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characterization of an inducible p450 hydroxylase involved in the rice diterpene phytoalexin biosynthetic pathway.ent-isopimara-8(14),15-dien-3 beta-ol (1) was isolated from uv-irradiated rice (oryza sativa l.) leaves. since 1 was converted to the rice diterpene phytoalexins and oryzalexins d (ent-isopimara-8(14),15-diene-3 beta,7 alpha-diol) and e (ent-isopimara-8(14),15-diene-3 beta,9 alpha-diol) in uv-irradiated rice leaf microsome fraction in the presence of oxygen and nadph, it was concluded that 1 was the biosynthetic precursor of these oryzalexins. this enzyme reaction was inhibited by cytochrome p45 ...19957864625
patterns of light and nitrogen distribution in relation to whole canopy carbon gain in c3 and c4 mono- and dicotyledonous species.an analytical model was used to describe the optimal nitrogen distribution. from this model, it was hypothesized that the non-uniformity of the nitrogen distribution increases with the canopy extinction rate for light and the total amount of free nitrogen in the canopy, and that it is independent of the slope of the relation between light saturated photosynthesis (pm) and leaf nitrogen content (nl). these hypotheses were tested experimentally for plants with inherently different architectures an ...199528306967
genetic diversity and phylogeny analysis of anabaena azollae based on rflps detected in azolla-anabaena azollae dna complexes using nif gene probes.the cyanobacterium anabaena has both symbiotic and free-living forms. the genetic diversity of anabaena strains symbiotically associated with the aquatic fern azolla and the evolutionary relationships among these symbionts were evaluated by means of rflp (restriction fragment length polymorphism) experiments. three dna fragments corresponding to nif genes were cloned from the free-living cyanobacterium anabaena pcc 7120 and used as probes. a mixture of azolla, anabaena and bacterial dna was extr ...199524169885
[the goal-oriented project "pathology of environmental pollutants" (m.u.r.s.t. 40%)].the purpose of this study was to estimate to toxicity bound to effluent water, pore water and bed sediment sampled twice during 1994 (spring and autumn) from 16 tributaries of po river. toxicity was determined by using a battery of bioassays (artemia salina, dugesiagonocephala and thamnocephalus platyurus) and a battery of phytoassays, including oryza sativa and triticum sativum. results show that practically no toxicity is found in effluent water, mild adverse effects are obtained with sediment ...19958991825
cloning and characterization of a cdna encoding an 18.0-kda class-i low-molecular-weight heat-shock protein from rice.a novel cdna clone, oshp18.0 cdna, encoding a rice (oryza sativa l. cv. tainong 67) 18.0-kda heat-shock protein (hsp), was isolated from a cdna library of heat-shocked rice seedlings by use of the rice hsp cdna, oshsp17.3 cdna, as a probe. the sequence showed that oshsp18.0 cdna contains a 749-bp insert encoding an orf of 160 amino acids, with a predicted molecular mass of 18.0 kda and a pi of 7.3. sequence comparison reveals that oshsp18.0 cdna is highly homologous to other low-molecular-weight ...19958522180
cloning and properties of a rice gene encoding phenylalanine ammonia-lyase.phenylalanine ammonia-lyase (pal) genomic sequences were isolated from a rice (oryza sativa l.) genomic library using a pcr-amplified rice pal dna fragment as a probe. there is a small family of pal genes in the rice genome. the nucleotide sequence of one pal gene, zb8, was determined. the zb8 gene is 4660 bp in length and consists of two exons and one intron. it encodes a polypeptide of 710 amino acids. the transcription start site was 137 bp upstream from the translation initiation site. rice ...19958534851
nramp defines a family of membrane proteins.nramp (natural resistance-associated macrophage protein) is a newly identified family of integral membrane proteins whose biochemical function is unknown. we report on the identification of nramp homologs from the fly drosophila melanogaster, the plant oryza sativa, and the yeast saccharomyces cerevisiae. optimal alignment of protein sequences required insertion of very few gaps and revealed remarkable sequence identity of 28% (yeast), 40% (plant), and 55% (fly) with the mammalian proteins (46%, ...19957479731
a comparative study of cadmium, lead, zinc, ph, and bulk density from the enyigba lead and zinc mine in two different seasons.soil ph and bulk density, as well as the concentrations of cadmium (cd), lead (pb), and zinc (zn) in soils and these metal levels in the leaves of cassava (manihot esculenta) and rice (oryza sativa), both collected, respectively, in the dry season (december) of 1991 and the rainy season (september) of 1992 from the enyigba lead and zinc mine, nigeria, were investigated. interspecific variations in trace element levels in the plant leaves were detected and may reflect the predilection of these pl ...19957498063
rice scutellum induces agrobacterium tumefaciens vir genes and t-strand generation.for successful transformation of a plant by agrobacterium tumefaciens it is essential that the explant used in cocultivation has the ability to induce agrobacterium tumour-inducing (ti) plasmid virulence (vir) genes. here we report a significant variation in different tissues of indica rice (oryza sativa l. cv. co43) in their ability to induce agrobacterium tumefaciens vir genes and t-strand generation, using explants preincubated in liquid murashige and skoog (ms) medium. an analysis of rice le ...19957579158
an amino-terminal deletion of rice phytochrome a results in a dominant negative suppression of tobacco phytochrome a activity in transgenic tobacco seedlings.overexpression of phytochrome a results in an increased inhibition of hypocotyl elongation under red and far-red light. we used this approach to assay for the function of n-terminal mutations of rice (oryza sativa l.) phytochrome a. transgenic tobacco seedlings that express the wild-type rice phytochrome a (rw), a rice phytochrome a lacking the first 80 amino acids (ntd) or a rice phytochrome a with a conversion of the first 10 serines into alanine residues (s/a) were compared with untransformed ...19957580859
2,3-bisphosphoglycerate-independent phosphoglycerate mutase is conserved among different phylogenic kingdoms.we have previously demonstrated that maize (zea mays) 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (pgam-i) is not related to 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase. with the aid of specific anti-maize pgam-i antibodies, we demonstrate here the presence of a closely related pgam-i in other plants. we also describe the isolation and sequencing of a cdna-encoding almond (prunus amygdalus) pgam-i that further demonstrates this relationship among plant pgam-i. a sea ...19957584858
the regulatory regions of the rice tungro bacilliform virus promoter and interacting nuclear factors in rice (oryza sativa l.).the rice tungro bacilliform virus (rtbv) promoter confers phloem-specific gene expression in transgenic rice plants. a series of promoter deletion mutants were fused with the escherichia coli beta-glucuronidase a (uida) reporter gene and introduced into transgenic rice plants. the rtbv promoter confers substantially stronger expression in shoots than in roots. a fragment of the promoter comprising nucleotides -164 to +45 relative to the transcriptional start site contains sufficient information ...19957599653
