Note: Phenylalanine ammonia lyase activity in tomato seedlings and its relationship to bacterial canker disease resistance

Phenylalanine ammonia lyase (PAL) activity was studied in different genotypes of tomato with varying degrees of resistance and susceptibility to bacterial canker disease after inoculation withClavibacter michiganensis ssp.michiganensis. In resistant genotypes the enzyme activity increased significantly 21 h after bacterial inoculation, whereas in the susceptible genotypes the activity decreased. The increase or decrease in PAL activity correlated well with the degree of host resistance along with total phenol contents. The role of PAL in imparting resistance to tomato against bacterial canker disease is discussed. http://www.phytoparasitica.org posting Nov. 14, 2005.