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Sample records for accumulating rice mutant

  1. Induced mutants for rice functional genomics

    Induced mutations have been playing important roles in both crop germplasm enhancement and new variety development. With the completion of the rice genome sequence, the study on functional genomics in rice has become a major task. Construction of rice mutant library is an essential approach for rice functional genomics study. This paper briefly reviewed several common techniques for generation of rice mutant library and its application in rice functional research, taking examples of developing rice chloroplast development related mutant library to provide the basic materials for functional genes cloning. A rice Chlorophyll (Chl) deficient mutant, yellow-green leaf1 (ygl1), was isolated, which showed yellow-green leaves in young plants with decreased Chl synthesis, increased level of tetrapyrrole intermediates, and delayed chloroplast development. Genetic analysis demonstrated that the phenotype of ygl1 was caused by a recessive mutation in a nuclear gene. The ygl1 locus was mapped to chromosome 5. A missense mutation was found in a highly conserved residue of YGL1 in the ygl1 mutant, resulting in reduction of the enzymatic activity. Another green-revertible albino leaf (gral) mutant involved in chloroplast development was screened from a M2 population induced by 300Gy 60Co gamma rays irradiation to the seeds of rice male sterile line PA64S with the collaboration of Zhejiang University. The mutant seedling leaves exhibit albino firstly but turn to normal green after the sixth leaf extended thoroughly. Systematical research including photosynthetic pigment, chloroplast microscopic observation and gene cloning was carried out on the gral mutant. (author)

  2. Rice mutant cultivar SCS114 Andosan

    The development process and its yield, quality performance of the mutant rice variety SCS Andosan 114 was described. SCS Andosan 114 was selected from the mutant progeny of IR 841 after treatment of 150 Gy gamma rays; It had a 7.4 ∼ 9.6% yield increase over IR 841 and a higher amylase content (28%) than IR 841 (19%). The mutant variety also showed high tolerance to iron toxicity and resistance to blast disease. (author)

  3. Induction and analysis of rice lesion mimic mutant

    A lesion mimic mutant of rice (Oryza sativa L.), named as cer1, was induced from a japonic rice variety Katy with 1.0% ethyl methane-sulfonate (EMS) treatment. Phenotype of mutant was comparatively characterized along with the original parent Katy. The height, the number of tillers, one-thousand-grain weight of mutant was significantly reduced than those of Katy. Genetic analysis indicated that the mutation is controlled by single recessive gene. Lesion mimic phenotype of LmmKaty was rapidly induced by virulent M. grisea isolates or by avirulent isolates only at high levels of inoculum. Autofluorescence (a sign of an active defense response) was visible under ultraviolet light 24 h after localized inoculation in the incompatible interaction whereas, autofluorescence was not evident in the compatible interaction. Autofluorescence was also observed in LmmKaty 20 h after pathogen inoculation, thus indicating that rapid cell death is a mechanism of LmmKaty to restrict pathogen invasion. Rapid accumulation of defense related (DR) gene transcripts, phenylalanine ammonia lyase and β-glucanase, was observed beginning at 6 h and was obvious at 16 h and 24 h in an incompatible interaction. Rapid transcript accumulation of PR-1 and chitinase had occurred by 24 h after inoculation in an incompatible interaction. Accumulation of these transcripts was delayed in a compatible interaction. These results indicate that host active defense responses occur 24 h after pathogen inoculation and that LmmKaty exhibits enhanced resistance to M. grisea. (author)

  4. Induction of drought tolerant mutants of rice

    The ultimate goal of crop breeding is to develop varieties with a high yield potential and desirable agronomic characteristics. In Egypt, the most important qualities sought by breeders have been high yield potential, resistance to major diseases and insects, and improved grain and eating quality. However, breeding efforts should concentrate on varieties with the potential to minimize yield losses under unfavorable conditions such as drought, and to maximize yields when conditions are favorable. Rice (Oryza sativa L.) in Egypt is completely irrigated and a significant portion of the rice cultivated area is subject to water deficit resulting from an inadequate or insufficient irrigation supply. Drought tolerance is a complex trait in that it results from the interaction of histological and physiological characters of plant with environmental factors, both above-ground and under-ground. Accordingly, root characters are closely related to drought tolerance. Little attention has been paid in Egyptian breeding programs to root characters and their relation to shoot characters. Furthermore, induced mutations are considered as one of the most important methods to induce useful mutants, especially with improved root characters, to overcome the drought problem. The present investigation aimed to study the effect of different doses of gamma rays on several characters of three Egyptian rice varieties, i.e. 'Giza 171', 'Giza 175' and 'Giza 176' and to induce one or more mutants possessing drought tolerance

  5. High yielding early mutant of Mashuri rice variety

    Mashuri mutant was evolved by treating a Malaysian popular rice variety (Mashuri) with gamma rays. This mutant differed from its parent by exhibiting short duration (25 days less), short height (14 cm less) and blast resistance with all other desirable characters of parent type. These desirable changes brought by mutation made the mutant line suitable for the rabi season. (author)

  6. Sodium accumulation in rice and quinoa

    Full text: Sensitivity to salinity is often attributed to excessive accumulation of Na+ ions in leaf cells. This implies that screening for low Na+ accumulation should result in enhanced tolerance to salt. While this is generally true, there are a number of examples where Na+ accumulation is not the only factor. In rice (Oryza sativa) there is good evidence linking genetically-determined Na+ accumulation with tolerance to salinity, but there are other factors that should be considered, including Cl- accumulation and the inter- and intra-cellular distribution of solutes. In quinoa (Chenopodium quinoa) There are large varietal differences in Na+ accumulation, but smaller differences in salt tolerance. We have studied the genetics of salinity responses in two cultivars of rice, Co39 and Moroberekan. The latter accumulates more Na+ than Co39 and many other rice varieties. Experiments at a range of salt concentrations and with varying Na: Ca ratios showed that Na+ accumulation was initially quite low, but increased with time of exposure to salt. Part of the increase in Na+, and all of the observed increase in K+ concentrations, could be attributed to dehydration of the leaves. Measurements of leaf solute and water potentials indicated that solutes accumulated in the leaf apoplast. This resulted in reduced turgor and increased leaf rolling. Concentrations of Cl- in the leaves were several times higher than those of Na+. QTL analysis of a hybrid population derived from these varieties revealed a major QTL for leaf Na+ accumulation on chromosome 1 at a position where QTL for salt tolerance and Na+ uptake have been identified by other groups. No QTL were identified for Cl- accumulation. Is rice relatively salt sensitive because it accumulates low concentrations of Na+ under genetic control, or is Cl- (present at much higher concentrations) responsible for salt damage. We are looking for rice accessions that differ in Cl- accumulation to find Cl- QTL. Perhaps it does not

  7. The genetics analysis of rice mutant R917 with resistance to rice blast (pyricularia oryza)

    Rice mutant R917 with resistance to rice blast was selected by induced mutation with irradiation. The F2 segregation of R917/NF6, XS11, XS861 crosses with resistance to rice blast ZB15, ZC13, ZE3 showed that the rice blast resistance is controlled by one dominant gene. The identification of the disease resistance for the progenies of R917 crosses with XS11, XS861 showed that R917 could be used as a good material for resistance to rice blast in rice breeding

  8. Promising mutant variety of rice evolved through gamma irradiation

    Rice occupies a major share in crop production in the Chotanagpur plateau of Bihar State. Uplands are roughly 40% in area where traditional low yielding rice, known as ''gora'' is cultivated as directly sown crop. Despite introduction of high yielding rice varieties, gora group of rices continue to prevail. It is therefore desired to increase the productivity level of the gora rice by mutation breeding. One such mutant known as ''gora mutant'' was obtained through gamma irradiation (10 kR) of variety Brown gora. The maturity of both parent and mutant remaining constant (ie. 100 days), there is some improvement in other characteristics like plant height, tillering capacity and kernel character. The parent being tall, shy in tillering and red bold kernel, the mutant has dwarfish characteristics, profuse tillering habit and white kernel with fine grains. The yielding capacity of mutant derivative is 30-40% higher than the parent Brown gora. This variety is in pre-release stage, and the farmers have taken great liking for it. (author)

  9. Accumulation and transport mechanisms of arsenic in rice

    Islam, Md. Rafiqul; Kamiya, Takehiro; Uraguchi, Shimpei; Fujiwara, Toru

    2009-01-01

    Both species of arsenic (As), arsenate and arsenite are highly toxic to plants. Arsenic contamination is a major problem in Southeast Asia particularly in Bangladesh and West Bengal. In these countries, As-contaminated groundwater is widely used for irrigating rice in dry season that results in elevated As accumulation in soils and in rice grain and straw. So it is important for understanding the accumulation and transport mechanisms of arsenic in rice. We monitored increased arsenic content ...

  10. Effect of N level on rice yield, nitrogen accumulation and rice blast occurrence under rice intercropping system

    Tang, Li; Lu, Guoli; Cu, Yiou; Zhang, Chaochun; Zhang, Fusuo; Zheng, Yi

    2009-01-01

    Abstract: Plant N nutrition plays an important role on plant metabolisms and crop diseases resistance. Intercropping can increase grain yields greatly and provide an ecological approach to disease control. Field trails of using two rice varieties with different resistance to rice blast, Huangkenuo (HKN) and Hexi-41(HX41), was carried out to investigate the effect of nitrogen fertilizer rate on rice yield, nitrogen accumulation and rice blast occurrence under rice mono-cropping and intercroppi...

  11. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas. PMID:26974480

  12. Selection Of Drought Resistant Mutants In Rice Using DNA Markers

    In recent years, the marker - assisted selection (MAS) strategy have been used for selection of traits that are difficult and costly performed measurement and score. Selection for a well-developed root system could improve the drought resistance of rice as the plant would avoid water stress by absorbing water from the soil. There were several reports on map construction and identification of the markers tightly linked to morphological and physiological traits related to drought resistance in rice, in particular, root traits in upland and lowland rice (Champoux et al., 1995; Ray et al., 1996; Price et al., 1997, 2000; Yadav et al., 1997). In this report, we present the results on selection of drought resistance mutants in rice using the DNA markers tightly linked to root traits favorable for drought resistance. The mutant rice lines were obtained from irradiated seeds and calluses by gamma ray. The selection was performed at M2 mutants using the DNA markers linked to maximum root length (MRL), root weight to shoot weight ratio (RW/SR), and weight of deep root to shoot weight ratio (DRW/SR). The obtained results showed that there were many lines possessed drought resistant markers. In addition, there is a number of lines have altered genome. Several lines having drought markers proved to be more resistant to drought in green-house test. These lines could be useful for further test and development of drought resistant varieties. (author)

  13. Early ripening mutants induced by colchicine in rice

    CAIGuohai; YANWanchao; CAOXin

    1993-01-01

    In 1981-1983, the frequency and range of the mutants induced by colchicine were investigated in M2 and M3 of two indica-rice cultivars.Seedlings of M2 and M3 were treated with 0.05% colchicine solution at 4-5 leaf stage.

  14. A Bentazon and Sulfonylurea-sensitive Mutant in Rice and its Application in Hybrid Rice

    A rice bentazon-lethal mutant 8077S obtained by radiation, is being utilized in developing new hybrid rice systems. Genetic analysis revealed that the bentazon-lethal mutant was controlled by a single recessive gene, which is named bel. The mutant can be killed at the seedling stage by bentazon with a lethal dosage at 300 mg/l or above, while this dosage is safe for its F1 hybrids and all other normal rice. This mutant is also sensitive to all the tested sulfonylurea herbicides and this sensitivity is also controlled by bel. Interestingly, another rice bentazon-lethal mutant Norin8m also obtained by radiation in Japan, was controlled by the allelic locus of bel, which is named as bsl. These two mutant genes were cloned by map-based cloning. Both mutant alleles had a single-base deletion respectively. There is a G deletion in the bel. and a C deletion in the bsl. The wild-type gene bel. encodes a novel cytochrome P450 monooxgenase, named CYP81A6. Otherwise, the use of photo-thermogenic male sterility (P/TGMS) system in two-line hybrid rice breeding is affected greatly by the sterility instability of P/TGMS lines caused by temperature fluctuation beyond their critical temperatures for fertility reversion. To prevent the hybrid seed contamination, we have developed three bentazon-lethal P/TGMS lines using 8077S by backcross and three new hybrid rice varieties using these P/TGMS lines had been registered. When these P/TGMS lines selfed by temperature fluctuation, the seedlings from the selfed seeds can be killed by spraying bentazon at seedling stage but the hybrid seedlings are safety. These new hybrid rice varieties have been cultivated in five provinces in China. (author)

  15. Induction and identification of japonica rice mutants for drought tolerance

    Two mutants G1 and G2 were identified and selected from M6 after 200 Gy 60Co γ-rays treatment to pure dry seeds of a Japonica rice cultivar Zhejing 20. These two lines showed significantly higher drought tolerance than their parent Zhejing 20, and moderately higher than Brazil upland rice IAPAR-9 at both vegetative growing stage observed in Hangzhou and reproductive growing stage in Hainan. It was also demonstrated from the separate field tests that two lines performed very well in both water-field and upland-soil, implicating that the two mutants have very good adaptability to water-field and upland-soil. The high yielding line G1 can be applied directly to immediate high yield rice breeding while the relatively low yielding line G2 could be used as a new source of drought tolerance in the future breeding programs. (authors)

  16. Metabolite profiling of induced mutants of rice and soybean

    The study objects of the investigation were two low phytic acid (lpa) rice (Os-lpa-XS110-1, Os-lpa-XS110-2) and soybean (Gm-lpa-TW-75-1, Gm-lpa-ZC-2) mutants generated by irradiation. The aim was to compare these mutants to the corresponding wild-types by means of capillary gas chromatography metabolite profiling and to explore the usefulness of this approach to assist in the elucidation of the types of mutation resulting in the reduced contents of phytic acid. Metabolite profiling aspires to provide a comprehensive picture of the metabolites present in biological systems. It aims at extracting, detecting, identifying, and quantifying a broad spectrum of compounds in a single sample to provide a deeper insight into complex biological systems. The extraction and fractionation method used in the study allowed a comprehensive coverage of a broad spectrum of low molecular weight metabolites ranging from lipophilic (fatty acids methyl esters, hydrocarbons, free fatty acids, sterols, tocopherols) to hydrophilic (sugars, sugar alcohols, organic acids, amino acids) compounds. For rice, considerable amounts of the peaks detected were statistically significantly different between wild-types and lpa mutants within one field trial. However, only a few of these differences could be consistently observed in all analyzed field trials indicating a strong influence of the biological variability. Metabolites shown to be consistently statistically significantly different between wild-type and lpa rice mutants were found to be closely related to the biogenetic pathways leading to phytic acid. This allowed a prediction of the mutation targets for the lpa rice mutants in the biosynthetic pathway of phytic acid. Similar effects, e.g. clustering of wild-types and lpa mutants on the basis of metabolite profiling data, were observed for soybean. (author)

  17. A dominant semi dwarf mutant in rice

    2002-01-01

    @@ In the winter of 1997, a semi dwarf mutant was found in the F6 population of M9056/ R8018 xuan in Hainan Province. In the spring of 1998, the seeds were sown in Hefei, Anhui Province and the plant height of the population was measured at maturity.

  18. Mutation induction and evaluation of high yield rice mutants

    The successful use of plant breeding for improving crops requires the existence of genetic variation of useful traits. Unfortunately, the desired variation is often lacking. However, radiation has been used to induce mutations and thereby generate genetic variation from which desired mutants may be selected. Mutation induction has become a proven way of creating variation within a crop variety. It offers the possibility of inducing desired attributes that either cannot be expressed in nature or have been lost during evolution. Rice is security food crop in Malaysia. Efforts were undertaken to enhance rice yield from 4.0 tones per hectare in 1995 to 5.5 tones per hectare in 2010. Proper management and good varieties are two factors that require for enhancing yield of rice. In this research, purified seeds of MR211 and MR219 were gamma irradiated at 100 to 400 Gray and sown for planting as M1 generation at MARDI experimental plot. The M2 population was sown in bulk with population size around 15,000 to 20,000 plants. Individual plant selection was carried out at maturity and each selected plant became a mutant line of M3 generation. Agronomic trial of M3 mutants lines were conducted in Mardi, Tanjung Karang, Selangor. About 115 of selected mutant lines were evaluated. Each row of those mutant lines were planted in two rows at planting distance of 25cm within and between rows. These mutant lines were visually observed and data were recorded in each of every mutant line. (Author)

  19. Identification of some Rice Mutants using Morphological and Molecular Methods

    This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, abu zaabal in order to verify four rice genotypes i.e sakha 102, giza 178, high yielding mutant (Ms 6) and high yielding mutant (MG 16). the (UPOV) rice descriptor was used to identify the germplasm morphologically .Molecular RAPD-PCR was used to identify genetic variability on the molecular level for the tested genotypes. 1- the results indicated that according to (UPOV) rice descriptor eight morphological traits were completely different between mutant Ms 6 in comparison with the parent sakha 102 and mut. MG 16 in comparison parent giza 178, the traits were ; stem thickness, stem length, panicle length, 1000-grain weight, grain length, grain width decorticated grain length and decorticated grain width. 2- using 10 arbitrary primers, through four rice genotypes on the molecular level using RAPD markers. the size of the amplified fragments were ranged from 0.201 to 2.036 k bp. two primers OPB-13 and OPB-16 showed no polymorphism among genotypes tested. 3- the total number of amplicons produced by the 8 polymorphic RAPD profiels was 66. the total number of monomorphic amplicons was 32. however, the total number of polymorphic amplicons was 34. 4- the percentage of polymorphism ranged from (22.22%) for primer OPA-18 to (90%) for primer OPB-11. 5-the highest genetic similarity (90.3%) was between sakha 102 and high yielding mut. (Ms 6). the genetic similarity (75.5%) was between giza 178 and high yielding mut.(MG 16). 6- one positive unique marker amplified by OPA-18 Primer identified the high yielding mutant Ms 6 but three positive unique markers amplified by OPB-17 primer and OPA-18 primer identified the high yielding mutant MG 16

  20. Metabolite Profiling of Induced Mutants of Rice and Soybean

    The low phytic acid (lpa) rice (Os-lpa-XS110-1, Os-lpa-XS110-2) and soybean (Gm-lpa-TW-75-1, Gm-lpa-ZC-2) mutants generated by γ-irradiation were studied, aimed at comparing these mutants to the corresponding wild-types by means of metabolite profiling based on capillary gas chromatography/mass spectrometry. The usefulness of this approach to assist in the elucidation of the types of mutation resulting in reduced contents of phytic acid should be explored. Metabolite profiling aspires to provide a comprehensive picture of the metabolites present in biological systems. It aims at extracting, detecting, identifying, and quantifying a broad spectrum of compounds in a single sample, to provide a deeper insight into complex biological systems. The extraction and fractionation method used allowed a comprehensive coverage of a broad spectrum of low molecular weight metabolites ranging from lipophilic (fatty acids methyl esters, hydrocarbons, free fatty acids, sterols, tocopherols) to hydrophilic (sugars, sugar alcohols, organic acids, amino acids) compounds. For rice, considerable amounts of the peaks detected were statistically significantly different between wild-types and lpa mutants grown in the same field trial. However, only a few of these differences could be consistently observed in all analyzed field trials, indicating a strong influence of the biological variability. Metabolites consistently shown to be significantly different between wild-type and lpa rice mutants, were found to be closely related to the biogenetic pathways leading to phytic acid. This allowed a prediction of the mutation targets for the lpa rice mutants in the biosynthetic pathway of phytic acid. Similar effects, i.e. statistically significantly different levels of metabolites closely related to the biosynthesis of phytic acid, were consistently observed for soybean. (author)

  1. Residues and accumulation of molinate in rice crops and aquatic weeds in the MUDA rice agroecosystem

    Plant and soil residue levels and its accumulation in rice crops and rice aquatic weed plants were studied. Molinate residue levels in rice, weeds and soil were not significantly different between the recycled and the non-recycled area, even though they were higher in the non-recycled area. In the rice plant, the residue level at 10 DAT (days after treatment) was significantly higher than 30 DAT in the recycled area. In rice aquatic weed plants, the residue level was significantly higher at 10 DAT as compared to 30 DAT in the non-recycled area. Molinate residue levels in soil at 10 DAT and 30 DAT were similar. Molinate accumulated (ratio of molinate concentration in plant over soil) more in the rice crop as compared to rice aquatic weeds at 10 DAT, in both the recycled and the non-recycled areas. (Author)

  2. Butyric acid tolerance of rice mutant M4 families

    Mauricio Marini Kopp

    2007-01-01

    Full Text Available Hydromorphic soils have a low drainage capacity and are used mainly for the cultivation of irrigated rice.This condition favors the development of anaerobic microorganisms that produce phytotoxic substances. The objective of thisstudy was to evaluate the response of rice mutants to the phytotoxicity caused by butyric acid under anaerobic conditions. Theexperiment consisted of four treatments arranged in a randomized block design. Plants of 40 families were grown in ahydroponic system and the measured variables were root length and length of aerial part (LAP, number of roots (NR androot dry matter (RDM and aerial part dry matter (DMAP. The analysis of variance was performed, the relative performancecalculated and linear regressions were fitted. Only the treatment effect for NR and effect of interaction for LAP were notsignificant. Root length was most affected by the acid and the regressions expressed positive as well as negative effects for acidtolerance in the mutant families.

  3. Transcriptomic analyses of space-induced rice mutants with enhanced susceptibility to rice blast

    Cheng, Zhenlong; Liu, Ming; Zhang, Meng; Hang, Xiaoming; Lei, Cailin; Sun, Yeqing

    Mutagenic factors of the space environment influence organisms in different aspects. To elucidate the transcriptomic effects of space flight, a space flight-induced rice mutant, 972-4, and its on-ground control, 972ck, were inoculated with rice blast pathogens. Compared to the control, the mutant exhibited reduced resistance to the rice blast pathogen CH45. Microarray technique was employed to analyze affected genes and revealed that 481 genes were expressed at higher levels in the mutant strain and 188 genes were expressed at higher levels in the control strain under normal growth conditions, indicating that transcriptomic changes of rice seeds are induced by the space environment. After inoculation with the rice blast pathogen CH45, however, 2680 genes were differentially expressed in 972ck and 1863 genes were differentially expressed in 972-4. In addition, disease evaluation indicated that the control strain 972ck is more resistant to the rice blast pathogen CH45 than mutant strain 972-4. In addition, genes in both strains that were co-regulated after blast inoculation account for only 36.8% and 53.3% of the genes expressed in 972ck and 972-4, respectively. A large percentage of blast-regulated genes were not consistently expressed in 972-4 and 972ck, and the mutant and control strains exhibit different gene expression patterns after blast inoculation. Interestingly, 84 genes constitutively expressed higher in 972ck were up-regulated by blast inoculation, and 105 genes that were expressed at constitutively higher levels in 972-4 were down-regulated by blast inoculation. Of the differentially expressed, 7 encoded genes associated with pathogen resistance. Taken together, our results suggest that gene expression patterns are different between a space flight-induced rice mutant and its on-ground control, and the differential expression of resistance genes may be a potential mechanism that modulates the resistance of 972-4 to rice blast. Our results also suggest

  4. Functional Analysis of Jasmonates in Rice through Mutant Approaches

    Rohit Dhakarey

    2016-03-01

    Full Text Available Jasmonic acid, one of the major plant hormones, is, unlike other hormones, a lipid-derived compound that is synthesized from the fatty acid linolenic acid. It has been studied intensively in many plant species including Arabidopsis thaliana, in which most of the enzymes participating in its biosynthesis were characterized. In the past 15 years, mutants and transgenic plants affected in the jasmonate pathway became available in rice and facilitate studies on the functions of this hormone in an important crop. Those functions are partially conserved compared to other plant species, and include roles in fertility, response to mechanical wounding and defense against herbivores. However, new and surprising functions have also been uncovered by mutant approaches, such as a close link between light perception and the jasmonate pathway. This was not only useful to show a phenomenon that is unique to rice but also helped to establish this role in plant species where such links are less obvious. This review aims to provide an overview of currently available rice mutants and transgenic plants in the jasmonate pathway and highlights some selected roles of jasmonate in this species, such as photomorphogenesis, and abiotic and biotic stress.

  5. Functional Analysis of Jasmonates in Rice through Mutant Approaches

    Dhakarey, Rohit; Kodackattumannil Peethambaran, Preshobha; Riemann, Michael

    2016-01-01

    Jasmonic acid, one of the major plant hormones, is, unlike other hormones, a lipid-derived compound that is synthesized from the fatty acid linolenic acid. It has been studied intensively in many plant species including Arabidopsis thaliana, in which most of the enzymes participating in its biosynthesis were characterized. In the past 15 years, mutants and transgenic plants affected in the jasmonate pathway became available in rice and facilitate studies on the functions of this hormone in an important crop. Those functions are partially conserved compared to other plant species, and include roles in fertility, response to mechanical wounding and defense against herbivores. However, new and surprising functions have also been uncovered by mutant approaches, such as a close link between light perception and the jasmonate pathway. This was not only useful to show a phenomenon that is unique to rice but also helped to establish this role in plant species where such links are less obvious. This review aims to provide an overview of currently available rice mutants and transgenic plants in the jasmonate pathway and highlights some selected roles of jasmonate in this species, such as photomorphogenesis, and abiotic and biotic stress. PMID:27135235

  6. Research tool uses of rice mutants for increasing crop productivity

    Induced mutants are being used in a three-phase programme to develop higher yielding models of the rice plant. Phase 1 is to use induced mutant genes, together with existing genes, to quickly develop near-isogenic comparisons. Phase 2 is to use these near-isogenics to test agronomical and physiological hypotheses about the bases for increased yield. Phase 3 is to use information developed from phase 2 to design more productive models of the rice plant for the future. Completed phase 1 and 2 studies show the following: Semidwarf plant height (90cm) increases grain yield about 15% over the tall height (120cm) in California's high yield environment. An induced mutant semidwarfing gene, sd1, does not reduce seedling vigour in water-sown rice. Semidwarfism has a beneficial effect in minimizing cold-induced sterility in warm water-cool night air situations. Doubledwarf recombinants from crosses between non-allelic semidwarfs generally are too short (80cm) for present cultural practices. Early maturing lines are higher yielding than late lines in cool environments, and yield as much as the late varieties even in warm environments. Studies on source/sink relationships and carbohydrate partitioning suggest that sink size (panicle size) is limiting rice yield in California. Therefore, genotypes are being developed with increased numbers of kernels/panicle, and/or larger kernel size. Thus, phase 1 and 2 results to date indicate that critical elements of phase-3-developed lines must include semidwarfism and early maturity. It is believed that further additions to the high yield model will include larger sink size, either through larger kernels or more kernels/panicle, or a combination of these two yield components. (author)

  7. An early maturing rice mutant released as a variety

    In the content of food grain production deficiency (about 1.0-1.5 million tons of rice per year according to the Bangladesh Bureau of Statistics, 1998) an induced mutation programme was undertaken in 1985. One moderate early maturing and high yielding rice mutant line (BINA6-84-4-115) has been developed by irradiating F2 seeds of the cross 'BR4' x 'Iratom 38'. Three treatments viz., 250, 300 and 350 Gy were given to the F2 seeds. Finally, this line was selected in M6 generation for advanced yield trial. The line was evaluated in comparative trials with another mutant line BINA6-84-4-163. These two mutant lines had been selected earlier from 300 Gy originated lines. The two check varieties, 'BR 11' and 'BR 22' were also included in the trial, which was conducted in two consecutive T. aman seasons (July to December) during 1994 and 1995 at five locations in Bangladesh. From the results, it was evident that the mutant BINA6-84-4-115 did not differ much with the other mutant lines or check varieties in respect to plant height, number of effective tillers and panicle length but it was 10-18 days earlier than the other 3 entries. It produced a similar yield as the check BR 11 in 1994 and a higher yield than the check BR 11 and BR 22 in 1995. This mutant line gave the highest yield per day among all the entries. In addition to this, the grains are long, fine and possess a high L/B ratio, which are of high commercial value. This line has been released by the National Seed Board of Bangladesh in 1998 as a commercial variety under the name 'BINADHAN-4' for cultivation throughout Bangladesh

  8. Selection for blast-resistant mutants in irradiated rice populations

    A newly released rice variety, Tongil, has many desirable agronomic characters and a particularly high resistance to blast disease. However, it may become susceptible in the future, since a resistant variety released for field planting often encounters the creation of new races of blast fungus. This study was undertaken to identify potential blast-resistant mutants from the population of the irradiated variety, Tongil, by inoculating these materials with induced mutant races of blast fungus which are likely to occur in the future. Blast conidia were irradiated with X-rays and the virulent mutants were identified according to their ability to infect Tongil. Seven blast-resistant mutant lines from the Pungkwang variety, selected through the uplands blast nursery test, were likewise outstanding in resistance in the field compared with the parent. Ten resistant lines from the variety Tongil, identified by artificial inoculation with the mutant race IA-67, were also selected. The results in the study of resistance inheritance showed that blast resistance was conditioned by a single dominant gene and the Tongil variety has three or more resistant genes. (author)

  9. Understanding the Molecular Mechanisms of Disease Resistance Using Rice Mutants

    The Pi-ta gene in rice has been used to prevent the rice blast disease worldwide for several decades. In the US, Pi-ta was introgressed from a landrace indica variety, Tetep, into several tropical japonica cultivars including Katy. Pi-ta is predicted to encode a cytoplasmic receptor that directly binds to the elicitor produced by the pathogen avirulence gene AVR-Pita for initiating resistance. Katy, expressing resistance conditioned by Pi-ta, Pi-ta2, and Pi-ks to the races of M. oryzae, IB1, IB45, IB49, IB54, IC17, IH1, IE1, and IG1, was treated with mutagens, fast neutrons and ethyl methyl sulfate (EMS). Six mutants with enhanced resistance or susceptibility were identified by screening M2 seedlings derived from 15,000 M1 plants. Among them, M562, induced by EMS, is a lesion mimic mutant (named as LMM1) that produces spontaneous hypersensitive cell death. This rapid cell death was quickly induced using detached leaves at and near the site of inoculation by the virulent race IE1k and more slowly induced when inoculated with the avirulent isolate IB49. Similar hypersensitive cell death was observed after detached leaves were inoculated with the fungus Rhizoctonia solani, the causal agent of rice sheath blight disease. Hypersensitive cell death is known to be a form of the defense response. Thus, we suggest that LMM1 has enhanced resistance to both rice blast and sheath blight pathogens. Although the Pi-ta gene in rice provides resistance to the races, IB1, IB45, IB49, IC17, IH1, IE1, IB54, and IG1, the mutant M2354 was observed to be susceptible to all races except IB54 although there was no change in the Pi-ta DNA sequence. Expression of Pi-ta in M2354 was also similar to that of the parent examined by qRT-PCR. Thus, mutations in M2354 likely occurred at a new locus named as Ptr(t). Another four lines were determined to be near isogenic lines at a 9 megabase genomic region spanning the Pi-ta locus of Katy. Progress on characterizing these six genetic stocks is

  10. Flavonoid accumulation patterns of transparent testa mutants of arabidopsis

    Peer, W. A.; Brown, D. E.; Tague, B. W.; Muday, G. K.; Taiz, L.; Murphy, A. S.

    2001-01-01

    Flavonoids have been implicated in the regulation of auxin movements in Arabidopsis. To understand when and where flavonoids may be acting to control auxin movement, the flavonoid accumulation pattern was examined in young seedlings and mature tissues of wild-type Arabidopsis. Using a variety of biochemical and visualization techniques, flavonoid accumulation in mature plants was localized in cauline leaves, pollen, stigmata, and floral primordia, and in the stems of young, actively growing inflorescences. In young Landsberg erecta seedlings, aglycone flavonols accumulated developmentally in three regions, the cotyledonary node, the hypocotyl-root transition zone, and the root tip. Aglycone flavonols accumulated at the hypocotyl-root transition zone in a developmental and tissue-specific manner with kaempferol in the epidermis and quercetin in the cortex. Quercetin localized subcellularly in the nuclear region, plasma membrane, and endomembrane system, whereas kaempferol localized in the nuclear region and plasma membrane. The flavonoid accumulation pattern was also examined in transparent testa mutants blocked at different steps in the flavonoid biosynthesis pathway. The transparent testa mutants were shown to have precursor accumulation patterns similar to those of end product flavonoids in wild-type Landsberg erecta, suggesting that synthesis and end product accumulation occur in the same cells.

  11. Agronomic traits and RAPD analysis of two mutants derived from rice somatic cell culturing

    2002-01-01

    Genetic variation, including agronomic trait variation, often occurs in somatic cell culturing. In this study, we compared the main agronomic traits of two rice mutants, M3 and M14, which were derived from Shenxiangjing 5 somatic cell culturing. Significant differences were found between the two mutants and the wild rice Shenxiangjing 5 (Table 1). Results were as follows:

  12. The induced SDI mutant and other useful mutant genes in modern rice varieties

    Induced mutation was accelerated in the USA with the release in California in 1976 of Calrose 76, the nation's first semidwarf table rice variety. Success was due not only to induction of mutants but also to their evaluation and integration into cross-breeding programs. Thus the evaluation of Calrose 76 showed that its sdl gene was allelic to sdl in the indica Green Revolution varieties DGWG, TN(1) and IR8, and that semidwarfism conferred a yield advantage of 14% over the 6mt/ha yield level of the tall japonicas. Immediate integration of the Calrose 76 source of semidwarfism into cross-breeding has resulted in 25 semidwarf varieties that trace their ancestral source of semidwarfism to Calrose 76: 13 in California, 10 in Australia, and 2 in Egypt. Calrose 76 ancestry also appears in the pedigrees of numerous additional California cultivars derived from crossing the Calrose 76 source with the IR8 source of semidwarfism. In the late 1990s 12 semidwarf mutants were induced in tall tropical japonica varieties at the Dale Bumpers National Rice Research Center in Arkansas. The semidwarfing gene in each of these 12 germplasms was found to be nonallelic to sdl. Although selected for productivity, none of the 12 consistently showed yield increases typical of sd1 sources. The sdl source, whether from induced mutation or from the indica source, is truly associated with enhanced productivity. Other induced mutants were found for early flowering, low phytic acid, giant embryo, and marker genes such as gold leaf and extreme dwarfism. The early flowering mutants were recovered in temperate japonicas, in tropical japonicas, and most recently in indicas. The early flowering indica mutants are quite interesting since they provide high yielding or blast disease-resistant indica germplasm which will mature in the USA. (author)

  13. The Induced sd1 Mutant and Other Useful Mutant Genes in Modern Rice Varieties

    Induced mutation was accelerated in the USA with the release in California in 1976 of Calrose 76, the nation's first semidwarf table rice variety. Success was due not only to induction of mutants but also to their evaluation and integration into cross-breeding programmes. Thus the evaluation of Calrose 76 showed that its sd1 gene was allelic to sd1 in the indica Green Revolution varieties DGWG, TN(1) and IR8, and that semidwarfism conferred a yield advantage of 14% over the 6mt/ha yield level of the tall japonicas. Immediate integration of the Calrose 76 source of semidwarfism into cross-breeding has resulted in 25 semidwarf varieties that trace their ancestral source of semidwarfism to Calrose 76: 13 in California, 10 in Australia, and 2 in Egypt. Calrose 76 ancestry also appears in the pedigrees of numerous additional California cultivars derived from crossing the Calrose 76 source with the IR8 source of semidwarfism. In the late 1990s 12 semidwarf mutants were induced in tall tropical japonica varieties at the Dale Bumpers National Rice Research Center in Arkansas. The semidwarfing gene in each of these 12 germplasms was found to be nonallelic to sd1. Although selected for productivity, none of the 12 consistently showed yield increases typical of sd1 sources. The sd1 source, whether from induced mutation or from the indica source, is truly associated with enhanced productivity. Other induced mutants were found for early flowering, low phytic acid, giant embryo, and marker genes such as gold leaf and extreme dwarfism. The early flowering mutants were recovered in temperate japonicas, in tropical japonicas, and most recently in indicas. The early flowering indica mutants are quite interesting since they provide high-yielding or blast disease-resistant indica germplasm which will mature in the USA. (author)

  14. Ascorbate-Glutathione Cycle Alteration in Cadmium Sensitive Rice Mutant cadB-1

    SHEN Guo-ming; ZHU Cheng; DU Qi-zhen; SHANGGUAN Li-na

    2012-01-01

    A rice cadmium (Cd) sensitive mutant cadB-1 was obtained using Agrobacterium tumefaciens mediated system.After exposure of cadB-1 and wild type (WT) rice seedlings to a range of Cd concentrations for 10 d,Cd accumulated to higher levels in roots,stems and leaves of both cadB-1 and WT with increasing external Cd concentrations,and the inhibition of seedling growth in cadB-1 was more serious than in WT.Hydrogen peroxide accumulation was higher in leaves and roots of cadB-1.The ratios of reduced glutathione (GSH)/oxidized glutathione (GSSG),ascorbate (ASC)/dehydroascorbate (DHA) and reduced nicotinamide adenine dinucleotide phosphate (NADPH)/oxidized nicotinamide adenine dinucleotide phosphate (NADP+) were lower in cadB-1 than in WT both in leaves and roots under high Cd levels.The activities of ascorbate peroxidase (APX),glutathione peroxidase (GR),dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) were also lower in cadB-1 than in WT both in leaves and roots under the treatment of high levels of Cd.Our results suggest that under Cd stress,the ASC-GSH cycle was more seriously inhibited in cadB-1 than in WT,indicating that the mutant cadB-1 is less able to scavenge reactive oxygen species and sensitive to Cd.

  15. Effects of Aluminium Sulfate on Cadmium Accumulation in Rice

    Full text: Cadmium accumulation in Pathum Thani 1 and Suphan Buri 60 rice cultivars was investigated upon treatment with aluminium sulfate as a precipitant. Rice was grown hydroponically in a medium containing 4 ppm cadmium nitrate with or without 4 ppm aluminium sulfate. Root, stem with leaves and grain samples were collected and analyzed for cadmium content using atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy. Without the addition of aluminium sulfate, Pathum Thani 1 and Suphan Buri 60 accumulated 24.71∫ 3.14 ppm and 34.43 ∫ 4.51 ppm (dry weight of whole plant) of cadmium, respectively. With aluminium sulfate, cadmium accumulation increased to 40.66 ∫ 2.47 ppm and 62.94 ∫ 10.69 ppm, respectively. The addition of aluminium sulfate to the planting medium did not reduce cadmium accumulation but caused the rice to accumulate more cadmium especially in the shoots and grains. This observation might serve as the basis for future research on the management of agricultural areas that are contaminated with cadmium and aluminium

  16. Cadmium transport and tolerance in rice: perspectives for reducing grain cadmium accumulation

    Uraguchi, Shimpei; Fujiwara, Toru

    2012-01-01

    Cadmium (Cd) is a toxic heavy metal which harms human health. In Japan, a major source of human Cd-intake is rice grains and contamination of paddy soils by Cd and accumulation of Cd in rice grains are the serious agricultural issues. There also exist Cd contamination of rice and its toxicity in several populations in countries including China and Thailand. Understanding the Cd transport mechanisms in rice can be a basis for regulating rice Cd transport and accumulation by molecular engineeri...

  17. Biochar amendment reduced methylmercury accumulation in rice plants.

    Shu, Rui; Wang, Yongjie; Zhong, Huan

    2016-08-01

    There is growing concern about methylmercury (MeHg) accumulation in rice grains and thus enhanced dietary exposure to MeHg in Asian countries. Here, we explored the possibility of reducing grain MeHg levels by biochar amendment, and the underlying mechanisms. Pot (i.e., rice cultivation in biochar amended soils) and batch experiments (i.e., incubation of amended soils under laboratory conditions) were carried out, to investigate MeHg dynamics (i.e., MeHg production, partitioning and phytoavailability in paddy soils, and MeHg uptake by rice) under biochar amendment (1-4% of soil mass). We demonstrate for the first time that biochar amendment could evidently reduce grain MeHg levels (49-92%). The declines could be attributed to the combined effects of: (1) increased soil MeHg concentrations, probably explained by the release of sulfate from biochar and thus enhanced microbial production of MeHg (e.g., by sulfate-reducing bacteria), (2) MeHg immobilization in soils, facilitated by the large surface areas and high organosulfur content of biochar, and (3) biodilution of MeHg in rice grains, due to the increased grain biomass under biochar amendment (35-79%). These observations together with mechanistic explanations improve understanding of MeHg dynamics in soil-rice systems, and support the possibility of reducing MeHg phytoaccumulation under biochar amendment. PMID:27045620

  18. PHENOTYPIC ANALYSIS OF OsTPKb LOSS OF FUNCTION MUTANT RICE LINES

    Isayenkov S. V.

    2015-08-01

    Full Text Available The results of screen and analysis of two OsTPKb rice mutant lines were described. The phenotypes and growth rate level of homozygous mutant plants of both rice lines were estimated. The electron microscopy of aleurone layer from forming seeds was performed. The OsTPKb mutant plants demonstrate lower growth rate in comparison with wild type plants. The loss of function OsTPKb mutations invariably led to (semisterile rice plants. The functional disruption of OsTPKb channel has negative impact on plant growth and development. It might completely change the cell morphology of aleurone layer.

  19. Arsenic accumulation in rice grains as affected by cultivars and water management practices

    Arsenic (As) accumulation in rice grains is a threat to human health and marketability of rice products. The accumulation has been linked to the elevated As in soil resulting from pesticide application and/or irrigation water quality. In an effort to minimize As uptake by rice grain and occurrence o...

  20. Modified accumulation of selected heavy metals in Bt transgenic rice

    WANG Haiyan; HUANG Jianzhong; YE Qingfu; WU Dianxing; CHEN Ziyuan

    2009-01-01

    Safety assessment of genetically modified crops generally does not take into account the potential hazard of altered patterns of heavy metal accumulation in plants.A pot experiment was conducted under greenhouse conditions to evaluate the impact of heavy metal amendments on the accumulation of Cd,Cu,Pb and Zn in a Bt transgenic rice Ke-Ming-Dao (KMD) and its wild-type Xiushui 11 (Xs11).In control soils,significant difference was only found in contents of Cu (p < 0.01) and Pb (p < 0.05) in straw between KMD and Xs11.At three levels of Cd amendments (5,10,and 20 mg/kg),the Cd contents in grain and straw of KMD were significantly higher than those of Xs11,and all grain Cd contents were significantly higher than the international criteria (0.2-0.4 mg/kg) as specified by the Codex Alimentarius Commission (CAC).These results implied that it may be unsafe for growing Bt transgenic rice in heavily Cd-polluted areas.No significant difference in Zn was found between the two varieties with the exception of roots at Zn amendment level of 600 mg/kg,while Pb contents in KMD were much higher in the straw at the lead amendment level of 1000 mg/kg and in the root at 250 mg Pb/kg.Data on the heavy metal accumulation patterns for the genetically modified rice may be used for the selection of growing areas as well as for plant residue management for Bt rice.

  1. Revealing of complex system of starch synthetic metabolism in higher plants using rice mutants

    In this presentation, the concept and perspective of molecular mutation breeding of starch biosynthesis are discussed. Amylopectin, a major component of starch, has a distinct highly-ordered structure referred to as 'tamdem-cluster structure'. The starch synthesis system has developed during the process of evolution of plants, and key enzymes involved in the construction of amylopectin tamdem-cluster structure have differentiated into multiple isozymes with specific functions. Detailed analyses of changes in the structure of amylopectin and the physicochemical properties of starch granules in rice endosperm induced by lesion of each isoform of starch branching enzyme, starch synthase, starch debranching enzymes and others have established that the individual mutants exhibit distinct characteristics in terms of the starch structure and properties. These patterns of changes reflected by the specific functions of enzymes in starch biosynthesis enable us to expect to what extent and how the structure and properties of starch can be engineered. In fact, numerous rice mutant lines could be used in the industrial purpose in the future by the production of novel starches in endosperm. Transcriptome analysis established that changes in the transcript levels of starch synthesizing enzyme genes in rice endosperm are largely divided into two patterns. One group of genes are highly expressed in the very early stage of the endosperm development prior to the onset of the rapid starch production whereas the other group genes are greatly expressed in accord with the start of a great amount of starch accumulation in the endosperm. These results strongly suggest that the initiation process of starch biosynthesis and the accumulationen process of increases in number of starch molecules and starch granule are regulated by different mechanisms with varied sets of isozymes. Our recent studies showed that plastidial phosphorylase plays a crucial role in the initial stage of starch

  2. Differential analysis in Proteome of Space Induced Rice and Soybean Mutants

    Wang, W.; Lu, B.; Gu, D.; Han, S.; Gao, Y.; Sun, Y.

    To investigate the change trends of proteome induced in space environment we chose 3 Rice mutants 2 Soybean mutants and the seeds which were selected as high yields high tillering rice blast resistance soybean insect pest resistance and wider leaf shape individually after abroad Recoverable Satellite JB-1 for 15 days in 1996 and their corresponding controls Two-dimensional gel electrophoresis 2-D with Coomassie Brilliant Blue staining and PDQuest TM software analysis found that In 6 rice samples 329 pm 35 protein spots were detected in controls whereas 298 pm 37 protein spots detected in mutants representing a 9 decrease 69 pm 27 protein spots were lost in mutants while 37 pm 14 protein spots appeared additionally showing 11 protein spots were lost in mutants 58 protein spots were significantly regulated in mutants with 16 pm 7 up- and 42 pm 18 down-regulated which occupied 5 and 14 of the total average mutants spots separately In 3 soybean leaf samples 263 pm 12 protein spots were detected in controls whereas 255 pm 20 protein spots detected in mutants representing a 3 decrease 49 pm 10 protein spots were lost in mutants while 36 pm 16 protein spots appeared additionally showing 5 protein spots lost in mutants 51 protein spots were significantly regulated in mutants with 25 pm 7 up- and 26 pm 15 down-regulated which occupied 9 8 and 10 2 of the total average mutants spots separately In 3 soybean seed samples 208 pm 41 protein spots were

  3. Evaluation of some mutant lines of rice induced by gamma radiation treatment 1. mean performance of rice mutants in M4 generation

    Grains of eight rice mutants; SC 1, SC 6, RTY 1, RTY 3, HY 14, HYI 17, EH 4 and HYPI 22 were secured from Botany Department Faculty of Agriculture Cairo university. The procedures and the methodology for induction these mutants as well as the original mean performance of such mutants are presented else where; Sabbour, (1989) and Sabbour etal. (2002). Grains were sown (M4 generation) at the experimental farm in Itai EI-Baroud Agricultural Research Station Behaira Governorate Agricultural Research Center (ARC) in the summer season (2007). The mean performance of such mutants was studied during M4 generation. The most exciting results were as follows: the selected line SC 1 showed in M4 generation superior agronomic and yield traits. Sc 1 mutant line is not bred truly and it need more generations to reach stability. SC 6 in M4 generation showed considerable number of individuals scored low mean values toward the negative direction and lowering the overall trait mean performance. The rice lines RTY 1 and RTY 3 proved that, the average number of fertile tillers per plant of the selected lines maintained previously recorded mean values of M3 generation in M4. The traits showed significant differences among their progeny that recorded high CV% values as compared with those showed no significant differences. The rice lines HY 14 and HYI 17 showed a true breeding signs and no more breeding generations are required. Rice lines EH 4, showed a considerable reduction in number of days elapsed from date of cultivation till harvest. As, this mutant maintained 86.58 days till heading. Rice mutant line HYPI 22 did not bred truly for the original selected traits (high yield and high protein content) and it still need more generations of selection to reach considerable stability

  4. Assessment of gamma ray induced advance generation mutants of short grain aromatic non-Basmati rice

    Agronomic worth of 18 gamma ray induced mutants in M4 generation was assessed along with their two mother genotypes (Pigmented mutant and IET 13541), having the genetic background of Gobindabhog, a short grain aromatic non-Basmati rice cultivar, popularly grown in southern parts of West Bengal. The mutants showed considerable amount of genetic variability for different agronomic characters. Majority of the mutants had combination of both positive and negative forms of important yield contributing characters. Performance of three mutants (G1m3, G2m4 and G2m9) indicated considerable improvement in grain yield over their respective control. The increased grain yield per plant in above mutants is primarily due to increase in panicle number per plant, spikelet number per panicle, grain number per panicle and test weight. These high yielding multilocational mutants need further testing in multilocation trials for evaluation of their potential for direct release as varieties of short grain aromatic rice. The other mutants may be used in cross breeding programmes of aromatic rice for utilization of agronomically useful mutant characters viz., earlier flowering, short plant stature, erect flag leaf, higher grain number, more test weight and others. The apparent changes for different characters in individual mutant may not be due to genetic changes in all the affected characters. The possible role of pleiotropic effects of mutant gene cannot be ruled out. (author)

  5. Different responses of low grain-Cd-accumulating and high grain-Cd-accumulating rice cultivars to Cd stress.

    Wang, Feijuan; Wang, Min; Liu, Zhouping; Shi, Yan; Han, Tiqian; Ye, Yaoyao; Gong, Ning; Sun, Junwei; Zhu, Cheng

    2015-11-01

    Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars. PMID:26318143

  6. Leaf senescence and protective enzyme activities of a xantha mutant rice (Oryza sativa L.)

    The relationship between leaf senescence and the activities of protective enzymes was studied through comparion of a xanthan rice mutant HuangyuB with its wild type parent Longtefu B. During 5-25 days after flowering, compared to the wild type the decreases in the contents of chlorophyll and protein, and increases in the content of malondialdehyde (MDA) were significantly slower in the mutant. The activities of three protective enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), were relatively stable in the mutant, indicating the stronger ability in removing free radicals and active oxygen in HuangyuB than the wild type. The criterion of rice senescence was also discussed. (authors)

  7. Understanding the molecular mechanisms of rice blast resistance using rice mutants

    Induced mutation can be useful for studying resistance gene controlled plant immunity. Resulting knowledge should benefit the development of strategies for crop protection. The Pi-ta gene in rice has been effectively deployed for preventing rice blast disease-the most devastating disease of rice worldwide. Pi-ta was introgressed into diverse cultivars in the US and Japan from landrace indica varieties, Tetep and Taducan, respectively. Pi-ta was predicted to be a cytoplasmic receptor that directly binds to the elicitor produced by the pathogen avirulence gene AVR-Pita for initiating resistance. Alanine located at position 918 of the Pi-ta protein in the region predicted to be involved in ligand binding has been shown to determine the binding specificity. Here I report the identification of a second gene, Ptr(t), required by Pi-ta for resistance. Katy, a tropical japonica cultivar from the US, expressing resistance conditioned by Pi-ta and Pi-ks to the common races of M. oryzae, IB1, IB45, IB49, IB54, IC17, IH1, IE1, and IG1 was treated with fast neutrons. Five susceptible M2 mutants were identified by screening seedlings derived from 10,000 M1 plants. Among them a stable mutant M2354 was found susceptible to IB1, IB45, IB49, IC17, IH1, IE1, and IG1 conditioned by Pi-ta and resistant to IB54 conditioned by Pi-ks. The DNA sequences of the Pi-ta gene in M2354 was found unchanged based on PCR-sequencing. Expression of Pi-ta in M2354 was also found identical to that of the mother parent examined by qRT-PCR and real time RT-PCR. Thus, mutations in M2354 likely occurred at a new locus specific to Pi-ta-mediated resistance. Genetic analysis and genotyping the Pi-taptr(t), Pi-taPtr(t), pitaptr( t) homozygotes revealed that Pi-ta and Ptr(t) co-segregate and are located within a 9 megabase genomic region on chromosome 12. These findings provide a starting point to isolate Ptr(t) and dissect the Pi-ta mediated signaling pathways leading to resistance. (author)

  8. Variation in eating quality of early maturing mutant lines of rice induced by space technique

    Variations in eating quality of 9 mutant lines derived from single season indica rice variety Jingxian 89 by the treatment of space technique were investigated. The result indicated that the exterior quality of some mutant lines including grain shape and endosperm appearance changed obviously. AAC was induced into three categories: low, moderate and high AAC. Alkali spreading value and starch viscosity of most mutant lines were significantly worse than those of the original parent. However, the gel consistence of mutant lines was similar or improved obviously. Except SP501, major agronomic traits of mutant lines were worse than those of the control, but one thousand grains weight increased obviously

  9. Using iron fertilizer to control Cd accumulation in rice plants: A new promising technology

    2008-01-01

    Effects of two kinds of iron fertilizer, FeSO4 and EDTA·Na2Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA·Na2Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA·Na2Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentra- tion in cereal crop foods in State standard. However, soil application of FeSO4 or foliar application of FeSO4 or EDTA·Na2Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentra- tion of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA·Na2Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.

  10. Accumulation of total mercury and methylmercury in rice plants collected from different mining areas in China

    A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk and leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- Highlights: • Distribution patterns indicated different pathways of IHg and MeHg accumulation. • Soil is an important source for both THg and MeHg to rice plants. • Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- The distribution patterns indicate different pathways of IHg and MeHg accumulation in rice plants

  11. Screening and breeding of rice-blast resistant mutant variety

    A rice variety, Shengxianggeng No.4 bred with irradiation of soft X-rays was characterized by short stem, high yield, good quality with special scent and high resistance to rice blast. This new variety showed a high resistance to 87 tested pathogen strains

  12. Changes in Chlorophyll Fluorescence of Rice Mutants Induced by High Hydrostatic Pressure

    BAI; Cheng-ke; LI; Gui-shuang; PENG; Chang-lian; DUAN; Jun

    2003-01-01

    Three mutants of rice (Oryza sativa L. ), Mutant 1, Mutant 2and Mutant 3, which were selected by high hydrostatic pressure (75 MPa), and their parent Yuexiangzhan were used to study the changes in chlorophyll fluorescence during different growth stages. In all the three mutants, the function of PSⅡ was improved, Fy/Fm ratio of mutants increased compared to their parent at tillering and heading stage, and φPS Ⅱ also improved except for Mutant 2 at heading stage. Similar to their parent, the mutants exhibited slight photoinhibition at noon and almost complete recovery to initial levels of 6:00 after 18:00 at heading stage. At milking stage, the photoinhibition in the mutants was obvious, and recovered rapidly compared to the parent. Yields of individual plant and grain/straw ratio were also higher in three mutants than the parent. Results indicated that characteristics of chlorophyll fluorescence in leaves of mutants and their photoinhibition in the field had changed. It is suggested that high hydrostatic pressure induction could be applied as a new effective approach in high-yield rice breeding in the future.

  13. Study on selection and evaluation of japonica rice mutant E203 with superior grain quality

    Dry seeds of F0 come from the crossing of japonica rice Hainan 68 x Jia 52 were treated with 100 Gy of 60Co γ-rays, and the F1 were treated with 200 Gy of 60Co γ-rays. A japonica rice mutant with superior grain quality was selected in the following generation, and named as E203. It was demonstrated that the mutant had excellent milling and cooking quality as compared with its original parents and japonica rice variety Xiushui 11 with superior grain quality in Zhejiang province, better milling quality and almost the same cooking quality as compared with koshihikari--a famous japonica rice variety with superior quality introduced from Japan. It also had higher yield and stronger blast resistant ability. The above results show that it is possible and effective to improve grain quality of japonica rice by means of irradiation E203 with the improved comprehensive agronomic characters might be directly applied to the rice production, and might be used as a good gene resource of rice for improving grain quality in japonica rice breeding

  14. Comparison on cellular mechanisms of iron and cadmium accumulation in rice: prospects for cultivating Fe-rich but Cd-free rice.

    Gao, Lei; Chang, Jiadong; Chen, Ruijie; Li, Hubo; Lu, Hongfei; Tao, Longxing; Xiong, Jie

    2016-12-01

    Iron (Fe) is essential for rice growth and humans consuming as their staple food but is often deficient because of insoluble Fe(III) in soil for rice growth and limited assimilation for human bodies, while cadmium (Cd) is non-essential and toxic for rice growth and humans if accumulating at high levels. Over-accumulated Cd can cause damage to human bodies. Selecting and breeding Fe-rich but Cd-free rice cultivars are ambitious, challenging and meaningful tasks for researchers. Although evidences show that the mechanisms of Fe/Cd uptake and accumulation in rice are common to some extent as a result of similar entry routes within rice, an increasing number of researchers have discovered distinct mechanisms between Fe/Cd uptake and accumulation in rice. This comprehensive review systematically elaborates and compares cellular mechanisms of Fe/Cd uptake and accumulation in rice, respectively. Mechanisms for maintaining Fe homeostasis and Cd detoxicification are also elucidated. Then, effects of different fertilizer management on Fe/Cd accumulation in rice are discussed. Finally, this review enumerates various approaches for reducing grain Cd accumulation and enhancing Fe content in rice. In summary, understanding of discrepant cellular mechanisms of Fe/Cd accumulation in rice provides guidance for cultivating Fe-fortified rice and has paved the way to develop rice that are tolerant to Cd stress, aiming at breeding Fe-rich but Cd-free rice. PMID:27502932

  15. Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

    The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

  16. Characterization and Genetic Analysis of a Novel Mutant mst of Rice Defective in Flower Development

    LI Yun; XU Pei-zhou; ZHANG Hong-yu; FU Shao-hong; YANG Jin; ZHANG Ru-quan; WU Xian-jun

    2009-01-01

    A spontaneous mutant with multiple stigmas (mst) was found in an indica rice line 466. The mst mutant exhibits normal at the vegetative development stage and produces normal inflorescence structures. The difference between the mutant and the wild type was observed when the stamen primordium began to develop. In the mst florets, palea and lemma opened, lodicules were homeotically transformed into palea/lemma-like structures, and stamens were homeotically transformed into carpel-like structures. It looked like multiple stigmas being full of the whole floret. The phenotypic changes of mst were very similar to that of B-like mutant spw1. Compared with other mutants with pistillate morphologies, the severe mst florets showed that the inner three floral organs were completely changed into palea/lemma-like structures. Moreover, the mutant was female sterile. Occasionally, with the changing environment, one or two stamens were fertile. Genetic analysis indicated that the mutant traits were controlled by a single recessive gene.

  17. Screening of resistant mutant induced by γ-rays irradiation to rice blast

    Rice seeds were irradiated with 60Co γ-rays to induce mutants, which resistant to rice blast were screened in subculture medium and differentiation medium under mix toxin from dominant strains of pyricularia grisea in Heilongjiang. The results indicated that the inductivity of callus of mature rice embryo by irradiation was very low and the browning rate of callus was very high. However, the resistance rate of resistant regenerating plants was obviously higher, which indicated the resistant breeding by irradiation and biotechnology had a great potential and a better prospect. (authors)

  18. Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

    Carey, Anne-Marie; Scheckel, Kirk G.; Lombi, Enzo; Newville, Matt; Choi, Yongseong; Norton, Gareth J.; Price, Adam H.; Meharg, Andrew A. (EPA); (U. South Australia); (Aberdeen); (UC)

    2012-09-05

    Efficient Se biofortification programs require a thorough understanding of the accumulation and distribution of Se species within the rice grain. Therefore, the translocation of Se species to the filling grain and their spatial unloading were investigated. Se species were supplied via cut flag leaves of intact plants and excised panicle stems subjected to a {+-} stem-girdling treatment during grain fill. Total Se concentrations in the flag leaves and grain were quantified by inductively coupled plasma mass spectrometry. Spatial accumulation was investigated using synchrotron X-ray fluorescence microtomography. Selenomethionine (SeMet) and selenomethylcysteine (SeMeSeCys) were transported to the grain more efficiently than selenite and selenate. SeMet and SeMeSeCys were translocated exclusively via the phloem, while inorganic Se was transported via both the phloem and xylem. For SeMet- and SeMeSeCys-fed grain, Se dispersed throughout the external grain layers and into the endosperm and, for SeMeSeCys, into the embryo. Selenite was retained at the point of grain entry. These results demonstrate that the organic Se species SeMet and SeMeSeCys are rapidly loaded into the phloem and transported to the grain far more efficiently than inorganic species. Organic Se species are distributed more readily, and extensively, throughout the grain than selenite.

  19. Identification of altered metabolic pathways of γ-irradiated rice mutant via network-based transcriptome analysis.

    Hwang, Sun-Goo; Kim, Dong Sub; Hwang, Jung Eun; Park, Hyeon Mi; Jang, Cheol Seong

    2015-12-01

    In order to develop rice mutants for crop improvement, we applied γ-irradiation mutagenesis and selected a rice seed color mutant (MT) in the M14 targeting-induced local lesions in genome lines. This mutant exhibited differences in germination rate, plant height, and root length in seedlings compared to the wild-type plants. We found 1645 different expressed probes of MT by microarray hybridization. To identify the modified metabolic pathways, we conducted integrated genomic analysis such as weighted correlation network analysis with a module detection method of differentially expressed genes (DEGs) in MT on the basis of large-scale microarray transcriptional profiling. These modules are largely divided into three subnetworks and mainly exhibit overrepresented gene ontology functions such as oxidation-related function, ion-binding, and kinase activity (phosphorylation), and the expressional coherences of module genes mainly exhibited in vegetative and maturation stages. Through a metabolic pathway analysis, we detected the significant DEGs involved in the major carbohydrate metabolism (starch degradation), protein degradation (aspartate protease), and signaling in sugars and nutrients. Furthermore, the accumulation of amino acids (asparagine and glutamic acid), sucrose, and starch in MT were affected by gamma rays. Our results provide an effective approach for identification of metabolic pathways associated with useful agronomic traits in mutation breeding. PMID:26361777

  20. Studies on Aspergillus oryzae Mutants for the Production of Single Cell Proteins from Deoiled Rice Bran

    Ravinder, Rudravaram; Venkateshwar Rao, Linga; Ravindra, Pogaku

    2003-01-01

    Ethyl methyl sulphonate was used to induce point mutation in Aspergillus oryzae (MTCC 1846). Incubation with ethyl methyl sulphonate for 1 h resulted in 98 % killing of spores. By screening the survived colonies three hypermorphs were found (Shan1, Shan2 and Shan3). These three mutants along with the A. oryzae (MTCC 1846) were used for the production of single cell proteins. They grew profusely on deoiled rice bran and produced higher percentage of protein. Among the three mutants Shan2 ha...

  1. The Fd-GOGAT1 mutant gene lc7 confers resistance to Xanthomonas oryzae pv. Oryzae in rice.

    Chen, Honglin; Li, Chunrong; Liu, Liping; Zhao, Jiying; Cheng, Xuzhen; Jiang, Guanghuai; Zhai, Wenxue

    2016-01-01

    Disease resistance is an important goal of crop improvement. The molecular mechanism of resistance requires further study. Here, we report the identification of a rice leaf color mutant, lc7, which is defective in chlorophyll synthesis and photosynthesis but confers resistance to Xanthomonas oryzae pv. Oryzae (Xoo). Map-based cloning revealed that lc7 encodes a mutant ferredoxin-dependent glutamate synthase1 (Fd-GOGAT1). Fd-GOGAT1 has been proposed to have great potential for improving nitrogen-use efficiency, but its function in bacterial resistance has not been reported. The lc7 mutant accumulates excessive levels of ROS (reactive oxygen species) in the leaves, causing the leaf color to become yellow after the four-leaf stage. Compared to the wild type, lc7 mutants have a broad-spectrum high resistance to seven Xoo strains. Differentially expressed genes (DEGs) and qRT-PCR analysis indicate that many defense pathways that are involved in this broad-spectrum resistance are activated in the lc7 mutant. These results suggest that Fd-GOGAT1 plays an important role in broad-spectrum bacterial blight resistance, in addition to modulating nitrogen assimilation and chloroplast development. PMID:27211925

  2. Study on the induction and selection of rice mutant R917 for blast disease (Piricularia oryzae) resistance

    Rice F0 seeds were treated with 10 krad of 60Co γ-rays, and blast resistance mutant R917 was selected in the following generations. The blast resistance was tested by inoculating the mutant with 138 strains of Piricularia oryzae artificially from nine blast regions in Zhejiang Province, scale of blast resistance was only 0.89 and 1.0 in 1991 and 1992 respectively. The rice mutant R917 was resistant to 136 blast fungus strains. The rate of blast resistance for R917 was higher than that of its parents. The mutant is likely to be used in rice breeding for variety improvement

  3. Water Management Practices Affect Arsenic and Cadmium Accumulation in Rice Grains

    Liming Sun

    2014-01-01

    Full Text Available Cadmium (Cd and arsenic (As accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously.

  4. Genetic Analysis and Molecular Mapping of a Novel Chlorophyll-Deficit Mutant Gene in Rice

    HUANG Xiao-qun; WANG Ping-rong; ZHAO Hai-xin; DENG Xiao-jian

    2008-01-01

    A rice etiolation mutant 824ys featured with chlorophyll deficiency was identified from a normal green rice variety 824B.It showed whole green-yellow plant from the seedling stage,reduced number of tillers and longer growth duration.The contents of chlorophyll,chlorophyll a,chlorophyll b and net photosynthetic rate in leaves of the mutant obviously decreased,as well as the number of spikelets per panicle,seed setting rate and 1000-grain weight compared with its wild-type parent.Genetic analyses on F1 and F2 generetions of 824ys crossed with three normal green varieties showed that the chlorophyll-deficit mutant character was controlled by a pair of recessive nuclear gene.Genetic mapping of the mutant gene was conducted by using microsatellite markers and F2 mapping population of 495R/824ys,and the mutant gene of 824ys was mapped on the shon arm of rice chromosome 3.The genetic distances from the target gene to the markers RM218,RM282 and RM6959 were 25.6 cM,5.2 cM and 21.8 cM,respectively.It was considered to be a now chlorophyll-deficit mutant gene and tentatively named as chl11(t).

  5. Development of photoperiod insensitive mutant lines using gamma irradiation of traditional aromatic rice

    Traditional high quality rice varieties are very often photoperiod sensitive and thus have long growth duration. The aromatic rice varieties, Aromatic Tam Rice (ATR) grown in North Viet Nam, and Khaodowmali 105 (KDML 105) grown in Thailand, are representative of this kind. ATR has been grown in the Red River Delta of North Viet Nam for thousands of years. It is a strictly photoperiod sensitive variety, and has a long growth duration of more than 160 days, therefore, it can be grown only once a year. It has also other non-preferred characteristics, such as high plant type (>160 cm), small and short grains (19 g per 1000 grains), and low yield (60Co at the dosage of 60 Gy. Three novel mutant lines were selected at M4 and became bred-true at M6-7. The mutant characteristics included photoperiod insensitivity, shortened plant type (<100 cm), early maturity (90 - 100 d), and extra long and large grain type (35-65% increase of 1000 grains weight). Subsequently, the mutant lines all had higher yields (over 5.5 t/ha) than ATR, while their grain quality remained high. In addition, a mutant line with red pericarped grains was also isolated from the mutant population. Similar results had been obtained from the irradiated KDML105 progeny. Two photoperiod insensitive mutant lines were identified and have already been demonstrated in large scale trials in Soctrang Province

  6. Transcriptional profile of genes involved in ascorbate glutathione cycle in senescing leaves for an early senescence leaf (esl) rice mutant.

    Li, Zhaowei; Su, Da; Lei, Bingting; Wang, Fubiao; Geng, Wei; Pan, Gang; Cheng, Fangmin

    2015-03-15

    To clarify the complex relationship between ascorbate-glutathione (AsA-GSH) cycle and H2O2-induced leaf senescence, the genotype-dependent difference in some senescence-related physiological parameters and the transcript levels and the temporal patterns of genes involved in the AsA-GSH cycle during leaf senescence were investigated using two rice genotypes, namely, the early senescence leaf (esl) mutant and its wild type. Meanwhile, the triggering effect of exogenous H2O2 on the expression of OsAPX genes was examined using detached leaves. The results showed that the esl mutant had higher H2O2 level than its wild type at the initial stage of leaf senescence. At transcriptional level, the association of expression of various genes involved in the AsA-GSH cycle with leaf senescence was isoform dependent. For OsAPXs, the transcripts of two cytosolic OsAPX genes (OsAPX1 and OsAPX2), thylakoid-bound OsAPX8, chloroplastic OsAPX7 and peroxisomal OsAPX4 exhibited remarkable genotype-dependent variation in their expression levels and temporal patterns during leaf senescence, there were significantly increasing transcripts of OsAXP1 and OsAPX7, severely repressed transcripts of OsAPX4 and OsAPX8 for the esl rice at the initial leaf senescence. In contrast, the repressing transcript of OsAPX8 was highly sensitive to the increasing H2O2 level in the senescing rice leaves, while higher H2O2 concentration resulted in the enhancing transcripts of two cytosolic OsAPX genes, OsAPX7 transcript was greatly variable with different H2O2 concentrations and incubating duration, suggesting that the different OsAPXs isoforms played a complementary role in perceiving and scavenging H2O2 accumulation at various H2O2 concentrations during leaf senescence. Higher H2O2 level, increased AsA level, higher activities of APX and glutathione reductase (GR), and relatively stable GSH content during the entire sampling period in the leaves of esl mutant implied that a close interrelationship existed

  7. Agrobacterium mediated construction of rice mutant population with transposon

    2001-01-01

    Transposon tagging is a powerful tool for gene study, especially for genes among different plants, such as Arabidopsis, tobacco, and tomato, etc. This effective strategy for gene isolation has been applied to rice and progress has been made in recent years.

