Primers based on a conserved nucleotide binding site (NBS) found in several cloned plant disease resistance genes were used to amplify DNA fragments from the genome of common bean (Phaseolus vulgaris). Cloning and sequence analysis of these fragments uncovered eight unique classes of disease-resistance related sequences. All eight classes contained the conserved kinase 2 motif, and five classes...

Rust fungi (Basidiomycetes of the order Uredinales) are obligate biotrophs that grow and reproduce only in living plant tissue. There are on the order of 5000 or more species of rust fungi that collectively cause disease on most crops, ornamentals, and many other plants. For example, rusts caused by Puccinia species are some of the most important diseases of wheat and other small grain crops wo...