To identify Arabidopsis mutants that constitutively express systemic acquired resistance (SAR), we constructed reporter lines expressing the firefly luciferase gene under the control of the SAR-inducible PR-1 promoter (PR-1/luc). After EMS mutagenesis of a well-characterized transgenic line, we screened 250,000 M(2) plants for constitutive expression of the reporter gene in vivo. From a mutant ...

There are many naturally occurring variants at the Ml-a locus in barley that confer resistance to the powdery mildew fungus Erysiphe graminis f. sp. hordei. Since the Ml-a locus is bracketed by Hor-1 and Hor-2, genes that encode storage proteins in the endosperm, the Ml-a locus is amenable to fine structure analysis. Rare susceptible recombinants, as judged by exchange of flanking markers, were...

The plant genes required for the growth and reproduction of plant pathogens are largely unknown. In an effort to identify these genes, we isolated Arabidopsis mutants that do not support the normal growth of the powdery mildew pathogen Erysiphe cichoracearum . Here, we report on the cloning and characterization of one of these genes, PMR6 . PMR6 encodes a pectate lyase–like protein with a novel...

genus polymyxa, belongs to plasmodiophoromycota phyllum and protozoa kingdom. this fungus is a obligate endoparasite in the root cells of vascular plants. since the two species of this genus, p. graminis and p. betae are both known to carry destructive viral agents to sugar beet and poaceae. for studying the distribution of infected fields with p. betae in razavi and northern khorasan provinces...