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Sample records for accumulating rice mutant

  1. Identification of a Long Rice Spikelet Mutant

    WU Xian-jun; WANG Bin; HAN Zan-ping; XIE Zhao-hui; MOU Chun-hong; WANG Xu-dong

    2004-01-01

    A spontaneously occurring rice (Oryza sativa L. ) mutant, characterized by homeotic conversion in glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes and glumaceous lodicules and morphological transformation of stamens into pistils. Mutant florets consisted of 1 to 3 completely developed pistils, some pistilloid stamens with filaments, but tipped by bulged tissue and 0 to 3 stigmas. It seens that the mutant phenotype of the homeotic conversions in glumes and stamens is similar to that of the B loss-of-function mutants in Arabidopsis and Antirrhinum. The mutant is controlled by a single recessive gene as a segregation ratio of 3:1 (wild type to mutant plants) was observed in the F2 generation.

  2. Transporters of arsenite in rice and their role in arsenic accumulation in rice grain.

    Ma, Jian Feng; Yamaji, Naoki; Mitani, Namiki; Xu, Xiao-Yan; Su, Yu-Hong; McGrath, Steve P; Zhao, Fang-Jie

    2008-07-22

    Arsenic poisoning affects millions of people worldwide. Human arsenic intake from rice consumption can be substantial because rice is particularly efficient in assimilating arsenic from paddy soils, although the mechanism has not been elucidated. Here we report that two different types of transporters mediate transport of arsenite, the predominant form of arsenic in paddy soil, from the external medium to the xylem. Transporters belonging to the NIP subfamily of aquaporins in rice are permeable to arsenite but not to arsenate. Mutation in OsNIP2;1 (Lsi1, a silicon influx transporter) significantly decreases arsenite uptake. Furthermore, in the rice mutants defective in the silicon efflux transporter Lsi2, arsenite transport to the xylem and accumulation in shoots and grain decreased greatly. Mutation in Lsi2 had a much greater impact on arsenic accumulation in shoots and grain in field-grown rice than Lsi1. Arsenite transport in rice roots therefore shares the same highly efficient pathway as silicon, which explains why rice is efficient in arsenic accumulation. Our results provide insight into the uptake mechanism of arsenite in rice and strategies for reducing arsenic accumulation in grain for enhanced food safety.

  3. Status and Perspectives on the Researches of Rice Glutelin Mutants

    ZHENG Tian-qing; SHEN Wen-biao; ZHU Su-song; ZHAI Hu-qu; WAN Jian-min

    2003-01-01

    Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising offunctional rice breeding for special usage, glutelin mutants play a more and more important role in the func-tional rice breeding as well as eukaryotic gene expression and regulation research materials. For example, therice cultivar special for the patients suffering from kidney disease and diabetes could be developed from the riceglutelin mutants. In this paper, current researches on characterization, mutation mechanism and breeding us-age of various rice glutelin mutants, especially the low glutelin content cultivars, were all discussed with per-spectives on the trends of the glutelin mutant researches in the era of post-genomics.

  4. Characterization and Fine Mapping of the ibf Mutant in Rice

    Jiajun Cui; Shengci Fan; Tian Shao; Zejun Huang; Dali Zheng; Ding Tang; Ming Li; Qian Qian; Zhukuan Cheng

    2007-01-01

    The pigment is an important character in plant development. In the present study, we characterized and fine mapped one inhibitor for brown furrows gene (ibf) in rice (Oryza sativa L.). in the Ibf mutant, brown pigments specifically accumulate in the furrows of hulls as seeds mature and reach a maximum level in dry seeds. Genetic analysis showed that the mutant phenotype is controlled by one recessive nuclear gene, which was finally mapped in a 90-kb reglon on the long arm of chromosome 9. Polymerase chain reaction and Southern blotting analysis revealed that there was a 26 kb deletion in the 90-kb region in the mutant. Since all the open reading frames outside the gap in the delimited reglon had no detectable difference in DNA sequence with the wild-type, we postulated that the Ibf locus should be located in the gap. Through gene annotation and reverse transcription-polymerase chain reaction (RT-PCR) analysis, we selected OsKF1 encoding a kelch repeat-containing F-box family protein as the candidate gene of ibf.

  5. Preliminary study on a gravity-insensitive rice mutant

    金静; 朱诚; 张红心; 孙宗修

    2004-01-01

    A gravity-insensitive mutant was isolated from rice (Oryza sativa L. Cv. Zhonghua 11) transformed by Agrobacterium tumefaciens. The mutant's shoot growth (prostrate growth) was insensitive to gravity; whereas root growth displayed a normal positive gravitropism.Histological observation of root caps and leaf sheaths indicated that there was no significant difference in the number and size of amyloplasts in cells of the mutant and cells of the wild type

  6. Preliminary study on a gravity-insensitive rice mutant

    金静; 朱诚; 张红心; 孙宗修

    2004-01-01

    A gravity-insensitive mutant was isolated from rice (Oryza sativa L. cv. Zhonghua 11) transformed by Agrobacterium tumefaciens. The mutant's shoot growth (prostrate growth) was insensitive to gravity; whereas root growth displayed a normal positive gravitropism. Histological observation of root caps and leaf sheaths indicated that there was no significant difference in the number and size of amyloplasts in cells of the mutant and cells of the wild type.

  7. Rice mutant resources for gene discovery

    Hirochika, H.; Guiderdoni, E.; An, G.; Hsing, Y.I.; Eun, M.Y.; Han, C.D.; Upadhyaya, N.; Ramachandran, S.; Zhang, Q.F.; Pereira, A.B.; Sundaresan, V.; Leung, H.

    2004-01-01

    With the completion of genomic sequencing of rice, rice has been firmly established as a model organism for both basic and applied research. The next challenge is to uncover the functions of genes predicted by sequence analysis. Considering the amount of effort and the diversity of disciplines requi

  8. 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.

  9. Morphology and inheritance of a new rice leaf death mutant

    CHENGZhakuan; GUMingkang

    1998-01-01

    A new mutant showing successive leaf death was selected in a mutmion populalion from an indica rice variety Zhongxian 3037 trealed with 94Co-γ rays. The leaves of this rnutanl began lodie on the emergence of tlle third leaf tip, and all leaves died sooner alter flowering. Consequently,

  10. 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.

  11. Phenotypic Characterization of a Female Sterile Mutant in Rice

    2006-01-01

    A female sterile mutant, derived from a spontaneous mutation, wasfirst discovered in rice (Oryza sativa L. ssp.indica) restorer line 202R. With normal flowering, the mutant exhibits an extremely Iow seed-setting rate. When the mutant is crossed as a pollen donor, the seeds set normally; whereas when it is used as a pollen receiver,no seeds are obtained even with mixed pollen grains of different varieties sprinkled over the stigmas. The floret of the mutant, consisting of six stamens and one pistil, looks the same as that of the wild type in the malefemale organs, except that less than 10% of the mutant florets have three stigmas on the ovary. Although the mutant has a low seed-setting rate, Its pollen fertility is approximately 87.1%, which is equal to that of the wild type. In addition, more than 90% of the mature embryo sacs of the mutant have complete inner structures. At every stage after pollination, the sperm, embryo, and endosperm are not found in the mutant embryo sac,whereas the disintegration of the egg cell that does not accomplish fertilization is visible. Through observations with a fluorescence microscope, we have found that the pollen grains germinate normally, whereas the pollen tube abnormally elongates in the style-transmitting tissue. The mutant pollen tubes display various defects in the style, such as slower elongation, conversed elongation, distorted elongation, swollen tips, or branched tips. As a result, the growth of the pollen tubes ceases in the style, and, therefore, the pollen tubes cannot reach the embryo sac and the process of double fertilization is blocked. Based on these observations,we conclude that this mutant, designated as fs-202R, is a novel type of female sterile mutation in rice, which causes the arrest of the elongation of the pollen tube.

  12. Thermostability of photosynthesis in two new chlorophyll b-less rice mutants

    LIN; Zhifang; PENG; Changlian; Xu; Xinlan; LIN; Guizhu; ZH

    2005-01-01

    Leaves of the two new chlorophyll b-less rice mutants VG28-1, VG30-5 and the wild type rice cv. Zhonghua 11 were subjected to temperatures 28, 36, 40, 44 and 48℃ in the dark for 30 min or gradually elevated temperature from 30℃ to 80℃ at 0.5℃/min. The thermostability of photosynthetic apparatus was estimated by the changes in chlorophyll fluorescence parameters, photosynthetic rate and pigment content, chloroplast ultrastructure and tissue location of H2O2 accumulation. There were different patterns of Fo-temperature curves between the Chl b-less mutants and the wild type plant, and the temperature of Fo rising threshold was shifted 3℃ lower in the Chl b-less mutants (48℃) than in the wild type (51℃). At temperature up to about 45℃, chloroplasts were swollen and thylakoid grana became misty accompanied with the complete loss of photosynthetic oxygen evolution in the two Chl b-less mutants, but chloroplast ultrastructure in the wild type showed no obvious alteration. After 55℃ exposure, the disordered thylakoid and significant H2O2 accumulation in leaves were found in the two Chl b-less mutants, whereas in the wild type plant, less H2O2 was accumulated and the swollen thylakoid still maintained a certain extent of stacking. A large extent of the changes in qP, NPQ and Fv/Fm was consistent with the Pn decreasing rate in the Chl b-less mutants during high temperature treatment as compared with the wild type. The results indicated that the Chl b-less mutants showed a tendency for higher thermosensitivity, and loss of Chl b in LHC II could lead to less thermostability of PSII structure and function. Heat damage to photosynthetic apparatus might be partially attributed to the internal oxidative stress produced at severely high temperature.

  13. 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.

  14. Serotonin accumulation in transgenic rice by over-expressing tryptophan decarboxylase results in a dark brown phenotype and stunted growth.

    Kanjanaphachoat, Parawee; Wei, Bi-Yin; Lo, Shuen-Fang; Wang, I-Wen; Wang, Chang-Sheng; Yu, Su-May; Yen, Ming-Liang; Chiu, Sheng-Hsien; Lai, Chien-Chen; Chen, Liang-Jwu

    2012-04-01

    A mutant M47286 with a stunted growth, low fertility and dark-brown phenotype was identified from a T-DNA-tagged rice mutant library. This mutant contained a copy of the T-DNA tag inserted at the location where the expression of two putative tryptophan decarboxylase genes, TDC-1 and TDC-3, were activated. Enzymatic assays of both recombinant proteins showed tryptophan decarboxylase activities that converted tryptophan to tryptamine, which could be converted to serotonin by a constitutively expressed tryptamine 5' hydroxylase (T5H) in rice plants. Over-expression of TDC-1 and TDC-3 in transgenic rice recapitulated the stunted growth, darkbrown phenotype and resulted in a low fertility similar to M47286. The degree of stunted growth and dark-brown color was proportional to the expression levels of TDC-1 and TDC-3. The levels of tryptamine and serotonin accumulation in these transgenic rice lines were also directly correlated with the expression levels of TDC-1 and TDC-3. A mass spectrometry assay demonstrated that the darkbrown leaves and hulls in the TDC-overexpressing transgenic rice were caused by the accumulation of serotonin dimer and that the stunted growth and low fertility were also caused by the accumulation of serotonin and serotonin dimer, but not tryptamine. These results represent the first evidence that over-expression of TDC results in stunted growth, low fertility and the accumulation of serotonin, which when converted to serotonin dimer, leads to a dark brown plant color.

  15. Metabolite profiling of two low phytic acid (lpa) rice mutants.

    Frank, Thomas; Meuleye, Bertrand Seumo; Miller, Andreas; Shu, Qing-Yao; Engel, Karl-Heinz

    2007-12-26

    Two low phytic acid (lpa) rice mutant lines, Os-lpa-XS110-1 and Os-lpa-XS110-2, were grown together with their parent wild-type variety Xiushui 110 in four field trials. HPLC analysis of inositol phosphates in the seeds produced demonstrated that compared to the wild-type, the reduction in phytic acid content in Os-lpa-XS110-1 (-46%) was more pronounced than that in Os-lpa-XS110-2 (-23%). Lower inositol phosphates (InsP 3, InsP 4, InsP 5) were not detected in the mutants. The lpa mutants and the wild-type rice were subjected to comparative metabolite profiling by capillary gas chromatography. On average, 34% (Os-lpa-XS110-1) and 42% (Os-lpa-XS110-2) of the detected peaks were statistically significantly different between wild-type and mutants. However, only a few of these differences could be consistently observed for all field trials. Identification and quantification of the consistently different metabolites revealed that contents of myo-inositol and raffinose were increased in Os-lpa-XS110-1 but decreased in Os-lpa-XS110-2 compared to the wild-type. In addition, Os-lpa-XS110-1 exhibited increased levels of galactose and galactinol. Consideration of these metabolic changes in light of the routes involved in the biosynthesis of phytic acid indicated a disturbance in the early biosynthetic pathway of phytic acid in Os-lpa-XS110-2 (similar to the lpa-1 type mutation in maize) and a mutation event affecting phosphorylation of myo-inositol in Os-lpa-XS110-1 (similar to the lpa-3-type mutation).

  16. A wilty mutant of rice has impaired hydraulic conductance.

    Koizumi, Koji; Ookawa, Taiichiro; Satoh, Hikaru; Hirasawa, Tadashi

    2007-08-01

    The rice CM2088 mutant is the wilty phenotype and wilts markedly under well-watered sunny conditions. The leaf water potential and epidermal (mainly stomatal) conductance of CM2088 plants decreased significantly under conditions that induced intense transpiration, as compared with those of wild-type plants, revealing that the wilty phenotype was not the result of abnormal stomatal behavior but was due to an increase in resistance to water transport. The resistance to water transport was dramatically elevated in the node and the sheath and blade of a leaf of the mutant, but not in the root or stem. The diameter of xylem vessels in the large vascular bundles of the leaf sheath and the internode tended to be small, and the numbers of vessel elements with narrowed or scalariform perforation plates in the leaf blade and sheath were greater in the mutant than in the wild type. Most xylem vessels were occluded, with air bubbles in the leaf sheath of the mutant during the midday hours under intense transpiration conditions, while no bubbles were observed in plants that were barely transpiring, revealing that the significant increase in resistance to water transport was a result of the cavitation. The additive effects of cavitation in xylem vessels and the decreased diameter and deformed plates of vessel elements might be responsible for the wilty phenotype of CM2088.

  17. 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:

  18. Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

    ZHEN Xiao-hui; XU Jin-gang; SHEN Wei-jun; ZHANG Xiao-juan; ZHANG Qi-jun; LU Chuan-gen; CHEN Guo-xiang; GAO Zhi-ping

    2014-01-01

    Physiological, biochemical and electron microscopy analyses were used to investigate the photosynthetic performance of flag leaves in rice white stripe mutant 6001 during the senescence process. Results showed that the chlorophyll content at the heading and milk-ripe stages in rice mutant 6001 were about 34.78% and 3.00% less than those in wild type 6028, respectively. However, the chlorophyll content at the fully-ripe stage in rice mutant 6001 was higher than that in wild type 6028. At the heading stage, the net photosynthetic rate (Pn) in rice mutant 6001 was lower than that in wild type 6028. Rice mutant 6001 also exhibited a significantly slower decrease rate ofPn than wild type 6028 during the senescence progress, especially at the later stage. Furthermore, Ca2+-ATPase, Mg2+-ATPase and photophosphorylation activities exhibited the similar trends as thePn. During the senescence process, the 68 kDa polypeptide concentrations in the thylakoid membrane proteins exhibited a significant change, which was one of the critical factors that contributed to the observed change in photosynthesis. We also observed that the chloroplasts of rice mutant 6001 exhibited higher integrity than those of wild type 6028, and the chloroplast membrane of rice mutant 6001 disintegrated more slow during the senescence process. In general, rice mutant 6001 had a relatively slower senescence rate than wild type 6028, and exhibited anti-senescence properties.