fractionation and characterization of two forms of peroxidase from oryza sativa.peroxidase (e.c. 1.11.1.7., hydrogen donor oxidoreductase) is widely distributed and has been isolated from many higher plants (1). the wide distribution of the enzyme suggests that it could be of great biological importance. however the role that it plays in metabolism is not clear due to the large number of reactions it catalyzes and the considerable number of isozymic species (2). in tomato plants, evans and aldridge (3) separated out six isoperoxidases and in a later paper evans reported 12 ...19957603969
proline accumulates in plants exposed to uv radiation and protects them against uv induced peroxidation.proline accumulated in the shoots of seedlings of rice (oryza sativa), mustard (brassica juncea) and mung bean (vigna radiata) exposed to uv radiations. the level of proline in the seedlings increased significantly with increase in uv exposure time. the production of malondialdehyde (an indice of lipid peroxidation) was also higher in the shoots of seedlings exposed to uv radiation as compared to controls, suggesting that uv radiations promote lipid peroxidation. the extent of uv radiation promo ...19957726821
the atx1 gene of saccharomyces cerevisiae encodes a small metal homeostasis factor that protects cells against reactive oxygen toxicity.in aerobic organisms, protection against oxidative damage involves the combined action of highly specialized antioxidant enzymes, such as superoxide dismutase (sod) and catalase. here we describe the isolation and characterization of another gene in the yeast saccharomyces cerevisiae that plays a critical role in detoxification of reactive oxygen species. this gene, named atx1, was originally isolated by its ability to suppress oxygen toxicity in yeast lacking sod. atx1 encodes a 8.2-kda polypep ...19957731983
metaphase and interphase fluorescence in situ hybridization mapping of the rice genome with bacterial artificial chromosomes.fluorescence in situ hybridization (fish) is a powerful tool for physical mapping in human and other mammalian species. however, application of the fish technique has been limited in plant species, especially for mapping single- or low-copy dna sequences, due to inconsistent signal production in plant chromosome preparations. here we demonstrate that bacterial artificial chromosome (bac) clones can be mapped readily on rice (oryza sativa l.) chromosomes by fish. repetitive dna sequences in bac c ...19957753830
thioredoxin h is one of the major proteins in rice phloem sap.sieve tubes play important roles in the transfer of nutrients as well as signals. hundreds of proteins were found in pure phloem sap collected from rice (oryza sativa l. cv. kantou) plants through the cut ends of insect stylets. these proteins may be involved in nutrient transfer and signal transduction. to characterize the nature of these proteins, the partial amino-acid sequence of a 13-kda protein, named rpp13-1, that was abundant in the pure phleom sap was determined. a cdna clone of 687 bp, ...19957766047
expression of functional proteins of cdna encoding rice nucleoside diphosphate kinase (ndk) in escherichia coli and organ-related alteration of ndk activities during rice seed germination (oryza sativa l.).the gst (glutathione s-transferase)-ndk (nucleoside diphosphate kinase) fusion protein was expressed in escherichia coli. the gst-ndk protein was capable of transferring gamma-phosphate from atp to nucleoside diphosphates such as gdp, cdp, tdp and udp. western blot analysis using anti-ndk antibody indicated that ndk in endosperm gradually decreased during 36 h of imbibition. on the contrary, ndk in embryo increased during the same period. ndk activities in both tissues were in accord with these ...19957766875
biochemical properties of rice adenylate kinase and subcellular location in plant cells.previously, we characterized nucleotide sequences of two cdnas encoding adenylate kinase from rice plants (oryza sativa l.). each cdna (adk-a or adk-b) was cloned into the expression vector pet 11d-gst to produce gst-ak fusion proteins in escherichia coli. recombinant proteins were cleaved by thrombin, and gst-free adenylate kinase proteins were obtained. enzyme activity profiles of different ph and inhibition effects to the enzyme by ap5a (adenosine-5'-pentaphospho-5'-adenosine) indicates that ...19957766884
molecular cloning and characterization of rga1 encoding a g protein alpha subunit from rice (oryza sativa l. ir-36).a cdna clone, rga1, was isolated by using a gpa1 cdna clone of arabidopsis thaliana g protein alpha subunit as a probe from a rice (oryza sativa l. ir-36) seedling cdna library from roots and leaves. sequence analysis of genomic clone reveals that the rga1 gene has 14 exons and 13 introns, and encodes a polypeptide of 380 amino acid residues with a calculated molecular weight of 44.5 kda. the encoded protein exhibits a considerable degree of amino acid sequence similarity to all the other known ...19957766894
rice cationic peroxidase accumulates in xylem vessels during incompatible interactions with xanthomonas oryzae pv oryzae.a cationic peroxidase, po-c1 (molecular mass 42 kd, isoelectric point 8.6), which is induced in incompatible interactions between the vascular pathogen xanthomonas oryzae pv oryzae and rice (oryza sativa l.), was purified. amino acid sequences from chemically cleaved fragments of po-c1 exhibited a high percentage of identity with deduced sequences of peroxidases from rice, barley, and wheat. polyclonal antibodies were raised to an 11-amino acid oligopeptide (poc1a) that was derived from a domain ...19957770527
the human archain gene, arcn1, has highly conserved homologs in rice and drosophila.a novel human gene, arcn1, has been identified in chromosome band 11q23.3. it maps approximately 50 kb telomeric to mll, a gene that is disrupted in a number of leukemia-associated translocation chromosomes. cdna clones representing arcn1 hybridize to 4-kb mrna species present in all tissues tested. sequencing of cdnas suggests that at least two forms of mrna with alternative 5' ends are present within the cell. the mrna with the longest open reading frame gives rise to a protein of 57 kda. alth ...19957782067
improvement in hc1-extractability of minerals in home made weaning foods.three weaning foods were formulated from locally available cereals and pulses such as rice (oryza sativa), kangini (setaria italica), sanwak (echinochloa frumentacea), green gram (vigna radiata) and jaggery. cereals and pulses were mixed in the proportion of 7:3. nutrient composition of developed weaning foods was within range prescribed by indian standard institute and was found to be acceptable. roasting was the processing technique employed in developing weaning foods which resulted in signif ...19957792266
structure and differential response to abscisic acid of two promoters for the cytosolic copper/zinc-superoxide dismutase genes, sodcc1 and sodcc2, in rice protoplasts.we determined the 5'-flanking sequences of two nuclear genes (sodcc1 and sodcc2) encoding cytosolic copper/zinc-superoxide dismutase in rice (oryza sativa l.). utilizing transient beta-glucuronidase (gus) reporter assays, functional promoter-gus analysis was performed in rice protoplasts exposed to the phytohormone abscisic acid (aba) or the antioxidant sulfhydryl reagent, dithiothreitol (dtt). transcriptional activities from both sodcc-gus fusions were stimulated by dtt, which induces the promo ...19957821431