  8. Susceptibility of ''Yuanfengzao'' and other mutant rice varieties to herbicides

    Herbicides are used to control barngrass and other water grasses in rice fields. However, rice may suffer in some cases too. We developed a technique to evaluate rice for herbicide tolerance at seedling stage. The seedlings were grown in 15, 20, 50 cm plastic trays with 7 cm soil. Up to 2-leaf stage, seedlings were treated with 50, 100 and 500 ppm butachlor, and 250, 500 and 1000 ppm thiobencarb respectively, in the incubator (30/25 deg. C day/night, 12 h light and 3000 lux/d) up to 11 d. The herbicide solution was filled up to the pulvinus of the second leaf, with water treatment as a check. Light brown spots on the leaf were the most visible injury symptom and might be used as criterion of herbicide susceptibility in Indica rice at seedling stage. During treatment, the first leaf became yellow and was killed first, then the water soaked spots appeared on the second leaf and turned to light brown spots gradually. Afterwards, the light brown spots linked up with each other and the leaf became partially necrotic. On the third leaf light brown spots appeared also. Finally, the seedling was killed

  9. A Mitigation Approach to Alleviate Arsenic Accumulation in Rice through Balanced Fertilization

    S. M. Imamul Huq

    2011-01-01

    Full Text Available Pot experiments with boro and aman season rice on the same soils treated with arsenic contaminated irrigation water and using balanced fertilizer or not revealed that balance fertilization could be a strategy to mitigate arsenic accumulation in rice grain. The study also revealed that there is a carryover effect of As applied through irrigation in the boro season to the subsequent aman season rice. This carryover effect too, could be minimized with balanced fertilization.

  10. Agronomic and molecular evaluation of induced mutant rice (oryza sativa l.) lines in Egypt

    The present study was conducted at the farm of the Rice Research and Training Center, Sakha, Kafr El-Sheikh, Egypt, during 2000-2007 rice sowing seasons. Five rice varieties viz., Giza 171, Giza 175, Giza 176, Giza 181 and GZ 1368 were the most widely grown Japonica and Indica types in Egypt during the last period, possesses at that time many positive agronomic characteristics including wide adaptability, high yield potential, tolerance to stresses and good eating quality. But with the passage of time it has lost its vigor. In Rice Research Program, Egypt, dry seeds of the above mentioned varieties were treated with different doses of gamma rays (100, 200, 300, 400, and 500 Gy) for raising M1 generation. M1 plants were established by transplanting in the year 2000 season. One hundred independent lines have been advanced to M5 generation enabling evaluation of quantitative traits by replicated trials and promising lines were selected and tested in multi-location trials as M6, M7 and M8 generations. Morphological variations at vegetative and reproductive stages including plant type and various physiological characters were observed in the five populations. The mutant lines characteristics consisted of better resistance to lodging, blast disease, high yield potential, as well as early maturity. Results from yield trials and molecular assessments indicated that the mutants differed genetically from their parents. So, these mutants could be used as a donor parents in rice breeding program and some of them can be recommended as new rice varieties suitable for rice belt in Egypt. (author)

  11. Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

    To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha-1 versus 6.6 t ha-1. These mutants show lodging and shattering resistance. (Author)

  12. Diversity and Stability Study on Rice Mutants Induced in Space Environment

    Wei-Hong Lu; Xin-Zhu Wang; Qi Zheng; Shuang-Hong Guan; Ping Xin; Ye-Qing Sun

    2008-01-01

    To further study the characteristics of changes on the molecular level of rice mutants induced in space environment, we analyzed proteins in leaves and seeds of four rice mutants (two high-tillering and two low-tillering) in the 8th and 9th generations after a 15-day spaceflight, and compared with their ground controls by two-dimentional polyacrylamide gel electrophoresis and reverse phase liquid chromatography (RPLC). In addition, the albumin, globulin, prolamine, glutelin, and amylose of the mutant seeds were analyzed by RPLC and ultra-violet spectrometry. The results showed that the low-abundance proteins of leaves in the peak tillering stage are more likely to be induced compared with their corresponding controls. The albumin, globulin, and prolamine of the mutant seeds revealed changes when compared with their controls, and the characteristics of changes in different mutants were stably inherited in the 8th and 9th generations, suggesting that they can be used as biomarkers to identity the mutants induced by spaceflight. Moreover, two proteins (SSP9111 and SSP6302) were found to be expressed with high intensity (two-fold change) in different mutants, which were both correlated with photosystem according to mass spectrometry and database searching.

  13. Physicochemical properties and starch structure of a rice mutant with reduction of starch paste viscosity

    Variations in starch physicochemical properties and starch structure between the rice low-paste viscosity mutant RSV-1 and its original parent II-32B were investigated. The results indicated that the apparent amylose content (AAC), gel consistency (GC), alkali spreading value (ASV) of mutant RSV-1 were higher than the wild type. However, major parameters of starch paste viscosity in mutant RSV-1 starch, i. e. peak paste viscosity, hot paste viscosity, and cool paste viscosity were significantly lower than those of the original parent. Compared to the original parent, the mutant had a similar peak time, but less energy and longer time needed for gelatinization. The starch manifested C-type crystalline and starch granule in the endosperm were irregular with different diameters. The mutation of the starch structure might play a key role for the decrease of starch paste viscosity in the mutant RSV-1. (authors)

  14. Morpho-agronomic characterization of 96 rice mutant line M5 induced through gamma radiation

    A total of 96 rice mutant lines M5 of Khaw Dawk Mali induced with gamma radiation at doses ranging from 200 to 400 Gray were morpho-agronomically characterized at Muda Agricultural Department Authority (MADA) experimental plot and at Malaysian Institute For Nuclear Technology Research (MINT) laboratory. These mutant lines were selected for resistance to blast disease, which caused by Pyricularia orayzae. Several morphoagronomic characters were evaluated including stability, plant height, number of tiller per hill, flag leaf behavior, flowering and maturity period, grain length and 1000 seeds weight. Variations were found among mutant lines in all morpho-agronomic characters studied. Some mutant lines were better in certain characters as compared to variety Khaw Dawk Mali (Parent). About 20 percent of these mutant lines showed better performance in all morpho-agronomic characters studied as compared to parent will be selected for preliminary yield trial at M6 generation

  15. Sunflower Mutants with Improved Growth and Metal Accumulation Traits Show a Potential for Soil Decontamination

    Over the last two decades, the use of plants has been proposed as an alternative technique to remove toxic metals from contaminated soils. This technique, called phytoextraction, can use either hyperaccumulating species, able to accumulate and tolerate high amounts of metal, but producing low biomass, or high-yielding crops compensating moderate metal accumulation by a high biomass. Both types of plants can be considered for metal removal, but soil decontamination still takes quite a long time. Therefore, plants used for metal removal need to be improved. This paper summarizes our previous and present work aimed at the improvement of sunflowers for phytoextraction by chemical mutagenesis. Improved yield and metal accumulation in sunflower mutants were already observed in the M2 mutant generation, where three new sunflower phenotypes were found: mutants with a significantly enhanced biomass production and no changed metal accumulation; mutants with a slightly improved biomass production and an enhanced metal accumulation in shoots; and mutants with reduced metal uptake. The same alterations in growth and metal accumulation were observed in the following generation. The best M3 sunflower mutants showed a three to five times higher cadmium, a four to five times higher zinc, and a three to five times higher lead extraction, as compared to the control inbred line. The stability of improved traits, yield and metal uptake, was confirmed also in the fourth generation, where mutant lines still provided a significantly enhanced metal extraction. Metal translocation from root to shoot and distribution within the shoot (stem, leaves and flower) of mutant lines and control sunflowers grown on a metal contaminated soil was studied in detail in the fifth generation under greenhouse conditions. Sunflower mutant seedlings show a very good metal translocation capacity after three months of cultivation on contaminated soils; thus the metals were primarily accumulated by sunflower

  16. Sunflower mutants with improved growth and metal accumulation traits show a potential for soil decontamination

    Over the last two decades, the use of plants has been proposed as an alternative technique to remove toxic metals from contaminated soils. This technique, called phytoextraction, can use either hyperaccumulating species, able to accumulate and tolerate high amounts of metal, but producing low biomass, or high yielding crops compensating moderate metal accumulation by a high biomass. Both types of plants can be considered for metal removal, but soil decontamination still takes quite a long time. Therefore plants used for metal removal need to be improved. This paper summarizes our previous and present work aimed at the improvement of sunflowers for phytoextraction by chemical mutagenesis. Improved yield and metal accumulation in sunflower mutants were already observed in the M2 mutant generation, where three new sunflower phenotypes were found: mutants with a significantly enhanced biomass production and no changed metal accumulation; mutants with a slightly improved biomass production and an enhanced metal accumulation in shoots; and mutants with reduced metal uptake. The same alterations in growth and metal accumulation were observed in the following generation. The best M3 sunflower mutants showed a 3-5 times higher Cd, a 4-5 times higher Zn, and a 3-5 times higher Pb extraction, as compared to the control inbred line. The stability of improved traits, yield and metal uptake, was confirmed also in the 4th generation, where mutant lines still provided a significantly enhanced metal extraction. Metal translocation from root to shoot and distribution within the shoot (stem, leaves and flower) of mutant lines and control sunflowers grown on a metal contaminated soil was studied in detail in the 5th generation under greenhouse conditions. Sunflower mutant seedlings show after three months of cultivation on contaminated soils a very good metal translocation capacity; thus the metals were primarily accumulated by sunflower leaves. (author)

  17. relationship between physical characteristics and susceptibility to sitotroga cerealella (oliv.) in paddy rice mutants

    some promising mutants of rice variety Giza 180 induced by using gamma rays were tested for susceptibility to infestation by angoumois grain moth, sitotroga cerealella in relation with grain physical characters. number of F1 progeny and percentage of adult emergence showed that mutants 7/1, 4/5 and 1/7 were the most susceptible o angoumois grain moth, while mutants 13/1,16/1 and 15/6 b were least susceptible . there was positive correlation between number of F1 adult progeny and grain weight loss. the development period of the insect ranged from 33.7 days on 1/7 to 42.9 days on 15/6 b and the adults that emerged from mutants 1/7,4/5,7/1,8/1,15/1 and 11/1 lived longer than those of the other ones. Grains of the mutants with thick and pubescent or intermediate hulls were the least susceptible to attack by this pest. the rice mutants 13/1,16/1,15/6 b and their parental cultivar Giza 180 had the highest grain yield

  18. Mapping and characterization of a tiller-spreading mutant lazy-2 in rice

    LI Peijin; ZENG Dali; LIU Xinfang; XU Dan; GU Dai; LI Jiayang; QIAN Qian

    2003-01-01

    Tiller angle of rice is an important agronomic trait that contributes to breed new varieties with ideal architecture. In this study, we report mapping and characterization of a rice mutant defective in tiller angle. At the seedling stage, the newly developed tillers of the mutant plants grow with a large angle that leads to a "lazy" phenotype at the mature stage. Genetic analysis indicates that this tiller-spreading phenotype is controlled by one recessive gene that is allelic to a reported mutant la. Therefore, the mutant was named la-2 and la renamed la-1. To map and clone LA, we constructed a large mapping population. Genetic linkage analysis showed that the LA gene is located between 2 SSR markers RM202 and RM229. By using the 6 newly-developed molecular markers, the LA gene was placed within a 0.4 cM interval on chromosome 11, allowing us to clone LA and study the mechanism that controls rice tiller angle at the molecular level.

  19. Genetic Analysis and Gene-Mapping of Two Reduced-Culm-Number Mutants in Rice

    2006-01-01

    In the present study, in order to systematically dissect the genetic mechanism of rice (Oryza sativa L.) tilling for the super rice ideotype and the model system of branching development, two ethyl methane sulfonate-induced rice reduced-culm-number (rcn) mutants from the progeny of Nippobare (O. sativa ssp. japonica), namely rcn8 and rcn9, were used. Their maximum tillers were both less than 4. In addition, rcn9 had another major feature of rust-spotted leaves. Allelic tests between these two mutants and seven other recessive few-tiller mutants revealed that they were previously unknown loci. Genetic analysis showed that the rcn traits were all controlled by a pair of different recessive genes, designated as RCN8 and RCNg, respectively. Two F2 populations derived from crosses between the rcn8 or rcn9 mutants and 93-11 were constructed. Linkage analysis using two rcn F2 mapping populations with published simple sequence repeat markers demonstrated that the RCN8 and RCN9 genes were mapped on the long arm of chromosome 1 (119.6 cM) and the short arm of chromosome 6 (63.6 cM),respectively. The results of the present study are beneficial to map-based cloning and functional analysis of the RCN8 and RCN9 genes.

  20. Identification and characterization of some aromatic rice mutants using amplified fragment length polymorphism (AFLP) technique

    Accurate identifying of the genotypes is considered one of the most important mechanisms used in the recording or the protection of plant varieties. The investigation was conducted at the experimental form belonging to the egyptian Atomic Energy Authority, Inshas. The aim was to evaluate grain quality characteristics and molecular genetic variation using Amplified Fragment Length Polymorphism (AFLP) technique among six rice genotypes, Egyptian Jasmine aromatic rice cultivar and five aromatic rice mutants in (M3 mutagenic generation). Two mutation (Egy22 and Egy24) were selected from irradiated Sakha 102 population with 200 and 400Gy of gamma rays in the M2 generation, respectively, and three mutations ( Egy32, Egy33, and Egy34) were selected from irradiated Sakha 103 population with 200, 300, 400Gy of gamma rays in the M2 generation, respectively. The obtained results showed that the strong aroma was obtained for mutant Egy22 as compared with Egyptian Jasmine rice cultivar (moderate aroma). Seven primer combinations were used through six rice genotypes on the molecular level using AFLP marker. The size of AFLP Fragments Were Ranged from 51- 494bp. The total number of amplified bands was 997 band among them 919 polymorphic bans representing 92.2%. The highest similarity index (89%) was observed between Egyptian Jasmine and Egy32 followed by (82%) observed between Egyptian Jasmine and Egy34. On the other hand, the lowest similarity index was (48%) between Egyptian Jasmine and Egy24. In six rice genotypes, Egy24 produced the highest number of the AFLP makers giving 49 unique markers (23 positive and 26 negative), then Egy22 showed 23 unique markers (27 positive and 6 negative) while Egy33 was characterized by 17 unique markers (12 positive and 5 negative). At last Egyptian Jasmine was discriminated by the lowest number of markets, 10 (6 positive and 4 negative). The study further confirmed that AFLP technique was able to differentiate rice genotypes by a higher number

  1. Socio-economic impacts of mutant rice varieties in southern Vietnam

    Rice plays an important role of socio-economic development in Vietnam, especially in Mekong River Delta (MRD) where is more than half of the total and 90% of national export rice. Rice variety improvement is main project in national breeding program. However, no mutant rice variety (MRV) was cultivated in MRD before 1995. Recently, 8 rice mutants occupy 10.3% of total modern varieties in Southern Vietnam. The mutated characters developed so far consist of better resistance to lodging, disease and insect damages, higher tolerance to soil stresses such as acid sulphate soil, drought etc, and also earliness and higher yield potential. Some best mutant varieties: VND95-19, VND95-20, VND99-3, TNDB-100 have been released for large-scale production in MRD. Among them, VND95-20 has become one of the top 5 varieties for export and grown annually more than 300,000ha in Southern Vietnam. In combination with hybridization method, some mutants gave promising recombinants. Selected varieties as VN121, VN24-4, OM2717, OM2718 have been released into production. Successful combination of aromatic character with short duration, high yield, tolerant to new diseases (GSV and RSV) and insects (BPH), consequently reduction of 2-3 spraying times of pesticide / crop, supported for health and environmental protection. For 8 past years under IAEA TC project, total cultivated area of MRV was more than 2.54 millions ha in Southern Vietnam. Until 2008, 8 mutant varieties produced the added return of 374 millions USD for past years and continue producing added return for farmers. Eight MRV of VND95-20, VND99-3, TNDB100, VND95-19, OM2717, OM 2718, VN 121 and VN24-4 occupied the added return values as 300.00; 9.0; 37.5; 6.0; 12.0; 8.4; 0.8 and 0.7 millions USD, respectively. Application of MRV is reduced 2-3 spraying times / crop due to their tolerance to diseases and insects. MRV are used in strategy program of 'Eradicate hunger and alleviate poverty' of different national projects, particularly

  2. Socio-Economic Impacts of Mutant Rice Varieties in Southern Vietnam

    Rice production plays an important role in the socio-economic development of Vietnam, especially in the Mekong River Delta (MRD) region, which is responsible for more than half of the total and 90% of the national rice export. Before 1995, no mutant rice varieties (MRVs) were cultivated in the MRD. At present, rice variety improvement is the main focus of the national breeding programme and 8 rice mutants have been developed, occupying 10.3% of the total modern varieties in Southern Vietnam. The mutant varieties developed so far have better resistance to lodging, disease and insect damages, higher tolerance to soil stresses such as acid sulphate soil, drought etc., and also exhibit earliness and higher yield potential. Some of the best mutant varieties, namely VND95-19, VND95-20, VND99-3, TNDB-100 have already been released for large-scale production in the MRD. VND95-20 has become one of the top 5 exported varieties and is grown annually on more than 300,000 ha in Southern Vietnam. Some of these mutants have given promising recombinants through hybridization and in particular the varieties VN121, VN124, OM2717 and OM2718 have been released into production. A successful combination of aromatic characteristics, short duration, high yield, tolerance to new diseases (GSV and RSV) and insects (BPH), and consequent reduction of spraying times of pesticide per crop, have greatly benefitted health and environmental protection. During the past 8 years under the IAEA Technical Co-operation (TC) project, the total cultivated area of MRVs in Southern Vietnam has been more than 2.54 millions ha. Until 2008, the 8 rice mutant varieties produced an added return of 374 million USD over the previous years and continue to produce added return for farmers. More specifically, VND95-20, VND99-3, TNDB100, VND95-19, OM2717, OM2718, VN121 and VN124 returned 300.00, 9.0, 37.5, 6.0, 12.0, 8.4, 0.8 and 0.7 million USD, respectively. The application of MRVs reduced spraying times per crop

  3. Comparative proteomic analysis provides new insights into cadmium accumulation in rice grain under cadmium stress

    Xue, Dawei, E-mail: dwxue@hznu.edu.cn [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Jiang, Hua [State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Science, Hangzhou 310021 (China); Deng, Xiangxiong; Zhang, Xiaoqin [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Wang, Hua [State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Science, Hangzhou 310021 (China); Xu, Xiangbin [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Hu, Jiang; Zeng, Dali [State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Guo, Longbiao, E-mail: guolongbiao@caas.cn [State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Qian, Qian, E-mail: qianqian188@hotmail.com [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China)

    2014-09-15

    Graphical abstract: - Highlights: • Cd is the most toxic heavy metal and is a major pollutant in rice grains. • The mechanism of Cd accumulation in rice grains has not been well demonstrated. • Proteomics analysis is carried out and the verification is implemented by QPCR. • Proteins associated with ROS and photosynthesis showed large variation in expression. - Abstract: Rice is one of the most important staple crops. During the growth season, rice plants are inevitably subjected to numerous stresses, among which heavy metal stress represented by cadmium contamination not only hindering the yield of rice but also affecting the food safety by Cd accumulating in rice grains. The mechanism of Cd accumulation in rice grains has not been well elucidated. In this study, we compare the proteomic difference between two genotypes with different Cd accumulation ability in grains. Verification of differentially expressed protein-encoding genes was analyzing by quantitative PCR (QPCR) and reanalysis of microarray expression data. Forty-seven proteins in total were successfully identified through proteomic screening. GO and KEGG enrichment analysis showed Cd accumulation triggered stress-related pathways in the cells, and strongly affecting metabolic pathways. Many proteins associated with nutrient reservoir and starch-related enzyme were identified in this study suggesting that a considerably damage on grain quality was caused. The results also implied stress response was initiated by the abnormal cells and the transmission of signals may mediated by reactive oxygen species (ROS). Our research will provide new insights into Cd accumulation in rice grain under Cd stress.

  4. Metal Contamination in Nullah Dek Water and Accumulation in Rice

    M. SARFRAZ; S. M. MEHDI; G. HASSAN; S. T. ABBAS

    2007-01-01

    A research study was carried out to determine the electrical conductivity (EC), residual sodium carbonate (RSC), sodium adsorption ratio (SAR), pH and metals in metal-polluted irrigation water from a nullah and those in soils over a period of time, and the effect of metals on rice yield and metal concentrations in rice grain and straw. Two sites (Ⅰ and Ⅱ) were selected on the bank of Nullah Dek at Thatta Wasiran in Sheikhupura District (Pakistan), with two rice varieties, Super Basmati and Basmati 385, at both sites. Water samples were collected during rice crop growth at 15-day intervals from August 3 to November 1, 2002. The results showed that Nullah Dek water had an EC >1.0 dS m-1 and RSC of 2.78-4.11 mmolc L-1, which was hazardous for crops, but the SAR was within the safe limit. Cu, Mn Cd and Sr were also within safe limits. The soil analysis showed that Site Ⅱ was free from salinity/sodicity, whereas Site Ⅰ was saline sodic. Among metals, Zn was sometimes deficient, Cu, Mn and Fe were adequate, and Sr, Ni and Cd were within safe limits in the soil at both the sites. After the rice crop harvest, concentrations of all metals tested were usually slightly increased, being higher in the upper soil layer than the lower. In addition, Basmati 385 produced higher rice grain and straw yield than Super Basmati. Chemical analysis of rice grain indicated the presence of Zn, Cu, Fe, Mn, Pb and Sr, whereas rice straw contained Zn, Cu, Fe, Mn and Sr, with Cd and Ni both being found in minute quantities.

  5. Gamma ray induced seedling injury and chlorophyll mutants in two varieties of rice

    Dry, well filled seeds of rice cultivars Basmati and Phalguna were irradiated with 20, 30, 40, and 50 kR gamma ray doses with a view to study their radio sensitivity in inducing seedling injury and chlorophyll mutants. In general, the percentage of germination, survival, seedling height and leaf number decreased in the irradiated population. The spectrum of chlorophyll mutants induced include albino, viridis, xantha and other categories like striata, zebra and maculata. Viridis was more predominant in Basmati whereas xantha was more in phalguna. (author). 7 refs., 2 tabs

  6. Genetic variation of space flight carried rice and mutant analysis by AFLP molecular marker

    Rice seeds were carried by 'Shenzhou No.3' space shuttle, a mutant with golden chaff, stem and leaf was selected and named Golden 1 after the seeds returned to the earth. Except the golden color, other traits of Golden 1 are no obviously different with its original material H9808. Genetic analysis identified that color variation was control by a pair of recessive gene. The DNA fragments of the mutant were compared with its parent by AFLP molecular markers. Five specific bands were found through a serial selection. (authors)

  7. Genetic Analysis and Gene Mapping of Short Root Mutant Rice ksr1

    NING Yong-qiang; DING Wo-na; ZHU Shi-hua; Yu Hang-wei; Yu Hang; Lu Kai-xing

    2011-01-01

    A short root mutant ksr1 with the Kasalath background was isolated from an EMS-mutagenized population in rice.The root length of 6-day-old ksr1 seedlings was only about 20% of the wild type.Genetic analysis indicated that the short root phenotype of ksr1 was controlled by a recessive mutation in a single nuclear-encoded gene.To map the ksr1 mutation,an F2 population was generated by crossing the ksr1 mutant with Nipponbare.The KSR1 locus was linked to the SSR marker RM1223 on rice chromosome 4.Eight new SSR markers and two InDet markers were developed around this marker.KSR1 gene was further mapped to a 155 kb region,flanked by the InDel marker 4-24725K and the SSR marker RM17182.

  8. Genetic analysis and gene mapping of a mutant dwarf gene IGA-1 in rice

    The rice material, Hangai-1, which studied in this paper, was a stabile dwarf mutant by space mutation of rice cultivar Texianzhan 13(indica). Genetic analysis showed that its dwarf trait was controlled by two recessive semi-dwarf genes, sd1 and a new semi-dwarf gene, named as iga-1. The new semi-dwarf gene iga-1 was located between microsatellite markers RM6645 and RM3837 on chromosome 5, the genetic distances between them were 0. 07cM and 1.21 cM, respectively. The iga-1 gene is possibly a multiple allele to the d-1 gene. The semi-dwarf mutant with the new semi-dwarf gene iga-1 was found insensitive to gibberellin 3(GA3). (author)

  9. Rhodobacter sphaeroides mutants which accumulate 5-aminolevulinic acid under aerobic and dark conditions.

    Nishikawa, S; Watanabe, K; Tanaka, T; Miyachi, N; Hotta, Y; Murooka, Y

    1999-01-01

    The photosynthetic bacterium Rhodobacter sphaeroides accumulates 5-aminolevulinic acid (ALA), which is a precursor in tetrapyrrole biosynthesis, under light illumination and upon addition of levulinic acid as an inhibitor of ALA dehydratase. To generate an industrial strain which produces ALA in the absence of light, we sequentially mutated R. sphaeroides CR-286 using N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The mutant strains were screened by cultivating in the absence of light and assayed for ALA by the Ehrlich reaction in a 96-well microtiter plate. The mutant strain CR-386, derived from R. sphaeroides CR-286, was selected as a mutant that exhibited significant ALA accumulation. While CR-286 required light illumination for ALA production, CR-386 was able to accumulate 1.5 mM ALA in the presence of 50 mM glucose, 60 mM glycine, 15 mM levulinic acid and 1.0% (w/v) yeast extract under conditions of agitation in the absence of light. The mutant strain CR-450, derived from strain CR-386, was selected further as a mutant that exhibited significant ALA accumulation but no accumulation of aminoacetone, analogue of ALA. CR-450 accumulated 3.8 mM ALA under the same conditions. In the presence of 50 mM glucose, 60 mM glycine, 5 mM levulinic acid and 1.0% (w/v) yeast extract, the mutant strain CR-520, derived from strain CR-450, and strain CR-606, derived from strain CR-520, accumulated 8.1 mM and 11.2 mM ALA, respectively. In batch fermentation, the strain CR-606 accumulated 20 mM ALA over 18 h after the addition of glycine, levulinic acid, glucose and yeast extract. PMID:16232557

  10. Practical value of induced mutants of rice resistant to bacterial leaf blight

    The thermal neutron induced mutants of rice resistance to bacterial leaf blight (BLB), designated M41 and M57, in which resistance is conditioned by a single gene and polygenes, respectively, were evaluated for their practical value for breeding rice varieties resistant to BLB. Three experiments were carried out. (1) The nature of the resistance of the mutants was examined from various aspects. The two mutants were resistant to the Japanese and Philippines BLB differential races. The resistance of M41 was found to vary to some extent with the planting year, the amount of nitrogen fertilizer applied and the plant age compared with M57, although the resistance level of M41 was higher than that of M57. (2) BLB resistant F3 or F4 lines derived from crosses of the mutants x original variety Harebare were analysed for some agronomic traits. One of the M57 x Harebare lines that had a good shape and a higher yielding capacity was not released as a commercial variety because of the poor taste of the rice. All the M41 x Harebare lines carried some negative traits inherited from M41, e.g. a lower yielding capacity, an inadequate mature husk colour, etc. (3) The F3 lines from crosses of the leading Japanese varieties Koshihikari and Akitakomachi x M41 were also analysed for their resistance and some other agronomic traits. Some of the resistant lines were found to exhibit favourable traits, e.g. good taste of the rice, which may lead to the development of new commercial varieties in the near future. (author). 14 refs, 9 figs 2 tabs

  11. Induction of mutations in Thai rice varieties and subsequent selection and testing of beneficial mutant lines

    Ionizing radiations were first used in the Thailand Rice Breeding Program in 1955 when seeds of two recommended varieties were sent to the United States of America for treatment. As a result, five promising mutant lines are at present in regional yield tests where they are being considered for recommendation to rice growers. During the period 1960-1961 an unsuccessful attempt was made to induce resistance to blast in three susceptible varieties by exposing seeds to a local source of ionizing radiation In 1964, after an elapse of about 4 years, another attempt was made to utilize ionizing radiations in the breeding program by treating seeds of two recommended varieties. In 1965, a co-ordinated rice mutation breeding program was initiated under the auspices of the Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture which resulted in treating seeds of twelve different rice varieties with both ethyl methane sulphonate and gamma rays from a 60Co gamma cell. The results so far indicate that mutagenic agents have been successful in producing genetic variability. Differences in heading date, mature plant height and plant type are frequently observed in the M2 and M3 generations. Several lines obtained from two of the irradiated varieties have exhibited a higher degree of resistance to blast than the parental material. From 15-kR treatments of non-glutinous varieties, mutants with glutinous endosperm have been obtained. Not all varieties gave the same response to treatment. (author)

  12. Characterization and Mapping of a Salt-Sensitive Mutant in Rice (Oryza sativa L.)

    Jingwei Zhou; Fuzheng Wang; Ping Deng; Wen Jing; Wenhua Zhang

    2013-01-01

    A salt-sensitive mutant designated rice salt sensitive 2 (rss2) was isolated from the M2 generation of the rice cultivar Nipponbare (Oryza sativa L.ssp.japonica) mutagenized with ethyl methanesulfonate (EMS).This mutant exhibited a greater decrease in salt tolerance with a significant increase in Na+ content in its shoots.Genetic analysis indicated that the increase in Na+ in rss2 was controlled by a single recessive gene.Further genome-wide analysis of the linkage map constructed from the F2 population of rss2/Zhaiyeqing 8 (ZYQ8) showed that two quantitative trait loci (QTLs) on chromosomes 1 and 6 were responsible for the Na+ concentration in shoots,which explained 14.5% and 53.3%,respectively,of the phenotypic variance.The locus on chromosome 1,but not that on chromosome 6,was also detected in the F2 population of Nipponbare/ZYQ8,suggesting that the QTL on chromosome 6 was responsible for the salt sensitivity in rss2.By analyzing the recombination events in 220 mutant individuals of an enlarged mapping population of rss2/ZYQ8,the rss2 locus was precisely mapped to an interval of 605.3 kb between insertion/deletion (InDel) markers IM21962 and IM22567.This finding will facilitate the cloning of the rss2 locus and provide insight into the physiological mechanisms of salt sensitivity in rice.

  13. Genetic analysis and fine mapping of a lax mutant in rice

    WANG Yun; XIAO Han; QIAN Qian; LI Hongchang; LI Shigui; ZHU Lihuang

    2003-01-01

    We have analyzed a lax mutant that exhibits altered panicle architecture in rice. The primary and secondary rachis-branches are normally initiated and each branch ends in a terminal spikelet, but all the lateral spikelets are absent and the terminal spikelet displays variegated structures in the mutant. An F2 population from the cross between thelax mutant and a japonica variety, Wll, was constructed and analyzed. Using microsatellite and CAPS markers, the lax locus was mapped on the long arm of chromosome 1,co-segregated with a CAPS marker, LZ1, within an interval of 0.28 cM between a CAPS marker, HB2, and a microsatellite marker, MRG4389. RT-PCR analysis revealed that the expressions of the rice B-function MADS-box genes OsMADS2, OsMADS4, OsMADS16 and OsMADS3 were significantly reduced, whereas the expression of the rice A-function ene RAP1A was not altered.

  14. Selenium Accumulation and Antioxidant Status of Rice Plants Grown on Seleniferous Soil from Northwestern India

    Sucheta SHARMA; Reeti GOYAL; Upkar Singh SADANA

    2014-01-01

    Greenhouse experiment was conducted to investigate selenium accumulation and its antioxidant response in two rice varieties (PR116 and Pusa Basmati 1121) grown on normal and seleniferous soils. The plant growth was reduced at early developmental stages and flowering was delayed by a period of 10 d on seleniferous soil. Selenium accumulation increased by 3–20 and 13–14 folds in leaves, 18 and 3 folds in grains from Pusa Basmati 1121 and PR116 varieties, respectively. Selenium accumulation in leaves from rice plants grown on seleniferous soil resulted in significant increase in chlorophyll content, hydrogen peroxide, proline, free amino acids, total phenol and tannin contents. Lipid peroxidation levels and peroxidase activities in leaves increased whereas catalase activity showed a reverse trend. It is concluded that selenium accumulation decreased dry matter content in rice during crop development but these plants were able to combat selenium toxicity by inducing alterations in their defense system.

  15. Preliminary report on the rice blast resistance of space-induced mutants derived from rice cultivar 'Taihang-68'

    To screen the blast resistance mutants, the resistance of SP1 progenies derived from rice variety Taihang-68 were evaluated after satellite flight by representative blast isolate GD0193 which had a broad pathogenic spectra, and then primary genetic analysis of resistant mutants and mapping of resistance gene, as well as resistance spectra at seedling and neck blast resistance at maturity were performed. The results showed that space-mutation was effective method to change the blast resistance of Taihang-68. The screened resistant mutants TH1 and TH2 showed that resistance to isolate GD0193 no disjunction and separation respectively, and the resistance separation ratio of TH2 indicated that its resistance was controlled by one pair of major genes, which was preliminary mapped on the long arm of chromosome 11. In blast resistance spectra and neck blast resistance, TH1 and TH2 were both enhanced remarkable compared with the wild-type at seedling and maturity, and their resistance could be inherited, the blast resistance of these two mutants were also increased comparing with several main cultivars in South China. (authors)

  16. Isolation and characterization of a mutant defective in triacylglycerol accumulation in nitrogen-starved Chlamydomonas reinhardtii.

    Hung, Chun-Hsien; Kanehara, Kazue; Nakamura, Yuki

    2016-09-01

    Triacylglycerol (TAG), a major source of biodiesel production, accumulates in nitrogen-starved Chlamydomonas reinhardtii. However, the metabolic pathway of starch-to-TAG conversion remains elusive because an enzyme that affects the starch degradation is unknown. Here, we isolated a new class of mutant bgal1, which expressed an overaccumulation of starch granules and defective photosynthetic growth. The bgal1 was a null mutant of a previously uncharacterized β-galactosidase-like gene (Cre02.g119700), which decreased total β-galactosidase activity 40% of the wild type. Upon nitrogen starvation, the bgal1 mutant showed decreased TAG accumulation mainly due to the reduced flux of de novo TAG biosynthesis evidenced by increased unsaturation of fatty acid composition in TAG and reduced TAG accumulation by additional supplementation of acetate to the culture media. Metabolomic analysis of the bgal1 mutant showed significantly reduced levels of metabolites following the hydrolysis of starch and substrates for TAG accumulation, whereas metabolites in TCA cycle were unaffected. Upon nitrogen starvation, while levels of glucose 6-phosphate, fructose 6-phosphate and acetyl-CoA remained lower, most of the other metabolites in glycolysis were increased but those in the TCA cycle were decreased, supporting TAG accumulation. We suggest that BGAL1 may be involved in the degradation of starch, which affects TAG accumulation in nitrogen-starved C. reinhardtii. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27060488

  17. Genetic Analysis and Molecular Mapping of Light-Sensitive Red-Root Mutant in Rice

    ZHANG Jun-zhi; LIU Xiao; LI Chao; XIAO Ke; DONG Yan-jun

    2009-01-01

    The light-sensitive red-root mutant, designated as HG1, was newly observed from an indica rice variety, Nankinkodo, when seedlings were grown with roots exposed to natural light. The root color of the mutant began to turn slight-red when the roots were exposed to the light at the intensity of 29 μmol/(m2·s), then turned dark-red at the light intensity of 180 μmol/(m2·s), suggesting that the root color of the mutant was evidently sensitive to light. Furthermore, genetic analysis showed that the character of light-sensitive red-root of the HG1 mutant was controlled by a single dominant gene, tentatively designated as Lsr. With simple sequence repeat markers, Lsr gene was located between the markers RM252 and RM303 on chromosome 4 with the genetic distances of 9.8 cM and 6.4 cM, respectively. These results could be useful for fine mapping and cloning of Lsr gene in rice.

  18. Genetic Analysis and Gene Mapping of Light Brown Spotted Leaf Mutant in Rice

    FENG Bao-hua; YANG Yang; SHI Yong-feng; LIN Lu; CHEN Jie; WEI Yan-lin; Hei LEUNG

    2013-01-01

    A light brown spotted-leaf mutant of rice was isolated from an ethane methyl sulfonate (EMS)induced IR64 mutant bank.The mutant,designated as Ibsl1 (light brown spotted-leaf 1),displayed light brown spot in the whole growth period from the first leaf to the flag leaf under natural summer field conditions.Agronomic traits including plant height,growth duration,number of filled grains per panicle,seed-setting rate and 1000-grain weight of the mutant were significantly affected.Genetic analysis showed that the mutation was controlled by a single recessive gene,tentatively named Ibsl1(t),which was mapped to the short arm of chromosome 6.By developing simple sequence repeat (SSR) markers,the gene was finally delimited to an interval of 130 kb between markers RM586 and RM588.The Ibsl1(t) gene is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region.The genetic data and recombination populations provided will facilitate further fine-mapping and cloning of the gene.

  19. Identification of the Second Mutation of BADH2 Gene Derived from Rice Mutant Lines Induced by Gamma Rays

    I. Ishak

    2016-01-01

    The BADH2 gene acts as suppressor of 2-acetyl-1-pyrolline (2AP) biosynthesis in plants. 2AP is the volatile compound which provides fragrance in rice. Biosynthesis of 2AP occurs when BADH2 loses its function as suppressor gene. Aromatic rice cultivars naturally incur mutation of BADH2 gene at 8 bp. In this experiment, aromatic mutant rice lines derived from irradiation of Sintanur cultivar by gamma rays with dose of 100 Gy were studied in molecular level. These mutant lines were characterize...

  20. Development and Substance Accumulation of Caryopsis in Transgenic Rice with Antisense Wx Gene

    CHEN Gang; WANG Zhong; LIU Qiao-quan; KIONG Fei; GU Yun-jie; GU Guo-jun

    2006-01-01

    The development and substance accumulation of rice caryopsis were studied by using the transgenic japonica and indica rice with antisense Wx gene. The weight of caryopses in transgenic rice was lower than that in non-transgenic one, and the reduction in weight was significantly correlated to the reduction in amylose content. In caryopsis of transgenic rice, the number of endosperm cells was less than that in caryopsis of non-transgenic one, but the proliferation speed was considerably higher during the first six days after flowering (DAF). During the first nine DAF, the soluble sugar content of transgenic rice caryopsis was less than that of the non-transgenic one, but the situation was reverse after nine DAF. Moreover, the total starch content also declined with the decrease in amylose content of transgenic rice caryopsis, while the amylopectin content increased accordingly. Therefore, the composition of starch in caryopsis also changed, but it did not affect the accumulation of protein in transgenic rice caryopsis.

  1. Characterization and mapping of a white panicle mutant gene in rice

    2003-01-01

    A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mutant exhibits white stripes on its basal leaves while the panicles, rachis and pedicel are milky white colored at flowering stage. Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene, tentatively termed as wp(t). Using microsatellite markers, the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8 cM, respectively, and co-segregated with the marker of SSR17 on rice chromosome 1.

  2. Genetic analysis of plant height in induced mutants of aromatic rice

    Inheritance of plant height in five gamma-ray induced mutants of aromatic rice cultivar Gobindabhog was studied through 6 x 6 diallel cross and segregation analyses. Diallel analysis revealed presence of additive and non-additive gene action with the preponderance of the latter. Proportion of dominant and recessive alleles was distributed unequally among the parents. The direction of dominance was towards tallness. The number of groups of genes was found to be three. The segregation analysis indicated the role of a single major recessive gene for height reduction in three mutants and, in another mutant, a single major recessive gene with negative modifiers. The other semi-dwarf mutant had two major recessive genes with almost equal effect in height reduction. The mutant allele(s) of the latter two mutants were non-allelic to sd sub(1) gene, which could be used as an alternative source of Dee Gee Woo Gen to widen the genetic diversity in semi-dwarfism

  3. RNA Interference-mediated Silencing of Phytochelatin Synthase Gene Reduce Cadmium Accumulation in Rice Seeds

    2007-01-01

    Phytochelatins (PCs) play an important role in heavy metal resistance and accumulation. To reduce the accumulation of cadmium (Cd) in rice seeds, the expression of phytochelatin synthase (PCS) gene OsPCS1 was suppressed by RNA interference (RNAi). A hairpin construct of a PCS fragment was designed in the pRNAi-OsPCS1 under the control of ZMM1, a seed-specific promoter from maize. The construct was introduced into rice (japonica) through Agrobacterium tumefaciens. The RNAi rice plantlets were selected and cultivated in pots exposured to 10 mg/kg Cd. The transcriptional level of OsPCS1 declined in seeds of some RNAi rice compared to the wild type. As a result Cd accumulation was reduced by about half in the seeds of RNAi rice. As expected, no apparent difference of growth appeared between RNAi and wild-type plants. The results suggest that this new approach can be used to control heavy metal accumulation in crops.

  4. Genetic analysis and gene mapping of a dwarf mutant rice CHA-1

    A special dwarf mutant rice CHA-1, studied in this paper, was a stabile and inherited rice material selected from the induced generation derived from rice variety Tehuazhan which had been flown on a high space balloon. In order to investigate the inheritance of the dwarf genes in CHA-1, the crosses between CHA-1 and high variety Huiyangzhenzhuzao were carried out. Genetic analysis of the height in their F2 generation showed that the new mutant gene h (named as h temporarily) from CHA-1 was a major recessive gene which linked with sd-1 in a certain extent. The two genes had complementary interaction and controlled the dwarf trait of CHA-1 together. Therefore, the genotype of CHA-1 was hhsd- 1sd-1. To map the locus of the dwarf gene h, bulked-segregate analysis and recessive-class analysis in F2 generation from the cross between CHA-1 and variety 02428 were used to screen SSR molecular markers linked with the dwarf gene. The result showed that the dwarf gene h was located on chromosome 1, with a genetic distance of 4.715 cM from SSR marker RM302 and a genetic distance of 5.915 cM from the semi-dwarf gene sd-1. (author)

  5. Rice Brittleness Mutants: A Way to Open the 'Black Box' of Monocot Cell Wall Biosynthesis

    Baocai Zhang; Yihua Zhou

    2011-01-01

    Rice is a model organism for studying the mechanism of cell wall biosynthesis and remolding in Gramineae.Mechanical strength is an important agronomy trait of rice(Oryza sativa L.)plants that affects crop lodging and grain yield.As a prominent physical property of cell walls,mechanical strength reflects upon the structure of different wall polymers and how they interact.Studies on the mechanisms that regulate the mechanical strength therefore consequently results in uncovering the genes functioning in cell wall biosynthesis and remodeling.Our group focuses on the study of isolation of brittle culm(bc)mutants and characterization of their corresponding genes.To date,several bc mutants have been reported.The identified genes have covered several pathways of cell wall biosynthesis,revealing many secrets of monocot cell wall biosynthesis.Here,we review the progress achieved in this research field and also highlight the perspectives in expectancy.All of those lend new insights into mechanisms of cell wall formation and are helpful for harnessing the waste rice straws for biofuel production.

  6. Selection for bacterial leaf-blight (Xanthomonas oryzae) and sheath-blight (Rhizoctonia oryzae) resistant mutants in a collection of early rice mutants

    Two of the most important and common rice diseases in Indonesia are bacterial leaf blight (BLB) and sheath blight (SB). The best rice yielding varieties in Indonesia, Pelita I/1 and IR5, were treated with gamma radiation and EMS. All the early maturing mutants which were selected from M2 and M3 generations, and afterwards in the M8 generation we tested for their reaction to bacterial leaf blight and sheath blight. Pelita I/1 is moderately resistant to BLB and moderately susceptible to SB, but IR5 is susceptible to BLB or SB. At 30 and 60 days after transplanting, 107 early maturing mutants were inoculated with BLB. The bacteria were isolated from three different rice fields, and grown into Wakimoto media. Inoculation was done by the cutting method with suspension of 10-7-10-8cell/cm3. The virulence of bacteria isolated from the three fields was different. Resistant mutants were only observed in the Pelita I/1 early mutant collection; however, moderate resistance was found in the IR5 early mutants collection. At late growth stage the plant seems relatively more resistant to BLB. Early mutants of Pelita I/1 were inoculated with fungus SB following the procedure of the International Rice Sheath Blight Nursery (IRSHBN). Of 96 mutants, 55 were susceptible and 41 were moderately susceptible. Pelita I/1 was moderately susceptible with 48% damage and, compared with this, 9 mutant lines showed less than 40% damage. Selection was also carried out by natural infection; however, owing to ecoclimatic conditions the result was not convincing. (author)

  7. A new mutant indica rice diseases resistance variety 'Zhe101' by space mutation

    Air-dried seeds of indica rice variety 'Zhe 9248' were carried by recoverable satellite, mutagenic effects of outer space environment of 175-354 km on indica rice was studied. Wider segregation spectrum of major characters, such as plant height, growth period duration (GPD), length of panicle, 1000-grain weight and so on, were found in the SP2 generation. A mutant variety 'Zhe101' selected from the space mutation progenies was improved significantly in GPD, disease resistance and yield. It was released in Oct. 2005 as an early indica rice in the double-cropped Yangtze River area. It has high, stable yield potential under normal fertilization. In Zhejiang Regional Trials in 2003-2004, it yielded 7189.5 kg/ha, 3.7% higher than the check' Jiayu293'. Blast resistance of 'Zhe 101' spared to be obvious superior to the parent and check. The average scale of leaf blast was only 0.8, the neck node blast was 1.5, causes a damage rate is only 2.6% on average. The average scale of bacterial leaf blight disease resistance was 4.0. The successful breeding of 'Zhe 101' showed that space mutation is an effective method to simultaneously improve multi-characteristics, and especially in diseases resistance improvement of rice. (authors)

  8. Morphology and mapping analysis of rice (Oryza sativa L.) clustered spikelets (Cl) mutant

    2003-01-01

    The rice clustered spikelets (Cl) mutant exhibits a phenotype that most of branch apical have 2-3 spikelets clustered together. SEM (scanning electron microscope) observation suggested that the Cl gene controlled branch apical development, and influenced the terminal spikelets elongation. The spikelet number was reduced in mutant, indicating that Cl may also have an effect on spikelet number. To map Cl locus, two F2 mapping populations derived from the crosses between the Cl and ZhongHua11, and Cl and ZheFu802 were constructed, respectively. The Cl locus was roughly mapped between two CAPS markers, CK0214 and SS0324. A further fine mapping analysis showed that the Cl locus was mapped between makers R0674E and Cl2560, with genetic distances of 0.2 and 2.1 cM, respectively. Then we found a PAC contig spanning Cl locus, the region was delimited to 196 kb. This result was useful for cloning of the Cl gene. Allelism test demonstrated that Cl was allelic to Cl2, another rice clustered spikelets mutant.

  9. The use of semi-dwarf mutants as breeding materials in rice

    Thailand's work on induced mutation in rice breeding began in 1955 using traditional tall varieties which were deficient in blast resistance. Over the years, the work has evolved through a series of changes to induction of mutants for improving the high yielding varieties. In 1981, efforts were begun to induce and identify semi-dwarf types from some of the popular traditional tall varieties. The objective was to identify new sources of semi-dwarfness different from the DGWG gene which is presently used in most of the world's new rice varieties. Mutants have been obtained from three popular Thai varieties which are significantly shorter in height than their parent variety. Crosses have been made back to the parent variety and to RD1 and IR36 to conduct a genetic analysis of the height genes. Data are not yet available but some F1 generation plants have been transplanted in the field. Results are expected to be available at the end of 1982. Mutants from the variety LA 29 appeared especially promising and were also crossed with other varieties and experimental lines for use in the conventional breeding program. (author)

  10. Identification and Genetic Mapping of a Lesion Mimic Mutant in Rice

    MA Jian-yang; CHEN Sun-lu; ZHANG Jian-hui; DONG Yan-jun; TENG Sheng

    2012-01-01

    A lesion mimic stripe mutant,designated as Ims1 (lesion mimic stripe 1),was obtained from the M2 progeny of a 60Co Y-radiation treated japonica rice variety Jiahua 1.The Ims1 mutant displayed propagation type lesions across the whole growth and developmental stages.Physiology and histochemistry analysis showed that the mutant exhibited a phenotype of white stripe when grown under high temperature (30 ℃),and the lesion mimic caused by programmed cell death under low temperature (20 ℃).The genetic analysis indicated that this lesion-mimic phenotype is controlled by a single locus recessive nuclear gene.Furthermore,by using simple sequence repeat markers and an F2 segregating population derived from two crosses of Ims1 × 93-11 and Ims1 × Pei'ai 64S,the Ims1 gene was mapped between markers Indel1 and MM0112-4 with a physical distance of 400 kb on chromosome 6 in rice.

  11. Developing mutant rice high in resistant starch fighting for diabetes-affected people

    syndrome. To execute the dietary-prevention strategy and the non-insulin-dependent diabetes treatment, developing for rice high in RS is of particular interest and an accepted means of preventing diet-related disease. Serial of mutants high in RS in the hot cooked rice and processed was induced from the leading commercial rice varieties in China i.e. R7954, 9311, II-32B, Zhongzhe B, K17B, Gang46B. Despite obviously low RS content in the raw milled rice, RS content in the cooked an processed rice of mutants were 10-100 times higher than that of the wild type and common rice, the highest RS content is about 15% in mutants. Obvious differences in physicochemical properties, starch granule morphology, pasting properties, thermal properties, and X-ray diffraction pattern were observed among mutants, wild type, and common rice. The high-RS mutants were unique in natural starch structure and were characterized by the higher λmax of absorbance and blue value of iodine-binding starch complex, higher percentage of oval-shaped granules and bigger oval size, lower onset temperature, peak temperature, final temperature, and enthalpy of gelatinization, lower crystallinity, containing a higher percentage of intermediate chains of amylopectin and displaying a mixture of B- and V-type that was more resistant to starch hydrolysis by alpha-amylase. Starch hydrolysises in vitro by porcine pancreatic α-amylase tends to be incomplete with a lower rate and extent in the cooked or processed high-RS rice. In practically consumed as the staple foods by diabetes and animal-feeding test, the GI levels in two hours after eating were significantly lower than that of common rice, and the increased satiety sensation was clearly felt, which is the key important for the diabetes to eat the enough to meet the basic 'Always hungry' problem. The reduction in the amount of inhibiting-digestion chemicals and insulin and improvement of health body were quickly observed in the long-term eating testing. Based on

  12. High yielding semidwarf Pokkali rice mutants tolerant to abiotic stresses of coastal saline ecosystem

    The most popular rice varieties in the pokkali tract of Kerala State, India are Pokkali, Cheruvirippu, VTL-3 and VTL- 4. These varieties are tall, lodging genotypes having tolerance to complex abiotic stresses (salinity, acidity and submergence). About 50% yield is lost due to lodging. In the present study, an effort was made to induce semi dwarfism coupled with high yield in these genotypes retaining the complex tolerance. Dry seeds of these varieties were subjected to both physical mutagen (gamma rays 200, 300, 400 and 500Gy) and chemical mutagen treatment (0.5%, 1% and 2% of Ethyl Methane Sulphonate at varying exposure periods of 8h, 16h and 24h). Reduced germination percentage was noticed in all the treatments. Only 25% plants of VTL-3 irradiated with 400 Gy dose of gamma rays produced fertile seeds and 28% in VTL-4. Even in the fertile plants the seed fertility varied greatly (0.5 to 82.4%). The induction of 100% sterility in more than 75% plants of 400 Gy irradiated treatments compared to the maximum of 7% sterility in the untreated control indicated the high mutagenic potency of gamma irradiation in pokkali rice. Fifty eight semi dwarf mutants with significant reduction in plant height could be selected from the M2 generation of 400 Gy irradiated doze of VTL-3. The height of the selected plants varied from 82 cm to 120cm chemical mutagen treatment was not effective in inducing semidwarfism. More than 70% of the selected mutants showed stability for reduced plant height. The segregation data suggested that most of the mutant lines had single recessive mutations with the exception of few lines. The yield of the stable mutants were evaluated in an Initial Evaluation Trial and observed that some of the mutants had the potential to produce about double the yield (10 tons/ha) of its parent VTL-3 (5 tons/ha). (author)

  13. Heterosis and inbreeding depression for panicle characters in crosses involving induced mutants of aromatic rice

    Twelve crosses of aromatic rice utilizing four γ-ray induced mutants 88-8-3 and 33-9-15 of Tulaipanja and 124-17-4 and 21-6-1 of Gobindabhog and three basmati varieties were evaluated for heterosis and inbreeding depression for different panicle characters. All the hybrids except the two hybrids of 124-17-4 with Pakistan Basmati and Pusa Basmati I manifested significantly positive heterosis for grain yield panicle-1. High magnitude of heterosis coupled with positive inbreeding depression for panicle length, secondary branches panicle-1, spikelet number panicle-1, panicle weight and grain yield panicle-1 in several crosses indicating the presence of nonadditive gene action. The results indicate the scope of exploiting heterosis in aromatic rice. (author)

  14. Arsenic accumulation and phosphorus status in two rice (Oryza sativa L.) cultivars surveyed from fields in South China

    Lu Ying [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Dong, Fei [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); Deacon, Claire [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Chen Huojun [College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642 (China); Raab, Andrea [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Meharg, Andrew A., E-mail: a.meharg@abdn.ac.u [School of Biological Science, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom)

    2010-05-15

    The consumption of paddy rice (Oryza sativa L.) is a major inorganic arsenic exposure pathway in S.E. Asia. A multi-location survey was undertaken in Guangdong Province, South China to assess arsenic accumulation and speciation in 2 rice cultivars, one an Indica and the other a hybrid Indica. The results showed that arsenic concentrations in rice tissue increased in the order grain < husk < straw < root. Rice grain arsenic content of 2 rice cultivars was significant different and correlated with phosphorus concentration and molar ratio of P/As in shoot, being higher for the Indica cultivar than for the hybrid Indica, which suggests altering shoot phosphorus status as a promising route for breeding rice cultivars with reduced grain arsenic. Speciation of grain arsenic, performed using HPLC-ICP-MS, identified inorganic arsenic as the dominant arsenic species present in the rice grain. - Altering rice shoot phosphorus status is a promising route for breeding rice cultivars with reduced grain arsenic.

  15. Study of Genetics and Embryology of Polyembryonic Mutant of Autotetraploid Rice Induced by N+ Beam Implantation

    Dai, Ximei; Huang, Qunce; Li, Guoping; Hu, Xiuming; Qin, Guangyong; Yu, Zengliang

    2006-11-01

    In the present study autotetraploid rice IR36-4X was treated by an ion implantation technique with nitrogen ion beams. A polyembryonic mutant (named IR36-Shuang) was identified in the M2 generation. The mutant line and its offspring were systematically investigated in regard to their major agronomic properties and the rate of polyembryonic seedling in the M3-M6 generation. The abnormal phenomena in the embryo sac development and the cytological mechanism of the initiation of additional embryo in IR36-Shuang were observed by Laser Scanning Confocal Microscopy. The results were as follows. 1) The plant height, the panicle length and 1000 grain weight of IR36-Shuang were lower than that of its control by 35.41%, 5.08% and 15.72% respectively, Moreover, the setting percentage decreased 12.39% compared with that in normal IR36-4X plants. 2) The polyembryonic trait of IR36-Shuang was genetically stable and the frequency of the polyembryonic seedlings in the IR36-Shuang line was also relatively stable. 3) The rate of abnormal embryo sacs in IR36-Shuang was significantly higher than that in the control IR36-4X. 4) The additional embryo in IR36-Shuang might arise from the double set of embryo sacs in a single ovary, antipodal cells or endosperm cells. These results suggest that IR36-Shuang is a polyembryonic mutant and a new apomixis rice line induced by low energy ion implantation. The prospects for the application in production of the IR36-Shuang line are also discussed. The present study may provide a basis for future investigations of apomixis rice breeding via the ion implantation biotechnology.

  16. Physical and chemical mutagenesis of early mutant of indica restorers in ''WA'' (wild abortion) hybrid rice system and genetic analysis of mutants in heterosis utilization

    The four indica restorers in the wild abortion hybrid rice system were treated with physical and chemical mutagens, and the mutation frequency in the M2 generation and the correlation between the heading date of the mutants and other characters were investigated

  17. Ospapst1, a useful mutant for identifying seed purity and authenticity in hybrid rice

    Lv, Qundan; Xu, Jiming; Wu, Ping

    2013-01-01

    The stability and completeness of male sterility is still a challenge in some male sterile rice lines, especially those of photoperiod/thermo-sensitive genic male sterility (P/TGMS). Leaf color marker is a widely practiced approach to reduce the impact of self-pollinated seeds of male sterile lines. The papst1 is a leaf color mutant. The newly emerged leaves of papst1 are chlorosis and have an impaired photosynthesis. But the other agronomic traits, such as germination rate, duration of matur...

  18. A Lactobacillus mutant capable of accumulating long-chain polyphosphates that enhance intestinal barrier function.

    Saiki, Asako; Ishida, Yasuaki; Segawa, Shuichi; Hirota, Ryuichi; Nakamura, Takeshi; Kuroda, Akio

    2016-05-01

    Inorganic polyphosphate (polyP) was previously identified as a probiotic-derived substance that enhances intestinal barrier function. PolyP-accumulating bacteria are expected to have beneficial effects on the human gastrointestinal tract. In this study, we selected Lactobacillus paracasei JCM 1163 as a strain with the potential to accumulate polyP, because among the probiotic bacteria stored in our laboratory, it had the largest amount of polyP. The chain length of polyP accumulated in L. paracasei JCM 1163 was approximately 700 phosphate (Pi) residues. L. paracasei JCM 1163 accumulated polyP when Pi was added to Pi-starved cells. We further improved the ability of L. paracasei JCM 1163 to accumulate polyP by nitrosoguanidine mutagenesis. The mutant accumulated polyP at a level of 1500 nmol/mg protein-approximately 190 times that of the wild-type strain. PolyP extracted from the L. paracasei JCM 1163 significantly suppressed the oxidant-induced intestinal permeability in mouse small intestine. In conclusion, we have succeeded in breeding the polyP-accumulating Lactobacillus mutant that is expected to enhance intestinal barrier function. PMID:26966939

  19. Identification of the Second Mutation of BADH2 Gene Derived from Rice Mutant Lines Induced by Gamma Rays

    I. Ishak

    2016-04-01

    Full Text Available The BADH2 gene acts as suppressor of 2-acetyl-1-pyrolline (2AP biosynthesis in plants. 2AP is the volatile compound which provides fragrance in rice. Biosynthesis of 2AP occurs when BADH2 loses its function as suppressor gene. Aromatic rice cultivars naturally incur mutation of BADH2 gene at 8 bp. In this experiment, aromatic mutant rice lines derived from irradiation of Sintanur cultivar by gamma rays with dose of 100 Gy were studied in molecular level. These mutant lines were characterized at the M10 plantgeneration under the assumption that genetically these aromatic mutant rice lines were homozygotic. Several primers related to aroma in rice have been used for polymerase chain reaction (PCR in a thermal cycler instrument. Gel electrophoreses were carried out using 1.5% agarose in TAE buffer. DNA fragments at 254 bp and 355 bp (base pair were taken and amplified by primer for nucleotide sequencing of these fragments. Molecular identification and characterization after electrophoresis showed that the mutant line from AR1020 can be differentiated from AR.1080 at 254 bp. Nucleotide sequence data from of these DNA fragments showed that point mutations (deletions and substitutions occurred at the BADH2 gene in exon 7; those are called second mutation and were caused by gamma rays effects. The Sintanur variety was used as check cultivar and its DNA sequence was compared to that of the AR.1020 mutant line. The results from both DNA sequences (from cv. Sintanur and AR.1020 derived from fragments at 254 bp show that point mutations occurred within exon 7 and earlier stop codon occurred in the AR.1020 mutant rice line. Further, the use of EA primer in PCR resulted in detection of deletion and substitution of nucleotides in the AR.1020 mutant line.

  20. Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar

    Pengjie Hu; Younan Ouyang; Longhua Wu; Libo Shen; Yongming Luo; Peter Christie

    2015-01-01

    Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd.In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend.Compared to arsenate,there were more marked changes in the arsenite concentrations in the soil solution as water management shifted,and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil.In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions.Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha.The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment.Thus,water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice.Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd.

  1. Uptake,Subcellular Distribution,and Chemical Forms of Cadmium in Wild-Type and Mutant Rice

    HE Jun-Yu; ZHU Cheng; REN Yan-Fang; YAN Yu-Ping; CHENG Chang; JIANG De-An; SUN Zong-Xiu

    2008-01-01

    Wild-type (Zhonghua 11) and mutant rice (Oryza sativa L.) plants were used to investigate the effect of cadmium (Cd) application on biomass production,to characterize the influx of Cd from roots to shoots,and to determine the form,content,and subcellular distribution of Cd in the roots,leaf sheaths,and leaves of the rice plants.Seedlings were cultivated in a nutrient solution and were treated with 0.5 mmol L-1 of Cd2+ for 14 d.The sensitivity of rice plants to Cd toxicity was tested by studying the changes in biomass production and by observing the onset of toxicity symptoms in the plants.Both the wild-type and mutant rice plants developed symptoms of Cd stress.In addition,Cd application significantly (P ≤ 0.01) decreased dry matter production of roots,leaf sheaths,and leaves of both types,especially the mutant.The Cd content in roots of the mutant was significantly (P≤0.05) higher than that of the wild-type rice.However,there was no significant difference in the Cd content of roots,leaf sheaths,and leaves between the wild-type and mutant rice.Most of the Cd was bound to the cell wall of the roots,leaf sheaths,and leaves,and the mutant had greater Cd content in cell organelles than the wild type.The uneven subcellular distribution could be responsible for the Cd sensitivity of the mutant rice.Furthermore,different chemical forms of Cd were found to occur in the roots,leaf sheaths,and leaves of both types of rice plants.Ethanol-,water-,and NaCl-extractable Cd had greater toxicity than the other forms of Cd and induced stunted growth and chlorosls in the plants.The high Cd content of the toxic forms of Cd in the cell organelles could seriously damage the cells and the metabolic processes in mutant rice plants.

  2. Lack of Globulin Synthesis during Seed Development Alters Accumulation of Seed Storage Proteins in Rice

    Hye-Jung Lee

    2015-06-01

    Full Text Available The major seed storage proteins (SSPs in rice seeds have been classified into three types, glutelins, prolamins, and globulin, and the proportion of each SSP varies. It has been shown in rice mutants that when either glutelins or prolamins are defective, the expression of another type of SSP is promoted to counterbalance the deficit. However, we observed reduced abundances of glutelins and prolamins in dry seeds of a globulin-deficient rice mutant (Glb-RNAi, which was generated with RNA interference (RNAi-induced suppression of globulin expression. The expression of the prolamin and glutelin subfamily genes was reduced in the immature seeds of Glb-RNAi lines compared with those in wild type. A proteomic analysis of Glb-RNAi seeds showed that the reductions in glutelin and prolamin were conserved at the protein level. The decreased pattern in glutelin was also significant in the presence of a reductant, suggesting that the polymerization of the glutelin proteins via intramolecular disulfide bonds could be interrupted in Glb-RNAi seeds. We also observed aberrant and loosely packed structures in the storage organelles of Glb-RNAi seeds, which may be attributable to the reductions in SSPs. In this study, we evaluated the role of rice globulin in seed development, showing that a deficiency in globulin could comprehensively reduce the expression of other SSPs.

  3. Mutation Breeding and Selection for Phenotypic Mutants in Standard Rice Varieties by Ion Beam

    Full text: Effects of 80 keV ion beam (1016 ion/cm2 on mutations of RD6 and Sanpatong 1 rice varieties were studied in 2006. In order to obtain the phenotypic mutants, each variety was sown in the laboratory and under field conditions at Maejo University in 2007 dry season. Seed germination noticeably declined. For RD6, only 45.1% germinated in the laboratory, and 18.1% were established under the field condition. Similarly, 62.3% of Sanpatong 1 germinated in the laboratory and 31.4% established in the field. No phenotypic mutants were observed in the first generation (M1). The M2 seeds were harvested separately from 3 panicles of each M plant in RD6 and Sanpatong1, totaling 810 and 1,878 lines, respectively. In 2007 rainy season, they were planted on a panicle to row basis. It was found that more phenotypic mutants were observed in the M2 for Sanpatong 1 than for RD6. The mutant characters included dwarf plants, early maturity, male sterility and larger panicle sizes. As a result, about 420 within line selections were collected and the M3 seeds were harvested for further field condition and gene markers evaluations

  4. Water-deficit tolerant classification in mutant lines of indica rice

    Suriyan Cha-um

    2012-04-01

    Full Text Available Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control as water deficit sensitive, using Ward's method.

  5. Genetic analysis of the induced mutants of rice resistant to bacterial leaf blight

    Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M3 or M4 lines derived from selected resistant M2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

  6. Analysis of SSLP and Soluble Protein Contents in Leaves of Mutants Induced by High Pressure in Rice (Oryza sativa)

    HE Xiu-ying; XU Shi-ping; LIAO Yao-ping; MAO Xing-xue; WENG Ke-nan; CHEN Zhao-ming; CHEN Yue-han; XIAO Wan-sheng

    2004-01-01

    Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatellite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants,and the contents were significantly lower than those of the original variety.

  7. Soil removal as a decontamination practice and radiocesium accumulation in tadpoles in rice paddies at Fukushima

    We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean 134Cs and 137Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0–5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. - Highlights: • Surface soil removal in a rice paddy reduced the radiocesium concentration in soil. • The radiocesium concentration in tadpoles decreased following decontamination. • Radiocesium levels in soil increased at 1 year following decontamination practice. • Reduction of radiocesium of soil can propagate to biota in rice paddies. - Decontamination practice reduced radiocesium concentrations in both soil and tadpoles that suggests reduction of radiocesium of soil can propagate to biota in rice paddies

  8. Comparative metabolomic analysis of wild type and mads3 mutant rice anthers

    Guorun Qu; Sheng Quan; Palash Mondol; Jie Xu; Dabing Zhang; Jianxin Shi

    2014-01-01

    Rice (Oryza sativa L.) MADS3 transcription factor regulates the homeostasis of reactive oxygen species (ROS) during late anther development, and one MADS3 mutant, mads3-4, has defective anther wal s, aborted microspores and complete male sterility. Here, we report the untargeted metabolomic analysis of both wild type and mads3-4 mature anthers. Mutation of MADS3 led to an unbalanced redox status and caused oxidative stress that damages lipid, protein, and DNA. To cope with oxidative stress in mads3-4 anthers, soluble sugars were mobilized and carbohydrate metabolism was shifted to amino acid and nucleic acid metabolism to provide substrates for the biosynthesis of antioxidant proteins and the repair of DNA. Mutation of MADS3 also affected other aspects of rice anther development such as secondary metabolites associated with cuticle, cellwal , and auxin metabolism. Many of the discovered metabolic changes in mads3-4 anthers were corroborated with changes of expression levels of correspond-ing metabolic pathway genes. Altogether, this comparative metabolomic analysis indicated that MADS3 gene affects rice anther development far beyond the ROS homeostasis regulation.

  9. Development and character observation of autotetraploid polyembryonic mutant rice induced by ion beam implantation

    Autotetraploid rice IR36-4X was treated with ion implantation of low energy nitrogen ion beams and a polyembryonic seedling mutant IR36-Shuang was identified in M2 generation. The major agronomic characters, morphology and the genetic stability of polyembryonic seedling of the mutant line were systematically investigated. The results are as follows. The agronomic characters of IR36-Shuang were obvious different with its parent IR36-4X. The plant height, panicle length, 1000 grain weight and the setting rate of the IR36-Shuang were lower than that of its parent by 35.41%, 5.08%, 15.72% and 12.39%, respectively. The morphology of polyembryonic rice IR36-Shuang could be differentiated into 2 types: uncomplete twin seedlings and complete twin seedlings. There were 2 types in uncomplete twin seedlings, i.e. twin seedlings with single plumule axis and single radicle and twin seedlings with single radicle and twin plumule axis. The complete twin seedlings also included 2 types, i.e. normal and abnormal twin seedlings. In IR36-Shuang materials, the rate of twin seedlings with single radicle and single plumule axis was higher than that in other types. The several generations observation showed that the polyembryonic trait was inherited and stable. (authors)

  10. Vascular defense responses in rice: peroxidase accumulation in xylem parenchyma cells and xylem wall thickening

    Hilaire, E.; Young, S. A.; Willard, L. H.; McGee, J. D.; Sweat, T.; Chittoor, J. M.; Guikema, J. A.; Leach, J. E.

    2001-01-01

    The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae is a vascular pathogen that elicits a defensive response through interaction with metabolically active rice cells. In leaves of 12-day-old rice seedlings, the exposed pit membrane separating the xylem lumen from the associated parenchyma cells allows contact with bacterial cells. During resistant responses, the xylem secondary walls thicken within 48 h and the pit diameter decreases, effectively reducing the area of pit membrane exposed for access by bacteria. In susceptible interactions and mock-inoculated controls, the xylem walls do not thicken within 48 h. Xylem secondary wall thickening is developmental and, in untreated 65-day-old rice plants, the size of the pit also is reduced. Activity and accumulation of a secreted cationic peroxidase, PO-C1, were previously shown to increase in xylem vessel walls and lumen. Peptide-specific antibodies and immunogold-labeling were used to demonstrate that PO-C1 is produced in the xylem parenchyma and secreted to the xylem lumen and walls. The timing of the accumulation is consistent with vessel secondary wall thickening. The PO-C1 gene is distinct but shares a high level of similarity with previously cloned pathogen-induced peroxidases in rice. PO-C1 gene expression was induced as early as 12 h during resistant interactions and peaked between 18 and 24 h after inoculation. Expression during susceptible interactions was lower than that observed in resistant interactions and was undetectable after infiltration with water, after mechanical wounding, or in mature leaves. These data are consistent with a role for vessel secondary wall thickening and peroxidase PO-C1 accumulation in the defense response in rice to X. oryzae pv. oryzae.

