Establisment of rice library is an essential approach for rice functional genomics study. Utilizaing maize transposable element Ac/Ds is a promising method to construct insertional mutagenesis library of rice. Ac/Ds tagging system has received extensive application in rice during the past several years. The maize Ds element is one of the main tagging vehicles used in rice. Narrow leaf mutant have short height, narrow leaf width and large angle. To compare with wild type and narrow leaf mutant in detail, we observed the leaves under microscope. In specific portion(large and small vein), no significantly reduce cell size and number of cell. Knock-out of the OsNLR(narrow leaf ribokinase) gene inhibits internodes, panicles, angle(between leaf and stem), leaf, seed. OsNLR was shown to specifically expressed on leaf. In real time PCR analysis with mature leaf of wild type and mutant, there might be a functional association between OsAGO7, NRL1, NAL1 and NAL7 in regulating leaf development. We tested on the experimental field using wild type and mutant plants. In agricutural traits that contain leaf and seed related traits(except angle) significantly reduce in mutant plants. These results demonstrate that OsNLR gene may be associated with leaf development.

R2R3 MYB transcription factors play regulatory roles in plant responses to various environmental stresses and nutrient deficiency. In this study, we isolated MYB-like gene respond to phosphorus deprivation in rice and designated OsMYB4P, an R2R3 MYB transcription factor, from rice under low-phosphate conditions. OsMYB4P is 993bp long and encodes a 330 amino acid polypeptide. OsMYB4P was localized in the nucleus and acted as a transcriptional activator. Transcriptional levels of OsMYB4P in cell suspension, shoots, and roots of rice increased under low phosphate conditions. Shoots and roots of OsMYB4P overexpressing plants grew well in high and low phosphate conditions. In addition, root system architecture was altered considerably as a result of OsMYB4P overexpression. Under both phosphate sufficient and deficient conditions, more Pi accumulated in shoots and roots of OsMYB4P overexpressing plants than in the wild type. Overexpression of OsMYB4P led to greater expression of Pi transporter-family proteins OsPT1, OsPT2, OsPT4, OsPT7, and OsPT8 in shoots, and to decreased or unchanged expression of these proteins in roots, with the exception of OsPT8. These results demonstrate that OsMYB4P may be associated with efficient utilization of Pi in rice.

We used an efficient system to create rice mutant by Ac/Ds transposon insertion mutagenesis, such as selected homozygous mutant in dwarf phenotypes. We reported here the identification of function of dwarf OsGASD gene(Oryza sativa Gibberellin Acid Sensitive Dwarf). OsGASD gene encodes a 344 amino acid polypeptide and no homology proteins in Gene Bank. The osgasd mutnat was sensitive to exogenous gibberellic acid(GA) level. We performed experiment to controlled expression the OsGASD gene, its role in plant development, a quantitative analysis of endogenous GA content and sensitivity to GA. The osgasd mutant includes smaller amount of active GAs than wild-type. osgasd mutant plant of GA biosynthesis pathway causes GA deficiency and dwarf plants, and endogenous GA suppliance can restore the wild type phenotype in this mutant. There result indicated that OsGASD gene regulated the elongation of shoot, stem and plant height. The increased expression of OsGASD gene dramatically induces expression of the factors associated with GA biosynthesis, whereas osgasd mutant suppression of the factors associated with GA biosynthesis, loading to dwarf phenotypes. That applied GA3 at the plant development stage to survey the response of OsGASD gene to GA3. We suggest that OsGASD gene is related to factors of GA biosynthesis pathway regulating rice internodes development.

The ubiquitin-26S proteasome system is important in the quality control of intracellular proteins. The ubiquitin-26S proteasome system includes the E1 (ubiquitin activating), E2 (ubiquitin conjugating) and E3 (ubiquitin ligase) enzymes. U-box proteins are a derived version of RING-finger domains, which have E3 enzyme activity. Here, we present the isolation of a novel U-box protein, OsUPS, from rice (Oryza sativa).The cDNA encoding the O.sativa U-box protein(OsUPS) comprises 1338bp, with an open reading frame of 445 amino acids. The open reading frame of the OsUPS protein is comprised of notable domains: a single ~70-amino acid domain and a GKL domain that contains conserved glycine, lysine/ arginine residues and leucine-rich feature. 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. Suppression of OsUPS resulted in servre signs of toxicity caused by the over-accumulation of Pi. These results support the notion that OsUPS plays an important role in the Pi signaling pathway through the ubiquitin-26S proteasome system.

