Fine Mapping And Cloning Of The Rice Elongated Uppermost Internode Gene EUI2(t) | Posted on:2004-09-09 | Degree:Doctor | Type:Dissertation | Country:China | Candidate:H B Zhu | Full Text:PDF | GTID:1103360125954650 | Subject:Crop Genetics and Breeding | Abstract/Summary: | PDF Full Text Request | The gene eui (elongated uppermost internode ) is one of the most important genes deployed in hyhrid rice breeding, since it has been used to improve panicle exsertion of rice male-sterile lines. The gene eui2(t) is a newly found one for it is nonallelic to the eui gene reported by JN Rutger before. And the gene have been mapped onto the middle of the long arm of the rice chromosome 10 by SL Yang.Using F2 population developed from the cross between Xieqingzao eB2 and Zhonghua 14(a japonica line), we locted EUI2(t) gene in an interval of 41.7-kbDNA fragment between the two new SSR markers. We also attempted to identify the gene by comparing the sequences of the allelic mutants with those of the wild type rice, and confirm the ORF of the gene by RT-PCR. The main results of this research are as follows:1003 individuals showing the eui2(t) phenotype from -8000 F2 plants were used for fine-mapping and the EUI2(t) gene was mapped in a 41.7-kb DNA fragment of a BAC (ACO68923) between the RZH37 and RZH25 markers. At the same time the marker RZH38 was identified as a co-segregating marker with EUI2(t) locus. Within the region,only 10 predicted genes were predicted, but none of them was annotated as the gene relating to stem elongating in plants.We designed primer pairs to amplify the 4 predited genes near the co-segregating marker RZH38 from the 4 independent eui2(t) mutants. Sequencing of these fragments and comparison with their wild-type sequences identified a deletion (one or six bp) in the putative gene (GB: AAB02006 GI: 1354849) of every mutants, and found all the deletions were in the exon regions. So we concluded that this putative gene was the EUI2(t) gene (new GeneBank ID: AY319965). The ORF of this gene have 933 bp with 5 exons (31573-33148 on BAC ACO68923) encoding 311 amino acids.Using RT-PCR with gene-spectific primers, cDNA were amplified from the uppermost internode RNA of XQZB (wild type) and XQZeB2 (eui2(t) mutant) The EUI2(t) gene strongly expressed in the uppermost internode of XQZB, and the sequnce of the cDNA was identical to the predicted ORF of the gene.The putative protein of this ORF shows homology (52% identity) to the tobacco EH1(soluble epoxide hydrolase) from the tobacco leaves infected by tobacco mosaic virus (TMV). There is less documented function for the soluble epoxide hydrolase in plant and it could play a role in metabolization of the epoxy acids.According to the former research progress of Prof. Yang's group, there are more accumulation of GA1 (gebberellin acids) in the panicles, uppermost internode and flag leaves of the mutant than that of the wild type rice, we suggested that the enzyme encoded by EUI2(t) gene relate to the catabolism of gebberellin acids. | Keywords/Search Tags: | O.Sativa L., EUI2(t), fine mapping, gene cloning | PDF Full Text Request | Related items |
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