  19. GREEN FLUORESCENT PIGMENT ACCUMULATED BY A MUTANT OF CELLVIBRIO GILVUS.

    LOVE, S H; HULCHER, F H

    1964-01-01

    Love, Samuel H. (Bowman Gray School of Medicine, Winston-Salem, N.C.), and Frank H. Hulcher. Green fluorescent pigment accumulated by a mutant of Cellvibrio gilvus. J. Bacteriol. 87:39-45. 1964.-A mutant of Cellvibrio gilvus, designated strain 139A, liberated a green, fluorescent pigment into the surrounding culture medium. A study of the factors which affected the accumulation of this pigment led to the development of a chemically defined medium which supported maximal pigment accumulation in aerated, liquid cultures. d-Glucose, glycine or l-serine, l-phenylalanine, l-proline, and l-lysine comprised the organic components of this medium. The visible absorption spectrum of the pigment showed a maximal band at 400 mmu (pH 7.0). A difference spectrum between reduced and oxidized pigment showed loss of the band at 400 mmu upon oxidation. However, a methanol-extractable, flavinelike compound occurred in the wild strain but not in the mutant. Ferric ions added to the defined medium stimulated growth, with a concomitant reduction of pigment accumulation. Pigment was formed at a maximal rate during the stationary growth phase, and the highest yield was obtained by 18 hr. Organic solvents did not extract the pigment from water solutions. One and sometimes two, compounds absorbing at 400 mmu could be eluted by ion-exchange chromatography on Cellex-P (H(+)), which was used to separate the pigment from other components in the culture supernatants so that the radioactivity of the pigment could be measured. The mutant synthesized C(14)-labeled pigment from d-glucose-U-C(14) and from each of four amino acids (glycine-1-C(14), l-phenylalanine-U-C(14), l-proline-U-C(14), and l-lysine-U-C(14). Delta-Amino-levulenic acid-4-C(14) did not contribute C(14) to the pigment.

  20. Characterization and mapping of a novel light-dependent lesion mimic mutant lmm6 in rice (Oryza sativa L.)

    XIAO Gui-qing; ZHANG Hai-wen; LU Xiang-yang; HUANG Rong-feng

    2015-01-01

    A novel rice lesion mimic mutant (LMM) was isolated from an ethane methyl sulfonate (EMS)-induced 02428 mutant bank. The mutant, tentatively designated as lmm6, develops necrotic lesions in the whole growth period along with changes in several important agronomic traits. We found that the initiation of the lesions was induced by light and cel death occurred in lmm6 accompanied with accumulation of reactive oxygen species (ROS). The lower chlorophyl content, soluble protein content and superoxide dismutase (SOD) activity, the higher malondialdehyde (MDA) content were detected in lmm6 than in the wild type (WT). Moreover, the observation by transmission electronic microscope (TEM) demonstrated that some organel es were damaged and the stroma lamel a of chloroplast was irregular and loose in mesophyl cel of lmm6. In addition, lmm6 was more resistant than WT to rice blast fungus Magnaporthe grisea infection, which was consistent with increased expression of four genes involved in the defense-related reaction. Genetic analysis showed that mutant trait of lmm6 is inherited as a monogenic recessive nuclear gene located on the long arm of chromosome 6. Using simple sequence repeat (SSR) markers, the target gene was ifnal y delimited to an interval of 80.8 kb between markers MM2359 and MM2370, containing 7 annotated genes. Taken together, our results provide the information to identify a new gene involved in rice lesion mimic, which wil be helpful in clarifying the mechanism of cel death and disease resistance in rice.

  1. Plastidic phosphoglucomutase and ADP-glucose pyrophosphorylase mutants impair starch synthesis in rice pollen grains and cause male sterility.

    Lee, Sang-Kyu; Eom, Joon-Seob; Hwang, Seon-Kap; Shin, Dongjin; An, Gynheung; Okita, Thomas W; Jeon, Jong-Seong

    2016-10-01

    To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the plastidic large subunit of ADP-glucose (ADP-Glc) pyrophosphorylase, OsAGPL4 Both genes were up-regulated in maturing pollen, a stage when starch begins to accumulate. Progeny analysis of self-pollinated heterozygous lines carrying the OspPGM mutant alleles, osppgm-1 and osppgm-2, or the OsAGPL4 mutant allele, osagpl4-1, as well as reciprocal crosses between the wild type (WT) and heterozygotes revealed that loss of OspPGM or OsAGPL4 caused male sterility, with the former condition rescued by the introduction of the WT OspPGM gene. While iodine staining and transmission electron microscopy analyses of pollen grains from homozygous osppgm-1 lines produced by anther culture confirmed the starch null phenotype, pollen from homozygous osagpl4 mutant lines, osagpl4-2 and osagpl4-3, generated by the CRISPR/Cas system, accumulated small amounts of starch which were sufficient to produce viable seed. Such osagpl4 mutant pollen, however, was unable to compete against WT pollen successfully, validating the important role of this reserve in fertilization. Our results demonstrate that starch is mainly polymerized from ADP-Glc synthesized from plastidic hexose phosphates in rice pollen and that starch is an essential requirement for successful fertilization in rice.

  2. Difference in Selenium Accumulation in Shoots of Two Rice Cultivars

    ZHANG Lian-He; SHI Wei-Ming; WANG Xiao-Chang

    2006-01-01

    Two japonica rice (Oryza sativa L.) cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain (as high as a three-fold difference), were compared for selenium (Se) accumulation in their shoots when their growth media was supplied with different forms of Se. Results indicated that when treated with 0.25μmol L-1 Na2SeO3,Xiushui 48 accumulation of Se in the shoots was significantly more rapid (P ≤ 0.05) than S. Andrea, probably because of greater Se uptake and transport in Xiushui 48. Xiushui 48 rice seedlings had a higher shoot-Se accumulation rate and absorbed selenocysteine (Se-Cys) more rapidly than S. Andrea seedlings. However, when treated with Se as 0.25 μmol L-1 selenomethionine (Se-Met), the S. Andrea seedlings' accumulation rate was significantly greater (P ≤ 0.05) than that of Xiushui 48. Possibly, the high Se accumulation rate of Xiushui 48 seedling shoots compared to S. Andrea shoots was the result of a higher capacity of Xiushui 48 to transform selenite to organic Se compounds and a higher selenite uptake rate.

  3. Isolation and characterization of a low phytic acid rice mutant reveals a mutation in the rice orthologue of maize mik.

    Using a forward genetics approach, we isolated two independent low phytic acid (lpa) rice mutants, N15-186 and N15-375. Both mutants are caused by single gene, recessive non-lethal mutations which result in approximately 75% (N15-186) and 43% (N15-375) reductions in seed phytic acid (inositol hexaki...

  4. 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.

  5. 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.

  6. Reducing arsenic accumulation in rice grain through iron oxide amendment.

    Farrow, Eric M; Wang, Jianmin; Burken, Joel G; Shi, Honglan; Yan, Wengui; Yang, John; Hua, Bin; Deng, Baolin

    2015-08-01

    Effects of soil-arsenic (As), phosphorus and iron oxide on As accumulation in rice grain were investigated. Cultivars that have significantly different sensitivity to As, straighthead-resistant Zhe 733 and straighthead-susceptible Cocodrie, were used to represent different cultivar varieties. The grain accumulation of other elements of concern, selenium (Se), molybdenum (Mo), and cadmium (Cd) was also monitored. Results demonstrated that high soil-As not only resulted in high grain-As, but could also result in high grain-Se, and Zhe 733 had significantly less grain-As than Cocodrie did. However, soil-As did not impact grain-Mo and Cd. Among all elements monitored, iron oxide amendment significantly reduced grain-As for both cultivars, while the phosphate application only reduced grain-Se for Zhe 733. Results also indicated that cultivar type significantly impacted grain accumulation of all monitored trace elements. Therefore, applying iron oxide to As-contaminated land, in addition to choosing appropriate rice cultivar, can effectively reduce the grain accumulation of As.

  7. Accumulation and toxicological response of atrazine in rice crops.

    Zhang, Jia Jun; Lu, Yi Chen; Zhang, Jin Jin; Tan, Li Rong; Yang, Hong

    2014-04-01

    Atrazine is one of the most widely used herbicides for controlling weeds and grasses. Due to its intensive use, it has become a serious contaminant in soil and water. To evaluate impact of atrazine on graminaceous crops, experiments focusing on atrazine accumulation and toxic response in rice (Oryza sativa) were carried out. Treatment with atrazine at 0.05-0.8 mg L(-1) for 6 d reduced elongation of shoot and root. Compared with a mock treatment, the elongation of shoot with atrazine was 67.1 percent of the control, whereas that of root was 79.5 percent, indicating that the shoot was more affected than the root. Atrazine was readily absorbed by rice from media. Although the quantitative absorption of atrazine was positively correlated with the external supply of the herbicide, translocation of atrazine from roots to the above-ground was reduced from 39.88±6.26 (at 0.05 mg L(-1)) to 9.25±0.27 (0.8 mg L(-1)). While accumulation of atrazine in rice plants led to toxic responses such as over-generation of hydrogen peroxide and superoxide anions, it triggered the plant defense system against the herbicide-induced oxidative stress. This was best presented by the enhanced activities of several antioxidant enzymes (e.g. superoxide dismutase, catalase and peroxidase) and expression of genes responsible for the tolerance to atrazine toxicity.

  8. A rice ABC transporter, OsABCC1, reduces arsenic accumulation in the grain

    Song, Won-Yong; Yamaki, Tomohiro; Yamaji, Naoki; Ko, Donghwi; Jung, Ki-Hong; Fujii-Kashino, Miho; An, Gynheung; Martinoia, Enrico; Lee, Youngsook; Ma, Jian Feng

    2014-01-01

    Arsenic (As) is a chronic poison that causes severe skin lesions and cancer. Rice (Oryza sativa L.) is a major dietary source of As; therefore, reducing As accumulation in the rice grain and thereby diminishing the amount of As that enters the food chain is of critical importance. Here, we report that a member of the Oryza sativa C-type ATP-binding cassette (ABC) transporter (OsABCC) family, OsABCC1, is involved in the detoxification and reduction of As in rice grains. We found that OsABCC1 was expressed in many organs, including the roots, leaves, nodes, peduncle, and rachis. Expression was not affected when plants were exposed to low levels of As but was up-regulated in response to high levels of As. In both the basal nodes and upper nodes, which are connected to the panicle, OsABCC1 was localized to the phloem region of vascular bundles. Furthermore, OsABCC1 was localized to the tonoplast and conferred phytochelatin-dependent As resistance in yeast. Knockout of OsABCC1 in rice resulted in decreased tolerance to As, but did not affect cadmium toxicity. At the reproductive growth stage, the As content was higher in the nodes and in other tissues of wild-type rice than in those of OsABCC1 knockout mutants, but was significantly lower in the grain. Taken together, our results indicate that OsABCC1 limits As transport to the grains by sequestering As in the vacuoles of the phloem companion cells of the nodes in rice. PMID:25331872

  9. Molecular mapping of split rice spikelet mutant srs-1 and analysis of its homeotic function in rice

    2000-01-01

    srs-1, a new floral organ identity gene in rice, was mapped using RAPD and RFLP markers. Firstly, the cross was made between "ZhaiYeQing 8" (ZYQ8, indica) and split rice spikelet (SRS, japonica) mutant. The ratio of wild-type individuals and mutant plants in F2 population is 3:1, which indicates that the mutant characteristics are controlled by single recessive gene, srs-1. Consequently, BSA method was adopted and 520 random 10-mer primers were used to screen polymorphic bands between two bulks. Six primers could amplify polymorphic bands, of which S465 generates the most stable RAPD patterns. Then, S465 that cosegregates in F2 population has been converted into an RFLP marker successfully. Furthermore, srs-1 gene was mapped on chromosome 3 using DH mapping population. The effect of srs-1 gene results in the mutant of split rice spikelet. The mutant has longer and softer palea/lemma than those of wild-type, and two small palea/lemma-like organs between palea and lemma. In addition, there is a flower with three stamens and carpel in the axil of lemma. Thus, there are nine stamens and two carpels in the spikelet of mutant. srs-1 gene may belong to homeotic gene of class A according to the mutant characteristics and ABC model.

  10. 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.

  11. 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.

  12. Using iron fertilizer to control Cd accumulation in rice plants: a new promising technology.

    Shao, GuoSheng; Chen, MingXue; Wang, DanYing; Xu, ChunMei; Mou, RenXiang; Cao, ZhaoYun; Zhang, XiuFu

    2008-03-01

    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 concentration 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 concentration 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.

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

    SHAO GuoSheng; CHEN MingXue; WANG DanYing; XU ChunMei; MOU RenXiang; CAO ZhaoYun; ZHANG XiuFu

    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.Na=Fe 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 concentration 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 concentration 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.

  14. Isolation and characterization of rice lesion mimic mutants from a T-DNA tagged population

    LI Shutian; PEI Zhongyou; LUO Lijuan; TIAN Yingchuan; HE Chaozu

    2005-01-01

    A rice ( Oryza sativa L. ssp. japonica cv. Nipponbare) T-DNA tagged population consisting of about 7000 individual lines was generated and screened for rice lesion mimic mutants in the T1 generation. Ten lines were found to develop spontaneous lesions in the absence of pathogen infection and displayed distinct lesion phenotypes. These mutants were tentatively designated as lm1 -lm10 (for lesion mimic), respectively. Lesion formation of lm mutants was developmentally regulated, and all the mutants showed stunted growth and reduced fertility. Genetic analysis demonstrated that all the mutations were recessive, and five partially fertile mutants (lm4-lm8) were derived from different loci. Mimic lesions occurring on the leaves of lm mutants resulted from cell death as revealed by trypan blue staining. Six of them ( lm3 -lm8 ) exhibited enhanced resistance to five bacterial blight isolates, indicating their wide-spectrum resistance to this pathogen. These results imply that some lesion mimic mutations of rice might be involved in disease resistance signaling pathways,and that isolation of these mutated genes may be useful for elucidating molecular mechanisms of plant disease resistance. Among the mutants, only one mutant, lm6, was preliminarily shown to cosegregate with the inserted T-DNA in its T1 generation, making it feasible to isolate the gene responsible for the phenotype of this mutant.

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

    Meng, Mei; Li, Bing; Shao, Jun-juan; Wang, Thanh; He, Bin; Shi, Jian-bo; Ye, Zhi-hong; Jiang, Gui-bin

    2014-01-01

    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 & 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.

  16. 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.

  17. Effects of Rice Yield and Quality Across Accumulated Temperature Zone Planting in Cold Area

    Wang Qiu-ju; Liu Feng; Gao Pan; Gao Zhong-chao; Chang Ben-chao; Liu Yan-xia; Zhang Li-li

    2015-01-01

    Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains per panicle and percentage of head-milled rice displayed quadratic curves against the accumulated temperature, and the sterile rate decreased with greater accumulated temperature. However, 1 000-grain weight had no correlation with the accumulated temperature and protein content, amylose content and taste also had no obvious relation with the accumulated temperature. The results from the accumulated temperature differed with rice variety, so the temperature insensitive type variety should be proposed for production.

