Abstract:

This study is to dissect Gossypium hirsutu’s small GTP-binding protein gene GhROP3 expression patterns responding to different abiotic stresses,thus providing a foundation for stress-related genes cloning and elucidating the molecular mechanism of G. hirsutu stress-resistance. Homologous approach was used to clone the GhROP3,and bioinformatics methods were employed to analyze the physical and chemical properties of the gene. qRT-PCR was to investigate the tissue-specific expressions and patterns of GhROP3 under various induction conditions. The VIGS silencing vector of the gene was constructed and transformed into cotton by Agrobacterium-mediated method,and the silencing efficiency was detected by qRT-PCR. As results,the GhROP3 was cloned from the cDNA of G. hirsutu,it contained a 591 bp open reading frame,encoded a basic and hydrophilic protein containing 196 amino acid residues,the relative molecular mass was 21.75 kD. qRT-PCR analysis showed that GhROP3 expressed in the roots,stems,leaves,cotyledons and hypocotyl of G. hirsutu seedlings,and especially at a relatively higher level in stems. GhROP3 expression responded differentially to high salinity,drought,low temperature and Verticillium wilt. The VIGS silencing vector of the gene was constructed and transformed into cotton. The silenced GhROP3 in the leaves and roots of cotton was detected by qRT-PCR,which proved that the VIGS silencing vector was successfully constructed and worked normally in plants. The results suggested that GhROP3 may play important roles in the adversity stress adaption of G. hirsutu plant.

Key words: cotton, GhROP3, gene cloning, expression analysis, vector construction