Open AccessDifferential expression of two Blumeria graminis chitin synthase genes
Author(s) -
Zhang Ziguo,
Hall Alison,
Perfect Emma,
Gurr Sarah J.
Publication year - 2000
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1046/j.1364-3703.2000.00015.x
Subject(s) - blumeria graminis , biology , chitin synthase , gene , powdery mildew , chitin , germ tube , population , microbiology and biotechnology , chitinase , genetics , biochemistry , hypha , botany , plant disease resistance , demography , sociology , chitosan
Two Blumeria graminis chitin synthase genes, designated Bg Chs 1 and Bg Chs 2 were cloned and characterized following the synthesis and use of degenerate PCR primers designed to the conserved regions of fungal chitin synthase ( Chs ) genes. Their sequences revealed high similarity with the Chs genes previously cloned from other fungi and placed Bg Chs 1 and Bg Chs 2 with the classes I and V, respectively. Each gene was present as a single copy within the barley powdery mildew genome. Semi‐quantitative RT‐PCR assays revealed Bg Chs 1 to be up‐regulated at both the primary germ tube (PGT) and appressorial germ tube (AGT) stages of differentiation whilst the Bg Chs 2 transcript was up‐regulated at the PGT stage. The B. graminis β‐tubulin gene was used as a control for all RT‐PCR reactions. The Bg Chs 1 transcript was some 30 fold less abundant than the β‐tubulin transcript and Bg Chs 2 was some 30 fold rarer than the Bg Chs 1 transcript. The effects of the chitin substrate analogues nikkomycin Z and polyoxin D on conidial morphogenesis were assessed. These nucleoside peptide inhibitors did not affect germination but both polyoxin D and nikkomycin Z treatment led to a large population of abnormally swollen ‘balloon‐shaped’ AGTs, whilst by 12 h after inoculation polyoxin treatment caused the swollen germ tubes to burst.