  18. Molecular mapping of split rice spikelet mutant srs-1 and analysis of its homeotic function in rice

    白素兰; 刘永胜; 孙敬三; 朱立煌

    2000-01-01

    srs-1, a new floral organ identity gene in rice, was mapped using RAPD and RFLP markers. Firstly, the cross was made between "ZhaiYeQing 8" (ZYQ8, indica) and split rice spikelet (SRS, japonica) mutant. The ratio of wild-type individuals and mutant plants in F2 population is 3:1, which indicates that the mutant characteristics are controlled by single recessive gene, srs-1. Consequently, BSA method was adopted and 520 random 10-mer primers were used to screen polymorphic bands between two bulks. Six primers could amplify polymorphic bands, of which S465 generates the most stable RAPD patterns. Then, S465 that cosegregates in F2 population has been converted into an RFLP marker successfully. Furthermore, srs-1 gene was mapped on chromosome 3 using DH mapping population. The effect of srs-1 gene results in the mutant of split rice spikelet. The mutant has longer and softer palea/lemma than those of wild-type, and two small palea/lemma-like organs between palea and lemma. In addition, there is a flower wit

  19. 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.

  20. 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.

  1. Alterations in DNA methylation and genome structure in two rice mutant lines induced by high pressure

    SHEN; Sile; WANG; Zhenwei; SHAN; Xiaohui; WANG; Hua; LI; Ling; LIN; Xuyun; LONG; Likun; WENG; Kenan; LIU; Bao; ZOU; Guangtian

    2006-01-01

    By using high-pressure treatment, two mutant lines were obtained from a genetically stable japonica rice cultivar Bijing38. Genomic DNA of the mutant lines, together with the original line (Bijing38), was either undigested or digested by Hpa II/Msp I, and then subjected to molecular analysis using two markers, ISSR and RAPD. Results indicated that changes in the PCR amplification profiles of both markers are apparent in the two mutant lines compared with the original rice cultivar, suggesting that there had been both sequence changes and DNA methylation modifications in the mutant lines. Southern blot analysis using diverse sequences, including two cellular genes (S2 and S3), a set of retrotransposons (Osr7, Osr36, Tos19 and more), and a MITE transposon family (mPing and Pong), confirmed the results, and indicated that changes in DNA methylation pattern, genomic structure, and possible activation of some transposons indeed occurred in the mutant lines. Moreover, these changes are stably maintained through selfed generations and in different organs. Thus, our results indicate that it is possible to obtain stable mutants in rice by high pressure treatments, and the molecular basis of the mutants may include both genetic and epigenetic changes. Therefore, high hydrostatic pressure seems a promising approach for plant mutagenesis.

  2. Induction of serotonin accumulation by feeding of rice striped stem borer in rice leaves.

    Ishihara, Atsushi; Hashimoto, Yumi; Miyagawa, Hisashi; Wakasa, Kyo

    2008-09-01

    Tryptophan (Trp)-related secondary metabolism has been implicated in the defense against pathogen infection and insect feeding in various gramineous species. Recently, we also reported that rice plant accumulated serotonin and tryptamine as well as their amide compounds coupled with phenolic acids in response to the infection by fungal pathogen. These compounds were likely to play an important role in the formation of physical barrier to the invading pathogens. To extend our study to elucidate the defensive role of Trp-derived secondary metabolism in gramineous plants, we examined in this study whether it is activated in response to herbivore attack as well. Third leaves of rice plant were fed on by third instar larvae of rice striped stem borer for 24 h or 48 h. The analysis of four Trp-derived metabolites including tryptamine, serotonin feruloyltryptamine (FerTry) and p-coumaroylserotonin (CouSer) by liquid chromatography coupled with tandem mass spectrometry revealed that their contents clearly increased in response to the larvae feeding. The respective amounts of tryptamine, serotonin, FerTry and CouSer in the larvae-fed leaves were 12-, 3.5-, 33- and 140-fold larger than those in control leaves 48 h after the start of feeding.

  3. Physiological basis and transcriptional profiling of three salt-tolerant mutant lines of rice

    Concha Domingo

    2016-09-01

    Full Text Available Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62 and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of

  4. Physiological Basis and Transcriptional Profiling of Three Salt-Tolerant Mutant Lines of Rice

    Domingo, Concha; Lalanne, Eric; Catalá, María M.; Pla, Eva; Reig-Valiente, Juan L.; Talón, Manuel

    2016-01-01

    Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62, and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of these salt

  5. 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.

  6. 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.

  7. Effects of Three Inhibitors on the Accumulation of Cadmium in Rice (Oryza sativa L.)

    LONG Si-si; Yang, Yi-Xin; SONG Zheng-guo; Lei, Ming; Yong YANG; Yu, Li

    2016-01-01

    How to control cadmium (Cd) pollution in rice grain has become a hot research issue. The effects of the three amendments such as lime, silicon fertilizer and zinc foliar fertilizer from local market on the accumulation Cd in rice grain including early rice and later rice growth in one Cd-contaminated field in Hengyang County, Hunan Province were studied. Among the three treatments, the silicon fertilizer and lime were applied into soil, and the zinc fertilizer was sprayed on the leaf of rice ...

  8. 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.

  9. 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).

  10. Effect of Low Content Chlorophyll on Distribution Properties of Absorbed Light Energy in Leaves of Mutant Rice

    XU Xiao-ming; ZHANG Rong-xian; TANG Yun-lai

    2004-01-01

    This paper reported the diurnal variations of photochemical efficiency of PSII, thermal dissipation rate and other physiology process in thelow content chlorophyll mutant rice and its wild type under field conditions, and analyzed the difference of absorbed light distribution between the two rice varieties in a day. The results showed that the mutant had poor absorbed light because of its little light absorption coefficient, but higher electron transportg rate could partly reduce the disadvantageous effect of deficient absorbed light in mutant. Compared with wild-type rice, the mutant had less excess excitation energy and the fraction of absorbed light allocated to photochemical process was more.

  11. A Rapid DNA Mini-prep Method for Large-Scale Rice Mutant Screening

    QIU Fu-lin; WANG He-he; CHEN Jie; ZHUANG Jie-yun; Hei LEUNG; CHENG Shi-hua; Wu Jian-li

    2006-01-01

    A high throughput rice DNA mini-preparation method was developed. The method is suitable for large-scale mutant bank screening as well as large mapping populations with characteristics of maintaining relatively high level of DNA purity and concentration. The extracted DNA was tested and suitable for regular PCR amplification (SSR) and for Targeting Induced Local Lesion in Genome (TILLING) analysis.

  12. Morphological Structure and Genetic Mapping of New Leaf-Color Mutant Gene in Rice (Oryza sativa)

    LI Yu-hong; WANG Bao-he; DAI Zheng-yuan; LI Ai-hong; LIU Guang-qing; ZUO Shi-min; ZHANG Hong-xi; PAN Xue-biao

    2012-01-01

    Leaf-color mutations are a widely-observed class of mutations,playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure,function,genetics and development.A naturally-occurring leaf-color rice mutant,Baihuaidao 7,was analyzed.Mutant plants typically exhibited a green-white-green leaf-color progression,but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation.Prior to the appearance of white leaves,mutant plant growth,leaf color,chlorophyll content,and chloroplast ultrastructure appeared to be identical to those of the wild type.After the changeover to white leaf color,an examination of the mutated leaves revealed a decrease in total chlorophyll,chlorophyll a,chlorophyll b,and carotenoid content,a reduction in the number of chloroplast grana lamella and grana,and a gradual degradation of the thylakoid lamellas.At maturity,the mutant plant was etiolated and dwarfed compared with wild-type plants.Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene.Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ×Jiangxi 1587 cross.The mutant gene was mapped to rice chromosome 11,positioned between InDel markers L59.2-7 and L64.8-11,which are separated by approximately 740.5 kb.The mutant gene is believed to be a new leaf-color mutant gene in rice,and is tentatively designated as gwgl.

  13. Effect of external and internal phosphate status on arsenic toxicity and accumulation in rice seedlings

    WANG Lihong; DUAN Guilan

    2009-01-01

    Phosphorus (P) deficiency is thought to exacerbate the arsenic (As) phytotoxicity in paddy rice. Therefore, experiments were conducted to investigate the effects of external phosphate supply on As accumulation in and toxicity to rice plants under phosphate deficiency conditions. Rice seedlings being pretreated with -P (phosphorus deficiency) nutrient solution for 14 d accumulated more As than those pretreated with +P (normal phosphorus supply) nutrient solution. -P pretreated rice showed As toxicity symptoms after being exposed to 50 μmol/L arsenate for 4 h, while +P rice did not show any toxicity symptoms. Arsenic toxicity symptoms can be alleviated with increasing of external P concentrations. Arsenate uptake rate and accumulation corresponded with As toxicity in rice plants. Arsenic concentrations in rice roots decreased with increasing external phosphate concentrations. The lowest As accumulation and the highest P accumulation were found when the external P concentration reached 100 μmol/L. In a summary, P deficiency increased the sensitivity of rice to arsenate and increasing of external phosphate supply could alleviate As toxicity.

  14. Effects of Three Inhibitors on the Accumulation of Cadmium in Rice (Oryza sativa L.

    LONG Si-si

    2016-09-01

    Full Text Available How to control cadmium (Cd pollution in rice grain has become a hot research issue. The effects of the three amendments such as lime, silicon fertilizer and zinc foliar fertilizer from local market on the accumulation Cd in rice grain including early rice and later rice growth in one Cd-contaminated field in Hengyang County, Hunan Province were studied. Among the three treatments, the silicon fertilizer and lime were applied into soil, and the zinc fertilizer was sprayed on the leaf of rice plant. The results showed that, except lime and zinc fertilizer(late rice, in comparison to nonamendment, the output of early rice and late rice increased with increasing of the other types of resistances. Among three kinds of resistances, the zinc foliar fertilizer had significant impacts on decreasing Cd in edible grains, in which Cd concentrations of early rice(Y-liangyou 792 and late rice(Nongxiang130 reduced by 51.28% and 50.92%, respectively, followed by silicon fertilizer. The present study demonstrated that the silicon fertilizer and zinc foliar fertilizer would be used as resistances for remediation Cd-polluted rice plant, moreover, the relationship between Zn and Cd in rice-soil would need further studied.

  15. 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.

  16. Genetic Analysis and Mapping of TWH Gene in Rice Twisted Hull Mutant

    LI Jin-bo; XIA Ming-yuan; WAN Bing-liang; DU Xue-shu; ZHA Zhong-ping; YU Da-zhao; QI Hua-xiong

    2009-01-01

    A mutant with twisted hulls was found in a breeding population of rice (Oryza sativa L.). The mutant shows less grain weight and inferior grain quality in addition to twisted hulls. Genetic analysis indicated that the phenotype of mutant was controlled by a single recessive gene (temporarily designated as TWH). To map the TWH gene, an F2 population was generated by crossing the twh mutant to R725, an indica rice variety with normal hulls. For bulked segregant analysis, the bulk of mutant plants was prepared by mixing equal amount of plant tissue from 10 twisted-hull plants and the bulk of normal plants was obtained by pooling equal amount tissue of 10 normal-hull plants. Two hundred and seven pairs of simple sequence repeat (SSR) primers, which are distributed on 12 rice chromosomes, were used for polymorphism analysis of the parents and the two bulks. The TWH locus was initially mapped close to the SSR marker RM526 on chromosome 2. Therefore, further mapping was performed using 50 pairs of SSR primers around the marker RM526. The TWH was delimited between the SSR markers RM14128 and RM208 on the long arm of chromosome 2 at the genetic distances of 1.4 cM and 2.7 cM, respectively. These results provide the foundation for further fine mapping, cloning and functional analysis of the TWH gene.

  17. 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.

  18. Potassium accumulation and translocation among rice genotypes in relation to internal potassium use efficiency (IKUE)

    2001-01-01

    @@ Abiotic stresses including potassium deficiency are limiting factors for increasing rice yield. Nine rice genotypes (Oryza Sativa L., indica) differing in sensitivity to low K stress selected from 200 volume-solution screening were used in this study to examine accumulation and translocation of K.

  19. The TOC159 mutant of Arabidopsis thaliana accumulates altered levels of saturated and polyunsaturated fatty acids.

    Afitlhile, Meshack; Fry, Morgan; Workman, Samantha

    2015-02-01

    We evaluated whether the TOC159 mutant of Arabidopsis called plastid protein import 2-2 (ppi2-2) accumulates normal levels of fatty acids, and transcripts of fatty acid desaturases and galactolipid synthesis enzymes. The ppi2-2 mutant accumulates decreased pigments and total fatty acid content. The MGD1 gene was downregulated and the mutant accumulates decreased levels of monogalactosyldiacylglycerol (MGDG) and 16:3, which suggests that the prokaryotic pathway was impaired in the mutant. The HY5 gene, which encodes long hypocotyl5 transcription factor, was upregulated in the mutant. The DGD1 gene, an HY5 target was marginally increased and the mutant accumulates digalactosyldiacylglycerol at the control level. The mutant had increased expression of 3-ketoacyl-ACP synthase II gene, which encodes a plastid enzyme that elongates 16:0 to 18:0. Interestingly, glycerolipids in the mutant accumulate increased levels of 18:0. A gene that encodes stearoyl-ACP desaturase (SAD) was expressed at the control level and 18:1 was increased, which suggest that SAD may be strongly regulated at the posttranscriptional level. The molar ratio of MGDG to bilayer forming plastid lipids was decreased in the cold-acclimated wild type but not in the ppi2-2 mutant. This indicates that the mutant was unresponsive to cold-stress, and is consistent with increased levels of 18:0, and decreased 16:3 and 18:3 in the ppi2-2 mutant. Overall, these data indicate that a defective Toc159 receptor impaired the synthesis of MGDG, and affected desaturation of 16 and 18-carbon fatty acids. We conclude that expression of the MGD1 gene and synthesis of MGDG are tightly linked to plastid biogenesis.

  20. Cadmium accumulation in different rice cultivars and screening for pollution-safe cultivars of rice

    Yu Hui [State Key Laboratory for Biocontrol, also School of Life Sciences, Sun Yat-sen University, Guangzhou 510275 (China); Wang Junli [State Key Laboratory for Biocontrol, also School of Life Sciences, Sun Yat-sen University, Guangzhou 510275 (China); Fang Wei [Biology Department, Long Island University, Brooklyn, NY 11201 (United States); Yuan Jiangang [State Key Laboratory for Biocontrol, also School of Life Sciences, Sun Yat-sen University, Guangzhou 510275 (China); Yang Zhongyi [State Key Laboratory for Biocontrol, also School of Life Sciences, Sun Yat-sen University, Guangzhou 510275 (China)]. E-mail: adsyzy@mail.sysu.edu.cn

    2006-11-01

    Large areas of contaminated land are being used for agricultural production in some countries due to the high demand for food. To minimize the influx of pollutants to the human food chain through consumption of agricultural products, we propose the concept of pollution-safe cultivars (PSCs), i.e. cultivars whose edible parts accumulate a specific pollutant at a level low enough for safe consumption, even when grown in contaminated soil. We tested the feasibility of the PSC concept by growing 43 cultivars of paddy rice (Oryza sativa L., including 20 normal and 23 hybrid cultivars) under a high (75.69-77.55 mg kg{sup -1}) and a low (1.75-1.85 mg kg{sup -1}) cadmium (Cd) exposure. These pot experiments took place in the spring and summer of 2004. At the low level of Cd exposure, 30 out of the 43 tested cultivars were found to be Cd-PSCs. Grain Cd concentrations were highly correlated (p < 0.01) between the two experiments, suggesting that Cd accumulation in rice grain is genotype-dependent and that the selection of PSCs is possible, at least at a certain level of soil contamination. No Cd-PSCs were found under the high level of Cd exposure. Yield was enhanced in some cultivars and depressed in others in response to elevated soil Cd, indicating that farmers cannot rely on yield depression as an indicator of toxicity of the grains. It is therefore important and feasible to screen for PSCs and to establish PSC breeding programs to effectively and efficiently reduce the risk of human exposure to soil pollutants, such as Cd, through crop consumption.

