Some Enzymic Activities in the Germinating Oil Palm (Elaeis guineensis) Seedling

Abstract

In germinating oil palm (Elaeis guineensis var D x P) seedling, an active lipase was present in the shoot but absent from both the kernel and the haustorium. It has an optimum pH of 6.2 and a smaller peak at pH 8.6. The shoot lipase was active against a number of mono-, di-, and triacylglycerols as well as the endogenous lipids present in the shoot, haustorium, and kernel. Activity against related substrates were in the order: trilaurin > dilaurin > monolaurin but monopalmitin > dipalmitin > tripalmitin. The level of the enzyme in the seedling was highest at a relatively early stage of growth (18-21 days) and also higher in dark-grown seedlings. Glyoxylate bypass enzymes (malate synthetase and isocitrate lyase), glutamate-oxaloacetate transaminase, phosphoenolpyruvate carboxykinase and lauroyl-coenzyme A oxidase were located in the haustorium. The levels of the enzymes paralleled seedling development and were slightly higher in light-grown seedlings. Fatty acyl-coenzyme A synthetase activity was very low and was found in both the shoot and haustorium.