Distinct expression patterns of the GDP dissociation inhibitor protein gene (OsRhoGDI2) from Oryza sativa during development and abiotic stresses

Guanine nucleotide dissociation inhibitor (GDI) plays an essential role in regulating the forms of Rac/Rop between GDP-bound inactivity and GTP-bound activity in plants. In this paper, we reported a stress-responsive GDI gene (OsRhoGDI2) from rice (Oryza sativa L.). We analyzed the transcript levels of OsRhoGDI2 gene in various tissues, organs, and developmental stages to obtain information about its function. We further researched the expression patterns of OsRhoGDI2 gene in response to abiotic stress signals. qRT-PCR demonstrated that OsRhoGDI2 was distinctly expressed in various plant tissues and organs at different levels. The expression of OsRhoGDI2 was also highly salty and drought inducible, it also moderately responded to Methyl Jasmonate (MeJA), abscisic acid (ABA), and Indole-3-acetic Acid (IAA), treatment but was only slightly affected by 6-Benzylaminopurine (6-BA) and salicylic acid (SA) treatments. Nevertheless, reduced expression conferred hypersensitivity to gibberellin (GA) stress in rice. The promoter of OsRhoGDI2 gene was used to drive β-glucuronidase (GUS) gene expression. Results of GUS histochemical staining showed the tissue-specific expression patterns of OsRhoGDI2, and GUS gene expression in two-week-old transgenic rice seedling exhibited relatively similar patterns under different stresses of the transgenic rice lines. These results provided insights into the characteristics and roles of the OsRhoGDI2 gene during development and strongly suggested that OsRhoGDI2 may play direct or indirect roles in the tolerance to different stresses in rice and may serve as a basis for further functional studies.