A pathogenesis-related protein 1 of Cucurbita moschata responds to powdery mildew infection

Wei-Li Guo; He-Lian Yang; Jin-Peng Zhao; Shi-Jie Bian; Yan-Yan Guo; Xue-Jin Chen; Xin-Zheng Li

doi:10.3389/fgene.2023.1168138

A pathogenesis-related protein 1 of Cucurbita moschata responds to powdery mildew infection

Front Genet. 2023 Aug 1:14:1168138. doi: 10.3389/fgene.2023.1168138. eCollection 2023.

Authors

Wei-Li Guo^{1

2}, He-Lian Yang¹, Jin-Peng Zhao¹, Shi-Jie Bian¹, Yan-Yan Guo¹, Xue-Jin Chen¹, Xin-Zheng Li¹

Affiliations

¹ School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang, China.
² Henan Province Engineering Research Center of Horticultural Plant Resource Utilization and Germplasm Enhancement, Xinxiang, China.

Abstract

Pumpkin (Cucurbita moschata Duch.) productivity is severely hindered by powdery mildew (PM) worldwide. The causative agent of pumpkin PM is Podosphaera xanthii, a biotrophic fungus. Pathogenesis-related protein 1 (PR1) homolog was previously identified from transcriptomic analysis of a PM-resistant pumpkin. Here, we investigated the effects of CmPR1 gene from pumpkin for resistance to PM. Subcellular localization assay revealed that CmPR1 is a cytoplasmic protein in plants. The expression of CmPR1 gene was strongly induced by P. xanthii inoculation at 48 h and exogenous ethylene (ET), jasmonic acid (JA) and NaCl treatments, but repressed by H₂O₂ and salicylic acid (SA) treatments. Visual disease symptoms, histological observations of fungal growth and host cell death, and accumulation of H₂O₂ in transgenic tobacco plants indicated that CmPR1 overexpression significantly enhanced the resistance to Golovinomyces cichoracearum compared to wild type plants during PM pathogens infection, possibly due to inducing cell death and H₂O₂ accumulation near infected sites. The expression of PR1a was significantly induced in transgenic tobacco plants in response to G. cichoracearum, suggesting that CmPR1 overexpression positively modulates the resistance to PM via the SA signaling pathway. These findings indicate that CmPR1 is a defense response gene in C. moschata and can be exploited to develop disease-resistant crop varieties.

Keywords: Cucurbita moschata; PR-1; functional analysis; powdery mildew; transgenic tobacco.

Grants and funding

This work was supported by National Natural Science Foundation of China (No. U2004161; 31401876) and Science and Technology Project of Henan Province (Grant no. 212102110129; 222102110184).