotton using GhAITRs.
非生物胁迫是抑制植物生长和发育的主要环境因素。AITR（ABA 诱导的转录阻遏物）是一类新的转录因子家族，调节 ABA（脱落酸）信号和植物对拟南芥非生物胁迫的反应。然而，AITR 的组成和进化历史及其在棉花属中的作用在很大程度上是未知的。在栽培四倍体棉花，Gossypium hirsutum 中鉴定出了 12 个假定的 AITR 基因。这些四倍体棉花及其近缘种的 GhAITRs 的系统发育分析表明，在 Gossypium 物种形成后发生了古老的全基因组复制，可可可能产生 GhAITRs 的重复。GhAITRs 的重复在二倍体物种形成后和 Gossypium 中的进一步异源四倍体化中稳定遗传。同源 GhAITRs 在响应 ABA、干旱和盐胁迫以及表达 GhAITR-A1 的转基因拟南芥植物中诱导的耐旱性方面表现出共同的表达模式。总之，我们的研究结果表明，GhAITRs 基因家族的重复是通过全基因组复制而不是三次独立的复制事件产生的，并且 GhAITRs 作为转录阻遏物起作用，并参与调节植物对 ABA 和干旱胁迫的反应。这些结果为利用 GhAITRs 提高棉花的非生物胁迫耐受性提供了新的思路。
