Comparative proteomics of extracellular proteins in vitro and in planta from the pathogenic fungus Fusarium graminearum

Abstract

High-throughput MS/MS was used to identify proteins secreted by Fusarium graminearum (Gibberella zeae) during growth on 13 media in vitro and in planta during infection of wheat heads. In vitro secreted proteins were collected from the culture filtrates, and in planta proteins were collected by vacuum infiltration. A total of 289 proteins (229 in vitro and 120 in planta) were identified with high statistical confidence. Forty-nine of the in planta proteins were not found in any of the in vitro conditions. The majority (91-100%) of the in vitro proteins had predicted signal peptides, but only 56% of the in planta proteins. At least 13 of the nonsecreted proteins found only in planta were single-copy housekeeping enzymes, including enolase, triose phosphate isomerase, phosphoglucomutase, calmodulin, aconitase, and malate dehydrogenase. The presence of these proteins in the in planta but not in vitro secretome might indicate that significant fungal lysis occurs during pathogenesis. On the other hand, several of the proteins lacking signal peptides that were found in planta have been reported to be potent immunogens secreted by animal pathogenic fungi, and therefore could be important in the interaction between F. graminearum and its host plants.

Structure and Substrate Specificity of a Eukaryotic Fucosidase from Fusarium graminearum

“…F. graminearum also encodes two hypothetical GH95 family enzymes, FG04734.1 and FG11516.1, based on a BLASTP search using AtFuc95A sequence (NP_195152.2) (18) as the query. However, unlike FgFCO1, a GH95 fucosidase was not detected by comparative proteomics analysis in the secretome of F. graminearum under the same growth conditions by which FgFCO1 was induced (71).…”

“…XXFG is not only a plant cell wall structural unit but also a plant signaling molecule whose fucose moiety is essential to its antiauxin activity (72,73). Second, FgFCO1 is induced specifically by growth of F. graminearum on media containing various plant cell wall materials (71). Third, F. graminearum is one of the world's most serious pathogens of plants (74).…”

Shotgun Analysis of the Secretome of Fusarium graminearum

“…Therefore, no experiment is saturating in regard to defining the entire secretome. Because many secreted proteins are virulence or virulence effectors and constitute the first contact between a pathogen and its host [8], all the secreted proteins identified in our study and earlier reports are promising candidates to have a role in pathogenesis, and might provide new insights into Fusarium/plants interactions [7,8].…”

“…Proteomic analysis, however, has been proven to be the most powerful method for the identification of proteins in complex mixtures and is suitable for studying the modification of protein expression in an organism due to genetic and/or environmental variations [2]. The exoproteome of the fungus F. graminearum grown on different media were investigated [7][8][9], and more than three hundreds proteins secreted were identified. Comparing these studies, it can be drawn that the actual compositions of the secretome of F. graminearum grown on different media were different, and no experiment is saturating in regard to defining all the proteins secreted by the fungus at any given time or under certain condition.…”

FgLPMO9A from Fusarium graminearum cleaves xyloglucan independently of the backbone substitution pattern

“…F. graminearum is an efficient degrader of plant biomass, secreting cell wall degrading enzymes, including cellulases, xylanases, pectinases and LPMOs [10,11].…”