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Research Interests: Plant Biology, Biology, Medicine, Gene expression, Estrogen Receptor, and 15 moreRice, Polymerase Chain Reaction, Oryza Sativa, Plant Roots, Green Fluorescent Protein, Arabidopsis, Estrogens, Gene Function, Gramineae, GFP, Transgenic plant, Time Course, Oryza Sativa L, Genetically Modified Rice, and Expression pattern
Agrobacterium-mediated transformation of kabocha squash (Cucurbita moschata Duch) induced by wounding with aluminum borate whiskers
Ó The Author(s) 2010. This article is published with open access at Springerlink.com Abstract We investigated estrogen-inducible green fluorescent protein (GFP) expression patterns using an estrogen receptor fused chimeric transcription... more
Ó The Author(s) 2010. This article is published with open access at Springerlink.com Abstract We investigated estrogen-inducible green fluorescent protein (GFP) expression patterns using an estrogen receptor fused chimeric transcription activator, XVE, in the monocotyledonous model plant rice (Oryza sativa L.). This system has been shown to be an effective chemical-inducible gene expression system in Arabidopsis and has been applied to other plants in order to investigate gene functions or produce marker-free transgenic plants. However, limited information is available on the correlation between inducer concentration and the expression level of the gene induced in monocots. Here, we produced a transgenic rice integrated estrogen-inducible GFP expression vector, pLex:GFP, and investigated dose– response and time-course patterns of GFP induction in rice calli and seedlings for the first time. With 17-b-estradiol treatment at [5 lM, GFP signals were detected in the entire surface of ca...
The processing of chloroplast RNA requires a large number of nuclear-encoded RNA-binding proteins (RBPs) that are imported post-translationally into the organelle. The chloroplast ribonucleoprotein 31A (CP31A) supports RNA editing at 13... more
The processing of chloroplast RNA requires a large number of nuclear-encoded RNA-binding proteins (RBPs) that are imported post-translationally into the organelle. The chloroplast ribonucleoprotein 31A (CP31A) supports RNA editing at 13 sites and also supports the accumulation of multiple chloroplast mRNAs. In cp31a mutants it is the ndhF mRNA (coding for a subunit of the NDH complex) that is most strongly affected. CP31A becomes particularly important at low temperatures, where it is essential for chloroplast development in young tissue. Next to two RNA-recognition motifs (RRMs), CP31A has an N-terminal acidic domain that is phosphorylated at several sites. We investigated the function of the acidic domain in the role of CP31A in RNA metabolism and cold resistance. Using point mutagenesis, we demonstrate that the known phosphorylation sites within the acidic domain are irrelevant for any of the known functions of CP31A, both at normal and at low temperatures. Even when the entire a...
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Chloroplast RNA processing requires a large number of nuclear-encoded RNA binding proteins (RBPs) that are imported post-translationally into the organelle. Most of these RBPs are highly specific for one or few target RNAs. By contrast,... more
Chloroplast RNA processing requires a large number of nuclear-encoded RNA binding proteins (RBPs) that are imported post-translationally into the organelle. Most of these RBPs are highly specific for one or few target RNAs. By contrast, members of the chloroplast ribonucleoprotein family (cpRNPs) have a wider RNA target range. We here present a quantitative analysis of RNA targets of the cpRNP CP31A using digestion-optimized RNA co-immunoprecipitation with deep sequencing (DO-RIP-seq). This identifies the mRNAs coding for subunits of the chloroplast NAD(P)H dehydrogenase (NDH) complex as main targets for CP31A. We demonstrate using whole-genome gene expression analysis and targeted RNA gel blot hybridization that the ndh mRNAs are all down-regulated in cp31a mutants. This diminishes the activity of the NDH complex. Our findings demonstrate how a chloroplast RNA binding protein can combine functionally related RNAs into one post-transcriptional operon.
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Chloroplast gene expression is characterized by a multitude of post-transcriptional events as well as long-lived mRNAs. Given that the chloroplast is responsible for expressing core components of the photosynthetic apparatus, it is not... more
Chloroplast gene expression is characterized by a multitude of post-transcriptional events as well as long-lived mRNAs. Given that the chloroplast is responsible for expressing core components of the photosynthetic apparatus, it is not surprising that the accumulation and processing of chloroplast RNA is heavily affected by various external and internal cues, including light and temperature changes. A multitude of nuclear-encoded RNA-binding proteins (RBPs) are known to be required for chloroplast RNA metabolism, but we do not yet know how chloroplast RBPs convert abiotic signals into gene expression changes. Previous studies showed that chloroplast ribonucleoprotein 31A (CP31A) is required for the stabilization of multiple chloroplast mRNAs in the cold, and that the phosphorylation of CP31A at various residues within its N-terminal acidic domain (AD) can alter its affinity for RNA in vitro. Here, we demonstrate that CP31A shows increased affinity for a large number of chloroplast R...
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Chlorophyll degradation plays important roles in leaf senescence including regulation of degradation of chlorophyll-binding proteins. Although most genes encoding enzymes of the chlorophyll degradation pathway have been identified, the... more
Chlorophyll degradation plays important roles in leaf senescence including regulation of degradation of chlorophyll-binding proteins. Although most genes encoding enzymes of the chlorophyll degradation pathway have been identified, the regulation of their activity has not been fully understood. Green cotyledon mutants in legume are stay-green mutants, in which chlorophyll degradation is impaired during leaf senescence and seed maturation. Among them, the soybean (Glycine max) green cotyledon gene cytG is unique because it is maternally inherited. To isolate cytG, we extensively sequenced the soybean chloroplast genome, and detected a 5-bp insertion causing a frame-shift in psbM, which encodes one of the small subunits of photosystem II. Mutant tobacco plants (Nicotiana tabacum) with a disrupted psbM generated using a chloroplast transformation technique had green senescent leaves, confirming that cytG encodes PsbM. The phenotype of cytG was very similar to that of mutant of chloroph...
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Site-specific mutagenesis in a rice genome was obtained by introducing chimeric RNA/DNA oligonucleotides (COs) by means of particle bombardment. Three COs were designed to target the independent codons for Pro-171, Trp-548 and Ser-627 of... more
Site-specific mutagenesis in a rice genome was obtained by introducing chimeric RNA/DNA oligonucleotides (COs) by means of particle bombardment. Three COs were designed to target the independent codons for Pro-171, Trp-548 and Ser-627 of the endogenous rice acetolactate synthase (ALS) gene so it would confer resistance to ALS-inhibiting herbicides. Sequencing of the ALS gene of herbicide-resistant plants demonstrated that the ALS sequence was modified in a site-specific fashion. The efficiency of gene conversion mediated by COs was estimated to be 1x10(-4). These results demonstrate that CO-directed gene targeting is feasible in rice.