Free and Conjugated Indole-3-Acetic Acid in Developing Seeds of Sechium edule Sw.

Abstract

Summary The occurrence and dynamics of free and bound IAA levels in single parts of Sechium edule seeds at various stages of development were investigated. The highest contribution to the whole seed pool is derived from bound IAA and especially from the IAA content of endosperm and teguments. In these tissues a peak in total and bound IAA can be observed coinciding with the phase of rapid seed growth. In the embryo, total and bound IAA levels show a continuous increment during development. On the contrary, the free IAA level, in all the tissues examined, remains at a constantly low level during the whole developmental process. The pattern of free and bound IAA of S. edule developing seeds is different from that observed in other species and is discussed in relation to the viviparity of this cucurbit.