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Transgenic Rice (transgenic + rice)
Terms modified by Transgenic Rice Selected AbstractsIncreased Susceptibility of Rice Following Insertion of Amylopullulanase Gene, to Brown Spot Caused by Bipolaris oryzaeJOURNAL OF PHYTOPATHOLOGY, Issue 9 2008M.-Y. Ting Abstract Transgenic rice expressing an amylopullulanase (APU) from the bacterium Thermoanaerobacter ethanolicus 39E produces grains which are less expensive to process for production of sugar syrup and protein-enriched flour. During risk assessment of the transgenic line in a field test, brown spot disease caused by Bipolaris oryzae was found more severe on the transgenic line APU than on its parental line TNG67. When lines APU and TNG67 were inoculated at seedling, tillering or heading stage with B. oryzae isolated from line TNG67, the disease was more severe on line APU than on line TNG67 at heading stage, but not at the seedling or tillering stage. However, when B. oryzae isolated from line APU was used in the inoculation tests, the disease was more severe on line APU than on line TNG67 at seedling stage, but not at the tillering or heading stage. To our knowledge, this is the first report of an unintended change in a transgenic plant to become more susceptible to a disease than the non-transgenic plant. [source] Construction and Application of Efficient Ac-Ds Transposon Tagging Vectors in RiceJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 11 2009Shaohong Qu Abstract Transposons are effective mutagens alternative to T-DNA for the generation of insertional mutants in many plant species including those whose transformation is inefficient. The current strategies of transposon tagging are usually slow and labor-intensive and yield low frequency of tagged lines. We have constructed a series of transposon tagging vectors based on three approaches: (i) AcTPase controlled by glucocorticoid binding domain/VP16 acidic activation domain/Gal4 DNA-binding domain (GVG) chemical-inducible expression system; (ii) deletion of AcTPase via Cre- lox site-specific recombination that was initially triggered by Ds excision; and (iii) suppression of early transposition events in transformed rice callus through a dual-functional hygromycin resistance gene in a novel Ds element (HPT-Ds). We tested these vectors in transgenic rice and characterized the transposition events. Our results showed that these vectors are useful resources for functional genomics of rice and other crop plants. The vectors are freely available for the community. [source] Development of insect-resistant transgenic rice with Cry1C*-free endospermPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2009Rongjian Ye Abstract BACKGROUND: Yellow stem borer (Tryporyza incertulas Walker), striped stem borer (Chilo suppressalis Walker) and leaf folder (Cnaphalocrocis medinalis Guenec) are three lepidopteran pests that cause severe damage to rice in many areas of the world. In this study, novel insect-resistant transgenic rice was developed in which Bt protein expression was nearly absent in the endosperm. The resistant gene, cry1C*, driven by the rice rbcS promoter (small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase), was introduced into Zhonghua 11 (Oryza sativa L. ssp. japonica) by Agrobacterium -mediated transformation. RESULTS: A total of 83 independent transformants were obtained, 19 of which were characterised as single-copy foreign gene insertion. After preliminary screening of the T1 families of these 19 transformants in the field, six highly insect-resistant homozygous lines were selected. These six homozygous transgenic lines were field tested for resistance to leaf folders and stem borers, and for their agronomic performance. The Cry1C* protein levels in leaves and endosperm were measured by ELISA. Subsequently, the elite transgenic line RJ5 was selected; this line not only possessed high resistance to leaf folders and stem borers, normal agronomic performance, but also Cry1C* expression was only 2.6 ng g,1 in the endosperm. CONCLUSION: These results indicated that RJ5 has the potential for widespread utility in rice production. Copyright © 2009 Society of Chemical Industry [source] Generation of stable ,low phytic acid' transgenic rice through antisense repression of the 1d - myo -inositol 3-phosphate synthase gene (RINO1) using the 18-kDa oleosin promoterPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2009Mio Kuwano Summary Phytic acid acts as the major storage form of phosphorus in plant seeds and is poorly digested by monogastric animals. The degradation of phytic acid in animal diets is necessary to overcome both environmental and nutritional issues. The enzyme 1d - myo -inositol 3-phosphate [Ins(3)P1] synthase (EC 5.5.1.4) catalyses the first step of myo -inositol biosynthesis and directs phytic acid biosynthesis in seeds. The rice Ins(3)P1 synthase gene (RINO1) is highly expressed in developing seed embryos and in the aleurone layer, where phytic acid is synthesized and stored. In rice seeds, 18-kDa oleosin (Ole18) is expressed in a seed-specific manner, and its transcripts are restricted to the embryo and the aleurone layer. Therefore, to effectively suppress phytic acid biosynthesis, antisense RINO1 cDNA was expressed under the control of the Ole18 promoter, directing the same spatial pattern in seeds as RINO1 in transgenic rice plants. The generated transgenic rice plants showed strong ,low phytic acid' (lpa) phenotypes, in which seed phytic acid was reduced by 68% and free available phosphate was concomitantly increased. No negative effects on seed weight, germination or plant growth were observed. The available phosphate levels of the stable transgenic plants surpassed those of currently available rice lpa mutants. [source] Functional analysis of rice NPR1 -like genes reveals that OsNPR1/NH1 is the rice orthologue conferring disease resistance with enhanced herbivore susceptibility,PLANT BIOTECHNOLOGY JOURNAL, Issue 2 2007Yuexing Yuan Summary The key regulator of salicylic acid (SA)-mediated resistance, NPR1, is functionally conserved in diverse plant species, including rice (Oryza sativa L.). Investigation in depth is needed to provide an understanding of NPR1 -mediated resistance and a practical strategy for the improvement of disease resistance in the model crop rice. The rice genome contains five NPR1 -like genes. In our study, three rice homologous genes, OsNPR1/NH1, OsNPR2/NH2 and OsNPR3, were found to be induced by rice bacterial blight Xanthomonas oryzae pv. oryzae and rice blast Magnaporthe grisea, and the defence molecules benzothiadiazole, methyl jasmonate and ethylene. We confirmed that OsNPR1 is the rice orthologue by complementing the Arabidopsis npr1 mutant. Over-expression of OsNPR1 conferred disease resistance to bacterial blight, but also enhanced herbivore susceptibility in transgenic plants. The OsNPR1-green fluorescent protein (GFP) fusion protein was localized in the cytoplasm and moved into the nucleus after redox change. Mutations in its conserved cysteine residues led to the constitutive localization of OsNPR1(2CA)-GFP in the nucleus and also abolished herbivore hypersensitivity in transgenic rice. Different subcellular localizations of OsNPR1 antagonistically regulated SA- and jasmonic acid (JA)-responsive genes, but not SA and JA levels, indicating that OsNPR1 might mediate antagonistic cross-talk between the SA- and JA-dependent pathways in rice. This study demonstrates that rice has evolved an SA-mediated systemic acquired resistance similar to that in Arabidopsis, and also provides a practical approach for the improvement of disease resistance without the penalty of decreased herbivore resistance in rice. [source] Quality variations in transgenic rice with a synthetic cry1Ab gene from Bacillus thuringiensisPLANT BREEDING, Issue 3 2002D. X. Wu Abstract In order to estimate the potential of transgenic rice, characteristics related to grain quality and starch viscosity were investigated in six japonica lines based on three primary transgenic lines containing a synthetic cry1Ab gene from Bacillus thuringiensis. No significant differences were found between the transgenic lines and the wild type, including negative lines and an untransformed line. All six transgenic lines were comparable in size, milling quality, appearance quality and physicochemical properties to the wild type that were derived from. One exception was that the lines derived from the primary transgenic line TR0-101 had smaller grains. Crude protein contents were equivalent in all the material tested, but Cry1Ab protein was only detected in grains of transgenic rice and was undetectable in the cooked rice. The viscosity of the starch differed between the transgenic lines, the wild type and other controls, and two transgenic lines had breakdown values (BDV) and setback values (SBV) similar to the wild type. A positional effect of T-DNA insertion on starch viscosity was found in three primary transgenic lines. [source] Mutations of genes in synthesis of the carotenoid precursors of ABA lead to pre-harvest sprouting and photo-oxidation in riceTHE PLANT JOURNAL, Issue 2 2008Jun Fang Summary Pre-harvest sprouting (PHS) or vivipary in cereals is an important agronomic trait that results in significant economic loss. A considerable number of mutations that cause PHS have been identified in several species. However, relatively few viviparous mutants in rice (Oryza sativa L.) have been reported. To explore the mechanism of PHS in rice, we carried out an extensive genetic screening and identified 12 PHS mutants (phs). Based on their phenotypes, these phs mutants were classified into three groups. Here we characterize in detail one of these groups, which contains mutations in genes encoding major enzymes of the carotenoid biosynthesis pathway, including phytoene desaturase (OsPDS), ,-carotene desaturase (OsZDS), carotenoid isomerase (OsCRTISO) and lycopene , -cyclase (,-OsLCY), which are essential for the biosynthesis of carotenoid precursors of ABA. As expected, the amount of ABA was reduced in all four phs mutants compared with that in the wild type. Chlorophyll fluorescence analysis revealed the occurrence of photoinhibition in the photosystem and decreased capacity for eliminating excess energy by thermal dissipation. The greatly increased activities of reactive oxygen species (ROS) scavenging enzymes, and reduced photosystem (PS) II core proteins CP43, CP47 and D1 in leaves of the Oscrtiso/phs3-1mutant and OsLCY RNAi transgenic rice indicated that photo-oxidative damage occurred in PS II, consistent with the accumulation of ROS in these plants. These results suggest that the impairment of carotenoid biosynthesis causes photo-oxidation and ABA-deficiency phenotypes, of which the latter is a major factor controlling the PHS trait in rice. [source] The redistribution of protein sulfur in transgenic rice expressing a gene for a foreign, sulfur-rich proteinTHE PLANT JOURNAL, Issue 1 2003N. D. Hagan Summary Sulfur amino acid composition is an important determinant of seed protein quality. A chimeric gene encoding sunflower seed albumin (SSA), one of the most sulfur-rich seed storage proteins identified so far, was introduced into rice (Oryza sativa) in order to modify cysteine and methionine content of the seed. Analysis of a transgenic line expressing SSA at approximately 7% of total seed protein revealed that the mature grain showed little change in the total sulfur amino acid content compared to the parental genotype. This result indicated that the transgenic rice grain was unable to respond to the added demand for cysteine and methionine imposed by the production of SSA. Analysis of the protein composition of the transgenic grain showed changes in the relative levels of the major seed storage proteins, as well as some non-storage proteins, compared to non-transgenic controls. Changes observed at the protein level were concomitant with differences in mRNA accumulation but not always with the level of transcription. The limited sulfur reserves appeared to be re-allocated from endogenous proteins to the new sulfur sink in the transgenic grain. We hypothesize that this response is mediated by a signal transduction pathway that normally modulates seed storage protein composition in response to environmental fluctuations in sulfur availability, via both transcriptional and post-transcriptional control of gene expression. [source] | ||||||||||