Dr. Clouse is requesting funds to conduct a one year pilotprogram on the effects of a novel plant growth steroid,brassinolide (BR), on gene expression during development. He hason hand the chemically pure compound, a set of molecular probesand transgenic plants and three assay systems with which toobtain, within one year, definitive answers about thefeasibility of establishing a long.term program on the action ofthis steroid compound on the transcription of plant genesinvolved in growth and differentiation. No work on the action ofthis compound on gene transcription has been reported and thelack of preliminary molecular data make this unsuitable for afull scale proposal. BR has pronounced effects on plant growthand development, interacts with other plant growth regulators andshares structural similarities with animal steroid hormones. Ithas immense potential as a tool for probing gene expressionduring development and as an agricultural growth promoter. %%% Nothing is known about the mechanism of action of brassinolide. This pilot study will determine if it has a proximal effect ongene expression. If so then a larger research effort would bewarranted.