EXPRESSION OF VEGETATIVE STORAGE PROTEIN (VSP-BETA) IN SOYBEAN RACEMETISSUES IN RESPONSE TO FLOWER SET

Abortion of flowers and pods (> 25%) appears to be part of the normal developmental sequence in Glycine max [L.] Merr. Slow growth rates of seeds and pods, and development of an abscission zone in raceme tissue s subtending flowers destined to abort contribute to this loss, but th e processes leading to these events have not been elucidated. Rescue o f soybean flowers destined to abort was accomplished by removal of pro ximal flowers and/or application of 1 mM benzyladenine (BA) before ant hesis. Raceme tissues (axes and pedicels, including the abscission zon e) subtending setting and aborting flowers were examined for different ial protein expression to identify gene products that were directly as sociated with the induction of flower set. Induction to set was associ ated with increased protein concentrations, Transcription and translat ion of a soybean vegetative storage protein (VSP-beta) in the subtendi ng raceme tissues was directly linked to flower set. Cytokinin applica tion increased growth of raceme tissues independent of fruit set. A mo del system for future studies of regulation of soybean flower set and abortion is presented.