Genome-Wide Analysis of the Serine Carboxypeptidase-like (SCPL) Protein Family of Bitter Gourd and Functional Validation of McSCPL22 in Fusarium oxysporum f. sp. Momordicae (FOM) Resistance

• Published in: International journal of molecular sciences Vol. 25; no. 21; p. 11816
• Main Authors: Guan, Feng, Yang, Xuetong, Shi, Bo, Wang, Kai, Zhang, Jingyun, Xie, Yuanyuan, Wan, Xinjian
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 03.11.2024; MDPI
• Subjects: Abscisic acid; Disease; Genes; Genomes; Hydrogen peroxide; Pathogens; Phylogenetics; Proteins
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms252111816

Bitter gourd is increasingly being recognized for its value as a vegetable and medicinal use, but the molecular mechanisms of pathogen resistance remain relatively poorly understood. The serine carboxypeptidase-like (SCPL) protein family plays a key role in plant growth, pathogen defense, and so on. However, a comprehensive identification and functional characterization of the SCPL gene family has yet to be conducted in bitter melon. In this study, 32 SCPL genes were identified in bitter gourd and divided into three classes. The number of SCPL genes contained in the three clusters was 7, 7, and 18, respectively. Most SCPL gene promoters contain cis-acting elements with light, hormone, and stress responses. The RNA sequencing data showed that the expression of several SCPL genes changed significantly after pathogen infection. In particular, expression of the McSCPL4, 10, 17, 22, and 25 genes increased substantially in the resistant varieties after infection, and their expression levels were higher than those in the susceptible varieties. These results suggested that genes such as McSCPL4, 10, 17, 22, and 25 may play a significant role in conferring resistance to fungal infections. Moreover, the expression levels of the McSCPL10, 17, 22, 23, and 25 genes were likewise significantly changed after being induced by salicylic acid (SA) and jasmonic acid (JA). In situ hybridization showed that McSCPL22 was expressed in the vascular tissues of infected plants, which largely overlapped with the location of Fusarium oxysporum f. sp. Momordicae (FOM) infection and the site of hydrogen peroxide production. Our results showed that McSCPL22 may be involved in the regulation of the SA and JA pathways and enhance resistance to FOM in bitter gourd plants. This is the first study to perform SCPL gene family analysis in bitter gourd. McSCPL22 may have the potential to enhance FOM resistance in bitter gourd, and further investigation into its function is warranted. The results of this study may enhance the yield and molecular breeding of bitter gourd.