Project description:Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is one of the most devastating diseases of cruciferous crops worldwide. The pathogen infects and multiplies in plant vascular tissues and, as the disease progresses, the veins of infected tissues turn black and characteristic V-shaped lesions appear along the margins of leaves.The aim of this work is to identify differentially expressed genes from Brassica oleracea during early infection by Xcc, in an attempt to identify proteins related to resistance.
Project description:Xylem sap of young cabbage plantlets was recovered from root pressure exudation and used as a growth medium for the vascular pathogen Xanthomonas campestris pv campestris, the causative agent of the black rot of Brassicaceae.
Project description:Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is one of the most devastating diseases of cruciferous crops worldwide. The pathogen infects and multiplies in plant vascular tissues and, as the disease progresses, the veins of infected tissues turn black and characteristic V-shaped lesions appear along the margins of leaves.The aim of this work is to identify differentially expressed genes from Brassica oleracea during early infection by Xcc, in an attempt to identify proteins related to resistance. Cabbge seedlings were inoculated with Xanthomonas campestris pv campestris (Xcc) suspension and cabbage gene expression at 6h., 24h. And 48h. After inoculation was assessed with help of Brassica 95k EST microarray chip.
Project description:α-Amino ester hydrolases (AEH) are a small class of proteins, which are highly specific for hydrolysis or synthesis of α-amino containing amides and esters including β-lactam antibiotics such as ampicillin, amoxicillin, and cephalexin. A BLAST search revealed the sequence of a putative glutaryl 7-aminocephalosporanic acid (GL-7-ACA) acylase 93% identical to a known AEH from Xanthomonas citri. The gene, termed gaa, was cloned from the genomic DNA of Xanthomonas campestris pv. campestris sp. strain ATCC 33913 and the corresponding protein was expressed into Escherichia coli. The purified protein was able to perform both hydrolysis and synthesis of a variety of α-amino β-lactam antibiotics including (R)-ampicillin and cephalexin, with optimal ampicillin hydrolytic activity at 25 °C and pH 6.8, with kinetic parameters of k(cat) of 72.5 s(-1) and K(M) of 1.1 mM. The synthesis parameters α, β(o), and γ for ampicillin, determined here first for this class of proteins, are α = 0.25, β(o) = 42.8 M(-1), and γ = 0.23, and demonstrate the excellent synthetic potential of these enzymes. An extensive study of site-directed mutations around the binding pocket of X. campestris pv. campestris AEH strongly suggests that mutation of almost any first-shell amino acid residues around the active site leads to inactive enzyme, including Y82, Y175, D207, D208, W209, Y222, and E309, in addition to those residues forming the catalytic triad, S174, H340, and D307.
Project description:An annotated high-quality draft genome sequence for Xanthomonas campestris pv. campestris race 1 strain Xca5 (originally described as X. campestris pv. armoraciae), the causal agent of black rot on Brassicaceae plants, has been determined. This genome sequence is a valuable resource for comparative genomics within the campestris pathovar.
