PdMesA regulates polar growth, cell wall integrity, and full virulence in Penicillium digitatum of citrus

• Published in: Postharvest biology and technology 2024-09, Vol.215, p.113017, Article 113017
• Main Authors: Liu, Shuqi, Liu, Xinying, Lai, Weiqiang, Lu, Yongqing, Wang, Yuqing, Long, Chao-an
• Format: Article
• Language: English
• Subjects: cell polarity; Cell wall integrity; cell walls; chitin synthase; Citrus; endo-1,4-beta-glucanase; genes; hyphae; Hyphal polarity; industry; morphogenesis; PdMesA; Penicillium digitatum; polygalacturonase; spore germination; technology; Virulence; virulent strains
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2024.113017

Penicillium digitatum is a pathogenic fungus of postharvest green mold in citrus, leading to significant economic losses in the citrus industry. The establishment of cell polarity in filamentous fungi plays a pivotal role in morphogenesis, colonization, and host infection. Here we present the functional characterization of PdMesA to elucidate its significance in the development and virulence of P. digitatum. The results demonstrate that deletion mutants of the PdMesA gene exhibit hyphal distortion, increased hyphal branching, and decreased spore germination rate, suggesting that PdMesA is involved in the maintenance of cell polarity. Additionally, the RTqPCR analysis of the ΔPdMesA mutants exhibited significant changes in the expression of the chitin synthase gene in ΔPdMesA. These changes could account for the enhanced tolerance of the ΔPdMesA strain towards SDS, CR, and CFW. Therefore, PdMesA is essential for cell wall structural and functional integrity. Furthermore, deletion of the PdMesA gene suppresses pectinase, cellulase, and organic acid-related genes, resulting in the virulence of P. digitatum being considerably diminished. Our study reveals that PdMesA regulates hyphal polar growth, cell wall integrity, and full virulence in P. digitatum. Consequently, PdMesA holds significant promise as a target for the research of innovative fungicides. •PdMesA is a critical gene for maintaining the polar growth of P. digitatum.•PdMesA maintains cell wall integrity by regulating CHS gene expression.•PdMesA is involved in the response of P. digitatum to DMI fungicides.•PdMesA deletion reduced the virulence of P. digitatum in citrus.