Cloning and Characterization of Avr1 Gene From Puccinia Triticina.

Leaf rust is the most common and one of the most important cereal diseases of the world.   Current leaf rust control has consisted of breeding for resistant cultivars by identifying Lr genes in the host.  These cultivars quickly become susceptible to infection due to the tremendous extant genetic diversity of the pathogen that allows it to overcome resistant cultivars in 2-4 years.   Developments of alternate methods of control are limited since little is known about Puccinia’s genome and plant-pathogen interaction. Construction of a genome-wide physical map is important in order to fully understand the infection mechanism of the pathogen and its interaction with the host.  In an effort to discover more about the genetic potential of leaf rust in terms of AVR and VIR gene regulation and create novel plant resistance breeding strategies in the future, we have proposed a study of the pathogen’s genome by constructing a BIBAC library and a physical map of the pathogen.   The BIBAC library is being constructed from pathotype PRTUS 3 which has AVR-1 disrupted using T-DNA mutagenesis via particle bombardment.   The characterization of the AVR-1 in the BIBAC library will serve as a point of reference for cloning heterologous AVR and VIR genes, and defining their regulation and mode of inheritance and recombination.