Kinetoplast DNA minicircles of phloem-restricted Phytomonas associated with wilt diseases of coconut and oil palms have a two-domain structure

We report the cloning and sequencing of the first minicircle from a phloem- restricted, pathogenic Phytomonas sp. (Hart 1) isolated from a coconut palm with hartrot disease. The minicircle possessed a two-domain structure of t wo conserved regions. each containing three conserved sequence blocks (CSB) . Based on the sequence around CSB 3 from Hart 1, PCR primers were designed to allow specific amplification of Phytomonas minicircles, This primer pai r demonstrated specificity for at least six groups of plant trypanosomatids and did not amplify from insect trypanosomatids. The PCR results were cons istent with a two-domain structure for other plant trypanosomatids. (C) 200 1 Published by Elsevier Science B.V. on behalf of the Federation of Europea n Microbiological Societies.