Plant cell wall polysaccharide-degrading enzymes of Melanoplus bivittatus

Abstract

Enzymes in freeze-dried extracts and acetone powder preparations of whole grasshoppers, Melanoplus bivittatus, are capable of degrading hypocotyl cell walls isolated from 5- and 8-day-old red kidney bean plants. Over 40 per cent of the neutral sugars in the cell walls are solubilized by 4 hr incubation with the enzyme preparations. This extraction of cell wall constituents includes 64 per cent of the galactose, 48 per cent of the glucose, and 46 per cent of the arabinose recoverable from untreated walls. The following p-nitrophenyl glycosidase activities are detectable in grasshopper extracts: α- and β-galactosidase, α- and β-glucosidase, β-xylosidase, α-fucosidase, and α-mannosidase. Enzymes are also present which degrade commercial xyland and carboxymethylcellulose. A correlation is made between the ability of the grasshopper enzymes to extract wall polymer and to degrade model substrates.