The proposed work will lead to the characterization of cellulase genes, cellulase proteins, and a test of their role in the infection of higher plants by the N2-fixing symbiont, Frankia. Two endoglucanase genes have been isolated. Additional genes will be sought, and their molecular structure determined through DNA sequencing, to identify any unique characteristics that enable functioning in symbiosis. Endoglucanase proteins will be overexpressed in E. coli, or S. aureus, purified, and used to raise antibodies for immunocytochemical localization during infection. The results will allow conclusions to be drawn about molecular interactions that occur during infection and root nodule development in actinorhizal plants. If gene replacement or disruption attempts are successful for eliminating endoglucanase from Frankia, mutants will be tested for their ability to infect and establish a symbiosis, and such mutants will be the first demonstration of genetic manipulation in these important organisms. In addition, novel cellulases will become available to be evaluated for their practical development in biomass conversions.***//
