BIOSYNTHESIS, ACCUMULATION AND SECRETION OF ISOFLAVONOIDS DURING GERMINATION AND DEVELOPMENT OF WHITE LUPIN (LUPINUS-ALBUS L)

A combination of C-14 labelling experiments of white lupin seedlings ( Lupinus albus L.) and high pressure liquid chromatography of tissue ex tracts indicated active biosynthesis of isoflavonoids during the first 2-4 d of seed germination. These were synthesized mostly as glucoside s and to a lesser extent as aglycones, with trace amounts of prenylate d derivatives. There was a general decrease in total isoflavonoids dur ing later stages of germination (c. until d 13), which may be ascribed to their turnover and/or exudation into the rhizosphere. In addition, exudation of isoflavonoids by lupin seeds germinated under sterile co nditions continues for 12 d with a preferential release of monoprenyla ted compounds. The relationship between the specific developmental eve nts during seed germination and the accumulation of certain groups of isoflavonoids is discussed in relation to their possible role in the g rowth processes of lupin.