  1. Manganese accumulation in rice: implications for photosynthetic functioning.

    Lidon, Fernando Cebola; Barreiro, Maria Graça; Ramalho, José Cochicho

    2004-11-01

    In order to gain fundamental insights into the nature of the adaptation to Mn excess, the characterisation of the photosynthetic apparatus in Mn-treated rice was carried out in 21-day-old plants. We found 17- and 11-fold increases in Mn in the leaf tissues and in thylakoid, respectively, when the plants were grown hydroponically in nutrient solutions with Mn concentrations between 0.125 and 32 mg l(-1) (2.3 and 582.5 microM). Net photosynthesis and the photosynthetic capacity decreased after the 0.5 and 2 mg l(-1) (9.1 and 36.4 microM) Mn treatment, respectively. The stomatal conductance displayed a similar trend to that of photosynthetic capacity. The levels of basal chlorophyll fluorescence and the ratio between variable and maximum chlorophyll fluorescence did not vary significantly among treatments, but the photochemical quenching and the quantum yield of non-cyclic electron transport increased until the 2 mg l(-1) (36.4 microM) Mn treatment. The lipid matrix of thylakoids revealed a global increase in the proportions of phospholipids, relative to galactolipids. This pattern was coupled with diminishing levels of monogalactosyldiacylglycerol. The relative ratio between total carotenoids and total chlorophylls decreased until the last Mn treatment, yet the levels of carotenes, zeaxanthin, and violaxanthin plus antheraxanthin displayed different patterns. It was further found that the de-epoxidation state involving the components of the xanthophylls cycle increased until the 8 mg l(-1) (145.6 microM) Mn treatment. The levels of the photosynthetic electron carriers displayed different patterns, with plastocyanin and the high and low forms of cytochrome b559 remaining steady, whereas cytochromes b563 and f increased until the 8 mg l(-1) (145.6 microM) Mn treatment and the quinone pool increased until the highest Mn treatment. It was concluded that Mn-mediated inhibition of rice photosynthesis barely implicates stomatal conductance, as well as the distribution of

  2. 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.

  3. Effect of Biochar on Relieving Cadmium Stress and Reducing Accumulation in Super japonica Rice

    ZHANG Zhen-yu; MENG Jun; DANG Shu; CHEN Wen-fu

    2014-01-01

    It is of great importance to solve the threats induced by cadmium pollution on crops. This paper examined the effect of biochar on cadmium accumulation in japonica rice and revealed the mechanism underlying the response of protective enzyme system to cadmium stress. Biochar derived from rice straw was applied at two application rates under three cadmium concentrations. Shennong 265, super japonica rice variety, was selected as the test crop. The results indicated that cadmium content in above-ground biomass of rice increased with increasing soil cadmium concentrations, but the biochar application could suppress the accumulation of cadmium to some extent. Under high concentrations of cadmium, content of free proline and MDA (malondialdehyde) were high, so did the SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase) activity in the lfag leaf of rice. However, the protective enzyme activities remained at low level when biochar was added.

  4. Impact of agronomic practices on arsenic accumulation and speciation in rice grain.

    Ma, Rui; Shen, Jianlin; Wu, Jinshui; Tang, Zhong; Shen, Qirong; Zhao, Fang-Jie

    2014-11-01

    Rice is a major source of dietary arsenic (As). The effects of paddy water management, straw incorporation, the applications of nitrogen fertilizer or organic manure, and the additions of biochar on arsenic accumulation and speciation in rice grain were investigated under field conditions over four cropping seasons in Hunan, China. Treatments that promoted anaerobic conditions in the soil, including continuous flooding and straw incorporation, significantly increased the concentration of As, especially methylated As species, in rice grain, whereas N application rate and biochar additions had little or inconsistent effect. Continuous flooding and straw incorporation also increased the abundance of the arsenite methyltransferase gene arsM in the soil, potentially enhancing As methylation in the soil and the uptake of methylated As by rice plants. Intermittent flooding was an effective method to decrease As accumulation in rice grain.

  5. Differential gene expression in salt-tolerant rice mutant and its parental variety

    张劲松; 周骏马; 张驰; 陈受宜

    1996-01-01

    The differential expressions of three genes rbcL, salT and rab!6 in response to ABA, NaCl, PEG and heat shock were investigated in seedlings of a salt-tolerant rice mutant 20 (mutant 20) and its parental variety Oryza sativa var. japonica 77-170(170). By Northern blot analysis it was found that ABA induced the expression of all three genes of rbcL, salT and rab16 in shoots and roots of both 170 and mutant 20 with the exceptions of rab16 in shoots of mutant 20 and rbcL in roots of 170. Lower concentrations of NaCl induced rbcL expression in shoots of mutant 20 but not 170. Higher concentrations of NaCl decreased rbcL expression but induced expressions of salT and rab16 in shoots of both 170 and mutant 20. PEG(15%) and 37℃ heat shock showed almost no effects on the expression of the three genes in mutant 20. However, they caused a decrease in rbcL expression and slight induction of the rab16 gene in 170, with salT expression unaffected. These results indicated that mutant 20 was relatively less responsiv

  6. Widespread nuclear and cytoplasmic accumulation of mutant androgen receptor in SBMA patients.

    Adachi, Hiroaki; Katsuno, Masahisa; Minamiyama, Makoto; Waza, Masahiro; Sang, Chen; Nakagomi, Yuji; Kobayashi, Yasushi; Tanaka, Fumiaki; Doyu, Manabu; Inukai, Akira; Yoshida, Mari; Hashizume, Yoshio; Sobue, Gen

    2005-03-01

    Spinal and bulbar muscular atrophy (SBMA) is an inherited adult onset motor neuron disease caused by the expansion of a polyglutamine (polyQ) tract within the androgen receptor (AR), affecting only males. The characteristic pathological finding is nuclear inclusions (NIs) consisting of mutant AR with an expanded polyQ in residual motor neurons, and in certain visceral organs. We immunohistochemically examined 11 SBMA patients at autopsy with 1C2, an antibody that specifically recognizes expanded polyQ. Our study demonstrated that diffuse nuclear accumulation of mutant AR was far more frequent and extensive than NIs being distributed in a wide array of CNS nuclei, and in more visceral organs than thus far believed. Mutant AR accumulation was also present in the cytoplasm, particularly in the Golgi apparatus; nuclear or cytoplasmic predominance of accumulation was tissue specific. Furthermore, the extent of diffuse nuclear accumulation of mutant AR in motor and sensory neurons of the spinal cord was closely related to CAG repeat length. Thus, diffuse nuclear accumulation of mutant AR apparently is a cardinal pathogenetic process underlying neurological manifestations, as in SBMA transgenic mice, while cytoplasmic accumulation may also contribute to SBMA pathophysiology.

  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. Phenotypic analysis and molecular characterization of an allelic mutant of the D61 gene in rice

    Yanan Gao

    2014-08-01

    Full Text Available Brassinosteroids (BRs are a class of plant-specific steroidal hormones that play important roles in multiple biological processes. In this paper, a classic rice mutant gsor300084, showing erect leaves and semi-dwarf stature, was characterized. Morphological analysis in darkness showed that the mesocotyl of the gsor300084 mutant did not elongate when grown in darkness. Coleoptile elongation and root growth were less affected by the exogenous application of brassinolide (BL, the most active form of BR, in gsor300084 than in the wild-type rice variety Matsumae. Lamina joint bending analysis also showed that gsor300084 was less sensitive to exogenous BL than Matsumae. These results suggested that the gsor300084 mutant is defective in BR sensitivity. Map-based cloning indicated that gsor300084 is a novel allelic mutant of the DWARF61 (D61 gene, which encodes the putative BR receptor OsBRI1. A single-base mutation appears in the LRR domain of OsBRI1, changing the 444th amino acid from tryptophan (W to arginine (R. Subcellular localization analysis suggested that both the wild-type and mutant OsBRI1 protein are localized at the cytoplasmic membrane. Structure modeling revealed that the W444R substitution may affect the perception of BRs by the LRR domain.

  9. Phenotypic analysis and molecular characterization of an allelic mutant of the D61 gene in rice

    Yanan; Gao; Guangquan; Wang; Shoujiang; Yuan; Yanling; Qin; Jinfeng; Zhao; Yanpei; Zhang; Wenhui; Zhang; Xueyong; Li

    2014-01-01

    Brassinosteroids(BRs) are a class of plant-specific steroidal hormones that play important roles in multiple biological processes. In this paper, a classic rice mutant gsor300084,showing erect leaves and semi-dwarf stature, was characterized. Morphological analysis in darkness showed that the mesocotyl of the gsor300084 mutant did not elongate when grown in darkness. Coleoptile elongation and root growth were less affected by the exogenous application of brassinolide(BL), the most active form of BR, in gsor300084 than in the wild-type rice variety Matsumae. Lamina joint bending analysis also showed that gsor300084 was less sensitive to exogenous BL than Matsumae. These results suggested that the gsor300084 mutant is defective in BR sensitivity. Map-based cloning indicated that gsor300084 is a novel allelic mutant of the DWARF61(D61) gene, which encodes the putative BR receptor OsBRI1. A single-base mutation appears in the LRR domain of OsBRI1, changing the 444 th amino acid from tryptophan(W) to arginine(R). Subcellular localization analysis suggested that both the wild-type and mutant OsBRI1 protein are localized at the cytoplasmic membrane. Structure modeling revealed that the W444 R substitution may affect the perception of BRs by the LRR domain.

  10. 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.

  11. 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.

  12. Accumulation of Flavonoids in an ntra ntrb Mutant Leads to Tolerance to UV-C

    Talaat Bashandy; Ludivine Taconnat; Jean-Pierre Renou; Yves Meyer; Jean-Philippe Reichheld

    2009-01-01

    NADPH-dependent thioredoxin reductases (NTRs) are key regulatory enzymes determining the redox state of thioredoxins. There are two genes encoding NTRs (NTRA and NTRB) in the Arabidopsis genome, each encoding a cytosolic and a mitochondrial isoform. A double ntra ntrb mutant has recently been characterized and shows slower plant growth, slightly wrinkled seeds and a remarkable hypersensitivity to buthionine sulfoximine (BSO), a specific inhibitor of gluta-thione biosynthesis. In this paper, we demonstrate that this mutant also accumulates higher level of flavonoids. Analysis of transcriptome data showed that several genes of the flavonoid pathway are overexpressed in the ntra ntrb mutant. Accumulation of flavonoids is generally considered a hallmark of plant stress. Nevertheless, no elevation of the expression of genes encoding ROS-detoxification enzymes was observed, suggesting that the ntra ntrb plants do not suffer from oxidative disease. Another hypothesis suggests that flavonoids are specifically synthesized in the ntra ntrb mutant in order to rescue the inactivation of NTR. To test this, the ntra ntrb mutant was crossed with transparent testa 4 (tt4) plants with a mutation in the gene encoding the first enzyme in flavonoid biosynthesis. As ntra ntrb plants are more resistant to UV-C treatment than wild-type plants, this higher resistance was abolished in the ntra ntrb tt4 mutant, suggesting that accumulation of flavonoids in the ntra ntrb mutant protects plants against UV-light.

  13. Overexpression of rice glutaredoxins (OsGrxs) significantly reduces arsenite accumulation by maintaining glutathione pool and modulating aquaporins in yeast.

    Verma, Pankaj Kumar; Verma, Shikha; Meher, Alok Kumar; Pande, Veena; Mallick, Shekhar; Bansiwal, Amit Kumar; Tripathi, Rudra Deo; Dhankher, Om Parkash; Chakrabarty, Debasis

    2016-09-01

    Arsenic (As) is an acute poison and class I carcinogen, can cause a serious health risk. Staple crops like rice are the primary source of As contamination in human food. Rice grown on As contaminated areas accumulates higher As in their edible parts. Based on our previous transcriptome data, two rice glutaredoxins (OsGrx_C7 and OsGrx_C2.1) were identified that showed up-regulated expression during As stress. Here, we report OsGrx_C7 and OsGrx_C2.1 from rice involved in the regulation of intracellular arsenite (AsIII). To elucidate the mechanism of OsGrx mediated As tolerance, both OsGrxs were cloned and expressed in Escherichia coli (Δars) and Saccharomyces cerevisiae mutant strains (Δycf1, Δacr3). The expression of OsGrxs increased As tolerance in E. coli (Δars) mutant strain (up to 4 mM AsV and up to 0.6 mM AsIII). During AsIII exposure, S. cerevisiae (Δacr3) harboring OsGrx_C7 and OsGrx_C2.1 have lower intracellular AsIII accumulation (up to 30.43% and 24.90%, respectively), compared to vector control. Arsenic accumulation in As-sensitive S. cerevisiae mutant (Δycf1) also reduced significantly on exposure to inorganic As. The expression of OsGrxs in yeast maintained intracellular GSH pool and increased extracellular GSH concentration. Purified OsGrxs displays in vitro GSH-disulfide oxidoreductase, glutathione reductase and arsenate reductase activities. Also, both OsGrxs are involved in AsIII extrusion by altering the Fps1 transcripts in yeast and protect the cell by maintaining cellular GSH pool. Thus, our results strongly suggest that OsGrxs play a crucial role in the maintenance of the intracellular GSH pool and redox status of the cell during both AsV and AsIII stress and might be involved in regulating intracellular AsIII levels by modulation of aquaporin expression and functions.

  14. Accumulation and Fractionation of Rare Earth Elements in Soil-Rice Systems

    2005-01-01

    Accumulation and fractionation of rare earth elements (REEs) were studied through applications of exogenous REEs in soils with pot-cultured rice for 2 years. The results show that the biomass of rice consistently decreases at sproutto exogenous REE exposure is much weaker than that of wheat. The distribution patterns of REEs in rice of the control are similar to that in the soil, both exhibiting light REE (LREE) enrichment and positive Tb in the roots and the aboveground terns of REEs in roots, some effects in stems and leaves, and almost no effects in grains. Accumulation rates of REEs in different organs follow the order of roots > leaves > stems > panicle axes and crusts > grains. The roots take up different REEs at almost the same rates, except for the selective accumulation of Tb. In the aboveground parts, the accumulation rates of middle REEs (MREEs) and heavy REEs (HREEs) are higher than those of LREEs, there are significant selective accumulations of Eu and Tb. Accumulation rates of REEs in the roots, stems and leaves increase with the increasing applications of exogenous REEs, but they change slightly in the panicle axes, crusts and grains, demonstrating that it is easier for the roots, stems and leaves to accumulate exogenous REEs. Selective accumulation and fractionation of exogenous Nd are also observed in rice organs including grains.

  15. 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.

