| Summary: | 碩士 === 國立中興大學 === 分子生物學研究所 === 90 === Abstract
Promoters of two rice embryo-specific genes Ose730 and Ose721 were investigated in this study. Ose730 is a gene encoding a group 3 late embryogenesis abundant protein and Ose721 is a gene encoding the 18 kD oleosin. Four transgenic rice YJ1, YJ2, YJ3 and YJ1C, with various length 3.1, 2.2, 0.8 and 0.17 kb of Ose730 promoter region fused to GUS reporter gene, respectively, were obtained. In addition, six other constructs (D3 to D8) with promoter length between 2.2 and 0.8 kb have also been obtained. The histochemical assays of GUS activity indicated that transgenic rice YJ1 has its GUS expressed specifically in embryo and alurone layer, while the transgenic rice YJ3 and YJ1C have their GUS expressed in all the tested tissues including seeds, leaves, glumes and anthers. This result suggested that the sequences further upstream from 0.8 kb involved in embryo-specific expression. It has also been observed that the level of GUS expression in seedling increased about 10 folds as compare YJ3 (0.8 kb) to D5 (1.3 kb). These observations suggested that a down regulation element existed between 1.3 and 0.8 kb upstream from the transcription initiation site. Results of ABA induction in rice seedling indicated that a region between 1.3 and 2.2 kb may contained ABA responsive element.
Transgenic rice 721-F, 721-St and 721-Xb with various length (1256, 1034 and 391 bp) of Ose721 promoter region, respectively, were under investigation too. Each tested transgenic line contained a copy of the GUS gene as shown in Southern assays. Only few GUS activities were detected in leaves and glumes for these Ose721 promoter-driven transgenic rice plants. There was no GUS activity observed in anthers either before or after pollination in transgenic rice 721-F and 721-St, while GUS activity was observed in anthers after pollination in transgenic rice 721-Xb.
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