synthesis of an infectious full-length cdna clone of rice yellow mottle virus and mutagenesis of the coat protein.a full-length cdna clone of rice yellow mottle sobemovirus (rymv) was synthesized and placed adjacent to a bacteriophage t7 rna polymerase promoter sequence. capped-rna transcripts produced in vitro were infectious when mechanically inoculated onto rice plants (oryza sativa l). individual full-length clones varied in their degree of infectivity but all were less infectious than native viral rna. a representative clone, designated rymv-fl5, caused a disease phenotype identical to that produced by ...19957831766
inheritance of gusa and neo genes in transgenic rice.inheritance of foreign genes neo and gusa in rice (oryza sativa l. cv. ir54 and radon) has been investigated in three different primary (t0) transformants and their progeny plants. t0 plants were obtained by co-transforming protoplasts from two different rice suspension cultures with the neomycin phosphotransferase ii gene [neo or aph (3') ii] and the beta-glucuronidase gene (uida or gusa) residing on separate chimeric plasmid constructs. the suspension cultures were derived from callus of immat ...19957865799
novel drosophila melanogaster genes encoding rrm-type rna-binding proteins identified by a degenerate pcr strategy.we are interested in identifying drosophila melanogaster rna-binding proteins involved in important developmental decisions made at the level of mrna processing, stability, localization or translational control. a large subset of the proteins known to interact with specific rna sequences shares an evolutionarily conserved 80-90-amino-acid (aa) domain referred to as an rna-recognition motif (rrm), including two ribonucleoprotein identifier sequences known as rnp-1 and rnp-2. hence, we have herein ...19957890163
salicylic acid in rice (biosynthesis, conjugation, and possible role).salicylic acid (sa) is a natural inducer of disease resistance in some dicotyledonous plants. rice seedlings (oryza sativa l.) had the highest levels of sa among all plants tested for sa content (between 0.01 and 37.19 [mu]g/g fresh weight). the second leaf of rice seedlings had slightly lower sa levels than any younger leaves. to investigate the role of sa in rice disease resistance, we examined the levels of sa in rice (cv m-201) after inoculation with bacterial and fungal pathogens. sa levels ...199512228500
characterization and physiological function of class i low-molecular-mass, heat-shock protein complex in soybean.examination of an ammonium sulfate-enriched fraction (70-100% saturation) of heat-shock proteins (hsps) by nondenaturing polyacrylamide gel electrophoresis revealed the presence of a high molecular mass complex (280 kd) in soybean (glycine max) seedlings. this complex cross-reacted with antibodies raised against soybean class i low-molecular-mass (lmw) hsps. dissociation of the complex by denaturing polyacrylamide gel electrophoresis showed the complex to contain at least 15 polypeptides of the ...199512228501
rflp analysis of the progeny from oryza alta swallen x oryza sativa l.rflp analyses were carried out in the progeny from a cross of two phylogenetically distant rice species, wild rice oryza alta swallen (ccdd, 2n = 48) and cultivated rice o. sativa l. (aa, 2n = 24). the sterile plants gave heterozygous rflp patterns at most of the loci detected. they looked more like their wild rice parent, with 36 chromosomes in their root-tip cells and pollen mother cells. in two partially fertile plants, however, most of the markers that were used showed rflp patterns similar ...199518470217
morphometric analysis of rice seed protein bodies (implication for a significant contribution of prolamine to the total protein content of rice endosperm).electron microscopic observation of thin sections of rice (oryza sativa l.) endosperm revealed two types of protein bodies (pbs): spherical and irregular-shaped ones. immunocytochemical localization studies using antibodies raised against purified glutelins, prolamines, and globulins indicated that the prolamines were localized in the spherical pb, whereas the irregular-shaped pb contained glutelins and globulins. we counted and measured the surface area and the relative volume of 2303 pbs rando ...199512228685
mitochondrial plasmid-like dnas of the b1 family in the genus oryza: sequence heterogeneity and evolution.four kinds of circular plasmid-like dna, designated b1, b2, b3 and b4, have been found in the mitochondria of oryza sativa l. with an aa genome. three novel b1-homologous mitochondrial plasmid-like dnas, designated, m1, m2 and m3, were isolated in the present study from strains with cc and ccdd genomes in the genus oryza. we cloned and sequenced these dnas and found that the sequences of these molecules have wide regions of homology. b1, m2 and m3 each lack about 300 bp of a region that is prese ...19958790446
genomic organization of 57 ribosomal protein genes in rice (oryza sativa l.) through rflp mapping.four hundred cdna clones from rice (oryza sativa l.) callus and root cdna libraries, with a high similarity to about 70 kinds of ribosomal proteins (r-protein) in eukaryotic as well as procaryotic organisms, were identified by their deduced amino acid sequences. southern hybridization of 114 independent cdna clones with total rice genomic dna showed 77 distinct and specific hybridization patterns. of the 77 clones representing the above hybridization patterns, copies of 67 clones corresponding t ...19958654915
frequency of microsatellite sequences in rice (oryza sativa l.).this study was undertaken to estimate the relative frequencies of 13 microsatellite motifs in the rice genome as a basis for efficient development of a microsatellite map. two dinucleotide, seven trinucleotide, and four tetranucleotide repeat motifs were end labelled and used as hybridization probes to screen genomic and cdna libraries of rice, cv. ir36. optimal washing temperatures for identification of clones containing specific microsatellite motifs were estimated based on washing temperature ...19958654913
inhibition of gibberellin-induced elongation growth of rice by feruloyl oligosaccharides.the biological activity of cell wall-derived feruloyl oligosaccharides was investigated using a modified micro-drop bioassay. a feruloyl arabinoxylan trisaccharide (faxx) and a feruloyl arabinoxylan tetrasaccharide (faxxx) were found to inhibit the gibberellin-induced elongation of dwarf rice (oryza sativa l., cv, tan-ginbozu) that had been treated with uniconazole (s-3307), an inhibitor of the biosynthesis of gibberellins. an arabinoxylan trisaccharide (axx) was ineffective. the growth-inhibito ...19958589928
an integration of photosynthetic traits and mechanisms that can increase crop photosynthesis and grain production.the hypothesis we propose is that during photosynthesis the balance between potentially detrimental and beneficial photochemically induced events can be tipped beneficially toward increased photosynthesis and toward increased crop yield. to test this hypothesis a procedure has been devised with the rice plant, oryza sativa, that has resulted in increasing both canopy photosynthesis and rice grain yield. two elite rice varieties selected independently in the contrasting environments of either sou ...199524301579
tagging and mapping the thermo-sensitive genic male-sterile gene in rice (oryza sativa l.) with molecular markers.the thermo-sensititve genic male-sterile (tgms) gene in rice can alter fertility in response to temperature and is useful in the two-line system of hybrid rice production. however, little is known about the tgms gene at the molecular level. the objective of this study was to identify molecular markers tightly linked with the tgms gene and to map the gene onto a specific rice chromosome. bulked segregant analysis of an f2 population from 5460s (a tgms mutant line) x 'hong wan 52' was used to iden ...199524170005
