A single amino acid substitution in highly similar endo-PGs from Fusarium verticillioides and related Fusarium species affects PGIP inhibition.
Endo-polygalacturonase (PG) may be a critical virulence factor secreted by several fungi upon plant invasion. The single-copy gene encoding PG in Fusarium verticillioides and in eight other species of the Gibberella fujikuroi complex (F. sacchari, F. fujikuroi, F. proliferatum, F. subglutinans, F. thapsinum, F. nygamai, F. circinatum, and F. anthophilum) was functionally analyzed in this paper. Both the nucleotide and amino acid sequences were highly similar among the 12 strains of F. verticillioides analyzed, as well as among those from the G. fujikuroi complex. The PGs were not inhibited by the polygalacturonase-inhibiting proteins (PGIPs) from the monocot asparagus and leek plants, but were inhibited to variable extents by bean PGIP. PGs from F. verticillioides, F. nygamai and one strain of F. proliferatum were barely inhibited. Residue 97 within PG was demonstrated to contribute to the different levels of inhibition. Together these findings provide new insights into the structural and functional relationships between the PG from the species of the G. fujikuroi complex and the plant PGIP.
Raiola
A
A
Department of Territorio e Sistemi Agro-Forestali, Research Group Plant Pathology, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro, Italy.
Sella
L
L
Castiglioni
C
C
Balmas
V
V
Favaron
F
F
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry; D005670:Fusarium / Q000201:enzymology* / Q000235:genetics; D019668:Liliaceae / Q000737:chemistry; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D019697:Onions / Q000737:chemistry; D010802:Phylogeny; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D011096:Polygalacturonase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D004271:DNA, Fungal; D004791:Enzyme Inhibitors; D050505:Mutant Proteins; C081479:PGIP protein, plant; D010940:Plant Proteins; D011096:Polygalacturonase