Functional study of PtPTA and PtDLO1 in disease resistance of Pinellia ternata to soft rot by an efficient Agrobacterium tumefaciens-mediated transformation system

Pinellia ternata (Thunb.) Breit, belonging to the genus Pinellia in the Araceae family, is globally distributed. The dried tuber of P. ternata has significant medicinal value in traditional Chinese medicine, with a history of usage spanning approximately 2000 years, particularly for alleviating cough and vomiting. However, soft rot disease caused by Pectobacterium carotovorum poses a severe threat to P. ternata plants. This study screened 44 germplasms and identified the disease-resistant Pinellia ternata P-9 and disease-susceptible Pinellia ternata P-15. A de novo transcriptome analysis was conducted to explore the key genes associated with disease resistance. Among these, a mannose-binding lectin PTA gene (PtPTA) and a DMR6-like oxygenase 1 gene (PtDLO1) were identified as resistance-related genes through transient expression assays. Subsequently, a highly efficient genetic transformation system for Pinellia ternata, achieving a positive rate exceeding 70%, was optimized to validate the function of candidate genes. Overexpression of PtPTA significantly enhanced the resistance of Pinellia ternata to Pectobacterium carotovorum, while overexpression of PtDLO1 increased susceptibility to Pectobacterium carotovorum. These findings highlight the pivotal roles of PtPTA and PtDLO1 in conferring disease resistance in Pinellia ternata against soft rot, contributing to the functional analysis of key genes and resistance molecular breeding of Pinellia ternata.