Cloning and functional analysis of an exonuclease response gene GhWRN in cotton (Gossypium hirsutum L.)
DATE：28 September 2021 SOURCE：棉花學報
[Objective] The purpose of this study was to explore the function of GhWRN in the growth and development of cotton. [Methods] GhWRN was analyzed in aspects of gene structure, evolutionary relationship, and gene promoter features through bioinformatic methods. Its expression patterns among different cultivars, tissues, and hormone conditions were gained via quantitative real-time polymerase chain reaction (qRT-PCR). The phenotype of Arabidopsis thaliana with overexpressed GhWRN was observed. The expression pattern of marker genes involved in A. thaliana flowering signal pathway was detected by qRT-PCR. [Results] The GhWRN gene was successfully cloned according to the reference genome of upland cotton. Bioinformatic analysis showed this gene contained a conserved WRN-exo domain, without intron or transmembrane structure, and was not a secretory protein. qRT-PCR showed GhWRN was up-regulated at the second leaf stage in early-maturing cotton cultivars and was expressed in all tissues, especially in stamens and bracts. It was significantly up-regulated at 0.5 h after treatment with exogenous ABA and IAA. The transgenic A. thaliana lines showed early flowering time and decreasing rosettes number compared with the wild-type. The qRT-PCR analysis in A. thaliana indicated that GhWRN could up-regulate the expression of key genes related to flower development, i.e., AtSOC1, AtFT, and AtFUL. [Conclusion] GhWRN could promote plant flowering, which sheds light on further exploration of flowering mechanism in cotton.