Expression Characterization Of Rice OsMPK17 Protein And Its Function Investigation In The Response Process To Drought Stress

Rice is the most important food crop and model organism for basic research.Rice is subjected to various biotic and abiotic stresses throughout its life cycle,and in order to cope with the stress caused by environmental change,rice itself has developed mechanisms to resist adversity.The mitogen-activated protein kinase belongs to eukaryotic protein kinase superfamily,and MAPK gene in the cascade pathway plays a crucial role in the process of resisting process.The expression characteristics and function of OsMPK17 protein under stress have not been reported.In this study,specific antibody against rice OsMPK17 protein was used to detect the expression patterns of OsMPK17 protein at different stages and sites of normal rice growth and development,and under different stress and hormone treatment conditions by Western blot.The OsMPK17 transgenic rice was detected by PCR and WB technique.The homozygous overexpressed transgenic plants were screened and identified,andthe phenotypes and agronomic characters of OsMPK17 transgenic rice were investigated such as plant height,tiller number,panicle length and seed setting rate.The results lay the foundation for further study on the function of OsMPK17 in the process of stress tolerance in rice(Oryza sativa L.).The main results and conclusions were summarized as follows:1.WB and transcriptional data analysis showed that OsMPK17 was mainly expressed in leaves and anthers,the experiment showed that the transcription and expression of OsMPK17 gene in rice were tissue-specific during normal growth and development.2.The changes of OsMPK17 protein expression in abiotic stress were investigated by Western blot.It was found that the expression of OsMPK17 protein was up-regulated under drought stress,but no significant changes under cold,heat,constant light and constant dark treatment.During hormone treatment by ABA and MeJA,the investigation found that the expression of OsMPK17 protein were decreased,but there was no obvious changes under the treatment of hormone SA and ET.These data suggest that it plays a role in drought stress and hormone-mediated pathways.3.Positive transgenic plants were identified by PCR technique.Western blot analysis showed that OsMPK17 protein was overexpressed.It is proved that the positive homozygous individuals of transgenic materials have been obtained.4.The agronomic investigation found that the OsMPK17 overexpression transgenic plants showed shorter plant height,lower seed setting rate and panicle length than that the wild type,suggested that the overexpression of OsMPK17 affects the plant type and grain development of rice(Oryza sativa L.).5.During germination stage,the OsMPK17 overexpression seeds grew significantly stronger than that the wild-type seeds,and the root and shoot length were longer than that the wild-type seeds.In the experiment of soil culture or restoration watering under drought stress at seedling stage,it was found that the growth of OsMPK17 overexpressed transgenic plants was stronger than that of wild-type.Overexpression of OsMPK17 protein improved the drought tolerance of rice.