Immunocytochemical localization of phytotoxins in Bipolaris sorokiniana

Polyclonal antibodies against prehelminthosporol, a phytotoxin produced by the plant pathogenic fungus Bipolaris sorokiniana, were raised in rabbits immunized with a prehelminthosporol-hexon conjugate, The IgG was isolated from the serum and the specificity of the purified antibodies was investigated with indirect ELISAs. The antibodies bound both to free prehelminthosporol and to a prehelminthosporol-bovine serum albumin conjugate bound to microtiter wells, The antibodies showed less affinity to structurally related compounds from the fungus, No cross-reactivity was shown for proteins extracted from mycelium of B, sorokiniana, Low-temperature preparation techniques for electron microscopy were used in combination with immunogold labeling for localization of prehelminthosporol in hyphae and germinated conidia of B, sorokiniana, A low level of labeling was obtained throughout the cytoplasm, and the main labeling was seen in membrane-bound organelles identified as Woronin bodies, (C) 1996 Academic Press, Inc.