the bean seed storage protein [beta]-phaseolin is synthesized, processed, and accumulated in the vacuolar type-ii protein bodies of transgenic rice endosperm.the seed storage protein [beta]-phaseolin of the common bean (phaseolus vulgaris l.) was expressed in the endosperm of transgenic rice (oryza sativa l.) plants. the 5.1- or 1.8-kb promoter fragment of the rice seed storage protein glutelin gt1 gene was fused transcriptionally to either the genomic or cdna coding sequence of the [beta]-phaseolin gene. the highest quantity of phaseolin estimated by enzyme-linked immunosorbent assay was 4.0% of the total endosperm protein in the transgenic rice see ...199512228632
expression of functional oat phytochrome a in transgenic rice.to investigate the biological functions of phytochromes in monocots, we generated, by electric discharge particle bombardment, transgenic rice (oryza sativa cv gulfmont) that constitutively expresses the oat phytochrome a apoprotein. the introduced 124-kd polypeptide bound chromophore and assembled into a red- and far-red-light-photoreversible chromoprotein with absorbance spectra indistinguishable from those of phytochrome purified from etiolated oats. transgenic lines expressed up to 3 and 4 t ...19958552709
cloning and nucleotide sequence of a leaf ferredoxin-nitrite reductase cdna of rice.a ferredoxin-nitrite reductase (ec 1.7.7.1) cdna was isolated and sequenced from a lambda gt 11 cdna library constructed from nitrate-induced greening shoots of rice (oryza sativa l.) seedlings. the nucleotide sequence of the cdna clone contains an open reading frame of 1788 nucleotides. there exists a strong bias for the third codon usage of g/c (95.5%) as in the case of the maize enzyme. the deduced amino acid sequence shows an overall homology to the maize (81%) and the dicot enzymes (70-74%) ...19958541663
a gibberellin-stimulated ubiquitin-conjugating enzyme gene is involved in alpha-amylase gene expression in rice aleurone.a ubiquitin-conjugating enzyme (ubc) gene, induced by gibberellin (ga) within an hour, was identified in rice (oryza sativa) seeds by the mrna differential display technique. ga inducibility was confirmed by rna hybridization. a full-length ubc cdna clone and a genomic clone have been isolated and sequenced. the deduced amino acid sequence shares a significant identity with several known ubc sequences, which are probably involved in the pathway responsible for degrading short-lived regulatory pr ...19958541504
analysis of randomly isolated cdnas from developing endosperm of rice (oryza sativa l.): evaluation of expressed sequence tags, and expression levels of mrnas.using a cdna library prepared from poly(a)+ rna from 10-day-old rice endosperm, partial nucleotide sequences of randomly isolated clones were analyzed. a total of 153 (30.6%) out of 500 cdna clones showed high amino acid identity to previously identified genes. there was significant redundancy in cdnas encoding prolamine and glutelin. about 21.0% of the cdna clones were found to code for seed storage protein genes. consequently, 37 independent genes were identified. using cdna clones encoding gl ...19958541495
neighboring base composition and transversion/transition bias in a comparison of rice and maize chloroplast noncoding regions.the correspondence between the transversion/transition ratio and the neighboring base composition in chloroplast dna is examined. for 18 noncoding regions of the chloroplast genome, alignments between rice (oryza sativa) and maize (zea mays) were generated by two different methods. difficulties of aligning noncoding dna are discussed, and the alignments are analyzed in a manner that reduces alignment artifacts. sequence divergence is < 10%, so multiple substitutions at a site are assumed to be r ...19957568204
a rapid method to monitor dna precipitation onto microcarriers before particle bombardment.the binding or precipitation of dna onto gold or tungsten microcarriers represents one of the most crucial steps for gene transfer via the particle bombardment process. we have developed a simple and rapid method to monitor dna precipitation onto microcarriers before delivery to intact cells or tissues. binding of dna constructs to different microcarriers was evaluated with relative fluorescence values using a dedicated fluorometer. significantly greater precipitation was detected using gold vs. ...199524186715
polymorphic distribution and molecular diversification of mitochondrial plasmid-like dnas in the genus oryza.four kinds of circular plasmid-like dna, designated b1, b2, b3 and b4, have been found in the mitochondria of rice (oryza sativa l.). we analyzed the distribution of families of plasmid-like dnas homologous to those of o. sativa in 40 strains of the genus oryza with aa, bb, bbcc, cc, ccdd and ee genomes. plasmid-like dnas were observed only strains having aa, cc and ccdd genomes. the distribution patterns of strains with aa genome were highly polymorphic. we amplified the plasmid-like dnas from ...19958527166
identification and gene expression of anaerobically induced enolase in echinochloa phyllopogon and echinochloa crus-pavonis.enolase (2-phospho-d-glycerate hydrolase, ec 4.2.1.11) has been identified as an anaerobic stress protein in echinochloa oryzoides based on the homology of its internal amino acid sequence with those of enolases from other organisms, by immunological reactivity, and induction of catalytic activity during anaerobic stress. enolase activity was induced 5-fold in anoxically treated seedlings of three flood-tolerant species (e. oryzoides, echinochloa phyllopogon, and rice [oryza sativa l.]) but not ...19957480340
complete sequence of the maize chloroplast genome: gene content, hotspots of divergence and fine tuning of genetic information by transcript editing.the nucleotide sequence of the chloroplast (cp) dna from maize (zea mays) has been completed. the circular double-stranded dna, which consists of 140,387 base-pairs, contains a pair of inverted repeat regions (ira and irb) with 22,748 base-pairs each, which are separated by a small and a large single copy region (ssc and lsc) of 12,536 and 82,355 base-pairs, respectively. the gene content and the relative positions of a total of 104 genes (70 peptide-encoding genes, 30 trna genes and four rrna g ...19957666415
plant regeneration from rice (oryza sativa l.) embryogenic suspension cells cryopreserved by vitrification.rice cells were precultured for 10 d in medium containing 60 g/l sucrose and subsequently for 1 d in medium supplemented with 0. 4 m sorbitol. after loading with 25%pvs2 at 22°c for 10 min and dehydration in 100%pvs2 at 0°c for 7. 5 min,they were plunged into liquid nitrogen directly. survival was 45. 0 ±5.1% (based on the reduction of triphenyl tetrazolium chloride)following warming and unloading. for regrowth, cells were plated on semi-solid medium replenished with 40%(w/v) starch for 2d prior ...199524186632
efficient plant regeneration from long-term callus cultures of rice by spermidine.a significant reduction in regeneration potential with increasing age (upto 12months) in rice (oryza sativa l. cv.tn-1) embryogenic callus cultures was observed. spermidine, while having an inhibitory effect on plant regeneration in fresh callus cultures, promoted morphogenesis in long-term callus cultures. a massive accumulation of polyamines, particularly putrescine (5-fold) was observed in 12 month old cultures resulting in a change of putrescine /spermidine ratio, which seems to be important ...199524186629