  16. Arsenic accumulation and speciation in rice grown in arsanilic acid-elevated paddy soil.

    Geng, Anjing; Wang, Xu; Wu, Lishu; Wang, Fuhua; Chen, Yan; Yang, Hui; Zhang, Zhan; Zhao, Xiaoli

    2017-03-01

    P-arsanilic acid (AsA) is a emerging but less concerned contaminant used in animal feeding operations, for it can be degraded to more toxic metabolites after being excreted by animals. Rice is the staple food in many parts of the world, and also more efficient in accumulating arsenic (As) compared to other cereals. However, the uptake and transformation of AsA by rice is unclear. This study aimed to evaluate the potential risk of using AsA as a feed additive and using the AsA contaminated animal manure as a fertilizer. Five rice cultivars were grown in soil containing 100mg AsA/kg soil, after harvest, As species and their concentrations in different tissues were determined. Total As concentration of the hybrid rice cultivar was more than conventional rice cultivars for whole rice plant. For rice organs, the highest As concentration was found in roots. AsA could be absorbed by rice, partly degraded and converted to arsenite, monomethylarsonic acid, dimethylarsinic acid, arsenate. The number of As species and their concentrations in each cultivar were related to their genotypes. The soil containing 100mg AsA/kg or more is unsuitable for growing rice. The use of AsA and the disposal of animal manure requires detailed attention.

  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. Identification of variability for agronomically important traits in rice mutant families

    Viviane Kopp da Luz

    2016-03-01

    Full Text Available ABSTRACT The increase of yield potential in new rice (Oryza sativa L. varieties has been a major challenge for genetic improvement. The generation of mutants, followed by their characterization, constitutes a great possibility to isolate and select genes and genotypes that present agronomic traits of interest. This study aimed to evaluate the effect of chemical mutagen ethyl methane sulphonate (EMS on agronomic traits in 340 M3 families of rice derived from BRS Querência cultivar. Seeds from each family and the original genotype BRS Querência were sown in the experimental field, and the characters main panicle length, main panicle weight, main panicle grain weight, flag leaf width and plant height were evaluated. Data were subjected to analysis of variance (p ≤ 0.05, and a comparison of means was carried out by Dunnett's test at 5% significance. The results show that there is genetic variability among the mutant families, suggesting that the mutagen EMS at 1.5% is effective for generating mutants for all assessed traits. Among the characters, plant height was the most affected by the mutagen, which provided an increase in the character. For the main panicle length character, seven families showed means above the control; for main panicle weight and grain weight, four and six mutant families were observed, respectively, with a superior performance in comparison to the control.

  19. 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.

  20. Identiifcation and Genetic Analysis of a Novel Rice Spotted-Leaf Mutant with Broad-Spectrum Resistance to Xanthomonas oryzae pv. oryzae

    SHEN Hai-chao; SHI Yong-feng; FENG Bao-hua; WANG Hui-mei; XU Xia; HUANG Qi-na; LÜ Xiang-guang; WU Jian-li

    2014-01-01

    A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were signiifcantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was signiifcantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1 023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was ifnally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identiifed near the chromosomal region.

  1. Accumulation of SOD1 mutants in postnatal motoneurons does not cause motoneuron pathology or motoneuron disease.

    Lino, Maria Maddalena; Schneider, Corinna; Caroni, Pico

    2002-06-15

    Transgenic mice expressing high levels of familial amyotrophic lateral sclerosis (FALS)-associated mutant superoxide dismutase 1 (SOD1) under the control of a human SOD1 minigene (hMg) accumulate mutant protein ubiquitously and develop motoneuron disease. However, restricted expression of SOD1 mutants in neurons apparently does not cause motor impairments in mice. Here, we investigated the possible pathogenic roles of mutant SOD1 accumulation in motoneurons. First, we used a Thy1 expression cassette to drive high constitutive expression of transgene in postnatal mouse neurons, including upper and lower motoneurons. Second, we expressed human (h) SOD1(G93A) and hSOD1(G85R) as transgenes (i.e., two SOD1 mutants with aggressive pathogenic properties in inducing FALS). Third, in addition to clinical signs of disease, we monitored early signs of disease onset and pathogenesis, including muscle innervation, astrogliosis in the spinal cord, and accumulation of ubiquitinated deposits in motoneurons and astrocytes. We report that high-level expression and accumulation of the mutant proteins in neurons failed to produce any detectable sign of pathology or disease in these transgenic mice. Crossing hMg-SOD1(G93A) mice (Gurney et al., 1994) with Thy1-SOD1(G93A) mice produced double-transgenic mice with spinal cord SOD1(G93A) levels that were approximately twofold higher than in the hMg-SOD1(G93A) single transgenics but did not affect the onset or progression of pathology or motoneuron disease. The accumulation of mutant SOD1 in postnatal motoneurons is thus not sufficient and probably also not critical to induce or accelerate motoneuron disease in FALS mice. The pathogenic process in FALS may involve non-neuronal cells, and selective vulnerability of motoneurons to this process may lead to motoneuron pathology and disease.

  2. 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.

  3. A rice mutant displaying a heterochronically elongated internode carries a 100 kb deletion

    Mika Hayashi-Tsugane; Masahiko Maekawa; Qian Qian; Hirokazu Kobayashi; Shigeru Iida; Kazuo Tsugane

    2011-01-01

    We have isolated a recessive rice mutant,designated as indeterminate growth(ing),which displays creeping and apparent heterochronic phenotypes in the vegetative period with lanky and winding culms.Rough mapping and subsequent molecular characterization revealed that the ing mutant carries a large deletion,which corresponds to a 103 kb region in the Nipponbare genome,containing nine annotated genes on chromosome 3.Of these annotated genes,the SLRI gene encoding a DELLA protein is the only one that is well characterized in its function,and its null mutation,which is caused by a single base deletion in the middle of the intronless SLR1 gene,confers a slender phenotype that bears close resemblance to the ing mutant phenotype.The primary cause of the ing mutant phenotype is the deletion of the SLR1 gene,and the ing mutant appears to be the first characterized mutant having the entire SLRI sequence deleted.Our results also suggest that the deleted region of 103 kb does not contain an indispensable gene,whose dysfunction must result in a lethal phenotype.

  4. Understanding reduced inorganic mercury accumulation in rice following selenium application: Selenium application routes, speciation and doses.

    Tang, Wenli; Dang, Fei; Evans, Douglas; Zhong, Huan; Xiao, Lin

    2017-02-01

    Selenium (Se) has recently been demonstrated to reduce inorganic mercury (IHg) accumulation in rice plants, while its mechanism is far from clear. Here, we aimed at exploring the potential effects of Se application routes (soil or foliar application with Se), speciation (selenite and selenate), and doses on IHg-Se antagonistic interactions in soil-rice systems. Results of our pot experiments indicated that soil application but not foliar application could evidently reduce tissue IHg concentrations (root: 0-48%, straw: 15-58%, and brown rice: 26-74%), although both application routes resulted in comparable Se accumulation in aboveground tissues. Meanwhile, IHg distribution in root generally increased with amended Se doses in soil, suggesting antagonistic interactions between IHg and Se in root. These results provided initial evidence that IHg-Se interactions in the rhizosphere (i.e., soil or rice root), instead of those in the aboveground tissues, could probably be more responsible for the reduced IHg bioaccumulation following Se application. Furthermore, Se dose rather than Se speciation was found to be more important in controlling IHg accumulation in rice. Our findings regarding the importance of IHg-Se interactions in the rhizosphere, together with the systematic investigation of key factors affecting IHg-Se antagonism and IHg bioaccumulation, advance our understanding of Hg dynamics in soil-rice systems.

  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. 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.

  7. Characterization and mapping of a novel light-dependent lesion mimic mutant Imm6 in rice (Oryza sativa L.)

    XIAO Gui-qing[1,2; ZHANG Hal-wen[3; LU Xiang-yang[1,2; HUANG Rong-feng[3

    2015-01-01

    A novel rice lesion mimic mutant (LMM) was isolated from an ethane methyl sulfonate (EMS)-induced 02428 mutant bank. The mutant, tentatively designated as Imm6, develops necrotic lesions in the whole growth period along with changes in several important agronomic traits. We found that the initiation of the lesions was induced by light and cell death occurred in Imm6 accompanied with accumulation of reactive oxygen species (ROS). The lower chlorophyll content, soluble protein content and superoxide dismutase (SOD) activity, the higher malondialdehyde (MDA) content were detected in Imm6 than in the wild type (WT). Moreover, the observation by transmission electronic microscope (TEM) demonstrated that some organelles were damaged and the stroma lamella of chloroplast was irregular and loose in mesophyll cell of Imm6. In addition, Imm6 was more resistant than WT to rice blast fungus Magnaporthe grisea infection, which was consistent with increased expression of four genes involved in the defense-related reaction. Genetic analysis showed that mutant trait of Imm6 is inherited as a monogenic recessive nuclear gene located on the long arm of chromosome 6. Using simple sequence repeat (SSR) markers, the target gene was finally delimited to an interval of 80.8 kb between markers MM2359 and MM2370, containing 7 annotated genes. Taken together, our results provide the information to identify a new gene involved in rice lesion mimic, which will be helpful in clarifying the mechanism of cell death and disease resistance in rice.

  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. Organ fusion and defective shoot development in oni3 mutants of rice

    Akiba, Takafumi; Hibara, Ken-Ichiro; Kimura, Fumiko; Tsuda, Katsutoshi; Shibata, Kiko; Ishibashi, Mayu; Moriya, Chihiro; Nakagawa, Kiyotaka; Kurata, Nori; Itoh, Jun-Ichi; Ito, Yukihiro

    2014-01-01

    Maintenance of organ separation is one of the essential phenomena for normal plant development. We have identified and analyzed ONION3 (ONI3), which is required for avoiding organ fusions in rice. Loss-of-function mutations of ONI3, which were identified as mutants with ectopic expression of KNOX genes in leaves and morphologically resembling KNOX overexpressors, showed abnormal organ fusions in developing shoots. The mutant seedlings showed fusions between neighboring organs and also within an organ; they stopped growing soon after germination and subsequently died. ONI3 was shown to encode an enzyme that is most similar to Arabidopsis HOTHEAD and is involved in biosynthesis of long-chain fatty acids. Expression analyses showed that ONI3 was specifically expressed in the outermost cell layer in the shoot apex throughout life cycle, and the oni3 mutants had an aberrant outermost cell layer. Our results together with previous studies suggest that long-chain fatty acids are required for avoiding organ fusions and promoting normal shoot development in rice. PMID:24192297

  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. MutMap+: genetic mapping and mutant identification without crossing in rice.

    Rym Fekih

    Full Text Available Advances in genome sequencing technologies have enabled researchers and breeders to rapidly associate phenotypic variation to genome sequence differences. We recently took advantage of next-generation sequencing technology to develop MutMap, a method that allows rapid identification of causal nucleotide changes of rice mutants by whole genome resequencing of pooled DNA of mutant F2 progeny derived from crosses made between candidate mutants and the parental line. Here we describe MutMap+, a versatile extension of MutMap, that identifies causal mutations by comparing SNP frequencies of bulked DNA of mutant and wild-type progeny of M3 generation derived from selfing of an M2 heterozygous individual. Notably, MutMap+ does not necessitate artificial crossing between mutants and the wild-type parental line. This method is therefore suitable for identifying mutations that cause early development lethality, sterility, or generally hamper crossing. Furthermore, MutMap+ is potentially useful for gene isolation in crops that are recalcitrant to artificial crosses.

  12. MutMap+: Genetic Mapping and Mutant Identification without Crossing in Rice

    Abe, Akira; Natsume, Satoshi; Yaegashi, Hiroki; Sharma, Shailendra; Sharma, Shiveta; Kanzaki, Hiroyuki; Matsumura, Hideo; Saitoh, Hiromasa; Mitsuoka, Chikako; Utsushi, Hiroe; Uemura, Aiko; Kanzaki, Eiko; Kosugi, Shunichi; Yoshida, Kentaro; Cano, Liliana; Kamoun, Sophien; Terauchi, Ryohei

    2013-01-01

    Advances in genome sequencing technologies have enabled researchers and breeders to rapidly associate phenotypic variation to genome sequence differences. We recently took advantage of next-generation sequencing technology to develop MutMap, a method that allows rapid identification of causal nucleotide changes of rice mutants by whole genome resequencing of pooled DNA of mutant F2 progeny derived from crosses made between candidate mutants and the parental line. Here we describe MutMap+, a versatile extension of MutMap, that identifies causal mutations by comparing SNP frequencies of bulked DNA of mutant and wild-type progeny of M3 generation derived from selfing of an M2 heterozygous individual. Notably, MutMap+ does not necessitate artificial crossing between mutants and the wild-type parental line. This method is therefore suitable for identifying mutations that cause early development lethality, sterility, or generally hamper crossing. Furthermore, MutMap+ is potentially useful for gene isolation in crops that are recalcitrant to artificial crosses. PMID:23874658

  13. Genetic analysis and gene mapping of a narrow leaf mutant in rice (Oryza sativa L.)

    WANG DeKai; LIU HeQin; LI KeLei; LI SuJuan; TAO YueZhi

    2009-01-01

    A narrow leaf mutant was obtained after T-DNA transformation conducted on a rice variety Zhonghua 11. Several abnormal morphological characteristics, including semi-dwarf, delayed flowering time, narrow and inward rolling leaves, and lower seed-setting, were observed. The rate of net photosynthesis (un-der saturate light) of flag leaves in the mutant was significantly lower than that of the wild type. More-over, the leaf transpiration rate and stomatal conductance in the mutant flag leaf were lower than those of the wild type at the grain filling stage. It was found that the mutant phenotype was not caused by the T-DNA insertion. Genetic analysis showed that the mutant was controlled by a single recessive gene,designated as nal3(t). A genetic linkage map was constructed using a large F2 mapping population de-rived from a cross between nal3(t) and an indica variety Longtefu B with 6 polymorphic markers on chromosome 12 identified from 366 SSR markers by the BAS method. Gene nal3(t) was mapped be-tween the markers RM7018 and RM3331. Fine mapping of nal3(t) locus was conducted with 22 newly developed STS markers based on the sequence diversity around the region harboring nal3(t) between Nipponbare and 93-11, and nal3(f) was finally mapped to a 136-kb region between the STS markers NS10 and RH12-8.

  14. Genetic analysis and preliminary gene mapping of a novel seeding yellow leaf mutant in rice

    GE Shaoxing

    2013-02-01

    Full Text Available A novel seeding yellow-leaf mutant, syl11(seedling yellow leaf 11,was found in rice mutant pool from japonica variety,Nipponbare,treated by 60Coγ-radiation.In comparison with the wild-type parent (Nipponbare,the mutant displayed the phenotype of yellow on the 2nd and 3rd leaf and began to turn green from its top before they completely expanded besides the significantly decreased contents of photosynthetic pigments,but all leaves become normal green after the 4-leaf-old stage.The genetic analysis indicated that the mutant trait was controlled by a single recessive nuclear gene.In addition,with the help of SSR,new developed InDel markers and F2 segregating population derived from the cross between the syl11 mutant and Peiai64S,the syl11 was mapped between RM26652(on the long armand ID11974(closing to the centromereon chromosome 11,with a genetic distance of 0.5cM and 0.7cM,respectively.

