The Botrytis cinerea early secretome

Abstract

The extracellular proteome, or secretome, of phytopathogenic fungi is presumed to be a key element of their infection strategy. Especially interesting constituents of this set are those proteins secreted at the beginning of the infection, during the germination of conidia on the plant surfaces or wounds, since they may play essential roles in the establishment of a successful infection. We have germinated Botrytis cinerea conidia in conditions that resemble the plant environment, a synthetic medium enriched with low-molecular weight plant compounds, and we have collected the proteins secreted during the first 16 hours by a double precipitation protocol. 2D electrophoresis of the precipitated secretome showed a spot pattern similar for all conditions evaluated and for the control medium without plant extract. The proteins in 16 of these spots were identified by PMF and corresponded to 11 different polypeptides. Alternative determination of secretome composition by liquid chromatography-tandem mass spectrometry of tryptic fragments rendered a much larger number, 105 proteins, which included all previously identified by PMF. All proteins were functionally classified according to their putative function in the infection process. Key features of the early secretome include a large number of proteases, the abundance of proteins involved in the degradation of plant defensive barriers, and plenty of proteins with unknown function.

Investigating Aspergillus nidulans secretome during colonisation of cork cell walls

“…Additional proteases were found in the cork secretome (AN2366, AN2903 and AN3918), similar to that reported in the secretome of A. nidulans grown on sorghum stover or on leaf litter [46,47]. Their involvement in the hydrolysis of secreted proteins has been suggested in the secretome of fungi other than A. nidulans [37]. Some proteins species in the cork secretome were probably induced by carbon starvation conditions, such as glutaminase A (AN4809) [52] and acid phosphatase (AN4055) [54].…”

“…As frequently reported in fungal secretomes, multiple isoforms of the same protein species were herein detected. This is generally related to posttranslational modifications, of which glycosylation is the most frequently reported [36] and in some cases also to proteolysis [37]. The identified proteins were grouped according to their biological functions, namely fungal cell wall remodelling enzymes, plant cell wall degrading enzymes, defence/stress response, proteases/nitrogen and miscellaneous (Table 3).…”

Arabidopsis PECTIN METHYLESTERASEs Contribute to Immunity against Pseudomonas syringae

“…Pectolytic, necrotrophic pathogens, such as the fungus Botrytis cinerea, secrete pectin-degrading enzymes, including pectate lyases and polygalacturonases as well as PMEs early during infection (Espino et al, 2010). Moreover, the B. cinerea endopolygalacturonases Bcpg1 and Bcpg2 and the PME Bcpme1 are required for full virulence (ten Have et al, 1998;Valette-Collet et al, 2003;Kars et al, 2005), illustrating the importance of pectin degradation for the success of this pathogen.…”

Degradation of Food Manufacturing Wastes by a Fungal Isolate

“…These results suggest the presence of mechanisms to degrade or transform phenolic compounds from the culture medium present on OMSW and GP cultures (Schouten et al, 2002). It is known that strain T1 secretes laccases that could be responsible for phenolic compounds oxidation (Espino et al, 2010;González-Fernández et al, 2014) (Fig. 2C).…”

“…2B). These results suggest the presence of metabolic activity possibly due to extracellular enzymes produced by strain T1 (Espino et al, 2010;González-Fernández et al, 2014). Similarly, total phenolic compounds were measured after inoculation with strain T1.…”