genetic variation detected by dna fingerprinting with a rice minisatellite probe in oryza sativa l.a rice minisatellite probe detecting dna fingerprints was used to assess genetic variation in cultivated rice (oryza sativa l.). fifty-seven cultivars of rice, including 40 closely related cultivars released in the us, were studied. rice dna fingerprinting revealed high levels of polymorphism among distantly related cultivars. the variability of fingerprinting pattern was reduced in the closely related cultivars. a genetic similarity index (s) was computed based on shared fragments between each ...199524169839
aneuhaploids and tetrasomics in rice (oryza sativa l.) derived from anther culture of trisomics.eight types of aneuhaploids (aneuhaplo 4, 5, 6, 8, 9, 10, 11, and 12) and eight types of tetrasomics (tetraplo 4, 5, 6, 7, 8, 9, 10, and 12) of rice have been obtained from anther culture of trisomics. this paper reports the plant morphology of these aneuploids and their chromosome behavior at metaphase i. aneuhaploids for different chromosomes are distinguishable from each other and are morphologically similar to the parental trisomics, suggesting that the extra chromosome has similar genetic e ...199518470197
diurnal regulation of leaf blade elongation in rice by co2 (is it related to sucrose-phosphate synthase activity?).the relationship between leaf blade elongation rates (ler) and sucrose-phosphate synthase (sps) activity was investigated at different times during ontogeny of rice (oryza sativa l. cv jarrah) grown in flooded soil at either 350 or 700 [mu]l co2 l-1. high co2 concentrations increased ler of expanding blades and in vivo activity (vlimiting) sps activity of expanded blades during the early vegetative stage (21 d after planting [dap]), when tiller number was small and growing blades were strong car ...199512228556
current developments in plant biotechnology for genetic improvement: the case of rice (oryza sativa l.).as the world's population is expanding rapidly, all possible techniques for crop improvement must be utilized to meet the food demands of the next century. although conventional breeding techniques have considerably increased the productivity of modern crops, the application of advanced molecular technologies could speed up further crop improvement. use of biotechnology, such as the various tissue-culture methods and gene-transfer techniques now available, could significantly shorten the breedin ...199524414747
identification of quantitative trait loci (qtls) for heading date and plant height in cultivated rice (oryza sativa l.).'lemont' and 'teqing' are both semidwarf rice varieties that differ in heading date by only 6 days. however, when 'lemont' and 'teqing' are crossed there is transgressive segregation for both heading date (hd) and plant height (ph). by testing 2418 f4 lines with 113 well-distributed rflp markers, we identified and mapped chromosomal regions that were largely responsible for this transgressive segregation. qhd3a, a qtl from 'lemont' that gives 8 days earlier heading, was identified on chromosome ...199524169788
anthocyanin pathway in rice (oryza sativa l): identification of a mutant showing dominant inhibition of anthocyanins in leaf and accumulation of proanthocyanidins in pericarp.the present study has surveyed a collection of indica rice (oryza sativa) lines for tissue-specific anthocyanin pigmentation pattern, which has also been used for a genetically meaningful classification. this classification helped predict probable genotypes of rice lines and, in the process, a leaf blade-specific dominant inhibitor of pigmentation (ilb) was predicted and its presence later confirmed in two lines. we ascribe most tissue-specific accumulation of anthocyanins to the presence of a d ...199524169778
expression of rice osh1 gene is localized in developing vascular strands and its ectopic expression in transgenic rice causes altered morphology of leaf.transgenic rice plants (oryza sativa cv. nipponbare) carrying 1 or 2 copies of a rice homeobox gene, osh1, under the control of the camv 35s promoter were generated. the transgene caused altered morphology of leaf, such as ligule-replacement and abnormal division of sclerenchyma cells. the phenotype of these leaves resembles that of maize leaf morphological mutant, knotted 1, which is caused by duplication of the kn1 gene (veit et al., 1990). the in situ hybridization analysis has revealed that ...199524185596
variation in protein and rna synthesis activity in isolated mitochondria of the developing rice (oryza sativa l.) panicle.we have studied variation in mitochondrial protein and rna synthesis during the development of a specialized rice (oryza sativa l.) reproductive organ in a bacteria-free environment. mitochondria were prepared from the maturing panicle during microsporogenesis when meiosis occurred and from etiolated seedlings at two growth stages. we found (1) that there was no discernible qualitative difference among the polypeptides synthesized by these three mitochondrial samples; (2) that the quantity of pr ...199524173071
the effects of selection for sodium transport and of selection for agronomic characteristics upon salt resistance in rice (oryza sativa l.).a multiple cross was constructed with the aim of combining component traits for the complex salinity resistance character. the aim was to combine donors for physiological traits with the agronomically desirable semidwarf/intermediate plant type and with the overall salinity resistance of the traditional tall land races. we report a study of selection strategies in the resulting breeding population. the effects of early selection for agronomic traits and early selection for low sodium transport w ...199524173070
the identification of duplicate accessions within a rice germplasm collection using rapd analysis.a set of accessions of oryza sativa from the international rice research institute (philippines) that included known and suspected duplicates as well as closely related germplasm has been subjected to rapd analysis. the number of primers, the number of polymorphic bands and the total number of bands were determined that will allow the accurate discrimination of these categories of accessions, including the identification of true and suspected duplicates. two procedures have been described that c ...199524173061
a chromosome 5-specific repetitive dna sequence in rice (oryza sativa l).repetitive dna sequences in the rice genome comprise more than half of the nuclear dna. the isolation and characterization of these repetitive dna sequences should lead to a better understanding of rice chromosome structure and genome organization. we report here the characterization and chromosome localization of a chromosome 5-specific repetitive dna sequence. this repetitive dna sequence was estimated to have at least 900 copies. dna sequence analysis of three genomic clones which contain the ...199524173043
association of morphological and rflp markers in rice (oryza sativa l.).seventeen morphological marker genes were associated with restriction fragment length polymorphism markers in rice by using four f2 populations, each segregating for a few observable traits, and 14 near isogenic lines (nils), each containing one morphological mutant gene. the location of five genes was confirmed on the basis of f2 analysis: purple hull (pr) (16.8 +/- 7.9 cm away from rg163 on chromosome 4); phenol staining (ph) (20.8 +/- 8.4 cm away from rg163 on chromosome 4); glabrous leaf and ...199518470190
