Towards Understanding OsDWD And OCPI2 In Regulating Rice Stress Responses

Rice is one of the most important food crops in the world,and its growth and development process is easily affected by drought and salt stress.Therefore,it is of great significance for developing rice varieties with improved tolerance to drought and salt stress.Two genes OsDWD and OCPI2 likely involved in rice response to abiotic stress were identified.We focused on the conservativeness of OsDWD and OCPI2 among different species,the response to external stress and various hormones,the specificity of spatio-temporal expression in rice and the function of resistance to adversity in this study.The results are as follows:1:OsDWD gene:（1）Bioinformatics analysis:the results of evolutionary tree analysis showed that OsDWD protein was highly conserved in many species,especially in animals;Promoter analysis results showed that OsDWD gene promoter contains elements such as ABRE,Box4,G-box,TCT-motif,Chs-Cmala,HD-ZIP l,P-box and T-C rich repeats,indicating that this gene may be associated with these adverdities in rice response.（2）Expression pattern analysis:semi-quantitative and quantitative results showed that OsDWD gene were induced by ABA,PEG,Na Cl,H₂O₂,SA,Me JA,light and cold stress and were expressed in roots,stems,young leaves,old leaves and shoots.（3）Phenotypic analysis:there was no significant difference in the growth status of wild-type and Osdwd mutants under normal conditions;After exogenous PEG treatment,vegetative growth period and reproductive growth period drought treatment,the survival rate of Osdwd mutants was higher and the water loss rate of Osdwd mutants in vitro was lower;After exogenous Na Cl treatment,the survival rate and chlorophyll content of Osdwd mutants were higher,NBT staining was shallower than the wild type;After ABA treatment,there was no difference in sensitivity between Osdwd mutants and wild-type mutants.2:OCPI2 gene:（1）Bioinformatics analysis:the results of evolutionary tree analysis showed that OCPI2 gene was highly conserved between its gene family and different species;OCPI2 gene promoters contained elements such as ABRE,G-box,Box-4,GT1-motif,I-box,MRE,LTR,CGTCA-motif and TCA-element,indicating that OCPI2 gene may be involved in rice response to these stresses.（2）Expression pattern analysis:semi-quantitative and quantitative analysis showed that OCPI2 gene was induced by exogenous ABA,Na Cl,H₂O₂,SA,Me JA,light,darkness,cold and drought stress,and was expressed in roots,stems,old leaves,buds,young leaves and leaf sheath;Gus staining results showed that this gene was highly expressed in the young leaves.（3）Phenotypic analysis:ocpi2 mutants showed decreased sensitivity to ABA inhibition of seed germination;The expression of genes in ABA signaling pathway was up-regulated;Drought tolerance of ocpi2 mutants decreased.（4）Transgenic plants of Ubi::OCPI2-Myc have been constructed and a homozygous line has already been generated and is under investigation.