Expression Characterization Of Rice OsPR10A Protein And Its Functional Investigation In The Response To Drought Stress

Pathogenesis-related(PR)proteins are a class of pathogen-inducible proteins that play important roles in plant struggle with biotic and abiotic stresses.Rice(Oryza sativa L.)is one of the most important food crops in the world.As the staple food of nearly half of the world's population,its high yield and stable production are of great significance to the food security of the world,especially in Asia.Rice growth is often threatened by harsh environments such as cold,heat,drought,salt and submerge.There are nearly a thousand of PR genes in rice genome,and a number of studies on the function of OsPR10 A gene have been reported.It was identified previously in our laborotary that the protein was induced during the interaction between rice and Xanthomonas oryzae pv.oryzae(Xoo).At present,there are few studies on the function of OsPR10 A in abiotic stress in rice.In this study,the expression patterns of rice OsPR10 A protein were surveyed using western blot(WB)analysis for protein samples extracted from different tissues at different developmental stages and a variety of abiotic stresses.The results showed that OsPR10 A protein was not expressed before germination in seeds,and the expression level increased as the germination time extends.OsPR10 A protein was not expressed in the roots at seedling stage and expressed in roots after tillering stage.In the leaves,it is also not expressed in the seedling stage,and expressed in the leaves after tillering stage.OsPR10 A was not expressed in rice stems at tillering stage,booting stage and flowering stage.But in the rice phyllula,OsPR10 A was expressed at tillering stage and booting stage.The expression levels of OsPR10 A in spike,anther and husk at the flowering stage were higher,but not in the spike-stalk.The expression of OsPR10 A was high in young flag leaves,but as the flag leaves grow and enter the senescence period,the abundance of OsPR10 A also gradually decreases.The expression of OsPR10 A protein was induced by drought and salt stress.Under drought stress,the expression level of OsPR10 A protein increased significantly from 2 days.Under salt stress,the abundance of OsPR10 A increased from 12 hours.In vitro leaf treatment at the rice seedling stage,under different conditions of hormone,the expression of OsPR10 A increased in different degrees.In the light treatment,the expression of OsPR10 A was induced by constant light treatment.Meanwhile,the OsPR10 A overexpression vector was constructed and transformed into rice TP309 by Agrobacterium-mediated method.Transgenic plants were detected by PCR and WB techniques to obtain homozygous positive transgenic plants.Phenotypic investigation in field experiment revealed that the plant height and the spike length were shorter,meanwhile,the seed setting rate was decreased in transgenic lines compared with the wild type.Drought stress treatment was carried out using 20% PEG6000 at seed germination stage.The results showed that the root and shoot length of OsPR10 A overexpression transgenic lines were significantly higher than that of wild type.