effect of anoxia on carbohydrate metabolism in rice seedlings.the metabolism of carbohydrates was investigated in rice (oryza sativa l.) seedlings grown under anoxia. two phases can be recognized in the utilization of carbohydrates: during the first days of germination under anoxia, the metabolism of sugars is mainly degradative, whereas after the induction of [alpha]-amylase (ec 3.2.1.1) has taken place, the increased presence of glucose and sucrose indicates that both starch degradation and sucrose synthesis operate. the analysis of the enzymes involved ...199512228505
presence of a chloroplast dna sequence in an autonomous circular dna molecule in cultured rice cells (oryza sativa l).sequence analysis of twelve dna fragments, which had previously been found to be extensively amplified in suspension-cultured rice cells, revealed that two of them, isolated on plasmids designated pe10 and pe11, have sequences identical to distinct regions of chloroplast dna (ct-dna). both sequences are part of an extrachromosomal circular dna molecule (ecd). the molecular structure of the ecd was investigated by a combination of restriction analysis, standard and pulsed-field gel electrophoresi ...19957640893
a novel stress-inducible metallothionein-like gene from rice.a novel rice genomic sequence encoding coding segments homologous to other metallothionein-like genes was isolated from oryza sativa genomic library. this sequence, hereby designated as rgmt (rice genomic metallothionein-like gene), consists of two exons and one intron. from the coding sequence, it is predicted that rgmt encodes one protein of 74 amino acids. differential expression of rgmt in rice plants was observed as mature transcripts were more abundant in roots than in leaves and sheaths. ...19957632910
a rice membrane calcium-dependent protein kinase is induced by gibberellin.a rice (oryza sativa) seed plasma-membrane calcium-dependent serine/threonine protein kinase (cdpk) has been partially purified. comparing results in seeds that were treated with and without the plant hormone gibberellin (ga) for 10 min showed that rice cdpk was highly induced by ga. after separating solubilized membrane proteins by sodium dodecyl sulfate-gel electrophoresis, followed by renaturation, a radiolabeled phosphoprotein band of approximately 58 kd was detected, and it was apparently p ...19957610167
structure, organization, and chromosomal location of the gene encoding a form of rice soluble starch synthase.a rice (oryza sativa l.) genomic clone encoding the gene for a form of soluble starch synthase (sss1) and its 5'- and 3'-flanking regions has been isolated and sequenced. the sss1 gene contained 15 exons interrupted by 14 introns. the exon/intron organization of the sss1 gene was divergent from that of the rice waxy gene coding for granule-bound starch synthase, thus suggesting that the sss1 and granule-bound starch synthase genes have evolved from an ancestral gene in a different way or that th ...19957610165
vacuolar h(+)-translocating pyrophosphatase is induced by anoxia or chilling in seedlings of rice.the present study was undertaken to determine whether vacuolar h(+)-pyrophosphatase (v-ppase) might replace vacuolar h(+)-atpase under energy stress due to anoxia or chilling in anoxia-tolerant species such as rice (oryza sativa l.) and corn (zea mays l.). the relative transcript level of v-ppase in rice seedlings, like that of alcohol dehydrogenase 1, increased greatly under anoxia and declined again when the seedlings were returned to air. however, the distribution of transcripts in root, shoo ...19957610161
the genomic organization of the gene encoding a nitrate-inducible ferredoxin-nadp+ oxidoreductase from rice roots.a genomic clone of the gene encoding a nitrate-inducible ferredoxin-nadp+ oxidoreductase (fnr) from rice (oryza sativa l.) roots has been isolated and its nucleotide sequence determined. the clone contains 3897 nucleotides of the gene which consists of six exons interrupted by five introns. the transcription start site was determined by primer extension analysis which locates 64 bp upstream of the atg translation initiation codon. the 5'-flanking region contains canonical tata- and caat-boxes, a ...19957748889
identification of a set of rflp probes for subspecies differentiation in oryza sativa l.sixty-eight indica-japonica tester-differentiating rflp probes were tested in seven indica and seven japonica varieties of rice (oryza sativa l.) with four enzyme digestions (ecori, ecorv, hindiii and drai). twenty-one dna clones were isolated as indica-japonica subspecies-differentiating probes. a set of 13 probes was established as core probes for subspecies differentiation and a pooled blotting analysis was carried out to facilitate the application of rflp in rice genetics and breeding practi ...199524172933
rice anther culture: callus initiation and androclonal variation in progenies of regenerated plants.anthers from rice (oryza sativa l.) subspecies japonica initiated more callus than their indica or indica x japonica counterparts. a mild stress, either by slow desiccation or heat shock, prior to the plating of anthers enhanced the ability to initiate callus. slow dessication of anthers enhanced the ability of the japonica anthers to initiate callus even in medium that was supplemented with nacl. the ability to initiate callus by the anthers plated on nacl-supplemented medium decreased as the n ...199524185451
seed dormancy in red rice (oryza sativa) (ix. embryo fructose-2,6-bisphosphate during dormancy breaking and subsequent germination).fructose-2,6-bisphosphate (fru-2,6-bisp) was evaluated as a potential marker for the dormancy-breaking phase or the germination phase before pericarp splitting in red rice (oryza sativa). during 4 h of imbibition at 30[deg]c, fru-2,6-bisp of dehulled dormant and nondormant seeds increased to 0.26 and 0.38 pmol embryo-1, respectively. in nondormant seeds, embryo fru-2,6-bisp content remained stable until the onset of pericarp splitting (12 h) and increased rapidly thereafter. in dormant seeds, fr ...199512228440
bamhi and hindiii repetitive dna families in the rice genome.in this paper we describe a novel method of cloning representative members of different repetitive dna families based on the screening of a rice (oryza sativa) genomic library using dna from different c0t fractions as probes. two genomic clones, which represent two different repetitive dna families in rice, were isolated by this method and have been characterized. their nucleotide sequences, copy numbers, distributions in major rice genome types, methylation patterns, and chromosomal localizatio ...19957774793
gibberellin promotes histone h1 kinase activity and the expression of cdc2 and cyclin genes during the induction of rapid growth in deepwater rice internodes.partial submergence or treatment with either ethylene or gibberellin (ga) promotes rapid internodal growth in deepwater rice (oryza sativa l.). earlier work has shown that ga is the immediate hormonal signal for this growth response, which involves induction of the cell cycle at the g2/m phase transition and subsequent enhancement in the rate of dna synthesis. in all eukaryotes, onset of mitosis is regulated by the p34cdc2/cdc28 protein kinase, whose activity is assayed by in vitro phosphorylati ...19957742859