  11. Drought resistant rice mutants and their feasibility for planting in semi-arid and desert areas

    A mutation breeding programme on rice was started in 1978 with the aim of increasing the protein content of the grain; later, in 1982, the programme progressed to selecting for stress resistance (water and salinity). The programme included: collection of available germplasm for rice; irradiation of seeds with 100-200 Gy of 60Co gamma rays; crosses, backcrosses and selection, taking into consideration the yearly reduction in irrigation water. This started at the normal rate for local varieties in Egypt, i.e. 21,000 m3/ha, but the rate has been reduced to 10,000 m3/ha over the past 4 years. This programme has led to the selection of 32 drought resistant rice mutants. Planting was carried out during the 1991 season in 3 m x 3 m plots with four replications on clay and sandy loam soil. In 1992, planting was carried out in the same way, but only on sandy loam soil (62.2% sand, 13.2% clay and 24.6% silt). The results showed that Giza 171 and Giza 181 produced a very poor yield, i.e. 181 and 272 kg/ha, respectively. On the other hand, the yields of the four drought resistant mutant lines, under the same conditions (sandy loam soil and 8000-10,000 m3/ha of irrigation water), were 8488, 9063, 10,755 and 11,400 kg/ha of paddy for Hegazi-10, Hegazi-Fo, Hegazi-Go and Hegazi-7, respectively. 3 refs, 1 tab

  12. Dry matter and nitrogen accumulation in T. durum cv. hamari and some of its mutant lines

    Under a low N level (N0) the parental lines ahd a lower average mean rate for dry matter accumulation, but a slightly longer duration than that of the mutants. However, under a high N level (N1) the mutant lines showed a 4% reduction in seed weight compared with the parental lines. No significant differences were found among the lines in their rate of N accumulation, suggesting that carbohydrates rather than nitrogenous compounds are the crucial determinant of N concentration in the seeds. It is inferred that in the same line it may be possible to achieve either a higher grain yield with a lower protein percentage or a lower yield with a correspondingly higher protein percentage. (author). 4 refs, 2 tabs

  13. Dry matter and nitrogen accumulation in T. durum CV. hamari and some of its mutant lines

    Under a low N level (N0) the parental lines had a lower average mean rate for dry matter accumulation, but a slightly longer duration than that of the mutants. However, under a high N level (N1) the mutant lines showed a 4% reduction in seed weight compared with the parental lines. No significant differences were found among the lines in their rate of N accumulation, suggesting that carbohydrates rather than nitrogenous compounds are the crucial determinant of N concentration in the seeds. It is inferred that in the same line it may be possible to achieve either a higher grain yield with a lower protein percentage or a lower yield with a correspondingly higher protein percentage. (author). 4 refs., 2 tabs

  14. Mapping of a rice thermosensitive genic male sterility gene from a TGMS mutant line

    Vu Duc Quang; Nguyen Van Dong; Pham Ngoc Luong; Tran Duy Quy [Argicultural Genetics Institute, Hanoi (Viet Nam); Nguyen, Henry T. [Texas Tech Univ., Department of Plant and Soil Science, Lubbock TX (United States)

    2001-03-01

    At the Agricultural Genetics Institute (AGI), Hanoi, Vietnam, a number of thermo-sensitive genic male sterility (TGMS) homozygous rice lines have been developed by means of experimental mutagenesis followed by anther culture techniques. One of them (TGMS-1 indica mutant line) was used in this research. The critical temperature (at the period from pollen mother cell formation to the beginning of meiotic division) for TGMS-1 sterility was 24-25degC, below which the plants were fertile and above which the plants became sterile. Segregation analysis showed that the TGMS trait of the TGMS-1 mutant line was controlled by a single recessive gene. An F{sub 2} mapping population from a cross between TGMS-1 mutant line and CH1 (a fertile indica line) was developed for tagging and mapping the TGMS gene. From survey of 200 AFLP primer combinations in a bulked segregant analysis, 4 AFLP markers (E2/M5-200, E3/M16-400, E5/M12-600 and E5/M12-200) linked to TGMS-1 gene were identified and cloned. All except E2/M5-200 were found to be low-copy number sequences. The marker E5/M12-600 showed polymorphism in RFLP analysis and was closely linked to the TGMS gene at a distance of 3.3cM. This marker was subsequently mapped on chromosome 2 using doubled-haploid mapping populations derived from the crosses IR64xAzucena and CT9993xIR62666. Linkage of microsatellite marker RM27 with the TGMS gene further confirmed its location on chromosome 2. The closest marker, E5/M12-600, was sequenced so that a PCR marker can be developed for the use in marker-assisted breeding. The application of TGMS genes to the commercial two-line hybrid rice breeding system was discussed. (author)

  15. Mapping of a rice thermosensitive genic male sterility gene from a TGMS mutant line

    At the Agricultural Genetics Institute (AGI), Hanoi, Vietnam, a number of thermo-sensitive genic male sterility (TGMS) homozygous rice lines have been developed by means of experimental mutagenesis followed by anther culture techniques. One of them (TGMS-1 indica mutant line) was used in this research. The critical temperature (at the period from pollen mother cell formation to the beginning of meiotic division) for TGMS-1 sterility was 24-25degC, below which the plants were fertile and above which the plants became sterile. Segregation analysis showed that the TGMS trait of the TGMS-1 mutant line was controlled by a single recessive gene. An F2 mapping population from a cross between TGMS-1 mutant line and CH1 (a fertile indica line) was developed for tagging and mapping the TGMS gene. From survey of 200 AFLP primer combinations in a bulked segregant analysis, 4 AFLP markers (E2/M5-200, E3/M16-400, E5/M12-600 and E5/M12-200) linked to TGMS-1 gene were identified and cloned. All except E2/M5-200 were found to be low-copy number sequences. The marker E5/M12-600 showed polymorphism in RFLP analysis and was closely linked to the TGMS gene at a distance of 3.3cM. This marker was subsequently mapped on chromosome 2 using doubled-haploid mapping populations derived from the crosses IR64xAzucena and CT9993xIR62666. Linkage of microsatellite marker RM27 with the TGMS gene further confirmed its location on chromosome 2. The closest marker, E5/M12-600, was sequenced so that a PCR marker can be developed for the use in marker-assisted breeding. The application of TGMS genes to the commercial two-line hybrid rice breeding system was discussed. (author)

  16. The assimilation of spectral sensing and the WOFOST model for the dynamic simulation of cadmium accumulation in rice tissues

    Wu, Ling; Liu, Xiangnan; Wang, Ping; Zhou, Botian; Liu, Meiling; Li, Xuqing

    2013-12-01

    The accurate detection of heavy metal-induced stress on crop growth is important for food security and agricultural, ecological and environmental protection. Spectral sensing offers an efficient and undamaged observation tool to monitor soil and vegetation contamination. This study proposed a methodology for dynamically estimating the total cadmium (Cd) accumulation in rice tissues by assimilating spectral information into WOFOST (World Food Study) model. Based on the differences among ground hyperspectral data of rice in three experiments fields under different Cd concentration levels, the spectral indices MCARI1, NREP and RH were selected to reflect the rice stress condition and dry matter production of rice. With assimilating these sensitive spectral indices into the WOFOST + PROSPECT + SAIL model to optimize the Cd pollution stress factor fwi, the dynamic dry matter production processes of rice were adjusted. Based on the relation between dry matter production and Cd accumulation, we dynamically simulating the Cd accumulation in rice tissues. The results showed that the method performed well in dynamically estimating the total amount of Cd accumulation in rice tissues with R2 over 85%. This study suggests that the proposed method of integrating the spectral information and the crop growth model could successfully dynamically simulate the Cd accumulation in rice tissues.

  17. Effect of introduction method on accumulation of 89Sr in the rice plant

    The isotope tracer technique was used to explore the effect of different introduction method on accumulation of radioactive strontium in the rice plant. The results showed that concentration of 89Sr decreased with time in the rice plant, paddy water and paddy soil for spray and fall treatments. It shows an individual exponential function. For irrigation treatment, change of concentration of 89Sr in the rice plant, paddy water and paddy soil was more complicated. The relationship of concentration and time was described as multinomial exponential function. The concentration distribution of 89Sr in the paddy soil was identical among three treatments and showed an individual exponential declining with depth. CF value of 89Sr was CFwater>CFsoil for each treatment

  18. Characterization and Fine Mapping of a Novel Rice Albino Mutant low temperature albino 1

    Yu Peng; Sheng Teng; Yi Zhang; Jun Lv; Jianhui Zhang; Ping Li; Xiaoliang Shi; Yufeng Wang; Honglei Zhang; Zuhua He

    2012-01-01

    Albino mutants are useful genetic resource for studying chlorophyll biosynthesis and chloroplast development and cloning genes involved in these processes in plants.Here we report a novel rice mutant low temperature albino I (ltal) that showed albino leaves before 4-leaf stage when grown under temperature lower than 20℃,but developed normal green leaves under temperature higher than 24℃ or similar morphological phenotypes in dark as did the wild-type (WT).Our analysis showed that the contents of chlorophylls and chlorophyll precursors were remarkably decreased in the ltal mutant under low temperature compared to WT.Transmission electron microscope observation revealed that chloroplasts were defectively developed in the albino ltal leaves,which lacked of well-stacked granum and contained less stroma lamellae.These results suggested that the ltal mutation may delay the light-induced thylakoid assembly under low temperature.Genetic analysis indicated that the albino phenotype was controlled by a single recessive locus.Through map-based approach,we finally located the Ltal gene to a region of 40.3 kb on the short arm of chromosome 11.There are 8 predicted open reading frames (ORFs) in this region and two of them were deleted in ltal genome compared with the WT genome.The further characterization of the Ltal gene would provide a good approach to uncover the novel molecular mechanisms involved in chloroplast development under low temperature stress.

  19. Structural characterization of a mixed-linkage glucan deficient mutant reveals alteration in cellulose microfibril orientation in rice coleoptile mesophyll cell walls

    Andreia Michelle Smith-Moritz

    2015-08-01

    Full Text Available The CELLULOSE SYNTHASE-LIKE F6 (CslF6 gene was previously shown to mediate the biosynthesis of mixed-linkage glucan (MLG, a cell wall polysaccharide that is hypothesized to be a tightly associated with cellulose and also have a role in cell expansion in the primary cell wall of young seedlings in grass species. We have recently shown that loss-of-function cslf6 rice mutants do not accumulate MLG in most vegetative tissues. Despite the absence of a structurally important polymer, MLG, these mutants are unexpectedly viable and only show a moderate growth compromise compared to wild type. Therefore these mutants are ideal biological systems to test the current grass cell wall model. In order to gain a better understanding of the role of MLG in the primary wall, we performed in-depth compositional and structural analyses of the cell walls of three day-old rice seedlings using various biochemical and novel microspectroscopic approaches. We found that cellulose content as well as matrix polysaccharide composition was not significantly altered in the MLG deficient mutant. However, we observed a significant change in cellulose microfibril bundle organization in mesophyll cell walls of the cslf6 mutant. Using synchrotron source Fourier Transform Mid-Infrared Spectromicroscopy for high-resolution imaging, we determined that the bonds associated with cellulose and arabinoxylan, another major component of the primary cell was of grasses, were in a lower energy configuration compared to wild type, suggesting a slightly weaker primary wall in MLG deficient mesophyll cells. Taken together, these results suggest that MLG may influence cellulose deposition in mesophyll cell walls without significantly affecting anisotropic growth thus challenging MLG importance in cell wall expansion.

  20. Mutant p53 accumulates in cycling and proliferating cells in the normal tissues of p53 R172H mutant mice.

    Goh, Amanda M; Xue, Yuezhen; Leushacke, Marc; Li, Ling; Wong, Julin S; Chiam, Poh Cheang; Rahmat, Siti Aishah Binte; Mann, Michael B; Mann, Karen M; Barker, Nick; Lozano, Guillermina; Terzian, Tamara; Lane, David P

    2015-07-20

    The tumour suppressor p53 is regulated primarily at the protein level. In normal tissues its levels are maintained at a very low level by the action of specific E3 ligases and the ubiquitin proteosome pathway. The mutant p53 protein contributes to transformation, metastasis and drug resistance. High levels of mutant p53 can be found in tumours and the accumulation of mutant p53 has previously been reported in pathologically normal cells in human skin. We show for the first time that similarly elevated levels of mutant p53 can be detected in apparently normal cells in a mutant p53 knock-in mouse model. In fact, in the small intestine, mutant p53 spontaneously accumulates in a manner dependent on gene dosage and cell type. Mutant p53 protein is regulated similarly to wild type p53, which can accumulate rapidly after induction by ionising radiation or Mdm2 inhibitors, however, the clearance of mutant p53 protein is much slower than wild type p53. The accumulation of the protein in the murine small intestine is limited to the cycling, crypt base columnar cells and proliferative zone and is lost as the cells differentiate and exit the cell cycle. Loss of Mdm2 results in even higher levels of p53 expression but p53 is still restricted to proliferating cells in the small intestine. Therefore, the small intestine of these p53 mutant mice is an experimental system in which we can dissect the molecular pathways leading to p53 accumulation, which has important implications for cancer prevention and therapy. PMID:26255629

  1. A heavy metal P-type ATPase OsHMA4 prevents copper accumulation in rice grain

    As one of the most important staple crops, rice not only provides more than one fifth of daily calories for half of the world’s human population but is also a major source of mineral nutrients. However, little is known about the genetic basis of mineral nutrient accumulation in rice grain such as co...

  2. Characterization and Genetic Analysis of Rumpled and Twisted Leaf Mutant (rt/1) in Rice

    FANG Yun-xia; SONG Xiu-juan; PENG You-lin; DONG Guo-jun; Guo Long-biao; ZENG Da-li; ZHANG Guang-heng; YAN Hong-lan; QIAN Qian

    2011-01-01

    A rumpled and twisted leaf 1 (rt/1) mutant was generated from a japonica cultivar Nipponbare by ethyl methanesulfonate treatment,which was characterized as rumpled and twisted leaf at the seedling stage.The F2 populations were constructed by crossing with indica cultivars TN1 and Zhefu 802,respectively.Genetic analysis demonstrated that the phenotype was controlled by a single recessive nuclear gene.The closely linked simple sequence repeat (SSR) marker RM1155 was obtained from bulked segregant analysis.Subsequently,sequence tagged site (STS) markers were developed using the published rice genome sequence.Finally,RTL1 was located between an STS marker T1591 and an SSR marker RM1359,at the distances of 0.48 cM and 0.96 cM,respectively.These results will facilitate the cloning of the target gene in further studies.

  3. Isozymes variability in rice mutants induced by fast neutrons and gamma rays

    The isozyme variability of a group of rice mutants induced through gamma and fast neutron (14 MeV) irradiation was studied. Polymorphisms were detected using esterase, peroxidase, polyphenol oxidase and alcohol dehydrogenase systems. The mean value of genetic similarity among the different cultivars, which arose from isozymes, was 0.75. The dendrogram was constructed based on genetic similarity matrices, designed with isozyme data using the unweighed pair group method arithmetic average (UPGMA) method. The efficiency of the UPGMA model for the estimation of genetic relationship among cultivars was supported by cophenetic correlation coefficients. Such values indicate that the distortion degree for the estimated similarities was minimal. It was found that both gamma rays and fast neutrons generated a wide range of variability which can be detected by means of isozyme patterns, even in closely related cultivars. (author)

  4. Vermicompost humic acids modulate the accumulation and metabolism of ROS in rice plants.

    García, Andrés Calderín; Santos, Leandro Azevedo; de Souza, Luiz Gilberto Ambrósio; Tavares, Orlando Carlos Huertas; Zonta, Everaldo; Gomes, Ernane Tarcisio Martins; García-Mina, José Maria; Berbara, Ricardo Luis Louro

    2016-03-15

    This work aims to determine the reactive oxygen species (ROS) accumulation, gene expression, anti-oxidant enzyme activity, and derived effects on membrane lipid peroxidation and certain stress markers (proline and malondialdehyde-MDA) in the roots of unstressed and PEG-stressed rice plants associated with vermicompost humic acid (VCHA) application. The results show that the application of VCHA to the roots of unstressed rice plants caused a slight but significant increase in root ROS accumulation and the gene expression and activity of the major anti-oxidant enzymes (superoxide dismutase and peroxidase). This action did not have negative effects on root development, and an increase in both root growth and root proliferation occurred. However, the root proline and MDA concentrations and the root permeability results indicate the development of a type of mild stress associated with VCHA application. When VCHA was applied to PEG-stressed plants, a clear alleviation of the inhibition in root development linked to PEG-mediated osmotic stress was observed. This was associated with a reduction in root ROS production and anti-oxidant enzymatic activity caused by osmotic stress. This alleviation of stress caused by VCHA was also reflected as a reduction in the PEG-mediated concentration of MDA in the root as well as root permeability. In summary, the beneficial action of VCHA on the root development of unstressed or PEG-stressed rice plants clearly involves the modulation of ROS accumulation in roots. PMID:26851887

  5. PIAS1 Regulates Mutant Huntingtin Accumulation and Huntington's Disease-Associated Phenotypes In Vivo.

    Ochaba, Joseph; Monteys, Alex Mas; O'Rourke, Jacqueline G; Reidling, Jack C; Steffan, Joan S; Davidson, Beverly L; Thompson, Leslie M

    2016-05-01

    The disruption of protein quality control networks is central to pathology in Huntington's disease (HD) and other neurodegenerative disorders. The aberrant accumulation of insoluble high-molecular-weight protein complexes containing the Huntingtin (HTT) protein and SUMOylated protein corresponds to disease manifestation. We previously identified an HTT-selective E3 SUMO ligase, PIAS1, that regulates HTT accumulation and SUMO modification in cells. Here we investigated whether PIAS1 modulation in neurons alters HD-associated phenotypes in vivo. Instrastriatal injection of a PIAS1-directed miRNA significantly improved behavioral phenotypes in rapidly progressing mutant HTT (mHTT) fragment R6/2 mice. PIAS1 reduction prevented the accumulation of mHTT and SUMO- and ubiquitin-modified proteins, increased synaptophysin levels, and normalized key inflammatory markers. In contrast, PIAS1 overexpression exacerbated mHTT-associated phenotypes and aberrant protein accumulation. These results confirm the association between aberrant accumulation of expanded polyglutamine-dependent insoluble protein species and pathogenesis, and they link phenotypic benefit to reduction of these species through PIAS1 modulation. PMID:27146268

  6. Prediction of methylmercury accumulation in rice grains by chemical extraction methods

    To explore the possibility of using chemical extraction methods to predict phytoavailability/bioaccumulation of soil-bound MeHg, MeHg extractions by three widely-used extractants (CaCl2, DTPA, and (NH4)2S2O3) were compared with MeHg accumulation in rice grains. Despite of variations in characteristics of different soils, MeHg extracted by (NH4)2S2O3 (highly affinitive to MeHg) correlated well with grain MeHg levels. Thus (NH4)2S2O3 extraction, solubilizing not only weakly-bound and but also strongly-bound MeHg, may provide a measure of ‘phytoavailable MeHg pool’ for rice plants. Besides, a better prediction of grain MeHg levels was obtained when growing condition of rice plants was also considered. However, MeHg extracted by CaCl2 or DTPA, possibly quantifying ‘exchangeable MeHg pool’ or ‘weakly-complexed MeHg pool’ in soils, may not indicate phytoavailable MeHg or predict grain MeHg levels. Our results provided the possibility of predicting MeHg phytoavailability/bioaccumulation by (NH4)2S2O3 extraction, which could be useful in screening soils for rice cultivation in contaminated areas. - Highlights: • MeHg extraction by (NH4)2S2O3 correlates well with its accumulation in rice grains. • MeHg extraction by (NH4)2S2O3 provides a measure of phytoavailable MeHg in soils. • Some strongly-bound MeHg could be desorbed from soils and available to rice plants. • MeHg extraction by CaCl2 or DTPA could not predict grain MeHg levels. - Methylmercury extraction from soils by (NH4)2S2O3 could possibly be used for predicting methylmercury phytoavailability and its bioaccumulation in rice grains

  7. The use of mutant stock for semi-dwarf plant type and early maturity as cross-breeding materials in rice (coordinated programme on semi-dwarf mutants for rice improvement in Asia and the Pacific Region - RCA)

    Development of semi-dwarf type varieties has led to a substantial yield increase in Thailand, where rice is cultivated on areas of about 8 million hectars. Of 19 recommended Thai rice varieties, 10 possess the DGWG gene which determines semi-dwarf character. This situation can create some problems in terms of genetic vulnerability towards pests, diseases and other adverse stresses. The authors found that susceptibility to disease and insect pests as well as poor grain quality are major drawbacks associated with the DGWG gene. With this background, the major project goal was to obtain, by mutation techniques, a new genetic source of semi-dwarfness. For this purpose 3 tall local Thai varieties (Leaung Awn 29, Niaw Sanpah Tawng and Khao Dawk Mali) with very good grain quality, were chosen as parent material. Using radiation techniques 2 glutinous and 7 non-glutinous semi-dwarf mutants were obtained. Results of agronomic trials indicated that the mutants from local varieties were more promising and higher yielding in comparison to introduced varieties from IRRI, Taiwan, China, France and the USA. The preliminary genetics analysis of these mutants indicated an allelic relationship to the DGWG gene. This result is very important for the rice breeding programme because it made available the semi-dwarf gene in a new genetic background - with desirable characteristics for cultivation in Thailand. These positive results stimulated efforts to obtain new semi-dwarf mutants from other local, lowland rice varieties such as Leaung Tawang and Leb Mue Nahng 111. 49 and 35 semi-dwarf mutants were already selected after irradiation and are now under agronomic evaluation

  8. Selection of rice mutants Oryza Sativa L. with tolerance to saline grounds

    A selection of rice mutants with tolerance to salinity, took place in the Escuela de Ciencias Agrarias de la Universidad Nacional de Heredia, in conditions of hothouse starting from a population of M2 segregative seed, coming from commercial seed radiated with Co 60 gamma rays. The studied segregatives were: Setesa-9, Experimental II and Experimental I. For making this selection, the seed M2 was planted in plastic trays with saline soil with electrical conductivity values from 8 to 10 mmhos/cm. In each case, non-radiated original seed was used as control. After 22 days the seedling germinated, an evaluation was made and it was seen that any of the controls had resisted to the saline stress, and only those segregatives resistent to salinity survived. These were the next ones: 9 individuals of Setesa, 10 of the Experimental II, and 9 of Experimental I. The index of selection obtained was: 3.6, 4.0 y 3.6 respectively. In a second phase of the experiment, the seedling selected as salinity resistant, were taken to the ground were they were developed for getting the M3 mutant seed tolerant to salinity. The plants were individually harvested in the ground and each one had a specific identification. Then, weight and number data, fertile grain and ineffectives of the M3 seed were taken. After, for corroborating the capacity of tolerance to salinity, M3 seed was planted in flowerpots with saline soil with a value of electrical conductivity between 8 and 10 mmhos/cm. After data were analyzed, it was proved that some rice mutants had a profit of even 28 grams for 1000 grams as: ExpI-17, ExpI-15, ExpI-08, ExpII-22, ExpII-08, ExpII-30 and Se-9-14, Se-9-39 and Se-9-10. Therefore, the methodology utilized showed being effective and efficient for the objectives of the work

  9. Accumulation and distribution of polycyclic aromatic hydrocarbons in rice (Oryza sativa)

    Various tissues of rice plants were sampled from a PAH contaminated site in Tianjin, China at different growth stages of the ripening period and analyzed for PAHs. PAHs were much higher in roots than in the exposed tissues. Grains and internodes accumulated much smaller amounts of PAHs than leaves, hulls or ear axes. No specific gradient trends along roots, stem, ear axes, and grains were observed, suggesting that systematic translocation among them is unlikely. Over the ripening period, PAH concentrations were increased in rice roots and decreased in most above-ground tissues. Significant correlations between PAH and lipid contents can only be observed during full mature stage. The spectra of individual PAH compounds in rice organs including roots were similar to those in air, rather than those in soil. There was also a significant correlation between bioconcentration factor (BCF, plant over air) and octanol/air partitioning coefficient (K oa). - PAHs in various tissues of rice plants from various growth stages were investigated

  10. The α-subunit of the rice heterotrimeric G protein, RGA1, regulates drought tolerance during the vegetative phase in the dwarf rice mutant d1.

    Ferrero-Serrano, Ángel; Assmann, Sarah M

    2016-05-01

    Essential in the Green Revolution was the development of high-yielding dwarf varieties of rice (Oryza sativa L.), but their selection was not based on responses to water limitation. We studied physiological responses to progressive drought of the dwarf rice mutant, d1, in which the RGA1 gene, which encodes the GTP-binding α-subunit of the heterotrimeric G protein, is non-functional. Wild-type (WT) plants cease net carbon fixation 11 days after water is withheld, while d1 plants maintain net photosynthesis for an additional week. During drought, d1 plants exhibit greater stomatal conductance than the WT, but both genotypes exhibit the same transpirational water loss per unit leaf area. This is explained by a smaller driving force for water loss in d1 owing to its lower leaf temperatures, consistent with its more erect architecture. As drought becomes more severe, WT plants show an accelerated decline in photosynthesis, which may be exacerbated by the higher leaf temperatures in the WT. We thus show how a rice mutant with dwarf and erect leaves has a decreased susceptibility to water stress. Accordingly, it may be useful to incorporate RGA1 mutation in breeding or biotechnological strategies for development of drought-resistant rice. PMID:27194741

  11. Biochemical characterization of 5-methyltryptophan resistant rice mutants through SDS-PAGE and 2-dimensional gel electrophoresis

    To increase the contents of specific amino acids in the rice (Oriza sativa L.) cv. Dongan, original variety (control), we developed 4 homologous 5- methyltryptophan (5MT) resistant rice M5 mutant lines via in vitro mutagenesis with gamma-ray. These mutant lines exhibited elevated amino acid content, in addition to an increased tolerance to 5MT inhibition. SDS-PAGE analysis was conducted to identify changes in total proteins and purified protein fractions based on their solubility properties between the control and 4 mutant lines. Significant differences in total protein fractions were detected at the molecular weight of about 26 kDa and 18 kDa between the control and 2 mutant lines. In the patterns of 4 solubility classes, enhanced polypeptides with high signal intensity were observed in mutant lines compared with that of the control. It was also interesting that the significant differences in prolamin band patterns between MRI were found at about 18 kDa and 16 kDa. Proteins produced in elevated amounts or de novo in response to 5MT were studied by comparing silver-stained two-dimensional gels of leaf proteins between the control and 4 5MT resistant lines. Five N-terminal sequences were obtained and the database was searched to tentatively identify them. Sequencing data of de novo or enhanced proteins in mutant lines demonstrate that the resistance for 5MT may be similar to mechanism to cope with the oxidative damage caused by reactive oxygen species (ROS)

  12. N Accumulation and Translocation in Four Japonica Rice Cultivars at Different N Rates

    2007-01-01

    Developing high-yielding rice (Oryza aativa L.) cultivara depends on having a better understanding of nitrogen (N)accumulation and translocation to the ear during the reproductive stage. Field experiments were carried out to evaluate the genetic variation for N accumulation and translocation in different Japonica rice cultivars at different N rates and to identify any relationship to grain yield in southeast China. Four Japonica cultivars with similar agronomic characteristics were grown at two experimental sites in 2004 with three N rates of 0, 60, and 180 kg N ha-1. Dry weights and N contents of rice plants were measured at tillering, initiation, anthesis, and maturity. Grain yields exhibited significant differences (P < 0.05) among the cultivars and N application rates. Increasing N rates improved N uptake at anthesis and maturity in all four cultivars (P <0.05). N translocation from vegetative organs to the grains increased with enhanced N rates (P <0.05). N translocation to the grains ranged from 9 to 64 kg N ha-1 and N-translocation efficiency from 33% to 68%.Grain yield was linear to N uptake at anthesis (r2 = 0.78**) and N translocation (r2 = 0.67**). Thus, cultivars with a high N uptake at anthesis, low residual N in the straw at maturity, and appropriate low N fertilizer supply in southeast China should efficiently increase N-recovery rate while maintaining grain yield and soil fertility.

  13. Mutant p53 accumulates in cycling and proliferating cells in the normal tissues of p53 R172H mutant mice

    Goh, Amanda M.; Xue, Yuezhen; Leushacke, Marc; LI, LING; Wong, Julin S.; Chiam, Poh Cheang; Rahmat, Siti Aishah Binte; Mann, Michael B.; Mann, Karen M.; Barker, Nick; Lozano, Guillermina; Terzian, Tamara; Lane, David P

    2015-01-01

    The tumour suppressor p53 is regulated primarily at the protein level. In normal tissues its levels are maintained at a very low level by the action of specific E3 ligases and the ubiquitin proteosome pathway. The mutant p53 protein contributes to transformation, metastasis and drug resistance. High levels of mutant p53 can be found in tumours and the accumulation of mutant p53 has previously been reported in pathologically normal cells in human skin. We show for the first time that similarly...

  14. Fenton process-affected transformation of roxarsone in paddy rice soils: Effects on plant growth and arsenic accumulation in rice grain.

    Qin, Junhao; Li, Huashou; Lin, Chuxia

    2016-08-01

    Batch and greenhouse experiments were conducted to examine the effects of Fenton process on transformation of roxarsone in soils and its resulting impacts on the growth of and As uptake by a rice plant cultivar. The results show that addition of Fenton reagent markedly accelerated the degradation of roxarsone and produced arsenite, which was otherwise absent in the soil without added Fenton reagent. Methylation of arsenate was also enhanced by Fenton process in the earlier part of the experiment due to abundant supply of arsenate from Roxarsone degradation. Overall, addition of Fenton reagent resulted in the predominant presence of arsenate in the soils. Fenton process significantly improved the growth of rice in the maturity stage of the first crop, The concentration of methylated As species in the rice plant tissues among the different growth stages was highly variable. Addition of Fenton reagent into the soils led to reduced uptake of soil-borne As by the rice plants and this had a significant effect on reducing the accumulation of As in rice grains. The findings have implications for understanding As biogeochemistry in paddy rice field receiving rainwater-borne H2O2 and for development of mitigation strategies to reduce accumulation of As in rice grains. PMID:27060198

  15. Main agronomic traits and resistance to rice blast of space-induced mutant lines of Zhong-er-ruan-zhan

    The main agronomic traits and resistance to rice blast of 34 space-induced lines from an elite rice cultivar, Zhong-er-ruan-zhan were evaluated at their SP4. The resistance to blast of the mutant lines had been tested by two blast isolates previously. It was found that the mutant lines showed significant difference in plant height, effective panicles, panicle length and grains per panicle etc. from their parent. The range of variation in 1000-grain weight the largest, followed by the seed-setting rate, and that of effective panicles was the least among all the traits. Except for the line Z34, 33 mutant lines had broader resistance spectra than the wild-type based on the test with 38 different blast isolates, and all the 33 lines were also resistant to the panicle blast in the field. The result confirmed that selection for resistant to blast in lower generations was reliable. Taking account of agronomic traits and blast resistance, promising lines with resistance to blast and good agronomic characters could be selected from those mutant lines. Therefore, the elite rice germplasm with enhanced disease resistance can be produced. (authors)

  16. Translocation, accumulation and distribution of 137Cs in rice after foliage contamination

    The single leaf of rice stem was artificially contaminated with 137Cs at different growth stages to study its foliage absorption and translocation. The results showed that the translocation rate of 137Cs to non-contaminated parts of the plant was related with the phyllo-taxis of the contaminated leaf and the majority of 137Cs in the plant was distributed in leaves and stems. For rice being contaminated, there was a positive linear relationship between the accumulation of 137Cs in each non-contaminated part of the plant and the amount of the contamination. The order of the specific activity of 137Cs was: Leaf>Stem>root>ear in non-contaminated parts of the plant

  17. Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima.

    Yang, Baolu; Onda, Yuichi; Wakiyama, Yoshifumi; Yoshimura, Kazuya; Sekimoto, Hitoshi; Ha, Yiming

    2016-01-01

    About half of the total paddy field area, which is the dominant agricultural land in Fukushima Prefecture, was contaminated by radiocesium released by the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the temporal changes of radiocesium in soil, irrigation water, and rice plant in two adjacent rice paddies, with and without surface-soil-removal, in Fukushima Prefecture for over three years (2012-2014) after the nuclear accident. Our results showed that radiocesium migrated into 24-28 cm soil layers and that the activity concentration of radiocesium in paddy soils showed a significant reduction in 2014. The newly added radiocesium to paddies through irrigation water contributed only a maximum value of 0.15% and 0.75% of the total amount present in control and decontaminated paddies, respectively, throughout the study period. The radiocesium activity concentration in suspended sediment in irrigation water exponentially decreased, and the effective half-lives (Teff) for (137)Cs and (134)Cs were 1.3 and 0.9 years, respectively. Additionally, the average suspended sediment concentration in irrigation water increased between 2012 and 2014, suggesting that enhanced soil erosion had occurred in the surrounding environment. Radiocesium accumulation in rice plant also decreased with time in both paddies. However, the concentration ratio of radiocesium for rice plant in the decontaminated paddy increased compared with control paddy, despite approximately 96% of fallout radiocesium removed in paddy soil. Further analysis is required to clarify the reasons of high concentration ratio of radiocesium for rice plant in the decontaminated paddy. PMID:26561453

  18. [Pigment accumulation and functional activity of chloroplasts in common Pisum sativum L. mutants with low chlorophyll level (chlorotica)].

    Ladygin, V G

    2003-01-01

    Pea mutants chlorotica 2004 and 2014 with a low content of chlorophyll were studied. The mutant 2004 has light green leaves and stem, and the mutant 2014 has yellow green leaves and stem. They accumulate approximately 80 and 50% chlorophylls of the parent form of pea Torsdag cv. The content of carotene in carotenoids of the mutant 2004 was much lower, and the accumulation of lutein and violaxanthine was increased. The accumulation of all carotenoids in the mutant 2014 decreased almost proportionally to a decrease in the chlorophyll content. The rate of CO2 evolution in mutant chlorotica 2004 and 2014 was established to be lower. The quantum efficiency of photosynthesis in the mutants was 29-30% lower as compared to the control, and in hybrid plants it was 1.5-2-fold higher. It is assumed that the increase in the activity of the night-time respiration in gas exchange of chlorotica mutants and the drop of photosynthesis lead to a decrease in biomass increment. The results obtained allow us to conclude that the mutation of chlorotica 2004 and 2014 affects the genes controlling the formation and functioning of different components of the photosynthetic apparatus. PMID:12723346

  19. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium.

  20. Evaluation of Supa and Salama rice mutant lines for development of a suitable rice variety as candidate to improve food security and contribute to poverty reduction among small holder rice farmers

    Rice is the most preferred staple food in Zanzibar. It is grown by most household in rural areas and forms a very important crop terms of food security. The main ecology of its production is rain fed condition which is faced with so many constraints such as low yield potential (with an average yield of 1.5t/ha), weed infestations, stem bores attack, RYMV and rice blasts. The objective of this trial was to evaluate rice mutant lines to determine suitable varieties for recommendation to farmers. On-station and on-farm field experiments were conducted both in Pemba and Unguja to evaluate rice mutant materials under rain fed lowland conditions. This trial was part of rice improvement programme through IAEA/URT/5/020 project 'enhancing crop productivity through radiation technology'. Twenty-four mutant lines of Supa and Salama were obtained from Sokoine University of Agriculture (SUA) and were grown in the first season when twelve lines were selected for a second season evaluation. Six superior lines were then evaluated under farmers' fields in Pemba and Unguja. The results of yield and yield components showed that Supa BC line ( a back cross of mutant 100 with Supa) was the best line (p=0.05). Many farmers in the tested rice irrigated schemes are now using Supa BC as their new preferred variety even though it has not been released officially. It is therefore recommended that more sites are tried with the variety so that it can be officially released as a new variety and therefore recommended to be used nationwide.(author)

  1. Effects of Formulated Fertilizer Synergist on Abscisic Acid Accumulation, Proline Content and Photosynthetic Characteristics of Rice under Drought

    WANG Shao-xian; XIA Shi-tou; PENG Ke-qin; KUANG Feng-chun; CAO Yong; XIAO Lang-tao

    2007-01-01

    To investigate the effects of formulated fertilizer synergist on the drought tolerance in rice, pot experiment was conducted to analyze the photosynthetic characteristics and the accumulation of abscisic acid (ABA) and proline in middle-season rice variety Peiliangyou 93. The synergist could improve the net photosynthetic rate, and coordination between the water loss and the CO2 absorption as well as reduce the harmful effect on photosynthetic process under drought conditions. Under drought, the ABA accumulated massively both in roots and leaves, while the ABA content in roots was far higher than that in leaves. The results indicate that synergist could increase the ABA accumulation, but reduce the proline accumulation in rice plant under drought.

  2. Accumulation of the chalcone isosalipurposide in primary leaves of barley flavonoid mutants indicates a defective chalcone isomerase

    Mutants defective in flavonoid biosynthesis have become increasingly useful in elucidating the potential functions of these compounds in plants. To define the role of flavonoids as UV-B protectants in barley, we have screened part of the collection of proanthocyanidin-free barley mutants at the Carlsberg Research Laboratory, Copenhagen, Denmark. The four mutants ant 30–245, ant 30–272, ant 30–287 and ant 30–310 showed drastically reduced flavonoid levels in the primary leaf as compared to their corresponding parent varieties, and in addition accumulated a new mutant-specific phenolic compound which was identified as the chalcone glucoside isosalipurposide. Results from diallelic crosses indicate that all four mutants belong to the same new complementation group, which is designated as the Ant 30 locus. This gene has not earlier been described in barley. The data presented suggest a defective chalcone isomerase gene for the observed flavonoid pattern in leaves of ant 30 mutants. (author)

  3. Effect of biochars and microorganisms on cadmium accumulation in rice grains grown in Cd-contaminated soil.

    Suksabye, Parinda; Pimthong, Apinya; Dhurakit, Prapai; Mekvichitsaeng, Phenjun; Thiravetyan, Paitip

    2016-01-01

    Cadmium (Cd) contaminated in rice grains is a serious problem because most Asians consume rice on a daily basis. Rice grown in Cd-contaminated soil normally did not have high concentration of Cd. However, soil samples used in this study had high concentrations of Cd. The purpose of this study was to clearly see the effects of biochar and microorganism addition in rice growing in Cd-contaminated soil. The initial Cd concentration in Cd-contaminated soil used in this study was about 650 mg kg(-1). Cadmium concentration in rice plants grown in Cd-contaminated soil with the addition of 1% (w/w) different biochars such as sawdust fly ash (SDFA), bagasse fly ash (BGFA), and rice husk ash (RHA) was investigated. The results showed that SDFA was the best biochar in terms of reducing cadmium accumulation in rice grains when compared to BGFA and RHA under the same conditions. In addition, rice plants grown in Cd-contaminated soil with the addition of various nonpathogenic microorganisms, such as Pseudomonas aeruginosa, Bacillus subtilis, and Beauveria bassiana were also studied. The results showed that the addition of 2% (v/v) microorganisms can reduce Cd accumulation in grains. It was found that grains obtained from Cd-contaminated soil with the addition of P. aeruginosa had the lowest cadmium concentration compared to the ones from soil amended with other strains. This was due to the fact that P. aeruginosa adsorbed more Cd itself into its cells than other strains. The rice plants grown in Cd-contaminated soil with the addition of biochars and microorganisms were also compared. The results showed that adding 2% (v/v) microorganisms seemed to reduce Cd accumulation in rice grains better than adding 1% (w/w) biochars. In addition, the amounts of calcium and magnesium in rice grains and the dry weight of plant in Cd-contaminated soil amended with P. aeruginosa were the highest in comparison to other microorganisms, biochars, and the soil without any amendments (Cd

  4. Increased leaf photosynthesis caused by elevated stomatal conductance in a rice mutant deficient in SLAC1, a guard cell anion channel protein

    Kusumi, Kensuke; Hirotsuka, Shoko; Kumamaru, Toshiharu; Iba, Koh

    2012-01-01

    In rice (Oryza sativa L.), leaf photosynthesis is known to be highly correlated with stomatal conductance; however, it remains unclear whether stomatal conductance dominantly limits the photosynthetic rate. SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. In order to examine stomatal limitations to photosynthesis, a SLAC1-deficient mutant of rice was isolated and characterized. A TILLING screen of N-methyl-N-nitrosourea-derived mutant ...

  5. Characterization and Mapping of a Shattering Mutant in Rice That Corresponds to a Block of Domestication Genes

    Ji, Hyeon-So; Chu, Sang-Ho; Jiang, Wenzhu; Cho, Young-Il; Hahn, Jang-Ho; Eun, Moo-Young; McCouch, Susan R; Koh, Hee-Jong

    2006-01-01

    Easy shattering reduces yield due to grain loss during harvest in cereals. Shattering is also a hindrance in breeding programs that use wild accessions because the shattering habit is often linked to desirable traits. We characterized a shattering mutant line of rice, Hsh, which was derived from a nonshattering japonica variety, Hwacheong, by N-methyl-N-nitrosourea (MNU) treatment. The breaking tensile strength (BTS) of the grain pedicel was measured using a digital force gauge to evaluate th...

  6. Selection and Semi-Dwarf Allele Mutants Segregation Pattern as the Result of Gamma Ray Irradiation of West Sumatera Black Rice

    Benny Warman

    2015-01-01

    Full Text Available Black rice is a local rice originating from East Pasaman which has a low yield potential, long panicles, too high of longevity and plant height and soeasily fall. To reduce  plant height has been irradiated rice seedsas much as 200 grams of black rice with a dose of 200 Gy of gamma rays. This study aimed to obtain information about the frequency of mutant semi-dwarf/dwarf and segregation patterns in mutant alleles black rice as the genetic improvement of West Sumatra local rice through mutation induction.  From the selection of the M2 generation gained 31 candidates dwarf/semi dwarf mutant frequency of 0.062%. also obtained information that the segregation of alleles that make up the character ofthe semi dwarf/dwarf rodon rice mutant semi dwarf/dwarf trunked together with the distribution pattern of segregation according to Mendel's Law. On the character of the semi-dwarf/dwarf stem is influenced by one or two groups of alleles, where one of the alleles controlling the properties of semi-dwarf/dwarf stem, while the other controls the high stemproperties. Alleles from each group are in a locus that its chromosomes separate.It is evident that the semi-dwarf/dwarf on the mutant is occured due to one or more alleles is dominant on the high stem properties controlling alleles group toward the recessive.

  7. Genetic analysis and fine-mapping of a dwarfing with withered leaf-tip mutant in rice

    2008-01-01

    A dwarf mutant of rice(Oryza.sativa L.)by mutagenesis of ethylene methylsulfonate(EMS)treatment from Nipponbare was identified.The mutant exhibited phenotypes of dwarfism and withered leaf tip(dwll).Based on the internode length of dwl1,this mutant be longs to the dm type of dwarfing.Analysis of elongation of the second sheath and α-amylase activity in endosperm showed that the phenotype caused by dwll was insensitive to gibberellin acid treatment.Using a large F2 population derived from a cross between the dwll and an indica rice variety,TN1,the DWLl gene was mapped to the terminal region of the long arm of chromosome 3.Fine-mapping de-limited it into a 46 kb physical distance between two STS markers,HL921 and HL944,where 6 open reading frames were predicted.Cloning of DWL1 will contribute to dissecting molecular mechanism that regulates plant height in rice,which will be beneficial to molecular assisted selection of this important trait.

  8. Induction and evaluation of low phytic acid mutants in basmati rice

    Induced mutations are successfully used to alter a character in an otherwise very well adapted variety. Keeping in view the adverse effects of high phytate contents in various cereal and legume crops, present work was started to develop the low phytate basmati rice through induced mutation. Paddy seeds of Super Basmati (well-adapted variety) were exposed to different doses of gamma rays (150, 200, 250, 300, 350 and 400 Gy) and screened for high levels of inorganic phosphorus (Biologically available form of phosphorus) in the M2 generation. Subsequently, selected mutants were evaluated up to M5 generation using the colorimetric assay technique. One progeny in M5 and two progenies in M4 generation were found stable for low phytic acid (Lpa) mutations and were confirmed through HPLC exhibiting 58.33%, 54.4% and 53.98% inorganic-P respectively as compared to Super Basmati (9.86%). Agronomic traits and physical paddy parameters in the selected progenies were comparable with Super Basmati except one progeny which had short paddy length. The results based on these studies are discussed. (author)

  9. Revealing the Complex System of Starch Biosynthesis in Higher Plants Using Rice Mutants and Transformants

    Starch is the end product of photosynthesis and a primary material for food and industrial uses. Starch has a variety of distinct physico-chemical properties such as gelatinization and pasting properties, and these features are strongly related to the molecular structure of amylopectin and the formation of starch granules, whose morphology depends on the plant species. The multi-dimensional, unique structure of starch is achieved by concerted reactions catalyzed by multiple isozymes of a set of enzymes that include starch synthase, starch branching enzyme and starch debranching enzyme. The action mechanism of each of these isozymes is currently being studied. This paper summarizes recent results of biochemical and genetic analyses of starch biosynthesis in rice endosperm obtained from various mutants and transformants, and dis- cusses ideas about the regulation of starch biosynthesis in plants. Starch is glucose polymer with two α-glucosidic linkages, linearly linked α-1,4-glucosidic chains are branched by α-1,4-glucosidic linkages, and it comprises linear or rarely branched amylose and highly branched amylopectin. Amylopectin has a distinct highly ordered structure called a 'tandem-cluster structure', in which most of side chains are arranged in parallel and neighboring chains form double helices when linear portions of facing chains reach the length equivalent to degree of polymerization (DP) ≥ 10. The formation of double helices in the amylopectin cluster dramatically induces its hydrophobicity and crystallinity. These specific features of amylopectin fine structure are enabled by the localization of branch positions within the restricted region of the cluster. The starch synthesis system has developed during the evolution of plants and key enzymes involved in the construction of amylopectin tandem-cluster structure have differentiated into multiple isozymes with distinct functions, whereas in glycogen synthesizing organisms, such as bacteria and animals

  10. Effects of feeding outer bran fraction of rice on lipid accumulation and fecal excretion in rats.

    Ijiri, Daichi; Nojima, Tsutomu; Kawaguchi, Mana; Yamauchi, Yoko; Fujita, Yoshikazu; Ijiri, Satoru; Ohtsuka, Akira

    2015-01-01

    Outer bran fraction of rice (OBFR) contains higher concentrations of crude fiber, γ-oryzanol, and phytic acid compared to whole rice bran (WRB). In this study, we examined the effects of feeding OBFR on lipid accumulation and fecal excretion in rats. Twenty-one male rats at seven-week-old were divided into a control group and two treatment groups. The control group was fed a control diet, and the treatment groups were fed OBFR- or WRB-containing diet for 21 days. There was no significant difference in growth performance. Feeding OBFR diet increased fecal number and weight accompanied by increased fecal lipid content, while it did not affect mRNA expressions encoding lipid metabolism-related protein in liver. In addition, feeding OBFR-diet decreased the abdominal fat tissue weight and improved plasma lipid profiles, while WRB-containing diet did not affect them. These results suggested that feeding OBFR-diet might prevent lipid accumulation via enhancing fecal lipid excretion in rats. PMID:25867004

  11. Neutral lipid accumulation at elevated temperature in conditional mutants of two microalgae species

    Yao, Shuo; Brandt, Anders Bøving; Egsgaard, Helge;

    2012-01-01

    mutants of Chlamydomonas reinhardtii and Chlorella vulgaris, nine out of fourty-one mutants in C. reinhardtii and eleven out of fifty-three mutants in C. vulgaris contained increased amounts of neutral lipids, predominantly as triacylglycerols. Upon temperature induced cell-cycle arrest, these mutants...

  12. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins.

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium. PMID:27559341

  13. Characterization of cadmium-resistant bacteria and their potential for reducing accumulation of cadmium in rice grains.

    Lin, Xiaoyan; Mou, Renxiang; Cao, Zhaoyun; Xu, Ping; Wu, Xiaoliang; Zhu, Zhiwei; Chen, Mingxue

    2016-11-01

    Cadmium (Cd) pollution is a serious widespread environmental problem that not only destroys the microbial ecology of soil and decreases crop production, but also poses a serious risk to human health. Many methods have been used for the remediation of Cd pollution but none of these is totally satisfactory. Microbial remediation strategies have attracted increasing interest since they are environmentally friendly and cost-effective. In the present study, three Cd-resistant bacteria were isolated and evaluated for potential application in Cd bioremediation. Based on their morphological, physiological and biochemical characteristics, together with 16S rDNA gene sequence analyses, bacteria were identified as Stenotrophomonas acidaminiphila (2#), Pseudomonas aeruginosa (9#) and Delftia tsuruhatensis (12#). Pseudomonas aeruginosa showed very high tolerance to metals, especially Cd (2200mg/L), Zn (1800mg/L) and Pb (1200mg/L), and is thought to be a multi-metal-resistant bacterium. Pseudomonas aeruginosa was also sensitive to 13 different antibiotics. The effects of the bacterial strains on the growth of rice plants and their ability to reduce Cd accumulation from Cd-contaminated soils in pot experiments were also evaluated. For Oryza sativa L. A grown in contaminated soil (3mg/kg Cd), the accumulation of Cd was decreased by 31.2 and 25.5% in brown rice and polished rice, respectively, by strain 9#; Pseudomonas aeruginosa was more effective in reducing Cd accumulation in rice grains than a mixture of strains. For Oryza sativa L. B, a mixture of strains acting synergistically was more effective than a single strain in reducing Cd accumulation; treatment with mixed strains (strains+3mg/kg Cd) resulted in 41.3, 35.9, and 32.6% reductions in Cd accumulation in unhulled rice, brown rice and polished rice, respectively. Although different results were obtained for two rice varieties, it can still be concluded that Cd-resistant bacteria are suitable for reducing Cd accumulation in

  14. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH4)2SO4 as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM

  15. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    Cao, Fangbin; Wang, Runfeng [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Cheng, Wangda [Jiaxing Academy of Agricultural Sciences, Jiaxing 314016 (China); Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Wu, Feibo, E-mail: wufeibo@zju.edu.cn [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China)

    2014-10-15

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH{sub 4}){sub 2}SO{sub 4} as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM.

  16. Development and characterization of Katy deletion mutant populations for functional genomics of host-parasite interactions and rice improvement

    To facilitate functional genomics studies and rice improvement, the US rice cultivar Katy was mutagenized by ethyl methane sulfonate (EMS), fast neutrons and gamma irradiations in cooperation with Jiangxi Agricultural Academy of Agricultural Science. Seeds were soaked in 0.4%, 0.8% and 1.2 % EMS solutions for 6 hours and a total of 7199 M1 lines were recovered. Seven dosages of fast neutron were applied and a total of 15400 M1 lines were recovered from treatments with 7.7 Gy, 26.3 Gy and 49.4 Gy. Preliminary analysis of M2 seedlings revealed defects in chlorophyll synthesis in a range of 1.06% - 5.04% of M1 derived lines. Katy containing the blast resistance gene Pi-ta prevents infection by Magnaporthe grisea races in a gene-for-gene manner. M. grisea races containing the avirulence gene AVR-Pita are being used to identify susceptible mutants and M. grisea races lacking AVR-Pita are being used to screen resistant mutants. Sekiguchi lesion mimic-like mutants of Katy were recovered from lines induced by EMS, fast neutrons and gamma irradiations. Progress in genetic analysis and advancement of these putative mutant lines are described. Classical Mendelian forward genetics starts with a biological function that was identified through a mutation or phenotype variation and ends with characterization of the controlling gene. With abundant DNA sequence information, reverse genetics can be used to start with a predicted function of DNA sequences based on knowledge from model organisms, to identification of genes involved in biological function in an organism of interest. Routine methods to disrupt a gene have not yet been established for plants; however, plants are well adapted to random mutagenesis. Mutant seeds can be stored inexpensively to screen certain phenotypes or 'reverse screened'- i.e., screened based on gene sequences for mutants. To facilitate forward and reverse genetics studies, the elite US cultivar Katy containing a good disease resistant package including

  17. Increase in cellulose accumulation and improvement of saccharification by overexpression of arabinofuranosidase in rice.

    Minako Sumiyoshi

    Full Text Available Cellulosic biomass is available for the production of biofuel, with saccharification of the cell wall being a key process. We investigated whether alteration of arabinoxylan, a major hemicellulose in monocots, causes an increase in saccharification efficiency. Arabinoxylans have β-1,4-D-xylopyranosyl backbones and 1,3- or 1,4-α-l-arabinofuranosyl residues linked to O-2 and/or O-3 of xylopyranosyl residues as side chains. Arabinose side chains interrupt the hydrogen bond between arabinoxylan and cellulose and carry an ester-linked feruloyl substituent. Arabinose side chains are the base point for diferuloyl cross-links and lignification. We analyzed rice plants overexpressing arabinofuranosidase (ARAF to study the role of arabinose residues in the cell wall and their effects on saccharification. Arabinose content in the cell wall of transgenic rice plants overexpressing individual ARAF full-length cDNA (OsARAF1-FOX and OsARAF3-FOX decreased 25% and 20% compared to the control and the amount of glucose increased by 28.2% and 34.2%, respectively. We studied modifications of cell wall polysaccharides at the cellular level by comparing histochemical cellulose staining patterns and immunolocalization patterns using antibodies raised against α-(1,5-linked l-Ara (LM6 and β-(1,4-linked d-Xyl (LM10 and LM11 residues. However, they showed no visible phenotype. Our results suggest that the balance between arabinoxylan and cellulose might maintain the cell wall network. Moreover, ARAF overexpression in rice effectively leads to an increase in cellulose accumulation and saccharification efficiency, which can be used to produce bioethanol.

  18. Fermentation and quality of yellow pigments from golden brown rice solid culture by a selected Monascus mutant.

    Yongsmith, Busaba; Thongpradis, Panida; Klinsupa, Worawan; Chantrapornchai, Withida; Haruthaithanasan, Vichai

    2013-10-01

    A single peak (λmax 370) yellow pigment-producing mutant derived from Monascus sp. TISTR 3179 was used for the pigment production in solid rice culture. Various factors affecting yellow tones were investigated. Hom-mali rice variety was the best amongst five Thai local varieties used for fungus culture. It was also better than corn, mungbean, soybean, potato, sweet potato, or cassava tubers. The moisture content and temperature were the key environmental factors affecting the color tones of creamy, tangerine, and golden brown rice solid cultures. The golden brown rice culture gave the highest yellow pigment concentration. Under an optimum room temperature of 28-32 °C, an initial moisture content of 42 %, and 7-day-old inoculum size of 2 % (v/w) the maximum yield at 2,224.63 A370U/gdw of yellow pigment was produced. A mellow yellow powder at 550 A370U/gdw could be obtained using spray-drying techniques. The powder had a moisture content of 5.15 %, a water activity value of 0.398, a hue angle of 73.70 ° (yellowish orange), high lightness (L) of 74.63, color saturation (C) of 28.97, a neutral pH of 7.42, 0.12 % acidity and solubility of 0.211 g/10 ml. It was noteworthy that the Chinese fresh noodle with spray-dried yellow powder showed no discoloration during 8-day storage. PMID:23912113

  19. Mitigating heavy metal accumulation into rice (Oryza sativa L.) using biochar amendment--a field experiment in Hunan, China.

    Zheng, Ruilun; Chen, Zheng; Cai, Chao; Tie, Baiqing; Liu, Xiaoli; Reid, Brian J; Huang, Qing; Lei, Ming; Sun, Guoxin; Baltrėnaitė, Edita

    2015-07-01

    A field experiment was conducted to investigate the effect of bean stalk (BBC) and rice straw (RBC) biochars on the bioavailability of metal(loid)s in soil and their accumulation into rice plants. Phytoavailability of Cd was most dramatically influenced by biochars addition. Both biochars significantly decreased Cd concentrations in iron plaque (35-81 %), roots (30-75 %), shoots (43-79 %) and rice grain (26-71 %). Following biochars addition, Zinc concentrations in roots and shoots decreased by 25.0-44.1 and 19.9-44.2 %, respectively, although no significant decreases were observed in iron plaque and rice grain. Only RBC significantly reduced Pb concentrations in iron plaque (65.0 %) and roots (40.7 %). However, neither biochar significantly changed Pb concentrations in rice shoots and grain. Arsenic phytoavailability was not significantly altered by biochars addition. Calculation of hazard quotients (HQ) associated with rice consumption revealed RBC to represent a promising candidate to mitigate hazards associated with metal(loid) bioaccumulation. RBC reduced Cd HQ from a 5.5 to 1.6. A dynamic factor's way was also used to evaluate the changes in metal(loid) plant uptake process after the soil amendment with two types of biochar. In conclusion, these results highlight the potential for biochar to mitigate the phytoaccumulation of metal(loid)s and to thereby reduce metal(loid) exposure associated with rice consumption. PMID:25794575

  20. Light-specific transcriptional regulation of the accumulation of carotenoids and phenolic compounds in rice leaves.

    Mohanty, Bijayalaxmi; Lakshmanan, Meiyappan; Lim, Sun-Hyung; Kim, Jae Kwang; Ha, Sun-Hwa; Lee, Dong-Yup

    2016-06-01

    Carotenoids and phenolic compounds are important subgroups of secondary metabolites having an array of functional roles in the growth and development of plants. They are also major sources for health and pharmaceutical benefits, and industrially relevant biochemicals. The control of the biosynthesis of these compounds depends mainly on the quality and quantity of different light sources. Thus, to unravel their light-specific transcriptional regulation in rice leaves, we performed promoter analysis of genes upregulated in response to blue and red lights. The analysis results suggested a crosstalk between different phytohormones and the involvement of key transcription factors such as bHLH, bZIP, MYB, WRKY, ZnF and ERF [jasmonic acid inducible], in the regulation of higher accumulation of carotenoids and phenolic compounds upon blue light. Overall, the current analysis could improve our understanding of the light-specific regulatory mechanism involved in the biosynthesis of secondary metabolites via possible critical links between different TFs in rice leaves. PMID:27172458

  1. Characteristics and genetic mapping of a lesion mimic mutant pl(t) in japonica rice variety zhejing 22

    A lesion mimic mutant,obtained by radiation mutagenesis on the seeds of a japonica rice variety Zhejing 22, exhibited a lesion mimic phenotype during the whole growth stage under different environments. Genetic analysis indicated that the mutant trait was controlled by a single recessive gene named spl (t). Relying on simple sequence repeat (SSR) and recessive class analysis method to map the spl (t) gene with a F2 population was constructed by crossing the mutant spl (t) with Zhenshan 97B.spl (t) was mapped in the interval of 0.8cM between RM7195 and RM27929 near centromere region on the short arm of chromosome 12.Blue trypan dye analyses indicated that the lesion mimic trait of the mutant was caused by the programmer cell death. Further study showed that the programmer cell death was caused by H2O2 oxidative burst. By inoculation of bacterial leaf blight and blast strains, the resistances of the mutant were similar to the wild variety Zhejing 22. (authors)

  2. Analysis of Chloroplast Ultrastructure, Photosystem Ⅱ Light Harvesting Complexes and Chlorophyll Synthesis in a Chlorophyll-Less Rice Mutant W2555

    XU Pei-zhou; LI Yun; YUAN Shu; ZHANG Hong-yu; WANG Xu-dong; LIN Hong-hui; WU Xian-jun

    2006-01-01

    A comparative study on chloroplast ultrastructure and light harvesting complex of photosystem Ⅱ (LHC Ⅱ) was conducted between a new rice mutant (W2555) and its wild type (WT). The chloroplasts of W2555 had less thylakoids and grana stacks compared with the wild type. There was no significant change in the composition of LHC Ⅱ polypeptide in W2555, while a decline had been noted in LHC Ⅱ content. Northern blot analysis with a specific cab gene probe showed no appreciable difference in the LHC Ⅱ mRNA level between the W2555 and its wild type. The precursors of chlorophyll synthesis, δ-aminolevulinic acid (ALA)and porphobilinogen (PBG) were over accumulated in W2555, but the other precursors were all decreased. These results indicated that the decreased level of LHC Ⅱ in the mutant W2555 was attributed to the change of cab gene transcription, but a blockage in chlorophyll biosynthesis due to the formation of uroporphyrinogen Ⅲ (Urogen Ⅲ).

  3. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-01-01

    Highlight Long-lived mRNAs stored in dry seed are translated after imbibition for germination. We report accumulation of long-lived mRNAs in developing rice embryos and candidates of the mRNAs required for germination.

  4. Genetic analysis and gene fine mapping for a rice novel mutant (rl9(t)) with rolling leaf character

    2006-01-01

    Leaf shape is an important parameter for ideotype breeding in rice, and the rolling of leaf is also beneficial to efficient ripening of grains. This encourages the explorations of new genes that regulate leaf shape. In this study, genetic analysis and gene mapping were carried out for a novel rolling leaf mutant identified from japonica variety Zhonghua 11. The SSR marker analysis showed that the mutant was controlled by a single recessive gene (rl9(t)) located on chromosome 9. Fine mapping of the Rl9(t) locus was conducted with 30 new STS markers developed around Rl9(t) anchored region based on the sequence diversity between Nipponbare and 93-11. The fine mapping necessitated the contruction of a PAC contig encompassing the Rl9(t) locus, which was delimited to a 42 kb region. This could therefore enhance the cloning of the target gene in further studies.

  5. The Difference in Growth and Four Microelement Concentrations Between Two Rice Genotypes Differing in Grain Cadmium-Accumulating Capacity

    CHENG Wang-da; ZHANG Guo-ping; YAO Hai-gen; Peter Dominy; WANG Run-yi

    2004-01-01

    A pot experiment was conducted with two rice genotypes having different Cd concentrations in their grains to study the effect of soil Cd level on biomass, Cd and Fe, Zn, Cr and Pb accumulation in different plant parts. Cd was added into soil to form 4 levels, i.e.,0, 0.5, 2.5 and 12.5 mg kg-1, respectively. The results showed that the Cd-induced reduction in biomass accumulation varied in both genotypes and growth stages. The Cd-induced reduction in biomass became less with the progress of growth, and Xiushui63, a genotype with relatively higher grain Cd concentration, was more severely inhibited than Xiushui217,a relatively lower Cd concentration. Both Cd concentration and accumulation in the various plant parts increased substantially with the increase of Cd levels. The difference between two genotypes in Cd concentration and accumulation became more pronounced with increased Cd level as well as prolonged duration of exposure. Xuishui63 had much greater Cd accumulation than Xiushui217, in particular at late growth stage. Xuishui63 had a remarkably higher Cd translocation of roots to shoots than Xiushui217 in all Cd levels.The effect of Cd addition on four microelement concentrations in straw and milled rice also varied in genotypes and Cd levels. Without Cd addition, Xiushui63 was significantly lower than Xiushui217 in the concentrations of all four elements in straw, while the case was just opposite in milled rice. Zn, Fe and Pb concentrations decreased in milled rice with the increase of Cd level, although the reduction extent differed in two genotypes.The results indicated that Cd concentration in rice grain is primarily dependent on the shoot Cd concentration, which is in turn mainly determined by Cd translocation from roots to shoots.

  6. Gamma-rays induced early heading and dwarf mutants in rice

    Progenies of 60 mutant lines of three early heading and/or dwarf mutant types namely 1-early heading (180-1), 2-early heading, dwarf (180-5) and 3-dwarf with early heading and fine grains (180-70) were selected from M3 generation and grown in M4 generation in a randomized complete block design with three replications to study the characteristics of selected mutant lines in comparison with the original variety, Giza 180. Only 20 promising mutant lines were selected in this generation (10 from the first mutant type and 5 from each of the second and third mutant types). Bulked-M5 seeds of each mutant line and the parental cultivar were sown in M5 generation. The collected data were similar to those followed in M4 generation. The results of combined analysis of M4 and M5 generations showed significant decrease in most studied traits of different mutant lines, except significant increase in no. of spikelets per panicle and panicle density in the mutant line 180-1-14 and for no. of productive tillers per plant in the mutant 180-5-4. However, the mutant lines number, 180-1-120 did not significantly differ from the parental variety, in grain yield. (author)

  7. Evaluation and characterization of advanced rice mutant line of rice (Oryza sativa), MR219-4 and MR219-9 under drought condition

    Two advance rice mutant lines, MR219-4 and MR219-9 derived from mutagenesis of Oryza sativa cv. MR219 with gamma radiation at 300 Gy were evaluated in simulated drought condition in the greenhouse at Malaysian Nuclear Agency. The mutants were evaluated simultaneously with ARN1, a drought resistant variety and MR211 a susceptible cultivar as a check. Randomized complete block design with three replicates was used in the experiment. The evaluation and selection were done based on leaf rolling and leaf drying as well as other agronomic traits, such as, number of tillers per plant, plant height, flag leaf area, grain weight per plant, grain yield per plant, 100-grain weight, harvest index, panicle length and plant biomass. The mutants MR219-4 showed moderate tolerance and MR219-9 showed tolerance to drought respectively as compare to the check variety (ARN1, MR211) and control MR219. Leaf rolling, leaf drying, days to flowering and days to maturity are valuable secondary traits that may provide additional information for selection because of associating with the plant survival under water stress. Further research on expression of drought-tolerant lines under different drought conditions is essential in order to identify particular traits that are associated with drought tolerance and high yield potential. Similarly the importance of secondary traits, relative to other putative traits for drought tolerance, needs to be tested in various environments. (author)

  8. Response of a semi-dwarf mutant of rice (Oryza sativa L.) to application of gibberelic acid

    The role of gibberellic acid (AG3) on the capacity of elongation of the nodes of a semi-dwarf mutant of rice 2B-95, was studied. This mutant, with a height between 65 to 90 cm, was obtained by Co-60 gamma irradiation from a material called WS tall with an average height of 165 cm. Variety semi-dwarf CR-1113 was used as an additional control. The work was carried out under conditions in vitro applying the AG3 in concentrations of 0.20, 30 and 40 ppm. The answer of the mutant and of the other two genotypes to exogenous application of the hormone was assessed by measuring the length of the second leaf sheath emerged after germination of the seed according to a special modification of the methodology of Harada and Vergara (1971). The results have indicated that WS genotypes and CR-1113, the length of the sheath of the second leaf at 11 days old, increased by all concentrations of AG3 evaluated, while in the semi-dwarf mutant 2B-95 the effect was only significant (P 3. (author)

  9. Genetic analysis and gene mapping of a new rolled-leaf mutant in rice (Oryza sativa L.)

    2009-01-01

    To understand the development of rice leaf blades,we identified a new rolled-leaf mutant,w32,from indica cultivar IR64 through EMS mutagenesis. The mutant showed a stable rolled-leaf phenotype throughout the life cycle. Two F2 populations were developed by crossing w32 to cultivar IR24 and PA64. Genetic analysis showed that the rolled-leaf phenotype was controlled by a single recessive gene. To determine the location of the gene,bulked segregant analysis was carried out using mutant and wild-type DNA pools and 1846 mutant-type F2 individuals derived from the cross w32/PA64 were genotyped to locate the gene on the short arm of chromosome 7. The rolled-leaf gene,tentatively named rl11(t),is likely a new gene as no other rolled-leaf genes have been identified near the region. By developing new SSR and InDel markers,the gene was delimited to a 52 kb region near the end of the short chromosome arm. Further fine mapping and cloning of the gene are currently underway.

