Lignification as a Mechanism of Disease Resistance

This review deals with the formation of lignin as a mechanism of resistance to plant disease. Lignin is one of the most abundant biopo1ymers on earth (120, 140) and is resistant to degradation by most microorganisms (83,84). It is thought to be formed commonly as a response to microbial penetration and mechanical damage (51, 71, 111, 140), but the role of lignification in disease resistance has been investigated in only a limited number of cases. The possible specificity of lignin formation in disease resistance remains unresolved.