Physiological and Gene Expression Analysis of Herbaceous Peony Resistance to Alternaria tenuissima Infection

Leaf spot disease caused by Alternaria pathogens seriously threatens peony production. The physiological mechanism of resistance to the pathogen is little reported. This study aimed reveal defensive peonies in response tenuissima. disease-resistant (R) variety ‘Zi Fengyu’ and susceptible (S) ‘Heihai Botao’ were employed, some parameters leaves analyzed after inoculation with A. tenuissima, mainly including hypersensitive (HR), activity enzymes, expression disease-resistance genes. results showed that compared responses S genotype, HR occurred more rapidly R genotype. Meanwhile, antioxidant enzymes (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase) other two defense (polyphenol oxidase phenylalanine ammonia-lyase) increased significantly, pathogenesis-related (PR) genes (PlPR1, PlPR2, PlPR4B, PlPR5, PlPR10) WRKY (PlWRKY13 PlWRKY65) was strongly induced. These collectively contributed findings provided a theoretical basis for understanding intrinsic leaf breeding varieties using molecular approach.