  10. A New Green-Kerneled Glutinous Rice Mutant Variety, 'Nogwonchalbyeo' Developed by Gamma Ray Irradiation

    We bred a new green-kerneled glutinous rice variety that can be cultivated in the whole area of Korea, because only one native green-kerneled glutinous rice cultivar, 'Saengdongchalbyeo', has been cultivated in the southern coastal area due to its late heading. The seeds of 'Saengdongchalbyeo' were irradiated with 200 Gy of gamma ray in 1995. A promising mutant variety, 'Nogwonchalbyeo' ('Wonnong 17') was selected through line selection and regional yield trials. In particular, the new variety revealed at the earlier mid of August compared to that of 'Saengdongchalbyeo', the early of September, and it was considerably tolerant to a field lodging due to its shortened culm length. Also, 'Nogwonchalbyeo' had a higher ripened grain ratio and 1,000 grain weight compared to the original variety. The brown grain yield of the new variety was about 5.40 MT/ha, which was 11.3% higher than that of the original variety, in the regional yield trials at 3 different fields during 2000~2001. The brown and milled grains of the new rice variety contained 20 to 65% higher amount of total amino acids, respectively than that of the original and two checks. For chlorophyll -a, -b and total chlorophyll, the new variety showed nearly two-fold higher than the checks, and for the carotenoid, it had 5.3 - 7.6 times higher amount. These results showed that the new variety can be cultivated as a special green-kerneled glutinous rice with high functional compounds

  11. Response of Early Maturity Mutant Lines of Low Land Rice on Several Levels of NPK Fertilizers and Irrigation

    A problem which will occur in the IP400 program is the exploitation of nutrient and water. This problem could be overcome by using early maturating having high fertilizer and water use efficiency. For this purpose several mutant lines were tested for their efficiency on using fertilizers and water. The testing of the mutant lines were done in the field at the experimental station of the Agricultural Department Pusakanagara, West Java. Treatments employed were six mutant lines and two rice varieties which four rates of NPK fertilizers (0, 25, 50, and 100%) and three irrigation regimes (continuously sub merging, 10 and 15 days of alternate sub merging). The soil water content was determined by neutron probe at the start of each water regimes. The N total mutant of the plants were carried out at the Plant Nutrition Laboratory, PATIR-BATAN. Results showed that the average yield, in sequence from the highest to the lowest (t/ha) is OBS 1705 (9,3597), Cimelati (8,9631), OBS 1700 (8,9192), Diah Suci (8,7706), OBS 1713 (8,2797), OBS 1703 (8,2733), OBS 1718 (8,2489) and OBS 1704 (8,0019). Statistically highest yield/ha was obtained at all the water regimes and NPK fertilizer rates was shown by OBS 1705 and did not differ significantly from Cimelati variety, but it significantly differ from Diah Suci variety, OBS 1713, OBS 1703, OBS 1718 and OBS 1718. The OBS 1704 was highly responsive to the NPK fertilization, producing and increase any weight at the lowest rate of NPK fertilization (25%). The uptake of total nitrogen (kg N/ha) in the grain of the mutant lines were all higher than that of the parent lines (Cimelati and Diah Suci). (author)

  12. Characterization of a null allelic mutant of the rice NAL1 gene reveals its role in regulating cell division.

    Dan Jiang

    Full Text Available Leaf morphology is closely associated with cell division. In rice, mutations in Narrow leaf 1 (NAL1 show narrow leaf phenotypes. Previous studies have shown that NAL1 plays a role in regulating vein patterning and increasing grain yield in indica cultivars, but its role in leaf growth and development remains unknown. In this report, we characterized two allelic mutants of NARROW LEAF1 (NAL1, nal1-2 and nal1-3, both of which showed a 50% reduction in leaf width and length, as well as a dwarf culm. Longitudinal and transverse histological analyses of leaves and internodes revealed that cell division was suppressed in the anticlinal orientation but enhanced in the periclinal orientation in the mutants, while cell size remained unaltered. In addition to defects in cell proliferation, the mutants showed abnormal midrib in leaves. Map-based cloning revealed that nal1-2 is a null allelic mutant of NAL1 since both the whole promoter and a 404-bp fragment in the first exon of NAL1 were deleted, and that a 6-bp fragment was deleted in the mutant nal1-3. We demonstrated that NAL1 functions in the regulation of cell division as early as during leaf primordia initiation. The altered transcript level of G1- and S-phase-specific genes suggested that NAL1 affects cell cycle regulation. Heterogeneous expression of NAL1 in fission yeast (Schizosaccharomyces pombe further supported that NAL1 affects cell division. These results suggest that NAL1 controls leaf width and plant height through its effects on cell division.

  13. Reducing total mercury and methylmercury accumulation in rice grains through water management and deliberate selection of rice cultivars

    Rice consumption has been identified as a major route of methylmercury (MeHg) exposure in some areas of inland China. We investigated two potential mitigation methods (water management and deliberate selection of rice cultivars) to reduce the amount of total mercury (Hg) and MeHg within the grain. Rice grown aerobically had markedly reduced total Hg and MeHg concentrations as well as a much lower proportion of MeHg in the grain. Remarkably, there were considerable variations in the total Hg and MeHg concentrations as well as the proportion of MeHg in the grain among the 24 cultivars grown in the same paddy soil. The Hg tolerance index (expressed as % mean of control root growth) also varied substantially among the different cultivars. Furthermore, negative correlations were found between the total Hg and MeHg concentrations (P < 0.05) of grain and the proportion of MeHg in the grain (P < 0.01). - Highlights: ► We investigate two potential mitigation methods to reduce the amount of total mercury (Hg) and MeHg in rice grain. ► Aerobic treatment markedly reduced total Hg and MeHg concentrations in the grain. ► There were considerable cultivar variations in grain total Hg and MeHg concentrations. ► Water management and cultivar selection were effective in reducing Hg exposure risk. - Total Hg and MeHg in rice grains reduced by water management and deliberate selection of rice cultivars.

  14. Soil water availability and capacity of nitrogen accumulation influence variations of intrinsic water use efficiency in rice.

    Xue, Wei; Nay-Htoon, Bhone; Lindner, Steve; Dubbert, Maren; Otieno, Dennis; Ko, Jonghan; Werner, Christiane; Tenhunen, John

    2016-04-01

    Leaf intrinsic water use efficiency (WUEi) coupling maximum assimilation rate (Amax) and transpirable water lost via stomatal conductance (gsc) has been gaining increasing concern in sustainable crop production. Factors that influence leaf Amax and WUEi in rice (Oryza sativa L. cv Unkang) at flooding and rainfed conditions were evaluated. Positive correlations for leaf nitrogen content (Nm) and maximum carboxylation rate (Vcmax), for nitrogen allocation in Rubisco enzymes and mesophyll conductance (gm) were evident independent of cropping cultures. Rainfed rice exhibited enriched canopy leaf average Nm resulting in higher Amax, partially supporting improved leaf WUEi. Maximum WUEi (up to 0.14μmolmmol(-1)) recorded in rainfed rice under drought conditions resulted from increasing gm/gsc ratio while at cost of significant decline in Amax due to hydraulically constrained gsc. Amax sensitivity related to gsc which was regulated by plant hydraulic conductance. WUEi was tightly correlated to Vcmax/gsc and gm/gsc ratios across the paddy and rainfed not to light environment, morphological and physiological traits, highlighting enhance capacity of Nm accumulation in rainfed rice with gsc at moderately high level similar to paddy rice facilitate optimization in Amax and WUEi while, is challenged by drought-vulnerable plant hydraulic conductance. PMID:26938938

  15. A UGPase1-blocked Male Sterility Mutant and its Possible Use in Hybrid Seed Production of Rice

    A rice genic male-sterile mutant was induced by chemical mutagenesis using N-methyl-N-nitrosourea, which had a pleiotropic effect on chalky endosperm. The mutant gene, ms-h, was isolated through a map-based cloning approach. The suppression of UGPase activity, caused by a splicing error at the 3' splice junction of the 14th intron of the UDP-glucose pyrophosphorylase 1 (UGPase1; EC 2.7.7.9) gene, was the cause of male sterility. This was confirmed by both RNAi and complementation-transgenic experiments. The endosperm of the mutant had more roundish and smaller starch granules, a higher frequency of long glucose chain amylose, higher ratio of Fr. III to Fr. II chains, and shorter branching of amylopectin than the wild type parent. A hybrid seed production system was proposed using the pleiotropic effect of UGPase1 gene on male-sterility and chalky endosperm. Relatively low density of chalky seeds may facilitate the early detection of male-sterile seeds in segregating populations prior to sowing by density-gradient method. (author)

  16. A UGPase1-blocked male sterility mutant and its possible use in hybrid seed production of rice

    A rice genic male-sterile mutant was induced by chemical mutagenesis using N-methyl-N-nitrosourea, which had a pleiotropic effect on chalky endosperm. The mutant gene, ms-h, was isolated through a map-based gene cloning approach. The suppression of UGPase activity, caused by a splicing error at the 3' splice junction of the 14th intron of the UDP-glucose pyrophosphorylase 1 (UGPase1; EC 2.7.7.9) gene, was the reason for male sterility. This was confirmed by both RNAi- and complementation-transgenic experiments. The starch structure of the mutant had more roundish and smaller starch granules, a higher frequency of long glucose chain amylose, higher ratio of Fr. III to Fr. II chains, and shorter branching of amylopectin than the wildtype parent. A hybrid seed production system was proposed using the pleiotropic effect of UGPase gene on male-sterility and chalky endosperm. Relatively low density of chalky seeds may facilitate the early detection of male-sterile seeds in segregating populations prior to sowing by density-gradient method. (author)

  17. Changes in Thermostability of Photosystem Ⅱ and Leaf Lipid Composition of Rice Mutant with Deficiency of Light-harvesting Chlorophyll Protein Complexes

    Yunlai Tang; Mei Chen; Yinong Xu; Tingyun Kuang

    2007-01-01

    We studied the difference in thermostability of photosystem Ⅱ (PSⅡ) and leaf lipid composition between a T-DNA insertion mutant rice (Oryza sativa L.) VG28 and its wild type Zhonghua11. Native green gel and SDS-PAGE electrophoreses revealed that the mutant VG28 lacked all light-harvesting chlorophyll a/b protein complexes. Both the mutant and wild type were sensitive to high temperatures, and the maximal efficiency of PSⅡ photochemistry (Fv/Fm) and oxygen-evolving activity of PSⅡ in leaves significantly decreased with increasing temperature. However, the PSⅡ activity of the mutant was markedly more sensitive to high temperatures than that of the wild type. Lipid composition analysis showed that the mutant had less phosphatidylglycerol and sulfoquinovosyl diacylglycerol compared with the wild type. Fatty acid analysis revealed that the mutant had an obvious decrease in the content of unsaturation of membrane lipids on the thermostability of PSll are discussed.

  18. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

    2013-07-01

    Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

  19. Inheritance and gene expression of a root-growth inhibiting mutant in rice (Oryza sativa L.)

    Full text: A root-growth inhibiting mutant was induced in the dwarf mutant line, 'Fukei 71', through ethylene-imine. The mutant is characterised by the excessive inhibition of both seminal and crown roots elongation just after germination, although its shoots grow nearly normal. To study the genetics, the mutant was crossed with its original line 'Fukei 71' and some other normal cultivars. Results show that the root-growth inhibition is controlled by a recessive gene (rt), independent of the dwarf gene, d-50(t) locus in Fukei 71. For elucidating the gene action on root morphogenesis, histological and cytological experiments were carried out using a longitudinal and transverse thin section of seminal and/or crown root tips. Observations suggest that the rt gene affects the normal formation of the epidermal system which is differentiated from the protoderm of the root apical meristem. (author)

  20. Evaluation of exotic and local rice mutants varieties/genotypes for stability in yield

    Genotype, location, year and their interactions were highly significant. The regression coefficient (b) and deviation from regression (S2d) showed significant differences. The mutant IR6- 25/1, IR6-1.0/1 and IR6-15/1 were superior in yield where as IR8 (parent) showed lowest yield performance. These mutants also showed 'b' value close to 1 and S2d was close to zero

  1. Comparative studies on physical-chemical properties and major nutritional components of rice grain in dwarf mutant resistant to insect pests and its parent

    Starch characteristics and key nutritional compositions in the dwarf mutant from transgenic rice with crylAb gene were compared with its original parent, Xiushuill. It was found that peak viscosity, hot paste viscosity and cool paste viscosity of RVA profile between the dwarf mutant and its parent were significantly different at 1% level, but apparent amylose content, gel consistence existed and breakdown viscosity of RVA profile were similar, and no significant differences existed in contents of crude protein, crude fat, total ash, amino acids and mineral compositions. It was suggested that no notable changes occurred in grain quality traits in the dwarf mutant with insect resistance. (authors)

  2. Variability, heritability and genetic advance in F2 populations of aromatic rice involving induced mutants and Basmati varieties

    The F2 generation of five cross-combinations of aromatic rice involving two induced mutants 124-17-4 and 21-6-1 of aromatic tall Indica cultivar Gobindabhog and three basmati varieties was studied for mean performance, variability, heritability and genetic advance. The cross 21-6-1/Pakistan Basmati showed higher mean values for grain yield plant, and several yield components. Wide variability was observed for panicle number plant, filled grains panicle, test weight, dry matter production plant, harvest index and grain yield plant. Among the traits, filled grains panicle and test weight in all the crosses, grain yield plant, in five crosses and harvest index in two crosses had high heritability coupled with high genetic advance indicating predominant role of additive gene action. The crosses 21-6-1/Pakistan Basmati and 124-17-4/Pusa Basmati I could be exploited for isolation of promising aromatic recombinants. (author)

  3. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Mahadtanapuk, S. [School of Agriculture and Natural Resources, University of Phayao, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Phayao 56000 (Thailand); Phanchaisri, B. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@frnf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S., E-mail: burinka@hotmail.com [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-15

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10{sup 16}–2 × 10{sup 17} ions/cm{sup 2}. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10{sup 6} spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  4. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 1016–2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  5. Variation in vein density and mesophyll cell architecture in a rice deletion mutant population

    Smillie, I.R.A.; Pyke, K.A.; Murchie, E. H.

    2012-01-01

    There is a need to develop rice plants with improved photosynthetic capacity and efficiency in order to enhance potential grain yield. Alterations in internal leaf morphology may be needed to underpin some of these improvements. One target is the production of a ‘Kranz-like’ anatomy, commonly considered to be required to achieve the desired levels of photosynthesis seen in C4 crops. Kranz anatomy typically has two or three mesophyll cells interspersing adjacent veins. As a first step to deter...

  6. Oryza Tag Line, a phenotypic mutant database for the Genoplante rice insertion line library

    Larmande, Pierre; Gay, Celine; Lorieux, Mathias; Perin, Christophe; Bouniol, Matthieu; Droc, Gaëtan; Sallaud, Christophe; Perez, Pascual; Barnola, Isabelle; Biderre-Petit, Corinne; Martin, Jérôme; Morel, Jean-Benoit; Johnson, Alexander A. T.; Bourgis, Fabienne; Ghesquière, Alain

    2008-01-01

    International audience To organize data resulting from the phenotypic characterization of a library of 30,000 T-DNA enhancer trap (ET) insertion lines of rice (Oryza sativa L cv. Nipponbare), we developed the Oryza Tag Line (OTL) database (http://urgi.versailles.inra.fr/OryzaTagLine/). OTL structure facilitates forward genetic search for specific phenotypes, putatively resulting from gene disruption, and/or for GUSA or GFP reporter gene expression patterns, reflecting ET-mediated endogenou...

  7. Characterization of a novel high-tillering dwarf 3 mutant in rice

    Bosen Zhang; Feng Tian; Lubin Tan; Daoxin Xie; Chuanqing Sun

    2011-01-01

    Tiller number and culm length are important components of plant architecture and determinate grain production in rice.A line SIL046,derived from an introgression lines population developed by an accession of common wild rice (Oryza rufipogon Griff.) and a high-yielding indica cultivar Guichao 2 (Oryza sativa L.).exhibits a higher tiller number and shorter culm length phenotype than the recipient parent Guichao 2 (GC2).Genetic analysis showed that the high-tillering dwarf phenotype was controlled by a novel single recessive gene,referred to as the high-tillering dwarf3 (htd3),which located within the genetic distance of 13.4 cM between SSR makers RM7003 and RM277 on chromosome 12.By means of fine-mapping strategy,we mapped HTD3 gene within the genetic distance of 2.5 cM and the physical distance of 3100 kb in the centromere of chromosome 12.Further identification of HTD3 gene would provide a new opportunity to uncover the molecular mechanism of the development of culm and tiller,two important components of yields in rice.

  8. Blast resistant gene on rice mutant R917 and it translation

    R917 is a new rice variety with strong blast disease resistance. The resistance genes of R917 and its parents, Chengte 232 and Xiushui 37, were analysed with blast races of Pyricularia oryzae ZB13, ZC15 and ZE3. The results showed that only one dominant gene controlled the resistance to the three blast races in R917. Allelism test indicated that the resistant gene of R917 was non-allelic with its parents. The blast resistance was tested by inoculating with 7 Japanese strains. R917 was highly resistant to the all. The allelism test also indicated that the resistant gene of R917 was non-allelic with Toride 1. The reaction with some strains between R917 and Toride 1 indicated that the blast resistant gene of R917 is different with the 14 genes that was reported in Japan. The identification of the disease resistance for the progenies of R917 crosses with XS861 showed that R917 could be used as a good material for resistance to rice blast in rice breeding

  9. In planta assay of hygromycin susceptibility and mutant screening in rice at heading stage

    Cells and tissue of plants carrying the hygromycin phosphotransferase gene (HPT) are tolerant to antibiotic hygromycin and hence become the common selection gene for genetic transformation of crop plants, particularly monocots. The present study aimed at establishing a rapid method for in planta screening of hygromycin tolerant plants in transgenic breeding. At heading stage transgenic and conventional rice plants were sprayed with hygromycin solutions of different concentrations (25 ∼ 100 mg/L) and toxic symptoms were observed in the following days. It was observed that yellow-brown necrotic spots appeared in the leaves and grains of conventional rice varieties after foliar spraying of 50 mg/L hygromycin, and the more spots were occurred with the higher hygromycin solution. There were 21.1 and 19.2 spots per cm2 on flag leaves of indica varieties Jiayou 99 and C10, respectively; while 27.6% and 23.5% grains were yellow-brown in the varieties, respectively. The corresponding data for two japonica varieties Jiayou 5 and R5 were 11.8 and 10.7 for leave spots and 11.2% and 11.6% for yellow-brown grains, respectively. These results indicated that the two indica varieties are more sensitive to hygromycin than the two japonica varieties. In the treatment of hygromycin with above levels, the transgenic rice line KMD1 with the HPT gene showed no toxic symptoms on leaf or panicles. The γ-rays treated M2 population of KMD1 was sprayed with 100 mg/L hygromycin solution at heading stage and 42 plants were screened out with toxic symptoms in leaves and panicles form 120000 plants. Among the 42 hygromycin susceptible plants, 14 plants with leaves available for in vitro feeding assay were subjected to the feeding of rice striped steam borers [Chilo supperssalis (Walker)] and all showed high resistance. The above results showed that spraying of 100 mg/L hygromycin solution at heading stage would lead to visually apparent toxic symptoms in susceptibility rice plants and hence

  10. Accumulation of Mutant Neuroserpin Precedes Development of Clinical Symptoms in Familial Encephalopathy with Neuroserpin Inclusion Bodies

    Galliciotti, G; Glatzel, M; Kinter, J.; Kozlov, S V; Cinelli, P.; Rülicke, T; Sonderegger, P.

    2007-01-01

    Intracellular protein deposition due to aggregation caused by conformational alteration is the hallmark of a number of neurodegenerative disorders, including Parkinson's disease, tauopathies, Huntington's disease, and familial encephalopathy with neuroserpin inclusion bodies. The latter is an autosomal dominant disorder caused by point mutations in neuroserpin resulting in its destabilization. Mutant neuroserpin polymerizes and forms intracellular aggregates that eventually lead to neurodegen...

  11. Oxidation deoxidize metabolism in the rice altered lateral root mutant RM109

    The author reports the characteristics of a 2,4-D resistance mutant, altered lateral root, RM109, which is deficient in SDH (succinate dehydrogenase) activity. The SDH activity of RM109 was 60%-70% of that the wild type. Oochikara, roots is treated with reducer NADPH, NADH and FAD, the SDH activity of RM109 were lower than Oochikara. Genetic analysis in the F1 and F2 indicated that SDH activity in the mutant was transmitted by a single dominant nuclear gene. The observations of resistance to plant hormone, TIBA and H2O2 showed that the resistance to 2,4-D, NAA, TIBA and H2O2 with RM109 were 12,8,6 and 0.24 times of those with Oochikara, respectively. These results indicated that the mutant was deficient in oxidation deoxidize metabolism

  12. Studies on some agronomic and quality characteristics of 271 induced early mutants of rice (Oryza sativa L. cv. Nizersail)

    Nizersail, the most popular, recommended rice variety in Bangladesh, was subjected to gamma-irradiation (10 - 25 kR) or ethyl methane sulfonate (EMS) (0.75 - 1.50%) treatments to obtain the mutants with stiff straw and early maturity. In the M2 generation, 29 gamma-ray- and 8 EMS-induced mutants were selected mainly for short culm length and earliness. Further selections were made in the segregating M3 and M4 populations, and finally 400 plants with short culm length were obtained. These 400 selections were grown in M5 lines, and 271 of these lines were analyzed for several characters. Heading time had singificantly shifted towards earliness in 40 lines. Yield per plant, 1,000-kernel weight, the length/breadth ratio of kernels, alkali spreading index value (indicator of amylose content) and dye-binding capacity (indicator of protein content) were significantly higher than those in the mother variety in 10 - 30% of the lines examined. However, no positive correlation among these characters was observed. Significant negative correlations were observed between heading time and 1,000-kernel weight, and between yield per plant and dye-binding capacity. These results suggest that the early heading plants may produce fewer tillers with bolder seeds, and that high yielding types may not simultaneously show high protein content. (Kaihara, S.)

  13. Plant Hormone Resistance and Agronomic Characteristics of the MT10 Mutant in Rice

    2000-01-01

    The MT10 mutant plants had resistances to auxin. Under light and dark culture,the roots of MT10 seedlings had shown less lateral roots and short lateral roots. In soil ,MT10 seedlings had shown not only no changed agronomic characteristics but also no significant difference with WT.

  14. Detection of genetic variability in Basmati and non-Basmati rice varieties and their radiation induced mutants through random amplified polymorphic DNA (RAPD)

    Random Amplified Polymorphic DNA (RAPDs) markers were utilized to detect polymorphism between pure lines and commercially available Basmati rice varieties to assess variation which may be helpful in quality control and varietal identification (Basmati-370 and derived radiation induced mutants), differentiation of mutants and parents, and identification of RAPD markers co-segregating with important agronomic traits including plant height, days to flower and grain quality. Basmati varieties were distinguished from non-Basmati varieties with the help of five diagnostic markers which will be useful for detecting mixing of non-Basmati and Basmati rices, currently a serious marketing problem. Different Basmati cultivars were identified with the help of diagnostic RAPD markers which can be used in quality control as well as for ''fingerprinting'' of cultivars. Different radiation induced mutants were also successfully distinguished from the parents on the basis of variety specific and mutant specific markers which will be useful for varietal identification. In addition to this, other markers were also identified which can differentiate mutants from each other and are being, used for the fingerprinting of different mutants, particularly the dwarf mutants having similar appearance but different parentage. For identification of RAPD markers co-segregating with plant height and days to flower, 50 F2 plants and four F3 families were studied from a reciprocal cross made between Kashmir Basmati (tall and early) and Basmati-198 (dwarf and late). Segregating bands were observed within these populations, and indicating the possible use of RAPD markers for tagging gene(s) of agronomic importance in rice. (author)

  15. Accumulation in Infected Rice Leaves, Antifungal Activity and Detoxification by Fungus

    Morifumi Hasegawa; Ichiro Mitsuhara; Shigemi Seo; Kazunori Okada; Hisakazu Yamane; Takayoshi Iwai; Yuko Ohashi

    2014-01-01

    To understand the role of the rice flavonoid phytoalexin (PA) sakuranetin for blast resistance, the fungus-responsive characteristics were studied. Young rice leaves in a resistant line exhibited hypersensitive reaction (HR) within 3 days post inoculation (dpi) of a spore suspension, and an increase in sakuranetin was detected at 3 dpi, increasing to 4-fold at 4 dpi. In the susceptible line, increased sakuranetin was detected at 4 dpi, but not at 3 dpi, by which a large fungus mass has accum...

  16. Field performance of selected mutants of sorghum and rice. Field evaluation review

    Agricultural research conducted in Mali by the Institute Polytechnique Rural (IPR) and the Institute d'Economie Rural (IER), from improvement of sorghum and African rice (Oryza glaberrima) with some Agency support, resulted in several advanced generations of sorghum and African rice with improved characteristics, including high yield. Project MLI/5/014 aims at further supporting both institutions to advance these promising results, particularly by supporting multi-location field trials to select high yielding plant varieties, and by adding capability in tissue culture techniques for advanced mutation breeding as well as in the use of nuclear techniques in soil studies. The project was approved in 1995, as a model project and the current budget for the Agency's input amounts to $469,300 until 1997. The disbursements up to April 1996 amount to $168,991. The present mid-term evaluation aims at assessing the progress of the project towards its intended objectives and overall goal and the evaluation methodology applied was based on the Logical Framework Approach for project design. Figs, tabs

  17. Expression of OsSPY and 14-3-3 genes involved in plant height variations of ion-beam-induced KDML 105 rice mutants

    The culm length of two semidwarf rice mutants (PKOS1, HyKOS1) obtained from low-energy N-ion beam bombardments of dehusked Thai jasmine rice (Oryza sativa L. cv. KDML 105) seeds showed 25.7% and 21.5% height reductions and one spindly rice mutant (TKOS4) showed 21.4% increase in comparison with that of the KDML 105 control. A cDNA-RAPD analysis identified differential gene expression in internode tissues of the rice mutants. Two genes identified from the cDNA-RAPD were OsSPY and 14-3-3, possibly associated with stem height variations of the semidwarf and spindly mutants, respectively. The OsSPY gene encoded the SPY protein which is considered to be a negative regulator of gibberellin (GA). On the other hand, the 14-3-3 encoded a signaling protein which can bind and prevent the RSG (repression of shoot growth) protein function as a transcriptional repressor of the kaurene oxidase (KO) gene in the GA biosynthetic pathway. Expression analysis of OsSPY, 14-3-3, RSG, KO, and SLR1 was confirmed in rice internode tissues during the reproductive stage of the plants by semi-quantitative RT-PCR technique. The expression analysis showed a clear increase of the levels of OsSPY transcripts in PKOS1 and HyKOS1 tissue samples compared to that of the KDML 105 and TKOS4 samples at the age of 50–60 days which were at the ages of internode elongation. The 14-3-3 expression had the highest increase in the TKOS4 samples compared to those in KDML 105, PKOS1 and HyKOS1 samples. The expression analysis of RSG and KO showed an increase in TKOS4 samples compared to that of the KDML 105 and that of the two semidwarf mutants. These results indicate that changes of OsSPY and 14-3-3 expression could affect internode elongation and cause the phenotypic changes of semidwarf and spindly rice mutants, respectively.

  18. Evaluation of novel starch-deficient mutants of Chlorella sorokiniana for hyper-accumulation of lipids

    Vonlanthen, S.; Dauvillée, D.; Purton, S

    2015-01-01

    When green algae are exposed to physiological stresses such as nutrient deprivation, growth is arrested and the cells channel fixed carbon instead into storage compounds, accumulating first starch granules and then lipid bodies containing triacylglycerides. In recent years there has been significant interest in the commercial exploitation of algal lipids as a sustainable source of biodiesel. Since starch and lipid biosynthesis involves the same C3 precursor pool, it has been proposed that mut...

  19. IACUBA 28: rice mutant variety for irrigated areas with its cultural management

    The variety IACuba 28 was obtained by irradiation of seeds of the cultivar J 104, with 20 Gy of fast neutrons of 14 MeV in 1989. From 1990 to 1995 was conducted the selection, in order to reach the homocigosity in the mutant line J 104 N2- C4-4-5P1-3-1. This mutant, with the code number 3763, was included in the observational trials in 1996. In dry season 1996-1997 began the evaluation in multi location trials around the country. From 1999 to 2001 the new variety was evaluated in validation test in four different provinces. IACuba 28 has a semi dwarf type with high tillering ability and resistance to lodging. This variety possess high yield potential (yielded 0.7 t/ha and 0.5 t/ha in dry and wet season, respectively, over the parent), and showed resistance to tagosodes orizicolus Muir., Pyricularia grisea Sacc. and other diseases, as well as presented a better grain quality than the parent variety. The cultural management for the new variety was determined, including nitrogen fertilization, sowing density, moisture range to harvest, dormancy of the seeds and the milling technology

  20. Genetic analysis and mapping of rice (Oryza sativa L.)male-sterile (OsMS-L) mutant

    LIU Haisheng; HUANG Chaofeng; LUO Da; YUANG Zheng; LIU Jianhua; ZHANG Dabing; CHU Huangwei; LI Hui; WANG Hongmei; WEI Jiali; LI Na; DING Shuyan; HUANG Hai; MA Hong

    2005-01-01

    A rice male-sterile mutant OsMS-L of japonica cultivar 9522 background, was obtained in M4 population treated with 60Co γ-Ray. Genetic analysis indicated that the male-sterile phenotype was controlled by a single recessive gene. Results of tissue section showed that at microspore stage, OsMS-L tapetum was retarded. Then tapetal cells expanded and microspores degenerated. No matured pollens were observed in OsMS-L anther locus. To map OsMS-L locus, an F2 population was constructed from the cross between the OsMS-L (japonica) and LongTeFu B(indica). Firstly, the OsMS-L locus was roughly mapped between two SSR markers, RM109 and RM7562 on chromosome 2. And then eleven polymorphic markers were developed for further fine fine-mapping. At last the OsMS-L locus was mapped between the two InDel markers, Lhs10 and Lhs6 with genetic distance of 0.4 cM, respectively. The region was delimited to 133 kb. All these results were useful for further cloning and functional analysis of OsMS-L.

  1. Yield analysis in gamma ray induced advance generation mutants of short grain aromatic non-Basmati rice

    Yield analysis was made in a population comprising 18 advance generation (M4) morphologically distinct induced mutants along with their two mother genotypes, derived from Gobindabhog, a popular short grain aromatic non-basmati rice variety of West Bengal. The estimates of genotypic and phenotypic coefficients of variation were high for flag leaf angle; moderate for straw weight, harvest index, grain yield and flag leaf length; and low for days to flower, panicle length, plant height, panicle number, spikelet number, spikelet fertility (per cent), grain number, test weight. The estimates of heritability in broad sense were very high for days to flower, flag leaf angle, plant height, spikelet fertility per cent, test weight, flag leaf length and straw weight moderate for grain number, spikelet number, harvest index, grain yield and panicle length; and low for panicle number. The estimates of genetic advance as per cent of mean were high for flag leaf angle; moderate for straw weight and harvest index; and low for the remaining characters. The results of phenotypic and genotypic coefficients of variation, heritability and genetic advance revealed flag leaf angle, grain number, straw weight and grain yield per plant would be useful traits for selection

  2. Yield response of an erect, narrow and thick-leaved rice mutant and the derived strain to different planting densities

    The study was designed to investigate the possibility of mutation induction concerning leaf photosynthesis and canopy type, and to examine the yield performance of such a mutant at different planting densities. A semidwarf strain, G31, with narrow, erect and thick leaves, was selected after chronic γ-irradiation and hybridization. Net photosynthetic and transpiration rates per leaf area of this strain were found to be 1.5 times as high as the best available cultivar. In direct sowing of rice seeds, G31 had the highest grain yield in all levels of nitrogen top dressing, compared with the yields of the best available cultivars. Out of the progeny, after maize DNA treatment, of the G31 seeds a strain, L99, with a unique plant type was isolated. The tillering is less, the culms are taller and thicker, and the panicles are larger, compared with the parent G31. The agronomic performance of the L99 strain was tested with heavy nitrogen top dressing at different planting densities, along with other varieties. The yielding abilities were about the same in the best available cultivar when evaluated against the yield per day during their growth period. (author)

  3. Sulfur alleviates arsenic toxicity by reducing its accumulation and modulating proteome, amino acids and thiol metabolism in rice leaves

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Dwivedi, Sanjay; Deeba, Farah; Kumar, Smita; Suman, Shankar; Adhikari, Bijan; Shukla, Yogeshwar; Trivedi, Prabodh Kumar; Pandey, Vivek; Tripathi, Rudra Deo

    2015-11-01

    Arsenic (As) contamination of water is a global concern and rice consumption is the biggest dietary exposure to human posing carcinogenic risks, predominantly in Asia. Sulfur (S) is involved in di-sulfide linkage in many proteins and plays crucial role in As detoxification. Present study explores role of variable S supply on rice leaf proteome, its inclination towards amino acids (AA) profile and non protein thiols under arsenite exposure. Analysis of 282 detected proteins on 2-DE gel revealed 113 differentially expressed proteins, out of which 80 were identified by MALDI-TOF-TOF. The identified proteins were mostly involved in glycolysis, TCA cycle, AA biosynthesis, photosynthesis, protein metabolism, stress and energy metabolism. Among these, glycolytic enzymes play a major role in AA biosynthesis that leads to change in AAs profiling. Proteins of glycolytic pathway, photosynthesis and energy metabolism were also validated by western blot analysis. Conclusively S supplementation reduced the As accumulation in shoot positively skewed thiol metabolism and glycolysis towards AA accumulation under AsIII stress.

  4. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    Terry J. Rose

    2016-01-01

    Full Text Available Enhanced efficiency nitrogen (N fertilizers (EEFs may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP and polymer-coated urea (PCU to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key mineral nutrients. Plant growth and mineral accumulation and partitioning to grains did not differ significantly between plants fertilized with urea or urea-DMPP. In contrast, biomass accumulation and the accumulation of phosphorus, potassium, calcium, magnesium, copper, zinc and manganese were delayed during the early growth phase of plants fertilized with PCU. However, plants in the PCU treatment ultimately compensated for this by increasing growth and nutrient uptake during the latter vegetative stages so that no differences in biomass or nutrient accumulation generally existed among N fertilizer treatments at anthesis. Delayed biomass accumulation in rice fertilized with PCU does not appear to reduce the total accumulation of mineral nutrients, nor to have any impact on grain mineral nutrition when biomass and grain yields are equal to those of rice grown with urea or urea-DMPP.

  5. Accumulation and distribution of elements in rice (seed, brand layer, husk) by neutron activation analysis

    Various rice samples (seed, brand layer, husk) from Vietnam were analyzed for Se, Hg, Cr, Ni, Sc, Rb, Fe, Zn and Co by neutron activation analysis. The concentration values found (seed) were as follows: Se 0.04-0.07 ppm, Hg 0.02-0.07 ppm, Cr 2.13-8.65 ppm, Ni 1.56-4.95 ppm, Sc 0.02-0.06 ppm, Rb 0.84-2.71 ppm, Fe 26.31-96.07 ppm, Zn 10.65-27.39 ppm and Co 0.02-0.15 ppm. The values were reported in ppm (dry weight). Statistical analysis showed that the content of elements varies in different parts of rice; the content of Rb, Fe, Ni, Cr of husk was significantly higher than in seed and brand layer. (author) 12 refs.; 2 figs.; 1 tab

  6. Accumulation of methylmercury in rice and flooded soil in experiments with an enriched isotopic Hg(II) tracer

    Strickman, R. J.; Mitchell, C. P. J.

    2015-12-01

    Methylmercury (MeHg) is a neurotoxin produced in anoxic aquatic sediments. Numerous factors, including the presence of aquatic plants, alter the biogeochemistry of sediments, affecting the rate at which microorganisms transform bioavailable inorganic Hg (IHg) to MeHg. Methylmercury produced in flooded paddy soils and its transfer into rice has become an important dietary consideration. An improved understanding of how MeHg reaches the grain and the extent to which rice alters MeHg production in rhizosphere sediments could help to inform rice cultivation practices. We conducted a controlled greenhouse experiment with thirty rice plants grown in individual, flooded pots amended with enriched 200Hg. Unvegetated controls were maintained under identical conditions. At three plant growth stages (vegetative growth, flowering, and grain maturity), ten plants were sacrificed and samples collected from soil, roots, straw, panicle, and grain of vegetated and unvegetated pots, and assessed for MeHg and THg concentrations. We observed consistent ratios between ambient and tracer MeHg between soils (0.36 ±0.04 — 0.44 ± 0.09) and plant compartments (0.23 ± 0.07 -0.34 ± 0.05) indicating that plant MeHg contamination originates in the soil rather than in planta methylation. The majority of this MeHg was absorbed between the tillering (4.48 ± 2.38 ng/plant) and flowering (8.43 ± 5.12 ng/pl) phases, with a subsequent decline at maturity (2.87 ± 1.23 ng/pl) only partly explained by translocation to the developing grain, indicating that MeHg was demethylated in planta. In contrast, IHg was absorbed from both soil and air, as evidenced by the higher ambient IHg concentrations compared to tracer (3.76 ± 1.19 vs. 0.27 ± 0.40 ng/g). Surprisingly, MeHg accumulation was significantly (p= 0.042-- 0.003) lower in vegetated vs. unvegetated sediments at flowering (1.41 ± 0.26 vs. 1.57 ± 0.23) and maturity (1.27 ± 0.22 vs. 1.71 ± 0.25), suggesting that plant exudates bound Hg

  7. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice.

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-07-01

    Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings. PMID:25941326

  8. Effects of nitrogen fertilization strategies on nitrogen use efficiency in physiology, recovery, and agronomy and redistribution of dry matter accumulation and nitrogen accumulation in two typical rice cultivars in Zhejiang, China

    XIE Wen-xia; WANG Guang-huo; ZHANG Qi-chun; GUO Hai-chao

    2007-01-01

    Field experiments were conducted in farmers' rice fields in 2001 and 2002 to study the effects of nitrogen (N) management strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers'fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution(post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer's routine practice of Zhejiang.With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China.

  9. Mutant SOD1 accumulation in sensory neurons does not associate with endoplasmic reticulum stress features: Implications for differential vulnerability of sensory and motor neurons to SOD1 toxicity.

    Taiana, Michela; Sassone, Jenny; Lauria, Giuseppe

    2016-08-01

    Mutations in Cu/Zn-superoxide dismutase (SOD1) cause familial amyotrophic lateral sclerosis (ALS). Previous papers showed that mutant SOD1 accumulates and undergoes misfolding in motor neurons and that the specific interaction of mutant SOD1 with derlin-1 leads to endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). Because evidence shows that mutant SOD1 expression also damages sensory neurons, we hypothesized that, similarly to motor neurons, the sensory neurons of ALS mouse model SOD1(G93A) accumulate mutant/misfolded SOD1 and suffer from ER stress and UPR activation. Our results reveal that SOD1(G93A) sensory neurons accumulate mutant/misfolded SOD1 but, surprisingly, do not suffer from ER stress and UPR activation. Moreover, the sensory neurons do not express detectable levels of the SOD1 interactor derlin-1. These results suggest a potential molecular mechanism underlying the differential vulnerability of motor and sensory neurons to mutant SOD1 toxicity. PMID:27241719

  10. A loss-of-function allele of OsHMA3 associated with high cadmium accumulation in shoots and grain of Japonica rice cultivars.

    Yan, Jiali; Wang, Peitong; Wang, Peng; Yang, Meng; Lian, Xingming; Tang, Zhong; Huang, Chao-Feng; Salt, David E; Zhao, Fang Jie

    2016-09-01

    Excessive cadmium (Cd) accumulation in rice poses a risk to food safety. OsHMA3 plays an important role in restricting Cd translocation from roots to shoots. A non-functional allele of OsHMA3 has been reported in some Indica rice cultivars with high Cd accumulation, but it is not known if OsHMA3 allelic variation is associated with Cd accumulation in Japonica cultivars. In this study, we identified a Japonica cultivar with consistently high Cd accumulation in shoots and grain in both field and greenhouse experiments. The cultivar possesses an OsHMA3 allele with a predicted amino acid mutation at the 380(th) position from Ser to Arg. The haplotype had no Cd transport activity when the gene was expressed in yeast, and the allele did not complement a known nonfunctional allele of OsHMA3 in F1 test. The allele is present only in temperate Japonica cultivars among diversity panels of 1483 rice cultivars. Different cultivars possessing this allele showed greatly increased root-to-shoot Cd translocation and a shift in root Cd speciation from Cd-S to Cd-O bonding determined by synchrotron X-ray absorption spectroscopy. Our study has identified a new loss-of-function allele of OsHMA3 in Japonica rice cultivars leading to high Cd accumulation in shoots and grain. PMID:27038090

  11. Dynamic behavior of fallout strontium-90 in rice through production, distribution and consumption in relation to its accumulation in human bone

    A system dynamics model was proposed for investigating the dynamic behavior of fallout 90Sr through production, distribution and consumption of rice, the staple of Japanese food, and the long term accumulation in human bone. The calculated 90Sr contents in rice and human bone were compared with the environmental surveillance data to examine the validity of the model. The results obtained in this study under the limited assumptions are as follows: (1) The proposed model is promising for evaluating the long term behavior of fallout 90Sr in the environment although identification and determination of some environmental parameters should be improved. (2) The migration of fallout 90Sr into the deep soil layers with underground water is most significant among the several transfer pathways considered in the rice-plant field. (3) The influence of rice-crop distribution on the concentration of 90Sr in consumer rice is small. Fallout 90Sr is transported with rice generally from the coast of the Sea of Japan to those of Pacific Ocean. (4) The concentration of 90Sr in rice crops estimated by the proposed model may vary with a factor of 2.5 due to uncertainties in the environmental parameters. (author)

  12. Sulfur (S)-induced enhancement of iron plaque formation in the rhizosphere reduces arsenic accumulation in rice (Oryza sativa L.) seedlings

    The effects of two sulfur (S) sources (SO42-, S0), and three rates of S application (0, 30, 120 mg S/kg) on the formation of iron plaque in the rhizosphere, and on the root surface of rice, and As (arsenic) uptake into rice (Oryza sativa L.) were studied in a combined soil-sand culture experiment. Significant differences in As uptake into rice between +S and -S treatments were observed in relation to S sources, and rates of S application. Concentrations of As in rice shoots decreased with increasing rates of S application. The mechanism could be ascribed to sulfur, induced the formation of iron plaque, since concentrations of Fe in iron plaque on quartz sands in the rhizosphere, and on the root surface of rice increased with increasing rates of S application. The results suggest that sulfur fertilization may be important for the development approaches to reducing As accumulation in rice. - Sulfur-induced enhancement of iron plaque formation on the root surface of rice

  13. Comparative transcripts profiling reveals new insight into molecular processes regulating lycopene accumulation in a sweet orange (Citrus sinensis red-flesh mutant

    Zhang Jianchen

    2009-11-01

    Full Text Available Abstract Background Interest in lycopene metabolism and regulation is growing rapidly because accumulative studies have suggested an important role for lycopene in human health promotion. However, little is known about the molecular processes regulating lycopene accumulation in fruits other than tomato so far. Results On a spontaneous sweet orange bud mutant with abnormal lycopene accumulation in fruits and its wild type, comparative transcripts profiling was performed using Massively Parallel Signature Sequencing (MPSS. A total of 6,877,027 and 6,275,309 reliable signatures were obtained for the wild type (WT and the mutant (MT, respectively. Interpretation of the MPSS signatures revealed that the total number of transcribed gene in MT is 18,106, larger than that in WT 17,670, suggesting that newly initiated transcription occurs in the MT. Further comparison of the transcripts abundance between MT and WT revealed that 3,738 genes show more than two fold expression difference, and 582 genes are up- or down-regulated at 0.05% significance level by more than three fold difference. Functional assignments of the differentially expressed genes indicated that 26 reliable metabolic pathways are altered in the mutant; the most noticeable ones are carotenoid biosynthesis, photosynthesis, and citrate cycle. These data suggest that enhanced photosynthesis and partial impairment of lycopene downstream flux are critical for the formation of lycopene accumulation trait in the mutant. Conclusion This study provided a global picture of the gene expression changes in a sweet orange red-flesh mutant as compared to the wild type. Interpretation of the differentially expressed genes revealed new insight into the molecular processes regulating lycopene accumulation in the sweet orange red-flesh mutant.

  14. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    Terry J. Rose

    2016-01-01

    Enhanced efficiency nitrogen (N) fertilizers (EEFs) may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP) and polymer-coated urea (PCU) to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key minera...

  15. Selection for blast resistant mutants in radiation irradiated rice populations. Part of a coordinated programme on induced mutations for disease resistance in crop plants

    A newly released rice variety, Tongil, has many desirable agronomic characters and a particularly high resistance to blast disease. However, it may become susceptible in the future, since a resistant variety released for field planting often encounters the creation of new races of blast fungus. This study was undertaken to identify potential blast-resistant mutants from the population of the irradiated variety, Tongil, by inoculating these materials with induced mutant races of blast fungus which are likely to occur in the future. Blast conidia were irradiated with X-rays and the virulent mutants were identified according to their ability to infect Tongil. Seven blast-resistant mutant lines from the Pungkwang variety, selected through the uplands blast nursery test, were likewise outstanding in resistance in the field compared with the parent. Ten resistant lines from the variety Tongil, identified by artificial inoculation with the mutant race IA-67, were also selected. The results in the study of resistance inheritance showed that blast resistance was conditioned by a single dominant gene and the Tongil variety has three or more resistant genes

  16. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season

    CH4 emission from rice paddy soil. • N2O emission was decreased instead of applying N-rich cover crops. • N was accumulated mainly in smaller soil aggregates during rice cultivation. • N accumulation increased N2O emission potentials of soil aggregates. • Higher amount of N2O was emitted in the fallow season from cover crop treated soil

  17. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season

    Pramanik, Prabhat, E-mail: prabhat2003@gmail.com; Haque, Md. Mozammel; Kim, Sang Yoon; Kim, Pil Joo, E-mail: pjkim@gnu.ac.kr

    2014-08-15

    considered especially for fallow season to calculate total GWP. - Highlights: • Cover crop application increased CH{sub 4} emission from rice paddy soil. • N{sub 2}O emission was decreased instead of applying N-rich cover crops. • N was accumulated mainly in smaller soil aggregates during rice cultivation. • N accumulation increased N{sub 2}O emission potentials of soil aggregates. • Higher amount of N{sub 2}O was emitted in the fallow season from cover crop treated soil.

  18. Effects of tire rubber ash and zinc sulfate on crop productivity and cadmium accumulation in five rice cultivars under field conditions.

    Fahad, Shah; Hussain, Saddam; Khan, Fahad; Wu, Chao; Saud, Shah; Hassan, Shah; Ahmad, Naeem; Gang, Deng; Ullah, Abid; Huang, Jianliang

    2015-08-01

    Cadmium (Cd) is among the most widespread and toxic heavy metals becoming a severe threat to humans. A field study was conducted to examine the role of various zinc (Zn) fertilization treatments and cultivars on crop productivity and Zn and Cd concentrations in brown rice and rice straw. The Zn fertilization treatments included an unfertilized control, foliar applied Zn sulfate (ZnSO4) at panicle initiation stage, foliar applied ZnSO4 at milky stage, soil application of rubber ash, and soil-applied ZnSO4, while five rice cultivars were Swat-1, Shadab, Shua-92, Swat-2, and Sada Hayat. All the Zn fertilization treatments resulted in significantly higher number of panicles, number of spikelets per panicles, spikelet fertility, 1,000-grain weight, grain yield, brown rice and rice straw Zn concentrations, and significantly lower Cd concentrations. Soil application of rubber ash remained the best among all Zn fertilization treatments as it resulted in 73% higher grain yield and reduced Cd concentration by 51% as compared with control. Variations were also apparent among cultivars, and Shua-92 and Swat-2 performed better in terms of all studied attributes as compared with other cultivars. Conclusively, cultivar selection and Zn application are effective strategies to improve rice grain yield as well as quality. Rubber ash appeared a viable source of Zn having the ability to increase yield along with reducing Cd accumulation. PMID:25903182

  19. Effects of Ratio of Row Spacing to lntrarow Spacing on Yield and Nitrogen Accumulation and Utilization of Early and Late Rice

    Chengchun YANG; Hongxin LlN; Zhanqi YUAN; Yunping XlAO; Rengen LlU

    2015-01-01

    Objective] The aim was to provide a theoretical basis for the rational configuration of ratio of row spacing to intrarow spacing (RS/lS) of double-cropping rice. [Methods] With early rice ‘Ganxin 203’ and ‘Zhongjiazao 17’ and late rice‘Ganxin 688’ and ‘WufengyouT025’ as materials, the effects of RS/lS on yield, ni-trogen accumulation and utilization were studied in the same planting density of 31.20×104 hil s/hm2. [Results] The results showed that yield of early rice was higher in RS/lS2.8 (30.0 cm × 10.7 cm) and RS/lS2.0 (25.0 cm × 12.8 cm) treatment, and low-er in RS/lS5.0 (40.0 cm × 8.0 cm) and RS/lS1.3 (20.0 cm × 16.0 cm) treatment, while late rice were higher in RS/lS5.0 and RS/lS2.0 treatment, and lower in RS/lS2.8 and RS/lS1.3 treatment. Total nitrogen accumulation and apparent utilization ratio of nitro-gen of early rice were higher in RS/lS2.0 treatment and lower in RS/lS5.0 treatment, while, for late rice were higher in RS/lS2.8 treatment and lower in RS/lS5.0 treatment. Nitrogen requirement for 100 kg grain production of early rice was higher in RS/lS1.3 treatment and lower in RS/lS2.0 treatment, while, for late rice were higher in RS/lS2.8 treatment, lower in RS/lS5.0 treatment. [Conclusion] ln sum, 4 varieties of early and late rice obtained higher yield in 25.0 cm × 12.8 cm and lower yield in 20.0 cm × 16.0 cm, and total nitrogen accumulation, nitrogen requirement for 100 kg grain production and apparent utilization ratio of nitrogen were al lower in 40.0 cm × 8.0 cm.

  20. Activity, reconstitution, and accumulation of nitrogenase components in Azotobacter vinelandii mutant strains containing defined deletions within the nitrogenase structural gene cluster.

    Robinson, A. C.; Burgess, B. K.; Dean, D R

    1986-01-01

    The Azotobacter vinelandii genes encoding the nitrogenase structural components are clustered and ordered: nifH (Fe protein)-nifD (MoFe protein alpha subunit)-nifK (MoFe protein beta subunit). In this study various A. vinelandii mutant strains which contain defined deletions within the nitrogenase structural genes were isolated and studied. Mutants deleted for the nifD or nifK genes were still able to accumulate significant amounts of the unaltered MoFe protein subunit as well as active Fe pr...

  1. Homologous series of induced early mutants in Indica rice. Pt.3: The relationship between the induction of homologous series of early mutants and its different pedigree

    The percentage of homologous series of early mutants (PHSEM) induced by irradiation was closely related to its pedigree. This study showed that PHSEM for varieties with the same pedigree were similar, and there were three different level of dominance (high, low and normal) in the homologous series induced from different pedigree. The PHSEM for varieties derived form distant-relative-parents were higher than that derived from close-relative-parents. There was the dominance pedigree for the induction of homologous series of early mutants. IR8(Peta x DGWG), IR127 (Cpslo x Sigadis) and IR24 (IR8 x IR127) were dominant pedigree, and varieties derived from them could be easily induced the homologous series of early mutants

  2. High level accumulation of soluble diphtheria toxin mutant (CRM197) with co-expression of chaperones in recombinant Escherichia coli.

    Mahamad, Pornpimol; Boonchird, Chuenchit; Panbangred, Watanalai

    2016-07-01

    CRM197 is the diphtheria toxin mutant used in many conjugate vaccines. A fusion CRM197 (fCRM197) containing all the tags conferred by the pET32a vector was produced as a soluble protein in Escherichia coli co-expressing several chaperone proteins in conjunction with low temperature cultivation. Trigger factor (Tf) enhanced formation of soluble fCRM197 (150.69 ± 8.95 μg/mL) to a greater degree than other chaperones when fCRM197 expression was induced at 25 °C for 12 h. However, prolonged cultivation resulted in a progressive reduction of fCRM197 accumulation. In contrast, at 15 °C cells, with or without Tf, fCRM197 accumulated to the highest level at 48 h (153.70 ± 13.14 μg/mL and 150.07 ± 8.13 μg/mL, respectively). Transmission electron microscopy (TEM) demonstrated that the formation of inclusion protein as well as cell lysis was reduced in cultures grown at 15 °C. Cell viability was substantially reduced in cells expressing Tf, compared to cultures without Tf, when fCRM197 was induced at 25 °C. The viability of Tf-expressing cells was enhanced when cultured at 15 °C. Both purified fCRM197 and CRM197 efficiently digested lambda DNA (λDNA) at 37 °C (92.78 and 97.45 %, respectively). Digestion efficiency of fCRM197 and CRM197 was reduced at 25 °C (80.80 and 62.73 %, respectively) and at 15 °C (7.34 and 24.79 %, respectively). These results demonstrating nuclease activity, enhanced cell lysis, and reduced cell viability are consistent with the finding of lower fCRM197 yield when cultivation and induction times were prolonged at 25 °C. The present work provides a procedure for the high-level production of soluble fCRM197 using E. coli as a heterologous host. PMID:27020286

  3. Evolving of mutant lines resistant to lodging, blast, and high yield in rice by induce mutation using gamma ray (physical mutagen)

    Induction of mutation for the purpose of producing variations in the gene pool has been used in recent years. In this experiment the locally adapted rice C V Moosa-Tarom was used as a high quality, tall and very lodging susceptible mutation material. The main purpose of this project was to evolve lodging resistant mutants of high yielding. The elite seeds of Moosa-Tarom variety after moisture regulation were exposed to 100, 200 and 300 Gy from Cobalt 60 source at the Nuclear Research Center. The irradiated seeds were sown in the field along with a comparable number of unirradiated seeds taken as control. All the first panicles of M1 plants were individually harvested and classified according to the dose rate as M2 material . Among M2 plant populations 203 plants that appeared from the agronomic point of view, along with a number of on unirradiated seeds, were selected and moved to the next generations. During subsequent screening for three generations (M 3-M 5) and due to lodging resistant, height and efficient factors of yield potential some mutant lines were harvested. From these lines in a preliminary and advanced randomized complete design agronomic traits, 13 promising lines were selected. From the experiment, line 43-3 were confirmed, which is characterized by lodging resistant and high yield. This line showed relative superiority and introduced to Rice Research Institute

  4. Mutants induced in rice (Oryza sativa L.) for the study of their reaction to Sclerotium oryzae Catt. and Sclerotium hydrophilum Sacc

    A series of families selected from the progeny of rice of the Arlesienne variety - from the National Institute for Agricultural Research (INRA) - after mutagenic treatment was studied with regard to their reaction to artificial infection by two types of pathogenic cryptogam which are found in France and which cause sclerotial diseases in rice. The mutagenic treatment was carried out in 1970, at the Montpellier Plant Improvement Station, with gamma rays from a cobalt source provided by the French Commissariat a l'energie atomique. The aim was to improve the Arlesienne variety, which, although of excellent quality for culinary purposes, was difficult to thresh (excessive resistance to extraction of kernels from husks) and to handle in the mill (pronounced villosity). Screening, done in 1971, and consecutive selection produced mutants which did not entail these difficulties; 28 families (M6 in 1975) were finally chosen for their superiority to the control. The Plant Biology and Pathology Laboratory at Montpellier has analysed the extent to which these mutants would be resistant in the event of an epidemic of Sclerotium. Eight families exhibited low or very low overall susceptibility to S. oryzae, 21 to S. hydrophilum and seven to both at once. From the practical point of view, four families are clearly superior to the Arlesienne control, one of them possessing great agronomic value. Several families proved to be less resistant than the parent variety, which confirms the mutation direction symmetry rule. (author)

  5. Molecular insights into how a deficiency of amylose affects carbon allocation – carbohydrate and oil analyses and gene expression profiling in the seeds of a rice waxy mutant

    Zhang Ming-Zhou

    2012-12-01

    Full Text Available Abstract Background Understanding carbon partitioning in cereal seeds is of critical importance to develop cereal crops with enhanced starch yields for food security and for producing specified end-products high in amylose, β-glucan, or fructan, such as functional foods or oils for biofuel applications. Waxy mutants of cereals have a high content of amylopectin and have been well characterized. However, the allocation of carbon to other components, such as β-glucan and oils, and the regulation of the altered carbon distribution to amylopectin in a waxy mutant are poorly understood. In this study, we used a rice mutant, GM077, with a low content of amylose to gain molecular insight into how a deficiency of amylose affects carbon allocation to other end products and to amylopectin. We used carbohydrate analysis, subtractive cDNA libraries, and qPCR to identify candidate genes potentially responsible for the changes in carbon allocation in GM077 seeds. Results Carbohydrate analysis indicated that the content of amylose in GM077 seeds was significantly reduced, while that of amylopectin significantly rose as compared to the wild type BP034. The content of glucose, sucrose, total starch, cell-wall polysaccharides and oil were only slightly affected in the mutant as compared to the wild type. Suppression subtractive hybridization (SSH experiments generated 116 unigenes in the mutant on the wild-type background. Among the 116 unigenes, three, AGP, ISA1 and SUSIBA2-like, were found to be directly involved in amylopectin synthesis, indicating their possible roles in redirecting carbon flux from amylose to amylopectin. A bioinformatics analysis of the putative SUSIBA2-like binding elements in the promoter regions of the upregulated genes indicated that the SUSIBA2-like transcription factor may be instrumental in promoting the carbon reallocation from amylose to amylopectin. Conclusion Analyses of carbohydrate and oil fractions and gene expression

  6. Response of Rice to Insect Elicitors and the Role of OsJAR1 in Wound and Herbivory-Induced JA-IIe Accumulation

    Kaori Fukumoto; Kabir Md Alamgir; Yuko Yamashita; Izumi C.Mori; Hideyuki Matsuura; Ivan Galis

    2013-01-01

    Plants produce jasmonic acid (JA) and its amino acid conjugate,jasmonoyI-L-isoleucine (JA-IIe) as major defense signals in response to wounding and herbivory.In rice (Oryza sativa),JA and JA-IIe rapidly increased after mechanical damage,and this increase was further amplified when the wounds were treated with oral secretions from generalist herbivore larvae,lawn armyworms (Spodoptera mauritia),revealing for the first time active perception mechanisms of herbivore-associated elicitor(s) in rice.In the rice genome,two OsJAR genes can conjugate JA and IIe and form JA-IIe in vitro; however,their function in herbivoryinduced accumulation of JA-IIe has not been investigated.By functional characterization of TOS17 retrotrensposon-tagged Osjar1 plants and their response to simulated herbivory,we show that OsJAR1 is essential for JA-IIe production in herbivore-attacked,field-grown plants.In addition,OsJAR1 was required for normal seed development in rice under field conditions.Our results suggest that OsJAR1 possesses at least two major functions in rice defense and development that cannot be complemented by the additional OsJAR2 gene function,although this gene previously showed overlapping enzyme activity in vitro.

  7. Effects of mannitol induced osmotic stress on proline accumulation, pigment degradation, photosynthetic abilities and growth characters in C3 rice and C4 sorghum

    Suriyan CHA-UM; Souvanh THADAVONG; Chalermpol KIRDMANEE

    2009-01-01

    Osmotic stress is one of the most important abiotic factors which inhibit growth and development in both the vegetative and reproductive stages of many plant species. The aim of this investigation was to compare the biochemical and physiological responses in C3 rice and C4 sorghum to water deficit. Chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (TC) and total carotenoid (Cx+c) contents in both rice and sorghum seedlings under osmotic stress were adversely affected, related to increasing osmotic pressure in the culture media. In addition, the chlorophyll's fluorescence parameters and net photosynthetic rate (Pn) decreased, leading to growth reduction. Also, a positive correlation was found between physiological and biochemical data, while proline accumulation showed a negative relationship. The Chlb, Pn and fresh weight were maintained better in osmotic-stressed (-1.205 MPa) C4 sorghum seedlings than those in C3 rice seedlings. The growth and physiological responses of C3 rice and C4 sorghum decreased depending on the plant species, the osmotic pressure in the media and their interactions. Pigment content and Pn ability in C4 sorghum grown under mannitol-induced osmotic stress increased to a greater degree than in C3 rice, resulting in maintenance of growth.

  8. ABA biosynthesis defective mutants reduce some free amino acids accumulation under drought stress in tomato leaves in comparison with Arabidopsis plants tissues

    Adnan Ali Al.Asbahi

    2012-05-01

    Full Text Available The ability of plants to tolerate drought conditions is crucial for plant survival and crop production worldwide. The present data confirm previous findings reported existence of a strong relation between abscisic acid (ABA content and amino acid accumulation as response water stress which is one of the most important defense mechanism activated during water stress in many plant species. Therefore, free amino acids were measured to determine any changes in the metabolite pool in relation to ABA content. The ABA defective mutants of Arabidopsis plants were subjected to leaf dehydration for Arabidopsis on Whatman 3 mm filter paper at room temperature while, tomato mutant plants were subjected to drought stresses for tomato plants by withholding water. To understand the signal transduction mechanisms underlying osmotic stress-regulating gene induction and activation of osmoprotectant free amino acid synthesizing genes, we carried out a genetic screen to isolate Arabidopsis mutants defective in ABA biosynthesis under drought stress conditions. The present results revealed an accumulation of specific free amino acid in water stressed tissues in which majority of free amino acids are increased especially those playing an osmoprotectant role such as proline and glycine. Drought stress related Amino acids contents are significantly reduced in the mutants under water stress condition while they are increased significantly in the wild types plants. The exhibited higher accumulation of other amino acids under stressed condition in the mutant plants suggest that, their expressions are regulated in an ABA independent pathways. In addition, free amino acids content changes during water stress condition suggest their contribution in drought toleration as common compatible osmolytes.

  9. Transcriptome Analysis of Differentially Expressed Genes Involved in Proanthocyanidin Accumulation in the Rhizomes of Fagopyrum dibotrys and an Irradiation-Induced Mutant

    Chen, Caixia; Li, Ailian

    2016-01-01

    The rhizome of Fagopyrum dibotrys is a traditional Chinese medicine that has recently gained attention due to substantial findings regarding its bioactive proanthocyanidin (PA) compounds. However, the molecular mechanism underlying PA accumulation in F. dibotrys remains elusive. We previously obtained an irradiation-induced mutant (RM_R) of F. dibotrys that had a higher PA content compared to that of the wild-type (CK_R). The present study aimed to elucidate the molecular mechanism underlying...

  10. Rice PROTEIN l-ISOASPARTYL METHYLTRANSFERASE isoforms differentially accumulate during seed maturation to restrict deleterious isoAsp and reactive oxygen species accumulation and are implicated in seed vigor and longevity.

    Petla, Bhanu Prakash; Kamble, Nitin Uttam; Kumar, Meenu; Verma, Pooja; Ghosh, Shraboni; Singh, Ajeet; Rao, Venkateswara; Salvi, Prafull; Kaur, Harmeet; Saxena, Saurabh Chandra; Majee, Manoj

    2016-07-01

    PROTEIN l-ISOASPARTYL O-METHYLTRANSFERASE (PIMT) is a protein-repairing enzyme involved in seed vigor and longevity. However, the regulation of PIMT isoforms during seed development and the mechanism of PIMT-mediated improvement of seed vigor and longevity are largely unknown. In this study in rice (Oryza sativa), we demonstrate the dynamics and correlation of isoaspartyl (isoAsp)-repairing demands and PIMT activity, and their implications, during seed development, germination and aging, through biochemical, molecular and genetic studies. Molecular and biochemical analyses revealed that rice possesses various biochemically active and inactive PIMT isoforms. Transcript and western blot analyses clearly showed the seed development stage and tissue-specific accumulation of active isoforms. Immunolocalization studies revealed distinct isoform expression in embryo and aleurone layers. Further analyses of transgenic lines for each OsPIMT isoform revealed a clear role in the restriction of deleterious isoAsp and age-induced reactive oxygen species (ROS) accumulation to improve seed vigor and longevity. Collectively, our data suggest that a PIMT-mediated, protein repair mechanism is initiated during seed development in rice, with each isoform playing a distinct, yet coordinated, role. Our results also raise the intriguing possibility that PIMT repairs antioxidative enzymes and proteins which restrict ROS accumulation, lipid peroxidation, etc. in seed, particularly during aging, thus contributing to seed vigor and longevity. PMID:26987457

  11. Carbon, Nitrogen and Phosphorus Accumulation and Partitioning, and C:N:P Stoichiometry in Late-Season Rice under Different Water and Nitrogen Managements

    Yushi Ye; Xinqiang Liang; Yingxu Chen; Liang Li; Yuanjing Ji; Chunyan Zhu

    2014-01-01

    Water and nitrogen availability plays an important role in the biogeochemical cycles of essential elements, such as carbon (C), nitrogen (N) and phosphorus (P), in agricultural ecosystems. In this study, we investigated the seasonal changes of C, N and P concentrations, accumulation, partitioning, and C:N:P stoichiometric ratios in different plant tissues (root, stem-leaf, and panicle) of late-season rice under two irrigation regimes (continuous flooding, CF; alternate wetting and drying, AWD...

  12. Characterization of singlet oxygen-accumulating mutants isolated in a screen for altered oxidative stress response in Chlamydomonas reinhardtii

    Eggen Rik IL

    2010-12-01

    Full Text Available Abstract Background When photosynthetic organisms are exposed to harsh environmental conditions such as high light intensities or cold stress, the production of reactive oxygen species like singlet oxygen is stimulated in the chloroplast. In Chlamydomonas reinhardtii singlet oxygen was shown to act as a specific signal inducing the expression of the nuclear glutathione peroxidase gene GPXH/GPX5 during high light stress, but little is known about the cellular mechanisms involved in this response. To investigate components affecting singlet oxygen signaling in C. reinhardtii, a mutant screen was performed. Results Mutants with altered GPXH response were isolated from UV-mutagenized cells containing a GPXH-arylsulfatase reporter gene construct. Out of 5500 clones tested, no mutant deficient in GPXH induction was isolated, whereas several clones showed constitutive high GPXH expression under normal light conditions. Many of these GPXH overexpressor (gox mutants exhibited higher resistance to oxidative stress conditions whereas others were sensitive to high light intensities. Interestingly, most gox mutants produced increased singlet oxygen levels correlating with high GPXH expression. Furthermore, different patterns of altered photoprotective parameters like non-photochemical quenching, carotenoid contents and α-tocopherol levels were detected in the various gox mutants. Conclusions Screening for mutants with altered GPXH expression resulted in the isolation of many gox mutants with increased singlet oxygen production, showing the relevance of controlling the production of this ROS in photosynthetic organisms. Phenotypic characterization of these gox mutants indicated that the mutations might lead to either stimulated triplet chlorophyll and singlet oxygen formation or reduced detoxification of singlet oxygen in the chloroplast. Furthermore, changes in multiple protection mechanisms might be responsible for high singlet oxygen formation and GPXH

  13. Screening of Rice Cultivars with High Cadmium Accumulation and Its Cadmium Accumulation Characteristics%水稻镉高积累材料的筛选及其镉积累特征研究

    唐皓; 李廷轩; 张锡洲; 余海英; 陈光登

    2015-01-01

    Abstact:With the development of agriculture and industry, a large number of pollutants containing cadmium turning into the soil. It is important to screen the rice cultivars with high-Cd accumulation and study to its accumulating characteristics. Field experiment was conducted to investigate the differences of 56 rice parent materials on Cd accumulation characteristics under pollution paddy field. High-Cd accumulation rice cultivars were screened by the Cd content and shoot biomass, then analyzed its accumulation characteristics. (1) There were significant differences in the Cd content and Cd accumulation for rice cultivars at tillering stage (CV=44.05% and CV=50.21%) and booting stage (CV=23.57% and CV=28.62%) among the 56 rice cultivars when the Cd concentration of soil was 13.89 mg·kg-1. (2) The 56 rice cultivars were classified into tree type: high Cd accumulation type, mean Cd accumulation type and low Cd accumulation type. (3) The shoots and whole plants biomass of high Cd accumulation type were significantly higher than mean Cd accumulation type at tillering and booting stages. Then, the shoots and whole plants biomass of high Cd accumulation type reached 835.66and 994.59 g·m-2 which was higher than mean Cd accumulation type. The Cd accumulation in shoots were significantly higher than mean Cd accumulation type and low Cd accumulation type at booting stage. Meanwhile, the Cd accumulation in whole plants were significantly higher than mean Cd accumulation type and low Cd accumulation type at tillering and booting stage. (4) The Cd bioaccumulation coefficient and translation coefficient of high Cd accumulation type were significantly higher than mean Cd accumulation type and low Cd accumulation type at booting stage. These results suggested that high Cd accumulation type (GR Lu 17/548//Lu 17_9, GR548/Ming 63//527_1, GR Lu 17/IRBN95-199_1, GR Lu 17/548//Lu 17_7, GR Lu 17/IRBN92-332//Lu 17_1, GR Lu 17/548//Lu 17_3, GR Lu 17/IRBN92-332//527_8) were typical Cd

  14. Preliminary studies on the application of mutagens and in-vitro techniques to rice seeds for inducing salt tolerant mutants

    The mature seeds of four rice varieties were used as explants in this study. Dehulled rice seeds were treated with gamma-rays irradiation and sodium azide either in combined way or alone. Calli derived from ''IR28'' and ''Zhenshen 97 B'' were also irradiated with gamma-rays. The results showed that the callus induction rate and callus growth rate were seriously inhibited when the seeds had been exposed to 15 kR gamma-rays, 1 mM sodium azide (SA) had some stimulative effects on these two parameters. It also indicated that the plantlet regeneration frequency decreased while all the mutagenic treatments employed. The callus growth rate and plantlet regeneration frequency decreased with the increasing of NaCl content in salt enriched selective medium. The concentration of 1% NaCl (W/V) in medium is considered as optimal stress level to identify and isolate salt tolerant callus lines. These lines maintained their capacity of plant regeneration. The optimal radiation dosage for treating callus derived from rice seeds ranges 500-750R

  15. Lack of interleukin-1 type 1 receptor enhances the accumulation of mutant huntingtin in the striatum and exacerbates the neurological phenotypes of Huntington's disease mice

    Wang Chuan-En

    2010-11-01

    Full Text Available Abstract Huntington's disease results from expansion of a glutamine repeat (>36 glutamines in the N-terminal region of huntingtin (htt and is characterized by preferential neurodegeneration in the striatum of the brain. N171-82Q mice that express N-terminal 171 amino acids of htt with an 82-glutamine repeat show severe neurological phenotypes and die early, suggesting that N-terminal mutant htt is pathogenic. In addition, various cellular factors and genetic modifiers are found to modulate the cytotoxicity of mutant htt. Understanding the contribution of these factors to HD pathogenesis will help identify therapeutics for this disease. To investigate the role of interleukin type 1 (IL-1, a cytokine that has been implicated in various neurological diseases, in HD neurological symptoms, we crossed N171-82Q mice to type I IL-1 receptor (IL-1RI knockout mice. Mice lacking IL-1RI and expressing N171-82Q show more severe neurological symptoms than N171-82Q or IL-1RI knockout mice, suggesting that lack of IL-1RI can promote the neuronal toxicity of mutant htt. Lack of IL-1RI also increases the accumulation of transgenic mutant htt in the striatum in N171-82Q mice. Since IL-1RI signaling mediates both toxic and protective effects on neurons, its basal function and protective effects may be important for preventing the neuropathology seen in HD.

