Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) V. Ontogenetic change

Abstract

On plants of the same age, differences between leaves in the concentrations of the oestrogenic isoflavones daidzein (D), formononetin (F), genistein (G), and biochanin A (BA) were largely due to differences in leaf age. Concentrations of F, G, and BA declined during unfolding and development of the individual leaf. The maximum amounts per leaf of F, G, and BA were attained at the completion of the cell expansion stage. The appearance of D was associated with leaf senescence.

The concentrations of F, G, and BA in expanded leaves usually declined during plant growth. An exception was F in the Yarloop strain.

Relatively low levels of isoflavones were found in the stem + petiole fraction and in the roots, and intermediate levels in flowers.

The relevance of these results to animal bioassays for oestrogenic activity is discussed.