Nuruzzaman Mohammed, Kanno Tatsuo, Amada Rika, Habu Yoshiki, Kasajima Ichiro, Ishikawa Toshiki, Kawai-Yamada Maki, Uchimiya Hirofumi
Institute for Environmental Science and Technology, Saitama University, Saitama city, Saitama, Japan; Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama, Japan.
Japanese Science and Technology Agency, PRESTO, Saitama, Japan; Plant Genome Engineering Research Unit, Agrogenomics Research Center, National Institute of Agrobiological Sciences, Ibaraki, Japan.
PLoS One. 2014 Sep 26;9(9):e102742. doi: 10.1371/journal.pone.0102742. eCollection 2014.
The genomic nucleotide sequences of japonica rice (Sasanishiki and Nipponbare) contained about 2.7-kb unique region at the point of 0.4-kb upstream of the OsPsbS1 gene. In this study, we found that japonica rice with a few exceptions possessing such DNA sequences [denoted to OsMULE-japonica specific sequence (JSS)] is distinct by the presence of Mutator-like-element (MULE). Such sequence was absent in most of indica cultivars and Oryza glaberrima. In OsMULE-JSS1, we noted the presence of possible target site duplication (TSD; CTTTTCCAG) and about 80-bp terminal inverted repeat (TIR) near TSD. We also found the enhancement ofOsPsbS1 mRNA accumulation by intensified light, which was not associated with the DNA methylation status in OsMULE/JSS. In addition, O. rufipogon, possible ancestor of modern rice cultivars was found to compose PsbS gene of either japonica (minor) or indica (major) type. Transient gene expression assay showed that the japonica type promoter elevated a reporter gene activity than indica type.
粳稻（笹锦和日本晴）的基因组核苷酸序列在OsPsbS1基因上游0.4 kb处含有约2.7 kb的独特区域。在本研究中，我们发现除少数例外，具有此类DNA序列[称为OsMULE-粳稻特异性序列（JSS）]的粳稻因存在类转座子元件（MULE）而有所不同。大多数籼稻品种和光稃稻中不存在此类序列。在OsMULE-JSS1中，我们注意到可能存在靶位点重复（TSD；CTTTTCCAG）以及TSD附近约80 bp的末端反向重复（TIR）。我们还发现强光会增强OsPsbS1 mRNA的积累，这与OsMULE/JSS中的DNA甲基化状态无关。此外，现代水稻品种的可能祖先野生稻被发现含有粳稻类型（少数）或籼稻类型（多数）的PsbS基因。瞬时基因表达分析表明，粳稻类型启动子比籼稻类型启动子能提高报告基因的活性。
