Rice functional genomics study with T-DNA insertion mutants—Characterization and gene expression analysis of a disease susceptible mutant M0023454 and a seed development mutant M0039314

• Main Authors: Yan-Suan Li, 李彥璇
• Other Authors: Liang-Jwu.J. Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/13266446060857175347

碩士 === 國立中興大學 === 分子生物學研究所 === 94 === In this study, 12 T-DNA insertion mutant lines were selected by their distinct phenotypes in grain development such as sterile, low fertility, abnormal panicles and grains. Only six of these mutants could get flanking sequence by TAIL PCR and plasmid rescue. Among them, only mutants M0023454 and M0039314 showed single insertion event without changes of Tos17 number in their genomes. They were selected for further study. In mutant M0023454, the T-DNA was inserted in the BAC clone of OSJNBa0039C07 in the rice chromosome number 4. This mutant showed more susceptible to the pathogen, and this phenotype was co-segregated with the genotype. The expression of gene 454-10, 987 bp upstream of T-DNA insertion site, was activated in mutant while no expression was detected in TNG67. Gene 454-10, encode an AP2 domain, is belong to the AP2/ERF family and much more similar to ERFBP group, which involved in pathogen resistant pathway. This study suggests that the susceptible phenotype to pathogen in mutant M0023454 may be due to the overexpression of gene 454-10. In mutant M0039314, the T-DNA was inserted in the PAC clone of P0702E04 in the rice chromosome number 8. Mutant M0039314 showed abnormal phenotypes, such as dark green leaves, irradiative tillers, low fertility, incomplete seed development, weaker anthers and reduced length of panicle and peduncle. Almost all of these abnormal phenotypes were co-segregated with the genotypes. The expression of gene 314-5 and 314-6, flanked at both side of T-DNA inserted site, were activated in mutant M0039314 while no expression was detected in TNG67. Gene 314-5 encodes a putative transcription factor, SBP, and expressed weakly in all vegetative tissues but strongly in the reproductive tissues in TNG67. Gene 314-6, an OsMADS45 gene, has been published and showed mainly expressed in the reproductive tissues in TNG67. The results of this study suggest that the abnormal phenotypes in mutant M0039314 may be due to the overexpression of gene 314-5 and 314-6. In order to confirm the abnormal phenotypes of M0023454 and M0039314 are really caused by the overexpression of 454-10, 314-5 and 314-6 and to find out the exact function of these genes, the transgenic lines with overexpression of these genes will be created.