Study On Physiological Function Of A Rice Pleitropic Gene OsCPR5in Transgenic Arabidopisis

The plant is frequently subject to environmental stress in the growth, and drought andsalt stresses are the primary factors. These stresses can inhibit plant growth, and are oftenresponsible for low yield and poor quality of plant. The previous reports indicated thatAtCPR5is a disease-resistant gene with pleiotropic functions. We obtained a highly similargene through homologous comparison of AtCPR5and rice geneome, named OsCPR5. Ourfrontal study predicted the potential functions of OsCPR5gene by bioinformation, thenamplified OsCPR5gene and its promoter and constructed expression vectors. Its functionalroles were studied in transgenic Arabidopsis. Purpose of this paper is to understand whetherthe OsCPR5is a pleiotropic gene and the stress-responsive mechanism in transgenicArabidopsis. The main results were as follows:（1）Construction of fluorescence expression vector and acquisition of transgenicNicotiana: OsCPR5cDNA was amplified and inserted into the binary vector of pBEGFPwhich contained the35S promoter of cauliflower mosaic virus and green fluorescent protein.Then, the recombination plasmid was introduced into Nicotiana byAgrobacteandrium-mediated transformation.35S-OsCPR5transgenic tobacco was obtainedby kanamycin and Carbenicillin screening. OsCPR5mainly expressed in cell nucleus andcytomembrance by confocal microscopy scanning apical cell of transgenic tobacco.(2) Recombinant plasmid pCanG-35S-OsCPR5was introduced into wild-type ofArabidopsis and mutant of AtCPR5(atcpr5) by Agrobacterium tumefactions using floral dipmethod.35S-OsCPR5transgenic plants were obtained by kanamycin screening and PCRanalysis. Homozygores of single-copy OsCPR5were finally achieved.(3) The phenotype of over-expression and conplementary plants was not different fromcorresponding WT and atcpr5mutant through comparison, revealing that OsCPR5counldn’tcomplement functions of AtCPR5in phenotype. Analysis of germination, cptyledon greening,elongation of primary root and hypocotyl illuminated that OsCPR5gene improved toleranceof transgenic plants under ABA, NaCl and sucrose stress.(4) Elongation of primary root in over-expression and complementary plant wasobviously distinct from that of WT and atcpr5mutant under exogenous MeJA. Compared tocontol plants, enlongation of primary root in transgenic plants was more seriously inhibited.These results indicated that OsCPR5gene participated in inhibition of MeJA, wtich might berelated to JA signaling.We concluded that OsCPR5gene improved tolerance to ABA, high-salt and sucrose and involved in seed germination, cotyledon greening, primary root in transgenic Arabidopsisthaliana, which was similar to AtCPR5. OsCPR5gene restained elongation of primary rootwith MeJA. And we inferred that OsCPR5gene cooperating with AtCPR5gene responsed toMeJA in over-expression Arabidopsis thaliana.