State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China.
Sindh Agriculture University Tandojam, Hyderabad, Sindh, 70060, Pakistan.
BMC Plant Biol. 2021 Jan 11;21(1):37. doi: 10.1186/s12870-020-02786-6.
O-methyltransferases (OMTs) are an important group of enzymes that catalyze the transfer of a methyl group from S-adenosyl-L-methionine to their acceptor substrates. OMTs are divided into several groups according to their structural features. In Gossypium species, they are involved in phenolics and flavonoid pathways. Phenolics defend the cellulose fiber from dreadful external conditions of biotic and abiotic stresses, promoting strength and growth of plant cell wall.
An OMT gene family, containing a total of 192 members, has been identified and characterized in three main Gossypium species, G. hirsutum, G. arboreum and G. raimondii. Cis-regulatory elements analysis suggested important roles of OMT genes in growth, development, and defense against stresses. Transcriptome data of different fiber developmental stages in Chromosome Substitution Segment Lines (CSSLs), Recombination Inbred Lines (RILs) with excellent fiber quality, and standard genetic cotton cultivar TM-1 demonstrate that up-regulation of OMT genes at different fiber developmental stages, and abiotic stress treatments have some significant correlations with fiber quality formation, and with salt stress response. Quantitative RT-PCR results revealed that GhOMT10_Dt and GhOMT70_At genes had a specific expression in response to salt stress while GhOMT49_At, GhOMT49_Dt, and GhOMT48_At in fiber elongation and secondary cell wall stages.
Our results indicate that O-methyltransferase genes have multi-responses to salt stress and fiber development in Gossypium species and that they may contribute to salt tolerance or fiber quality formation in Gossypium.
O-甲基转移酶（OMTs）是一类重要的酶，能够催化 S-腺苷-L-甲硫氨酸上的甲基转移到其受体底物上。根据结构特征，OMTs 可分为几个组。在棉属物种中，它们参与酚类和类黄酮途径。酚类物质保护纤维素纤维免受生物和非生物胁迫的恶劣外部条件，促进植物细胞壁的强度和生长。
在三个主要的棉属物种，即陆地棉、亚洲棉和雷蒙德氏棉中，共鉴定和描述了一个包含 192 个成员的 OMT 基因家族。顺式调控元件分析表明，OMT 基因在生长、发育和应对胁迫方面发挥着重要作用。不同纤维发育阶段的转录组数据，包括染色体替代片段系（CSSLs）、纤维品质优良的重组自交系（RILs）和标准遗传棉花品种 TM-1，表明 OMT 基因在不同纤维发育阶段的上调，以及非生物胁迫处理与纤维品质形成和盐胁迫反应有一定的显著相关性。定量 RT-PCR 结果表明，GhOMT10_Dt 和 GhOMT70_At 基因在盐胁迫下具有特异性表达，而 GhOMT49_At、GhOMT49_Dt 和 GhOMT48_At 基因在纤维伸长和次生细胞壁阶段表达。
我们的结果表明，O-甲基转移酶基因在棉属物种中对盐胁迫和纤维发育有多种反应，它们可能有助于棉属植物的耐盐性或纤维品质形成。
