报告题目: Development of mineral enhanced rice
报 告 人: Prof. Gynheung An
Kyung Hee University
Crop Biotech Institute
Giheung 446-701, Republic of Korea
Flower Development in rice
Flowering plants complete their life cycle by shifting from vegetative to reproductive growth. In order to understand the early stage development of the reproductive organs, we have been working on regulatory genes that may be involved in controlling flower or fruit formation.
It has been well established that a group of regulatory genes controls flower development. In order to understand roles of these regulatory genes in monocot plants, we have been studying the MADS box genes from rice. We have shown that there are a group of MADS box genes that are involved in controlling flowering time and organ development. Ectopic expression of several MADS box genes resulted in early flowering, suggesting that some MADS box genes are involved in controlling flowering time. In addition, these MADS box genes pay an important role in organ developmetn. For example, the leafy hull (lhs) mutant that is defective in palea and lemma development is due point mutations within the MADS box of OsMADS1.
T-DNA tagging of rice genome
There has been much progress in the development of strategies to discover the function of plant genes. The development of the strategies has been largely based on genetic approaches such as mutant identification and map-based gene isolation. Gene inactivation by insertion of a transposon has been employed for functional studies in several plant species. The use of T-DNA as a mutagen has also been developed for tagging genes in Arabidopsis. It is believed that T-DNA insertion is a random event, and that the inserted genes are stable through multiple generations. We have generated over 30,000 T-DNA tagged lines of rice. The binary vector used in the insertion contained the promoterless gus reporter gene, allowing detection of a gene fusion between gus and an endogenous gene, which is tagged by T-DNA. The data revealed that at least 5% of the lines are GUS positive. The large population of T-DNA tagged lines is used for identifying insertional mutants in various genes and for discovering new genes in rice.