Multi-responses of O-methyltransferase genes to salt stress and fiber development of Gossypium species

Abstract

AbstractBackgroundO-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. InGossypiumspecies, 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.ResultsAnOMTgene family, containing a total of 192 members, has been identified and characterized in three mainGossypiumspecies,G. hirsutum,G. arboreumandG.raimondii. Cis-regulatory elements analysis suggested important roles ofOMTgenes 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 ofOMTgenes 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 thatGhOMT10_DtandGhOMT70_Atgenes had a specific expression in response to salt stress whileGhOMT49_At,GhOMT49_Dt, andGhOMT48_Atin fiber elongation and secondary cell wall stages.ConclusionsOur results indicate that O-methyltransferase genes have multi-responses to salt stress and fiber development inGossypiumspecies and that they may contribute to salt tolerance or fiber quality formation inGossypium.