  15. Isolation and characterisation of a dwarf rice mutant exhibiting defective gibberellins biosynthesis.

    Ji, S H; Gururani, M A; Lee, J W; Ahn, B-O; Chun, S-C

    2014-03-01

    We have isolated a severe dwarf mutant derived from a Ds (Dissociation) insertion mutant rice (Oryza sativa var. japonica c.v. Dongjin). This severe dwarf phenotype, has short and dark green leaves, reduced shoot growth early in the seedling stage, and later severe dwarfism with failure to initiate flowering. When treated with bioactive GA3 , mutants are restored to the normal wild-type phenotype. Reverse transcription PCR analyses of 22 candidate genes related to the gibberellin (GA) biosynthesis pathway revealed that among 22 candidate genes tested, a dwarf mutant transcript was not expressed only in one OsKS2 gene. Genetic analysis revealed that the severe dwarf phenotype was controlled by recessive mutation of a single nuclear gene. The putative OsKS2 gene was a chromosome 4-located ent-kaurene synthase (KS), encoding the enzyme that catalyses an early step of the GA biosynthesis pathway. Sequence analysis revealed that osks2 carried a 1-bp deletion in the ORF region of OsKS2, which led to a loss-of-function mutation. The expression pattern of OsKS2 in wild-type cv Dongjin, showed that it is expressed in all organs, most prominently in the stem and floral organs. Morphological characteristics of the dwarf mutant showed dramatic modifications in internal structure and external morphology. We propose that dwarfism in this mutant is caused by a point mutation in OsKS2, which plays a significant role in growth and development of higher plants. Further investigation on OsKS2 and other OsKS-like proteins is underway and may yield better understanding of the putative role of OsKS in severe dwarf mutants.

  16. The toc132toc120 heterozygote mutant of Arabidopsis thaliana accumulates reduced levels of hexadecatrienoic acid.

    Afitlhile, Meshack; Duffield-Duncan, Kayla; Fry, Morgan; Workman, Samantha; Hum-Musser, Sue; Hildebrand, David

    2015-11-01

    A null and heterozygous mutant for the Arabidopsis thaliana TOC132 and TOC120 genes accumulates increased levels of 16:0 and decreased 16:3, suggesting altered homeostasis in fatty acid synthesis. The FAD5 gene encodes a plastid desaturase that catalyzes the first step in the synthesis of 16:3 in monogalactosyldiacylglycerol (MGDG). In non-acclimated toc132toc120+/- mutant plants, the FAD5 gene was repressed and this correlated with decreased levels of 16:3. In cold-acclimated mutant however, the FAD5 gene was upregulated and there was a small increase in 16:3 levels relative to the non-acclimated mutant plants. The MGD1 gene was expressed at control levels and the mutant accumulated levels of MGDG that were similar to the wild type. In the mutant however, MGDG had decreased 16:3 levels, suggesting that the activity of FAD5 desaturase was compromised. In the mutant, the FAD2 and FAD3 genes were downregulated but levels of 18:3-PC were increased, suggesting posttranscriptional regulation for the ER-localized fatty acid desaturases. The Toc120 or Toc159 receptor is likely to compensate for a defective Toc132 receptor. In the cold-acclimated mutant, the TOC159 gene was repressed ca. 300-fold, whereas the TOC120 gene was repressed 7-fold relative to the non-acclimated wild type. Thus, the TOC159 gene is more sensitive to cold-stress and might not compensate for defect in the TOC132 gene under these conditions. Overall, these data show that a mutation in the TOC132 gene results in decreased 16:3 levels, indicating the need for an intact Toc132/Toc120 receptor, presumably to facilitate the import of the FAD5 preprotein into chloroplasts.

  17. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

    Ouyang Xiaosen

    2011-06-01

    Full Text Available Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease activities may contribute to toxicity whereas others are consistent with protection. These discrepancies may be due to a number of mechanisms including distinct effects of the specific intermediate digestion products of mutant huntingtin generated by different proteases. These observations suggested a critical need to investigate the consequence of upregulation of individual lysosomal enzyme in mutant huntingtin accumulation and toxicity. Results In this study, we used molecular approaches to enhance lysosomal protease activities and examined their effects on mutant huntingtin level and toxicity. We found that enhanced expression of lysosomal cathepsins D and B resulted in their increased enzymatic activities and reduced both full-length and fragmented huntingtin in transfected HEK cells. Furthermore, enhanced expression of cathepsin D or B protected against mutant huntingtin toxicity in primary neurons, and their neuroprotection is dependent on macroautophagy. Conclusions These observations demonstrate a neuroprotective effect of enhancing lysosomal cathepsins in reducing mutant huntingtin level and toxicity in transfected cells. They highlight the potential importance of neuroprotection mediated by cathepsin D or B through macroautophagy.

  18. Cadmium accumulation characteristics and removal potentials of high cadmium accumulating rice line grown in cadmium-contaminated soils.

    Tang, Hao; Li, Tingxuan; Yu, Haiying; Zhang, Xizhou

    2016-08-01

    Phytoextraction is a promising technique to remove cadmium (Cd) from contaminated soils. In this research, the two different Cd accumulation rice lines of Lu527-8 (the high Cd accumulating rice line) and Lu527-4 (the normal rice line) were grown in soils with different Cd treatments (0, 5, 10, and 20 mg kg(-1) soil) to evaluate Cd accumulation characteristics and Cd removal potentials. When the concentration of Cd in soil increased, Lu527-8 showed less symptoms of phytotoxicity when compared to Lu527-4. Furthermore, Lu527-8 demonstrated greater shoot Cd accumulation (321.17-964.95 mg plant(-1)) than Lu527-4 (50.37-201.66 μg plant(-1)) at the jointing and filling stages. The soil available Cd content of Lu527-8 significantly decreased by 26.92-38.97 and 27.77-63.44 % at the jointing and filling stages, respectively. Meanwhile, the total Cd content in soil also reduced by 11.64-46.75 and 21.41-54.11 % at jointing and filling stages, respectively. When the Cd concentration in soil was 20 mg kg(-1), the Cd extraction rate in shoots of Lu527-8 reached 2.12 and 2.85 % which increased 10.60 and 6.48 times compared with that of Lu527-4 at the jointing and filling stages, respectively. In conclusion, this study demonstrates that Lu527-8 shows great abilities of Cd accumulation and Cd removal potential from contaminated soils with different Cd treatments and it is a promising species for phytoextraction of Cd-contaminated soils.

  19. 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.

  20. Brain beta-amyloid accumulation in transgenic mice expressing mutant superoxide dismutase 1.

    Turner, Bradley J; Li, Qiao-Xin; Laughton, Katrina M; Masters, Colin L; Lopes, Elizabeth C; Atkin, Julie D; Cheema, Surindar S

    2004-12-01

    Oxidative stress is implicated in both the deposition and pathogenesis of beta-amyloid (Abeta) protein in Alzheimer's disease (AD). Accordingly, overexpression of the antioxidant enzyme superoxide dismutase 1 (SOD1) in neuronal cells and transgenic AD mice reduces Abeta toxicity and accumulation. In contrast, mutations in SOD1 associated with amyotrophic lateral sclerosis (ALS) confer enhanced pro-oxidative enzyme activities. We therefore examined whether ALS-linked mutant SOD1 overexpression in motor neuronal cells or transgenic ALS mice modulates Abeta toxicity or its accumulation in the brain. Aggregated, but not freshly solubilised, substrate-bound Abeta peptides induced degenerative morphology and cytotoxicity in motor neuron-like NSC-34 cells. Transfection of NSC-34 cells with human wild-type SOD1 attenuated Abeta-induced toxicity, however this neuroprotective effect was also observed for ALS-linked mutant SOD1. Analysis of the cerebral cortex, brainstem, cerebellum and olfactory bulb from transgenic SOD1G93A mice using enzyme-linked immunosorbent assay of acid-guanidine extracts revealed age-dependent elevations in Abeta levels, although not significantly different from wild-type mouse brain. In addition, brain amyloid protein precursor (APP) levels remained unaltered as a consequence of mutant SOD1 expression. We therefore conclude that mutant SOD1 overexpression promotes neither Abeta toxicity nor brain accumulation in these ALS models.

  1. 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.

  2. Characterization of SSIIIa-deficient mutants of rice: the function of SSIIIa and pleiotropic effects by SSIIIa deficiency in the rice endosperm.

    Fujita, Naoko; Yoshida, Mayumi; Kondo, Tomonori; Saito, Kaori; Utsumi, Yoshinori; Tokunaga, Takashi; Nishi, Aiko; Satoh, Hikaru; Park, Jin-Hee; Jane, Jay-Lin; Miyao, Akio; Hirochika, Hirohiko; Nakamura, Yasunori

    2007-08-01

    Starch synthase IIIa (SSIIIa)-deficient rice (Oryza sativa) mutants were generated using retrotransposon insertion and chemical mutagenesis. The lowest migrating SS activity bands on glycogen-containing native polyacrylamide gel, which were identified to be those for SSIIIa, were completely absent in these mutants, indicating that they are SSIIIa null mutants. The amylopectin B(2) to B(4) chains with degree of polymerization (DP) >/= 30 and the M(r) of amylopectin in the mutant were reduced to about 60% and 70% of the wild-type values, respectively, suggesting that SSIIIa plays an important part in the elongation of amylopectin B(2) to B(4) chains. Chains with DP 6 to 9 and DP 16 to 19 decreased while chains with DP 10 to 15 and DP 20 to 25 increased in the mutants amylopectin. These changes in the SSIIIa mutants are almost opposite images of those of SSI-deficient rice mutant and were caused by 1.3- to 1.7-fold increase of the amount of SSI in the mutants endosperm. Furthermore, the amylose content and the extralong chains (DP >/= 500) of amylopectin were increased by 1.3- and 12-fold, respectively. These changes in the composition in the mutants starch were caused by 1.4- to 1.7-fold increase in amounts of granules-bound starch synthase (GBSSI). The starch granules of the mutants were smaller with round shape, and were less crystalline. Thus, deficiency in SSIIIa, the second major SS isozyme in developing rice endosperm affected the structure of amylopectin, amylase content, and physicochemical properties of starch granules in two ways: directly by the SSIIIa deficiency itself and indirectly by the enhancement of both SSI and GBSSI gene transcripts.

  3. 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.

  4. 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.

  5. A proteomic study of rice cultivar TNG67 and its high aroma mutant SA0420.

    Lin, Da-Gin; Chou, Szu-Yi; Wang, Arthur Z; Wang, Yi-Wen; Kuo, Shu-Ming; Lai, Chien-Chen; Chen, Liang-Jwu; Wang, Chang-Sheng

    2014-01-01

    Fragrance is a very important economic trait for rice cultivars. To identify the aroma genes in rice, we performed a proteomics analysis of aroma-related proteins between Tainung 67 (TNG67) and its high aroma mutant SA0420. Seventeen of the differentially identified proteins were close related with the aroma phenotype of SA0420. Among them, 9 were found in leaves and 8 were found in grains. One protein (L3) was identified as the chloroplastic glyceraldehyde-3-phosphate dehydrogenase B (OsGAPDHB) which was less abundant in SA0420 than TNG67. Sequence analysis demonstrated that this protein in SA0420 carries a P425S mutation in the C-terminal extension domain, which might hinder the formation of holoenzyme, thereby changing the profile of aroma compounds. The protein profile of OsGAPDHB showed only a weak correlation to its transcription profile. This result indicated that the reduction of OsGAPDHB in SA0420 is regulated by post-translational processes and can only be analyzed by proteomics approach. Transgenic lines suppressing OsGAPDHB through RNAi harbored more fragrance than TNG67 but less than SA0420. With betaine-aldehyde dehydrogenase as the only fragrance gene identified in rice to date, OsGAPDHB may serve as the second protein known to contribute to the aroma phenotype.

  6. Characterization and Fine Mapping of a Novel Rice Narrow Leaf Mutant nal9

    Wei Li; Wenzhen Liu; Chao Wu; Guocheng Hu; Li Xing; Wenjing Qian; Huamin Si; Zongxiu Sun; Xingchun Wang; Yaping Fu

    2013-01-01

    A narrow leaf mutant was isolated from transgenic rice (Oryza sativa L.) lines carrying a T-DNA insertion. The mutant is characterized by narrow leaves during its whole growth period, and was named nal9 (narrow leaf 9). The mutant also has other phenotypes, such as light green leaves at the seedling stage, reduced plant height, a small panicle and increased tillering. Genetic analysis revealed that the mutation is controlled by a single recessive gene. A hygromycin resistance assay showed that the mutation was not caused by T-DNA insertion, so a map-based cloning strategy was employed to isolate the nal9 gene. The mutant individuals from the F2 generations of a cross between the nal9 mutant and Longtepu were used for mapping. With 24 F2 mutants, the nal9 gene was preliminarily mapped near the marker RM156 on the chromosome 3. New INDEL markers were then designed based on the sequence differences between japonica and indica at the region near RM156. The nal9 gene was finally located in a 69.3 kb region between the markers V239B and V239G within BAC OJ1212_C05 by chromosome walking. Sequence and expression analysis showed that an ATP-dependent Clp protease proteolytic subunit gene (ClpP) was most likely to be the nal9 gene. Furthermore, the nal9 mutation was rescued by transformation of the ClpP cDNA driven by the 35S promoter. Accordingly, the ClpP gene was identified as the NAL9 gene. Our results provide a basis for functional studies of NAL9 in future work.

  7. SUMO-2 and PIAS1 Modulate Insoluble Mutant Huntingtin Protein Accumulation

    Jacqueline Gire O’Rourke

    2013-07-01

    Full Text Available A key feature in Huntington disease (HD is the accumulation of mutant Huntingtin (HTT protein, which may be regulated by posttranslational modifications. Here, we define the primary sites of SUMO modification in the amino-terminal domain of HTT, show modification downstream of this domain, and demonstrate that HTT is modified by the stress-inducible SUMO-2. A systematic study of E3 SUMO ligases demonstrates that PIAS1 is an E3 SUMO ligase for both HTT SUMO-1 and SUMO-2 modification and that reduction of dPIAS in a mutant HTT Drosophila model is protective. SUMO-2 modification regulates accumulation of insoluble HTT in HeLa cells in a manner that mimics proteasome inhibition and can be modulated by overexpression and acute knockdown of PIAS1. Finally, the accumulation of SUMO-2-modified proteins in the insoluble fraction of HD postmortem striata implicates SUMO-2 modification in the age-related pathogenic accumulation of mutant HTT and other cellular proteins that occurs during HD progression.

  8. SUMO-2 and PIAS1 modulate insoluble mutant huntingtin protein accumulation.

    O'Rourke, Jacqueline Gire; Gareau, Jaclyn R; Ochaba, Joseph; Song, Wan; Raskó, Tamás; Reverter, David; Lee, John; Monteys, Alex Mas; Pallos, Judit; Mee, Lisa; Vashishtha, Malini; Apostol, Barbara L; Nicholson, Thomas Peter; Illes, Katalin; Zhu, Ya-Zhen; Dasso, Mary; Bates, Gillian P; Difiglia, Marian; Davidson, Beverly; Wanker, Erich E; Marsh, J Lawrence; Lima, Christopher D; Steffan, Joan S; Thompson, Leslie M

    2013-07-25

    A key feature in Huntington disease (HD) is the accumulation of mutant Huntingtin (HTT) protein, which may be regulated by posttranslational modifications. Here, we define the primary sites of SUMO modification in the amino-terminal domain of HTT, show modification downstream of this domain, and demonstrate that HTT is modified by the stress-inducible SUMO-2. A systematic study of E3 SUMO ligases demonstrates that PIAS1 is an E3 SUMO ligase for both HTT SUMO-1 and SUMO-2 modification and that reduction of dPIAS in a mutant HTT Drosophila model is protective. SUMO-2 modification regulates accumulation of insoluble HTT in HeLa cells in a manner that mimics proteasome inhibition and can be modulated by overexpression and acute knockdown of PIAS1. Finally, the accumulation of SUMO-2-modified proteins in the insoluble fraction of HD postmortem striata implicates SUMO-2 modification in the age-related pathogenic accumulation of mutant HTT and other cellular proteins that occurs during HD progression.

