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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #124430
Title: EVOLUTION OF A PLANT-DEFENSE GENE CLUSTER

Author
item WEI, FUSHENG - ISU
item WING, ROD - CLEMSON UNIVERSITY
item Wise, Roger

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/14/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The barley Mla (powdery mildew) resistance cluster contains one of the highest degrees of variability among all plant-disease resistance loci. The primary structure of the 261-kb barley Mla region encompasses thirty-two protein-encoding genes and two tRNApro genes. Notably, sixteen of these genes are plant-defense related; 12 of these 16 are associated with defense against powdery mildew disease, but function in different signaling pathways. These defense related and other protein-encoding sequences are organized as three gene-rich islands separated by two 40-kb complexes of nested transposons and a gene-poor region. Our results indicate that defense-related genes tend to cluster together and that the present Mla region evolved over a period of approximately 7 million years through a series of duplication and inversion events in addition to nested transposable element insertion. We present a model for the evolution of the Mla region, which reveals some emerging features of large cereal genomes.