Functional Analysis Of GbWAK3 In Cotton Responsive To Verticillium Dahliae

Extracellular domain of WAKs can bind pectin components in the wall and accept the signal of the cell wall structure modifications,which are necessary both for participating in cell during development and for a response to pathogens in immune process.In our previous study,a gene putatively encoded a protein kinase was isolated,which could induced by a variety of pathogens[1]6683,suggesting that may involved in broad-spectrum resistance in the plant.The gene shows highly homology similarity to At WAK3 and was named Gb WAK3.The functions of Gb WAK3 response to V.dahliae in cotton were investigated.The main results as followings:The analysis showed that Gb WAK3 was expressed in different tissues of Gossypium barbadense,with the highest expression level in root and and the second in leaf tissue cotton.By the analysis of bioinformatics,Gb WAK3 was up-regulated by the induction of Verticillium dahliae at the transcriptional level;after spraying SA,the expression of Gb WAK3 did not increase significantly and the expression of Gb WAK3 increased rapidly after spraying Me JA.Therefore,Gb WAK3 was highly expressed in the roots of Gossypium barbadense and was induced by Verticillium dahliae.The expression level of Gb WAK3 was increased rapidly by methyl jasmonate.Inhibit the expression of Gb WAK3 by VIGS,the resistance of cotton to Verticillium dahliae is reduced;Arabidopsis thaliana wak3 mutant also became more susceptible upon inoculation of V.dahliae.Analysis found that inhibit the expression of Gb WAK3 or Arabidopsis thaliana wak3 mutant resulted in decreased expression of JA pathway-related genes and lignin-related genes and JA content and lignin content decreased.Meanwhile,the inhibition of Gb WAK3 expression in cotton leaves more be more susceptible to necrotrophic fungus Botrytis cinerea.The above results indicate that Gb WAK3 may affect the immune response of cotton by regulating the JA signal pathway and lignin metabolism.