  16. Field performance of thirty mutant lines of the rice (Oryza sativa L.) varieties ICTA-Virginia and Precoz-ICTA

    Fifteen mutant lines from the variety ICTA-Virginia and fifteen from the variety Precozicta were evaluated according to their agronomic characteristics under conditions of the Motagua river valley during 1992. The objective was to select genotypes showing resistance to disease caused by Pyricularia grisea. The analysis of variance did not show significative differences among ICTA-Virginia mutants. The highest yield was form MV-860, 8.17 TM/ha and the lowest 5.31 TM/ha for MV-411. Significant differences were found among mutant lines from Precozicta. The highest yields were 6.06, 5.80 and 5.52 TM/ha for MPI-1189, MPI-1664 and MPI-1346 respectively. Inoculation with Pyricularia was made spraying it over the crop. However, it was not possible the evaluation of the disease in the neck (neck blast) due to absence of the pathogen. 5 tabs.(Author)

  17. Recent Progress on Rice Genetics in China

    Hua Jiang; Long-Biao Quo; Qian Qian

    2007-01-01

    Through thousands of years of evolution and cultivation, tremendously rich genetic diversity has been accumulated in rice (Oryza sativa L.), developing a large germplasm pool from which people can select varieties with morphologies of interest and other important agronomic traits. With the development of modern genetics, scientists have paid more attention to the genetic value of these elite varieties and germplasms, and such rich rice resources provide a good foundation for genetic research in China. Approximately 100 000 accessions of radiation-, chemical- or insertion-induced mutagenesis have been generated since the 1980s, and great progress has been made on rice molecular genetics. So far at least 16 variant/mutant genes including MOC1, BC1, SKC1, and Rf genes have been isolated and characterized in China. These achievements greatly promote the research on functional genomics, understanding the mechanism of plant development and molecular design breeding of rice in China. Here we review the progress of three aspects of rice genetics in China: moving forward at the molecular level, genetic research on elite varieties and germplasms, and new gene screening and genetic analysis using mutants. The prospects of rice genetics are also discussed.

  18. Transgenic rice seed expressing flavonoid biosynthetic genes accumulate glycosylated and/or acylated flavonoids in protein bodies

    Ogo, Yuko; Mori, Tetsuya; Nakabayashi, Ryo; Saito, Kazuki; Takaiwa, Fumio

    2015-01-01

    Highlight Glycosylated and/or acylated flavonoids in transgenic rice seeds were characterized by metabolome analysis, suggesting that ectopic expression of flavonoid biosynthetic enzymes can be used as a tool to expand their structural diversity.

  19. 水稻雄性半不育突变体的细胞学观察%Cytology Observation on the Male Semi-sterile Mutant of Rice

    彭苗苗; 陈发菊; 张德春

    2012-01-01

    TP-2 is a spontaneous semi-sterile mutant of TP309 which is a variety of rice ( Oryza satwa). The filaments of small flower are slender, the anthers are shriveled in white and transparent, the development of female organ is normal. Pollen viability shows that the pollen viability of mutant is 57.599% , much lower than that of control group (94. 177% ) , the pollen grains in TP-2 pollensac 436, much lower than that of control group (798). Paraffin section shows that the development from microspore mother cell to the end of meiosis on TP-2 mutant rice is normal, compared with the normal strains in the form. However, in the early microspore formation , rapid melting of tapetum, the process of microspore development lack of nutrition can not develop normally, resulting in a small dry spore. It has irregular shape, while some small spores have broken ablation phenomenon. May be the main reasons of abnormal development of small spores on TP-2 rice is the tapetum does not degrade normally. The observation provides basic material to mutant infertility of TP-2 and lays the foundation of TP-2.%TP-2是由水稻品种台北309自然突变的雄性半不育突变体.解剖小花后观察发现,突变体花药细长,干瘪,白色透明状,雌蕊正常.花粉活力检测结果表明:突变体水稻平均花粉粒活力率为57.599%,1个花粉囊里的花粉粒平均有436粒;正常材料台北309水稻平均花粉活力率为94.177%,1个花粉囊里的花粉粒有798粒.组织切片观察发现:突变体水稻从小孢子母细胞发育到减数分裂结束,和正常株相比较在形态上无显著差异,小孢子形成初期出现异常,绒毡层快速消融,小孢子在其发育过程中因得不到营养不能正常发育,产生的小孢子干瘪,呈不规则状,同时部分小孢子产生破裂消融现象,绒毡层不能正常降解可能是导致TP-2水稻小孢子异常发育的主要原因.通过以上观察,对进一步揭示TP-2突变体的不育机制提供了

  20. The alteration in the architecture of a T-DNA insertion rice mutant osmtd1 is caused by up-regulation of MicroRNA156f

    Qing Liu; and Langtao Xiao; Gezhi Shen; Keqin Peng; Zhigang Huang; Jianhua Tong; Mohammed Humayun Kabir; Jianhui Wang; Jingzhe Zhang; Genji Qin

    2015-01-01

    Plant architecture is an important factor for crop production. Some members of microRNA156 (miR156) and their target genes SQUAMOSA Promoter-Binding Protein-Like (SPL) were identified to play essential roles in the establish-ment of plant architecture. However, the roles and regulation of miR156 is not well understood yet. Here, we identified a T-DNA insertion mutant Osmtd1 (Oryza sativa multi-tillering and dwarf mutant). Osmtd1 produced more tillers and displayed short stature phenotype. We determined that the dramatic morphological changes were caused by a single T-DNA insertion in Osmtd1. Further analysis revealed that the T-DNA insertion was located in the gene Os08g34258 encoding a putative inhibitor I family protein. Os08g34258 was knocked out and OsmiR156f was significantly upregulated in Osmtd1. Overexpression of Os08g34258 in Osmtd1 com-plemented the defects of the mutant architecture, while overexpression of OsmiR156f in wild-type rice phenocopied Osmtd1. We showed that the expression of OsSPL3, OsSPL12, and OsSPL14 were significantly downregulated in Osmtd1 or OsmiR156f overexpressed lines, indicating that OsSPL3, OsSPL12, and OsSPL14 were possibly direct target genes of OsmiR156f. Our results suggested that OsmiR156f controlled plant architecture by mediating plant stature and tiller outgrowth and may be regulated by an unknown protease inhibitor I family protein.

  1. Hyper-accumulation of starch and oil in a Chlamydomonas mutant affected in a plant-specific DYRK kinase

    Schulz-Raffelt, Miriam; Chochois, Vincent; Auroy, Pascaline; Cuiné, Stéphan; Billon, Emmanuelle; Dauvillée, David; Li-Beisson, Yonghua; Peltier, Gilles

    2016-01-01

    Background Because of their high biomass productivity and their ability to accumulate high levels of energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production of biofuel. Accumulation of reserve compounds takes place when microalgae face adverse situations such as nutrient shortage, conditions which also provoke a stop in cell division, and down-regulation of photosynthesis. Despite growing interest in microalgal biofuels, little is kn...

  2. Production of superoxide from Photosystem II in a rice (Oryza sativa L.) mutant lacking PsbS

    Zulfugarov, Ismayil S; Tovuu, Altanzaya; Eu, Young-Jae; Dogsom, Bolormaa; Poudyal, Roshan Sharma; Nath, Krishna; Hall, Michael; Banerjee, Mainak; Yoon, Ung Chan; Moon, Yong-Hwan; An, Gynheung; Jansson, Stefan; Lee, Choon-Hwan

    2014-01-01

    Background PsbS is a 22-kDa Photosystem (PS) II protein involved in non-photochemical quenching (NPQ) of chlorophyll fluorescence. Rice (Oryza sativa L.) has two PsbS genes, PsbS1 and PsbS2. However, only inactivation of PsbS1, through a knockout (PsbS1-KO) or in RNAi transgenic plants, results in plants deficient in qE, the energy-dependent component of NPQ. Results In studies presented here, under fluctuating high light, growth of young seedlings lacking PsbS is retarded, and PSII in detach...

  3. Grb2 is regulated by foxd3 and has roles in preventing accumulation and aggregation of mutant huntingtin.

    Shounak Baksi

    Full Text Available Growth factor receptor protein binding protein 2 (Grb2 is known to be associated with intracellular growth and proliferation related signaling cascades. Huntingtin (Htt, a ubiquitously expressed protein, when mutated, forms toxic intracellular aggregates - the hallmark of Huntington's disease (HD. We observed an elevated expression of Grb2 in neuronal cells in animal and cell models of HD. Grb2 overexpression was predominantly regulated by the transcription factor Forkhead Box D3 (Foxd3. Exogenous expression of Grb2 also reduced aggregation of mutant Htt in Neuro2A cells. Grb2 is also known to interact with Htt, depending on epidermal growth factor receptor (EGFR activation. Grb2- mutant Htt interaction in the contrary, took place in vesicular structures, independent of EGFR activation that eventually merged with autophagosomes and activated the autophagy machinery helping in autophagosome and lysosome fusion. Grb2, with its emerging dual role, holds promise for a survival mechanism for HD.

  4. Citrate Accumulation-Related Gene Expression and/or Enzyme Activity Analysis Combined With Metabolomics Provide a Novel Insight for an Orange Mutant.

    Guo, Ling-Xia; Shi, Cai-Yun; Liu, Xiao; Ning, Dong-Yuan; Jing, Long-Fei; Yang, Huan; Liu, Yong-Zhong

    2016-01-01

    'Hong Anliu' (HAL, Citrus sinensis cv. Hong Anliu) is a bud mutant of 'Anliu' (AL), characterized by a comprehensive metabolite alteration, such as lower accumulation of citrate, high accumulation of lycopene and soluble sugars in fruit juice sacs. Due to carboxylic acid metabolism connects other metabolite biosynthesis and/or catabolism networks, we therefore focused analyzing citrate accumulation-related gene expression profiles and/or enzyme activities, along with metabolic fingerprinting between 'HAL' and 'AL'. Compared with 'AL', the transcript levels of citrate biosynthesis- and utilization-related genes and/or the activities of their respective enzymes such as citrate synthase, cytosol aconitase and ATP-citrate lyase were significantly higher in 'HAL'. Nevertheless, the mitochondrial aconitase activity, the gene transcript levels of proton pumps, including vacuolar H(+)-ATPase, vacuolar H(+)-PPase, and the juice sac-predominant p-type proton pump gene (CsPH8) were significantly lower in 'HAL'. These results implied that 'HAL' has higher abilities for citrate biosynthesis and utilization, but lower ability for the citrate uptake into vacuole compared with 'AL'. Combined with the metabolites-analyzing results, a model was then established and suggested that the reduction in proton pump activity is the key factor for the low citrate accumulation and the comprehensive metabolite alterations as well in 'HAL'. PMID:27385485

  5. Citrate Accumulation-Related Gene Expression and/or Enzyme Activity Analysis Combined With Metabolomics Provide a Novel Insight for an Orange Mutant

    Guo, Ling-Xia; Shi, Cai-Yun; Liu, Xiao; Ning, Dong-Yuan; Jing, Long-Fei; Yang, Huan; Liu, Yong-Zhong

    2016-01-01

    ‘Hong Anliu’ (HAL, Citrus sinensis cv. Hong Anliu) is a bud mutant of ‘Anliu’ (AL), characterized by a comprehensive metabolite alteration, such as lower accumulation of citrate, high accumulation of lycopene and soluble sugars in fruit juice sacs. Due to carboxylic acid metabolism connects other metabolite biosynthesis and/or catabolism networks, we therefore focused analyzing citrate accumulation-related gene expression profiles and/or enzyme activities, along with metabolic fingerprinting between ‘HAL’ and ‘AL’. Compared with ‘AL’, the transcript levels of citrate biosynthesis- and utilization-related genes and/or the activities of their respective enzymes such as citrate synthase, cytosol aconitase and ATP-citrate lyase were significantly higher in ‘HAL’. Nevertheless, the mitochondrial aconitase activity, the gene transcript levels of proton pumps, including vacuolar H+-ATPase, vacuolar H+-PPase, and the juice sac-predominant p-type proton pump gene (CsPH8) were significantly lower in ‘HAL’. These results implied that ‘HAL’ has higher abilities for citrate biosynthesis and utilization, but lower ability for the citrate uptake into vacuole compared with ‘AL’. Combined with the metabolites-analyzing results, a model was then established and suggested that the reduction in proton pump activity is the key factor for the low citrate accumulation and the comprehensive metabolite alterations as well in ‘HAL’. PMID:27385485

  6. Induction of phytic acid synthesis by abscisic acid in suspension-cultured cells of rice

    Matsuno, Koya; Fujimura, Tatsuhito

    2014-01-01

    A pathway of phytic acid (PA) synthesis in plants has been revealed via investigations of low phytic acid mutants. However, the regulation of this pathway is not well understood because it is difficult to control the environments of cells in the seeds, where PA is mainly synthesized. We modified a rice suspension culture system in order to study the regulation of PA synthesis. Rice cells cultured with abscisic acid (ABA) accumulate PA at higher levels than cells cultured without ABA, and PA a...

  7. Involvement of sigmaS accumulation in repression of the flhDC operon in acidic phospholipid-deficient mutants of Escherichia coli.

    Uchiyama, Junji; Nobue, Yuka; Zhao, Hong; Matsuzaki, Hiroshi; Nagahama, Hideki; Matsuoka, Satoshi; Matsumoto, Kouji; Hara, Hiroshi

    2010-06-01

    Escherichia coli pgsA mutations, which cause acidic phospholipid deficiency, repress transcription of the flagellar master operon flhDC, and thus impair flagellar formation and motility. The molecular mechanism of the strong repression of flhDC transcription in the mutant cells, however, has not yet been clarified. In order to shed light on this mechanism we isolated genes which, when supplied in multicopy, suppress the repression of flhD, and found that three genes, gadW, metE and yeaB, were capable of suppression. Taking into account a previous report that gadW represses sigma(S) production, the level of sigma(S) in the pgsA3 mutant was examined. We found that pgsA3 cells had a high level of sigma(S) and that introduction of a gadW plasmid into pgsA3 cells did reduce the sigma(S) level. The pgsA3 cells exhibited a sharp increase in sigma(S) levels that can only be partially attributed to the slight increase in rpoS transcription; the largest part of the effect is due to a post-transcriptional accumulation of sigma(S). GadW in multicopy exerts its effect by post-transcriptionally downregulating sigma(S). YeaB and MetE in multicopy also exert their effect via sigma(S). Disruption of rpoS caused an increase of the flhD mRNA level, and induction from P(trc)-rpoS repressed the flhD mRNA level. The strong repression of flhD transcription in pgsA3 mutant cells is thus suggested to be caused by the accumulated sigma(S). PMID:20185506

  8. Characterization of 68Zn uptake, translocation, and accumulation into developing grains and young leaves of high Zn-density rice genotype

    Chun-yong WU; Ying FENG; Md. Jahidul Islam SHOHAG; Ling-li LU; Yan-yan WEI; Chong GAO; Xiao-e YANG

    2011-01-01

    Zinc (Zn) is an essential micronutrient for humans, but Zn deficiency has become serious as equally as iron (Fe) and vitamin A deficiencies nowadays. Selection and breeding of high Zn-density crops is a suitable,cost-effective, and sustainable way to improve human health. However, the mechanism of high Zn density in rice grain is not fully understood, especially how Zn transports from soil to grains. Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique. At seedling stage, IR68144 showed higher 68Zn uptake and transport rate to the shoot for the short-term, but no significant difference was observed in both genotypes for the long-term. Zn in xylem sap of IR68144 was consistently higher,and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient (2.0 μmol/L) or surplus (8.0 μmol/L) Zn supply level. IR64 and IR68144 showed similar patterns of 68Zn accumulation in new leaves at seedling stage and in developing grains at ripening stage, whereas 68Zn in new leaves and grains of IR68144 was consistently higher. These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.

  9. Study on accumulation mechanism of cadmium in rice (oriza sativa L.) by micro-XRF imaging and x-ray absorption fine structure analysis utilizing synchrotron radiation

    This paper reports on the distribution of Cd and essential elements in the stems of rice plants, 'Nipponbare' and 'Milyang 23', measured by synchrotron radiation micro-XRF imaging. X-ray absorption near edge structure (XANES) analysis was applied to estimate the chemical forms of Cd in the roots, stems and leaves, aiming to reveal the mechanisms of Cd transport in rice. The results show that the Cd concentration of 'Nipponbare' was found to be higher than that of 'Milyang 23' at the root, although there was no significant difference between these two cultivars at the shoot. In addition, the distribution of Cd and the essential elements inside the plant were clearly revealed by micro-XRF imaging. It was found that Cd was also localized to the bundle. The Cd K-edge XANES analysis indicated that Cd was bound to sulfur in the root for both rice plants. Furthermore, the content of Cd combining with S (Cd-S) in the stem of 'Nipponbare' became 1.5 times higher after exposing to Cd for a long time, while only a slight change in the stem of 'Milyang 23' was found. In contrast with the stem, the leaf of 'Nipponbare' contained a lower Cd-S content than that of the control after a long-term exposure, while that of 'Milyang 23' became higher. In conclusion, the difference in the chemical form of Cd at the shoots affected the different accumulation behaviors of Cd between 'Nipponbare' and 'Milyang 23'. (author)

  10. Transcriptome Analysis of Differentially Expressed Genes Involved in Proanthocyanidin Accumulation in the Rhizomes of Fagopyrum dibotrys and an Irradiation-Induced Mutant.

    Chen, Caixia; Li, Ailian

    2016-01-01

    The rhizome of Fagopyrum dibotrys is a traditional Chinese medicine that has recently gained attention due to substantial findings regarding its bioactive proanthocyanidin (PA) compounds. However, the molecular mechanism underlying PA accumulation in F. dibotrys remains elusive. We previously obtained an irradiation-induced mutant (RM_R) of F. dibotrys that had a higher PA content compared to that of the wild-type (CK_R). The present study aimed to elucidate the molecular mechanism underlying PA accumulation in F. dibotrys by comparing the rhizome transcriptomes of the irradiation-induced mutant and wild-type using RNA-seq analysis. A total of 53,540 unigenes were obtained, of which 29,901 (55.84%) were annotated based on BLAST searches against public databases, and 501 unique sequences were differentially expressed between the two samples, which consisted of 204 up-regulated and 297 down-regulated unigenes. Further analysis showed that the expression patterns of some unigenes encoding enzymes involved in PAs biosynthesis in F. dibotrys rhizomes differed between RM_R and CK_R. In addition, we identified transcription factor families and several cytochrome P450s that may be involved in PA regulation in F. dibotrys. Finally, 12 unigenes that encode PA biosynthetic enzymes were confirmed by qRT-PCR analysis. This study sheds light on the molecular mechanism underlying radiation-mediated flavonoid accumulation and regulation in F. dibotrys rhizomes. These results will also provide a platform for further functional genomic research on this particular species. PMID:27047386

  11. Transcriptome analysis of differentially expressed genes involved in proanthocyanidin accumulation in the rhizomes of Fagopyrum dibotrys and an irradiation-induced mutant

    Caixia eChen

    2016-03-01

    Full Text Available The rhizome of Fagopyrum dibotrys is a traditional Chinese medicine that has recently gained attention due to substantial findings regarding its bioactive proanthocyanidin (PA compounds. However, the molecular mechanism underlying PA accumulation in F.dibotrys remains elusive. We previously obtained an irradiation-induced mutant (RM_R of F.dibotrys that had a higher PA content compared to that of the wild-type (CK_R. The present study aimed to elucidate the molecular mechanism underlying PA accumulation in F. dibotrys by comparing the rhizome transcriptomes of the irradiation-induced mutant and wild-type using RNA-seq analysis. A total of 53,540 unigenes were obtained, of which 29,901 (55.84% were annotated based on BLAST searches against public databases, and 501 unique sequences were differentially expressed between the two samples, which consisted of 204 upregulated and 297 down regulated unigenes. Further analysis showed that the expression patterns of some unigenes encoding enzymes involved in PAs biosynthesis in F.dibotrys rhizomes differed between RM_R and CK_R. In addition, we identified transcription factor families and several cytochrome P450s that may be involved in PA regulation in F. dibotrys. Finally, 12 unigenes that encode PA biosynthetic enzymes were confirmed by qRT-PCR analysis. This study sheds light on the molecular mechanism underlying radiation-mediated flavonoid accumulation and regulation in F. dibotrys rhizomes. These results will also provide a platform for further functional genomic research on this particular species.

  12. Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice-wheat rotational cultivation

    Kikuchi, Tetsuro, E-mail: tetsu-k@hino.meisei-u.ac.jp [Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Okazaki, Masanori, E-mail: masaok24@cc.tuat.ac.jp [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Motobayashi, Takashi, E-mail: takarice@cc.tuat.ac.jp [Field Science Center for Education and Research, Tokyo University of Agriculture and Technology, 3-7-1 Hommachi, Fuchu, Tokyo 183-0027 (Japan)

    2009-08-30

    The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha{sup -1}) and a material derived from MgO and magnesium silicate minerals named 'MgO-SH-A' (2250 and 4500 kg ha{sup -1}1), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice-wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg{sup -1}). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha{sup -1} produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg{sup -1}. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.

  13. Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice-wheat rotational cultivation

    The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha-1) and a material derived from MgO and magnesium silicate minerals named 'MgO-SH-A' (2250 and 4500 kg ha-11), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice-wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg-1). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha-1 produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg-1. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.

  14. Marker-free transgenic (MFT) near-isogenic introgression lines (NIILs) of 'golden' indica rice (cv. IR64) with accumulation of provitamin A in the endosperm tissue.

    Baisakh, Niranjan; Rehana, Sayda; Rai, Mayank; Oliva, Norman; Tan, Jing; Mackill, David J; Khush, Gurdev S; Datta, Karabi; Datta, Swapan K

    2006-07-01

    We have developed near-isogenic introgression lines (NIILs) of an elite indica rice cultivar (IR64) with the genes for beta-carotene biosynthesis from dihaploid (DH) derivatives of golden japonica rice (cv. T309). A careful analysis of the DH lines indicated the integration of the genes of interest [phytoene synthase (psy) and phytoene desaturase (crtI)] and the selectable marker gene (hygromycin phosphotransferase, hph) in two unlinked loci. During subsequent crossing, progenies could be obtained carrying only the locus with psy and crtI, which was segregated independently from the locus containing the hph gene during meiotic segregation. The NIILs (BC(2)F(2)) showed maximum similarity with the recurrent parent cultivar IR64. Further, progenies of two NIILs were devoid of any fragments beyond the left or right border, including the chloramphenicol acetyltransferase (cat) antibiotic resistance gene of the transformation vector. Spectrophotometric readings showed the accumulation of up to 1.06 microg total carotenoids, including beta-carotene, in 1 g of the endosperm. The accumulation of beta-carotene was also evident from the clearly visible yellow colour of the polished seeds. PMID:17177811

  15. Induced mutation for disease resistance in rice with special reference to blast, bacterial blight and tungro

    Rice varieties Ratna, Pusa 2-21, Vijaya and Pankaj have been treated with gamma rays, EMS or sodium azide to improve their resistance against blast, bacterial leaf blight or tungro virus. For blast and tungro, mutants with improved resistance were selected. Variation in reaction to bacterial leaf blight has been used in crossbreeding to accumulate genes for resistance. (author)

  16. [The accumulation of proteins with chitinase activity in the culture media of the parent and mutant Serratia marcescens strain grown in the presence of mitomycin C].

    Iusupova, D V; Petukhova, E V; Sokolova, R B; Gabdrakhmanova, L A

    2002-01-01

    The study of the accumulation pattern of extracellular proteins with chitinase activity in the parent Serratia marcescens strain Bú 211 (ATCC 9986) grown in the presence of mitomycin C and its mutant strain with the constitutive synthesis of chitinases grown in the absence of the inducer showed that chitinase activity appeared in the culture liquids of both strains at the end of the exponential phase (4 h of growth) and reached a maximum in the stationary phase (18-20 h of growth). The analysis of the culture liquids (12 h of growth) by denaturing electrophoresis in PAAG followed by the protein renaturation step revealed the presence of four extracellular proteins with chitinase activity and molecular masses of 21, 38, 52, and 58 kDa. PMID:12449629

  17. Microarray Analysis of Rice d1 (RGA1) Mutant Reveals the Potential Role of G-Protein Alpha Subunit in Regulating Multiple Abiotic Stresses Such as Drought, Salinity, Heat, and Cold.

    Jangam, Annie P; Pathak, Ravi R; Raghuram, Nandula

    2016-01-01

    The genome-wide role of heterotrimeric G-proteins in abiotic stress response in rice has not been examined from a functional genomics perspective, despite the availability of mutants and evidences involving individual genes/processes/stresses. Our rice whole transcriptome microarray analysis (GSE 20925 at NCBI GEO) using the G-alpha subunit (RGA1) null mutant (Daikoku 1 or d1) and its corresponding wild type (Oryza sativa Japonica Nipponbare) identified 2270 unique differentially expressed genes (DEGs). Out of them, we mined for all the potentially abiotic stress-responsive genes using Gene Ontology terms, STIFDB2.0 and Rice DB. The first two approaches produced smaller subsets of the 1886 genes found at Rice DB. The GO approach revealed similar regulation of several families of stress-responsive genes in RGA1 mutant. The Genevestigator analysis of the stress-responsive subset of the RGA1-regulated genes from STIFDB revealed cold and drought-responsive clusters. Meta data analysis at Rice DB revealed large stress-response categories such as cold (878 up/810 down), drought (882 up/837 down), heat (913 up/777 down), and salt stress (889 up/841 down). One thousand four hundred ninety-eight of them are common to all the four abiotic stresses, followed by fewer genes common to smaller groups of stresses. The RGA1-regulated genes that uniquely respond to individual stresses include 111 in heat stress, eight each in cold only and drought only stresses, and two genes in salt stress only. The common DEGs (1498) belong to pathways such as the synthesis of polyamine, glycine-betaine, proline, and trehalose. Some of the common DEGs belong to abiotic stress signaling pathways such as calcium-dependent pathway, ABA independent and dependent pathway, and MAP kinase pathway in the RGA1 mutant. Gene ontology of the common stress responsive DEGs revealed 62 unique molecular functions such as transporters, enzyme regulators, transferases, hydrolases, carbon and protein metabolism

  18. Microarray Analysis of Rice d1 (RGA1) Mutant Reveals the Potential Role of G-Protein Alpha Subunit in Regulating Multiple Abiotic Stresses Such as Drought, Salinity, Heat, and Cold

    Jangam, Annie P.; Pathak, Ravi R.; Raghuram, Nandula

    2016-01-01

    The genome-wide role of heterotrimeric G-proteins in abiotic stress response in rice has not been examined from a functional genomics perspective, despite the availability of mutants and evidences involving individual genes/processes/stresses. Our rice whole transcriptome microarray analysis (GSE 20925 at NCBI GEO) using the G-alpha subunit (RGA1) null mutant (Daikoku 1 or d1) and its corresponding wild type (Oryza sativa Japonica Nipponbare) identified 2270 unique differentially expressed genes (DEGs). Out of them, we mined for all the potentially abiotic stress-responsive genes using Gene Ontology terms, STIFDB2.0 and Rice DB. The first two approaches produced smaller subsets of the 1886 genes found at Rice DB. The GO approach revealed similar regulation of several families of stress-responsive genes in RGA1 mutant. The Genevestigator analysis of the stress-responsive subset of the RGA1-regulated genes from STIFDB revealed cold and drought-responsive clusters. Meta data analysis at Rice DB revealed large stress-response categories such as cold (878 up/810 down), drought (882 up/837 down), heat (913 up/777 down), and salt stress (889 up/841 down). One thousand four hundred ninety-eight of them are common to all the four abiotic stresses, followed by fewer genes common to smaller groups of stresses. The RGA1-regulated genes that uniquely respond to individual stresses include 111 in heat stress, eight each in cold only and drought only stresses, and two genes in salt stress only. The common DEGs (1498) belong to pathways such as the synthesis of polyamine, glycine-betaine, proline, and trehalose. Some of the common DEGs belong to abiotic stress signaling pathways such as calcium-dependent pathway, ABA independent and dependent pathway, and MAP kinase pathway in the RGA1 mutant. Gene ontology of the common stress responsive DEGs revealed 62 unique molecular functions such as transporters, enzyme regulators, transferases, hydrolases, carbon and protein metabolism

  19. Carbon, nitrogen and phosphorus accumulation and partitioning, and C:N:P stoichiometry in late-season rice under different water and nitrogen managements.

    Yushi Ye

    Full Text Available Water and nitrogen availability plays an important role in the biogeochemical cycles of essential elements, such as carbon (C, nitrogen (N and phosphorus (P, in agricultural ecosystems. In this study, we investigated the seasonal changes of C, N and P concentrations, accumulation, partitioning, and C:N:P stoichiometric ratios in different plant tissues (root, stem-leaf, and panicle of late-season rice under two irrigation regimes (continuous flooding, CF; alternate wetting and drying, AWD and four N managements (control, N0; conventional urea at 240 kg N ha(-1, UREA; controlled-release bulk blending fertilizer at 240 kg N ha(-1, BBF; polymer-coated urea at 240 kg N ha(-1, PCU. We found that water and N treatments had remarkable effects on the measured parameters in different plant tissues after transplanting, but the water and N interactions had insignificant effects. Tissue C:N, N:P and C:P ratios ranged from 14.6 to 52.1, 3.1 to 7.8, and 76.9 to 254.3 over the rice growing seasons, respectively. The root and stem-leaf C:N:P and panicle C:N ratios showed overall uptrends with a peak at harvest whereas the panicle N:P and C:P ratios decreased from filling to harvest. The AWD treatment did not affect the concentrations and accumulation of tissue C and N, but greatly decreased those of P, resulting in enhanced N:P and C:P ratios. N fertilization significantly increased tissue N concentration, slightly enhanced tissue P concentration, but did not affect tissue C concentration, leading to a significant increase in tissue N:P ratio but a decrease in C:N and C:P ratios. Our results suggested that the growth of rice in the Taihu Lake region was co-limited by N and P. These findings broadened our understanding of the responses of plant C:N:P stoichiometry to simultaneous water and N managements in subtropical high-yielding rice systems.

  20. Carbon, nitrogen and phosphorus accumulation and partitioning, and C:N:P stoichiometry in late-season rice under different water and nitrogen managements.

    Ye, Yushi; Liang, Xinqiang; Chen, Yingxu; Li, Liang; Ji, Yuanjing; Zhu, Chunyan

    2014-01-01

    Water and nitrogen availability plays an important role in the biogeochemical cycles of essential elements, such as carbon (C), nitrogen (N) and phosphorus (P), in agricultural ecosystems. In this study, we investigated the seasonal changes of C, N and P concentrations, accumulation, partitioning, and C:N:P stoichiometric ratios in different plant tissues (root, stem-leaf, and panicle) of late-season rice under two irrigation regimes (continuous flooding, CF; alternate wetting and drying, AWD) and four N managements (control, N0; conventional urea at 240 kg N ha(-1), UREA; controlled-release bulk blending fertilizer at 240 kg N ha(-1), BBF; polymer-coated urea at 240 kg N ha(-1), PCU). We found that water and N treatments had remarkable effects on the measured parameters in different plant tissues after transplanting, but the water and N interactions had insignificant effects. Tissue C:N, N:P and C:P ratios ranged from 14.6 to 52.1, 3.1 to 7.8, and 76.9 to 254.3 over the rice growing seasons, respectively. The root and stem-leaf C:N:P and panicle C:N ratios showed overall uptrends with a peak at harvest whereas the panicle N:P and C:P ratios decreased from filling to harvest. The AWD treatment did not affect the concentrations and accumulation of tissue C and N, but greatly decreased those of P, resulting in enhanced N:P and C:P ratios. N fertilization significantly increased tissue N concentration, slightly enhanced tissue P concentration, but did not affect tissue C concentration, leading to a significant increase in tissue N:P ratio but a decrease in C:N and C:P ratios. Our results suggested that the growth of rice in the Taihu Lake region was co-limited by N and P. These findings broadened our understanding of the responses of plant C:N:P stoichiometry to simultaneous water and N managements in subtropical high-yielding rice systems. PMID:24992006

  1. Enhanced Photosynthesis and Growth in atquac1 Knockout Mutants Are Due to Altered Organic Acid Accumulation and an Increase in Both Stomatal and Mesophyll Conductance.

    Medeiros, David B; Martins, Samuel C V; Cavalcanti, João Henrique F; Daloso, Danilo M; Martinoia, Enrico; Nunes-Nesi, Adriano; DaMatta, Fábio M; Fernie, Alisdair R; Araújo, Wagner L

    2016-01-01

    Stomata control the exchange of CO2 and water vapor in land plants. Thus, whereas a constant supply of CO2 is required to maintain adequate rates of photosynthesis, the accompanying water losses must be tightly regulated to prevent dehydration and undesired metabolic changes. Accordingly, the uptake or release of ions and metabolites from guard cells is necessary to achieve normal stomatal function. The AtQUAC1, an R-type anion channel responsible for the release of malate from guard cells, is essential for efficient stomatal closure. Here, we demonstrate that mutant plants lacking AtQUAC1 accumulated higher levels of malate and fumarate. These mutant plants not only display slower stomatal closure in response to increased CO2 concentration and dark but are also characterized by improved mesophyll conductance. These responses were accompanied by increases in both photosynthesis and respiration rates, without affecting the activity of photosynthetic and respiratory enzymes and the expression of other transporter genes in guard cells, which ultimately led to improved growth. Collectively, our results highlight that the transport of organic acids plays a key role in plant cell metabolism and demonstrate that AtQUAC1 reduce diffusive limitations to photosynthesis, which, at least partially, explain the observed increments in growth under well-watered conditions. PMID:26542441

  2. The rice semi-dwarf mutant sd37, caused by a mutation in CYP96B4, plays an important role in the fine-tuning of plant growth.

    Jie Zhang

    Full Text Available Plant cytochrome P450 has diverse roles in developmental processes and in the response to environmental cues. Here, we characterized the rice (Oryza sativa L ssp. indica cultivar 3037 semi-dwarf mutant sd37, in which the gene CYP96B4 (Cytochrome P450 96B subfamily was identified and confirmed as the target by map-based cloning and a complementation test. A point mutation in the SRS2 domain of CYP96B4 resulted in a threonine to lysine substitution in the sd37 mutant. Examination of the subcellular localization of the protein revealed that SD37 was ER-localized protein. And SD37 was predominantly expressed in the shoot apical meristem and developing leaf and root maturation zone but not in the root apical meristem. The sd37 leaves, panicles, and seeds were smaller than those of the wild type. Histological analysis further revealed that a decrease in cell number in the mutant, specifically in the shoots, was the main cause of the dwarf phenotype. Microarray analysis demonstrated that the expression of several cell division-related genes was disturbed in the sd37 mutant. In addition, mutation or strongly overexpression of SD37 results in dwarf plants but moderate overexpression increases plant height. These data suggest that CYP96B4 may be an important regulator of plant growth that affects plant height in rice.

  3. Accumulation of Phosphorus-Containing Compounds in Developing Seeds of Low-Phytate Pea (Pisum sativum L. Mutants

    Arun S.K. Shunmugam

    2014-12-01

    Full Text Available Low phytic acid (lpa crops are low in phytic acid and high in inorganic phosphorus (Pi. In this study, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were grown in field trials for two years. The lpa genotypes were lower in IP6 and higher in Pi when compared to CDC Bronco. The total P concentration was similar in lpa genotypes and CDC Bronco throughout the seed development. The action of myo-inositol phosphate synthase (MIPS (EC 5.5.1.4 is the first and rate-limiting step in the phytic acid biosynthesis pathway. Aiming at understanding the genetic basis of the lpa mutation in the pea, a 1530 bp open reading frame of MIPS was amplified from CDC Bronco and the lpa genotypes. Sequencing results showed no difference in coding sequence in MIPS between CDC Bronco and lpa genotypes. Transcription levels of MIPS were relatively lower at 49 days after flowering (DAF than at 14 DAF for CDC Bronco and lpa lines. This study elucidated the rate and accumulation of phosphorus compounds in lpa genotypes. The data also demonstrated that mutation in MIPS was not responsible for the lpa trait in these pea lines.

  4. Effect of High Temperature at Ripening Stage on the Reserve Accumulation in Seed in Some Rice Cultivars

    ZAKARIA, Sabaruddin / MATSUDA, Toshiaki / TAJIMA, Shingo / NITTA, Youji

    2002-01-01

    The resistance to high-temperature stress and the structural appearance of the imperfect grains caused by a high temperature at the ripening stage were studied using 13 selected cultivars of rice. High temperature treatment (daily maximum temperature range, 32-40℃) given from the 4th day after heading caused the decrease in panicle weight in all of the cultivars examined. The number of empty grains in the upper and lower parts of a panicle was increased by the high temperature in 10 cultivars...

  5. Investigation of biogeochemical controls on the formation, uptake and accumulation of methylmercury in rice paddies in the vicinity of a coal-fired power plant and a municipal solid waste incinerator in Taiwan.

    Su, Yen-Bin; Chang, Wei-Chun; Hsi, Hsing-Cheng; Lin, Chu-Ching

    2016-07-01

    Recent studies have shown that rice consumption is another critical route of human exposure to methylmercury (MeHg), the most toxic and accumulative form of mercury (Hg) in the food web. Yet, the mechanisms that underlie the production and accumulation of MeHg in the paddy ecosystem are still poorly understood. In 2013 and 2014, we conducted field campaigns and laboratory experiments over a rice growing season to examine Hg and MeHg cycling, as well as associated biogeochemistry in a suite of paddies close to a municipal solid waste incinerator and a coal-fired power plant station in Taiwan. Concentrations of total Hg and MeHg in paddy soil and rice grain at both sites were low and found not to exceed the control standards for farmland soil and edible rice in Taiwan. However, seasonal variations of MeHg concentrations observed in pore water samples indicate that the in situ bioavailability of inorganic Hg and activity of Hg-methylating microbes in the rhizosphere increased from the early-season and peaked at the mid-season, presumably due to the anoxia created under flooded conditions and root exudation of organic compounds. The presence of Hg-methylators was also confirmed by the hgcA gene detected in all root soil samples. Subsequent methylation tests performed by incubating the root soil with inorganic Hg and an inhibitor or stimulant specific for certain microbes further revealed that sulfate-reducers might have been the principal Hg-methylting guild at the study sites. Interestingly, results of hydroponic experiments conducted by cultivating rice in a defined nutrient solution amended with fixed MeHg and varying levels of MeHg-binding ligands suggested that chemical speciation in soil pore water may play a key role in controlling MeHg accumulation in rice, and both passive and active transport pathways seem to take place in the uptake of MeHg in rice roots. PMID:27070857

  6. Overexpression of Rice Glutaredoxin OsGrx_C7 and OsGrx_C2.1 Reduces Intracellular Arsenic Accumulation and Increases Tolerance in Arabidopsis thaliana.

    Verma, Pankaj K; Verma, Shikha; Pande, Veena; Mallick, Shekhar; Deo Tripathi, Rudra; Dhankher, Om P; Chakrabarty, Debasis

    2016-01-01

    Glutaredoxins (Grxs) are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice), the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As) tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops. PMID:27313586

  7. Enhanced cadmium accumulation and tolerance in transgenic tobacco overexpressing rice metal tolerance protein gene OsMTP1 is promising for phytoremediation.

    Das, Natasha; Bhattacharya, Surajit; Maiti, Mrinal K

    2016-08-01

    One of the most grievous heavy metal pollutants in the environment is cadmium (Cd), which is not only responsible for the crop yield loss owing to its phytotoxicity, but also for the human health hazards as the toxic elements usually accumulate in the consumable parts of crop plants. In the present study, we aimed to isolate and functionally characterize the OsMTP1 gene from indica rice (Oryza sativa L. cv. IR64) to study its potential application for efficient phytoremediation of Cd. The 1257 bp coding DNA sequence (CDS) of OsMTP1 encodes a ∼46 kDa protein belonging to the cation diffusion facilitator (CDF) or metal tolerance/transport protein (MTP) family. The OsMTP1 transcript in rice plant was found to respond during external Cd stress. Heterologous expression of OsMTP1 in tobacco resulted in the reduction of Cd stress-induced phytotoxic effects, including growth inhibition, lipid peroxidation, and cell death. Compared to untransformed control, the transgenic tobacco plants showed enhanced vacuolar thiol content, indicating vacuolar localization of the sequestered Cd. The transgenic tobacco plants exhibited significantly higher biomass growth (2.2-2.8-folds) and hyperaccumulation of Cd (1.96-2.22-folds) compared to untransformed control under Cd exposure. The transgenic plants also showed moderate tolerance and accumulation of arsenic (As) upon exogenous As stress, signifying broad substrate specificity of OsMTP1. Together, findings of our research suggest that the transgenic tobacco plants overexpressing OsMTP1 with its hyperaccumulating activity and increased growth rate could be useful for future phytoremediation applications to clean up the Cd-contaminated soil. PMID:27214086

  8. Overexpression of rice glutaredoxin OsGrx_C7 and OsGrx_C2.1 reduces intracellular arsenic accumulation and increases tolerance in Arabidopsis thaliana

    Pankaj Kumar Verma

    2016-06-01

    Full Text Available Glutaredoxins (Grxs are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice, the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops.

  9. Short-term UV-B radiation and ozone exposure effects on aromatic secondary metabolite accumulation and shoot growth of flavonoid-deficient Arabidopsis mutants

    The presence of UV-absorptive substances in the epidermal cells of leaves is thought to protect mesophyll tissues from the harmful effects of UV-B radiation. We examined the influence of short-term UV-B exposures on UV-absorptive (330 nm) sinapates and flavonols, and on shoot growth of the Arabidopsis wild type ecotype Landsberg erecta and two mutants. 114 deficient in chalcone synthase, and 115, deficient in chalcone/flavonone isomerase. Sequential ozone exposures were used to determine the effects of oxidative stress The levels of sinapates and flavonols on a leaf fresh weight basis increased substantially in the wild type and sinapates increased in the 114 mutant in vegetative vegetative/reproductive transitional and reproductive stage plants in response to short-term (48h) UV-B radiation. When UV-B was discontinued the levels generally decreased lo pre-exposure levels after 48 h in vegetative/reproductive but not in reproductive plants. Exposure to ozone before or alter UV-B treatment did not consistently affect the levels of these UV-absorptive compounds. Dry matter accumulation was less affected by UV-B at the vegetative and reproductive stages than at the vegetative/reproductive stage. At the vegetative/reproductive stage, shoot growth of all 3 genotypes was retarded by UV-B. Growth was not retarded by short-term ozone exposure alone but when exposure to ozone followed UV-B exposure, growth was reduced in all genotypes. Leaf cupping appeared on 115 plants exposed to UV-B

  10. Cardiolipin Molecular Species with Shorter Acyl Chains Accumulate in Saccharomyces cerevisiae Mutants Lacking the Acyl Coenzyme A-binding Protein Acb1p

    Rijken, Pieter J.; Houtkooper, Riekelt H.; Akbari, Hana; Brouwers, Jos F.; Koorengevel, Martijn C.; de Kruijff, Ben; Frentzen, Margrit; Vaz, Frédéric M.; de Kroon, Anton I. P. M.

    2009-01-01

    The function of the mitochondrial phospholipid cardiolipin (CL) is thought to depend on its acyl chain composition. The present study aims at a better understanding of the way the CL species profile is established in Saccharomyces cerevisiae by using depletion of the acyl-CoA-binding protein Acb1p as a tool to modulate the cellular acyl chain content. Despite the presence of an intact CL remodeling system, acyl chains shorter than 16 carbon atoms (C16) were found to accumulate in CL in cells lacking Acb1p. Further experiments revealed that Taz1p, a key CL remodeling enzyme, was not responsible for the shortening of CL in the absence of Acb1p. This left de novo CL synthesis as the only possible source of acyl chains shorter than C16 in CL. Experiments in which the substrate specificity of the yeast cardiolipin synthase Crd1p and the acyl chain composition of individual short CL species were investigated, indicated that both CL precursors (i.e. phosphatidylglycerol and CDP-diacylglycerol) contribute to comparable extents to the shorter acyl chains in CL in acb1 mutants. Based on the findings, we conclude that the fatty acid composition of mature CL in yeast is governed by the substrate specificity of the CL-specific lipase Cld1p and the fatty acid composition of the Taz1p substrates. PMID:19656950

  11. OsMADS6 plays an essential role in endosperm nutrient accumulation and is subject to epigenetic regulation in rice (Oryza sativa).

    Zhang, Jian; Nallamilli, Babi R; Mujahid, Hana; Peng, Zhaohua

    2010-11-01

    MADS-box transcription factors are known for their roles in plant growth and development. The regulatory mechanisms of spatial and temporal specific expression of MADS-box genes and the function of MADS-box genes in other biological processes are still to be explored. Here, we report that OsMADS6 is highly expressed in flower and endosperm in Oryza sativa (rice). In addition to displaying a homeotic organ identity phenotype in all the four whorls of the flowers, the endosperm development is severely affected in its mutant. At least 32% of the seeds lacked starch filling and aborted. For seeds that have starch filling and develop to maturity, the starch content is reduced by at least 13%. In addition, the seed shape changes from elliptical to roundish, and the protein content increases from 12.1 to 15.0% (P < 0.05). Further investigation shows that ADP-glucose pyrophosphorylase genes, encoding the rate-limiting step enzyme in the starch synthesis pathway, are subject to the regulation of OsMADS6. Chromatin immunoprecipitation (ChIP)-PCR analyses on the chromatin of the OsMADS6 gene find that H3K27 is trimethylated in tissues where OsMADS6 is silenced, and that H3K36 is trimethylated in tissues where OsMADS6 is highly activated. Point mutation analysis reveals that leucine at position 83 is critical to OsMADS6 function. PMID:20822505

  12. Photomorphogenic responses to UV radiation III: a comparative study of UVB effects on anthocyanin and flavonoid accumulation in wild-type and aurea mutant of tomato (Lycopersicon esculentum Mill.)

    Brandt, K. [Danish Inst. of Plant and Soil Science, Arslev (Denmark); Giannini, A. [Scuola Superiore Studi Univ. Perfezionamento Sant Anna, Pisa (Italy); Lercari, B. [Pisa Univ. (Italy). Dip. Biologia Piante Agrarie

    1995-12-01

    The UV-mediated induction of anthocyanin and UV-absorbing compounds was characterized in etiolated hypocotyls of wild-type and aurea (au) mutant tomato seedlings. Ultraviolet radiation induced significant increases of anthocyanin and UV-absorbing compounds in hypocotyls of the au mutant and of its isogenic wild-type, but the differences in the time courses of UV-induced pigment accumulation indicate that different photoregulatory mechanisms are involved for each of these two groups of pigments. It appears that prolonged presence of adequate levels of UVB (290-320 nm) energy and consequently the action of a specific UVB photoreceptor are indispensable for the photoinduction of anthocyanin accumulation in UV-irradiated hypocotyl of the au mutant that is missing the labile phytochrome pool. The large difference found between the wild-type and the au mutant strongly indicate the involvement of labile phytochrome as the primary functional photoreceptor for the photoinduction of anthocyanin accumulation in wild-type tomato hypocotyls. (author).

  13. Photomorphogenic responses to UV radiation III: a comparative study of UVB effects on anthocyanin and flavonoid accumulation in wild-type and aurea mutant of tomato (Lycopersicon esculentum Mill.)

    The UV-mediated induction of anthocyanin and UV-absorbing compounds was characterized in etiolated hypocotyls of wild-type and aurea (au) mutant tomato seedlings. Ultraviolet radiation induced significant increases of anthocyanin and UV-absorbing compounds in hypocotyls of the au mutant and of its isogenic wild-type, but the differences in the time courses of UV-induced pigment accumulation indicate that different photoregulatory mechanisms are involved for each of these two groups of pigments. It appears that prolonged presence of adequate levels of UVB (290-320 nm) energy and consequently the action of a specific UVB photoreceptor are indispensable for the photoinduction of anthocyanin accumulation in UV-irradiated hypocotyl of the au mutant that is missing the labile phytochrome pool. The large difference found between the wild-type and the au mutant strongly indicate the involvement of labile phytochrome as the primary functional photoreceptor for the photoinduction of anthocyanin accumulation in wild-type tomato hypocotyls. (author)

  14. Effects of Weak Light on Starch Accumulation and Starch Synthesis Enzyme Activities in Rice at the Grain Filling Stage

    LI Tian; Ryu OHSUGI; Tohru YAMAGISHI; Haruto SASAKI

    2006-01-01

    Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments after flowering were studied using two dce varieties IR72 (indica) and Nipponbare (japonica) as materials. Under shading treatments, the starch,amylose and sucrose contents decreased, while ADP-glucose pyrophosphorylase (ADPGPPase) activity only changed a little, soluble starch synthase activity and granule bound starch synthase activity decreased, soluble starch branching enzyme (SSBE, Q-enzyme) activity and granule bound starch branching enzyme (GBSBE, Q-enzyme) activity increased, and starch debranching enzyme (DBE, R-enzyme) activity vaded with varieties. Correlation analyses showed that the changes of starch content were positively and significantly correlated with the changes of sucrose content in the weak light. Both ADPGPPase activity and SSBE activity were positively and significantly correlated with starch accumulation rate. It was implied that the decline of starch synthase activities was related to the decrease of starch content and the increase of the activity of starch branching enzyme played an important role in the decrease of the ratio of amylose to the total starch under the weak light.

  15. Gene profiling of postnatal Mfrprd6 mutant eyes reveals differential accumulation of Prss56, visual cycle and phototransduction mRNAs.

    Ramani Soundararajan

    Full Text Available Mutations in the membrane frizzled-related protein (MFRP/Mfrp gene, specifically expressed in the retinal pigment epithelium (RPE and ciliary body, cause nanophthalmia or posterior microphthalmia with retinitis pigmentosa in humans, and photoreceptor degeneration in mice. To better understand MFRP function, microarray analysis was performed on eyes of homozygous Mfrprd6 and C57BL/6J mice at postnatal days (P 0 and P14, prior to photoreceptor loss. Data analysis revealed no changes at P0 but significant differences in RPE and retina-specific transcripts at P14, suggesting a postnatal influence of the Mfrprd6 allele. A subset of these transcripts was validated by quantitative real-time PCR (qRT-PCR. In Mfrprd6 eyes, a significant 1.5- to 2.0-fold decrease was observed among transcripts of genes linked to retinal degeneration, including those involved in visual cycle (Rpe65, Lrat, Rgr, phototransduction (Pde6a, Guca1b, Rgs9, and photoreceptor disc morphogenesis (Rpgrip1 and Fscn2. Levels of RPE65 were significantly decreased by 2.0-fold. Transcripts of Prss56, a gene associated with angle-closure glaucoma, posterior microphthalmia and myopia, were increased in Mfrprd6 eyes by 17-fold. Validation by qRT-PCR indicated a 3.5-, 14- and 70-fold accumulation of Prss56 transcripts relative to controls at P7, P14 and P21, respectively. This trend was not observed in other RPE or photoreceptor mutant mouse models with similar disease progression, suggesting that Prss56 upregulation is a specific attribute of the disruption of Mfrp. Prss56 and Glul in situ hybridization directly identified Müller glia in the inner nuclear layer as the cell type expressing Prss56. In summary, the Mfrprd6 allele causes significant postnatal changes in transcript and protein levels in the retina and RPE. The link between Mfrp deficiency and Prss56 up-regulation, together with the genetic association of human MFRP or PRSS56 variants and ocular size, raises the possibility that

  16. Accumulation of 137Cs by rice grown in four types of soil contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident in 2011 and 2012

    The ability to predict radiocesium transfer from soil to agricultural products is necessary for assessing management options in a radiocesium contaminated area. In this study, we evaluated the differences in transfer factors among soil samples and the differences in transfer factors between the first and the second years of contamination in rice. We employed pot experiments using four types of soils that are representative of the agricultural soils present in the Fukushima Prefecture contaminated by 137Cs released from the Fukushima Dai-ichi Nuclear Power Plant after the March 2011 accident. The experiments were conducted during the 2011 and 2012 growing seasons. The geometric mean of transfer factors for brown rice and inedible rice part was 0.011 and 0.031, respectively, in 2011 and 0.0061 and 0.020, respectively, in 2012. The average decreasing rate of the transfer factor was 40% and 30% in brown rice and inedible rice part, respectively, from 2011 to 2012, presumably owing to the irreversible sorption of 137Cs to clay minerals. - Highlights: • Rice was grown in the first and the second year from 137Cs contamination. • Transfer factor was measured for rice grown in four soils contaminated by 137Cs. • Decreasing rate of transfer factor was estimated to be 40% in brown rice

  17. Foliar application of selenium-silicon sol reduced arsenic accumulation in rice%叶面喷施硒硅复合溶胶抑制水稻砷积累效应研究

    徐向华; 刘传平; 唐新莲; 雷静; 顾明华; 李芳柏

    2014-01-01

    Arsenic is a non-threshold carcinogenic metalloid. It becomes a growing public concern on amelioration the As contamination in paddy soils and reduction the As transfer to rice in recent years. In order to reduce the accumulation of arsenic in rice (Oryza sativa L.), a series of concentrations of selenium doped silica sols were prepared by hydrothermal synthesis method. The effects of foliar application of selenium-silica sols on the arsenic accumulation in rice were investigated with pot and field experiments. The results showed that foliar application of selenium doped silicon sol was effective in alleviating the arsenic toxicity to rice, increasing selenium content of rice, and inhibiting the accumulation of arsenic in rice. Comparing with the control in the pot experiments, 1%Se doped silica sol (1%Se-Si) foliar application increased the rice grain dry weight by 43.8%, while decreased the arsenic concentration in rice grain by 46% and increased Se concentration in rice grain from 0.050 mg·kg-1 to 0.272 mg·kg-1. Comparing with 1% sodium selenite foliar application (1%Se) in the pot experiments, the dry weight of rice grain increased by 65.4%, while the As concentration in rice grain decreased by 33.1% with 1% Se doped silica sol (1%Se-Si) treatment. Field experiment results showed that foliar application of selenium-silicon composite sol could significantly inhibit the accumulation of arsenic in rice. With the foliar application of selenium-silica composite sols, the arsenic concentration of rice grain decreased with the increasing doping amount of selenium added into the selenium-silica sols, while the selenium content increased significantly with the increasing doping amount of selenium. The optimal doping of selenium was 0.5%, foliar application of this kind of Se doped silica sol, the total arsenic concentration of rice decreased from 0.25 mg·kg-1 of control to 0.14 mg·kg-1, and the selenium concentration in rice grain was 0.26 mg·kg-1, which was

  18. Effects of space mutation on P(T) GMS-line Pei'ai 64S of rice and SSR analysis of mutants

    Some traits of the progenies SP1, SP2 and SP3 derived from Pei'ai 64S treated by space flight of recoverable satellite were studied, and polymorphism analysis of SSR for the mutants were carried out. The results showed that no difference between the treated Pei'ai 64S and the original one in germination rate, survival seedling rate, plant height, heading data and plant type in SP1 was observed, but there was significant difference in fertility, plant height and grain shape in generation of SP2. Some mutants with much bigger stigma than that of the original Pei'ai 64S were obtained in SP3, and it would be useful in improving the out-crossing rate and enhancing the seed production of Pei'ai 64S. In addition, SSR marker analysis for ten mutants indicated that the average mutant frequency of SSR loci for the mutants was 23.33% and the mutant loci randomly distributed along the chromosomes. Among the mutant SSR loci about 55.21% showed changes in band number and 44.78% in molecular weight. DNA deficiency and duplication might be the main reason of mutation caused by space flight. (authors)

  19. Genetic Analysis and Fine Mapping of a Premature Leaf Senescence Mutant in Rice (Orzya sativa L.)%水稻早衰叶突变体 PLS2的遗传分析与基因定位

    张涛; 郑家奎; 孙玉莹; 郑建敏; 程治军; 蒋开锋; 杨莉; 曹应江; 游书梅; 万建民

    2014-01-01

    叶片早衰引起叶绿素和其他大分子被降解,叶片光合能力降低。这个过程常伴随着活性氧(ROS)的积累,以及细胞中抗氧化酶(SOD、CAT 和 APX)活性的降低,衰老相关基因(SAG)表达量上调,最终导致整个植株过早成熟,产量降低。因此,研究水稻早衰遗传机制和基因功能对于水稻的遗传改良具有重要的作用和意义。PLS2是通过航天育种工程经空间辐射诱变得来的突变体,在孕穗期表现早衰。与野生型相比, PLS2的光合能力降低,株高变矮,节间和穗长缩短,分蘖数和有效分蘖数减少,穗粒数和结实率明显下降,千粒重降低,穗发育不良,灌浆不充分;叶片的CAT 活性显著降低、H2O2积累、死亡细胞增加,叶绿体结构变差,叶绿体中淀粉和嗜锇颗粒增多。黑暗处理加速突变体叶片衰老,叶绿体超微结构球状化。利用 PLS2/蜀恢527和 PLS2/02428的隐性定位群体,将 pls2定位在第3染色体标记 RM14704(8674283 bp)与 SL-I-5(8758394 bp)之间,物理距离84.11 kb,区间内包括14个基因,测序发现在 LOC_Os03g15840第9个外显子第41位的 C 被替换为 T,导致精氨酸(R)替换为半胱氨酸(C), LOC_Os3g15840编码水稻中的一个糖基转移酶(glycosyltransferases, GTs),可能是 pls2的候选基因。为下一步调控基因的克隆和功能研究奠定了基础。%Leaf senescence induces degradation of chlorophyll and other macromolecules, reducing leaf photosynthetic capacity. This process is accompanied by the accumulation of reactive oxygen species (ROS), the decreasing of cell antioxidant enzyme (SOD, CAT, and APX) activity, and the increasing of aging related gene (SAG) expression, leading in early maturity and yield reduction. Therefore, studies on the genetic mechanism and gene function of premature senescence in rice, has the important ef-fect and significance in genetic improvement of rice. PLS2 from space radiation mutation breeding project showed leaf

  20. Rice koji reduced body weight gain, fat accumulation, and blood glucose level in high-fat diet-induced obese mice

    Yumiko Yoshizaki

    2014-08-01

    Full Text Available Rice koji is considered a readily accessible functional food that may have health-promoting effects. We investigated whether white, yellow, and red koji have the anti-obesity effect in C57BL/6J mice fed a high-fat diet (HFD, which is a model for obesity. Mice were fed HFD containing 10% (w/w of rice koji powder or steamed rice for 4 weeks. Weight gain, epididymal white adipose tissue, and total adipose tissue weight were significantly lower in all rice koji groups than in the HFD-rice group after 4 weeks. Feed efficiency was significantly reduced in the yellow koji group. Blood glucose levels were significantly lower in the white and red koji groups with HOMA-R and leptin levels being reduced in the white koji group. White and red koji increased glucose uptake and GLUT4 protein expression in L6 myotube cells. These results showed that all rice koji have the anti-obesity or anti-diabetes effects although the mechanisms may differ depending on the type of rice koji consumed.

  1. Improved plant growth and Zn accumulation in grains of rice (Oryza sativa L.) by inoculation of endophytic microbes isolated from a Zn Hyperaccumulator, Sedum alfredii H.

    Wang, Yuyan; Yang, Xiaoe; Zhang, Xincheng; Dong, Lanxue; Zhang, Jie; Wei, Yanyan; Feng, Ying; Lu, Lingli

    2014-02-26

    This study is to investigate the possibility of zinc (Zn) biofortification in the grains of rice (Oryza sativa L.) by inoculation of endophytic strains isolated from a Zn hyperaccumulator, Sedum alfredii Hance. Five endophytic strains, Burkholderia sp. SaZR4, Burkholderia sp. SaMR10, Sphingomonas sp. SaMR12, Variovorax sp. SaNR1, and Enterobacter sp. SaCS20, isolated from S. alfredii, were inoculated in the roots of Japonica rice Nipponbare under hydroponic condition. Fluorescence images showed that endophytic strains successfully colonized rice roots after 72 h. Improved root morphology and plant growth of rice was observed after inoculation with endophytic strains especially SaMR12 and SaCS20. Under hydroponic conditions, endophytic inoculation with SaMR12 and SaCS20 increased Zn concentration by 44.4% and 51.1% in shoots, and by 73.6% and 83.4% in roots, respectively. Under soil conditions, endophytic inoculation with SaMR12 and SaCS20 resulted in an increase of grain yields and elevated Zn concentrations by 20.3% and 21.9% in brown rice and by 13.7% and 11.2% in polished rice, respectively. After inoculation of SaMR12 and SaCS20, rhizosphere soils of rice plants contained higher concentration of DTPA-Zn by 10.4% and 20.6%, respectively. In situ micro-X-ray fluorescence mapping of Zn confirmed the elevated Zn content in the rhizosphere zone of rice treated with SaMR12 as compared with the control. The above results suggested that endophytic microbes isolated from S. alfredii could successfully colonize rice roots, resulting in improved root morphology and plant growth, increased Zn bioavailability in rhizosphere soils, and elevated grain yields and Zn densities in grains. PMID:24447030

  2. 不同有机物料育秧基质对水稻秧苗生长及养分积累的影响%Effect of different organic materials substrate on rice seedling growth and nutrients accumulation

    宋鹏慧; 方玉凤; 王晓燕; 庞荔丹; 戴建军

    2015-01-01

    Effects of different organic materials on rice seedling growth and nutrients accumulation were studied through rice seedling pot experiment. Results showed that: (1) The COC was the optimal substrate, which was mixed in different propor-tions by ground corn stalks, organic manure, peat, zeolite, vermiculite, fine river sand, carbon powder, etc. The quality of rice seedlings cultured on it was the best; (2) Effects of different materials on the growth of rice seedling were that ground corn stalk was better than rice shell powder and mushroom residue effect was poorer; (3) For the rice seeding growth, treat-ment of carbon powder added were better than all the other ones among the treatments of the same ratio. Results of this study would provide a theoretical basis for selecting material of the substrate production of rice seedling.%通过水稻育苗盆栽试验,研究了不同有机物料育秧基质对水稻秧苗生长及养分积累的影响。结果表明:(1) COC (玉米秸秆+碳粉)为最优基质处理,该处理的基质是由粉碎玉米秸秆、有机肥、草炭、沸石、蛭石、细河沙、碳粉等按不同配比混合而成,用这种基质的所育水稻苗生长状况最好;(2)不同有机物料育秧基质对水稻苗生长的影响,玉米秸秆好于水稻壳粉,菇渣的效果较差;(3)相同配比的处理间,加碳处理均优于不加碳处理。本研究结果对水稻育苗基质生产中的材料选择提供了理论依据。

  3. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for

  4. The use of induced mutation combined with crossing in high quality rice breeding

    The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

  5. The use of induced mutation combined with crossing in high quality rice breeding

    Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy [Agricultural Genetics Institute, Division of Genetics and Hybrid Rice Technology, Hanoi (Viet Nam); Nguyen Minh Cong [Hanoi No. 1 Teacher Training Univ., Department of Genetics (Viet Nam)

    2001-03-01

    The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

  6. Blue-light mediated accumulation of nuclear-encoded transcripts coding for proteins of the thylakoid membrane is absent in the phytochrome-deficient aurea mutant of tomato

    Polyclonal antibodies against pea phytochrome detect 2 protein bands (about 116 and 120 kDa) on blots of crude protein extracts and protein of microsomal preparations of dark-grown tomato seedlings. Both protein bands are undetectable in Western blots of the aurea mutant extracts. Neither protein band is detectable after isogenic wild-type seedlings are illuminated with 3 h of red light, either in the crude extract or in the membrane fraction of the irradiated seedlings; this result is consistent with the hypothesis that both bands are phytochrome. When dark-grown wild-type seedlings are illuminated with 3 h of red light or blue light against a red light background, the transcript levels for chlorophyll a/b-binding proteins of photosystem I and II, plastocyanin, and the subunit II of photosystem I increase. In all cases, the same fluence rate of blue light is much more effective than red light alone, a result that indicates the involvement of a blue/UV-A light photoreceptor in addition to the involvement of the far-red-absorbing form of phytochrome, Pfr. The aurea mutant responds neither to red light nor to blue light. Thus, no Pfr-independent induction of the four transcripts by a blue/UV-A light photoreceptor can be measured in the aurea mutant

  7. UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens.

    Zheng, Dawei; Wang, Yi; Han, Yu; Xu, Jin-Rong; Wang, Chenfang

    2016-01-01

    Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism. PMID:27095476

  8. Characterization of a Purine Permease Family Gene OsPUP7 Involved in Growth and Development Control in Rice

    Zhuyun Qi; Lizhong Xiong

    2013-01-01

    In this study, PUP-type cytokinin transporter genes were identified in rice (Oryza sativa L.). The Oryza sativa purine permease (OsPUP) family has 12 members that show similar predicted protein sequences with AtPUPs. To reveal the functions of OsPUP genes, we searched the T-DNA mutant library of rice and found one mutant for the member OsPUP7. The T-DNA insertion caused a new transcript that encodes a protein with 26 amino acids different from the native OsPUP7 at the C-terminus. The mutant showed multiple phenotypic changes including increased plant height, big seeds, and delayed flowering. The mutant also showed increased sensitivity to drought and salt stresses and treatments with kinetin and abscisic acid. OsPUP7 is expressed mainly in the vascular bundle, pistil, and stamens. The measurement of cytokinins (CKs) showed that CK content in the mutant spikelets accumulated higher than that in the wild type. Moreover, uptake experiment in the yeast fcy2 mutant suggested that OsPUP7 has the ability to transport caffeine, a CK derivative. Our results indicate that the PUP transport system also exists in rice, and OsPUP7 has an important role in the transport of CK, thus affecting developmental process and stress responses.

  9. Identification and quantification of phytochelatins in roots of rice to long-term exposure: evidence of individual role on arsenic accumulation and translocation

    Lemos Batista, Bruno; Nigar, Meher; Mestrot, Adrien; Alves Rocha, Bruno; Barbosa Júnior, Fernando; Price, Adam H.; Raab, Andrea; Feldmann, Jörg

    2014-01-01

    Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and As–PC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, ...

  10. Enhanced viral pathogenesis associated with a virulent mutant virus or a virulent satellite RNA correlates with reduced virion accumulation and abundance of free coat protein

    SatC, a chimeric satellite RNA associated with Turnip crinkle virus (TCV), intensifies the symptoms of TCV on all symptomatic hosts yet attenuates the symptoms of a TCV mutant that expresses low levels of a defective coat protein (CP). We now report that TCV virion levels were substantially reduced by the presence of satC or when two amino acids were inserted at the N-terminus of the CP, resulting in similarly enhanced symptoms. Since the TCV CP is a suppressor of RNA silencing, increased levels of resultant free CP could augment silencing suppression, resulting in enhanced colonization of the plant

  11. 水稻花器官数目突变体fon6的研究初报%A Preliminary Study on the Floral Organ Number Mutant fon6 in Rice

    赵福永; 王洁雅; 黄显波; 邓则勤; 林成豹; 严寒; 田志宏

    2011-01-01

    fon6是在籼稻恢复系乐恢188/明恢62杂交F3代发现的花器官数目突变体,表型分析结果表明:该突变体小花颖壳畸形扭曲、内颖长于外颖不闭合;每朵小花内外颖壳总数目2~4片;雄蕊数目为1~14枚;雌蕊数目增加,子房数目2~6个,胚囊畸形.突变体套袋自交结实率为14.06%,花粉活力较高,平均花粉可染率为91.86%.自交种子能正常萌发成苗,突变性状表现稳定的遗传特性.以突变体为父本分别与蜀恢527、明恢63杂交,F2代群体中正常株与突变株的分离均符合3:1的比例,F3代及BC1,F2代进一步的观察与统计结果均表明,该突变性状受1对隐性核基因控制,将该突变基因暂定名为fon6 (floral organ number 6).%fon6 is a mutant in the number of floral organs of rice discovered in the F3 generation of the cross Lehui 188/Minghui 62.The survey on morphology showed that it had a malformed floret with open twisted glumes, there were 2 ~4 paleae and lemmas, 1 ~ 14 stamens, more pistils with 2 ~6 ovaries and malformed embryo sacs in a floret.The mutant had a lower selfed seed set at 14.06% but a high pollen vigor with 91.86% of averaged I2-KI stained pollen rate.The selfed seed could germinate and grow into seedlings normally.The mutant trait was inheritable.The F2 generation of the crosses of the mutant as the male with Shuhui 527 and Minghui 63 as the female showed a segregation ratio of 3∶1 between normal and mutant plants.Moreover, the investigation on the segregation ratio in the trait of their F3 and BC 1 F2 populations was also conducted.The results of the genetic analysis indicated that the mutant trait was controlled by one pair of recessive nucleic genes.The mutant gene was tentatively designated as fon6 ( floral organ number 6).

