Study on the Involvement of Auxin Signaling Pathway in Response to Powdery Mildew Stress in Pumpkin
Auxin(IAA)signaling pathway plays an important role in plant growth and response to biological and abiotic stress.Powdery mildew(PM)is a common and serious disease in pumpkin.In order to explore the molecular mechanism of IAA signal-ing pathway in response to PM stress,transcriptomic sequencing and whole genome DNA methylation sequencing were per-formed on pumpkin leaves treated with PM.As a result,we found 25 differentially expressed genes in the IAA signaling pathway.Fifty-three genes were differentially methylated,among which 16 austerin-upregulated small RNA(SAUR)genes were methylat-ed to different degrees,suggesting that these genes may be involved in the response to powdery mildew stress.The methylation level of SAUR50(CmoCh19G007170)gene was reduced,and the methylation region was located in the promoter region of the gene.The expression level of SAUR50 was significantly up-regulated under PM stress and significantly down-regulated under IAA induction.Therefore,this gene may regulate its expression level through DNA methylation and participate in the regulation of PM stress in pumpkin through IAA signaling pathway.The results provided a theoretical basis for IAA signaling pathway in response to powdery mildew stress molecular breeding of pumpkin resistant to PM.