Inducible versus constitutive PI 227687 soybean resistance to mexican bean beetle,Epilachna varivestis.

Contrary to constitutive resistance, inducible resistance to Mexican bean beetle (MBB) (Epilachna varivestis) herbivory in PI 227687 soybean leaves was positively correlated with total phenolic content and temporally unique, increasedL-phenylalanine ammonia-lyase (PAL) andL-tyrosine ammonia-lyase (TAL) activities. Initial expression of the induced resistance was localized at or near the site of herbivory. Systemic parameters of the induced resistance also were observed. Inducible MBB resistance in PI 227687 soybeans apparently involves increased phenylpropanoid metabolism.