Characterization of the Role of a Non-GPCR Membrane-Bound CFEM Protein in the Pathogenicity and Germination of Botrytis cinerea.

Gulab Chand Arya,Dhruv Aditya Srivastava,Eswari P J Pandaranayaka,Dov Bernard Prusky,Hay Dvir,Omer Frenkel,Ekaterina Manasherova,Yigal Elad,Arye Harel

doi:10.3390/microorganisms8071043

Gulab Chand Arya, Dhruv Aditya Srivastava + Show 7 more

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https://doi.org/10.3390/microorganisms8071043

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Journal: Microorganisms	Publication Date: Jul 14, 2020
Citations: 12	License type: CC BY 4.0

Affiliation: Agricultural Research Organization

Abstract

The necrotrophic fungus Botrytis cinerea, is considered a major cause of postharvest losses in a wide range of crops. The common fungal extracellular membrane protein (CFEM), containing a conserved eight-cysteine pattern, was found exclusively in fungi. Previous studies in phytopathogenic fungi have demonstrated the role of membrane-bound and secreted CFEM-containing proteins in different aspects of fungal virulence. However, non-G protein-coupled receptor (non-GPCR) membrane CFEM proteins have not been studied yet in phytopathogenic fungi. In the present study, we have identified a non-GPCR membrane-bound CFEM-containing protein, Bcin07g03260, in the B. cinerea genome, and generated deletion mutants, ΔCFEM-Bcin07g03260, to study its potential role in physiology and virulence. Three independent ΔCFEM-Bcin07g03260 mutants showed significantly reduced progression of a necrotic lesion on tomato (Solanum lycopersicum) leaves. Further analysis of the mutants revealed significant reduction (approximately 20–30%) in conidial germination and consequent germ tube elongation compared with the WT. Our data complements a previous study of secreted ΔCFEM1 mutants of B. cinerea that showed reduced progression of necrotic lesions on leaves, without effect on germination. Considering various functions identified for CFEM proteins in fungal virulence, our work illustrates a potential new role for a non-GPCR membrane CFEM in pathogenic fungi to control virulence in the fungus B. cinerea.

Highlights

Botrytis cinerea, the causal agent of gray mold, is a necrotrophic fungal pathogen that is considered a major cause of postharvest losses in a wide range of crops including fruits, vegetables, and flowers [1]
Studies in the mammal pathogens Candida albicans and C. parapsilosis illustrated that a subclass of the common fungal extracellular membrane proteins (CFEM) family of proteins are involved in utilization of heme and hemoglobin as iron sources [11,20,21]
Results of real-time quantitative PCR confirmed that the expression of CFEM-Bcin07g03260 in these mutants (∆CFEM-T4, ∆CFEM-T7 and ∆CFEM-T8) is negligible (Figure 1d)

Summary

Introduction

Botrytis cinerea (teleomorph: Botryotinia fuckeliana), the causal agent of gray mold, is a necrotrophic fungal pathogen that is considered a major cause of postharvest losses in a wide range of crops including fruits, vegetables, and flowers [1]. The common fungal extracellular membrane proteins (CFEM), containing a conserved eight-cysteine pattern [10], have been found exclusively in fungi (mainly Ascomycota, and Basidiomycota) [10,11,12,13], and they were found to be enriched in pathogenic fungi [14]. This domain was found to participate in various functions mediating different physiological (e.g., cell wall stability [15,16]) and infection processes [10,17,18,19]. These CFEM proteins contain a secreted Csa, glycosylphosphatidylinositol (GPI) cell wall-bound Rbt, and the more internal cell wall and plasma membrane anchored Pga

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