Study on aroma related genes in rice（Oryza sativa L.）Tainung 67 and its aromatic mutant, SA0420.
| Autor: | Shu-Ming Kuo, 郭淑明 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 Rice is an important staple food in the world aroma is one of its important traits providing higher value. The purpose of this thesis is to study the aromatic phenotype and to clone the related genes in order to improve rice eating quality. Rice cultivar Tainung 67 (TNG67) and its sodium azide induced mutants were used for experiments. A mutant, SA0420, produces aroma in leaves and grains at various stages of development and is conditioned by a single dominant locus that differs from most of the aroma rice varieties which were recessive traits. Our sequencing results showed that the aroma of SA0420 is not controlled by the betaine aldehyde dehydrogenase (BAD2) gene as reported by Bradbury et al. (2005). Besides, the aroma of variety TNG71 and the aromatic mutants, SA0418 and SA1613 of TNG67 mutation pool are not controlled by the BAD2 gene, either. Our proteomic studies discovered that two differentially expressed proteins glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glutamate-1-semialdehyde-2,1-amino- transferase (GSA-AT) may closely related to the aroma production (Chou, 2004). Sequences of rice GAPDH and GSA-AT genes were firstly obtained by bioinformatic approach, cloned and sequenced by PCR technology. A total of 7 GAPDH genes are found in the rice genome and named as GAPDH1 to GAPDH7 for the first time in this thesis. The GAPDH7 and GSA-AT genes are located very close to the RG1 SSR marker on the chromosome 8, which was previously reported to be linked to the aroma trait. Because the aroma produced in rice is in a quantitative but not a qualitative manner no significant difference was detected in the expression of GAPDH2 (XM_493811) and GSA-AT (XM_507903) in leaves of TNG67 and SA0420 by RT-PCR. Both GAPDH2 and GSA-AT genes are expressed at very low to none levels in rice grains as compared with those of leaves, providing an evidence for our previous hypothesis that the aroma of SA0420 mutant is mainly produced in leaves then translocate to grains during grain filling period (C. S. Wang unpublished data). Sequences analyses of GAPDH1 and GAPDH2 showed that mutations occurred in the GapA domain of GAPDH1, GAPDH2 may affect the structure and activity of proteins. The lack of two GAPDH proteins in SA0420 mutant could be a key factor to increase its aroma synthesis. The clear grouping by phylogenetic analyses of the GSA-AT sequences from 17 fragrant and 7 non-fragrant rice varieties also provides the evidence that the GSA-AT is related to the aroma of SA0420. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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