  9. 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.

  10. Accumulation of mercury in rice grain and cabbage grown on representative Chinese soils

    Chun-fa LIU; Ting-qiang LI; Xiao-e YANG; Cheng-xian WU; Muhammad T. RAFIQ; Rukhsanda AZIZ; Dan-di HOU; Zhe-li DING; Zi-wen LIN; Lin-jun LOU; Yuan-yuan FENG

    2013-01-01

    A pot culture experiment was carried out to investigate the accumulation properties of mercury (Hg) in rice grain and cabbage grown in seven soil types (Udic Ferrisols, Mol isol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols) spiked with different concentrations of Hg (CK, 0.25, 0.50, 1.00, 2.00, and 4.00 mg/kg). The results of this study showed that Hg accumulation of plants was significantly affected by soil types. Hg concentration in both rice grain and cabbage increased with soil Hg concentrations, but this increase differed among the seven soils. The stepwise multiple regression analysis showed that pH, Mn(II), particle size distribution, and cation exchange capacity have a close relationship with Hg accumulation in plants, which suggested that physico-chemical characteristics of soils can affect the Hg accumulation in rice grain and cabbage. Critical Hg concentrations in seven soils were identified for rice grain and cabbage based on the maximum safe level for daily intake of Hg, dietary habits of the population, and Hg accumulation in plants grown in different soil types. Soil Hg limits for rice grain in Udic Ferrisols, Mol isol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols were 1.10, 2.00, 2.60, 2.78, 1.53, 0.63, and 2.17 mg/kg, respectively, and critical soil Hg levels for cabbage are 0.27, 1.35, 1.80, 1.70, 0.69, 1.68, and 2.60 mg/kg, respectively.

  11. Accumulation of mercury in rice grain and cabbage grown on representative Chinese soils.

    Liu, Chun-fa; Wu, Cheng-xian; Rafiq, Muhammad T; Aziz, Rukhsanda; Hou, Dan-di; Ding, Zhe-li; Lin, Zi-wen; Lou, Lin-jun; Feng, Yuan-yuan; Li, Ting-qiang; Yang, Xiao-e

    2013-12-01

    A pot culture experiment was carried out to investigate the accumulation properties of mercury (Hg) in rice grain and cabbage grown in seven soil types (Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols) spiked with different concentrations of Hg (CK, 0.25, 0.50, 1.00, 2.00, and 4.00 mg/kg). The results of this study showed that Hg accumulation of plants was significantly affected by soil types. Hg concentration in both rice grain and cabbage increased with soil Hg concentrations, but this increase differed among the seven soils. The stepwise multiple regression analysis showed that pH, Mn(II), particle size distribution, and cation exchange capacity have a close relationship with Hg accumulation in plants, which suggested that physicochemical characteristics of soils can affect the Hg accumulation in rice grain and cabbage. Critical Hg concentrations in seven soils were identified for rice grain and cabbage based on the maximum safe level for daily intake of Hg, dietary habits of the population, and Hg accumulation in plants grown in different soil types. Soil Hg limits for rice grain in Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols were 1.10, 2.00, 2.60, 2.78, 1.53, 0.63, and 2.17 mg/kg, respectively, and critical soil Hg levels for cabbage are 0.27, 1.35, 1.80, 1.70, 0.69, 1.68, and 2.60 mg/kg, respectively.

  12. Stability of soil organic matter accumulated under long-term use as a rice paddy

    Nakahara, Shiko; Zou, Ping; Ando, Ho; Fu, Jianrong; Cao, Zhihong; Nakamura, Toshio; Sugiura, Yuki; Watanabe, Akira

    2016-01-01

    To understand the mechanism responsible for the enhanced accumulation of soil organic matter (SOM) under long-term use as a rice paddy, soil samples from the plow layer from 16 fields that have been used for irrigated rice production from 5 to 2000 years in the Hangzhou Bay, China, were analyzed. The humin in silt/clay particles was isolated as a representative relatively stable SOM pool, and isotopic signatures (δ13C, δ15N, and 14C concentration), 13C nuclear magnetic resonance (NMR) spectra, and biodegradability in an incubation were examined. The amounts of C and N in the bulk soil, silt/clay, and silt/clay-humin increased with increasing period of use as a rice paddy within the east and west zones, respectively. The degree of humification determined for humic acids indicated that the progression of humification did not contribute to the accumulation of C beyond 100 years. The δ15N of silt/clay-humin suggested an increase in organic N derived from chemical fertilizer or recent biological fixation with increasing amount of this fraction. The 14C concentration showed a negative correlation with the amount of silt/clay-humin C. The structural property with regard to 13C NMR spectra and biodegradability of the silt/clay-humin remained constant with the length of use as a rice paddy or 14C concentration. These results suggest that the larger C or N accumulation in the soils with a longer rice paddy history can be attributed to an enhancement in the accumulation of recently generated SOM rather than the stable accumulation of humus over the years.

  13. Research on the ultrafast fluorescence property of thylakoid membranes of the wild-type and mutant rice

    任兆玉; 许晓明; 王水才; 辛越勇; 贺俊芳; 侯洵

    2003-01-01

    A high yielding rice variety mutant (Oryza sativa L., Zhenhui 249) with low chlorophyll b (Chl b) has been discovered in natural fields. It has a quality character controlled by a pair of recessive genes (nuclear gene). The partial loss of Chl b in content affects the efficiency of light harvest in a light harvest complex (LHC), thus producing the difference of the exciting energy transfer and the efficiency of photochemistry conversion between the mutant and wild-type rice in photosynthetic unit. The efficiency of utilizing light energy is higher in the mutant than that in the wildtype rice relatively. For further discussion of the above-mentioned difference and learning about the mechanism of the increase in the photochemical efficiency of the mutant, the pico-second resolution fluorescence spectrum measurement with delay-frame-scanning single photon counting technique is adopted. Thylakoid membranes of the mutant and the wild-type rice are excited by an Ar+ laser with a pulse width of 120ps, repetition rate of 4MHz and wavelength of 514nm. Compared with the time and spectrum property of exciting fluorescence, conclusions of those ultrafast dynamic experiments are: 1) The speeds of the exciting energy transferred in photo-system I are faster than that in photo-system II in both samples. 2) The speeds of the exciting energy transfer of mutant sample are faster than those of the wildtype. This might be one of the major reasons why the efficiency of photosynthesis is higher in mutant than that in the wild-type rice.

  14. 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.

  15. 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)

  16. Growth deficiency of a Xanthomonas oryzae pv. oryzae fur mutant in rice leaves is rescued by ascorbic acid supplementation.

    Subramoni, Sujatha; Sonti, Ramesh V

    2005-07-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. A mutation was isolated in the ferric uptake regulator (fur) gene of X. oryzae pv. oryzae and it was shown to result in the production of siderophores in a constitutive manner. The fur mutant is hypersensitive to the metallo-antibiotic streptonigrin, a phenotype that is indicative of intracellular free-iron overload, and also exhibits a slow growth phenotype on rich medium. The fur mutant is virulence deficient, hypersensitive to hydrogen peroxide, and exhibits reduced catalase activity. Exogenous supplementation with ascorbic acid (an antioxidant) rescues the growth deficiency of the fur mutant in rice leaves. The virulence deficiency of the X. oryzae pv. oryzae fur mutant is proposed to be due, at least in part, to an impaired ability to cope with the oxidative stress conditions that are encountered during infection.

  17. Transferring Translucent Endosperm Mutant Gene Wx-mq and Rice Stripe Disease Resistance Gene Stv-bi by Marker-Assisted Selection in Rice (Oryza sativa)

    YAO Shu; CHEN Tao; ZHANG Ya-dong; ZHU Zhen; ZHAO Ling; ZHAO Qing-yong; ZHOU Li-hui; WANG Cai-lin

    2011-01-01

    A high-yielding japonica rice variety,Wuyunjing 7,bred in Jiangsu Province,China as a female parent was crossed with a Japanese rice variety Kantou 194,which carries a rice stripe disease resistance gene Stv-b1 and a translucent endosperm mutant gene Wx-mq.From F2 generations,a sequence characterized amplified region (SCAR) marker tightly linked with Stv-b1 and a cleaved amplified polymorphic sequence (CAPS) marker for Wx-mq were used for marker-assisted selection.Finally,a new japonica rice line,Ning 9108,with excellent agronomic traits was obtained by multi-generational selection on stripe disease resistance and endosperm appearance.The utilization of the markers from genes related to rice quality and disease resistance was helpful not only for establishing a marker-assisted selection system of high-quality and disease resistance for rice but also for providing important intermediate materials and rapid selection method for good quality,disease resistance and high yield in rice breeding.

  18. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization.

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11-4.28 and 4.78-7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52-3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48-4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26-9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield.

  19. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11–4.28 and 4.78–7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52–3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48–4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26–9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield. PMID:28174589

  20. Characterization and Genetic Analysis of a Novel Rice Spotted-leaf Mutant HM47 with Broad-spectrum Resistance to Xanthomonas oryzae pv.oryzae(F)

    Bao-Hua Feng; Yang Yang; Yong-Feng Shi; Hai-Chao Shen; Hui-Mei Wang; Qi-Na Huang; Xia Xu

    2013-01-01

    A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified.The mutant expressed hypersensitive response (HR)-like symptoms throughout its whole life from the first leaf to the flag leaf,without pathogen invasion.Initiation of the lesions was induced by light under natural summer field conditions.Expression of pathogenesis-related genes including PAL,PO-C1,POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type (WT).Disease reaction to Xanthomonas oryzae pv.oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested.An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions.Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene,tentatively named splHM47,flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4.Ten open reading frames are predicted,and all of them are expressed proteins.Isolation and validation of the putative genes are currently underway.

  1. 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.

  2. Isolation and characterization of a spotted leaf 32 mutant with early leaf senescence and enhanced defense response in rice

    Sun, Liting; Wang, Yihua; Liu, Ling-long; Wang, Chunming; Gan, Ting; Zhang, Zhengyao; Wang, Yunlong; Wang, Di; Niu, Mei; Long, Wuhua; Li, Xiaohui; Zheng, Ming; Jiang, Ling; Wan, Jianmin

    2017-01-01

    Leaf senescence is a complex biological process and defense responses play vital role for rice development, their molecular mechanisms, however, remain elusive in rice. We herein reported a rice mutant spotted leaf 32 (spl32) derived from a rice cultivar 9311 by radiation. The spl32 plants displayed early leaf senescence, identified by disintegration of chloroplasts as cellular evidence, dramatically decreased contents of chlorophyll, up-regulation of superoxide dismutase enzyme activity and malondialdehyde, as physiological characteristic, and both up-regulation of senescence-induced STAY GREEN gene and senescence-associated transcription factors, and down-regulation of photosynthesis-associated genes, as molecular indicators. Positional cloning revealed that SPL32 encodes a ferredoxin-dependent glutamate synthase (Fd-GOGAT). Compared to wild type, enzyme activity of GOGAT was significantly decreased, and free amino acid contents, particularly for glutamate and glutamine, were altered in spl32 leaves. Moreover, the mutant was subjected to uncontrolled oxidative stress due to over-produced reactive oxygen species and damaged scavenging pathways, in accordance with decreased photorespiration rate. Besides, the mutant showed higher resistance to Xanthomonas oryzae pv. Oryzae than its wild type, coupled with up-regulation of four pathogenesis-related marker genes. Taken together, our results highlight Fd-GOGAT is associated with the regulation of leaf senescence and defense responses in rice. PMID:28139777

  3. 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.

  4. Resistance to Bacterial Leaf Blight in a Somaclonal Rice Mutant HX-3 at Cellular Level

    GAO Dong-ying; ZHOU Yi-hong; HUANG Xue-qing; SUN Li-hua; LIU Ai-min

    2004-01-01

    The interaction between rice host and its pathogen Xanthomonas oryzae pv. oryzae (Xoo) at cellular level was studied by using a resistant somaclonal mutant HX-3 and its susceptable donor Minghui 63. After inoculation with Xoo strain Zhe 173 (Chinese pathotype Ⅳ), the activity of superoxide dismutase (SOD) and peroxidase (POD) in the callus of Minghui 63 was increased dramatically, and the active oxygen(O2 - .) was produced at a higher rate; Meanwhile, the callus grew slowly with the reduction of protein content. Compared to the activity of SOD and POD, the production rate of O2-. and the fresh weight in HX-3 callus varied little after the inoculation. It could be proposed that there were great differences between the resistance of HX-3 and Mighui 63 at cellular level. There was no difference detected concerning resistance to bacterial leaf blight in HX-3 between the plant and the callus.

  5. Characterization and mapping of a new male sterility mutant of anther advanced dehiscence (t) in rice

    Yi Zhang; Yunfeng Li; Jian Zhang; Fucheng Shen; Yuanxin Huang; Zhiwei Wu

    2008-01-01

    Anther dehiscence is very important for pollen maturation and release.The mutants of anther dehiscence in rice (Oryza sativa L.) arefew,and related research remains poor.A male sterility mutant of anther dehiscence in advance,add(t),has been found in Minghui 63 and its sterility is not sensitive to thermo-photo.To learn the character of sterilization and the function of the add(t) gene,the morphological and cytological studies on the anther and pollen,the ability of the pistil being fertilized,inheritance of the mutant,and mapping of add(t)gene have been conducted.The anther size is normal but the color is white in the mutant against the natural yellow in the wild-type.The pollen is malformed,unstained,and small in the KI-I2 solution.The anther dehiscence is in advance at the bicellular pollen stage.A crossing test indicated that the grain setting ratio of the add(t) is significantly lower than that of the CMS line 2085A.The ability of the pistil being fertilized is most probably decreased by the add(t) gene.The male sterility is controlled by a single recessive gene of add(t).This gene is mapped between the markers of R02004 (InDel) and RM300 (SSR) on chromosome 2,and the genetic distance from the add(t) gene to these markers is 0.78 cM and 4.66 cM,respectively.

  6. Function and characterization of starch synthase I using mutants in rice.

    Fujita, Naoko; Yoshida, Mayumi; Asakura, Noriko; Ohdan, Takashi; Miyao, Akio; Hirochika, Hirohiko; Nakamura, Yasunori

    2006-03-01

    Four starch synthase I (SSI)-deficient rice (Oryza sativa) mutant lines were generated using retrotransposon Tos17 insertion. The mutants exhibited different levels of SSI activities and produced significantly lower amounts of SSI protein ranging from 0% to 20% of the wild type. The mutant endosperm amylopectin showed a decrease in chains with degree of polymerization (DP) 8 to 12 and an increase in chains with DP 6 to 7 and DP 16 to 19. The degree of change in amylopectin chain-length distribution was positively correlated with the extent of decrease in SSI activity in the mutants. The structural changes in the amylopectin increased the gelatinization temperature of endosperm starch. Chain-length analysis of amylopectin in the SSI band excised from native-polyacrylamide gel electrophoresis/SS activity staining gel showed that SSI preferentially synthesized DP 7 to 11 chains by elongating DP 4 to 7 short chains of glycogen or amylopectin. These results show that SSI distinctly generates DP 8 to 12 chains from short DP 6 to 7 chains emerging from the branch point in the A or B(1) chain of amylopectin. SSI seemingly functions from the very early through the late stage of endosperm development. Yet, the complete absence of SSI, despite being a major SS isozyme in the developing endosperm, had no effect on the size and shape of seeds and starch granules and the crystallinity of endosperm starch, suggesting that other SS enzymes are probably capable of partly compensating SSI function. In summary, this study strongly suggested that amylopectin chains are synthesized by the coordinated actions of SSI, SSIIa, and SSIIIa isoforms.

