IMMUNOCYTOCHEMICAL LOCALIZATION OF PHYTOTOXINS IN BIPOLARIS-SOROKINIANA

Polyclonal antibodies against prehelminthosporol, a phytotoxin produce d 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 antibo dies was investigated with indirect ELISAs. The antibodies bound both to free prehelminthosporol and to a prehelminthosporol-bovine serum al bumin conjugate bound to microtiter wells, The antibodies showed less affinity to structurally related compounds from the fungus, No cross-r eactivity was shown for proteins extracted from mycelium of B, sorokin iana, Low-temperature preparation techniques for electron microscopy w ere used in combination with immunogold labeling for localization of p rehelminthosporol 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 Wor onin bodies, (C) 1996 Academic Press, Inc.