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Transgenic Rice Plants (transgenic + rice_plant)
Selected AbstractsA rice promoter containing both novel positive and negative cis -elements for regulation of green tissue-specific gene expression in transgenic plantsPLANT BIOTECHNOLOGY JOURNAL, Issue 5 2007Meng Cai Summary The tissue-specific expression of transgenes is essential in plant breeding programmes to avoid the fitness costs caused by constitutive expression of a target gene. However, knowledge on the molecular mechanisms of tissue-specific gene expression and practicable tissue-specific promoters is limited. In this study, we identified the cis -acting elements of a tissue-specific promoter from rice, PD54O, and tested the application of original and modified PD54O and its cis -elements in the regulation of gene expression. PD54O is a green tissue-specific promoter. Five novel tissue-specific cis -elements (LPSE1, LPSE2, LPSRE1, LPSRE2, PSE1) were characterized from PD54O. LPSE1 activated gene expression in leaf and young panicle. LPSRE2 suppressed gene expression in leaf, root, young panicle and stem, and PSE1 suppressed gene expression in young panicle and stem. LPSRE1 and LPSE2 had dual roles in the regulation of tissue-specific gene expression; both functioned as activators in leaf, but LPSRE1 acted as a repressor in stem and LPSE2 as a repressor in young panicle and root. Transgenic rice plants carrying cry1Ac encoding Bacillus thuringiensis endotoxin, regulated by PD54O, were resistant to leaf-folders, with no Cry1Ac protein found in endosperm or embryo. A reporter gene regulated by a series of truncated PD54O showed various tissue-specific expression patterns. Different fragments of PD54O fused with the constitutive cauliflower mosaic virus 35S promoter suppressed 35S -regulated gene expression in various tissues. PD54O, truncated PD54O and the tissue-specific cis -elements provide useful tools for the regulation of tissue-specific gene expression in rice breeding programmes. [source] Overexpression of rice isoflavone reductase-like gene (OsIRL) confers tolerance to reactive oxygen speciesPHYSIOLOGIA PLANTARUM, Issue 1 2010Sang Gon Kim Isoflavone reductase is an enzyme involved in isoflavonoid biosynthesis in plants. However, rice isoflavone reductase-like gene (OsIRL, accession no. AY071920) has not been unraveled so far. Here, we have characterized its behavior in response to oxidizing agents. Using Northern and Western blot analyses, the OsIRL gene and protein were shown to be down-regulated in young seedling roots treated with reduced glutathione (GSH) and diphenyleneiodonium (DPI), known quenchers of reactive oxygen species (ROS). The OsIRL transcript level in rice suspension-cultured cells was also found to be induced by oxidants such as hydrogen peroxide (H2O2), ferric chloride (FeCl3), methyl viologen (MV) and glucose/glucose oxidase (G/GO), but down-regulated when co-treated with GSH. Furthermore, to investigate whether overexpression of OsIRL in transgenic rice plants promotes resistance to ROS, we generated transgenic rice lines overexpressing the OsIRL gene under an abscisic acid (ABA) inducible promoter. Results showed that the OsIRL transgenic rice line activated by ABA treatment was tolerant against MV and G/GO-induced stress in rice leave and suspension-cultured cells. Our results strongly suggest the involvement of OsIRL in homeostasis of ROS. [source] The SUI-homologous translation initiation factor eIF-1 is involved in regulation of ion homeostasis in ricePLANT BIOLOGY, Issue 3 2008C. J. Diédhiou Abstract Halophytes survive high salinity by using complex adaptive mechanisms. In a search for novel molecular mechanisms involved in salt acclimation, transcript analyses revealed increased expression of a SUI-homologous translation initiation factor eIF-1 in the salt-tolerant grass species Festuca rubra ssp. littoralis but not in rice. Upon analysis of the cell specificity of eIF-1 transcription by in situ polymerase chain reaction (PCR), predominant signals were detected in rice leaf mesophyll. To further examine the role of eIF-1 in salt tolerance, transgenic rice plants were generated that over-express this factor under the control of the CaMV-35S promoter. The eIF-1 over-expressing lines showed improved growth under salt stress that was correlated with maintenance of photosynthetic activity and reduced Na+ and Cl, accumulation in leaves. The transgenic rice lines also activated expression of the vacuolar H+ -ATPase. In addition, an oxidoreductase that belongs to the aldo/keto reductase family was identified as a gene with modified expression in the eIF-1 over-expressing lines, compared with wild-type rice. Our data suggest that eIF-1 has a central function in salt-stress adaptation in rice by regulating ion accumulation and the intracellular redox status. [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] Dual targeting of Myxococcus xanthus protoporphyrinogen oxidase into chloroplasts and mitochondria and high level oxyfluorfen resistancePLANT CELL & ENVIRONMENT, Issue 11 2004S. JUNG ABSTRACT Much attention has been paid to the signal sequences of eukaryotic protoporphyrinogen oxidases (protoxes); both the organelles targeted by protoxes and the role of protoxes in conferring resistance against protox-inhibiting herbicides, such as oxyfluorfen, have been examined. However, there have been no reports on the translocation of prokaryotic protoxes. This study investigated the targeting ability of Myxococcus xanthus protox in vitro and in vivo. In an in vitro translocation assay using a dual import system, M. xanthus protein was detected in chloroplasts and mitochondria, suggesting that the M. xanthus protox protein was targeted into both organelles. In order to confirm the in vitro dual targeting ability of M. xanthus, we used a stable transgenic strategy to investigate dual targeting in vivo. In transgenic rice plants overexpressing M. xanthus protox, M. xanthus protox antibody cross-reacted with proteins with predicted molecular masses of 50 kDa from both chloroplasts and mitochondria, and this in vivo transgene expression corresponded to a prominent increase in chloroplastic and mitochondrial protox activity. Seeds from the transgenic lines M4 and M7 germinated in solid Murashige and Skoog media of up to 500 µm of oxyfluorfen, whereas wild-type seeds did not germinate in 1 µm. After 4-week-old-rice plants were treated with oxyfluorfen for 3 d, lines M4 and M7 exhibited normal growth, whereas the wild-type line was severely bleached and necrotized. The herbicidal resistance is attributed to the insignificant accumulation of photodynamic protoporphyrin IX in cytosol because the high chloroplastic and mitochondrial protox activity in oxyfluorfen-treated transgenic lines, compared with that in oxyfluorfen-treated and untreated wild-type plants, metabolizes protoporphyrinogen IX to chlorophyll and heme. A practical application of the dual targeting of M. xanthus protox for obtaining outstanding resistance to peroxidizing herbicides is discussed. [source] Protein,protein interactions of tandem affinity purification-tagged protein kinases in riceTHE PLANT JOURNAL, Issue 1 2006Jai S. Rohila Summary Forty-one rice cDNAs encoding protein kinases were fused to the tandem affinity purification (TAP) tag and expressed in transgenic rice plants. The TAP-tagged kinases and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by mass spectrometry. Ninety-five percent of the TAP-tagged kinases were recovered. Fifty-six percent of the TAP-tagged kinases were found to interact with other rice proteins. A number of these interactions were consistent with known protein complexes found in other species, validating the TAP-tag method in rice plants. Phosphorylation sites were identified on four of the kinases that interacted with either 14-3-3 proteins or cyclins. [source] |