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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. 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

  5. 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).

  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. 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)

  9. 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.

  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