The High-Affinity Phosphodiesterase BcPde2 Has Impact on Growth, Differentiation and Virulence of the Phytopathogenic Ascomycete Botrytis cinerea

Abstract

Components of the cAMP signaling pathway, such as the adenylate cyclase Bac and the protein kinase A (PKA) were shown to affect growth, morphogenesis and differentiation as well as virulence of the phytopathogenic fungus Botrytis cinerea. While loss of Bac caused drastically reduced intracellular cAMP levels, deletion of the PKA resulted in extremely increased cAMP concentrations. To regulate the intracellular level of the second messenger cAMP, a balance between its biosynthesis through adenylate cyclase activity and its hydrolysis by phosphodiesterases (PDEs) is crucial. Here, we report the functional characterization of the two PDEs in the ascomycete B. cinerea, BcPde1 and BcPde2. While deletion of bcpde2 resulted in severely affected vegetative growth, conidiation, germination and virulence, the bcpde1 deletion strain displayed a wild-type-like phenotype. However, the double bcpde1/2 deletion mutant exhibited an even stronger phenotype.Localization studies revealed that BcPde2 accumulates at the plasma membrane, but is also localized in the cytoplasm. BcPde1 was shown to be distributed in the cytoplasm as well, but also accumulates in so far unknown mobile vesicles. Overexpression of bcpde1 in the Δbcpde2 background rescued the deletion phenotype, and in addition an increased transcript level of bcpde1 in the Δbcpde2 strain was observed, indicating redundant functions of both PDEs and an interdependent gene expression.

TRI6 and TRI10 play different roles in the regulation of deoxynivalenol (DON) production by cAMP signalling in Fusarium graminearum

“…In M. oryzae , deletion of PDEH , an ortholog of yeast PDE2 , results in an elevated intracellular cAMP level and defects in appressorium development but deletion of PDEL has no obvious phenotypes (Ramanujam and Naqvi, ; Zhang et al ., ). In Botrytis cinerea , the pde2 deletion mutant is defective in vegetative growth, differentiation and virulence although it has a reduced intracellular cAMP level (Harren et al ., ). In human pathogen Candida albicans , PDE2 deletion mutant also has an increased intracellular cAMP level and it is defective in nutrient sensing, filamentation and cell wall and membrane integrity (Jung et al ., ).…”

Identification of a Universal Marker for Detecting Possible Mutation in Botrytis cinerea Isolates Associated with Virulence

“…Since we were not able to see similar results in our wild type isolates, we can conclude that the mutation can be considered as a possible reason for larger conidia size and virulence. It has also been reported that the larger conidia are usually fungicide resistant, have a greater life span, and are more virulent in Botrytis [46]. Since there is currently no efficient alternative to control Botrytis, the fungal pathogen is recognized by the Fungicide Resistance Action Committee (FRAC) as a pathogen at high risk of fungicide resistance development.…”

“…Thus, it is a serious issue for growers, scientists, and manufacturers. It not only reduces growers' and manufacturers' income, but it also has consequences for the environment and human health [46]. Therefore, using a genomic approach to identify diversity [47] within the fungal species, then connecting that diversity to morphological variation and virulence, will provide the initial knowledge needed to better understand the pathogen.…”

Caffeine fostering of mycoparasitic fungi against phytopathogens

“…For example, the quality and quantity of the target phosphodiesterases such as affinity (Km), structure of isoforms and copy numbers differ among fungi. 31,42,43 Properties of signaling components including protein kinases and G proteins 44,45 may be diverse.…”