Abstract：Multigene family of uridine dipfosphate glycosyltransferases (UGTs), comprising the greatest number of glycosyltransferases, involve in various biological processes, such as regulation of plant growth and development, and response to abiotic stresses. In the present study, one UGT gene, named as GhUGT85O1(GenBank No. KP300000) in cotton (Gossypium hirsutum) was identified. The full length of its open reading frame (ORF) and predicted peptide chain was 1 422 bp and 473 amino acids, respectively. The C-terminal contained a plant specific putative secondary plant glycosyltransferase (PSPG) motif found in UGTs family. Quantitative Real-time PCR (qRT-PCR) result indicated that GhUGT85O1 expressed extensively in the mature and old leaves, and was induced by abscisic acid (ABA), jasmonic acid (JA) and polyethylene glycol (PEG) in cotton. To illustrate its biological function, 35S::GhUGT85O1 vector was constructed and transformed into Arabidopsis thaliana. The over expression of GhUGT85O1 in transgenic Arabidopsis thaliana showed significantly early flowering (P＜0.01) and accelerated senescence phenotype compared with that in wild type. The chlorophyll content in transgenic Arabidopsis thaliana was significantly lower than that in wild type at senescence stage(P＜0.01). Meanwhile, the expression levels of AtORE1, senescence-associated gene12 (AtSAG12), AtSAG13, WRKY DNA-binding protein 6 gene (AtWRKY6), NAC transcription factor (AtNAP) and pathogenesis-related protein 1 gene (AtPR1) of senescence associated genes were higher than that in wild type(P＜0.05 or P＜0.01). Promoter deletion analysis result located the essential region of GhUGT85O1 promoter on -1 077~-1 363 bp, which contained 3 cis-acting elements of anaerobic response element(ARE), WRKY transcription factors binding site(W box) and TGA element (TGA). The result preliminarily suggested the involvement of GhUGT85O1 in response to abiotic stresses, regulation of both flowering time and senescence. It will not only establish a solid foundation for further function identification of GhUGT85O1 in cotton, but also provide gene resources for breeding short season cotton.