  12. Padrão de integração de pAN7-1 em mutantes de Magnaporthe grisea com patogenicidade alterada em arroz pAN7-1 integration pattern in mutants of Magnaporthe grisea impaired in pathogenicity to rice

    Carlos Eduardo Marchi

    2010-03-01

    Full Text Available Ensaios foram conduzidos para verificar a presença, o número de cópias e de sítios de integração de pAN7-1 no genoma de mutantes de M. grisea I-22 com patogenicidade alterada em arroz. Foram analisados T41, T93, T251 (gerados por mutagênese REMI e T108 (oriundo de mutagênese convencional, os quais exibiram diferentes fenótipos mutantes. O DNA total desses mutantes foi submetido à reação em cadeia de polimerase (PCR e às análises de hibridização com o vetor (Southern blot. A presença de pAN7-1 no genoma de todos os mutantes foi confirmada por PCR. Segundo as análises de Southern blot, T41 exibiu duas integrações do vetor, ambas na forma de cópia única. No genoma de T93 também foram detectados dois sítios de inserção de pAN7-1, um dos quais envolvendo múltiplas cópias do vetor. Os resultados indicaram a presença de apenas uma cópia do vetor em um único sítio nos genomas de T108 e T251. O padrão de integração em T251 foi o único a sugerir a ocorrência de evento REMI. As diferenças quanto ao tamanho dos fragmentos com homologia a pAN7-1 refletiram a possível aleatoriedade dos eventos de integração no genoma de M. grisea. Os resultados evidenciaram o potencial de REMI para a mutagênese insercional de M. grisea, quando conduzida com pAN7-1 e HindIIIExperiments were conducted to investigate the presence, number of copies and integration site of pAN7-1 in the genome of mutants of Magnaporthe grisea impaired in pathogenicity to rice. The mutants T41, T93, T251 (obtained by REMI and T108 (obtained by conventional mutagenesis exhibiting different alterations in pathogenicity were analyzed. Polymerase chain reaction (PCR and Southern blot analyses were conducted with total DNA of mutants. The presence of pAN7-1 in genome of mutants was confirmed by PCR. Based in Southern blot analyses, two single-copy integration of vector were detected in T41. Two insertion sites of pAN7-1 were detected in the genome of T93

  13. Overexpression of an endo-1,4-β-glucanase V gene (EGV) from Trichoderma reesei leads to the accumulation of cellulase activity in transgenic rice.

    Li, X Y; Liu, F; Hu, Y F; Xia, M; Cheng, B J; Zhu, S W; Ma, Q

    2015-01-01

    The ectopic expression of cellulase in biomass can reduce the cost of biofuel conversion. This trait modification technique is highly beneficial for biofuel production. In this study, we isolated an endo-1,4-beta-glucanase gene (EGV) from Trichoderma reesei and inserted this gene downstream of a fragment encoding the signal peptide Apo-SP in a modified pCAMBIA1301 vector to obtain an Apo-SP and AsRed fusion protein. Transient expression of this fusion protein in onion epidermal cells showed that the Apo-SP signal was localized to the plastids. EGV transgenic rice plants that did not carry screening marker genes were obtained through overexpression of the pDTB double T-DNA vector. Western blotting showed that EGV was expressed in the dry straw of T0 generation transgenic rice plants and in fresh leaves of the T1 generation. More importantly, our results also showed that the peptide product of EGV in the transgenic plants folded correctly and was capable of digesting the cellulase substrate CMC. Additionally, cellulase activity remained stable in the straw that had been dried at room temperature for three months. This study presents an important technical approach for the development of transgenic rice straw that has stable cellulase activity and can be used for biofuel conversion. PMID:26782396

  14. PHENOTYPIC,GENETIC ANALYSIS AND BR RESPONSE OF A RICE DOUBLE FLAG LEAF(dfl1) MUTANT%水稻双剑叶突变体的表型、遗传分析及BR应答

    祁永斌; 杨卫兵; 叶胜海; 刘合芹; 金庆生; 何祖华; 张小明

    2012-01-01

    从浙江省主栽晚粳稻品种浙粳22的辐照突变体库中,发现1株分蘖穗穗颈节上着生2片叶片的突变体,多代种植性状稳定,且不受环境条件影响。鉴定结果表明该突变体是由于倒1节间显著缩短所致,其籽粒比野生型略短,剑叶净光合速率、气孔导度、胞间CO2浓度等光合作用参数均低于野生型;突变表型受1对隐性基因控制,对外源油菜素内酯(BR)敏感。RT-PCR结果表明,部分BR合成和代谢相关基因在突变体和野生型中的表达量有差异,推测该突变基因与BR合成和代谢相关。%A rice mutant designated as dfl1 bearing pseudo-two-flag-leaves on the uppermost internode was found from the irradiation mutant library of var.Zhejing 22 mainly cultivated in the Zhejiang Province.The traits of dfl1 were stable after multiple generation of selfcrossing.Our results showed that its second internode from top and seed length were shortened.Net photosynthetic rate,stomata conductance and intercellular CO2 concentrations were all reduced compared with the wild type ZJ22.The characteristics of dfl1 were decided by a pair of recessive gene.Dfl1 was sensitive to exogenous brassinosteroid(BR),and the expression of several BR genes related to synthesis and metabolism was different from wild type.Together,we speculated that dfl1 mutant was related to synthesis and metabolism of endogenous BR.

  15. An elite restorer mutant R3027 induced by the integral application of γ-rays irradiation and somaclonal variation techniques

    Series of somaclonal variants were induced from young inflorescence culture of single season indica rice 3027, which was irradiated by 15 Gy γ-rays and then transferred onto fresh N6 medium for callus formation and MS medium for shoot differentiation. One early maturing restorer mutant, named as R3027, was identified and found to possess the obviously improved multiple agronomic traits and combined ability in comparison with the original parent 3027. A new hybrid rice cultivar, II you 3027, with the highest yield potential of 10477 kg/hm2 was successfully bred from the cross between the cytoplasmic male sterile line II-32A and mutant R3027. This new cultivar was officially released in April, 2000 in Zhejiang province, and its accumulative planting areas reached 200 khm2

  16. Influence of Phosphate Fertilizer on Hg Accumulation in the Soil-Rice System%施磷肥对土壤-水稻体系中Hg迁移累积规律的影响

    王洪君; 王楠; 梁烜赫; 张磊; 曹玉军; 陈宝玉

    2011-01-01

    对水稻田施用不同剂量磷肥,定期测定土壤、水稻根、茎、叶和子粒中的Hg的动态变化,研究Hg在土壤和水稻各器官中的分配累积、动态变化规律,以及Hg在土壤和水稻植株各器官的累积量与磷肥施用量的相关性等.结果表明:在水稻成熟期,在4个不同磷肥水平下,土壤和植株中Hg的含量与磷肥施用量存在明显的剂量效应,Hg在土壤及水稻植株不同器官的含量分布由大到小的次序为土壤>根>茎>叶>穗;叶、穗中重金属Hg含量总体趋势为先升高后下降,根中重金属Hg含量除10月初出现几个高值外,总体趋势为平稳,茎中重金属Hg含量总体趋势为下降;Hg在土壤和水稻各器官累积量与磷肥施用量达到极显著相关;Hg在水稻植株体内富集系数为根>茎>叶>穗.%In this study rice was treated with different doses of phosphate, Hg in soil and various organs of rice were analyzed by dynamic measurement. The rules of distribution and accumulation, dynamic change and the correlation of cumulative between heavy meals and soil and rice organs under different lev els of phosphate were studied. The results showed: in mature stage, the content of Hg in soil and plants related to phosphate exists a clear dose-response under four different levels of phosphate. The distribution of Hg in soil and rice plants with different organs was as follows: soil > root > stem > leave > ear. The trend of Hg content in root was smooth in addition to a few high-value occurred in early October. The trend of Hg content in stem was declined, and in leaf and ear was first increased and then decreased. The accumulated contention of Hg in soil and various organs of rice reached a very significant correlation with phosphate fertilization. The enrichment rule of Hg in soil-rice system under different levels of phosphate:root > stem > leave > ear.

  17. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize.

    Wu, Xiaolin; Gong, Fangping; Yang, Le; Hu, Xiuli; Tai, Fuju; Wang, Wei

    2014-01-01

    ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5), deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs), late embryogenesis abundant (LEA) proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation. PMID:25653661

  18. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize

    Xiaolin eWu

    2015-01-01

    Full Text Available ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5, deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs, late embryogenesis abundant (LEA proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation.

  19. A Rice Phytochrome A in Arabidopsis: The Role of the N-terminus under red and far-red light

    Julia Kneissl; Tomoko Shinomura; Masaki Furuya; Cordelia Bolle

    2008-01-01

    The phytochrome (phy)A and phyB photoreceptors mediate three photobiological response modes in plants;whereas phyA can mediate the very-Iow-fluence response (VLFR), the high-irradiance response (HIR) and, to some extent, the low fluence response (LFR), phyB and other type Ⅱ phytochromes only mediate the LFR. To investigate to what level a rice phyA can complement for Arabidopsis phyA or phyB function and to evaluate the role of the serine residues in the first 20 amino acids of the N-terminus of phyA, we examined VLFRo LFR, and HIR responses in phyB and phyAphyB mutant plants transformed with rice PHYA cDNA or a mutant rice PHYA cDNA in which the first 10 serine residues were mutated to alanines (phyA SA). Utilizing mutants without endogenous phyB allowed the evaluation of red-light-derived responses sensed by the rice phyA. In summary, the WT rice phyA could complement VLFR and LFR responses such as inhibition of hypocotyl elongation under pulses of FR or continuous R light, induction of flowering and leaf expansion, whereas the phyA SA was more specific for HIR responses (e.g. inhibition of hypocotyl elongation and anthocyanin accumulation under continuous far-red light). As the N-terminal serines can no longer be phosphorylated in the phyA SA mutant, this suggests a role for phosphorylation discriminating between the different phyA-dependent responses. The efficacy of the rice phyA expressed in Arabidopsis was dependent upon the developmental age of the plants analyzed and on the physiological response, suggesting a stage-dependent downstream modulation of phytochrome signaling.

  20. Effects of phosphorus and silicon applications on arsenic accumulation in rice grains in South China%磷硅肥配施抑制华南地区水稻籽粒砷积累的效果

    张琳; 卢瑛

    2016-01-01

    Phosphorus(P)and silicon(Si)have showed the ability to reduce arsenic(As)uptake by plants from soils. Here a pot experiment was conducted in a soil spiked with 50 mg·kg-1 arsenic to study the effects of different rates of phosphorus and silicon fertilizers on growth and arsenic accumulation of a hybrid rice cultivar, PeizaTaifeng, which is widely planted in South China. Results showed that after applica-tions of phosphorus and silicon fertilizers,arsenic content in rice grains ranged from 0.504 to 0.586 mg·kg-1, lower than the limit of arsenic in rice grains(NY 861—2004)enacted by the China Ministry of Agriculture. Correlation analyses showed that arsenic content in rice grains had significantly negative correlation with rice plant biomass, thousand seed weight, Si/As molar ratio in straw, and extremely significant negative correlation with P/As molar ratio in straw. Arsenic concentrations in grains decreased with increasing rates of phosphorus and sili-con fertilizers. The present findings suggest that the optimum application rates of phosphorus and silicon fertilizers for rice grown in arsenic polluted soil would be 40 mg P·kg-1 soil and 50 mg Si·kg-1 soil in the South China area.%选取华南地区广泛种植的杂交水稻品种“培杂泰丰”,利用外源添加砷(50 mg·kg-1)的土壤盆栽试验,研究不同施用量的磷硅肥对水稻生长特性和砷积累的影响。结果表明,施用磷硅肥的处理,水稻糙米中砷含量为0.504~0.586 mg·kg-1,低于农业部颁布的粮食中砷限量标准(NY 861—2004)中大米砷限值。相关性分析表明,水稻糙米砷含量与水稻植株的生物量、稻谷千粒重和秸秆中硅/砷摩尔比呈显著负相关,与秸秆中磷/砷摩尔比呈极显著负相关;糙米的砷含量随磷、硅肥的施加而降低。综合分析表明,在华南地区同类中度砷污染土壤中可有效控制砷向水稻籽粒运输累积的磷、硅肥

  1. Identification of a peroxisomal-targeted aldolase involved in chlorophyll biosynthesis and sugar metabolism in rice.

    Zhang, Fei; Zhang, Pan; Zhang, Yu; Wang, Shouchuang; Qu, Lianghuan; Liu, Xianqing; Luo, Jie

    2016-09-01

    Chlorophyll plays remarkable and critical roles in photosynthetic light-harvesting, energy transduction and plant development. In this study, we identified a rice Chl-deficient mutant, ygdl-1 (yellow green and droopy leaf-1), which showed yellow-green leaves throughout plant development with decreased content of Chls and carotene and an increased Chl a/b ratio. The ygdl-1 mutant also exhibited severe defects in chloroplast development, including disorganized grana stacks. Sequence analysis revealed that the mutant contained a T-DNA insertion within the promoter of a fructose-1,6-bisphosphate aldolase (OsAld-Y), which dramatically reduced the OsAld-Y mRNA level, and its identity was verified by transgenic complementation. Real-time PCR analysis showed that the expression levels of genes associated with chlorophyll biosynthesis and chloroplast development were concurrently altered in the ygdl-1 mutant. The expression of OsAld-Y-GFP fusion protein in tobacco epidermal cells showed that OsAld-Y was localized to the peroxisome. In addition, the analysis of primary carbon metabolites revealed the significantly reduced levels of sucrose and fructose in the mutant leaves, while the glucose content was similar to wild-type plants. Our results suggest that the OsAld-Y participates in Chl accumulation, chloroplast development and plant growth by influencing the photosynthetic rate of leaves and the sugar metabolism of rice. PMID:27457997

  2. Identification and quantification of phytochelatins in roots of rice to long-term exposure: evidence of individual role on arsenic accumulation and translocation.

    Batista, Bruno Lemos; Nigar, Meher; Mestrot, Adrien; Rocha, Bruno Alves; Barbosa Júnior, Fernando; Price, Adam H; Raab, Andrea; Feldmann, Jörg

    2014-04-01

    Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and As-PC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, 9524, Kitrana 508, YRL-1, and Lemont) exposed to low and high levels of i-As were compared with total, i-As, and o-As in roots, shoots, and grains. Only Dom Sofid, Kitrana 508, and 9524 were found to produce higher levels of PCs even when exposed to low levels of As. PCs were only correlated to i-As in the roots (r=0.884, P <0.001). However, significant negative correlations to As transfer factors (TF) roots-grains (r= -0.739, P <0.05) and shoots-grains (r= -0.541, P <0.05), suggested that these peptides help in trapping i-As but not o-As in the roots, reducing grains' i-As. Italica Carolina reduced i-As in grains after high exposure, where some specific PCs had a special role in this reduction. In Lemont, exposure to elevated levels of i-As did not result in higher i-As levels in the grains and there were no significant increases in PCs or thiols. Finally, the high production of PCs in Kitrana 508 and Dom Sofid in response to high As treatment did not relate to a reduction of i-As in grains, suggesting that other mechanisms such as As-PC release and transport seems to be important in determining grain As in these cultivars. PMID:24600019

  3. Unexpected accumulation of ncm(5U and ncm(5S(2 (U in a trm9 mutant suggests an additional step in the synthesis of mcm(5U and mcm(5S(2U.

    Changchun Chen

    Full Text Available BACKGROUND: Transfer RNAs are synthesized as a primary transcript that is processed to produce a mature tRNA. As part of the maturation process, a subset of the nucleosides are modified. Modifications in the anticodon region often modulate the decoding ability of the tRNA. At position 34, the majority of yeast cytosolic tRNA species that have a uridine are modified to 5-carbamoylmethyluridine (ncm(5U, 5-carbamoylmethyl-2'-O-methyluridine (ncm(5Um, 5-methoxycarbonylmethyl-uridine (mcm(5U or 5-methoxycarbonylmethyl-2-thiouridine (mcm(5s(2U. The formation of mcm(5 and ncm(5 side chains involves a complex pathway, where the last step in formation of mcm(5 is a methyl esterification of cm(5 dependent on the Trm9 and Trm112 proteins. METHODOLOGY AND PRINCIPAL FINDINGS: Both Trm9 and Trm112 are required for the last step in formation of mcm(5 side chains at wobble uridines. By co-expressing a histidine-tagged Trm9p together with a native Trm112p in E. coli, these two proteins purified as a complex. The presence of Trm112p dramatically improves the methyltransferase activity of Trm9p in vitro. Single tRNA species that normally contain mcm(5U or mcm(5s(2U nucleosides were isolated from trm9Δ or trm112Δ mutants and the presence of modified nucleosides was analyzed by HPLC. In both mutants, mcm(5U and mcm(5s(2U nucleosides are absent in tRNAs and the major intermediates accumulating were ncm(5U and ncm(5s(2U, not the expected cm(5U and cm(5s(2U. CONCLUSIONS: Trm9p and Trm112p function together at the final step in formation of mcm(5U in tRNA by using the intermediate cm(5U as a substrate. In tRNA isolated from trm9Δ and trm112Δ strains, ncm(5U and ncm(5s(2U nucleosides accumulate, questioning the order of nucleoside intermediate formation of the mcm(5 side chain. We propose two alternative explanations for this observation. One is that the intermediate cm(5U is generated from ncm(5U by a yet unknown mechanism and the other is that cm(5U is formed

  4. Spatio-temporal reconstruction of air temperature maps and their application to estimate rice growing season heat accumulation using multi-temporal MODIS data

    Li-wen ZHANG; Jing-feng HUANG; Rui-fang GUO; Xin-xing LI; Wen-bo SUN; Xiu-zhen WANG

    2013-01-01

    The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(Ta)and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs)calculation from remotely sensed data,a novel spatio-temporal algorithm for Ta estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS)data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs)above 10 ℃,from reconstructed Ta based on MODIS land surface temperature(LST)data.The verification results of maximum Ta,minimum Ta,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.

  5. Acúmulo de silício em plantas de arroz do ecossistema de várzea submetido à aplicação de diferentes fontes Sources and accumulation of silicon in plants of lowland rice

    Lucélia Alves Ramos

    2008-01-01

    the dose of 200 mg kg-1 of Si. The curve of response to Si was established by application of a standard source (Wollastonite in the doses of 0, 50, 100, 200, 400 mg kg-1 of Si, seeking to obtain a curve of response. The rice cultivar Rio formoso was sown and the production of dry mass of the aerial part, panicles mass, production of grains, plant tissue and soil Si content, were determined by the rice cycle. The standard source Wollastonite had linear behavior, increasing soil Si availability and its absorption by rice with the increase of the applied doses. The largest increases in the contents of Si in the aerial part, in the peel, and Si accumulated in the plant and Si in the dry total mass were produced by Wollastonite. The source that provided larger increase in the yield of grains was silicon in the powder form. The acetic acid extracted larger amount of Si of the soil than calcium chloride, overestimating the results.

  6. Impact of mutation breeding in rice

    More cultivars have been developed in rice through the use of mutation breeding than in any other crop. Direct releases of mutants as cultivars began some 30 years ago, and now total 198 cultivars. During the last 20 years, increasing use has been made of induced mutants in cross-breeding programs, leading to 80 additional cultivars. Principal improvements through mutation breeding have been earlier maturity, short stature, and grain character modifications. Rice has been a popular subject of mutagenesis because it is the world's leading food crop, has diploid inheritance, and is highly self-pollinated. In recent years induced mutation has been exploited to develop breeding tool mutants, which are defined as mutants that in themselves may not have direct agronomic application but may be useful genetic tools for crop improvement. Examples include the eui gene, hull colour mutants, normal genetic male steriles, and environmentally sensitive genetic male steriles. The environmentally sensitive genetic male steriles, especially those in which male sterility can be turned on or off by different photoperiod lengths, show promise for simplifying hybrid rice seed production both in China and the USA. Future applications of mutation in rice include induction of unusual endosperm starch types, plant types with fewer but more productive tillers, dominant dwarfs, dominant genetic male steriles, extremely early maturing mutants, nutritional mutants, and in vitro-derived mutants for tolerance to herbicides or other growth stresses. Refs, 4 figs, 2 tabs

  7. Improvement of rice through induced mutations

    In this report four semidwarf mutants of rice were evaluated for their physicochemical and milling characteristics. The results shows that all the mutants as well as Basmati 370 are less bursting during cooking as compared to Basmati 385. Plant breeding behavior and quality characters for relatively salt tolerant and grain yield has also been discussed in this report. (A.B.)

  8. Spatio-temporal reconstruction of air temperature maps and their application to estimate rice growing season heat accumulation using multi-temporal MODIS data*

    Zhang, Li-Wen; Huang, Jing-feng; Guo, Rui-fang; Li, Xin-xing; Sun, Wen-bo; Wang, Xiu-zhen

    2013-01-01

    The accumulation of thermal time usually represents the local heat resources to drive crop growth. Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity. To solve the critical problems of estimating air temperature (T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days (GDDs) calculation from remotely sensed data, a no...

  9. Cardiolipin molecular species with shorter acyl chains accumulate in Saccharomyces cerevisiae mutants lacking the acyl coenzyme A-binding protein Acb1p: new insights into acyl chain remodeling of cardiolipin.

    Rijken, Pieter J; Houtkooper, Riekelt H; Akbari, Hana; Brouwers, Jos F; Koorengevel, Martijn C; de Kruijff, Ben; Frentzen, Margrit; Vaz, Frédéric M; de Kroon, Anton I P M

    2009-10-01

    The function of the mitochondrial phospholipid cardiolipin (CL) is thought to depend on its acyl chain composition. The present study aims at a better understanding of the way the CL species profile is established in Saccharomyces cerevisiae by using depletion of the acyl-CoA-binding protein Acb1p as a tool to modulate the cellular acyl chain content. Despite the presence of an intact CL remodeling system, acyl chains shorter than 16 carbon atoms (C16) were found to accumulate in CL in cells lacking Acb1p. Further experiments revealed that Taz1p, a key CL remodeling enzyme, was not responsible for the shortening of CL in the absence of Acb1p. This left de novo CL synthesis as the only possible source of acyl chains shorter than C16 in CL. Experiments in which the substrate specificity of the yeast cardiolipin synthase Crd1p and the acyl chain composition of individual short CL species were investigated, indicated that both CL precursors (i.e. phosphatidylglycerol and CDP-diacylglycerol) contribute to comparable extents to the shorter acyl chains in CL in acb1 mutants. Based on the findings, we conclude that the fatty acid composition of mature CL in yeast is governed by the substrate specificity of the CL-specific lipase Cld1p and the fatty acid composition of the Taz1p substrates. PMID:19656950

  10. Compartmentation and dynamics of flavone metabolism in dry and germinated rice seeds.

    Galland, Marc; Boutet-Mercey, Stéphanie; Lounifi, Imen; Godin, Béatrice; Balzergue, Sandrine; Grandjean, Olivier; Morin, Halima; Perreau, François; Debeaujon, Isabelle; Rajjou, Loïc

    2014-09-01

    Among secondary metabolites, flavonoids are particularly important for the plant life cycle and could be beneficial for human health. The study of Arabidopsis thaliana transparent testa mutants showed that seed flavonoids are important for environmental adaptation, reactive oxygen species homeostasis, dormancy and longevity. Compared with Arabidopsis and maize (Zea mays L.), far less research has been conducted on rice (Oryza sativa L.) particularly for cultivars with non-pigmented seeds. In this study, we describe the localization, nature and relative abundance of flavonoids in mature and germinated non-pigmented Nipponbare seeds using a combination of confocal microscopy, mass spectrometry and gene expression analysis. The mature seed exclusively accumulates flavones mostly in the embryo and to a lesser extent in the pericarp/testa. Due to the variety of flavone conjugation patterns, 21 different flavones were identified, including sulfated flavones never mentioned before in cereals. Schaftoside (apigenin-6-C-glucoside-8-C-arabinoside) and its two isomers represent nearly 50% of all rice seed flavones and are the only flavonoids accumulated in the pericarp/testa seed compartment. These 21 conjugated flavones showed a very stable profile during rice seed germination sensu stricto, while expression of key flavone synthesis genes strongly increases before the completion of germination. We discuss the potential roles of these rice seed flavones in a seed biology context. PMID:25008975

  11. Functions of Phytochrome in Rice Growth and Development

    Gu Jian-wei; LIU Jing; XUE Yan-jiu; ZANG Xin; XIE Xian-zhi

    2011-01-01

    Phytochrome family mainly senses rod and far-red light to regulate a range of developmental processes throughout the life cycle of plants.Rice phytochrome gene family is composed of three members known as PHYA,PHYB and PHYC.It has been elucidated that individual phytochromes display both unique and overlapping roles in rice photomorphogenesis by characterization of all rice phytochrome mutants including single mutants,all combinations of double mutants as well as triple mutants.Based on the published data and authors' ongoing studies,current knowledge of rice phytochrome functions in regulating seedling de-etiolation,root gravitropic response and elongation,plant architecture,flowering time and fertility is summarized.Additionally,the important issues in the field of rice phytochromes are proposed.

  12. Smoke Priming, a Potent Protective Agent Against Salinity: Effect on Proline Accumulation, Elemental Uptake, Pigmental Attributes and Protein Banding Patterns of Rice (Oryza Sativa)

    Jamil, Muhammad; Malook, Ijaz; Parveen, Salma; Naz, Tayybah; Ali, Arshad; Ullah Jan, Sami; ur Rehman, Shafiq

    2013-01-01

    The exogenous application of plant derived smoke solution through seed pre treatment is consider to create tolerance in the plant against salinity, for this purpose different dilution of plant derived smoke solution as 1:5000 Buhania, 1:1000 Buhania, 1:1000 Cymbopogon, 1:500 Cymbopogon were used against 0 mM, 50, 100 and 150mM NaCl solution in the medium. The effect was observed on total proline accumulation, heavy metals uptake, photosynthetic pigments and protein poly peptide bands intensit...

  13. Induced mutagenesis in rice in Colombia

    Three rice varieties (CICA-8, Oryzica-I and Oryzica-2) were treated with gamma rays to induce blast resistant mutants. Mutant lines were selected from CICA-8 and Oryzica-1 that in the preliminary test showed yield differences between the original variety and the selected lines. Although blast infection scores were similar for the checks and the mutant lines, the lines are useful for non-endemic blast areas because of their good agronomic traits. (author). 1 ref., 3 tabs

  14. Gibberellin Signal Transduction in Rice

    Liu-Min Fan; Xiaoyan Feng; Yu Wang; Xing Wang Deng

    2007-01-01

    In the past decade, significant knowledge has accumulated regarding gibberellin (GA) signal transduction in rice as a result of studies using multiple approaches, particularly molecular genetics. The present review highlights the recent developments in the identification of GA signaling pathway components, the discovery of GA-induced destruction of GA signaling represser (DELLA protein), and the possible mechanism underlying the regulation of GA-responsive gene expression in rice.

  15. PIXE analyses of cesium in rice grains

    Sugai, Hiroyuki; Ishii, Keizo; Matsuyama, Shigeo; Terakawa, Atsuki; Kikuchi, Yohei; Takahashi, Hiroaki; Ishizaki, Azusa; Fujishiro, Fumito; Arai, Hirotsugu; Osada, Naoyuki; Karahashi, Masahiro; Nozawa, Yuichiro; Yamauchi, Shosei; Kikuchi, Kosuke; Koshio, Shigeki; Watanabe, Koji

    2014-01-01

    The Fukushima nuclear power plant accident released vast amounts of radioactive material into the environment. For instance, 134Cs and 137Cs have half-lives of about 2 and 30 years, respectively, and emit many harmful gamma rays. In 2012, rice with radioactivity >100 Bq/kg was occasionally reported in Fukushima prefecture. To determine where and how cesium accumulates in rice, we grew rice in soil containing stable cesium and investigated the distribution of cesium in rice using particle-induced X-ray emission (PIXE). This study found that cesium is accumulated in bran and germ at high concentrations, and white rice contains 40% of the cesium found in brown rice.

  16. Acúmulo de massa seca em três cultivares de arroz irrigado com diferentes arquiteturas de plantas Dry matter accumulation by three flooded rice cultivars with different plant canopy

    Juçara Terezinha Paranhos

    1995-01-01

    Full Text Available O experimento foi conduzido em Planossolo da Unidade de Mapeamento Vacacaí, com o ohjetivo de estudar o acúmulo de massa seca nos diversos órgãos da planta de três cultivares de arroz irrigado (EEA 406, Bluebelle e BR-IRGA 409, utilizando-se delineamento de blocos ao acaso com cinco repetições. A massa seca foi obtida em sete estádios fenológicos da cultura. Desconsiderando os grãos e panículas, a EEA 406 possui maior capacidade produtiva de fitomassa, sendo a Bluebelle menos produtiva. Na maturação, a cultivar BR-IRGA 409 apresentou maior massa seca total, demonstrando maior capacidade de alocar assimilados nos grãos e maior eficiência de conversão de energia solar em fitomassa, sendo a Bluebelle menos eficiente. Para as três cultivares, até a floração, o colmo acumulou a maior percentagem de massa seca sendo, a partir daí, substituído pelas panículas e grãos. O máximo acúmulo de massa seca nas raízes ocorreu por ocasião da floração, cerca de 80 dias após a emergência.This experiment was carried out in an Halbaqualf soil to study the dry matter accumulation of three flooded rice cultivars. A complete randomized block design was used, with tive replication. Plant dry matter was measured in seven different growth stages. The cultivar EEA 406 had a higherdry matter accumulation than the cultivar Bluebelle without including grain and panicle. At maturity, the BR-IRGA 409 cultivar showed higher total dry matter. This demonstrate a better capacity of this variety in alocating assimilates into grains a higher effíciency in converting solar energy into plant biomass. The Bluebelle had lower efficiency. The dry matter accumulation increased for the three varieties from seeding to flowering into colm and, from flowering to harvest into panicles and grain. The maximum dry matter accumulation in roots was observed at flowering, eighty days after emergency.

  17. Production and accumulation of UV-B [ultra violet] absorbing compounds in UV-B irradiated leaves of rice, Oryza SativaL.: effects of varying UV-B doses on leaf damage, phenolic content and HPLC [high performance liquid chromatography] peak I area

    The effects of varying UV-B doses on leaf damage, phenolic content and HPLC peak 1 area were studied using 65-d-old plants of the UV-B tolerant rice cultivar, M202, and the UV-B susceptible rice cultivar, Dular. Results showed that the production and accumulation of UV-B- absorbing compounds in rice leaves were affected by leaf position and levels (dose) of UV-B and time or duration of UV-B irradiation or exposure. The youngest terminal leaves showed the least damage when exposed to medium and high UV-B doses. The production of these absorptive compounds as represented by relative phenolic and HPLC peak 1 were significantly higher in younger leaves and lower in older or senescing leaves. M202 showed significantly higher amounts of peak 1 area and relative phenolic compared to UV-B susceptible rice cultivar, Dular. The results also confirmed the strong relationship of overall damage rating and area of HPLC peak 1. The development of UV-B symptoms in the susceptible cultivar was hastened when a high UV-B treatment was applied. Peak 1 area did not accumulate in the UV-B susceptible Dular at any given UV-B dose

  18. The potential bioproduction of the pharmaceutical agent sakuranetin, a flavonoid phytoalexin in rice.

    Shimizu, Takafumi; Lin, Fengqiu; Hasegawa, Morifumi; Nojiri, Hideaki; Yamane, Hisakazu; Okada, Kazunori

    2012-01-01

    Sakuranetin, the major flavonoid phytoalexin in rice, can be induced by ultraviolet (UV) irradiation, treatment with CuCl 2 or jasmonic acid (JA), or phytopathogenic infection. In addition to sakuranetin's biological significance on disease resistance in rice, its broad bioactivities have recently been described. Results from these studies have shown that sakuranetin is a useful compound as a plant antibiotic and a potential pharmaceutical agent. Sakuranetin is biosynthesized from naringenin, a precursor of sakuranetin, by naringenin 7-O-methyltransferase (NOMT), but the relevant gene has not yet been identified in rice. Recently, we identified the OsNOMT gene, which is involved in the final step of sakuranetin biosynthesis in rice. In previous studies, OsNOMT was purified to apparent homogeneity from UV-treated wild-type rice leaves; however, the purified protein, termed OsCOMT1, exhibited caffeic acid 3-O-methyltransferase (COMT) activity, but not NOMT activity. Based on the analysis of an oscomt1 T-DNA tagged mutant, we determined that OsCOMT1 did not contribute to sakuranetin production in rice in vivo. Therefore, we took advantage of the oscomt1 mutant to purify OsNOMT. A crude protein preparation from UV-treated oscomt1 leaves was subjected to three sequential purification steps resulting in a 400-fold purification from the crude enzyme preparation with a minor band at an apparent molecular mass of 40 kDa in the purest enzyme preparation. Matrix-assisted laser desorption/ionization time of flight/time of flight analysis showed that the 40 kDa protein band included two O-methyltransferase-like proteins, but one of the proteins encoded by Os12g0240900 exhibited clear NOMT activity; thus, this gene was designated OsNOMT. Gene expression was induced by treatment with jasmonic acid in rice leaves prior to sakuranetin accumulation, and the recombinant protein showed reasonable kinetic properties to NOMT. Identification of the OsNOMT gene enables the production of

  19. Root hair mutants of barley

    Barley mutants without root hairs or with short or reduced root hairs were isolated among M2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M2 seeds were sown in the field the same day. Spikes, 4-6 per M1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

  20. Is there a second fragrance gene in rice?

    Fitzgerald, M.A.; Hamilton, N.R.S.; Calingacion, M.N.; Verhoeven, H.A.; Butardo, V.M.

    2008-01-01

    Aromatic rice is highly prized by most rice consumers, and many countries cultivate traditional and improved aromatic varieties. 2-Acetyl-1-pyrroline (2AP) is the major aromatic compound in rice, and is believed to accumulate because of an eight-base-pair (8-bp) deletion in an allele at the fragranc

  1. Overexpression of OsSAP16 Regulates Photosynthesis and the Expression of a Broad Range of Stress Response Genes in Rice (Oryza sativa L..

    Fei Wang

    Full Text Available This study set out to identify and characterize transcription factors regulating photosynthesis in rice. Screening populations of rice T-DNA activation lines led to the identification of a T-DNA mutant with an increase in intrinsic water use efficiency (iWUE under well-watered conditions. Flanking sequence analysis showed that the T-DNA construct was located upstream of LOC_Os07g38240 (OsSAP16 encoding for a stress-associated protein (SAP. A second mutant identified with activation in the same gene exhibited the same phenotype; expression of OsSAP16 was shown to be enhanced in both lines. There were no differences in stomatal development or morphology in either of these mutants, although overexpression of OsSAP16 reduced stomatal conductance. This phenotype limited CO2 uptake and the rate of photosynthesis, which resulted in the accumulation of less biomass in the two mutants. Whole transcriptome analysis showed that overexpression of OsSAP16 led to global changes in gene expression consistent with the function of zinc-finger transcription factors. These results show that the gene is involved in modulating the response of rice to drought stress through regulation of the expression of a set of stress-associated genes.

  2. Overexpression of OsSAP16 Regulates Photosynthesis and the Expression of a Broad Range of Stress Response Genes in Rice (Oryza sativa L.).

    Wang, Fei; Coe, Robert A; Karki, Shanta; Wanchana, Samart; Thakur, Vivek; Henry, Amelia; Lin, Hsiang-Chun; Huang, Jianliang; Peng, Shaobing; Quick, William Paul

    2016-01-01

    This study set out to identify and characterize transcription factors regulating photosynthesis in rice. Screening populations of rice T-DNA activation lines led to the identification of a T-DNA mutant with an increase in intrinsic water use efficiency (iWUE) under well-watered conditions. Flanking sequence analysis showed that the T-DNA construct was located upstream of LOC_Os07g38240 (OsSAP16) encoding for a stress-associated protein (SAP). A second mutant identified with activation in the same gene exhibited the same phenotype; expression of OsSAP16 was shown to be enhanced in both lines. There were no differences in stomatal development or morphology in either of these mutants, although overexpression of OsSAP16 reduced stomatal conductance. This phenotype limited CO2 uptake and the rate of photosynthesis, which resulted in the accumulation of less biomass in the two mutants. Whole transcriptome analysis showed that overexpression of OsSAP16 led to global changes in gene expression consistent with the function of zinc-finger transcription factors. These results show that the gene is involved in modulating the response of rice to drought stress through regulation of the expression of a set of stress-associated genes. PMID:27303811

  3. Microbial community response to two water management systems for wetland rice production in high arsenic soils

    Rice cultivation on arsenic (As) impacted soils has recently garnered considerable attention. Rice plants can accumulate As in grain, especially under the continuously flooded conditions commonly utilized in wetland-rice production. However, recent studies have indicated that rice-management system...

  4. Induced Mutations in Thai Rice

    Rice is the primary source of food for more than half of the world's population. It benefits greatly from technological inputs in the area of breeding such as induced mutation. Induced mutation can produce mutants with significant improvement in plant type, maturity, yields and protein ratio when compared to the parent. These improved traits enable the mutants to fit into farming systems with either shorter or longer growing seasons. Three induced mutant rice varieties, including RD6, RD10 and RD15, are well accepted by farmers and consumers in Thailand. RD6 and RD15 were aromatic, photosensitive varieties which were derived from KDML105 by acute irradiation of 20 and 15 kilorad gamma ray, respectively. After induced mutation, pedigree selection was applied. RD6 showed drought tolerance and also good grain quality including softness and good aroma with a higher average yield than the famous glutinous variety, San-Pah-Tong. Additionally, it was resistant to blast and brown spot diseases with an average yield of 4.19 tons/ha. RD15 showed drought tolerance and resistance to brown spot disease with the highest yield of 3.5 tons/ha. These two mutant varieties are currently the most famous aromatic rice varieties in Thailand. On the other hand, RD10 is a glutinous, photoperiod insensitive rice variety which was derived from RD1 by irradiation of 1 kilorad fast neutrons. RD10 showed good grain quality such as softness and stickiness with the yield of 4.25 tons/ha. As an on-going project, recommended rice varieties were irradiated with electron beam for anaerobic germination ability, submergence tolerance, stagnant-flood tolerance and also internode elongation.

  5. Cloning and characterization of the rice low phytic acid 1 gene

    The rice low phytic acid 1 (lpa1) mutant exhibits a 45% reduction in seed phytic acid with a molar-equivalent increase in inorganic phosphorus; however, it does not appear to differ significantly in productivity from its wild-type progenitor. Using a positional cloning strategy, we have identified a single candidate gene at the rice Lpa1 locus. Sequence analysis of the candidate gene from the original rice lpa1 mutant and a second recently identified lpa1 mutant revealed two independent mutations (a single base pair substitution and a single base pair deletion) that confirmed the identification of this candidate as the rice low phytic acid 1 gene, OsLpa1. The OsLpa1 gene has three expressed splice variants. The location and nature of the two mutations suggests that these lesions should only affect the translation of the predicted protein derived from the longest transcript. The proteins encoded by OsLpa1 do not have homology to any of the inositol phosphate metabolism genes characterized in plants to date, although there is homology to 2-phosphoglycerate kinase, an enzyme found in hyperthermophilic methanogens that catalyzes the formation of 2,3-bisphosphoglycerate from 2-phosphoglycerate. It has previously been shown that 2,3-bisphosphoglycerate is a competitive inhibitor of inositol polyphosphate 5-phosphatases. These phosphatases are known to breakdown inositol polyphosphate intermediates, suggesting a possible indirect role for OsLpa1 in phytic acid biosynthesis and accumulation. Functional analysis of OsLpa1 is underway and our progress will be reported. (author)

  6. MicroRNA393 is involved in nitrogen-promoted rice tillering through regulation of auxin signal transduction in axillary buds.

    Li, Xiang; Xia, Kuaifei; Liang, Zhen; Chen, Kunling; Gao, Caixia; Zhang, Mingyong

    2016-01-01

    Rice tillering has an important influence on grain yield, and is promoted by nitrogen (N) fertilizer. Several genes controlling rice tillering, which are regulated by poor N supply, have been identified. However, the molecular mechanism associated with the regulation of tillering based on N supply is poorly understood. Here, we report that rice microRNA393 (OsmiR393) is involved in N-mediated tillering by decreasing auxin signal sensitivity in axillary buds. Expression analysis showed that N fertilizer causes up-regulation of OsmiR393, but down-regulation of two target genes (OsAFB2 and OsTB1). In situ expression analysis showed that OsmiR393 is highly expressed in the lateral axillary meristem. OsmiR393 overexpression mimicked N-mediated tillering in wild type Zhonghua 11 (ZH11). Mutation of OsMIR393 in ZH11 repressed N-promoted tillering, which simulated the effects of limited N, and this could not be restored by supplying N fertilizer. Western blot analysis showed that OsIAA6 was accumulated in both OsmiR393-overexpressing lines and N-treated wild type rice, but was reduced in the OsMIR393 mutant. Therefore, we deduced that N-induced OsmiR393 accumulation reduces the expression of OsTIR1 and OsAFB2, which alleviates sensitivity to auxin in the axillary buds and stabilizes OsIAA6, thereby promoting rice tillering. PMID:27574184

  7. The Puzzle of Rice Domestication

    Tao Sang; Song Ge

    2007-01-01

    The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive differentiation and continuous gene flow within and between cultivated and wild rice. The long-standing controversy over single versus multiple and annual versus perennial origins of cultivated rice has been brought into shaper focus with the rapid accumulation of genetic and phylogenetic data. Molecular phylogenetic analyses revealed ancient genomic differentiation between rice cultivars, suggesting that they were domesticated from divergent wild populations. However, the recently cloned domestication gene sh4, responsible for the reduction of grain shattering from wild to cultivated rice, seems to have originated only once. Herein, we propose two models to reconcile apparently conflicting evidence regarding rice domestication. The snow-balling model considers a single origin of cultivated rice. In this model, a core of critical domestication alleles was fixed in the founding cultivar and then acted to increase the genetic diversity of cultivars through hybridization with wild populations. The combination model considers multiple origins of cultivated rice. In this model, initial cultivars were domesticated from divergent wild populations and fixed different sets of domestication alleles. Subsequent crosses among these semi-domesticated cultivars resulted in the fixation of a similar set of critical domestication alleles in the contemporary cultivars. In both models, introgression has played an important role in rice domestication. Recent and future introgression of beneficial genes from the wild gene pool through conventional and molecular breeding programs can be viewed as the continuation of domestication.

  8. Functional genomics strategies with transposons in rice

    Greco, R

    2003-01-01

    Rice is a major staple food crop and a recognizedmonocotylenedousmodel plant from which gene function discovery is projected to contribute to improvements in a variety of cereals like wheat and maize. The recent release of rough drafts of the rice genome sequence for public research provides a vast resource of gene sequences whose functions need to be determined by reverse genetics methods.Characterisation of a mutant phenotype is one of the most promising approaches to link gene to function....

  9. The tryptophan pathway is involved in the defense responses of rice against pathogenic infection via serotonin production.

    Ishihara, Atsushi; Hashimoto, Yumi; Tanaka, Chihiro; Dubouzet, Joseph G; Nakao, Takahito; Matsuda, Fumio; Nishioka, Takaaki; Miyagawa, Hisashi; Wakasa, Kyo

    2008-05-01

    The upregulation of the tryptophan (Trp) pathway in rice leaves infected by Bipolaris oryzae was indicated by: (i) enhanced enzyme activity of anthranilate synthase (AS), which regulates metabolic flux in the Trp pathway; (ii) elevated levels of the AS (OASA2, OASB1, and OASB2) transcripts; and (iii) increases in the contents of anthranilate, indole, and Trp. The measurement of the contents of Trp-derived metabolites by high-performance liquid chromatography coupled with tandem mass spectrometry revealed that serotonin and its hydroxycinnamic acid amides were accumulated in infected leaves. Serotonin accumulation was preceded by a transient increase in the tryptamine content and by marked activation of Trp decarboxylase, indicating that enhanced Trp production is linked to the formation of serotonin from Trp via tryptamine. Feeding of radiolabeled serotonin to inoculated leaves demonstrated that serotonin is incorporated into the cell walls of lesion tissue. The leaves of a propagating-type lesion mimic mutant (sl, Sekiguchi lesion) lacked both serotonin production and deposition of unextractable brown material at the infection sites, and showed increased susceptibility to B. oryzae infection. Treating the mutant with serotonin restored deposition of brown material at the lesion site. In addition, the serotonin treatment suppressed the growth of fungal hyphae in the leaf tissues of the sl mutant. These findings indicated that the activation of the Trp pathway is involved in the establishment of effective physical defenses by producing serotonin in rice leaves. PMID:18266919

  10. Characteristics of Arsenic Accumulation in Different Rice(Oryza sativa L. ) Cultivars and Its Influencing Factors in South China%华南地区不同品系水稻积累砷特征及其影响因素

    董飞; 卢瑛; 王兴祥; 闫秋艳; 张琳; 潘琦

    2011-01-01

    Sixteen conventional and hybrid rice( Oryza sativa L. ) cultivars, which are widely planted in South China, were used in a soil pot experiment to study arsenic absorption, transfer and accumulation and its influencing factors. The results showed that arsenic concentrations in rice tissue decreased in the order of root surface>root>straw>grain. Arsenic content in rice grain, ranged from 0.18 to 0.47 mg· kg-1, met national hygienic standard(GB 4810-1994); Arsenic content in iron and manganese plaques on root surface increased with the increase of root surface Fe and Mn contents, indicating that the formation of iron and manganese plaques could reduce grain arsenic accumulation; in addition, phosphorus levels could effectively reduce arsenic accumulation in straw. Arsenic content and transfer coefficient in different parts of hybrid rice were higher than those of conventional rice, with arsenic content in straw and grain reaching significant difference. Grain arsenic accumulation in Tianyou 122 was higher than other cultivars, whereas Meixiangzhan 2 was lower than others. The results suggested that arsenic concentration in rice grain could be decreased by means of screening rice cultivars with low arsenic accumulation and increasing P concentration in rice straw.%选用华南地区较为常见的杂交稻、优质常规稻2个水稻品系,16个水稻品种,通过土壤盆栽试验,待其成熟收获后,分析水稻根表、根部、秸秆、糙米中砷含量及相关影响元素的含量,旨在研究不同水稻品系(种)对砷吸收、转运和积累规律以及其影响因素,为低积累、高耐性水稻品系(品种)的选择及相应的农业措施提供科学的理论依据.结果表明,砷在水稻中的分布情况为根表>根部>秸秆>糙米;供试的糙米中砷含量为0.18~0.47 mg·kg,均符合国家卫生标准(GB 4810-1994).水稻根表铁锰膜中砷含量随根表中铁、锰的增加而富集,相关分析表明,根表铁锰膜形成可

  11. 栽培方式对粳型巨胚稻干物质积累和产量的影响%Effects of Cultivation Regimes on Dry Matter Accumulation and Grain Yield in Japonica Giant Embryo Rice

    张荣萍; 马均

    2011-01-01

    为了研究不同栽培方式对粳型巨胚稻各器官干物质积累动态及产量构成的影响,用粳型巨胚稻新品系'西巨胚1号'为试验对象,以常规粳稻'合系22-2'作对照.采用淹水、旱种和垄畦3种栽培方式进行种植.大田的移栽规格为(20+14)cm×14cm宽窄行双行种植,每穴种2苗,采用随机区组设计,3次重复.详细记载生育进程;于孕穗期、齐穗期和成熟期每个处理取4穴测定其叶面积和干物质重;成熟后,每处理取10穴考种测其产量性状,全小区收割计产.结果表明,3种栽培方式中,垄畦栽培下巨胚稻植株的分蘖增多,茎叶干物质积累较多,有利于构建早期高产群体;生育后期延长了叶片的寿命,提高了干物质运转率,有效穗和稳粒数显著增加,从而提高了稻谷产量.因此,在巨胚稻生产中建议采用垄畦栽培以提高物质积累和运转和获得最大产量.%For the purpose of studying the effects of different cultivation regimes on dynamics of dry matter accumulation in organs and grain yield components of ‘Japonica Xi-giant embryo-1', the experiment studied the three different cultivation regimes of submerged irrigation, dry cultivation and ridge cultivation used ‘Japonica Xi-giant embryo-1' as experimental materials, conventional japonica rice ‘Hexi-22-2' as control. The transplanting size was (20+ 14) cm × 14 cm the seedling number two plants per hill. This experiment with randomized block design and three repeated. The results indicated that, under the ridge cultivation, the tillering and the dry matter accumulation of stems and leaves were increased, and it was beneficial to build the high-yielding population in early stage. The effective panicles number and grain number per spike were increased for delaying the senescence of leaf during late growth stage and promoting the transportation percentage of dry matter accumulation under the ridge cultivation. Finally, the grain yield was increased

  12. Cytokinin delays dark-induced senescence in rice by maintaining the chlorophyll cycle and photosynthetic complexes.

    Talla, Sai Krishna; Panigrahy, Madhusmita; Kappara, Saivishnupriya; Nirosha, P; Neelamraju, Sarla; Ramanan, Rajeshwari

    2016-04-01

    The phytohormone cytokinin (CK) is known to delay senescence in plants. We studied the effect of a CK analog, 6-benzyl adenine (BA), on rice leaves to understand the possible mechanism by which CK delays senescence in a drought- and heat-tolerant rice cultivar Nagina22 (N22) using dark-induced senescence (DIS) as a surrogate for natural senescence of leaves. Leaves of N22-H-dgl162, a stay-green mutant of N22, and BA-treated N22 showed retention of chlorophyll (Chl) pigments, maintenance of the Chl a/b ratio, and delay in reduction of both photochemical efficiency and rate of oxygen evolution during DIS. HPLC analysis showed accumulation of 7-hydroxymethyl chlorophyll (HmChl) during DIS, and the kinetics of its accumulation correlated with progression of senescence. Transcriptome analysis revealed that several plastid-localized genes, specifically those associated with photosystem II (PSII), showed higher transcript levels in BA-treated N22 and the stay-green mutant leaves compared with naturally senescing N22 leaves. Real-time PCR analyses showed that genes coding for enzymes associated with Chl a/b interconversion and proteins associated with light-harvesting complexes maintained higher transcript levels up to 72h of DIS following BA treatment. The pigment-protein complexes analyzed by green gel remained intact in both N22-H-dgl162 and BA-treated N22 leaves even after 96h of DIS. Thus, CK delays senescence by accumulation of HmChl and up-regulating genes in the Chl cycle, thereby maintaining the Chl a/b ratio. Also, CK treatment retains higher transcript levels of PSII-related genes, resulting in the stability of photosynthetic pigment complexes and functional stay-greenness in rice. PMID:26826216

  13. Genetic enhancement of specialty rice through mutation approach - short grain aromatic rice

    India has a rich diversity of widely distributed aromatic rices. They include Basmati, whose cultivation is limited to a marked out geographic zone while the short grain aromatic rices are grown in localized pockets throughout India and with their unique sensory and cooking traits, cater defined groups of consumers in specific niche markets. Some short grain aromatic rices like Dubraj, Durgabhog, Makarkanda, Badshabhog are superior to Basmati in traits like high kernel elongation, high volume expansion and high head rice recovery while Bindli, is superior to Basmati in aroma and grain elongation (∼200%). The well known Kalajeera is known for the retention of aroma even after long storage. Till date, little attention was paid to short grain aromatic rice improvement as all focus was directed towards improvement of Basmati. The less coverage under the short grain aromatic rices can be attributable to their low productivity, long duration and tall plant stature. As high economic returns are feasible with varieties with shorter duration and shorter height with high yield, mutation approach was attempted to induce erect, semi dwarf, non lodging mutants with high yield potential while keeping the unique grain type and cooking quality traits of the parent cultivar. Twelve popular cultivars from different states i.e. Kalanamak, Dubraj, Tulsiphool, Randhunipagal, Badshahbhog, Katrani, Improved Raskadam, Kalajeera, Pimpudibasa, Chinikamini, Dhusara and Kalajoha were subjected to gamma (γ) irradiation. From M2 generation, selection was initiated to isolate mutants with shorter duration and plant height. Mutants with shorter (∼20%) stature derived from Kalanamak, Dubraj, Kalajeera and Chinikamini showed high promise in the evaluation trials. Mutants with shortened duration (∼10d) were also isolated in all these four genotypes. With the isolation of mutants with desirable traits, expansion in area under the short grain aromatic rices is feasible and the expected rice

  14. Genetic Enhancement of Speciality Rice through Induced Mutation - Short-Grain Aromatic Rice

    India has a rich diversity of widely distributed aromatic rices. They include Basmati, whose cultivation is limited to a well-demarcated geographic zone, and the short grain aromatic rices that are grown in localized pockets throughout India, which with their unique sensory and cooking traits, cater to defined groups of consumers in specific niche markets. Some short-grain aromatic rices like Dubraj, Durgabhog, Makarkanda, Badshabhog are superior to Basmati in traits like high kernel elongation, high volume expansion and high head rice recovery, while Bindli is superior to Basmati in aroma and grain elongation. Kalajeera is known for the retention of aroma even after long storage. To date, little attention has been paid to short-grain aromatic rice, as the focus was directed towards improvement of Basmati. Less attention to the short-grain aromatic rices can be attributed to their low productivity, long duration and tall plant stature. As high economic returns are feasible with high-yielding varieties with shorter duration and shorter height, a mutagenesis approach was attempted to induce erect, semi dwarf, non-lodging mutants with high yield potential, while keeping the unique grain type and cooking quality traits of the parent cultivar. Twelve popular cultivars from different states (Kalanamak, Dubraj, Tulsiphool, Randhunipagal, Badshahbhog, Katrani, Improved Raskadam, Kalajeera, Pimpudibasa, Chinikamini, Dhusara and Kalajoha) were subjected to gamma (γ) irradiation. From the M2 generation, selection was initiated to isolate mutants with shorter duration and plant height. Mutants with shorter (∼20%) stature derived from Kalanamak, Dubraj, Kalajeera and Chinikamini showed high promise in the evaluation trials. Mutants with shortened duration (∼10d) were also isolated in all the four genotypes. With the isolation of mutants with desirable traits, an expansion in the area under short grain aromatic rices is feasible, and the expected rice surplus can augment

  15. Regulation of Mutant p53 Protein Expression

    Vijayakumaran, Reshma; Tan, Kah Hin; Miranda, Panimaya Jeffreena; Haupt, Sue; Haupt, Ygal

    2015-01-01

    For several decades, p53 has been detected in cancer biopsies by virtue of its high protein expression level which is considered indicative of mutation. Surprisingly, however, mouse genetic studies revealed that mutant p53 is inherently labile, similar to its wild type (wt) counterpart. Consistently, in response to stress conditions, both wt and mutant p53 accumulate in cells. While wt p53 returns to basal level following recovery from stress, mutant p53 remains stable. In part, this can be e...

  16. Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

    2007-01-01

    The interplanting with zero-tillage of rice, i.e. directsowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting), ZI (Zero-tillage, no straw manure and rice interplanting), PTS (Plowing tillage, straw manure and rice transplanting), and PT (Plowing tillage, no straw manure and rice transplanting), were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002), there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003). Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in

  17. 砷-铅交互作用对水稻根表铁膜富集及根系吸收砷铅的影响%Effects of arsenic and lead interaction on arsenic and lead accumulation in iron plaque and uptake by rice roots

    胡莹; 段桂兰; 刘云霞; 黄益宗

    2012-01-01

    Iron plaque on the surface of rice roots formed naturally by soil-quartz sand culture. Interactive effects between As and Pb on As and Pb uptake by rice roots and accumulation in iron plaque were investigated. The results showed that As and Pb accumulations in iron plaque were significantly affected by As and Pb addition, and the interaction between As and Pb had significant effects on the uptake of these two elements by rice roots and As accumulation in iron plaque. Pb addition enhanced the As uptake by rice roots. When rice plants were treated with 25 μmol.L-1 As, 25μmol.L-1 Pb addition increased As uptake by 53.3% compared with Pb control treatment. Similarly, As addition also enhanced Pb uptake by rice roots. When rice plants were treated with 25 and 50 μmol.L-1 Pb, 50 μmol.L-1 As addition increased Pb uptake by 20.2% and 28.6% respectively compared with As control treatment. As also enhanced the translocation of Pb from iron plaque to roots, but the translocation of As from iron plaque to roots was not affected significantly by Pb. This study implies that the complex interactions among heavy metal might exist under co-contaminated conditions, and the interaction could affect the heavy metal uptake by rice roots and their accumulation in iron plaque.%采用土-砂联合培养方法诱导水稻根表自然形成铁氧化物膜,研究了As.Pb交互作用对水稻根表铁膜吸附砷铅及根系吸收As和Pb的影响.结果表明,As和Pb的添加显著地影响水稻根表铁膜对As和Pb的吸附,并且As-Pb交互作用显著地影响水稻根系对两元素的吸收及根表铁膜对As的吸附.添加Pb可促进水稻根系对As的吸收.当As浓度为25μmol·L-1时,浓度为25μmol·L-1Pb处理与对照相比导致水稻根系吸收As提高了53.3%.同样,施用As也可以促进水稻根系对Pb的吸收,当Pb的浓度为25μmol·L-1和50μmol.L-1时,50μmol·L-1As处理与对照相比,水稻根系吸收Pb分别提高20.2

  18. Connexin mutants and cataracts

    EricCBeyer

    2013-04-01

    Full Text Available The lens is a multicellular, but avascular tissue that must stay transparent to allow normal transmission of light and focusing of it on the retina. Damage to lens cells and/or proteins can cause cataracts, opacities that disrupt these processes. The normal survival of the lens is facilitated by an extensive network of gap junctions formed predominantly of connexin46 and connexin50. Mutations of the genes that encode these connexins (GJA3 and GJA8 have been identified and linked to inheritance of cataracts in human families and mouse lines. In vitro expression studies of several of these mutants have shown that they exhibit abnormalities that may lead to disease. Many of the mutants reduce or modify intercellular communication due to channel alterations (including loss of function or altered gating or due to impaired cellular trafficking which reduces the number of gap junction channels within the plasma membrane. However, the abnormalities detected in studies of other mutants suggest that they cause cataracts through other mechanisms including gain of hemichannel function (leading to cell injury and death and formation of cytoplasmic accumulations (that may act as light scattering particles. These observations and the anticipated results of ongoing studies should elucidate the mechanisms of cataract development due to mutations of lens connexins and abnormalities of other lens proteins. They may also contribute to our understanding of the mechanisms of disease due to connexin mutations in other tissues.

  19. Miracle Rice

    2009-01-01

    A pioneering agricultural scientist helps China find its way out of a food deficit BIG YIELDS: Despite the remarkable accomplishments he has already achieved, Yuan Longping is still working hard to improve the hybrid rice strain he has developed

  20. Variations among rice cultivars on root oxidation and Cd uptake

    LIU Jian-guo; WANG De-ke; XU Jia-kuan; ZHU Qing-sen; WONG Ming-hung

    2006-01-01

    In order to understand the mechanisms on the variation between rice cultivars in Cd uptake and accumulation, two pot soil experiments were conducted with typical rice cultivars that varied greatly in soil Cd uptake. The experiments with six rice cultivars showed that the root oxidation abilities of rice differed with rice cultivars and also with types of the cultivars, the cultivars with indica consanguinity were significantly higher than the cultivars with japonica consanguinity. Root oxidation abilities of the rice cultivars correlated positively and significantly (P<0.01) with their Cd concentrations and Cd quantity accumulations in rice plants. The experiments with two rice cultivars showed that significant differences also existed between the two cultivars in pot soil redox potentials, which of Shan you 63 (higher soil Cd accumulator) were significantly higher than that of Wu yun jing 7 (lower soil Cd accumulator) under different soil Cd levels, but the degrees of the differences varied with soil Cd levels. The differences were larger under soil Cd treatments than the control. The results indicate that root oxidation ability, especially in Cd contaminated soil, is one of the main mechanisms which dominate Cd uptake and accumulation by rice plant.

  1. Production and characterisation of amorphous silica from rice husk waste

    Madrid, Rosario; Nogueira, C. A.; Margarido, F.

    2012-01-01

    Rice covers about 1% of the earth’s surface. Rice husk is the major by-product of the riceprocessing industries which must be appropriately managed. On average 20% of the rice paddy is husk. The major constituents of rice husk are cellulose, lignin and silica. During growth, rice plants absorb silica and other minerals from the soil and accumulate it into their structures. Its composition varies with the diversity, climate and geographic location of growth. The high grade of silica in the hus...

  2. OsDMI3 Is a Novel Component of Abscisic Acid Signaling in the Induction of Antioxidant Defense in Leaves of Rice

    Ben Shi; Lan Ni; Aying Zhang; Jianmei Cao; Hong Zhang; Tingting Qin; Mingpu Tan; Jianhua Zhang; Mingyi Jiang

    2012-01-01

    Ca2+ and calmodulin (CaM) have been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense.However,it is unknown whether Ca2+/CaM-dependent protein kinase (CCaMK) is involved in the process.In the present study,the role of rice CCaMK,OsDMI3,in ABA-induced antioxidant defense was investigated in leaves of rice (Oryza sativa) plants.Treatments with ABA,H2O2,and polyethylene glycol (PEG) induced the expression of OsDMI3 and the activity of OsDMI3,and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress.Subcellular localization analysis showed that OsDMI3 is located in the nucleus,the cytoplasm,and the plasma membrane.The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference (RNAi) silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase (SOD) and catalase (CAT).Further,the oxidative damage induced by higher concentrations of PEG and H2O2 was aggravated in the mutant of OsDMI3.Moreover,the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling,but the initial H2O2 production induced by ABA is not dependent on the activation of OsDMI3 in leaves of rice plants.Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.

  3. Rice breeding with induced mutations in France

    Mutation experiments with rice at Montpellier yielded strains with improved lodging resistance, grain size, maturing time, milling quality and other characters. The general performance of these mutant strains was tested in field trials. Further mutagenic treatments were made to improve the high-yielding short grain varieties with regard to grain quality and seed dormancy. (author)

  4. Proteome Analysis of Rice Root Proteins Regulated by Gibberellin

    Setsuko Komatsu; Hirosato Konishi

    2005-01-01

    To gain an enhanced understanding of the mechanism by which gibberellins (GAs) regulate the growth and development of plants, it is necessary to identify proteins regulated by GA. Proteome analysis techniques have been applied as a direct,effective, and reliable tool in differential protein expressions. In previous studies,sixteen proteins showed differences in accumulation levels as a result of treatment with GA3, uniconazole, or abscisic acid (ABA), and/or the differences between the GA-deficient semi-dwarf mutant, Tan-ginbozu, and normal cultivars. Among these proteins, aldolase increased in roots treated with GA3, was present at low levels in Tan-ginbozu roots, and decreased in roots treated with uniconazole or ABA. In a root elongation assay, the growth of aldolase-antisense transgenic rice was half of that of vector control transgenic rice. These results indicate that increases in aldolase activity stimulate the glycolytic pathway and may play an important role in the GA-induced growth of roots. In this review, we discuss the relationship among GA, aldolase, and root growth.

  5. Investigation of intercellular salicylic acid accumulation during compatible and incompatible Arabidopsis-pseudomonas syringae interactions using a fast neutron-generated mutant allele of EDS5 identified by genetic mapping and whole-genome sequencing.

    Jessie L Carviel

    Full Text Available A whole-genome sequencing technique developed to identify fast neutron-induced deletion mutations revealed that iap1-1 is a new allele of EDS5 (eds5-5. RPS2-AvrRpt2-initiated effector-triggered immunity (ETI was compromised in iap1-1/eds5-5 with respect to in planta bacterial levels and the hypersensitive response, while intra- and intercellular free salicylic acid (SA accumulation was greatly reduced, suggesting that SA contributes as both an intracellular signaling molecule and an antimicrobial agent in the intercellular space during ETI. During the compatible interaction between wild-type Col-0 and virulent Pseudomonas syringae pv. tomato (Pst, little intercellular free SA accumulated, which led to the hypothesis that Pst suppresses intercellular SA accumulation. When Col-0 was inoculated with a coronatine-deficient strain of Pst, high levels of intercellular SA accumulation were observed, suggesting that Pst suppresses intercellular SA accumulation using its phytotoxin coronatine. This work suggests that accumulation of SA in the intercellular space is an important component of basal/PAMP-triggered immunity as well as ETI to pathogens that colonize the intercellular space.

  6. Induced mutations to develop sources of resistance to rice blast, Pyricularia grisea Sacc

    Rice blast caused by Pyricularia grisea is the most important disease limiting yields worldwide. The pathogen has many virulent forms or pathotypes, hence durable blast resistance is lacking. Studies on strategy to develop durable blast resistance based on defining the genetic structure of the population, using DNA-fingerprinting, and virulence diversity are described. This strategy is leading to the identification of resistance genes/sources against all isolates within a genetic family of the pathogen. Combinations of genes showing complementary resistance to different genetic families of the fungus exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. Identifying and combining resistance genes to which combinations of corresponding virulence genes are absent in the pathogen population should confer more durable resistance than that previously obtained. The use of induced mutations in the development of resistance was limited, since in most cases single gene changes were responsible for the induced resistance against all the pathogen population. The main objective here is to develop many mutants, each with a gene resistant to just one or a few families of the blast pathogen; and crossing them can accumulate the different resistance genes. A total of 201 Latin American commercial cultivars, including Cuban, Brazilian and Venezuelan were analyzed with different genetic families of the blast pathogen to identify potential sources of resistance to blast and identify complementary resistance sources. Characterization of the resistance of 37 mutants of the Colombian rice cultivar Oryzica 1 was conducted in collaboration with the INEA in Colombia. Results suggested that mutations for resistance to genetic families to which Oryzica 1 is susceptible were induced, although one

  7. Stamen specification and anther development in rice

    ZHANG DaBing; WILSON Zoe A

    2009-01-01

    Male reproductive development is a complex biological process which includes the formation of the stamen with differentiated anther tissues, in which microspores/pollens are generated, then anther dehiscence and subsequently pollination. Stamen specification and anther development involve a number of extraordinary events such as meristem transition, cell division and differentiation, cell to cell communication, etc., which need the cooperative interaction of sporophytic and gametophytic genes. The advent of various tools for rice functional gene identification, such as complete genome sequence, genome-wide microarrays, collections of mutants, has greatly facilitated our understanding of mechanisms of rice stamen specification and anther development. Male sterile lines are critical for hybrid rice breeding, therefore understanding these processes will not only contribute greatly to the basic knowledge of crop developmental biology, but also to the development of new varieties for hybrid rice breeding in the future.

  8. Protein disulfide isomerase-like protein 1-1 controls endosperm development through regulation of the amount and composition of seed proteins in rice.

    Yeon Jeong Kim

    Full Text Available Protein disulfide isomerase (PDI is a chaperone protein involved in oxidative protein folding by acting as a catalyst and assisting folding in the endoplasmic reticulum (ER. A genome database search showed that rice contains 19 PDI-like genes. However, their functions are not clearly identified. This paper shows possible functions of rice PDI-like protein 1-1 (PDIL1-1 during seed development. Seeds of the T-DNA insertion PDIL1-1 mutant, PDIL1-1Δ, identified by genomic DNA PCR and western blot analysis, display a chalky phenotype and a thick aleurone layer. Protein content per seed was significantly lower and free sugar content higher in PDIL1-1Δ mutant seeds than in the wild type. Proteomic analysis of PDIL1-1Δ mutant seeds showed that PDIL1-1 is post-translationally regulated, and its loss causes accumulation of many types of seed proteins including glucose/starch metabolism- and ROS (reactive oxygen species scavenging-related proteins. In addition, PDIL1-1 strongly interacts with the cysteine protease OsCP1. Our data indicate that the opaque phenotype of PDIL1-1Δ mutant seeds results from production of irregular starch granules and protein body through loss of regulatory activity for various proteins involved in the synthesis of seed components.

  9. Research progress in studying molecular physiological mechanisms of low Cd accumulation in rice grain%稻米Cd低积累分子生理机制的研究进展

    叶瑶瑶; 王飞娟; 俞娇; 石晓柳; 朱诚; 蔡冲

    2013-01-01

    随着我国国民经济持续快速增长,农田生态系统重金属污染日趋严重,Cd是环境中运移活跃、对生物和人类毒性较大的重金属元素.稻米是我国人民的主要食物来源,而水稻对Cd具有较强的吸收能力,因而稻米的安全性成为大家关注的问题.本文主要介绍了近几年来在水稻稻米低积累分子生理机制方面的研究进展.%With sustained rapid development of the national economy, heavy metal pollution of farmland ecosystem is becoming more serious. Cd is active transport in the environment, and has large toxicity to organism and human. Rice is the major source of food for Chinese, while rice has a strong absorption capacity of Cd,and thus rice security has become an issue of concern. This paper reviewed the research progress on molecular physiological mechanisms of low-Cd rice grain in recent years.