structural changes in the plastid dna of rice (oryza sativa l.) during tissue culture.to investigate the rearrangement of the plastid genome during tissue culture, dna from rice callus lines, which had been derived individually from single protoplasts isolated from seed or pollen callus (protoclones), was analyzed by southern hybridization with rice chloroplast dna (ctdna) clones as probes. among 44 long-term cultured protoclones, maintained for 4, 8 or 11 years, 28 contained plastid dna (ptdna) from which portions had been deleted. the ptdna of all protoclones that had been main ...199524173926
molecular cloning of the gene (sodcc1) that encodes a cytosolic copper/zinc-superoxide dismutase from rice (oryza sativa l.). 19957724677
use of rapd for the study of diversity within plant germplasm collections.as part of the development of a molecular toolkit for the study of diversity within large plant germplasm collections, rapd technology has been applied to accessions of rice (oryza sativa) obtained from the major world collection held at irri (the international rice research institute) which supplies germplasm to breeders. methods for the speedy extraction of dna representative of a rice accession, its amplification by pcr to reveal reproducible products, and the analysis of the banding data usi ...19957706109
totipotency of coleoptile tissue in indica rice (oryza sativa l. cv. ch 1039).embryogenic and non-embryogenic calluses were induced from 3,4,5 and 7d old coleoptile segments of indica rice (oryza sativa l. cv. ch 1039). compact, globular, yellow and creamy embryogenic and white friable non-embryogenic callus arose from the cut end and entire length of the coleoptile segments. murashige and skoog's (ms) medium supplemented with 2.5mg/1 2,4-d was used as callus induction medium. plant regeneration from coleoptile segments occurred with the transfer of embryogenic callus to ...199524190304
transient expression of gus gene in intact seed embryos of indica rice after electroporation-mediated gene delivery.two-day-old germinating intact seed embryos of oryza sativa variety basmati 370 were electroporated with a view to examine suitability of this system for gene delivery. the experiments were done with a plasmid having gus gene under the control of camv 35s promoter. spectrofluorophotometric gus assay revealed high activity of the introduced gene when embryos were given three electrical pulses at 1600 v cm(-1) and 100 μf capacitance with a pulse length of 75 ms. additionally, histochemical localiz ...199524190298
cryopreserved callus: a source of protoplasts for rice transformation.we cryopreserved whole rice calli (oryza sativa l cv taipei 309) to investigate the ability of the surviving cells to regenerate plants and yield protoplasts competent for genetic transformation. four out of six callus lines cryopreserved after four months in culture contained small sectors able to continue cell division and subsequently regenerate fertile plants. both cryopreservation efficiency and regeneration ability decreased when using eight month old cultures. high yields of protoplasts w ...199524190297
plant regeneration from protoplasts of cytoplasmic male sterile lines of rice (oryza sativa l.).this study compared plant regeneration from protoplasts isolated from suspension cultures of threejaponica rice (oryza sativa l.) lines with different male sterile cytoplasms. more than 180 green plants were regenerated from protoplasts from 5-8 month old suspensions of ir58024a, a line with the wa type of cytoplasmic male sterility (cms). about 40% of the calli recovered from protoplasts produced green plants. shuangbaia (bt type of cms) and tai2a (dian i type of cms), both from zhejiang provin ...199524185659
evidence for the involvement of glycanase activities in the dissociation of cortical cell walls during the emergence of callus from rice root tissues in the presence of 2,4-d.nojirimycin bisulfite andp-nitrophenyl-1-thio-ß-d-glucoside, potent inhibitors of ß-glucanase, suppressed cortical dissociation and callus growth in rice roots (oryza sativa l. cv. sasanishiki) in the presence of 2,4-d, with resultant suppression of the emergence of callus clumps from the interior of root tissues. these sugar analogs inhibited the 2,4-d-induced increase in the elastic and plastic compliance of cell walls but did not affect oxygen uptake by root explants in the presence of 2,4-d. ...199524185652
suspension and protoplast culture of u.s. rice cultivars.efficient protoplast culture and plant regeneration of five u.s. rice cultivars (oryza sativa l.) - mercury, lacassine, maybelle, cypress, and lemont - were obtained from suspension cells maintained in modified general medium. embryogenic suspension cells were developed from calli grown on the original callus induction medium for 10-20 weeks without subculture. weekly subculture of the suspensions for five to eight weeks yielded cells suitable for protoplast isolation. after 2 weeks, rate of col ...199524185650
the physical location of fourteen rflp markers in rice (oryza sativa l.).a biotin-labeled in situ hybridization technique was used in order to physically map rflp markers to the chromosomes of rice (oryza sativa l.). fourteen rflp markers, associated with the ends of the linkage groups on rice chromosomes 7, 8, 11, 12, were physically mapped onto specific regions of the chromosomes. the average detection rate of in situ hybridization was 5.91%. the markers were located on seven different chromosome arms. ten of the fourteen markers were distributed near the chromosom ...199524173791
effects of air pollution on rice yield in the pakistan punjab.a study using open-top chambers ventilated with ambient or charcoal filtered air in the vicinity of lahore, pakistan demonstrated reductions of 42% and 37% in the grain yield of two cultivars of rice (oryza sativa l.). this yield reduction was primarily due to the reduction in mean panicle number per plant, although significant effects of filtration on 1000 grain weight and the number of filled grains per panicle were also detected. the 6-h daily mean o(3) concentrations were only 10-20 nl litre ...199515091465
developmental and hormonal regulation of rice [alpha]-amylase(ramy1a)-gusa fusion genes in transgenic rice seeds.transgenic seeds of rice (oryza sativa l.) were used to investigate temporal, spatial, and hormonal regulation of a rice [alpha]-amylase gene, ramy1a. two overlapping segments of the ramy1a promoter were fused to the coding region of the bacterial reporter gene, gusa. the resulting promoter-gusa fusions, pe4/gus (-232 to +31) and ph4/gus (-748 to +31), were used separately to transform rice protoplasts. [beta]-glucuronidase (gus) activity was detected in germinated transgenic seeds, although the ...199512228339
characterization of a rice gene family encoding root-specific proteins.two cdna clones (rcc2 and rcc3) corresponding to mrnas highly expressed only in root tissues of rice (oryza sativa l.) seedlings were characterized. respectively, they encode polypeptides of 146 (14.5 kda) and 133 amino acids (13.4 kda) that share high (> 70%) sequence similarity with a polypeptide encoded by a cdna (zrp3) encoding an mrna preferentially expressed in young maize roots. genomic dna blot analysis revealed that they are members of a small gene family and rcg2, the gene correspondin ...19957888615
molecular and physiological responses to abscisic acid and salts in roots of salt-sensitive and salt-tolerant indica rice varieties.the indica rice (oryza sativa l.) varieties pokkali and nona bokra are well-known salt tolerance donors in classical breeding. in an attempt to understand the molecular basis of their tolerance, physiological and gene expression studies were initiated. the effect of abscisic acid (aba) on total proteins in roots from 12-d-old seedlings of pokkali, nona bokra, and the salt-sensitive cultivar taichung n1 were analyzed on two-dimensional gels. the abundance of aba-induced proteins was highest in th ...19957870812
