Determination of Coniothyrium minitans conidial and germling lectin avidity by flow cytometry and digital microscopy

The avidity of conidia and 48-h-old germlings of Coniothyrium minitans for FITC-conjugated lectins was characterised by flow cytometry and digital mic roscopy. Six isolates of C. minitans representing three morphological types were compared. Binding of Con A. SBA and WGA by conidial populations varie d markedly in extent and pattern between isolates, however, with increasing culture age, conidia from all isolates demonstrated a significant reductio n in lectin avidity. Germling isolates bound significantly different amount s of lectins and lectin binding differed significantly with locality. Spore walls of ail germlings from all isolates bound more Con A compared with hy phal spices and mature hyphal walls. In contrast, hyphal spices of the majo rity of germling isolates, readily bound SBA and mature hyphal walls of ger mling isolates bound more WGA than other regions of the germlings. Such dif ferential lectin binding by conidia and germlings may influence their speci fic surface interactions and adherence characteristics.