Inhibition of Diabrotica Larval Growth by Patatin, the Lipid Acyl Hydrolase from Potato Tubers.

AUTOR(ES)

Strickland, J. A.

RESUMO

Patatin, the nonspecific lipid acyl hydrolase from potato (Solanum tuberosum L.) tubers, dose-dependently inhibits the growth of southern corn rootworm (SCR) and western corn rootworm when fed to them on artificial diet. The 50% growth reduction levels are somewhat cultivar dependent, ranging from 60 to 150 [mu]g/g diet for neonate SCR larvae. A single patatin isoform also inhibits larval growth. Neonate SCR continuously exposed to patatin are halted in larval development. Treatment with di-isopropylfluorophosphate essentially eliminates patatin's phospholipase, galactolipase, and acyl hydrolase activities. SCR growth inhibition is eliminated also, indicating that patatin's serine hydrolase activity is responsible for the observed activities. Patatin-mediated phospholipolysis is highly pH and cultivar dependent, with specific activities up to 300-fold less at pH 5.5 than at pH 8.5. Esterase or phospholipase activities do not correlate with insect growth inhibition. Galactolipase activity, being cultivar and pH independent, correlates significantly with SCR growth inhibition. Insect-growth inhibition of patatin is significantly reduced with increased dietary cholesterol levels. In conclusion, patatin represents a new class of insect-control proteins with a novel mode of action possibly involving lipid metabolism.

Documentos Relacionados

• The two classes of genes for the major potato tuber protein, patatin, are differentially expressed in tubers and roots.
• Sambutoxin, a new mycotoxin produced by toxic Fusarium isolates obtained from rotted potato tubers.
• ADP-Glucose Pyrophosphorylase from Potato Tubers. Site-Directed Mutagenesis Studies of the Regulatory Sites1
• Identification of the major starch synthase in the soluble fraction of potato tubers.
• Biphasic Superoxide Generation in Potato Tubers. A Self-Amplifying Response to Stress1