| In China,cotton is one of the important economic crops,but also the world’s second largest raw materials for textile fiber and edible oil.However,the cultivation of cotton has long been affected by Verticillium wilt,the production and fiber quality of cotton have been greatly damaged which resulted in leading economic losses to the cotton farmers.With the development of science and technology,especially with the successful application of transgenic technology in cotton,it has brought hope to completely overcome the verticillium wilt problem.In recent years,through a variety of technical means,more and more resistance genes were excavated.Among them,GST(Glutathione S-transferases)has become a hot spot in plant resistance research.More and more studies have shown that GST can respond to a variety of biological and abiotic stresses to plants and play an important role in salicylic acid signaling pathways.In this study,GaGSTF9 and GaRPL18 were closely related to Verticillium wilt after analysis of 215 materials using GWAS(genome wide association study),and we focus on the function of GaGSTF9.Its molecular biological characteristics were analyzed by VIGS.Then gene was transformed into Arabidopsis thaliana and its relationship with SA(Salicylic acid)was analyzed by a variety of molecular biological methods.The following experimental results were obtained:1.Gene expression pattern analysisThe results of qRT-PCR showed that GaGSTF9 was induced by Verticillium dahliae in resistant cultivars cotton,but not in the susceptible cultivars cotton.In addition,there are many pathogen-related genes that induced expression,suggesting that these genes cooperate with each other to help plants against the infection of Verticillium dahliae.The results of hormone treatment showed that GaGSTF9 could be induced by SA.2.VIGS experimentWe found that the resistant cultivar cotton became susceptible to infection by constructing VIGS interference vector to interfere GaGSTF9 in resistant cultivar cotton.Furthermore,statistical analysis of disease,quantitative simulation of Verticillium dahliae,recovery experiment and the trypan blue staining also confirmed these results.This suggests that GaGSTF9 plays an important role in the resistance to the infection of Verticillium dahliae.3.Functional analysis of transgenic Arabidopsis thalianaGaGSTF9 was transduced into Arabidopsis thaliana by Agrobacterium tumefaciens,resulting in transgenic Arabidopsis thaliana.Through the identification of transgenic pathogens and a series of molecular experiments,it was found that the resistance of transgenic Arabidopsis was higher than that of wild type Arabidopsis thaliana.Furthermore,by detecting the expression of SA marker gene,the content of SA and the resistance of Arabidopsis thaliana after SA treatment showed that GaGSTF9 was not only induced by SA but also affected the content of SA in Arabidopsis thaliana. |
