Abstract:The members of Rho family of small GTP-binding proteins isolated from plant species form a plant-specific one designated Rop (Rho-related proteins of plant）family. They play important roles in regulating plant development, stress tolerance and defense responses. In this study, a full-length cDNA encoding a Rop protein was isolated from the cDNA library of the near-isogenic line (Taichung29*6／Yr5) of wheat stripe rust resistance gene Yr5 using homologous cloning method, and it was designated TaRop2（Triticum aestivum Rop2). It contained a 591-bp open reading frame encoding a 197-amino-acid protein, whose molecular weight is about 21.52 kDa with isoeletric point (pI) 9.49. It was confirmed that TaRop2 were mainly distributed in the nuclei and on the membrane in tobacco epidermal cells through subcellular localization experiment. By RT-PCR expression analyses, TaRop2 expression level was increased after salt treatment or inoculation with incompatible race of stripe rust pathogen and compatible mixed powdery mildew strains, but was suppressed by treatments of drought, heat, cold and ABA. Based on these results, we proposed that TaRop2 may be involved in regulation of wheat development, defence and stress responses.