polymorphism and genetic relatedness among wild and cultivated rice species determined by ap-pcr analysis.we have applied the arbitrarily primed polymerase chain reaction (ap-pcr) technique to the analysis of the relationships among six japonica and indica cultivars, and four wild species of rice. chosen were four primers of arbitrary sequence that gave multiple amplification products when rice dna was used as template. among a total of 50 bands scored, 44 were polymorphic, which was sufficient to distinguish the species used in this study. it is apparent from the comparisons of genetic distances th ...19957558882
an epitope of rice threonine- and hydroxyproline-rich glycoprotein is common to cell wall and hydrophobic plasma-membrane glycoproteins.a monoclonal antibody, lm1, has been derived that has a high affinity for an epitope of hydroxyproline-rich glycoproteins (hrgps). in suspension-cultured rice (oryza sativa l.) cells the epitope is carried by three major proteins with different biochemical properties. the most abundant is the 95-kda extracellular rice extensin, a threonine- and hydroxyproline-rich glycoprotein (thrgp) occurring in the cell wall and secreted into the medium. this thrgp can be selectively oxidatively cross-linked ...19957544182
hybrid rice (oryza sativa l.): identification and parentage determination by rapd fingerprinting.dna from three families of rice plants selected in northern china (each comprising the male sterile, the restorer, the hybrid f1 and the maintainer lines) has been extracted and amplified by pcr with different random dna primers (rapd analysis). then, dna has been analysed by agarose gel electrophoresis and dna bands scored as present or absent. the generated matrices are reproducible and amenable for identification of each single plant line. thus, rapd fingerprinting of the inbred parental line ...199424192876
expression of the enzymes of nitrate reduction during the anaerobic germination of rice.during the anaerobic germination of rice (oryza sativa l.), nitrate is translocated from the caryopsis and assimilated into the coleoptile (r. reggiani, m. mattana, n. aurisano, a. bertani [1993] plant cell physiol 34: 379-383). using antibodies against nitrate and nitrite reductases, proteins with the expected molecular mass were recognized by western blot analysis in extracts from 8-d-old rice coleoptiles. both enzymes are de novo synthesized in 6- to 8-d-old seedlings, as shown by immunopreci ...199412232434
identification and characterization of a family of genes for the plasma membrane h(+)-atpase of oryza sativa l.a cdna clone (cosa2) encoding a plasma membrane h(+)-atpase was isolated from rice. southern blot analysis indicated that the genes that corresponds to cosa2 was different from that to cosa1. northern blots revealed osa2 mrna in roots, calli and shoots. osa1 transcripts were detected only by rt-pcr in these tissues.19947697296
protein phosphatase inhibitors enhance the expression of an alpha-amylase gene, alpha amy3, in cultured rice cells.a rice (oryza sativa l.) gene for alpha-amylase, alpha amy3, was strongly and rapidly induced by treatment of suspension-cultured cells with okadaic acid (oa), a potent and specific inhibitor of protein serine/threonine phosphatases 1 and 2a. the massive accumulation of alpha amy3 mrna in response to oa treatment was due to the stimulation of gene transcription and a partial stabilization of this mrna. this induction of alpha amy3 message by oa occurred even though cellular protein synthesis was ...19947999117
differential transcript levels of genes associated with glycolysis and alcohol fermentation in rice plants (oryza sativa l.) under submergence stress.expression of genes encoding enzymes involved in specialized metabolic pathways is assumed to be regulated coordinately to maintain homeostasis in plant cells. we analyzed transcript levels of rice (oryza sativa l.) genes associated with glycolysis and alcohol fermentation under submergence stress. when each transcript was quantified at several times, two types (i and ii) of mrna accumulation were observed in response to submergence stress. transcripts of type i genes reached a maximum after 24 ...199412232382
molecular changes of organelle dna sequences in rice through dedifferentiation, long-term culture, or the morphogenesis process.callus-specific rearranged dna in rice (oryza sativa l.) was isolated by in-gel reassociation procedure. southern hybridization experiments revealed that some clones were amplified significantly in primary callus induced from scutellum tissue. rapid amplification of these clones was observed within 2 days after plating seeds onto callus-induction medium containing 2,4-d. naa gave no significant effect on dna amplification event. colony formation process from isolated protoplasts and plant regene ...19948000003
genetic analysis of tolerance for phosphorous deficiency in rice (oryza sativa l.).the inheritance of phosphorous (p) - deficiency tolerance in rice was investigated by a sevenparent diallel. the parent materials involved were four p-efficient (ir20, ir54, ir28, and mahsuri), one moderately p-efficient (tn1), and two p-inefficient (ir31406333-1 and ir34686-179-1-2-1), genotypes. relative tilering ability (rta) under p-deficient and p-supplemented soil conditions was the parameter used in determining the tolerance level of the different genotypes. diallel graph analysis reveale ...199424177847
sequence of a cdna from oryza sativa (l.) encoding the pyruvate decarboxylase 1 gene. 19947991697
a group of chromosomal proteins is specifically released by spermine and loses dna-binding activity upon phosphorylation.biologically relevant concentrations as low as 500 microm spermine led to the specific release of chromatin-associated proteins from nuclei of rice (oryza sativa) seedlings. using a southwestern technique, it was shown that several of these proteins bind dna. this affinity was lost upon in organello phosphorylation by an endogenous kinase. the effect of spermine was very specific. spermidine was far less effective and putrescine was essentially ineffective in releasing these proteins. the most a ...19947991684
transcribed repetitive dna sequences in telomeric regions of rice (oryza sativa).we have isolated and characterized from rice three repetitive dna sequences, os48, osc-567, and osg3-430. our results indicate that these repetitive sequences are highly transcribed, and transcripts complementary to both strands of the os48 family of sequences account for up to 3% of the total cellular rna. pulsed-field gel electrophoresis, restriction mapping, and dna sequence analyses have revealed a complex pattern of structural organization of the three families of repetitive sequences. os48 ...19947948882
induction of chilling resistance by water stress, and cdna sequence analysis and expression of water stress-regulated genes in rice.exposure of seedlings of a chilling-sensitive variety of rice (oryza sativa l. cv. wasetoittu) to water stress (0.5 m mannitol, 30 min) at room temperature induced a degree of chilling resistance. no such resistance was induced by exogenous abscisic acid (aba) application (10 microm, 60 min). upon short-term water stress, new transcripts were expressed in both seedlings and suspension-cultured cells. we suggest that the genes induced by short-term water stress, and not those induced by aba, are ...19947948880
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