  10. Functional characterization of electron-transferring flavoprotein and its dehydrogenase required for fungal development and plant infection by the rice blast fungus.

    Li, Ya; Zhu, Jindong; Hu, Jiexiong; Meng, Xiuli; Zhang, Qi; Zhu, Kunpeng; Chen, Xiaomin; Chen, Xuehang; Li, Guangpu; Wang, Zonghua; Lu, Guodong

    2016-01-01

    Electron-transferring flavoprotein (ETF) and its dehydrogenase (ETFDH) are highly conserved electron carriers which mainly function in mitochondrial fatty acid β oxidation. Here, we report the identification and characterization of ETF α and β subunit encoding genes (ETFA and ETFB) and ETFDH encoding gene (ETFDH) in the rice blast fungus Magnaporthe oryzae. It was demonstrated that, by impacting fatty acid metabolism, ETF and ETFDH mutations led to severe growth and conidiation defects, which could be largely rescued by exogenous acetate or carbonate. Furthermore, although conidium germination and appressorium formation appeared to be normal in ETF and ETFDH mutants, most appressoria failed to penetrate the host epidermis due to low turgor pressure. The few appressoria that succeeded in penetration were severely restricted in invasive growth and consequently failed to cause disease. Moreover, ETF mutant etfb(-) induced ROS accumulation in infected host cells and exogenous antioxidant GSH accelerated mutant invading growth without increasing the penetration rate. In addition, mutant etfb(-) displayed elevated lipid body accumulation and reduced ATP synthesis. Taken together, ETF and ETFDH play an important role in fungal development and plant infection in M. oryzae by regulation of fatty acid metabolism, turgor establishment and induction of host ROS accumulation. PMID:27113712

  11. Iron biofortification of Myanmar rice

    May Sann Aung

    2013-05-01

    Full Text Available Iron (Fe deficiency causes elevates human mortality rates, especially in developing countries. In Myanmar, the prevalence of Fe-deficient anemia in children and pregnant women are 75% and 71%, respectively. Myanmar people have one of the highest per capita rice consumption rates globally. Consequently, production of Fe-biofortified rice would likely contribute to solving the Fe-deficiency problem in this human population. To produce Fe-biofortified Myanmar rice by transgenic methods, we first analyzed callus induction and regeneration efficiencies in 15 varieties that are presently popular because of their high yields and/or qualities. Callus formation and regeneration efficiency in each variety was strongly influenced by types of culture media containing a range of 2,4-dichlorophenoxyacetic acid concentrations. The Paw San Yin variety, which has a high Fe content in polished seeds, performed well in callus induction and regeneration trials. Thus, we transformed this variety using a gene expression cassette that enhanced Fe transport within rice plants through overexpression of the nicotianamine synthase gene HvNAS1, Fe flow to the endosperm through the Fe(II-nicotianamine transporter gene OsYSL2, and Fe accumulation in endosperm by the Fe storage protein gene SoyferH2. A line with a transgene insertion was successfully obtained. Enhanced expressions of the introduced genes OsYSL2, HvNAS1, and SoyferH2 occurred in immature T2 seeds. The transformants accumulated 3.4-fold higher Fe concentrations, and also 1.3-fold higher zinc concentrations in T2 polished seeds compared to levels in non-transgenic rice. This Fe-biofortified rice has the potential to reduce Fe-deficiency anemia in millions of Myanmar people without changing food habits and without introducing additional costs.

  12. Increasing upland rice variability through induced mutations

    Upland rice cultivars in Sao Paulo State, Brazil are generally tall (120-135 cm) even under low fertility soils (''cerrado''). In areas of continuous rice cultivation soil fertility is usually restored and the plants grow leafy, lodge, and seldom yield more than 2 t/ha. A mutation breeding programme involving Instituto Agronomico (IAC), International Atomic Energy Agency (IAEA), and Centro de Energia Nuclear na Agricultura (CENA) was started with the following objectives: (1) to induce a semidwarf mutant gene in the upland cultivar IAC 165; (2) once obtained, to incorporate the semidwarf gene in the standard hybridization program; and (3) to hybridize the new semidwarf source with the sd1 gene in order to identify useful nonallelic semidwarf genes primarily for upland conditions. Fifty-five thousand seeds were treated with 40 and 45 krad (400 and 450 Gy). Conventional methods of handling and selecting mutant plants were carried out at the Campinas Experimental Center. Sixty-three mutant lines were selected and classified. In 1989 eight and in 1990 ten promising mutant lines were included in preliminary yield trials under upland conditions. In both years IAC 165 yielded more than the selected mutants. Under sprinkler irrigation several mutants yielded as high as IAC 165. Some mutants were later than IAC 165. Preliminary results of crosses involving the eight selected mutants with BR-IRGA 409 indicate that the mutant genes are not allelic to sd1. Crosses of the mutants with IAC 165 indicate that the tall types are dominant. (author). 3 refs, 2 figs, 4 tabs

  13. Phytase activity in brown rice during steeping and sprouting

    Ou, Keqin; Cheng, Yongqiang; Xing, Ying; Lin, Li; Nout, Robert; Liang, Jianfen

    2010-01-01

    Phytase in brown rice will be activated and accumulated during seed germination. Changes of phytase activity in brown rice during two stages of germination (steeping and sprouting) affected by process conditions were studied. It was shown that steeping led to significant decrease of phytase activity (p 

  14. 连续2年UV-B辐射增强对传统水稻品种群体磷、钾累积及异质性特征的影响%Effects of Two-Year Concessional Enhance UV-B Radiation on P and K Accumulation and Heterogeneous Distribution of 2 Traditional Rice Varieties in Yuanyan Terraces

    祖艳群; 刘畅; 何永美; 李元

    2015-01-01

    UV-B radiation, which is one of environmental problem, has influenced ecosystem and human health. UV-B radiation has been paid more and more attention due to its influencing on material cycle. It is important to evaluate the responses of stable agricultural ecosystem to enhanced UV-B radiation, which located in area with high elevation and background UV-B. Field experiments were conducted to understand effects of two-year concessional UV-B radiation (0 and 5.0 kJ·m-2·d-1) on P and K accumulation and heterogeneous distribution of two traditional rice (Oryza sativa)varieties (BJLJ and YLG) in-situ Yuanyan terraces, Yunnan Province. The results showed that (1) Under two-year concessional enhanced UV-B radiation, biomass of leaves, stem, root and grain of two rice varieties decreased by 8.1%~61.3%; (2) Expect for P accumulation of stem of YLG, P contents and accumulation of leaves, stem, root, grain of two rice varieties increased with P accumulation of leaves and grain increased by 39.0%~46.2% and 39.1%~66.7%, respectively; (3) K accumulation of stem and root of two rice varieties increased. Except for total K accumulation of BJLJ in 2012, K accumulation increased by under enhanced UV-B radiation 5.0 kJ·m-2·d-1treatment. Therefore, P and K accumulation of traditional rice varieties increased with enhanced UV-B radiation. The responses of traditional rice varieties to enhance UV-B radiation are assumed on P accumulation in leaves, stem resistance and grain nutrients reserve.%UV-B辐射增强作为全球环境问题之一,UV-B辐射增强对全球物质循环产生的影响受到广泛的关注.为了评估持久稳定农田生态系统营养元素在高海拔和高 UV-B 辐射背景下对 UV-B 辐射的响应,在元阳梯田大田条件下,通过 2 年连续UV-B辐射处理(0和5.0 kJ·m-2·d-1),原位研究低纬度高海拔区稳定持续稻田生态系统中传统水稻(Oryza sativa)品种(月亮谷-YLG和白脚老粳-BJLJ)对P素和K素的群体累积特征及

  15. Analysis on Dry Matter Production Characteristics of Super Hybrid Rice

    2008-01-01

    Six middle-season indica hybrid rice combinations,including five super hybrid rice combinations with the high yield about 10.5 t/ha and a check hybrid rice combination Shanyou 63 with a yield potential about 9.5 t/ha,were used as materials to study the dry matter production characteristics.The super hybrid rice showed a high ability in dry matter production and accumulation and its yield enhanced with the increase of dry matter accumulation.The advantage period of dry matter production in the super hybrid rice was mainly at the middle and late growth stages compared with the check.The grain yield had no significant correlation with the dry matter accumulation before the elongation stage while had a significantly positive correlation with the dry matter accumulation from the elongation to maturity stages in super hybrid rice.There were more dry matter in vegetative organs at the heading stage in the super hybrid rice but its contribution to yield (apparent conversion percentage) was averagely 4.3 percent points lower than that in the check.For crop growth rate (CGR),the comparative advantage of super hybrid rice was at the middle and late stages,especially after flowering.Moreover,as the rising of leaf area index (LAI) and leaf area duration (LAD),CGR enhanced.The total LAD and the mean of LAD per day of super hybrid rice was about 14.79% and 10.31% higher than those of the check,respectively.The results indicate that the high yield of super hybrid rice mostly comes from the products of photosynthesis after heading,which is shown by the increased CGR at middle and later stages.It is suggested that LAD character might be used to better explain the advantage in the dry matter production of super hybrid rice than LAI.

  16. Co-pyrolysis of wastes mixtures obtained from rice production: upgrading of produced liquids

    Pinto, Filomena; Miranda, Miguel, imp.; Costa, Paula

    2015-01-01

    The increasing need to find alternative fuels to decrease the dependency on fossil fuels and to reduce the negative environmental impact of wastes accumulation has led to the idea of studying the energetic valorisation of different types of wastes by co-pyrolysis. Rice production process generates rice husk together with polyethylene (PE) bags that are used for rice packaging and to transport seeds and fertilizers used for rice culture. In Portugal, most of these plastic bags waste usually en...

  17. Speciation of trace metals and their uptake by rice in paddy soils

    Pan, Y.

    2015-01-01

    Rice (Oryza sativa L.) is the most important staple food in South and Southeast Asia and plays a crucial role in food security. However, with fast urbanization and industrialization and economic growth in these parts of the world, the production and quality of rice has become an increasing concern, because contamination of paddy soils with trace metals in industrialized areas can lead to yield reduction of rice, a decline in the nutritional quality of the rice, and an accumulation of trace me...

  18. Genome-wide association mapping identifies a new arsenate reductase enzyme critical for limiting arsenic accumulation in plants.

    Dai-Yin Chao

    2014-12-01

    Full Text Available Inorganic arsenic is a carcinogen, and its ingestion through foods such as rice presents a significant risk to human health. Plants chemically reduce arsenate to arsenite. Using genome-wide association (GWA mapping of loci controlling natural variation in arsenic accumulation in Arabidopsis thaliana allowed us to identify the arsenate reductase required for this reduction, which we named High Arsenic Content 1 (HAC1. Complementation verified the identity of HAC1, and expression in Escherichia coli lacking a functional arsenate reductase confirmed the arsenate reductase activity of HAC1. The HAC1 protein accumulates in the epidermis, the outer cell layer of the root, and also in the pericycle cells surrounding the central vascular tissue. Plants lacking HAC1 lose their ability to efflux arsenite from roots, leading to both increased transport of arsenic into the central vascular tissue and on into the shoot. HAC1 therefore functions to reduce arsenate to arsenite in the outer cell layer of the root, facilitating efflux of arsenic as arsenite back into the soil to limit both its accumulation in the root and transport to the shoot. Arsenate reduction by HAC1 in the pericycle may play a role in limiting arsenic loading into the xylem. Loss of HAC1-encoded arsenic reduction leads to a significant increase in arsenic accumulation in shoots, causing an increased sensitivity to arsenate toxicity. We also confirmed the previous observation that the ACR2 arsenate reductase in A. thaliana plays no detectable role in arsenic metabolism. Furthermore, ACR2 does not interact epistatically with HAC1, since arsenic metabolism in the acr2 hac1 double mutant is disrupted in an identical manner to that described for the hac1 single mutant. Our identification of HAC1 and its associated natural variation provides an important new resource for the development of low arsenic-containing food such as rice.

  19. Antimicrobial Activity of UV-Induced Phenylamides from Rice Leaves

    Hye Lin Park

    2014-11-01

    Full Text Available Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae. In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus. UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae, blight (Xanthomonas oryzae pv. oryzae and leaf streak (X. oryzae pv. oryzicola diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens.

  20. Antimicrobial activity of UV-induced phenylamides from rice leaves.

    Park, Hye Lin; Yoo, Youngchul; Hahn, Tae-Ryong; Bhoo, Seong Hee; Lee, Sang-Won; Cho, Man-Ho

    2014-01-01

    Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae). In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus). UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae), blight (Xanthomonas oryzae pv. oryzae) and leaf streak (X. oryzae pv. oryzicola) diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens. PMID:25383752

  1. Influence of ethyl-trinexapac on 1{sup 5N} accumulation and distribution and on highland rice yield; Influencia do etil-trinexapac no acumulo, na distribuicao de nitrogenio ({sup 15}N) e na massa de graos de arroz de terras altas

    Alvarez, Rita de Cassia Felix [Universidade Federal do Mato Grosso do Sul (UFMS), Chapadao do Sul, MS (Brazil)]. E-mail: ritaalvarez@nin.ufms.br; Crusciol, Carlos Alexandre Costa; Alvarez, Angela Cristina Camarim [UNESP, Botucatu, SP (Brazil). Faculdade de Ciencias Agronomicas. Depto. de Producao Vegetal]. E-mail: crusciol@fca.unesp.br; angela.alvarez@pop.com.br; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis]. E-mail: pcotrive@cena.usp.br; Rodrigues, Joao Domingos [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Botanica]. E-mail: mingo@unesp.br

    2007-11-15

    The high rice grain yields ensured by sprinkler irrigation have encouraged the use of higher fertilizer doses, mainly the nitrogen fertilizers. However, an improper management of nitrogen fertilization may result in plant lodging. Application of plant regulators may redirect assimilates to grain production while limiting the vegetative growth. This study aimed to: evaluate the influence of the growth regulator Ethyl-trinexapac on plant growth parameters and on {sup 15}N accumulation and distribution in the whole plant and plant components, and determine the contribution of nitrogen taken up in different developmental stages in panicle formation, yield components and rice yield. The experiment was carried out under controlled greenhouse conditions. The treatments consisted of application or not of a plant growth regulator (0 and 200 g active ingredient ha-1 of ethyl-trinexapac) at four plant development stages (beginning to end of tillering; end of tillering and flower differentiation; flower differentiation to flowering; flowering until physiological maturation). The experimental design was arranged in random blocks, in a 2 x 4 factorial scheme, with three replications. The plants were placed in a group of 48 pots. In a group of 24 pots with nutrient solution containing {sup 15}NH{sub 4}SO{sub 4}, plants were collected and separated in parts in the beginning of each pre-established plant development stage and at the end of each stage. In a second group (24 pots), pre-labeled plants were left to grow in nutrient solution with {sup 14}NH{sub 4}SO{sub 4} and harvested at the end of each cycle in order to access {sup 15}N redistribution.. The growth regulator reduced plant height and {sup 15}N accumulation in the panicle and promoted redistribution of the absorbed {sup 15}N, and increased accumulated {sup 15}N in root, stem+sheats and leaves. The contribution of absorbed {sup 15}N to panicle formation in each stage increased with the plant development, though in a

  2. Radiation breeding for high protein rice

    Rice is the main food of the people in Thailand as well as in most Asian countries. Most of the recommended rice varieties in Thailand are low in protein content. Protein deficiency is a serious problem of the people in the Northeastern region. Rice breeding for high protein should be practiced to solve this problem. Mutation breeding or the use of induced mutations in rice breeding has been studied for many years. Many successful results have been reported and presently 3 mutant varieties have been released. The parental RD 9 variety is recommended to the farmers due to its high yield resistance to brown plant hopper and moderated resistance to ragged stunt virus disease in the field conditions, even though protein content is moderately low (7 - 8% protein). In 1978, dry seeds of RD 9 were treated with 20 and 30 kilorads of gamma rays at the Office of Thai Atomic Energy for Peace. Higher protein content is the main objective of this mutation breeding. All of the treated seeds were planted in the field at Bangkhen Rice Experiment Station, and were analysed for protein content by the use of Dye Binding Capacity method at the Rice Division. Ninety-two samples of M2 seeds show higher protein content than the original variety RD 9 and they are in the range of 10 - 12 percent protein content. During the year 1979 - 1981, several high protein mutant lines of RD 9 variety were carried on in observation test at Khlong-Luang Rice Experiment Station Pathumthani province. The last wet season 1981, M5 plants were harvested and will be analysed for total protein and some essential amino acids

  3. A chloroplast-localized protein LESION AND LAMINA BENDING affects defence and growth responses in rice.

    Tamiru, Muluneh; Takagi, Hiroki; Abe, Akira; Yokota, Takao; Kanzaki, Hiroyuki; Okamoto, Haruko; Saitoh, Hiromasa; Takahashi, Hideyuki; Fujisaki, Koki; Oikawa, Kaori; Uemura, Aiko; Natsume, Satoshi; Jikumaru, Yusuke; Matsuura, Hideyuki; Umemura, Kenji; Terry, Matthew J; Terauchi, Ryohei

    2016-06-01

    Understanding how plants allocate their resources to growth or defence is of long-term importance to the development of new and improved varieties of different crops. Using molecular genetics, plant physiology, hormone analysis and Next-Generation Sequencing (NGS)-based transcript profiling, we have isolated and characterized the rice (Oryza sativa) LESION AND LAMINA BENDING (LLB) gene that encodes a chloroplast-targeted putative leucine carboxyl methyltransferase. Loss of LLB function results in reduced growth and yield, hypersensitive response (HR)-like lesions, accumulation of the antimicrobial compounds momilactones and phytocassanes, and constitutive expression of pathogenesis-related genes. Consistent with these defence-associated responses, llb shows enhanced resistance to rice blast (Magnaporthe oryzae) and bacterial blight (Xanthomonas oryzae pv. oryzae). The lesion and resistance phenotypes are likely to be caused by the over-accumulation of jasmonates (JAs) in the llb mutant including the JA precursor 12-oxo-phytodienoic acid. Additionally, llb shows an increased lamina inclination and enhanced early seedling growth due to elevated brassinosteroid (BR) synthesis and/or signalling. These findings show that LLB functions in the chloroplast to either directly or indirectly repress both JA- and BR-mediated responses, revealing a possible mechanism for controlling how plants allocate resources for defence and growth. PMID:26864209

  4. Construction of a rice glycosyltransferase phylogenomic database and identification of rice-diverged glycosyltransferases.

    Cao, Pei-Jian; Bartley, Laura E; Jung, Ki-Hong; Ronald, Pamela C

    2008-09-01

    Glycosyltransferases (GTs; EC 2.4.x.y) constitute a large group of enzymes that form glycosidic bonds through transfer of sugars from activated donor molecules to acceptor molecules. GTs are critical to the biosynthesis of plant cell walls, among other diverse functions. Based on the Carbohydrate-Active enZymes (CAZy) database and sequence similarity searches, we have identified 609 potential GT genes (loci) corresponding to 769 transcripts (gene models) in rice (Oryza sativa), the reference monocotyledonous species. Using domain composition and sequence similarity, these rice GTs were classified into 40 CAZy families plus an additional unknown class. We found that two Pfam domains of unknown function, PF04577 and PF04646, are associated with GT families GT61 and GT31, respectively. To facilitate functional analysis of this important and large gene family, we created a phylogenomic Rice GT Database (http://ricephylogenomics.ucdavis.edu/cellwalls/gt/). Through the database, several classes of functional genomic data, including mutant lines and gene expression data, can be displayed for each rice GT in the context of a phylogenetic tree, allowing for comparative analysis both within and between GT families. Comprehensive digital expression analysis of public gene expression data revealed that most ( approximately 80%) rice GTs are expressed. Based on analysis with Inparanoid, we identified 282 'rice-diverged' GTs that lack orthologs in sequenced dicots (Arabidopsis thaliana, Populus tricocarpa, Medicago truncatula, and Ricinus communis). Combining these analyses, we identified 33 rice-diverged GT genes (45 gene models) that are highly expressed in above-ground, vegetative tissues. From the literature and this analysis, 21 of these loci are excellent targets for functional examination toward understanding and manipulating grass cell wall qualities. Study of the remainder may reveal aspects of hormone and protein metabolism that are critical for rice biology. This list

  5. Genetic improvement of long grain aromatic rices through mutation approach

    In the export market, the price of basmati rice is two to three times higher than non-basmati rice. Traditional tall basmati variety Taroari Basmati, followed by Basmati 370 has supremacy over other basmati rice due to their exclusive quality. The breeding efforts of Basmati rices have resulted in the development of improved varieties, such as Pusa Basmati 1, which currently occupies a large area in the basmati zone. However, the variety has now become highly susceptible to blast, which is causing severe yield losses. The present investigation deals with the development of non-lodging, high yielding, long grain aromatic rices, employing a mutation approach of gamma rays (γ) irradiation. Mutant lines were developed from three elite basmati cultivars, i.e. Basmati 370, Pusa Basmati 1 and Pakistan Basmati. A mutant line derived from Basmati 370, CR 2007-1(IET 17276), is found to be highly promising in the basmati growing areas of Haryana and Punjab in the multi location trials. This promising mutant line consistently shows significant yield superiority over Pusa Basmati (5.36%) and Taroari Basmati (64.04%) and has all the desirable basmati grain quality traits that are closer to Taroari Basmati. It is also resistant to rice neck blast, moderately resistant to brown spot and also to biotype 1 of rice gall midge. The other mutants developed under the study have also shown higher yield potential than Pusa Basmatil 1, the highest yielding basmati cultivar that is being currently grown, but their quality characteristics could not reach the standard of Basmati rice. (author)

  6. Radiation induced promising mutants in Cowpea

    Cowpea (Vigna unguiculata L. Walp.) is an important legume crop of the tropics and subtropics of Asia, Africa and America. Breeding objectives in recent years have been to combine high yields with upright growth habit, bushy dwarf determinate plant type, early maturity and large seed size in addition to resistance to biotic and abiotic stresses. With a view to achieving these objectives and creating additional - variability, the seeds of an elite variety V-130 were irradiated with 200 Gy of gamma rays, and a number of morphological mutants were isolated. The mutants with desirable characters like erect growth habit, dwarf, large seed size, and high pod number were isolated in the M2 generation and studied further in subsequent generations for their yield potential and other characteristics. The dwarf plant mutant TCM 77-4, characterised by reduced plant height, bushy growth, large seed size and absence of tendril bred true when grown in rabi seasons, but behaved like parent in respect of growth habit in kharif season. It was far superior to the parent in respect of seed size in all the seasons. The mutant is envisaged to be the most suitable for rice fallows. Among the several promising mutants with large seed size, the mutant TCM 13-5 showed a test weight of 16.8 g against 8.8 g of the parent. A mutant with large pod number designated as TCM 121-8 showed promise with its very high yield, when grown in summer albeit with delayed maturity. Several mutants with maturity similar to that of the parent have shown higher seed yield. The variability generated through the radiation- induced mutation is being utilised for creating novel high yielding early maturing varieties of cowpea. (author)

  7. AFLP analysis of rice transformed with maize DNA by particle beam

    Many stable heritable rice lines were obtained via five years agricultural selection, which were derived from rice (oryza stative Japonica) Yujing-6 transgened with large fraction DNA of Zhengdan-14 (zea mays L.) by particle beam method. 18 pairs optimum selective primers were got by screening from 64 pairs AFLP selective primers via experiment on two mutant lines, which could amplify many DNA fingerprints and also could amplify polymorphic bands and target bands, both in this two mutant lines. Then the two mutant lines and two controls were analyzed with AFLP, the results showed that many polymorphic bands (such as novel bands, target bands, missing bands) were found in mutant lines. The discrepancy in DNA level indicated that rice, transgened with large fraction DNA of Zhengdan-14 by particle beam, might be inserted maize DNA and inherited steadily in some degree. It also indicated that it was possible to cultivate novel rice variety transformed with wide DNA by particle beam. (authors)

  8. Cambodia Rice Sector Review

    World Bank

    2015-01-01

    Cambodias rice exports are on a steep upward trajectory, benefiting from import duty preferences and new investments in rice mills and polishing factories. Cambodia’s major export competitors are Thailand and Vietnam. Thailand is a main competitor for fragrant rice, exporting itself ca 2.65 million tons of aromatic rice (including brokens) in 2010/2011. Vietnam is the principal competitor ...

  9. Alpha-picolinic acid,a fungal toxin and mammal apoptosis-inducing agent,elicits hypersensitive-like response and enhances disease resistance in rice

    Hai Kuo ZHANG; Xin ZHANG; Bi Zeng MAO; Qun LI; Zu Hua HE

    2004-01-01

    Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.

  10. Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

    Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

  11. Rice mutation breeding in Institute of Agricultural Genetics, Viet Nam

    Mutation breeding was initiated in 1960 in the northern part of Viet Nam. This technology had already been systematically applied till 1980 and was considered a successful method for rice improvement. Since 1990, more than 10 mutant rice varieties have been developed. In recent years, in vitro mutagenesis technique has been developed by irradiating mature embryos or callus during culture. Many mutant characteristics of economic importance, i.e., high grain yield, good grain quality, short growth duration and photoperiod insensitivity, tolerance to lodging and environmental stresses, and resistance to pests and diseases, have been incorporated into these mutant varieties. The introduction of photoperiod insensitivity in some varieties enabled farmers to grow two crops of rice per year and thus dramatically increased rice production. Mutant rice varieties have been planted on over 1.0 million hectares in provinces such as Hanoi, Bacgiang, Vinhphuc, Thaibinh, Hanam, Nghean, and Hatay of northern Viet Nam, and have already produced remarkable economic and social impacts, contributing to poverty alleviation in some provinces. (author)

  12. Trace Element Management in Rice

    Abin Sebastian

    2015-08-01

    Full Text Available Trace elements (TEs are vital for the operation of metabolic pathways that promote growth and structural integrity. Paddy soils are often prone to TE limitation due to intensive cultivation and irrigation practices. Apart from this, rice paddies are potentially contaminated with transition metals such as Cd, which are often referred to as toxic TEs. Deficiency of TEs in the soil not only delays plant growth but also causes exposure of plant roots to toxic TEs. Fine-tuning of nutrient cycling in the rice field is a practical solution to cope with TEs deficiency. Adjustment of soil physicochemical properties, biological process such as microbial activities, and fertilization helps to control TEs mobilization in soil. Modifications in root architecture, metal transporters activity, and physiological processes are also promising approaches to enhance TEs accumulation in grains. Through genetic manipulation, these modifications help to increase TE mining capacity of rice plants as well as transport and trafficking of TEs into the grains. The present review summarizes that regulation of TE mobilization in soil, and the genetic improvement of TE acquisition traits help to boost essential TE content in rice grain.

  13. Host active defense responses occur within 24 hours after pathogen inoculation in the rice blast system

    Phenotypic, cytological and molecular responses of rice to the fungus M. grisea were studied using rice cultivars and lesion mimic plants. Cultivar Katy was susceptible to several virulent Magnaporthe grisea isolates. A Sekiguchi-like lesion mimic mutant of Katy (LmmKaty) has shown enhanced resista...

  14. EFFECTS OF NITROGEN LEVELS ON DRY MATTER ACCUMULATION AND DISTRIBUTION IN RICE GENOTYPE WITH DIFFERENT NITROGEN USE EFFICIENCIES%氮素水平对不同氮效率基因型水稻的物质生产与分配的影响

    黄丽芬; 董芙蓉; 霍中洋; 全晓艳; 魏海燕; 戴其根; 许钶; 张洪程

    2012-01-01

    Under hydroponic group conditions, six typical rice genotypes were selected to investigate the characteristics of dry matter accumulation and distribution under three nitrogen levels of 5,15 and 25mg· kg^-1 Nitrogen use efficiency for dry matter (NUEdm) and nitrogen use efficiency for grain yield (NUEg) were obviously different between different rice genotypes under three N levels. And then, six different nitrogen efficiency genotypes can be classified into two types of nitrogen- efficient and nitrogen inefficient. NUEdm increased with the nitrogen levels. Whereas, NUEg firstly increased and then decreased with the increase of nitrogen. At the four critical stages, there are significant differences in dry matter accumulation between two NUE types of rice genotypes under different N levels. At maturing stage, the ratios of culm and sheath, root, panicle dry weight to entire plant dry matter accumulation were significantly affected by N levels. At the same level of nitrogen, the average ratios of culm and sheath, root and leaves dry weight to entire plant dry matter accumulation were higher in N- inefficient genotype than that in N-efficient genotype. On the contrary, the ratio of panicle dry weight to entire plant dry matter accumulation was higher in N-efficient genotype than that in N-inefficient genotype. Significant effects of nitrogen levels were observed on the rice yield between different NUE types. N-efficient rice yields were higher than nitrogen-inefficient at the same nitrogen level. What' s more, with the nitrogen level increasing, the difference of yield was more obviouser. Each organ proportion was relatively weak correlation with NUE. Correlation analysis also demonstrated that the dry matter accumulation at four critical stages of rice, the yield and the grain numbers per panicle were significantly correlated with the NUEg and NUEdm between different NUE types under different N levels.%研究了在群体水培条件下,3种氮素水平(5、15

  15. Deciphering Starch Quality of Rice Kernels Using Metabolite Profiling and Pedigree Network Analysis

    Miyako Kusano; Atsushi Fukushima; Naoko Fujita; Yozo Okazaki; Makoto Kobayashi; Naoko Fujita Oitome; Kaworu Ebana; Kazuki Saito

    2012-01-01

    The physiological properties of rice grains are immediately obvious to consumers.High-coverage metabolomic characterization of the rice diversity research set predicted a negative correlation between fatty acid and lipid levels and amylose/total starch ratio (amylose ratio),but the reason for this is unclear.To obtain new insight into the relationships among the visual phenotypes of rice kernels,starch granule structures,amylose ratios,and metabolite changes,we investigated the metabolite changes of five Japonica cultivars with various amylose ratios and two knockout mutants (e1,a Starch synthase Ⅲa (SSⅢa)-deficient mutant and the SSⅢa/starch branching enzyme (BE) double-knockout mutant 4019) by using mass spectrometry-based metabolomics techniques.Scanning electron microscopy clearly showed that the two mutants had unusual starch granule structures.The metabolomic compositions of two cultivars with high amylose ratios (Hoshiyutaka and Yumetoiro) exhibited similar patterns,while that of the double-knockout mutant,which has an extremely high amylose ratio,differed.Rice pedigree network analysis of the cultivars and the mutants provided insight into the association between metabolic-trait properties and their underlying genetic basis in rice breeding in Japan.Multidimensional scaling analysis revealed that the Hoshiyutaka and Yumetoiro cultivars were Indica-like,yet they are classified as Japonica subpopulations.Exploring metabolomic traits is a powerful way to follow rice genetic traces and breeding history.

  16. Natural and artificial mutants as valuable resources for functional genomics and molecular breeding

    Shu-Ye Jiang, Srinivasan Ramachandran

    2010-01-01

    Full Text Available With the completion of rice genome sequencing, large collection of expression data and the great efforts in annotating rice genomes, the next challenge is to systematically assign functions to all predicted genes in the genome. The generations and collections of mutants at the genome-wide level form technological platform of functional genomics. In this study, we have reviewed currently employed tools to generate such mutant populations. These tools include natural, physical, chemical, tissue culture, T-DNA, transposon or gene silencing based mutagenesis. We also reviewed how these tools were used to generate a large collection of mutants and how these mutants can be screened and detected for functional analysis of a gene. The data suggested that the current population of mutants might be large enough to tag all predicted genes. However, the collection of flanking sequencing tags (FSTs is limited due to the relatively higher cost. Thus, we have proposed a new strategy to generate gene-silencing mutants at the genome-wide level. Due to the large collection of insertion mutants, the next step to rice functional genomics should be focusing on functional characterization of tagged genes by detailed survey of corresponding mutants. Additionally, we also evaluated the utilization of these mutants as valuable resources for molecular breeding.

  17. Special rice in China

    2001-01-01

    Xianggu Rice: The rice originated from Jiangyong County, Hunan Province. Its characteristics were: even in grain shape, white in color, special fragrant in taste, and sticky in quality. Handongzao: It was from Wannian County, Jiangxi Province. The rice had big, fertile, and white grain, which was soft with fragrant smell, and it had high head rice rate. So, the local peasants liked to plant it. It was one of the "Tribute rice " in old time. Shizhu "Imperial Rice": The rice was also called "Fragrant Rice", was from Siyuan Village, Yuelai Town, Shizhu County, Sichuan Province. It was the treasure among the rices. The grain was bright in color. When it was cooked, the smell was fragrant. It was said that the rice was from "Han Dynasty", and has become the "Tribute Rice " since then. Blood Glutinous Rice: Originated from Changshu City, Jiangsu Province, the rice has been cultivated more than one hundred years. It had high nutrition value. Among the people, the Blood Glutinous Rice was often used as health food for lying-in women and patients. Qufu Fragrant Rice: Its characteristics were: clean, bright, and translucent in grain color, sticky in quality. It was suitable for cooking gruel and was also called "Fragrant Rice" in the local due to its strong fragrance. It was one of the "Tribute Rice" in old time. Taihu Lake Fragrant Japonica: The rice was from the Region of Taihu Lake, Jiangsu Province. The characteristics were: even and big in grain shape, soft in quality, white in color, fragrant in taste. The local people liked to plant and eat it.□ (To be continued) Translated by CHEN Wenhua, From "China Rice",No.1,1994

  18. Radiation effects on segregating seed in rice

    Seeds of segregating lines selected from dES treated M2 populations of rice were irradiated with gamma rays with a view to enhance the variabiity and thus selection parameter. Seedling and mature plant parameters and frequency of dividing cells showed reduction upon treatment. Very high frequency of chromosomal interchanges including rare cases of those involving the two nucleolar chromosomes and plants with 13 II were recorded. Several types of desirable morphological mutants were isolated. 7 refs., 3 tables. (author)

  19. Effects of Nitrogen Fertilization and Genotype on Rice Grain Macronutrients and Micronutrients

    LIN Zhao-miao; NING Hui-feng; BI Jun-guo; QIAO Jiang-fang; LIU Zheng-hui; LI Gang-hua; WANG Qiang-sheng; WANG Shao-hua; DING Yan-feng

    2014-01-01

    High nitrogen (N) input features China’s intensive rice production system. To elucidate N and genotype effects on accumulation of macronutrients and micronutrients in grains of japonica rice, and to discuss its significance in rice production, a three-year field experiment involving six japonica rice varieties and seven N treatments were performed. Macronutrients (Ca, Mg, K, and Na) and micronutrients (Cu, Fe, Mn, and Zn) concentrations in brown and milled rice were measured using an atomic absorption spectrophotometer. For macronutrients, no consistently significant effect of N was detected in both brown and milled rice. For micronutrients, N showed significant effect, especially in lowering Zn accumulation in brown and milled rice. In addition, N tended to increase Fe concentration in milled rice. Genotype showed larger effect on distribution of minerals in milled rice than N. The high-yielding variety, Wuyunjing 7, accumulated larger proportion of Mg, K, and Zn in the milled rice as compared with the other five varieties, and could be of value for rice breeding programs aiming at high nutritional quality. The results demonstrated differences in response to N between macronutrients and micronutrients, and are of significance for coping with‘hidden hunger’ both in humans and crops through agronomical practices.

  20. Zinc up-regulated the expression of the rice metallonthionein gene family and enhanced the zinc tolerance of yeast cells

    2007-01-01

    Northern blot and functional complementation assay were employed to analyze the effects of zinc on expression of ten rice metallothionein genes (OsMT-Is) in rice seedlings and the growth of yeast cells transformed with OsMT-Is. Northern blot revealed that in shoots of the rice seedlings treated with different Zn2+ concentrations, expression of most members of OsMT-I family was increased, except the type 4 OsMT-Is (OsMT-I-4a, 4b and 4c). In roots, Zn2+ significantly increased the transcription of OsMT-I-1b and OsMT-I-2c, but reduced the trascription of OsMT-I-1a and OsMT-I-3a. When these ten cDNAs were heterologously expressed in zinc sensitive yeast mutant, all transgenic yeasts showed increased tolerance to Zn2+, and zinc accumulation in these yeast cells also increased.These indicated that OsMT-I family members might respond to extra Zn2+, and they could enhance Zn2+ tolerance of cells by direct binding Zn2+.

  1. The heterotrimeric G protein α subunit acts upstream of the small GTPase Rac in disease resistance of rice

    Suharsono, Utut; Fujisawa, Yukiko; Kawasaki, Tsutomu; Iwasaki, Yukimoto; Satoh, Hikaru; Shimamoto, Ko

    2002-01-01

    We used rice dwarf1 (d1) mutants lacking a single-copy Gα gene and addressed Gα's role in disease resistance. d1 mutants exhibited a highly reduced hypersensitive response to infection by an avirulent race of rice blast. Activation of PR gene expression in the leaves of the mutants infected with rice blast was delayed for 24 h relative to the wild type. H2O2 production and PR gene expression induced by sphingolipid elicitors (SE) were strongly suppressed in d1 cell cultures. Expression of the...

  2. Human exposure to mercury in a compact fluorescent lamp manufacturing area: By food (rice and fish) consumption and occupational exposure

    To investigate human Hg exposure by food consumption and occupation exposure in a compact fluorescent lamp (CFL) manufacturing area, human hair and rice samples were collected from Gaohong town, Zhejiang Province, China. The mean values of total mercury (THg) and methylmercury (MeHg) concentrations in local cultivated rice samples were significantly higher than in commercial rice samples which indicated that CFL manufacturing activities resulted in Hg accumulation in local rice samples. For all of the study participants, significantly higher THg concentrations in human hair were observed in CFL workers compared with other residents. In comparison, MeHg concentrations in human hair of residents whose diet consisted of local cultivated rice were significantly higher than those who consumed commercial rice. These results demonstrated that CFL manufacturing activities resulted in THg accumulation in the hair of CFL workers. However, MeHg in hair were mainly affected by the sources of rice of the residents. - Highlights: • Rice samples were contaminated by Compact fluorescent lamp (CFL) manufacturing. • CFL manufacturing lead to THg accumulation in human hair. • MeHg in human hair were mainly affected by the sources of rice. • MeHg intake from fish consumption was lower than that from rice consumption. • PDI of MeHg by food consumption was below the guidelines for public health concern. - CFL manufacturing activities result in Hg accumulation in local rice samples and hair of CFL workers. However, MeHg in hair were mainly affected by sources of rice

  3. Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

    Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

    2002-01-01

    as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In...

  4. Iron-molybdenum cofactor synthesis in Azotobacter vinelandii Nif- mutants.

    Imperial, J; Shah, V K; Ugalde, R A; Ludden, P W; Brill, W J

    1987-01-01

    Nif- mutants of Azotobacter vinelandii defective in dinitrogenase activity synthesized iron-molybdenum cofactor (FeMo-co) and accumulated it in two protein-bound forms: inactive dinitrogenase and a possible intermediate involved in the FeMo-co biosynthetic pathway. FeMo-co from both these proteins could activate apo-dinitrogenase from FeMo-co-deficient mutants.

  5. The World of Rice

    VALERIE SARTOR

    2010-01-01

    @@ Pilafs, risottos, soups, snacks, paellas,stuffing, vinegars, wines and desserts-rice is used all over the world in myriad ways as food and drink.Although rice is one of the world's most ancient foods and it is impossible to know exactly where and when cultivation of this marvelous grain began, China is popularly acknowledged as the homeland of rice. Chinese people have many legends about rice. Some describe a benevolent goddess in silk robes whose gown accidentally picked up stray rice grains, which she dropped from the heavens to humans below. It's also said that Shennong, the Divine Farmer in Chinese myth, sowed the first rice on earth.

  6. Mutation breeding for irrigated rice at EMPASC, Santa Catarina, Brazil

    Mutation breeding for irrigated rice culture was initiated in 1985 at Estacao Experimental de Itajai (EMPASC), Santa Catarina in cooperation with Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, Sao Paulo. The traditional breeding programme conducted by EMPASC at Itajai is primarily based on the introduction of cultivars, pure lines, and hybridization. The new introductions have not been as good as the cultivars now grown by rice farmers. Rice breeders are constantly attempting to develop new cultivars for irrigated rice culture and seeking new methods to supplement the conventional breeding methods. The introduction of mutation techniques to the breeding programme at Itajai began with the irradiation of seeds of 4 rice cultivars with 12 and 24 kr (120 and 240 Gy) of gamma rays at CENA in 1985. The irradiated seeds were sown at Itajai in the same year. Seeds were harvested from 3 panicles of each plant. The mutant plants were then cultivated to develop select progenies. Mutants were visible only in the cultivars IRGA 408, EMPASC 105, and Pratao Precoce. Fifty-seven progeny were selected primarily from IRGA 408 and EMPASC 101 for the M4 generation. Progeny from Pratao Precoce were eliminated because they were not stable. Mutant progeny from EMPASC 101 were eliminated in the M5 generation because of a high incidence of chalk in the rice grains. The agronomic performance of IRGA 408 progeny was good and some mutant lines were further evaluated as follows: one in regional trials, 5 in advanced trials, and 5 in preliminary trials. Mutant line SCM-3-1-2 was evaluated in a regional trial and showed strong promise of becoming a new cultivar. (author). 3 refs, 4 tabs

  7. Effects and mechanism of UV-B radiation on rice growth

    The enhancement of UV-B radiation influences the growth of rice and physiology in different levels and this performances as changes in morphology destroyed photosynthetic system unstable anti-oxidation system changes of endogenous hormone content exacerbated rice diseases decreased biomass and developmental stage delay. Through the establishment of the response index we can evaluate the varietal differences in responses of the rice to UV-B radiation. Reasons for such varietal differences were differences in rice gene physiology and morphology developmental stage and environmental factors. The main mechanism in responses of the rice to UV-B radiation was induction of flavonoid compounds and accumulation of anthocyanins. Based on the analysis of the influence of enhanced UV-B radiation to rice and the varietal differences in responses to UV-B radiation and mechanism of rice the direction of the further research about the relationship between the rice and UV-B was put forward

  8. PAEs胁迫对高/低累积品种水稻根系形态及根系分泌低分子有机酸的影响%Effects of PAE Stress on Root Morphology andLow Molecular Weight Organic Acid (LMWOC) in Root Exudates of Rice (Oryza sativa L.) Cultivars with High- and Low-PAE Accumulation

    陈桐; 蔡全英; 吴启堂; 吕辉雄; 曾巧云; 李慧

    2015-01-01

    以前期筛选获得的邻苯二甲酸酯(PAEs)高/低累积基因型水稻(Oryza sativa L.)品种(培杂泰丰/丰优丝苗)进行水培试验,分别于分蘖期和拔节期采集样品,采用根系扫描仪分析根系形态学特性、高效液相色谱法测定根系分泌物中低分子有机酸成分,以及采用气相色谱-质谱仪(GC-MS)测定水稻根、茎、叶中 PAEs 质量分数。对比研究两种基因型水稻的根系形态特征和根系分泌物(低分子有机酸)的差异,初步探讨两种基因型水稻吸收累积PAEs差异原因,为保障农产品质量安全提供科学依据。结果表明,随着培养液中PAEs质量浓度增加,两种基因型水稻总根长、根表面积和根体积先增大后减小;相同PAEs质量浓度下,高累积型品种培杂泰丰根系形态指标大多高于丰优丝苗。两种水稻体内的PAEs质量分数均随污染物浓度增大而升高,高PAEs水平(80 mg·L-1)处理是低PAEs水平(20 mg·L-1)处理的3.8~7.3倍(邻苯二甲酸二丁酯(DBP))和2.7~20.4倍(邻苯二甲酸二(2-乙基己基)酯(DEHP)),培杂泰丰高于丰优丝苗。植物体内DBP和DEHP质量分数呈现根>叶≥茎。分蘖期两种水稻体内DBP和DEHP质量分数高于拔节期,且与营养液中PAEs的质量浓度呈显著相关,但拔节期的相关程度减弱。拔节期两种水稻根系分泌物中低分子有机酸质量浓度随培养液中PAEs质量浓度升高呈现不同的变化规律,但二者草酸质量浓度均增加(在1.11~8.13 mg·L-1之间),并与根系中DBP和DEHP的质量分数呈显著正相关。说明PAEs胁迫会影响水稻根系形态和低分子有机酸分泌,进而影响水稻对PAEs的吸收累积。%Two different genotypic cultivars of rice (Oryza sativa L.) with PAE (phthalic acid esters) high-accumulation (cultivar Peizataifeng) and low-accumulation (cultivar Fengyousimiao), were grown in hydroponic

  9. Biofortification of rice with lysine using endogenous histones.

    Wong, H W; Liu, Q; Sun, S S M

    2015-02-01

    Rice is the most consumed cereal grain in the world, but deficient in the essential amino acid lysine. Therefore, people in developing countries with limited food diversity who rely on rice as their major food source may suffer from malnutrition. Biofortification of stable crops by genetic engineering provides a fast and sustainable method to solve this problem. In this study, two endogenous rice lysine-rich histone proteins, RLRH1 and RLRH2, were over-expressed in rice seeds to achieve lysine biofortification. Their protein sequences passed an allergic sequence-based homology test. Their accumulations in rice seeds were raised to a moderate level by the use of a modified rice glutelin 1 promoter with lowered expression strength to avoid the occurrence of physiological abnormalities like unfolded protein response. The expressed proteins were further targeted to protein storage vacuoles for stable storage using a glutelin 1 signal peptide. The lysine content in the transgenic rice seeds was enhanced by up to 35 %, while other essential amino acids remained balanced, meeting the nutritional standards of the World Health Organization. No obvious unfolded protein response was detected. Different degrees of chalkiness, however, were detected in the transgenic seeds, and were positively correlated with both the levels of accumulated protein and lysine enhancement. This study offered a solution to the lysine deficiency in rice, while at the same time addressing concerns about food safety and physiological abnormalities in biofortified crops. PMID:25512028

  10. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    Zhouping Liu; Qiaofen Zhang; Tiqian Han; Yanfei Ding; Junwei Sun; Feijuan Wang; Cheng Zhu

    2015-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed ...

  11. Rice breeding for salinity tolerance through irradiated mutation in Thailand

    Rice seeds of 3 varieties (KDML105, RD15 and KTH17) had been irradiated by gamma ray and fast neutron with dosages of 200 and 300 grey. Then, M1 was transplanted in normal soil at Pathumthani Rice Research Center in 2004. M1 plants derived from 300 grey dosage of irradiation were mostly abnormal and died. A half of selected M2 population from 200 grey irradiation was transplanted in coastal saline soil at Petchaburi province in wet season of the year 2005. Most plants died and severe injured by salinity and water stress. 200 survived M3 plants were selected and later considered to be salt tolerant mutants. In 2006, selected M3 were tested for resistance to leaf blast in seedling stage. There were 5, 4 and 4 salt tolerant mutants of KDML105, RD15 and KTH17 that resistance to leaf blast. Those mutant seedlings were then transferred to be transplanted in concrete pond. Morphological and agronomic characters of these mutants were evaluated. We found 5 glutinous mutants from KTH17and 14 photoperiod insensitive mutants from RD15. Leaf samples of 14 RD15 mutants were taken to be characterized for salt tolerant gene using molecular markers B1.1-11 and RM140. Double haploid lines from all M3 mutants were generated. M4 seeds were harvested and retested for salinity tolerance in coastal saline soil and nutrient solution in 2007. (author)

  12. Physiological and biochemical parameters for evaluation and clustering of rice cultivars differing in salt tolerance at seedling stage

    Sumitahnun Chunthaburee; Anoma Dongsansuk; Jirawat Sanitchon; Wattana Pattanagul; Piyada Theerakulpisut

    2016-01-01

    Salinity tolerance levels and physiological changes were evaluated for twelve rice cultivars, including four white rice and eight black glutinous rice cultivars, during their seedling stage in response to salinity stress at 100 mM NaCl. All the rice cultivars evaluated showed an apparent decrease in growth characteristics and chlorophyll accumulation under salinity stress. By contrast an increase in proline, hydrogen peroxide, peroxidase (POX) activity and anthocyanins were observed for all c...

  13. Special rice in China

    2001-01-01

    @@Mingshui Rice: It originated from Zhangqiu County, Shandong Province. The characteristics of Mingshui Rice were: absorbing more water, swelling up greatly after being soaked, and being sticky and smelling fragrant after cooked.

  14. Screening of Toxin Mutant of Dickeya zeae and Its Biological Characters

    Jingyi ZHANG; Yutao WANG; Yanchang LI; Qiongguang LIU

    2013-01-01

    [Objective] This study aimed to screen toxin mutant of Dickeya zeae (Er-winia chrysanthemi pv. zeae) and investigate its biological characters. [Method] We obtained a toxin mutant strain D. zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain. [Result] There was no significant difference in pectin lyase, protease, cellulase and the production of extracellular polysaccharide and lipopolysaccharide, but significant difference in toxin biological activities and vir-ulence. Ech7-3-42 mutant did not produce toxin, as wel as the loss of virulence on rice and HR on tobacco, but did not lose the ability to soft rot on potato. Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk, but it could not cause rice foot rot. Dickeya zeae (wild and mutant strain) could be detected by PCR in the root neck and below the 1-2 cm long stem area, but could not be detected in the leaves. [Conclusion] We believed that toxin may be one of the important factors for D. zeae virulence on rice.

  15. Phenolic Phytoalexins in Rice: Biological Functions and Biosynthesis.

    Cho, Man-Ho; Lee, Sang-Won

    2015-01-01

    Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the only known phenolic phytoalexin in rice. However, recent studies have shown that phenylamides are involved in defense against pathogen attacks in rice. Phenylamides are amine-conjugated phenolic acids that are induced by pathogen infections and abiotic stresses including ultra violet (UV) radiation in rice. Stress-induced phenylamides, such as N-trans-cinnamoyltryptamine, N-p-coumaroylserotonin and N-cinnamoyltyramine, have been reported to possess antimicrobial activities against rice bacterial and fungal pathogens, an indication of their direct inhibitory roles against invading pathogens. This finding suggests that phenylamides act as phytoalexins in rice and belong to phenolic phytoalexins along with sakuranetin. Phenylamides also have been implicated in cell wall reinforcement for disease resistance and allelopathy of rice. Synthesis of phenolic phytoalexins is stimulated by phytopathogen attacks and abiotic challenges including UV radiation. Accumulating evidence has demonstrated that biosynthetic pathways including the shikimate, phenylpropanoid and arylmonoamine pathways are coordinately activated for phenolic phytoalexin synthesis, and related genes are induced by biotic and abiotic stresses in rice. PMID:26690131

  16. Sustainable enhancement of rice (Oryza sativa L.) production through the use of mutation breeding

    Four new high yield rice varieties with excellent quality were developed through mutagenesis at Nuclear Institute of Agriculture (NIA), Tando Jam, Pakistan, and released by the Provincial Seed Council, Government of Sindh for general cultivation. Both chemical and physical mutagenesis is proven to be useful in mutation induction. The first mutant rice variety 'Shadab', released in 1987, is a mutant of IR6 induced using ethyl methane sulphonate (EMS 0.5%); the 2nd variety 'Shua- 92', released in 1993, evolved from IR8 by irradiation of 15 Gy fast neutrons; the third variety Khushboo-95, released in 1996, was selected from gamma rays (200 Gy) treated progenies of Jajai-77 (aromatic). The most recent mutant variety 'Sarshar', released in 2001, was also developed from IR8 after treatment of 150 Gy gamma rays. These varieties have substantially increased the yield potential of rice production in Sindh and Balochistan provinces, and brought significant economic impact to rice farmers. (author)

  17. Mechanisms controlling arsenic uptake in rice grown in mining impacted regions in South China.

    Junhui Li

    Full Text Available Foods produced on soils impacted by Pb-Zn mining activities are a potential health risk due to plant uptake of the arsenic (As associated with such mining. A field survey was undertaken in two Pb-Zn mining-impacted paddy fields in Guangdong Province, China to assess As accumulation and translocation, as well as other factors influencing As in twelve commonly grown rice cultivars. The results showed that grain As concentrations in all the surveyed rice failed national food standards, irrespective of As speciation. Among the 12 rice cultivars, "SY-89" and "DY-162" had the least As in rice grain. No significant difference for As concentration in grain was observed between the rice grown in the two areas that differed significantly for soil As levels, suggesting that the amount of As contamination in the soil is not necessarily the overriding factor controlling the As content in the rice grain. The iron and manganese plaque on the root surface curtailed As accumulation in rice roots. Based on our results, the accumulation of As within rice plants was strongly associated with such soil properties such as silicon, phosphorus, organic matter, pH, and clay content. Understanding the factors and mechanisms controlling As uptake is important to develop mitigation measures that can reduce the amount of As accumulated in rice grains produced on contaminated soils.

  18. Breeding for quality rice through induced mutation

    Results of two experiments on induced mutations in rice by gamma radiation are reported. In the first experiment, F2 seeds from a cross between IR 8 and Basmati 370 were exposed to 30 and 35 k/Rads of gamma rays from a Co60 source. A number of dwarf mutants with good plant type and long slender grain were evaluated for the yield potential and quality characteristics in M4 generation, using Sona as check variety. Some of the hybrid mutants combine yield as well as good quality characteristics. In the second experiment, a locally adapted scented variety Tilakchandan, with good grain quality was treated with EMS. A number of economic dwarf mutants have been isolated in M2 generation. This offers promise for use in the hybridization programme. (author)

  19. Special rice in China

    2001-01-01

    Wushan Rice: It grew in hilly land around Wu Mountain in Wang City, Hunan Province. Its grain is bright and transparent, and the cooked rice is soft, sticky, fragrant, and sweet in taste. It was a "Tribute Rice" in old time. Indian Indica: Growing in Wuchang City, Hubei Province, it was also called" Red Flower Rice" . It was characterized by its thin pericarp and soft, sticky, and oily quality. Its taste was delicious. Fragrant Rice 1: It was from Xinxiang and Hui counties, Henan Province. Its characteristics were: long-round in grain shape, white in color, soft and sticky in quality, and agreeable to the taste. It was usually used as a gift in the local. Baiyutang Rice: It originated from Gaozhuang Village, Beijing suburban district. It had good quality due to the irrigation of the spring water. The rice had even grain shape, white color, hard enough quality to be cooked, fragrant and sweet taste. It was one of the "Tribute Rice" in old time. Tian′e Indica Rice: Xianning and Wuchang counties, Hubei Province were its growing area. It also called "Double Grain" because of its big grain. The hull was red, while the grain was white. When cooked, it needed more water than normal rice, and the rice was agreeable to the taste. Baiyan Rice: It originated from Jishou County, Hunan Province. The grain was even in shape, white in color, and sticky in quality. The rice was easy to be cooked and was fragrant and sweet in taste. It was also a " Tribute Rice" in old time. □ (To be continued) Translated by CHEN Wenhua, From "China Rice", No. 1, 1994

  20. Identifying root system genes using induced mutants in barley

    Root systems play an important role in plant growth and development. They absorb water and nutrients, anchor plant in the soil and affect plant tolerance to various abiotic stresses. Despite their importance, the progress in understanding the molecular processes underlying root development has been achieved only in Arabidopsis thaliana. It was accomplished through detailed analysis of root mutants with the use of advanced molecular, genomic and bioinformatic tools. Recently, similar studies performed with rice and maize root mutants have led to the identification of homologous and novel genes controlling root system formation in monocots. The collection of barley mutants with changes in root system development and morphology has been developed in our Department after mutagenic treatments of spring barley varieties with N-methyl N-nitosourea (MNU) and sodium azide. Among these mutants, the majority was characterized by seminal roots significantly shorter than roots of a parent variety throughout a whole vegetation period. Additionally, several mutants with root hairs impaired at different stages of development have been identified. These mutants have become the material of studies aimed at genetic and molecular dissection of seminal root and root hair formation in barley. The studies included the molecular mapping of genes responsible for mutant phenotype using DNA markers and root transcriptome analysis in the mutant/parent variety system. Using cDNA RDA approach, we have identified the HvEXPB1 gene encoding root specific beta expansin related to the root hair initiation in barley. We have also initiated the database search for barley sequences homologous to the known Arabodopsis, maize and rice genes. The identified homologous ESTs are now used for isolation of the complete coding sequences and gene function will be validated through identification of mutations related to the altered phenotype. This work was supported by the IAEA Research Contracts 12611 and 12849

  1. Metabolite Profiling of Diverse Rice Germplasm and Identification of Conserved Metabolic Markers of Rice Roots in Response to Long-Term Mild Salinity Stress

    Myung Hee Nam

    2015-09-01

    Full Text Available The sensitivity of rice to salt stress greatly depends on growth stages, organ types and cultivars. Especially, the roots of young rice seedlings are highly salt-sensitive organs that limit plant growth, even under mild soil salinity conditions. In an attempt to identify metabolic markers of rice roots responding to salt stress, metabolite profiling was performed by 1H-NMR spectroscopy in 38 rice genotypes that varied in biomass accumulation under long-term mild salinity condition. Multivariate statistical analysis showed separation of the control and salt-treated rice roots and rice genotypes with differential growth potential. By quantitative analyses of 1H-NMR data, five conserved salt-responsive metabolic markers of rice roots were identified. Sucrose, allantoin and glutamate accumulated by salt stress, whereas the levels of glutamine and alanine decreased. A positive correlation of metabolite changes with growth potential and salt tolerance of rice genotypes was observed for allantoin and glutamine. Adjustment of nitrogen metabolism in rice roots is likely to be closely related to maintain the growth potential and increase the stress tolerance of rice.

  2. Genome-wide functional analysis reveals that infection-associated fungal autophagy is necessary for rice blast disease

    Kershaw, Michael J.; Talbot, Nicholas J.

    2009-01-01

    To cause rice blast disease, the fungus Magnaporthe oryzae elaborates specialized infection structures called appressoria, which use enormous turgor to rupture the tough outer cuticle of a rice leaf. Here, we report the generation of a set of 22 isogenic M. oryzae mutants each differing by a single component of the predicted autophagic machinery of the fungus. Analysis of this set of targeted deletion mutants demonstrated that loss of any of the 16 genes necessary for nonselective macroautoph...

  3. UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens

    Dawei Zheng; Yi Wang; Yu Han; Jin-Rong Xu; Chenfang Wang

    2016-01-01

    Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening...

  4. Special rice in China

    2000-01-01

    @@Shanxi black rice It was originally from Yang County, Hanzhong Region.This rice was a world-famous rice variety developed in 140 BC. It had pitch-black surface with the protein and oil contents being 6.8% and 20% higher than that of common rice, respectively. It had 15 kinds of amino acids and many kinds of vitamins. It was praised as" Black pearl" and "The king of the world riee".DongnianThe other names for Dongnian were "Yellow rice" and "Oil rice". It was grown in E City and Huangmei County,Hubei Province. It was characterized by its long-slim shape, milky yellow in color, oily, solid, and sticky quality, fragrant smell, and easiness for digestion.Guizhou black pearl rice

  5. Ammonium assimilation in rice based on the occurrence of 15N and inhibition of glutamine synthetase activity

    Assimilation of ammonium (NH4) into free amino acids and total reduced nitrogen (N) was monitored in both roots and shoots of two-week old rice seedlings supplied with 5 mM 99% (15NH4)2SO4 in aerated hydroponic culture with or without a 2 h preincubation with 1 mM methionine sulfoximine (MSX) an inhibitor of glutamine synthetase (GS) activity. 15NH4 was not assimilated into amino acids when the GS/GOGAT (glutamate synthase) cycle was inhibited by MSX. Inhibition of glutamine synthetase (GS) activity in roots with MSX increased both the amount of NH4 and the abundance of 15N labeled NH4. In contrast, the amount of Gln and Glu, and their proportions as 15N, decreased in roots when GS activity was inhibited. This research confirms the importance of GS/GOGAT in NH4 assimilation in rice roots. 15N-labeled studies indicate that NH4 ions incorporated by roots of rice are transformed primarily into glutamine (Gin) and glutamic acid (Glu) before being converted to other amino acids through transamination. The formation of amino acids such as aspartic acid (Asp) and alanine (Ala) directly from free NH4 in roots also has been reported. Translocation of free NH4 to plant shoots, based on the concentration of free NH4 in xylem exudate, has been reported in tomato, although NH4 in shoots primarily originates from nitrate reduction in the shoot. Photorespiration also can contribute to the accumulation of NH4 in leaves. The GS/GOGAT cycle appears to be primarily responsible for the assimilation of exogenously supplied NH4 and NH4 derived from nitrate reduction in leaves, as well as NH4 derived from photorespiration. Genetic evidence cited to support this conclusion includes the lethal effect of photorespiratory conditions on plant mutants deficient in chloroplast-localized GS and GOGAT activities, and the rapid accumulation of free NH4 in GS-deficient mutants under photorespiratory conditions. The present study was initiated to quantify the in vivo amino acid synthesis in rice

  6. 两个亚种间杂交稻新组合干物质积累及分配研究%Study on Accumulation and Distribution of Dry Matter in Two Intersubspecific Hybrid Rice Combinations

    刘玉龙; 邓应德; 周飞捷; 邓晓娟; 肖层林

    2011-01-01

    The two intersubspecific hybrid combinations Peiai 64S/R292 and Y58S/R292 were studied on their accumulation and distribution of dry matter and it's correlation with grain yield by use super hybrid variety Fengyuanyou 299 as cheek. The results showed follow: there is no observably difference in the relately between the accumulating of dry mater weight and grain yield on prophase. The accumulating of dry mater weight in the full heading stage and the maturing stage were significantly positive with the spikelets per panicle (SPP), filled grains per panicle (FGPP) and grain yield. There were notable the correlation between the dry mater weight and LAI (leaf area index) in same stage.The results indicated that in later stage, leaf area index and dry matter accumulation rate for Peiai 64S/R292, Y58S/R292 were increased than Fengyuanyou 299 in the stage, while stem material output rate were below than Fengyuanyou 299.Therefore, based on ensuring the accumulation of dry matter in hter stage in intersubspecific hybrid flee, to improve the dry matter of conversion rote, and to improve "flow" unblocked degree is an important way to get high-yield in the intersubspecific hybrid combinations.%以籼粳亚种问杂交稻新组合"培矮64S/R292"、"Y58S/R292"为材料,并以籼籼交超级杂交稻"丰源优299"为对照,研究了干物质积累和分配规律及其与产量的相关性.结果表明:3个供试组合生育前期干物质积累量与稻谷产量相关性不显著,齐穗期和成熟期干物质积累量与每穗总粒数、每穗实粒数及产量显著正相关,干物质的积累量与同期叶面积指数显著相关."培矮64S/R292"、"Y58S/R292"生育后期叶面积指数和干物质积累速率显著大于"丰源优299",茎杆物质输出速率低于"丰源优299".因此,亚种间杂交组合在保证后期干物质积累量的前提下,提高干物质的转化率,改善"流"的畅通程度,是进一步提高亚种间杂交组合产量的重要途径.

  7. Induced mutation breeding for the improvement of rice in Malaysia

    The first application of nuclear technology in mutation breeding for the improvement of rice was undertaken by the Malaysian Institute for Nuclear Technology Research (MINT) in December, 1984 for a Coordinated Research Programme under RCA/IAEA/FAO entitled Semi Dwarf Mutants for Rice Improvement in Asia and Pacific. The main objective was to generate semi dwarf mutants in both native and improved cultivars for possible use as new released cultivars or as parents in cross breeding programmes. Within five years, 101 semi dwarf mutants which have the potential to be used as new cultivars or as parents in cross breeding were identified. Twenty nine of the semi dwarf mutants have grain yield between 6000-7300 kg/ha which were classified as potentially good yielding mutants. The parent, Manik yielded about 5700 kg/ha. Forty seven mutants have grain yield between 5000 6000 kg/ha and 25 mutants yielded in the range of 4300-5000 kg/ha. Twelve mutants are resistant to BPH (brown planthopper) but only one, mutant ML15 has grain yield (6300 kg / ha) better than the parent. One of the most striking effects of radiation (gamma ray) was the formation of glutinous rice (Manik 817) with both good yield and head recovery. It is also interesting to note that one of the mutants (MA 03) shows a drastic change in its characteristics and performs better than the parent and other mutant lines. This mutant was late popularly known as mutant Tongkat Ali because of its: outstanding agronomic features such as very erect panicle even after grain filling, very strong culm and resistance to lodging. Even though this mutant was not officially released, due to its unique characteristics and high yield, it has been planted commercially by several farmers especially in the northern parts of Malaysia. More collaborative research programmes using induced mutation breeding have been carried out between MINT, MADA and also MARDI with the aim of producing new potential varieties with high yield, disease

  8. Induced mutations in rice improvement - - a decade of progress

    The mutation breeding technique has been successfully exploited in bringing about desirable changes in crop plants especially during the last decade. Seven local cultivars and IR-8 were treated with gamma rays, ethylmethane sulphonate, diethyl sulphate, hydrazine, etc. In M2 several plant and grain type mutants were recovered and grown in subsequent generations. About 36 fine grain mutants recovered from IR-8 and 125 grain shape mutants from the local cultivars were screened for their grain quality. Some of the IR-8 fine grain mutants were transluscent with higher protein content and deeper distribution of protein in the endosperm. The mutants from the local cultivars ranged in protein content from 5.5 to 13.7%. Some of the mutants had better cookin.o. quality than their controls. A survey of the World rice germplasm by the International Rice Research Institute, Philippines has shown that except for K8 and Chang-chu-ai-11, all the other dwarfs were allelic to the Dee-Geo-Woo-Gen dwarfing gene. Induced dwarfs may therefore offer alternative sources for dwarfing genes. About 63 short statured mutants were recovered from the local cultivars and genetic studies with five of the morphologically distinct dwarfs from Tellakattera have indicated their non-allelism with Dee-Geo-Woo-Gen and also amongst themselves. These dwarfs may be utilised in breeding programmes aimed at developing new high yielding varieties to avoid the genetic vulnerability. (author)

  9. Study on induction and selection of mutants for blast disease (Piricula oryzae) resistance

    The rice seeds of varieties Zhejiang 66, R8617 which were blast disease susceptible were treated by 15, 25, 35 krad 60Co-γ rays, and the disease resistant rice plants were selected in M2 generation with natural induced inoculation. The disease resistant plants selected from M2 were inoculated artificialy. 30, 34, 36 of variant plants were selected in the M2 generation and their mutation rate were 0.016, 0.0190, 0.316 percent respectively. The resistance for most of mutants can be hereditary. The disease resistance mutants from same parents with same treatment showed different resistance

  10. Protein repair L-isoaspartyl methyltransferase 1 (PIMT1) in rice improves seed longevity by preserving embryo vigor and viability.

    Wei, Yidong; Xu, Huibin; Diao, Lirong; Zhu, Yongsheng; Xie, Hongguang; Cai, Qiuhua; Wu, Fangxi; Wang, Zonghua; Zhang, Jianfu; Xie, Huaan

    2015-11-01

    Damaged proteins containing abnormal isoaspartyl (isoAsp) accumulate as seeds age and the abnormality is thought to undermine seed vigor. Protein-L-isoaspartyl methyltransferase (PIMT) is involved in isoAsp-containing protein repair. Two PIMT genes from rice (Oryza sativa L.), designated as OsPIMT1 and OsPIMT2, were isolated and investigated for their roles. The results indicated that OsPIMT2 was mainly present in green tissues, but OsPIMT1 largely accumulated in embryos. Confocal visualization of the transient expression of OsPIMTs showed that OsPIMT2 was localized in the chloroplast and nucleus, whereas OsPIMT1 was predominately found in the cytosol. Artificial aging results highlighted the sensitivity of the seeds of OsPIMT1 mutant line when subjected to accelerated aging. Overexpression of OsPIMT1 in transgenic seeds reduced the accumulation of isoAsp-containing protein in embryos, and increased embryo viability. The germination percentage of transgenic seeds overexpressing OsPIMT1 increased 9-15% compared to the WT seeds after 21-day of artificial aging, whereas seeds from the OsPIMT1 RNAi lines overaccumulated isoAsp in embryos and experienced rapid loss of seed germinability. Taken together, these data strongly indicated that OsPIMT1-related seed longevity improvement is probably due to the repair of detrimental isoAsp-containing proteins that over accumulate in embryos when subjected to accelerated aging. PMID:26438231

  11. FLOURY ENDOSPERM7 encodes a regulator of starch synthesis and amyloplast development essential for peripheral endosperm development in rice.

