초록 close

To understand the molecular mechanisms that control seed development, we isolated a seed-preferential gene from ESTs of developing watermelon seeds. The gene Cvsus1 encodes a protein that is 86% identical to the Vicia faba sucrose synthase expressed in developing seeds. RNA blot analysis showed that Cvsus1 was pref-erentially expressed in watermelon seeds. We also in-vestigated gene expression levels both in pollinated seeds and in parthenocarpic seeds, which lack zygotic tissues. Whereas the transcript level of Cvsus1 was rapidly increased during normal seed development, the expression was not significantly increased in the parthenocarpic seeds. However, treating the partheno-carpic fruits with GA3 strongly induced Cvsus1 expres-sion, up to the level accumulated in pollinated seeds. These results suggest that Cvsus1 is induced in mater-nal tissues via signals from the zygotic tissues, and that GA may be one of those signals.