Preliminary Study Of Cotton HDAC And ERF Genes Anti-Verticillium Wilt

Cotton is an important fiber and oil crop.Cotton is exposed to various biotic and abiotic factors leading to a significant amount of yield losses.Verticillium wilt is a soil-borne vascular disease,which heavily hinders cotton production.Cultivated cotton species are sensitive to diseases,insect pests and abiotic stresses,while wild species are rich in genetic diversity possessing excellent agronomic traits and genetic resources and have not been widely used.Using modern molecular approaches to explore the wild germplasm for the identification of verticillium wilt resistant genes and addressing the underlying disease resistance mechanism you be a great achievement and it would be helpful in marker assisted selection and creating disease resistant germplasm.Histone deacetylases(HDACs)and ethylene responsive factors(ERFs)play important roles in plant development and stress responses.In this study,we did the genome wide analysis of the cotton HDAC gene family and their response to Verticillium wilt.Based on whole-genome sequencing,combined with G.australe transcriptome data at different time intervals after verticillium wilt attack,the GauERF105 gene was selected as the candidate gene.Further we performed the functional validation to prove the role of GauERF105 in response to disease attack.Following are the major findings of current research work:1.Identification and analysis of HDAC family genes in cotton:There are 30,15,13 and 20 HDAC gene family members identified in the genome of G.hirsutum(ADI),G.arboreum(A2),G.thurberi(D1)and G.australe(G2);HDACs are divided into three subfamilies RPD3/HDA1,HD2 and SIR2,and members of the same subfamily have similar gene structures and conserved motifs;promoter regions contains a large number of hormone response,stress-related response elements and cis-acting elements related to plant growth and development.RNA-seq combined with qRT-PCR found that most HDAC genes are upregulated under Verticillium wilt attack.HDACs members respond to the induction of ethylene,salicylic acid and jasmonic acid,indicating that this gene family may be involved in ET/JA and SA signaling pathways to regulate cotton’s defense response to Verticillium wilt(VW).2.Virus induced gene silencing(VIGS)was used to silence the GauERF105.Silencing of GauERF105 decreased the resistance to VW with a higher susceptible phenotypes,more severe defoliation,and yellowing symptoms were observed.The stalk lignin staining results showed that the coloring of the plants with silent GauERF105 gene after inoculation were significantly lighter than the control plants,thus indicating that interference with the expression of the GauERF105 homologous gene reduced the synthesis of lignin and thus weakened the ability of plants to resist Verticillium wilt.3.Over-expression of GauERF105 was performed in Arabidopsis thaliana.The Arabidopsis overexpressing plants with GauERF105 were obtained by transgenic technology.After inoculating wild-type and transgenic plants with Verticillium dahliae,the transgenic plants had enhanced disease resistance.The quantitative results of Verticillium dahliae showed that more fungus was accumulated in wild-type plants.The DAB and Trypan blue staining results showed that the transgenic lines had lighter staining,indicating that the overexpression of GauERF1 05 reduced the damage of Verticillium wilt to plants.4.The results of gene expression analysis showed that silencing the GauERF105 gene reduced the expression of GhPR3,GhPR4 and GhPR5 in cotton leaves,while overexpression of the GauERF105 gene promoted the expression of AtPR3,AtPR4 and AtPDF1.2 in Arabidopsis.As a downstream factor of the ethylene signaling pathway,GauERF105 enhances the resistance to Verticillium wilt by activating the expression of some diseaserelated genes.The above results preliminarily clarified the functions of HDAC and ERF in response to Verticillium wilt resistance,laying a theoretical foundation for the in-depth elucidation of the control network of resistance to Verticillium wilt in cotton,and providing basic materials for the selection of new varieties resistant to Verticillium wilt,which have important practical significance.The research results have important practical significance for the selection of new varieties resistant to Verticillium wilt.Current results confirm that HDAC and genes play a very important role in Verticillium wilt resistance.Our findings add a significantly to the existing knowledge about Verticillium wilt resistance specifically in wild cotton.Further in-depth molecular and genetic studies are required to understand the defense networking in response to Verticillium wilt attack.