    Zhang, Long; Ren, Yulong; Lu, Bingyue; Yang, Chunyan; Feng, Zhiming; Liu, Zhou; Chen, Jun; Ma, Weiwei; Wang, Ying; Yu, Xiaowen; Wang, Yunlong; Zhang, Wenwei; Wang, Yihua; Liu, Shijia; Wu, Fuqing; Zhang, Xin; Guo, Xiuping; Bao, Yiqun; Jiang, Ling; Wan, Jianmin

    2016-02-01

    In cereal crops, starch synthesis and storage depend mainly on a specialized class of plastids, termed amyloplasts. Despite the importance of starch, the molecular machinery regulating starch synthesis and amyloplast development remains largely unknown. Here, we report the characterization of the rice (Oryza sativa) floury endosperm7 (flo7) mutant, which develops a floury-white endosperm only in the periphery and not in the inner portion. Consistent with the phenotypic alternation in flo7 endosperm, the flo7 mutant had reduced amylose content and seriously disrupted amylopectin structure only in the peripheral endosperm. Notably, flo7 peripheral endosperm cells showed obvious defects in compound starch grain development. Map-based cloning of FLO7 revealed that it encodes a protein of unknown function. FLO7 harbors an N-terminal transit peptide capable of targeting functional FLO7 fused to green fluorescent protein to amyloplast stroma in developing endosperm cells, and a domain of unknown function 1338 (DUF1338) that is highly conserved in green plants. Furthermore, our combined β-glucuronidase activity and RNA in situ hybridization assays showed that the FLO7 gene was expressed ubiquitously but exhibited a specific expression in the endosperm periphery. Moreover, a set of in vivo experiments demonstrated that the missing 32 aa in the flo7 mutant protein are essential for the stable accumulation of FLO7 in the endosperm. Together, our findings identify FLO7 as a unique plant regulator required for starch synthesis and amyloplast development within the peripheral endosperm and provide new insights into the spatial regulation of endosperm development in rice. PMID:26608643

  12. Effect of Nitrogen Fertilization on Dry Matter Accumulation,Translocation and Yield of Fujian Early Hybrid Rice%施氮量对福建杂交早稻干物质积累转运及产量的影响

    邹文广; 范祖军; 许旭明; 饶鸣钿; 张受刚; 马彬林; 卓伟; 韦新宇; 杨旺兴; 杨腾帮

    2014-01-01

    对福建杂交早稻金优2155和T78优2155进行施氮量试验。结果显示,在较高土壤肥力条件下,金优2155和T78优2155在施氮150 kg · hm-2有利于提高2个品种的有效穗、产量、叶片干物质量、茎鞘干物质量、干物质转运量、干物质转运率、转运干物质对籽粒贡献率;金优2155的每穗粒数、穗长、株高、千粒重、穗干物质量、花后干物质累积量随施氮量增加呈先增后减的抛物线变化趋势,而T78优2155的结实率变化趋势与之相反;T78优2155的每穗粒数、穗长、株高随施氮量的增加而增加,而金优2155的结实率、干物质累积量和T78优2155的千粒重变化趋势与之相反;T78优2155的干物质累积量抽穗期和成熟期随施氮量增加表现出不同的变化趋势;抽穗期和成熟期干物质累积量与有效穗和产量关系密切。%Experiments were conducted to evaluate the effects of nitrogen fertilization on early hybrid rices ,Jinyou 2155 and T78 You 2155 ,in Fujian .The results indicated that ,with high soil fertility ,the nitrogen application rate of 150 kg · hm -2 could improve the usable panicles ,grain yield ,dry matters in leaves and stem-sheaths ,dry matter translocation and rate ,as well as the contribution rate of dry matter translocation to grain weight gains .The spikelets per panicle , panicle length , plant height , 1000-grain weight , spike dry matters , and dry matter accumulation after anthesis increased initially ,and followed by a decline as the nitrogen amount applied to Jinyou 2155 increased .The seed setting rate of T78 You 2155 decreased with the increased fertilization .The spikelets per panicle ,panicle length and plant height increased with increasing nitrogen applicationon T 78 You 2155. The dry matter accumulation in Jinyou 2155 and the 1000-grain weight of T78 You 2155 decreased with the increased fertilization .The dry matter accumulation at the heading and maturing stages on T 78

  13. Starch and Prolamin Level in Single and Double High-Lysine Barley Mutants

    Kreis, M.; Doll, Hans

    1980-01-01

    At maturity the high-lysine barley (Hordeum vulgare L.) Ris0 mutants 1508, 527 and 29 kernels contained about 20% less starch and twice as much free sugars as the parent varieties Bomi and Carlsberg II. An enhanched effect on starch reduction and free sugar accumulation was observed during kernel...... development when the single mutants 527 and 29 are combined with the mutant 1508. At maturity, kernels of the double mutants 527/1508 and 29/1508 contained, respectively, 68 and 43% less starch than Bomi. The double mutant 29/1508 kernel had a slightly lower prolamin content than mutant 1508 which is the most...... prolamin-deficient single mutant. In the double mutant 527/1508, however, an almost complete suppression of prolamin synthesis was observed during kernel development. The percentage of lysine in the seed proteins of the double mutants was about the same as in the most extreme single mutant 1508. Based on...

  14. Extraction of light filth from rice flours, extruded rice products, and rice paper: collaborative study.

    Dent, R G

    1982-09-01

    Two new methods were developed for the extraction of rodent hairs and insect fragments from rice products: one for rice flour and one for extruded rice products and rice paper. A 100 g sample of rice flour was extracted with mineral oil-40% isopropanol, followed by a water phase as needed for additional cycles. For extruded rice products and rice paper, a 225 g sample of each was initially extracted as above, followed by a single extraction with mineral oil-20% isopropanol. Both methods used an acid hydrolysis pretreatment followed by wet sieving and a percolator extraction. Average rodent hair recoveries were 77.8% for rice flour and 82.2% for extruded rice products and rice paper. Average insect fragment recoveries were 89.6% for rice flour and 91.9% for extruded rice products and rice paper. Both methods were adopted official first action. PMID:7130079

  15. Conserved Functions of Arabidopsis and Rice CC-Type Glutaredoxins in Flower Development and Pathogen Response

    Zhen Wang; Shuping Xing; Rainer P. Birkenbihl; Sabine Zachgo

    2009-01-01

    Glutaredoxins (GRXs) are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we iso-lated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxy1 floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Ara-bidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop-ment and pathogen defence.

  16. The improvement of cisantana rice variety through induced mutation

    The continuous improvement for rice through breeding is necessary to obtain new varieties with good quality and quantity. Cisantana variety hairy tips could be improved by mutation breeding. Seeds of Cisantana variety was irradiated by gamma rays (60Co) at doses of 0.10, 0.20 and 0.30 kGy respectively at the Center for Application of Isotope and Radiation (CAIR) - Batan, Pasar Jumat, Jakarta. There after the irradiated seeds were planted as M1 plants at the CAIR’S experiment field in the dry season of 2000. Selection was carried out at the M2 generation and stressed on early maturity and bald spike. This was done at the experiment field at Pusakanegara - Subang in the Wet season of 2001/2002. From this population 19 mutants having early maturity and bald spike lets were selected. Purification in the next generation obtained 10 mutants which were homogeneous and without segregation. From these 10 mutants two mutant lines Obs-1688/PsJ and Obs-1692/PsJ were further tested. These two mutant lines showed good productivity and adaptability when tested at several locations. The resistance test for brown plant hopper and bacterial leaf blight disease showed that these two mutant lines are resistant to biotype 1 and 2, and medium resistant to biotype 3 of brown plant hopper, and also resistant to strain 3 and medium resistant to strain IV of bacterial leaf blight disease. These two mutant lines have good rice quality and were gelatinous. The Obs-1688/PsJ and Obs-1692/PsJ mutant lines were released as new rice varieties by the Minister of Agriculture and officially address as Mira-1 at 2006 and Bestari at 2008, respectively. (author)

  17. Aplicabilidade das cinzas da casca de arroz Applicability of rice husk ash

    Edson Luiz Foletto; Ronaldo Hoffmann; Rejane Scopel Hoffmann; Utinguassú Lima Portugal Jr.; Sérgio Luiz Jahn

    2005-01-01

    Currently, the accumulation of rice husk is a serious environmental problem. The burning of rice husk generates a considerable volume of ash, that falls to the ground and gets into the air and the rivers, causing a disequilibrium in the ecosystem. This motived research into solutions that aim to exploit the husks for energy generation and the ashes for developing diverse technological products. This work presents the possibilities of using rice husks and their ashes after burning.

  18. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice--A field study over four rice seasons in Hunan, China.

    Chen, De; Guo, Hu; Li, Ruiyue; Li, Lianqing; Pan, Genxing; Chang, Andrew; Joseph, Stephen

    2016-01-15

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha(-1). Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35-91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69-80% and 72-80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. PMID:26490528

  19. Defective active silicon uptake affects some components of rice resistance to brown spot.

    Dallagnol, Leandro J; Rodrigues, Fabrício A; Mielli, Mateus V B; Ma, Jian F; Datnoff, Lawrence E

    2009-01-01

    Rice is known to accumulate high amounts of silicon (Si) in plant tissue, which helps to decrease the intensity of many economically important rice diseases. Among these diseases, brown spot, caused by the fungus Bipolaris oryzae, is one of the most devastating because it negatively affects yield and grain quality. This study aimed to evaluate the importance of active root Si uptake in rice for controlling brown spot development. Some components of host resistance were evaluated in a rice mutant, low silicon 1 (lsi1), defective in active Si uptake, and its wild-type counterpart (cv. Oochikara). Plants were inoculated with B. oryzae after growing for 35 days in a hydroponic culture amended with 0 or 2 mMol Si. The components of host resistance evaluated were incubation period (IP), relative infection efficiency (RIE), area under brown spot progress curve (AUBSPC), final lesion size (FLS), rate of lesion expansion (r), and area under lesion expansion progress curve (AULEPC). Si content from both Oochikara and lsi1 in the +Si treatment increased in leaf tissue by 219 and 178%, respectively, over the nonamended controls. Plants from Oochikara had 112% more Si in leaf tissue than plants from lsi1. The IP of brown spot from Oochikara increased approximately 6 h in the presence of Si and the RIE, AUBSPC, FLS, r, and AULEPC were significantly reduced by 65, 75, 33, 36, and 35%, respectively. In the presence of Si, the IP increased 3 h for lsi1 but the RIE, AUBSPC, FLS, r, and AULEPC were reduced by only 40, 50, 12, 21, and 12%, respectively. The correlation between Si leaf content and IP was significantly positive but Si content was negatively correlated with RIE, AUBSPC, FLS, r, and AULEPC. Single degree-of-freedom contrasts showed that Oochikara and lsi1 supplied with Si were significantly different from those not supplied with Si for all components of resistance evaluated. This result showed that a reduced Si content in tissues of plants from lsi1 dramatically affected

  20. Studies on induced resistance to blast in rice

    Eleven rice varieties were treated with 60Co gamma ray, laser and other mutagens. 154 mutants with different characters were developed. 154 mutants and their parents have been inoculated with blast (Piricularia oryzae) races. It was found that the mutants of disease-resistance could be produced. The disease-resistant mutants with various better cheracters were selected. The frequencies of mutation in disease-resistance are different with different parental varieties. After inoculation with 13 blast physiological races, the results showed that the spectrum of resistance of mutants, other characters were changed, when one character was changed. In order to get a veriety with higher yield and disease-resistance, it is important to take account of other economic charaters

  1. Arsenic species in raw and cooked rice: Implications for human health in rural Bengal

    This study compares the concentrations of total and different species of arsenic (As) in 29 pairs of raw and cooked rice samples collected from households in an area of West Bengal affected by endemic arsenicism. The aim is to investigate the effects of indigenous cooking practice of the rural villagers on As accumulation and speciation in cooked rice. It is found that inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). Cooking of rice with water low in As (< 10 μg L−1) significantly decreases the total and inorganic As content in cooked rice compared to raw rice. Arsenic concentration is mainly decreased during boiling of rice grains with excess water. Washing of rice grains with low As water has negligible effect on grain As concentration. The study suggests that rice cooking with low As water by the villagers is a beneficial risk reduction strategy. Despite reductions in As content in cooked rice because of cooking with low As water, the consumption of cooked rice represents a significant health threat (in terms of chronic As toxicity) to the study population. - Highlights: • Pairs of raw and cooked rice samples are collected from households. • Total and different species of As in raw and cooked rice samples are compared. • Cooking with As safe water reduces total and inorganic As contents in cooked rice. • Inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). • Risks of As exposure from cooked rice consumption exceed the safety standards

  2. Arsenic species in raw and cooked rice: Implications for human health in rural Bengal

    Halder, Dipti, E-mail: dipti@kth.se [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden); Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Biswas, Ashis [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden); Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Šlejkovec, Zdenka [Environmental Sciences Department, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Chatterjee, Debashis [Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Nriagu, Jerome [Department of Environmental Health Sciences, School of Public Health, University of Michigan, 109 Observatory Street, Ann Arbor, MI 48109-2029 (United States); Jacks, Gunnar; Bhattacharya, Prosun [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden)

    2014-11-01

    This study compares the concentrations of total and different species of arsenic (As) in 29 pairs of raw and cooked rice samples collected from households in an area of West Bengal affected by endemic arsenicism. The aim is to investigate the effects of indigenous cooking practice of the rural villagers on As accumulation and speciation in cooked rice. It is found that inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). Cooking of rice with water low in As (< 10 μg L{sup −1}) significantly decreases the total and inorganic As content in cooked rice compared to raw rice. Arsenic concentration is mainly decreased during boiling of rice grains with excess water. Washing of rice grains with low As water has negligible effect on grain As concentration. The study suggests that rice cooking with low As water by the villagers is a beneficial risk reduction strategy. Despite reductions in As content in cooked rice because of cooking with low As water, the consumption of cooked rice represents a significant health threat (in terms of chronic As toxicity) to the study population. - Highlights: • Pairs of raw and cooked rice samples are collected from households. • Total and different species of As in raw and cooked rice samples are compared. • Cooking with As safe water reduces total and inorganic As contents in cooked rice. • Inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). • Risks of As exposure from cooked rice consumption exceed the safety standards.

  3. Rice that Filipinos Grow and Eat

    de Leon, John C.

    2005-01-01

    This paper introduces rice to the reader and analyzes the changes it has gone through these past 100 years in the shaping hands of varietal improvement science. Here, the richness of the crop as a genetic material and resource is revealed. Landrace rice, pureline selection rice, crossbred rice, semidwarf rice, hybrid rice, new plant type rice, designer rice - from the traditional to modern to futuristic - rice becomes all of these while traversing time in the Philippines. There is rice for th...

  4. Use of induced mutations to adopt aromatic rice to low country conditions of Sri Lanka

    Two aromatic rice accessions, Au 27789 and IR Basmati were used in mutation breeding by subjecting 12000 seeds of each variety to γ-ray doses of 200 or 300 Gy from a 60Co source. Based on agronomic characteristics, 635 M2 plants were selected and grown as M3 progenies. Sixty plants were selected from non-irradiated parental varieties using the same criteria, and tested along with mutant plant progenies. Both doses of γ-rays were effective in creating genetic variability for agronomic characteristics, with high heritability values when M2 parent to M3 progeny regression based heritabilities were compared with selection in non-irradiated control varieties. Three mutant lines with compact plant type, erect and larger flag leaf, compact panicles and acceptable quality recording the highest yield were tested in five locations over four seasons using two recommended cultivars as controls. The mutant line 22/3 with a medium level of aroma recorded more than 2.5 t/ha, higher than the average yield of rice (1.5 -2 t/ha) in low-country wet zone. It has a compact panicle and narrow leaf angle allowing denser planting, which may help further increase the yield. The mutant lines maintained superior kernel length, linear elongation ratio and expansion index, all of which are important characteristics of aromatic long grain rice. High quality aromatic Basmati rice is almost triple the price of rice produced from standard varieties, making their cultivation more profitable. Such grades fetch approximately two times the price of average-grade rice in international markets. Investigation and implementation of agronomic practices that enable the optimisation of the yield and quality of new mutant lines will help to increase profitability of rice cultivation in the marginal areas. Their further improvement may be possible through hybridisation among mutants

  5. Rice trade liberalization and poverty

    Gulati, Ashok; Narayanan, Sudha

    2002-01-01

    Rice is the lifeline of almost 70% of the world's poor residing in Asia, where more than 90% of world rice production and consumption takes place. Rice trade liberalization therefore has tremendous implications for poverty. The world rice market is highly distorted, partly because of the high degree of intervention in rice markets across the world. While poor countries such as Thailand, Vietnam, and India tend to “disprotect” rice sectors, the rich countries of East Asia (Japan and Korea), Eu...

  6. Inducing cold tolerance in Malagasy rice varieties IR 58614, Malady and Rojofotsy through in vitro mutagenesis

    The use of induced mutagenesis to develop cold tolerant mutants from Malagasy rice varieties was investigated with the aim of developing rice mutants that could be planted during the cold seasons in the country. The strategy involved the induction of calli from mature rice embryos and exposing the calli to different doses of gamma rays. The efficacy of different media compositions were evaluated both for callus induction and for plantlet regeneration. Selections for cold tolerance were carried out by attempting to induce the irradiated calli to regenerate at 12 deg. C. The putative mutants were evaluated for agronomic performance under controlled environments and field conditions. Data are presented on the optimal media compositions for both callus induction and plant regeneration for both indica and japonica rice varieties. In all, 3 cold tolerant induced mutants with high yield and seed set were identified. The implications of the findings and suggestions for the integration of the mutants into Malagasy rice agriculture in order to achieve 2 crops per year are discussed. (author)

  7. Construction of a Rice Glvcosvltransferase Phylogenomic Data base and Identification of Rice-Diverged Glvcosvltransferases

    Pei-Jian Cao; Laura E.Bartley; Ki-Hong Jung; Pamela C.Ronald

    2008-01-01

    GlycosyItransferases(GTs;Ec 2.4.x.y)constitute a large group of enzymes that form glycosidic bonds through transfer of sugars from activated donor molecules to acceptor molecules.GTs are critical to the biosynthesis of plant cell walls,among other diverse functions.Based on the Carbohydrate-Active enZymes(CAZy)database and sequence similarity searches,we have identified 609 potentiaI GT genes(loci)corresponding to 769 transcripts(gene models)in rice (Oryza sativa),the reference monocotyledonous species.Using domain composition and sequence similarity,these rice GTs were classified into 40 CAZy families plus an additionaI unknown class.We found that two Pfam domains of unknown function,PF04577 and PF04646,are associated with GT families GT61 and GT31,respectively.To facilitate functional analysis of this important and large gene family,we created a phylogenomic Rice GT Database(http://ricephylogenomics.ucdavis.edu/cellwalls/gt/).Through the database.severaI classes of functionaI genomic data,including mutant lines and gene expression data,can be displayed for each rice GT in the context of a phylogenetic tree,allowing for comparative analysis both within and between GT families.Comprehensive digital expression analysis of public gene expression data revealed that most(~80%)rice GTs are expressed.Based on analysis with Inparanoid,we identified 282'rice-diverged'GTs that lack orthologs in sequenced dicots(Arabidopsis thaliana,Populus tricocarpa,Medicago truncatula.and Ricinus communis).Combining these analyses,we identified 33 rice-diverged GT genes(45 gene models)that are highly expressed in above-ground,vegetative tissues.From the literature and this analysis,21 of these Ioci are excellent targets for functional examination toward understanding and manipuIating grass cell wall qualities.Study of the remainder may reveal aspects of hormone and protein metabolism that are critical for rice biology.This list of 33 genes and the Rice GT Database will facilitate the

  8. Effects of Bicarbonate and High pH Conditions on Zinc and Other Nutrients Absorption in Rice

    LU Zhong-xian; MENG Fan-hua; S. VILLAREAL; WEI You-zhang; YU Xiao-ping; YANG Xiao-e; K. L. HEONG; LIN Jian-jun; HU Cui; LIU Jian-xiang

    2004-01-01

    Zinc deficiency was widely observed in calcareous soil where bicarbonate and high pH were always related with low zinc availability. In a hydroponic experiment, one zinc-efficient rice (IR36) and one zinc-inefficient rice (IR26) genotypes were employed to investigate the effects of bicarbonate and high pH conditions on absorption, transport of zinc and other nutrients (P, K, Ca, Mg,Fe, Cu, Mn) in rice. As compared with the control, high pH inhibited absorption, translocation and accumulation of zinc and other nutrients in both rice genotypes. Bicarbonate had minor effect on zinc-efficient rice genotype (IR36) whereas it could decrease zinc and other nutrient absorption in zinc-inefficient rice genotype (IR26). These results implied that increasing rice tolerance to bicarbonate is one of the most important strategies to improve rice adaptation for zinc-deficit calcareous soil.

  9. Mutagenic effects on indica rice carried by satellite

    Dried seeds of four indica rice varieties were carried into space by satellite Shijia No.8, the mutagenic effects of space condition on the seeds vigor and agronomic traits in the SP1 generation, and on the agronomic traits, amylose conent and bacterial resistance in the SP2 generation were studied. The results showed that the space condition slightly damaged rice seeds, with the physiological damage rate of germination rate, bud length, plant height and seed-setting rate in the SP1 ranged from 0 to 26.9%. Different varieties responded differently to the space conditions, and the order from strong to weak was Gui 99, Hanghui 7, R998, Jinhang 138. Compared with the control, no trait showed segregation in the SP1 generation. Some traits appeared larger segregation in the SP2 generation, and the mutants of plant height, number of tillers, weight of grain, amylose content and bacterial blight resistance were isolated in the SP2 generation, and these mutation traits could be inherited the SP3 generation. Space conditions not only produced mutants of rice agronomic traits, but also produced mutants of rice quality and disease resistance. (authors)

  10. Mutation induction of protein variability in wheat and rice

    No high protein mutants of wheat have been obtained without depression of grain yield after screening a few thousand lines. The best wheat mutant identified in our programme so far is an erectoid mutant that has consistently shown about 1.5-2% points increase in protein over Kalyan sona for the last four years. Grain yield of the mutant is about 89% of the parent. No significant variation in amino composition is noted in the mutant. Preliminary analysis of over 200 macro mutants in three varieties of rice has resulted in identification of mutants with high protein content (10-22%) compared with 8.0 to 8.5% in the high yielding controls. The amino-acid composition of some of the mutant kernels do not show great deviation from the controls. All the high protein percentage mutants are lower in grain yield. Despite very high F1 sterility in a cross involving the high protein genotype GMPR-51 and high yielding IR-8, several fertile F2 plants resembling IR-8 have been isolated which on preliminary analysis have shown still higher protein content than GMPR-51, suggesting a transgressive mode of inheritance of this trait. (author)

  11. Breeding of a new special rice variety Hangxiangnuo

    A new special rice variety Hangxiangnuo was bred by several generation selections of the progeny of the rice variety Nanfengnuo which was carried by the spacecraft Shenzhou No 4. Hangxiangnuo was permitted to release by the Crop Examination and Approval Committee of Guangdong Province in January, 2009. Compared with its parent variety Nanfengnuo, Hangxiangnuo has better resistance to blast, greater length-width ratio of grain, more panicles per plant, filled grains per panicle and fragrance. The efficiency of space mutation breeding and the generation at which mutant traits become homozygous were also discussed in the paper. (authors)

  12. Targeting oncogenic mutant p53 for cancer therapy

    Tomoo eIwakuma; Alejandro eParrales

    2015-01-01

    Among genetic alterations in human cancers, mutations in the tumor suppressor p53 gene are the most common, occurring in over 50% of human cancers. The majority of p53 mutations are missense mutations and result in the accumulation of dysfunctional p53 protein in tumors. These mutants frequently have oncogenic gain-of-function (GOF) activities and exacerbate malignant properties of cancer cells, such as metastasis and drug resistance. Increasing evidence reveals that stabilization of mutant p...

  13. Targeting Oncogenic Mutant p53 for Cancer Therapy

    Parrales, Alejandro; Iwakuma, Tomoo

    2015-01-01

    Among genetic alterations in human cancers, mutations in the tumor suppressor p53 gene are the most common, occurring in over 50% of human cancers. The majority of p53 mutations are missense mutations and result in the accumulation of dysfunctional p53 protein in tumors. These mutants frequently have oncogenic gain-of-function activities and exacerbate malignant properties of cancer cells, such as metastasis and drug resistance. Increasing evidence reveals that stabilization of mutant p53 in ...

  14. Health Risk Assessment of Heavy Metals in Rice to the Population in Zhejiang, China

    Huang, Zhu; Pan, Xiao-dong; Wu, Ping-Gu; Han, Jian-Long; Chen, Qing

    2013-01-01

    Environmental pollution with toxic heavy metals can lead to the possible contamination of the rice. Selected metals (As, Cd, Hg and Pb) and their accumulation in rice collected from Zhejiang, China were analyzed to evaluate the potential health risk to the local adults and children. The mean levels found in rice were as follows: As, 0.080 mg/kg; Cd, 0.037 mg/kg; Hg, 0.005 mg/kg; Pb, 0.060 mg/kg. The estimated daily intakes (EDIs) were calculated in combination of the rice consumption data. Th...

  15. [Pigment composition and photosynthetic activity of pea chlorophyll mutants].

    Ladygin, V G

    2003-01-01

    Pea chlorophyll mutants chlorotica 2004 and 2014 have been studied. The mutants differ from the initial form (pea cultivar Torsdag) in stem and leaf color (light green in the mutant 2004 and yellow-green in the mutant 2014), relative chlorophyll content (approximately 80 and 50%, respectively), and the composition of carotenoids: the mutant 2004 contains a significantly smaller amount of carotene but accumulates more lutein and violaxanthine; in the mutant 2014, the contents of all carotenoids are decreased proportionally to the decrease in chlorophyll content. It is shown that the rates of CO2 assimilation and oxygen production in the mutant chlorotica 2004 and 2014 plants are reduced. The quantum efficiency of photosynthesis in the mutants is 29-30% lower than in the control plants; in their hybrids, however, it is 1.5-2 higher. It is proposed that both the greater role of dark respiration in gas exchange and the reduced photosynthetic activity in chlorotica mutants are responsible for the decreased phytomass increment in these plants. On the basis of these results, the conclusion is drawn that the mutations chlorotica 2004 and 2014 affect the genes controlling the formation and functioning of various components of the photosynthetic apparatus. PMID:12942751

  16. Processing Conditions, Rice Properties, Health and Environment

    Roy, Poritosh; Orikasa, Takahiro; Okadome, Hiroshi; Nakamura, Nobutaka; Shiina, Takeo

    2011-01-01

    Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR), germinated brown rice (GBR) and partially-milled rice (PMR) contains more health beneficial food components compared to the well milled rice (WMR). Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR) seems to be relatively prone to...

  17. Rice (Oryza) hemoglobins

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  18. Development of new semidwarf sources for rice with different cytoplasms (CV Basmati 370 and Gloria)

    In Cuba semidwarf rice varieties grow on 98% of the area. Virtually all carry the same Dee-geo-won-gen dwarfing gene. Also, most if not all the cultivars have the same cytoplasm. The induced mutations approach was undertaken in order to generate alternative genetic sources of dwarfing with different cytoplasms and to improve the grain quality of Cuban rice. The seeds of two varieties, Basmati 370 and Gloria, were irradiated with 200 and 300 Gy of 60Co gamma rays. In several generations of selection, progeny testing and preliminary yield tests 10 mutants (6 from Basmati 370 and 4 from Gloria), whose yields exceeded the source cultivars, have been advanced to replicated yield trials. Some of the mutant lines are also resistant to lodging and to blast (Pyricularis grisea). It is concluded the induced mutations can be used successfully to improve plant type and other agronomic traits in rice. The induced mutants will be used also in hybridization programs. (author)

  19. The Use Of GAMMA Irradiation To Produce Drought Resistant Rices

    Rice is one of the most important food crops for human. Among factors such as climate, soil, weed and pest, drought is a major constraint to the rice production. Therefore, besides the production of high yield, the development of drought resistant rice for upland is a practical sense requirement. C71 is the blast resistant cultivar having good quality and has been widely grown in Northern provinces. However, its drought resistance is at intermediate level. In this paper, we present the results on the use of gamma irradiation in production of drought resistant mutants in C71 rice cultivar with an attempt to develop this cultivar for water-limited prone. The dry seeds of C71 were irradiated with the doses of 10, 15, 20, 25, 30, 35 and 40 krad. After irradiation, the seeds were germinated, and 10 days-old seedlings were treated with PEG 6000 for artificial drought screening. The results on PEG treatments, showed that the survival percentages of irradiated lines were increased comparing to the control lines. The molecular analysis indicated that there were alterations in the genome of the obtained rice lines. The lines could be useful material for development of drought resistant rice. (author)

  20. Productive mutants of niger

    Seeds of six niger (Guizotia abyssinica Cass.) varieties ('GA-10', 'ONS-8', 'IGP-72', 'N-71', 'NB-9' and 'UN-4') were treated with 0.5, 0.75 and 1% ethyl methanesulphonate. After four generations of selection, 29 mutant lines were developed and those were evaluated from 1990-92 during Kharif (July to October) and Rabi (December to March) seasons. Average plant characteristics and yield data of four high yielding mutants along with 'IGP-76' (National Check), GA-10 (Zonal Check) and 'Semiliguda Local' (Local Check) are presented

  1. Radioisotopes and rice

    To stimulate research into problems of rice cultivation, the International Atomic Energy Agency has placed several research contracts with agricultural institutes in some of its Member States. Some of these research projects deal with problems of soil-plant relations and fertilization, and rice is one of the main crops on which studies are being made. A panel of experts convened by the Agency met in Vienna in May this year to discuss some of the outstanding problems in the uses of radioisotopes in soil-plant relations and fertilization studies, and problems concerning rice were among the principal subjects considered. In a paper presented at the panel meeting. Professor S. Mitsui, of the University of Tokyo, reviewed some of the main uses of radioisotopes in studying problems of rice soils and rice cultivation and suggested several specific topics in this field which could be investigated by isotope techniques

  2. Comparative Proteomic Analysis of Rice Shoots Exposed to High Arsenate

    Yanli Liu; Ming Li; Chao Han; Fengxia Wu; Bingkun Tu; Pingfang Yang

    2013-01-01

    Consumption of arsenic contaminated water and cereals is a serious threat to humans all over the world. Rice (Oryza sativa“Nipponbare”), as a main cereal crop, can accumulate arsenic more than 10-fold that of in other cereals. To gain a comprehensive understanding of the response of rice subjected to 100 mM arsenate stress, a comparative proteomic analysis of rice shoots in combination with morphological and biochemical investigations have been performed in this study. The results demonstrated that arsenate suppressed the growth of rice seedlings, destroyed the cellular ultra-structure and changed the homeostasis of reactive oxygen species. Moreover, a total of 38 differentially displayed proteins, which were mainly involved in metabolism, redox and protein-metabolism, were identified. The data suggest the arsenic can inhibit rice growth through negatively affecting chloroplast structure and photosynthesis. In addition, upregulation of the proteins involved in redox and protein metabolism might help the rice to be resistant or tolerant to arsenic toxicity. In general, this study improves our understanding about the rice arsenic responsive mechanism.

  3. Rice Varietal Improvement and International Exchange of Rice Germplasm

    Evenson, Robert E.

    1997-01-01

    Rice is the most important food grain in developing countries. Rapid population growth in developing countries during the 1950s and 1960s presented a massive challenge to rice producers. Rice production would have to be expanded at historically unprecedented rates to maintain per capita rice consumption levels. That challenge was met. Rice production expanded more rapidly than population. The challenge was met primarily by increased yields per hectare of land. This paper documents the role of...

  4. [Production of mutants with an increased alpha-amylase synthesis].

    Ostrikova, N A; Konovalov, S A

    1978-01-01

    A mutant characterized by elevated biosynthesis of alpha-amylase was obtained as a result of a three-stage induced selection using nitroso compounds. Changes of mutagens in the course of selection stages and the establishment of their effective doses causing the maximum accumulation of mutations yielded the mutant which produced 2.5 times more alpha-amylase than the parent strain of Aspergillus oryzae 762. The induced variability of the mutant can be registered on a solid growth medium and provides the high activity of alpha-amylase. PMID:309059

  5. Methods of producing protoporphyrin IX and bacterial mutants therefor

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  6. Constitutive expression of OsIAA9 affects starch granules accumulation and root gravitropic response in Arabidopsis

    Sha eLuo

    2015-12-01

    Full Text Available Auxin/Indole-3-Acetic Acid (Aux/IAA genes are early auxin response genes ecoding short-lived transcriptional repressors, which regulate auxin signaling in plants by interplay with Auxin Response Factors (ARFs. Most of the Aux/IAA proteins contain four different domains, namely Domain I, Domain II, Domain III and Domain IV. So far all Aux/IAA mutants with auxin-related phenotypes identified in both Arabidopsis and rice (Oryza sativa are dominant gain-of-function mutants with mutations in Domain II of the corresponding Aux/IAA proteins, suggest that Aux/IAA proteins in both Arabidopsis and rice are largely functional redundantly, and they may have conserved functions. We report here the functional characterization of a rice Aux/IAA gene, OsIAA9. RT-PCR results showed that expression of OsIAA9 was induced by exogenously applied auxin, suggesting that OsIAA9 is an auxin response gene. Bioinformatic analysis showed that OsIAA9 has a repressor motif in Domain I, a degron in Domain II, and the conserved amino acid signatures for protein-protein interactions in Domain III and Domain IV. By generating transgenic plants expressing GFP-OsIAA9 and examining florescence in the transgenic plants, we found that OsIAA9 is localized in the nucleus. When transfected into protoplasts isolated from rosette leaves of Arabidopsis, OsIAA9 repressed reporter gene expression, and the repression was partially released by exogenously IAA. These results suggest that OsIAA9 is a canonical Aux/IAA protein. Protoplast transfection assays showed that OsIAA9 interacted ARF5, but not ARF6, 7, 8 and 19. Transgenic Arabidopsis plants expressing OsIAA9 have increased number of lateral roots, and reduced gravitropic response. Further analysis showed that OsIAA9 transgenic Arabidopsis plants accumulated fewer granules in their root tips and the distribution of granules was also affected. Taken together, our study showed that OsIAA9 is a transcriptional repressor, and it regulates

  7. Variation among Rice Cultivars in Root Acidification and Its Relation to Cadmium Uptake

    LIU Jian-guo; XU Hai; CAI Guo-liang; QIAN Min; WANG De-ke; ZHU Qing-sen

    2006-01-01

    To understand the mechanisms of Cd uptake and accumulation in rice, soil acidification by root activities was investigated in six rice cultivars differing in Cd accumulation. The results showed a significant difference among the cultivars in pH of pot water and root exudate. Soil acidification abilities varied with rice cultivars. Both pH of pot water and root exudate were lower in indica cultivars than in japonica ones. The difference in root acidification was larger in Cd treated cultivars than the control. Under Cd stress, the pH of pot water and root exudate correlated negatively and significantly with Cd concentrations in rice plants. It was suggested that the soil acidification by root exudates, especially in Cd contaminated soils, may be one of the mechanisms responsible for Cd uptake in rice cultivars.

  8. Endosperm Development in Autotetraploid Rice

    WANG Lan; LIU Xiang-dong; LU Yong-gen; FENG Jiu-huan; XU Xue-bin; XU Shi-xiong (S.Y.Zee)

    2005-01-01

    By using the laser scanning confocal microscope and plastic (Leica 7022 historesin embedding kit) semi-thin sectioningtechnique, comparative studies on the development of endosperm were carried out between autotetraploid and diploid rices. Aboutone third of the ovaries in the autotetraploid showed normal endosperm development as those in the diploid. In these ovaries, one ofthe polar nuclei would fuse with the sperm nucleus, and the primary endosperm nucleus formed and underwent the first division in 4hours after pollination; the anticlinal wall began to grow centripetally between the free nuclei starting from the wall ingrowths of theembryo sac near the micropylar end, and some of the phragmoplasts formed transformed into periclinal walls. In addition, some of thecell wall situated in the middle of the endosperm appeared to originate from phragmoplasts, whereas others seemed to developrandomly without the obvious formation of phragmoplasts. Cellulose began to accumulate in the wall of aleurone cell layer at 6 daysafter pollination. The cellulose wall of the cells of the aleurone cell layer appeared to have completely formed within 7 to 8 days afterpollination. On the other hand, about two thirds of the ovaries in the autotetraploid showed abnormality in endosperm developmentwith various types, such as non-fertilization, abnormal fertilization, endosperm development-delay and non-synchronization in thedevelopment of cellulose wall of cells of the aleurone layer. These abnormalities usually resulted in decreased seed setting inautotetraploid rice.

  9. Rice improvement through induction of mutations with gamma rays

    The objective of this research was to induce mutations for early maturity, resistance or tolerance to blast (Pyricularia grisea), and high yield potential in the rice (O. sativa) varieties ICTA Virginia and Precozicta. Six thousand seeds of each variety were irradiated and the M1 generation was grown. The irradiation doses for Precozicta and ICTA Virginia were 31 and 29 krad (310 and 290 Gy), respectively. One row from each plant selected in the M1 generation was sown in the field. Mutants that possessed high yield potential, early maturity, resistance to blast, chlorophyll deficiencies, and morphological differences were identified and selected. The M3 generation of mutants identified in the M2 generation was sown in the field to confirm the M2 classifications. Early maturing and blast resistant mutants were harvested. Forty eight mutant lines selected in the M3 generation were evaluated in replicated field plots in the M4 generation. (author). 7 refs, 3 figs, 5 tabs

  10. A mutation in the rice chalcone isomerase gene causes the golden hull and internode 1 phenotype.

    Hong, Lilan; Qian, Qian; Tang, Ding; Wang, Kejian; Li, Ming; Cheng, Zhukuan

    2012-07-01

    The biosynthesis of flavonoids, important secondary plant metabolites, has been investigated extensively, but few mutants of genes in this pathway have been identified in rice (Oryza sativa). The rice gold hull and internode (gh) mutants exhibit a reddish-brown pigmentation in the hull and internode and their phenotype has long been used as a morphological marker trait for breeding and genetic study. Here, we characterized that the gh1 mutant was a mutant of the rice chalcone isomerase gene (OsCHI). The result showed that gh1 had a Dasheng retrotransposon inserted in the 5′ UTR of the OsCHI gene, which resulted in the complete loss of OsCHI expression. gh1 exhibited golden pigmentation in hulls and internodes once the panicles were exposed to light. The total flavonoid content in gh1 hulls was increased threefold compared to wild type. Consistent with the gh1 phenotype, OsCHI transcripts were expressed in most tissues of rice and most abundantly in internodes. It was also expressed at high levels in panicles before heading, distributed mainly in lemmas and paleae, but its expression decreased substantially after the panicles emerged from the sheath. OsCHI encodes a protein functionally and structurally conserved to chalcone isomerases in other species. Our findings demonstrated that the OsCHI gene was indispensable for flux of the flavonoid pathway in rice. PMID:22286805

  11. Rice Germplasm Resources in China

    YINGCunshan

    1994-01-01

    China is one of the origin countries in Asia of cultiv ated rice (O. sativaL.), and rice is one of the aged-long food crops in the country. The results of the 14C evaluation on the carbonified rice grains unearthed from Hemudu in Yuyao County and Luojiajiao in Tongxiang County of Zhejiang Province indicated that rice in these area has been planted more than 7,000 yrs and indica (hsien) and japonica (keng) rices coexisted with each other.

  12. A Century of Rice Innovations

    Halos, Saturnina C.

    2005-01-01

    Rice innovations are technologies and practices extensively adopted so as to change production practices and productivity. This paper documents the changes in rice productivity, policy and institutions in the last 100 years and identifies the technological change that may have affected rice productivity. One hundred years has totally changed rice production practices and improved productivity. Technical innovations that helped improved rice productivity include irrigation, pest management not...

  13. Studies on induction of blast-resistant mutation in rice

    The mutation frequency of blast resistance in rice and that of increased pathogenicity of blast fungi were examined, using the rice variety, Norin 8, which is susceptible to all races of blast fungi in Japan, and a fungus strain, Ina 168, which carries 6 virulent genes, respectively. Four different inoculation methods were employed for screening blast resistant mutants, i.e., spraying spore suspensions in growth chambers, in a greenhouse and in a field nursery, and injecting spore suspensions into newly developed tillers. The number of lesions and their types were used as the criteria of blast resistance. For screening the fungus mutants with increased pathogenicity, the spore suspensions of the fungi to be tested were sprayed on the seedlings of the blast resistant varieties, and when susceptible-type lesions were formed, single spores were isolated from these lesions, and the change in its pathogenicity was confirmed. When seeds were irradiated with gamma ray and treated with chemicals (EMS or EI), the frequency of the mutants with high resistance to blast was 5/4,575 and 4/5,851 respectively, in the M2 generation. The frequency of dominant blast resistant mutations following gamma-ray irradiation at the pre-embryo stage of growing plants was 3/60,101 in the M1 generation. When the spore suspensions of blast fungi were treated with X-ray, the frequency of the mutants with increased pathogenicity was about 0.5%. Thus, the mutants highly resistant against blast of rice induced by radiation or chemicals would eventually become susceptible varieties because blast fungus mutants occurred more frequently with increased pathogenicity. (Kaihara, S.)

  14. Radiation use efficiency of rice under different planting methods and environmental conditions

    Radiation use efficiency is an important parameter which has often been used in many crop growth models to estimate total biomass and yield. Studies of the relationships between above-ground biomass and accumulative absorbed photosynthetically active radiation (PARa, MJ/square m) of rice were examined both on-farms and on-station in Phatthalung. Planting methods were wet-sown and transplanted rice for Suphanburi 90 in the 1993 dry season and Chieng in the 1993-94 wet season. Solar radiation of the two growing seasons were calculated from climatic data. The objectives of this experiment were (1) to know the pattern of relationship between above-ground biomass and accumulative absorbed PAR of rice cultivars grown in South Thailand, (2) to compare the radiation use efficiency of rice cultivars under different planting methods and (3) to obtain the primary data for rice growth modelling in the southern climate. Results presented that only the duration of first growing period up to stem elongation in both cultivars, above-ground biomass and leaf area index were higher in wet-sown than in transplanted rice. Relationship between above-ground biomass accumulation through growing period and accumulative absorbed PAR was in positive linear regression with R*[2)0.85. Erect leaf of Suphanburi 90 had a radiation use efficiency (RUE, g/MJ) higher than non-erect leaf of Chieng. A problem of weed infestation in wet-sown rice in both cultivars had an effect on the RUE which were highly significant lower than transplanted rice. The Rue of wet-sown and transplanted rice were 2.77 and 3.20 g/MJ, respectively for Suphanburi 90, 2.13 and 2.67 g/MJ for Chieng. These results suggest that when dealing with radiation use efficiency in the rice growth modelling the differences of cultivars and planting methods should be taken into consideration

  15. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    Zhouping Liu

    2015-12-01

    Full Text Available Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM. This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  16. Rice OsVAMP714, a membrane-trafficking protein localized to the chloroplast and vacuolar membrane, is involved in resistance to rice blast disease.

    Sugano, Shoji; Hayashi, Nagao; Kawagoe, Yasushi; Mochizuki, Susumu; Inoue, Haruhiko; Mori, Masaki; Nishizawa, Yoko; Jiang, Chang-Jie; Matsui, Minami; Takatsuji, Hiroshi

    2016-05-01

    Membrane trafficking plays pivotal roles in many cellular processes including plant immunity. Here, we report the characterization of OsVAMP714, an intracellular SNARE protein, focusing on its role in resistance to rice blast disease caused by the fungal pathogen Magnaporthe oryzae. Disease resistance tests using OsVAMP714 knockdown and overexpressing rice plants demonstrated the involvement of OsVAMP714 in blast resistance. The overexpression of OsVAMP7111, whose product is highly homologous to OsVAMP714, did not enhance blast resistance to rice, implying a potential specificity of OsVAMP714 to blast resistance. OsVAMP714 was localized to the chloroplast in mesophyll cells and to the cellular periphery in epidermal cells of transgenic rice plant leaves. We showed that chloroplast localization is critical for the normal OsVAMP714 functioning in blast resistance by analyzing the rice plants overexpressing OsVAMP714 mutants whose products did not localize in the chloroplast. We also found that OsVAMP714 was located in the vacuolar membrane surrounding the invasive hyphae of M. oryzae. Furthermore, we showed that OsVAMP714 overexpression promotes leaf sheath elongation and that the first 19 amino acids, which are highly conserved between animal and plant VAMP7 proteins, are crucial for normal rice plant growths. Our studies imply that the OsVAMP714-mediated trafficking pathway plays an important role in rice blast resistance as well as in the vegetative growth of rice. PMID:26879413

  17. Application of gamma-ray irradiation technique to select, create and develop super rice with high quality to substitute the imported hybrid rice

    Three varieties NPT3, BQ and TQ14 were selected by irradiation ray source Gamma Co-60 with dry seed, 13% grain moisture and created at 25-30 krad. NPT3 is super rice varieties with characteristics such as: extremely short growing period (105-110 day crop; 130- 135 days in the spring, the average yield of 9-10 tones/ha), quality, stem, leaf stand, suitable for intensive capability, able to resist pests and unfavorable conditions especially the elements of productivity (amylase from 15-16%) and mass produced including hybrid rice as Nhi Uu 868, Thien Nguyen Uu 9, HYT100, etc. BQ rice varieties were high quality, average productivity gain of 7.5- 8.0 ton/ha, equivalent to hybrid rice, short growth period (105-110 days in summer season; 120- 130 days in spring season), and quality rice: content 18-20% amylose, rice delicious, supple as BC15. TQ14 varieties was planted in 2 seasons/ year, with agricultural and biological characteristics as Khang-Dan18 mutant with wide adaptation, high yield potential, the average gain from 5.9 to 6.2 tones/ha, short growth period (105-110 days in summer season, 130-135 days in spring season), insect resistance, quality of rice suitable for manufacturing technology like noodles, instant noodles, rice noodles, Ethanol. (author)

  18. R-acetoin accumulation and dissimilation in Klebsiella pneumoniae.

    Wang, Dexin; Zhou, Jidong; Chen, Chuan; Wei, Dong; Shi, Jiping; Jiang, Biao; Liu, Pengfu; Hao, Jian

    2015-08-01

    Klebsiella pneumoniae is a 2,3-butanediol producer, and R-acetoin is an intermediate of 2,3-butanediol production. R-acetoin accumulation and dissimilation in K. pneumoniae was studied here. A budC mutant, which has lost 2,3-butanediol dehydrogenase activity, accumulated high levels of R-acetoin in culture broth. However, after glucose was exhausted, the accumulated R-acetoin could be reused by the cells as a carbon source. Acetoin dehydrogenase enzyme system, encoded by acoABCD, was responsible for R-acetoin dissimilation. acoABCD mutants lost the ability to grow on acetoin as the sole carbon source, and the acetoin accumulated could not be dissimilated. However, in the presence of another carbon source, the acetoin accumulated in broth of acoABCD mutants was converted to 2,3-butanediol. Parameters of R-acetoin production by budC mutants were optimized in batch culture. Aerobic culture and mildly acidic conditions (pH 6-6.5) favored R-acetoin accumulation. At the optimized conditions, in fed-batch fermentation, 62.3 g/L R-acetoin was produced by budC and acoABCD double mutant in 57 h culture, with an optical purity of 98.0 %, and a substrate conversion ratio of 28.7 %. PMID:26059458

  19. Transfer to rice

    One of the critical foods for the intake of radionuclides by humans is rice (Oryza sativa L.), which is the dominant staple food crop in humid tropical and sub-tropical countries across the globe. Cultivation methods have important effects on plant uptake of radionuclides from soil. Most rice is produced under flooded conditions, i.e. in fields with a water layer of 5-15 cm deep on soil. This is unlike the situation in unsaturated fields where the soil conditions are significantly different, meaning that the soil-to-rice transfer factors (Fvs) need to be discussed separately from Fv values of other cereals grown under unsaturated field conditions. In this section, rice refers to the crop grown on wet paddy fields; since water management is the dominant method for rice cultivation this is the most common type. Rice Fv values were collected from papers in international journals, books and proceedings with peer reviewing processes and Fv values based on dry weight rice grain were summarized here. Fv data for fallout isotopes (e.g. 90Sr and 137Cs), neutron activation products (e.g. 54Mn, 60Co, etc.) or naturally existing radionluclides (e.g. 210Pb, 226Ra, 238U, etc.) and those for naturally existing stable elements under agricultural field conditions were listed. (author)

  20. N-glycan containing a core α1,3-fucose residue is required for basipetal auxin transport and gravitropic response in rice (Oryza sativa).

    Harmoko, Rikno; Yoo, Jae Yong; Ko, Ki Seong; Ramasamy, Nirmal Kumar; Hwang, Bo Young; Lee, Eun Ji; Kim, Ho Soo; Lee, Kyung Jin; Oh, Doo-Byoung; Kim, Dool-Yi; Lee, Sanghun; Li, Yang; Lee, Sang Yeol; Lee, Kyun Oh

    2016-10-01

    In plants, α1,3-fucosyltransferase (FucT) catalyzes the transfer of fucose from GDP-fucose to asparagine-linked GlcNAc of the N-glycan core in the medial Golgi. To explore the physiological significance of this processing, we isolated two Oryza sativa (rice) mutants (fuct-1 and fuct-2) with loss of FucT function. Biochemical analyses of the N-glycan structure confirmed that α1,3-fucose is missing from the N-glycans of allelic fuct-1 and fuct-2. Compared with the wild-type cv Kitaake, fuct-1 displayed a larger tiller angle, shorter internode and panicle lengths, and decreased grain filling as well as an increase in chalky grains with abnormal shape. The mutant allele fuct-2 gave rise to similar developmental abnormalities, although they were milder than those of fuct-1. Restoration of a normal tiller angle in fuct-1 by complementation demonstrated that the phenotype is caused by the loss of FucT function. Both fuct-1 and fuct-2 plants exhibited reduced gravitropic responses. Expression of the genes involved in tiller and leaf angle control was also affected in the mutants. We demonstrate that reduced basipetal auxin transport and low auxin accumulation at the base of the shoot in fuct-1 account for both the reduced gravitropic response and the increased tiller angle. PMID:27241276

  1. Induced mutations for a determinate habit in rice bean

    Induced mutation techniques were used to create polygenic variability in rice bean (Vigna umbellata). Dry seeds of the genotype (sel. I) were irradiated with 40-80 kR of gamma rays at 10 kR intervals. A wide variation in quantitative characters was induced in both the M2 and M3 generations. Some mutants were isolated that showed a determinate growth habit, earliness, a high yield and photoinsensitivity. These mutants were found to be breeding true. (author). 5 refs, 1 tab

  2. Anaerobic conditions improve germination of a gibberellic acid deficient rice

    Frantz, Jonathan M.; Bugbee, Bruce

    2002-01-01

    Dwarf plants are useful in research because multiple plants can be grown in a small area. Rice (Oryza sativa L.) is especially important since its relatively simple genome has recently been sequenced. We are characterizing a gibberellic acid (GA) mutant of rice (japonica cv 'Shiokari,' line N-71) that is extremely dwarf (20 cm tall). Unfortunately, this GA mutation is associated with poor germination (70%) under aerobic conditions. Neither exogenous GA nor a dormancy-breaking heat treatment improved germination. However, 95% germination was achieved by germinating the seeds anaerobically, either in a pure N2 environment or submerged in unstirred tap water. The anaerobic conditions appear to break a mild post-harvest dormancy in this rice cultivar. Copyright 2002 Crop Science Society of America.

  3. Genetic improvement of rice (oryza sativa l.) by induced mutations

    In 1989 was initiated at Rice Research Institute of Cuba, a mutation breeding programme, in order to obtain new germoplasm with improved characters such as milling quality, earliness, resistance to the Hoja Blanca virus disease and salt tolerance. Seven varieties has been irradiated and two different sources of radiation were used: gamma rays from 60Co and fast neutrons of a 14 MeV neutron generator. In 1995, was released the variety IACuba 23 for low inputs conditions. Another four varieties IACuba 21, IACuba 22, IACuba 27 and IACuba 28 are in validation trials in rice production areas under irrigated condition. The last two have showed resistance to Steneotarsonemus spinki. Also, a group of mutants was selected to be used as parents. These mutants have been used in 953 crosses

  4. Physiological and molecular characterization of Si uptake in wild rice species.

    Mitani-Ueno, Namiki; Ogai, Hisao; Yamaji, Naoki; Ma, Jian Feng

    2014-07-01

    Cultivated rice (Oryza sativa) accumulates high concentration of silicon (Si), which is required for its high and sustainable production. High Si accumulation in cultivated rice is achieved by a high expression of both influx (Lsi1) and efflux (Lsi2) Si transporters in roots. Herein, we physiologically investigated Si uptake, isolated and functionally characterized Si transporters in six wild rice species with different genome types. Si uptake by the roots was lower in Oryza rufipogon, Oryza barthii (AA genome), Oryza australiensis (EE genome) and Oryza punctata (BB genome), but similar in Oryza glumaepatula and Oryza meridionalis (AA genome) compared with the cultivated rice (cv. Nipponbare). However, all wild rice species and the cultivated rice showed similar concentration of Si in the shoots when grown in a field. All species with AA genome showed the same amino acid sequence of both Lsi1 and Lsi2 as O. sativa, whereas species with EE and BB genome showed several nucleotide differences in both Lsi1 and Lsi2. However, proteins encoded by these genes also showed transport activity for Si in Xenopus oocyte. The mRNA expression of Lsi1 in all wild rice species was lower than that in the cultivated rice, whereas the expression of Lsi2 was lower in O. rufipogon and O. barthii but similar in other species. Similar cellular localization of Lsi1 and Lsi2 was observed in all wild rice as the cultivated rice. These results indicate that superior Si uptake, the important trait for rice growth, is basically conserved in wild and cultivated rice species. PMID:24320720

  5. Methylmercury varies more than one order of magnitude in commercial European rice.

    Brombach, Christoph-Cornelius; Manorut, Parinda; Kolambage-Dona, Piumi P P; Ezzeldin, Mohammed Farouk; Chen, Bin; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2017-01-01

    Rice is known to accumulate methylmercury (MeHg) in the rice grains. MeHg as a neurotoxin impacts on the human central nervous systems and especially on the developing brain. In this exploratory study, 87 commercial rice products sold in Europe, including nine baby-rice products, were analyzed for total Hg and MeHg content. MeHg concentration in all rice products investigated range from 0.11 to 6.45μgkg(-1) with an average value of 1.91±1.07μgkg(-1) and baby-rice is not significantly different from other rice products. Total Hg ranges from 0.53 to 11.1μgkg(-1) with an average of 3.04±2.07μgkg(-1). MeHg concentrations in all rice products studied in this work would not exceed the provisional tolerable weekly intake (PTWI). 30% of all commercial market rice products exceeded 10% of the PTWI calculated for toddlers or 13% of products for adults with rice based diet. PMID:27507486

  6. Plant regeneration from mesophyll protoplast of indica rice Qiugui'ai 11 (Oryza sativa L.)

    JIANYuyu; JintaanankulSuwan

    1998-01-01

    In the recent decade, plant regeneration from protoplast has been obtained through embryogenic cell suspension cultures of rice. However, not only the establishment of embryogenic call suspension cultures of rice was difficult, but also the protoplasts became less and less regenerable and the genetic change was gradu ally accumulated during the prolonged culture.Since 1976 (Deka.), extensive efforts have been made to induce sustained division and regenerate plants from rnesophyll protoplasts of rice, but not successful.

  7. Effects of Nitrogen Application Level on Rice Nutrient Uptake and Ammonia Volatilization

    YU Qiao-gang; YE Jing; YANG Shao-na; FU Jian-rong; MA Jun-wei; SUN Wan-chun; JIANG Li-na

    2013-01-01

    The effects of different nitrogen application levels on nutrient uptake and ammonia volatilization were studied with the rice cultivar Zheyou 12 as a material.The accumulative amounts of nitrogen,phosphorus and potassium in rice plants across all growth stages showed a trend to increase with increasing nitrogen application levels from 0 to 270 kg/hm2,but decreased at nitrogen application levels exceeding 270 kg/hm2.Moreover,the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants was increased by application of organic manure in combination with 150 kg/hm2 nitrogen.The nitrogen uptake was high during the jointing to heading stages.Correlation analysis showed that rice yield was positively correlated with the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants.The highest correlation coefficient observed was between the amount of nitrogen uptake and rice yield.The rate and accumulative amounts of ammonia volatilization increased with increasing nitrogen fertilizer application level.Compared with other stages,the rate and accumulative amount of ammonia volatilization were higher after base fertilizer application.The ammonia volatilization rates in response to the nitrogen application levels of 270 kg/hm2 and 330 kg/hm2 were much higher than those in the other treatments.The loss of nitrogen through ammonia volatilization accounted for 23.9% of the total applied nitrogen at the nitrogen application level of 330 kg/hm2.

  8. Protein fingerprint diversification of rice seeds

    Lu, Weihong; Sun, Yeqing; Zheng, Qi; Guan, Shuanghong

    To study protein fingerprint diversification of rice seeds induced by space environment we selected three series mutants induced in Chinese recoverable satellite in 1996 for 15 days including 1 Series 971 971ck the control sample in ground 971-5 and 971-4 samples after space derivation 2 Series 972 972ck the control sample in ground 972-4 and 972-1 samples after space derivation 3 Series 974 974ck the control sample in ground 974-5 and 974-8 samples after space derivation The proteins were extracted and separated to 4 groups Albumin Globulin Prolamine and Glutelin from the seeds of ground control group and inducted by space environment group Using RPLC method Reference peak was selected in every group and its relative retention time was 1 000 The relative retention time of other peaks was the ratio Calculate the contents due to the peak areas and draw a conclusion that some contents of protein were changed in the seeds of the mutant varieties There are character peaks among different varieties as the fingerprint Comparative analysis the fingerprint of Albumin Globulin and Prolamine can find the different in varieties identify The protein express abundance and easy be detected in the seeds So using RPLC method the Protein Fingerprint can identify breed handily and steadily Keywords rice seeds Space environment Protein Fingerprint

  9. Serine:glyoxylate aminotransferase mutant of barley

    A photorespiratory mutant of barley (LaPr 85/84), deficient in both of the major peaks of serine:glyoxylate aminotransferase activity detected in the wild type, also lacks serine:pyruvate and asparagine:glyoxylate aminotransferase activities. Genetic analysis of the mutation demonstrated that these three activities are all carried on the same enzyme. The mutant, when placed in air, accumulated a large pool of serine, showed the expected rate (50%) of ammonia release during photorespiration but produced CO2 at twice the wild type rate when it was fed [14C] glyoxylate. Compared with the wild type, LaPr 85/84 exhibited abnormal transient changes in chlorophyll a fluorescence when the CO2 concentration of the air was altered, indicating that the rates of the fluorescence quenching mechanisms were affected in vivo by the lack of this enzyme

  10. Breeding of new rice varieties by gamma-rays

    The breeding procedure for and the agronomic characteristics of some new rice varieties are reported. The seeds of the non-waxy variety ''Toyonishiki'' were exposed to 20 kR of gamma-ray. Two out of 20,000 panicles produced on these plants had waxy grain, and one of these brought forth a new commercial variety, ''Miyuki-mochi''. The yield of the new variety was reduced by 8% as compared with the original variety, but the heading date, culm length, panicle length and the number of panicles of the new variety were almost the same as those of the original variety. If compared with the old leading waxy variety, ''Shinano-mochi'', ''Miyuki-mochi'' is superior in yield by 15% and has high resistance to lodging and to rice blast. Seven other rice varieties were irradiated to obtain waxy mutants, and the frequency of R1 panicles carrying waxy grains was found to be 1/10,000. There was marked difference in the 1,000 grain weight of these mutants relative to those of the respective original varieties and in amylose content among the waxy mutant strains. A new Saka-mai variety (for Sake brewing), ''Miyamanishiki'', was obtained from ''Takanenishiki'' (30 kR exposure of dry seeds). The most important character for Saka-mai is to have white-core grains. An experiment with several rice varieties showed that the frequency of white core grains was about 0.15% in the control and about 0.21% in the R1 plants after irradiation. A desirable large grain strain, ''Shinho No. 12'', from ''Todorokiwase'', and a desirable mutant strain suitable as feed for domestic animals, ''Shinho No. 38'', from ''Toyonishiki'' were also obtained by gamma-ray irradiation. (Kaihara, S.)

  11. RAPD tagging of salt tolerance gene in rice

    Salinity, which is critical in determining the growth and development of plants, is a major problem affecting ever-increasing areas throughout the world. A salt tolerant rice mutant (M-20) was obtained from accession 77-170 (Oryza sativa) through EMS mutagenesis and selection in vitro. The use of 220 10-mer RAPD primers allowed the identification of a new molecular marker, whose genetic distance from a salt tolerance gene is about 16.4 cM. (author)

  12. Genetic base of Brazilian irrigated rice cultivars

    Hudson de Oliveira Rabelo

    2015-08-01

    Full Text Available The aim of this study was to estimate the genetic base of Brazilian irrigated rice cultivars released in the period from 1965 to 2012. The genealogies of the cultivars were obtained based on information from marketing folders, websites, crossings records, and scientific articles. The following factors were calculated: relative genetic contribution (RGC, accumulated genetic contribution (AGC, frequency (in percentage of each ancestor in the genealogy (FAG, number of ancestors that constitute each cultivar (NAC,number of ancestors responsible for 60%, 70%, 80% and 90% of the genetic base (NAGB, and average number of ancestor per cultivar (ANAC. The cultivars were also grouped based on the period of release (1965-1980, 1981-1990, 1991-2000 and 2001-2012. For each grouping, the previously described factors were also estimated. A total of 110 cultivars were studied and it was concluded that the genetic base of Brazilian irrigated rice cultivars is narrow.

  13. Responses of upland rice to fertilizer

    The concentration and uptake of macro nutrients, micro nutrients and toxic elements were compared to dry matter yield, biomass components and primary and secondary tillering. Plant tissue analysis of N, P, K, Ca, Mg, Cl, Fe, Mn, Na, Ca, Al, Cr, As, Th and Ce were carried out using chemical and neutron activation analysis. N and K were found to accumulate in the green vegetative biomass whereas P, Ca, Mg, Fe and Zn were bound in the dead-plus-senesced component. Compared to control, urea fertilization increased the dry matter yield and uptakes of N, P, Ca, Mg, Fe, Mn, Na, Al, Th and Ce by upland rice. In addition to similar increases; cattle manuring also increased the green vegetative biomass, secondary tillering and uptake of K, Cl, Co, Cr and As. With the exception of Th uptake, upland rice Oryza Sativa var. Seri Pelanduk subjected to cattle manuring responded better to the uptake of various elements and produced more secondary tillers

  14. Morphological mutants of garlic

    Choudhary, A.D.; Dnyansagar, V.R. (Nagpur Univ. (India). Dept. of Botany)

    1982-01-01

    Cloves of garlic (Allium sativuum Linn.) were exposed to gamma rays with various doses and different concentrations of ethylmethane sulphonate (EMS), diethyl sulphate (dES) and ethylene imine (EI). In the second and third generations, 16 types of morphological mutants were recorded with varied frequencies. Of all the mutagens used, gamma rays were found to be the most effective in inducing the maximum number of mutations followed EI, EMS and dES in that order.

  15. Morphological mutants of garlic

    Cloves of garlic (Allium sativuum Linn.) were exposed to gamma rays with various doses and different concentrations of ethylmethane sulphonate (EMS), diethyl sulphate (dES) and ethylene imine (EI). In the second and third generations, 16 types of morphological mutants were recorded with varied frequencies. Of all the mutagens used, gamma rays were found to be the most effective in inducing the maximum number of mutations followed EI, EMS and dES in that order. (author)

  16. OsHSD1, a hydroxysteroid dehydrogenase, is involved in cuticle formation and lipid homeostasis in rice.

    Zhang, Zhe; Cheng, Zhi-Jun; Gan, Lu; Zhang, Huan; Wu, Fu-Qing; Lin, Qi-Bing; Wang, Jiu-Lin; Wang, Jie; Guo, Xiu-Ping; Zhang, Xin; Zhao, Zhi-Chao; Lei, Cai-Lin; Zhu, Shan-Shan; Wang, Chun-Ming; Wan, Jian-Min

    2016-08-01

    Cuticular wax, a hydrophobic layer on the surface of all aerial plant organs, has essential roles in plant growth and survival under various environments. Here we report a wax-deficient rice mutant oshsd1 with reduced epicuticular wax crystals and thicker cuticle membrane. Quantification of the wax components and fatty acids showed elevated levels of very-long-chain fatty acids (VLCFAs) and accumulation of soluble fatty acids in the leaves of the oshsd1 mutant. We determined the causative gene OsHSD1, a member of the short-chain dehydrogenase reductase family, through map-based cloning. It was ubiquitously expressed and responded to cold stress and exogenous treatments with NaCl or brassinosteroid analogs. Transient expression of OsHSD1-tagged green fluorescent protein revealed that OsHSD1 localized to both oil bodies and endoplasmic reticulum (ER). Dehydrogenase activity assays demonstrated that OsHSD1 was an NAD(+)/NADP(+)-dependent sterol dehydrogenase. Furthermore, OsHSD1 mutation resulted in faster protein degradation, but had no effect on the dehydrogenase activity. Together, our data indicated that OsHSD1 plays a specialized role in cuticle formation and lipid homeostasis, probably by mediating sterol signaling. This work provides new insights into oil-body associated proteins involved in wax and lipid metabolism. PMID:27297988

  17. Strigolactones are required for nitric oxide to induce root elongation in response to nitrogen and phosphate deficiencies in rice.

    Sun, Huwei; Bi, Yang; Tao, Jinyuan; Huang, Shuangjie; Hou, Mengmeng; Xue, Ren; Liang, Zhihao; Gu, Pengyuan; Yoneyama, Koichi; Xie, Xiaonan; Shen, Qirong; Xu, Guohua; Zhang, Yali

    2016-07-01

    The response of the root system architecture to nutrient deficiencies is critical for sustainable agriculture. Nitric oxide (NO) is considered a key regulator of root growth, although the mechanisms remain unknown. Phenotypic, cellular and genetic analyses were undertaken in rice to explore the role of NO in regulating root growth and strigolactone (SL) signalling under nitrogen-deficient and phosphate-deficient conditions (LN and LP). LN-induced and LP-induced seminal root elongation paralleled NO production in root tips. NO played an important role in a shared pathway of LN-induced and LP-induced root elongation via increased meristem activity. Interestingly, no responses of root elongation were observed in SL d mutants compared with wild-type plants, although similar NO accumulation was induced by sodium nitroprusside (SNP) application. Application of abamine (the SL inhibitor) reduced seminal root length and pCYCB1;1::GUS expression induced by SNP application in wild type; furthermore, comparison with wild type showed lower SL-signalling genes in nia2 mutants under control and LN treatments and similar under SNP application. Western blot analysis revealed that NO, similar to SL, triggered proteasome-mediated degradation of D53 protein levels. Therefore, we presented a novel signalling pathway in which NO-activated seminal root elongation under LN and LP conditions, with the involvement of SLs. PMID:27194103

  18. Irradiation of mutants of rose

    Radiation-induced Reddish-orange (R) and Pink (P) flowered mutants of the rose cultivar Montezuma were subjected to a second treatment of gamma radiation. Effects of this treatment were recorded on bud-take, growth, survival, flowering and essential oil content. The P mutant was more radiosensitive than the R mutant. The occurrence of certain early flowering and flower yielding plants in the latter mutant proved the efficiency of this technique for inducing genetic variability in garden roses. (author)

  19. CHR729 Is a CHD3 Protein That Controls Seedling Development in Rice

    Xiaoding Ma; Jian Ma; Honghong Zhai; Peiyong Xin; Jinfang Chu; Yongli Qiao; Longzhi Han

    2015-01-01

    CHD3 is one of the chromatin-remodeling factors that contribute to controlling the expression of genes associated with plant development. Loss-of-function mutants display morphological and growth defects. However, the molecular mechanisms underlying CHD3 regulation of plant development remain unclear. In this study, a rice CHD3 protein, CHR729, was identified. The corresponding mutant line (t483) exhibited late seed germination, low germination rate, dwarfism, low tiller number, root growth i...

  20. Mitochondrial ORF79 levels determine pollen abortion in cytoplasmic male sterile rice.

    Kazama, Tomohiko; Itabashi, Etsuko; Fujii, Shinya; Nakamura, Takahiro; Toriyama, Kinya

    2016-03-01

    Cytoplasmic male sterility (CMS) is an important agricultural trait characterized by lack of functional pollen, and caused by ectopic and defective mitochondrial gene expression. The pollen function in CMS plants is restored by the presence of nuclear-encoded restorer of fertility (Rf) genes. Previously, we cloned Rf2, which restores the fertility of Lead Rice (LD)-type CMS rice. However, neither the function of Rf2 nor the identity of the mitochondrial gene causing CMS has been determined in LD-CMS rice. Here, we show that the mitochondrial gene orf79 acts as a CMS-associated gene in LD-CMS rice, similar to its role in BT-CMS rice originating from Chinsurah Boro II, and Rf2 weakly restores fertility in BT-CMS rice. We also show that RF2 promotes degradation of atp6-orf79 RNA in a different manner from that of RF1, which is the Rf gene product in BT-CMS rice. The amount of ORF79 protein in LD-CMS rice was one-twentieth of the amount in BT-CMS rice. The difference in ORF79 protein levels probably accounts for the mild and severe pollen defects in LD-CMS and BT-CMS rice, respectively. In the presence of Rf2, accumulation of ORF79 was reduced to almost zero and 25% in LD-CMS and BT-CMS rice, respectively, which probably accounts for the complete and weak fertility restoration abilities of Rf2 in LD-CMS and BT-CMS rice, respectively. These observations indicate that the amount of ORF79 influences the pollen fertility in two strains of rice in which CMS is induced by orf79. PMID:26850149