Fibroin silk proteins from spider or silkworm are attractive biomaterials that are of particular biotechnological interest for industrial and medical purposes because of their unique physical and mechanical properties. In this study, we generated and characterized the transgenic rice plant expressing a spider silk protein. Spider silks have great potential as biomaterials with extraordinary properties. Here, we report the cloning and characterization of the major ampullate silk protein gene from the spider Araneus ventricosus. A cDNA encoding the partial major ampullate silk protein (AvMaSp) was cloned from A. ventricosus. An analysis of the cDNA sequence shows that AvMaSp consists of a 240 amino acid repetitive region and a 99 amino acid C-terminal non-repetitive domain. The peptide motifs that were found in the spider major ampullate silk proteins, (A)n, (GA)n, and (GGX)n, were conserved in the repetitive region of AvMaSp. Phylogenetic analysis further confirmed that AvMaSp belongs to the spider major ampullate spidroin family of proteins. Recombinant AvMaSp-R was degraded abruptly by trypsin. However, AvMaSp-R was stable at 100 °C for at least 30 min. Additionally, the AvMaSp-R was stable at pH values from 2 to 12 for at least 1 h. Taken together, our findings describe the molecular structure and biochemical properties of the A. ventricosus major ampullate silk protein and demonstrate its potential as a biomaterial.

The molecuar prossing of upsteam regulation of Pi response genes during Pi starvation remains inadequately understood. R2R3 MYB transcription factors play regulatory roles in plant responses to various environmental stresses and nutrient deficiency. In this study, we isolated and designated OsMYB4P, an R2R3 MYB transcription factor, from rice under low-phosphate conditions. OsMYB4P was localized in the nucleus and acted as a transcriptional activator. Transcriptional levels of OsMYB4P in cell suspension, shoots, and roots of rice increased under low phosphate conditions. To investigate the function of OsMYB4P in Pi-starvation signaling, we developed transgenic rice plants overexpressing OsMYB4P for analysis of Pi signaling and uptake. Shoots and roots of OsMYB4P overexpressing plants grew well in high and low phosphate conditions. In addition, root system architecture was altered considerably as a result of OsMYB4P overexpression. Under both phosphate sufficient and deficient conditions, more Pi accumulated in shoots and roots of OsMYB4P overexpressing plants than in the wild type. Overexpression of OsMYB4P led to greater expression of Pi transporter-family proteins OsPT1, OsPT2, OsPT4, OsPT7, and OsPT8 in shoots, and to decreased or unchanged expression of these proteins in roots, with the exception of OsPT8. These results demonstrate that OsMYB4P lead to Pi accumulation and acts as a Pi-dependent regulator in controlling the expression of Pi transporters.

In this study, we generated and characterized the transgenic rice plant expressing a spider silk protein. Spider silks have great potential as biomaterials with extraordinary properties. We report the cloning and characterization of the major ampullate silk protein gene from the spider Araneus ventricosus. A cDNA encoding the partial major ampullate silk protein (AvMaSp) was cloned from A. ventricosus. An analysis of the cDNA sequence shows that AvMaSp consists of a 240 amino acid repetitive region and a 99 amino acid C-terminal non-repetitive domain. The peptide motifs that were found in the spider major ampullate silk proteins, (A)n, (GA)n, and (GGX)n, were conserved in the repetitive region of AvMaSp. Phylogenetic analysis further confirmed that AvMaSp belongs to the spider major ampullate spidroin family of proteins. The AvMaSp-R cDNA, which encodes the 240 amino acid repetitive domain, was expressed as a soluble 22 kDa polypeptide in baculovirus-infected insect cells. To produce transgenic rice plant with high contents of glycine and alanine, the prolamin promoter-driven AvDrag was introduced into rice plant via agrobacterium tumefaciens-mediated gene transformation. The introduction and copy number of the AvDrag gene in transgenic rice plants were determined by PCR and Southern blot analysis. AvDrag expression in transgenic rice seeds was examined by Northern blot and Western blot analysis. Immunofluorescence staining with the AvDrag antiserum revealed that the recombinant AvDrag protein were localized in transgenic rice seed. Furthermore, the amino acid content analysis showed that transgenic rice seeds were greatly increased in glycine and alanine as compared to controls

We used an efficient system to create rice mutant by Ac/Ds transposon insertion mutagenesis, such as selected homozygous mutant in dwarf phenotypes. We reported here the identification of function of dwarf OsGASD gene(Oryza sativa Gibberellin Acid Sensitive Dwarf). OsGASD gene encodes a 344 amino acid polypeptide and no homology proteins in GeneBank. The osgasd mutnat was sensitive to exogenous GA level. We performed experiment to controlled expression the OsGASD gene, its role in plant development, a quantitative analysis of endogenous GA content and sensitivity to GA. The osgasd mutant includes smaller amount of active GAs than wild-type. osgasd mutant plant of GA biosynthesis pathway causes GA deficiency and dwarf plants, and endogenous GA suppliance can restore the wild type phenotype in this mutant. There sult indicated that OsGASD gene regulated the elongation of shoot, stem and plant height. The increased expression of OsGASD gene dramatically induces expression of the factors associated with GA biosynthesis such as CPS, KO, KAO, GA 20 ox and GA 2 ox, whereas osgasd mutant suppression of the factors associated with GA biosynthesis, loading to dwarf phenotypes. That applied GA3 at the plant development stage to survey the response of OsGASD gene to GA3. These results indicated that OsGASD gene is involved in GA biosynthesis factors, not only in the internodes, but also leaf length at the developing stage.

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.