UC Irvine

The major portion of IAA-2-14C, applied to stigmas of whole flowers of Angraecum cv. Veitchii and Cattleya cv. Porcia Cannizaro, as well as to excised gynostemia of the latter, was immobilized at the point of application. A limited amount of nonpolar transport occurred. Some of the auxin was conjugated into IAA-aspartate in a process which is inhibited by cycloheximide, suggesting a requirement for de novo protein synthesis. Because the effects of pollination and auxin application spread quickly to floral segments, additional substances, from pollen or produced by pollinated flowers, may participate in the regulation of postpollination phenomena in orchid flowers.