Research On The Function Of Ricinus Communis L.Salt Tolerance Related Genes RcGST And RcDHAR

Soil salinization is one of the main abiotic stresses that affect crop growth and lead to crop yield reduction.Breeding new salt tolerant crop germplasm by genetic engineering is an effective measure to utilize and improve salt alkali land.In this study,up-regulated proteins Tau and DHAR glutathione transferase RcGST and RcDHAR were screened from the proteomic data of seed germination under salt stress,the expression profile of RcGST and RcDHAR in seedling stage of Tongbi 5 under salt stress were analyzed.RcGST and RcDHAR were cloned from Tongbi 5 and overexpressed in Arabidopsis and castor hairy roots to validate their function,Laying the foundation for studying the response of RcGST and RcDHAR in castor under salt tolerance and breeding new germplasm of salt tolerant and high yield castor.The main research results are as follows:qRT-PCR was used to analyze the expression characteristics of RcGST and RcDHAR under the salt stress in seedling stage of castor,RcGST and RcDHAR are express in the roots,stems and leaves of castor.The expression of RcGST and RcDHAR is influenced by salt stress and had different tissue expression.The highest expression of RcGST was found in castor leaves under salt stress,followed by stems and roots;the expression of RcDHAR was higher in roots,stems and lower in leaves under salt stress.Designed specific primers to clone tau and DHAR glutathione transferase,named RcGST and RcDHAR,RcGST is comprised of an open reading fram(ORF)of 672 bp and encods a protein of 223 amino acids,with the homology of more than 70%with the GST amino acids of 7 plants such as Hevea brasiliensis;RcDHAR is comprised of an ORF of 552 bp and encods a protein of 183 amino acids,with the homology of more than 83%with the DHAR amino acids of 7 plants such as Jatropha.RcGST and RcDHAR were transformed into Arabidopsis by Agrobacterium tumefaciens and castor hairy roots by Agrobacterium rhizogenes.The results showed that the germination rate of transgenic Arabidopsis seeds under salt stress was significantly higher than that of wild type,and the root length and growth state of seedlings were significantly better than that of wild type.The results of physiological indexes showed that the electrical conductivity(REL),malondialdehyde(MDA)and superoxide dismutase(SOD)activities of transgenic Arabidopsis and castor hairy root under salt stress were significantly lower than those of wild type,and the activities of SOD were significantly higher than those of wild type.Under salt stress,the content of Glutathione disulphide(GSSG)in transgenic Arabidopsis and castor hairy root was significantly higher than that in wild type,and the content of Glutathione(GSH)in transgenic Arabidopsis and castor hairy root was significantly lower than that in wild type.The AsA content of transgenic RcDHAR Arabidopsis and castor hairy roots increased 1.8 and 1.5 times respectively.