Diversity of the trifunctional histidine biosynthesis gene (his) in cereal Phaeosphaeria species
Journal
Genome
Journal Volume
50
Journal Issue
6
Pages
595-609
Date Issued
2007-06
Author(s)
Chih-Li Wang
Arkadiusz Malkus
Sabina M. Zuzga
Pi-Fang Linda Chang
Barry M. Cunfer
Edward Arseniuk
Peter P. Ueng
Abstract
Phaeosphaeria species are important causal agents of Stagonospora leaf blotch diseases in cereals. In this study, the nucleotide sequence and deduced polypeptide of the trifunctional histidine biosynthesis gene (his) are used to investigate the phylogenetic relationships and provide molecular identification among cereal Phaeosphaeria species. The full-length sequences of the his gene were obtained by PCR amplification and compared among cereal Phaeosphaeria species. The coding sequence of the his gene in wheat-biotype P. nodorum (PN-w) was 2697 bp. The his genes in barley-biotype P. nodorum (PN-b), two P. avenaria f. sp. triticea isolates (homothallic Pat1 and Pat3), and Phaeosphaeria species from Polish rye and dallis grass were 2694 bp. The his gene in heterothallic isolate Pat2, however, was 2693 bp because the intron had one fewer base. In P. avenaria f. sp. avenaria (Paa), the his gene was only 2670 bp long. The differences in the size of the his gene contributed to the variation in amino acid sequences in the gap region located between the phosphoribosyl-ATP pyrophosphohydrolase and histidinol dehydrogenase sub-domains. Based on nucleotide and deduced amino acid sequences of the his gene, Pat1 was not closely related to either PN-w or the Paa clade. It appears that rates of evolution of the his gene were fast in cereal Phaeosphaeria species. The possible involvement of meiotic recombination in genetic diversity of the his gene in P. nodorum is discussed.
Subjects
barley
wheat
Phaeosphaeria
trifunctional histidine biosynthesis gene
meiotic recombination
Stagonospora leaf blotch
Publisher
Canadian Science Publishing
Type
journal article