Surface component characterization as taxonomic tools for Phytomonas spp identification

The genus Phytomonas arbitrarily includes all protozoa of the family Trypanosomatidae isolated from plants, but its differentiation is a complex task. The phase separation technique using Triton X-114 was used to analyze hydrophobic and hydrophilic surface proteins in ten strains of Phytomonas isolated from various fruits. The iodination of surface proteins by the Iodo-Gen method was also used for Phytomonas isolates from tomatoes, corn and annatto, Herpetomonas samuelpessoai and Crithidia fasciculata. The distribution of protein-bound radioactivity in acrylamide gels was determined by autoradiograms and showed the presence of protein bands of 36–68 kDa in all strains of Phytomonas: there were two major bands at 88 kDa and 94 kDa, with minor bands at 36 kDa and 142 kDa in H. samuelpessoai; and there were three bands at 74, 86 and 94 kDa, with minor bands at 23 kDa and 105 kDa in C. fasciculata. The results demonstrated that samples of plant parasites can be clearly differentiated from H. samuelpessoai and C. fasciculata. These plant parasites were also submitted to polysaccharide analysis by gas-liquid chromatography of the corresponding alditol acetate. Arabinose, galactose, glucose and mannose, were the major monosaccharides found, while fucose, rhamnose and xylose were found in smaller amounts. The results of all these methods indicated that, after extension to a wider range of trypanosomatid strains, they may be useful in Phytomonas taxonomy. Received: 10 June 2000 / Accepted: 9 August 2000