Rice is a staple food crop in the world. A number of agronomically important traits including enhancement of stress tolerance, quality improvement, and nutrition value increases have been introduced to rice. In this study, an Oryza sativa cDNA containing a U-box motif was cloned; its deduced amino acid sequence was compared to that of other U-box genes and indicated that encodes a U-box-containing E3 ligase. E3 ligases are structurally divided into three groups. We isolated the OsUPS gene from rice (Oryza sativa). The OsUPS protein has domain which is a single~70-amino acid region of the protein and GKL domain containing conserved Glycine, Lysine/ Araginine residues and leucine-rich feature. A full-length expression of OsUPS was up-regulated in the rice plant and in cell culture in the absence of phosphate. To express the OsUPS cDNA, it was inserted into the pGEX-2T vector. And the gene was expressed in E.coli strain BL21 (DE3). Induced after 3h of IPTG treatment and was isolated by affinity chromatography. Using the GUS reporter genes regulated by the OsUPS promoter, we have carried out the analysis of transcriptional and spatial regulation of gene expression. To investigate the function of these genes, the CaMV 35S promoter-driven these genes were introduced into Arabidopsis and rice via Agrobacterium tumefaciens-mediated gene transformation. We found that full-length expression of OsUPS was up-regulated in both rice plants and cell culture in the absence of inorganic phosphate (Pi). A self-ubiquitination assay indicated that the bacterially expressed OsUPS protein had E3 ligase activity, and subcellular localization results showed that OsUPS was located in the chloroplast. These results support the notion that OsUPS plays an important role in the Pi signaling pathway through the ubiquitin-26S proteasome system.

Rice is not only a model plant of monocots but also one of the most important crops all over the world. Despite the importance of leaf shape for achieving effective plant architecture for photosynthesis, little is known about the genetic mechanisms that determine leaf morphological characteristics. Explanation of the genetic basis of the control of leaf shape could be of use in the manipulation of crop traits, leading to increased crop production. Many mutants related to leaf morphology have been identified and classified according to their function in determining leaf morphology. search on the genetics of leaf development has used mutagensis to create loss-of-function mutations that change leaf shape. To understand the molecular mechanism of leaf morphogenesis, we identified a rice mutant gene, which was characterized by a phenotype of narrow leaves. While the mutation resulted in reduced leaf width, no significant morphological changes at the cellular level in leaves were observed, except in bulliform cells. The gene locus guess that it encodes a adenosine kinase, which displays sequence homology with ribokinase pfkB like superfamily. To test function of gene, we cloned gene which have 1140 nucleotides and 379 amino acids. This gene was transcribed in various tissues and was mainly expressed in panicles and leaves. NAL7, NAL1 and SLL1 were found to be downregulated, whereas OsAGO7 and NRL1 were upregulated in the mutant. These findings suggested that there might be a functional association between these genes in regulating leaf development.