Snf1 Kinase Differentially Regulates Botrytis cinerea Pathogenicity according to the Plant Host

Abstract

The Snf1 kinase of the glucose signaling pathway controls the response to nutritional and environmental stresses. In phytopathogenic fungi, Snf1 acts as a global activator of plant cell wall degrading enzymes that are major virulence factors for plant colonization. To characterize its role in the virulence of the necrotrophic fungus Botrytis cinerea, two independent deletion mutants of the Bcsnf1 gene were obtained and analyzed. Virulence of the Δsnf1 mutants was reduced by 59% on a host with acidic pH (apple fruit) and up to 89% on hosts with neutral pH (cucumber cotyledon and French bean leaf). In vitro, Δsnf1 mutants grew slower than the wild type strain at both pH 5 and 7, with a reduction of 20–80% in simple sugars, polysaccharides, and lipidic carbon sources, and these defects were amplified at pH 7. A two-fold reduction in secretion of xylanase activities was observed consequently to the Bcsnf1 gene deletion. Moreover, Δsnf1 mutants were altered in their ability to control ambient pH. Finally, Δsnf1 mutants were impaired in asexual sporulation and did not produce macroconidia. These results confirm the importance of BcSnf1 in pathogenicity, nutrition, and conidiation, and suggest a role in pH regulation for this global regulator in filamentous fungi.

Xylanase-Producing Microbes and Their Real-World Application

“…[112] Verticillium dahlia; Cochliobolus sativus; Pyrenophora tritici-repentis; Fusarium tricinctum; Penicillium cyclopium; Penicillium freii [113] Papiliotrema laurentii SDBR-CMU-S1-02; Rhodosporidiobolus ruineniae; Apiotrichum scarabaeorum; Aureobasidium melanogenum; Galactomyces sp. S3-06 [114] Rhizopus oryzae strain NRRL 29086; Epicoccum nigrum (MH102081); Trichoderma paraviridescens; Penicillium brevicompactum [115] Aspergillus luchuensisInui strain RF7398; Aspergillus acidus (strain RF 7398) [116] Penicillium canescens (PcXylA) [117] Talaromyces amestolkiae [118] Aspergillus oryzae strain NZYM-FA [119] Fusarium graminearum; Acremonium cellulolyticus; Talaromyces versatilis; Penicillium chrysogenum P33; Talaromyces leycettanus [120] Botrytis cinerea [121] Aspergillus giganteus; Chaetomium trilateral…”

Unravelling the Interplay of Nitrogen Nutrition and theBotrytis cinereapectin lyase BcPNL1 in ModulatingArabidopsis thalianaSusceptibility

“…Consequently, only a few genes have been described as having a major role in pathogenicity. Among them, some transcription factors and kinases have been identified, such as sucrose non-fermenting protein kinase 1 (BcSNF1) and the pH regulator BcPACC (Lengyel et al, 2022; Rascle et al, 2018). Furthermore, chitin synthases like Bcchs3a are also important pathogenicity factors, influencing fungal adhesion to the host and activating plant defense mechanisms (Arbelet et al, 2010).…”