ACCUMULATION OF NEW POLYPEPTIDES IN RI T-DNA-TRANSFORMED ROOTS OF TOMATO (LYCOPERSICON-ESCULENTUM) DURING THE DEVELOPMENT OF VESICULAR-ARBUSCULAR MYCORRHIZAE

Root-inducing transferred-DNA (Ri T-DNA)-transformed roots of tomato ( Lycopersicon esculentum) were in vitro inoculated with surface-sterili zed vesicular-arbuscular mycorrhizal leek root pieces. About 1 week af ter inoculation, the infection of the transformed root culture by the fungal endophyte was confirmed by photonic microscopy. Total proteins were extracted from the mycorrhizal roots and analyzed by two-dimensio nal polyacrylamide gel electrophoresis. Control gels were run with pro teins extracted from noninoculated roots mixed with purified intraradi cal vesicles and extraradical hyphae. Comparison of the resulting patt erns revealed the presence of two polypeptides with estimated apparent masses of 24 and 39 kDa that were detected only in infected roots. Po lypeptides with similar migration parameters were not detected in root s challenged with spore extracts, suggesting that the accumulation of the polypeptides was directly linked to root colonization by the fungu s rather than to induction by fungus-derived elicitors.