Phylogenetic analysis of elongation factor Tu gene of phytoplasmas from Japan

摘要

The elongation factor Tu (tuf) gene from nine Japan phytoplasma isolates was amplified with the polymerase chain reaction, and the DNA sequences of the tuf gene were determined. The tuf gene from 14 phytoplasma isolates, including reference isolatesand other bacteria, were phylogenetically analyzed. A nucleotide sequence of the tuf gene among seven aster yellows group (16Sr I-B and I-D) phytoplasmas had 97 percent-100 percent similarity, and the tuf gene of two phytoplasmas of the X-disease group (16Sr III-B) had 99 percent similarity. The tuf genes had lower homology than did the 16S rRNA gene in the phytoplasma groups. A phylogenetic tree of amino acid sequences of the tuf gene was nearly equal to that of the 16S rRNA gene but differed somewhatfrom the tree based on the 16S rRNA gene in that paulownia witches' broom (PaW: 16Sr I-D) and American aster yellows (AAY: 16Sr I-B) were in a subclade.