  7. Facilitation of Rice Stripe Virus Accumulation in the Insect Vector by Himetobi P Virus VP1

    Shuo Li

    2015-03-01

    Full Text Available The small brown planthopper (SBPH is the main vector for rice stripe virus (RSV, which causes serious rice stripe disease in East Asia. To characterize the virus-vector interactions, the SBPH cDNA library was screened with RSV ribonucleoprotein (RNP as bait using a GAL4-based yeast two-hybrid system. The interaction between RSV-RNP and the Himetobi P virus (HiPV, an insect picorna-like virus VP1 protein was identified. The relationships between HiPV and RSV in SBPH were further investigated, and the results showed that the titer of RSV was commonly higher in single insect that exhibited more VP1 expression. After the VP1 gene was repressed by RNA silencing, the accumulation of RSV decreased significantly in the insect, whereas the virus acquisition ability of SBPH was unaffected, which suggests that HiPV VP1 potentially facilitates the accumulation of RSV in SBPH.

  8. 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...

  9. 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.

  10. Anatomical and Chemical Characteristics of a Rolling Leaf Mutant of Rice and Its Ecophysiological Properties

    BAI Lei; DUAN Zhuang-qin; WANG Jun-min; AN Li-zhe; ZHAO Zhi-guang; CHEN Kun-ming

    2008-01-01

    The anatomical and chemical characteristics of a rolling leaf mutant (r/m) of rice (Oryza sativa L.) and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type (WT),the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in r/m, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared (FTIR) microspectroscopy spectra of foliar cell walls differed greatly between r/m and WT. The r/m exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in r/m by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in r/m than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant.

  11. 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.

  12. 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.

  13. Effects of Nitrogen and Shading on Root Morphologies, Nutrient Accumulation, and Photosynthetic Parameters in Different Rice Genotypes.

    Pan, Shenggang; Liu, Haidong; Mo, Zhaowen; Patterson, Bob; Duan, Meiyang; Tian, Hua; Hu, Shuijing; Tang, Xiangru

    2016-08-25

    Nitrogen availability and illumination intensity are two key factors which affect rice growth. However, their influences on total nitrogen accumulation, photosynthetic rate, root morphologies, and yields are not fully understood. We conducted two field experiments to (1) evaluate the effects of shading under different N treatments on photosynthetic parameters, root morphologies, total nutrient accumulation, and grain yields of rice; and (2) elucidate the relationship between total nutrient accumulation and root morphologies under different shading conditions and nitrogen treatments. Three nitrogen rates, three shading treatments, and three different rice cultivars were used in two field experiments. Double shading during the grain-filling stage decreased total nutrient accumulation, altered root morphological characteristics, and decreased yields in rice. There were also significant interaction effects between nitrogen and shading on photosynthetic rate, transpiration rate, and total root length, root superficial area, and root volume. Significant interactions were found among cultivars and shading for photosynthetic rate and transpiration rate. Correlation analysis revealed that total nitrogen accumulation (TNA) and potassium accumulation (TKA) were significantly positively correlated with total root length, root superficial area, and root volume. N application could alleviate the detrimental effects of shading on total nutrient accumulation and grain yield in rice.

  14. Studies on the Photosynthetic Characteristics and Assimilate's Accumulation and Transformation in Heavy Panicle Type of Rice

    MA Jun; ZHU Qing-sen; MA Wen-bo; TIAN Yan-hua; Yang Jian-chang; ZHOU Kai-da

    2003-01-01

    Using 18 indiea rice varieties with different panicle weight, the photosynthetic characteristics and assimilate's accumulation and transformation in heavy panicle type of rice (HPT) were studied. The resuits showed that the net photosynthetic rate of the flag leaf in HPT after heading was obviously higher than that in medium panicle type(MPT) and light panicle type(LPT). The reason for the high net photosynthetic rate in HPT was the increase of Rubisco activities and chlorophyll content, and keeping high assimilate ability to CO2 under high and low light intensity, high temperature and low CO2 content, and light midday depression and wide adaptability to environmental conditions. The high net photosynthetic rate of HPT might be also the results of its excellent stomatal characteristics and higher total quantity of stomatal opening degrees(stomatal density X stomatal opening degrees). There was a large amount of dry matter production after heading and obvious high assimilate's transformation to panicle in HPT.

  15. Phosphorus Deficiency Alters Nutrient Accumulation Patterns and Grain Nutritional Quality in Rice

    Terry J. Rose

    2016-10-01

    Full Text Available The accumulation of biomass and mineral nutrients during the post-anthesis period was investigated in field-grown rice plants cultivated in phosphorus (P-sufficient vs. P-deficient soil. Phosphorus deficiency reduced biomass accumulation by around 30%, and reduced the accumulation of all nutrients in aboveground plant biomass except sulfur (S and copper (Cu. Ultimately, grain zinc (Zn, Cu, and calcium (Ca concentrations were significantly higher in P-deficient plants, while grain magnesium (Mg concentrations were significantly lower. While P deficiency caused a 40% reduction in the concentration of the anti-nutrient phytate in the grain, this was offset by a 40% reduction in grain starch lysophospholipids, which have positive benefits for human health and grain quality.

  16. 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.

  17. [Effects of different nitrogen, phosphorous, and potassium fertilization modes on carbon- and nitrogen accumulation and allocation in rice plant].

    Feng, Lei; Tong, Cheng-li; Shi, Hui; Wu, Jin-shui; Chen, An-lei; Zhou, Ping

    2011-10-01

    Based on a 20-year field site-specific fertilization experiment in Taoyuan Experimental Station of Agriculture Ecosystems under Chinese Ecosystem Research Network (CERN), this paper studied the effects of different fertilization modes of N, P, and K on the accumulation and allocation of C and N in rice plant. The fertilization mode N-only showed the highest C and N contents (433 g kg(-1) and 18.9 g kg(-1), respectively) in rice grain, whereas the modes balanced fertilization of chemical N, P and K (NPK) and its combination with organic mature recycling (NPKC) showed the highest storage of C and N in rice plant. In treatments NPK and NPKC, the C storage in rice grain and in stem and leaf was 1960 kg hm(-2) and 2015 kg hm(-2), and 2002 kg hm(-2) and 2048 kg hm(-2), and the N storage in rice grain was 80.5 kg hm(-2) and 80.6 kg hm(-2), respectively. Treatment NPK had the highest N storage (59.3 kg hm(-2)) in stem and leaf. Balanced fertilization of chemical N, P, and K combined with organic manure recycling increased the accumulation of C and N in rice plant significantly. Comparing with applying N only, balanced fertilization of chemical N, P, and K was more favorable to the accumulation and allocation of C and N in rice plant during its growth period.

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

    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 ...

  19. 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.

  20. 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.

  1. 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

  2. Identification of rice ethylene-response mutants and characterization of MHZ7/OsEIN2 in distinct ethylene response and yield trait regulation.

    Ma, Biao; He, Si-Jie; Duan, Kai-Xuan; Yin, Cui-Cui; Chen, Hui; Yang, Chao; Xiong, Qing; Song, Qing-Xin; Lu, Xiang; Chen, Hao-Wei; Zhang, Wan-Ke; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2013-11-01

    Ethylene plays essential roles in adaptive growth of rice plants in water-saturating environment; however, ethylene signaling pathway in rice is largely unclear. In this study, we report identification and characterization of ethylene-response mutants based on the specific ethylene-response phenotypes of etiolated rice seedlings, including ethylene-inhibited root growth and ethylene-promoted coleoptile elongation, which is different from the ethylene triple-response phenotype in Arabidopsis. We establish an efficient system for screening and a set of rice mutants have been identified. Genetic analysis reveals that these mutants form eight complementation groups. All the mutants show insensitivity or reduced sensitivity to ethylene in root growth but exhibit differential responses in coleoptile growth. One mutant group mhz7 has insensitivity to ethylene in both root and coleoptile growth. We identified the corresponding gene by a map-based cloning method. MHZ7 encodes a membrane protein homologous to EIN2, a central component of ethylene signaling in Arabidopsis. Upon ethylene treatment, etiolated MHZ7-overexpressing seedlings exhibit enhanced coleoptile elongation, increased mesocotyl growth and extremely twisted short roots, featuring enhanced ethylene-response phenotypes in rice. Grain length was promoted in MHZ7-transgenic plants and 1000-grain weight was reduced in mhz7 mutants. Leaf senescent process was also affected by MHZ7 expression. Manipulation of ethylene signaling may improve adaptive growth and yield-related traits in rice.

  3. Do radial oxygen loss and external aeration affect iron plaque formation and arsenic accumulation and speciation in rice?

    Wu, Chuan; Ye, Zhihong; Li, Hui; Wu, Shengchun; Deng, Dan; Zhu, Yongguan; Wong, Minghung

    2012-05-01

    Hydroponic experiments were conducted to investigate the effect of radial oxygen loss (ROL) and external aeration on iron (Fe) plaque formation, and arsenic (As) accumulation and speciation in rice (Oryza sativa L.). The data showed that there were significant correlations between ROL and Fe concentrations in Fe plaque produced on different genotypes of rice. There were also significant differences in the amounts of Fe plaque formed between different genotypes in different positions of roots and under different aeration conditions (aerated, normal, and stagnant treatments). In aerated treatments, rice tended to have a higher Fe plaque formation than in a stagnant solution, with the greatest formation at the root tip decreasing with increasing distances away, in accordance with a trend of spatial ROL. Genotypes with higher rates of ROL induced higher degrees of Fe plaque formation. Plaques sequestered As on rice roots, with arsenate almost double that with arsenite, leading to decreased As accumulation in both roots and shoots. The major As species detected in roots and shoots was arsenite, ranging from 34 to 78% of the total As in the different treatments and genotypes. These results contribute to our understanding of genotypic differences in As uptake by rice and the mechanisms causing rice genotypes with higher ROL to show lower overall As accumulation.

  4. Altered cell wall properties are responsible for ammonium-reduced aluminium accumulation in rice roots.

    Wang, Wei; Zhao, Xue Qiang; Chen, Rong Fu; Dong, Xiao Ying; Lan, Ping; Ma, Jian Feng; Shen, Ren Fang

    2015-07-01

    The phytotoxicity of aluminium (Al) ions can be alleviated by ammonium (NH4(+)) in rice and this effect has been attributed to the decreased Al accumulation in the roots. Here, the effects of different nitrogen forms on cell wall properties were compared in two rice cultivars differing in Al tolerance. An in vitro Al-binding assay revealed that neither NH4(+) nor NO3(-) altered the Al-binding capacity of cell walls, which were extracted from plants not previously exposed to N sources. However, cell walls extracted from NH4(+)-supplied roots displayed lower Al-binding capacity than those from NO3(-)-supplied roots when grown in non-buffered solutions. Fourier-transform infrared microspectroscopy analysis revealed that, compared with NO3(-)-supplied roots, NH4(+)-supplied roots possessed fewer Al-binding groups (-OH and COO-) and lower contents of pectin and hemicellulose. However, when grown in pH-buffered solutions, these differences in the cell wall properties were not observed. Further analysis showed that the Al-binding capacity and properties of cell walls were also altered by pHs alone. Taken together, our results indicate that the NH4(+)-reduced Al accumulation was attributed to the altered cell wall properties triggered by pH decrease due to NH4(+) uptake rather than direct competition for the cell wall binding sites between Al(3+) and NH4(+).

  5. Fluorescent Trimethoprim Conjugate Probes To Assess Drug Accumulation in Wild Type and Mutant Escherichia coli

    2016-01-01

    Reduced susceptibility to antimicrobials in Gram-negative bacteria may result from multiple resistance mechanisms, including increased efflux pump activity or reduced porin protein expression. Up-regulation of the efflux pump system is closely associated with multidrug resistance (MDR). To help investigate the role of efflux pumps on compound accumulation, a fluorescence-based assay was developed using fluorescent derivatives of trimethoprim (TMP), a broad-spectrum synthetic antibiotic that inhibits an intracellular target, dihydrofolate reductase (DHFR). Novel fluorescent TMP probes inhibited eDHFR activity with comparable potency to TMP, but did not kill or inhibit growth of wild type Escherichia coli. However, bactericidal activity was observed against an efflux pump deficient E. coli mutant strain (ΔtolC). A simple and quick fluorescence assay was developed to measure cellular accumulation of the TMP probe using either fluorescence spectroscopy or flow cytometry, with validation by LC-MS/MS. This fluorescence assay may provide a simple method to assess efflux pump activity with standard laboratory equipment. PMID:27737551

  6. Transcript profiling of crown rootless1 mutant stem base reveals new elements associated with crown root development in rice

    Van Anh Le Thi

    2011-08-01

    Full Text Available Abstract Background In rice, the major part of the post-embryonic root system is made of stem-derived roots named crown roots (CR. Among the few characterized rice mutants affected in root development, crown rootless1 mutant is unable to initiate crown root primordia. CROWN ROOTLESS1 (CRL1 is induced by auxin and encodes an AS2/LOB-domain transcription factor that acts upstream of the gene regulatory network controlling CR development. Results To identify genes involved in CR development, we compared global gene expression profile in stem bases of crl1 mutant and wild-type (WT plants. Our analysis revealed that 250 and 236 genes are down- and up-regulated respectively in the crl1 mutant. Auxin induces CRL1 expression and consequently it is expected that auxin also alters the expression of genes that are early regulated by CRL1. To identify genes under the early control of CRL1, we monitored the expression kinetics of a selected subset of genes, mainly chosen among those exhibiting differential expression, in crl1 and WT following exogenous auxin treatment. This analysis revealed that most of these genes, mainly related to hormone, water and nutrient, development and homeostasis, were likely not regulated directly by CRL1. We hypothesized that the differential expression for these genes observed in the crl1 mutant is likely a consequence of the absence of CR formation. Otherwise, three CRL1-dependent auxin-responsive genes: FSM (FLATENNED SHOOT MERISTEM/FAS1 (FASCIATA1, GTE4 (GENERAL TRANSCRIPTION FACTOR GROUP E4 and MAP (MICROTUBULE-ASSOCIATED PROTEIN were identified. FSM/FAS1 and GTE4 are known in rice and Arabidopsis to be involved in the maintenance of root meristem through chromatin remodelling and cell cycle regulation respectively. Conclusion Our data showed that the differential regulation of most genes in crl1 versus WT may be an indirect consequence of CRL1 inactivation resulting from the absence of CR in the crl1 mutant. Nevertheless

  7. Low cadmium (LCD), a novel gene related to cadmium tolerance and accumulation in rice.

    Shimo, Hugo; Ishimaru, Yasuhiro; An, Gynheung; Yamakawa, Takashi; Nakanishi, Hiromi; Nishizawa, Naoko K

    2011-11-01

    The contamination of food crops by cadmium (Cd) is a major concern in food production because it can reduce crop yields and threaten human health. In this study, knockout rice plants (Oryza sativa) tagged with the gene trap vector pGA2707 were screened for Cd tolerance, and the tolerant line lcd was obtained. The lcd mutant showed tolerance to Cd on agar plates and in hydroponic culture during early plant development. Metal concentration measurements in hydroponically grown plants revealed significantly less Cd in the shoots of lcd plants compared with wild-type (WT) shoots. When cultured in the field in soil artificially contaminated with low levels of Cd, lcd showed no significant difference in the Cd content of its leaf blades; however, the Cd concentration in the grains was 55% lower in 2009 and 43% lower in 2010. There were no significant differences in plant dry weight or seed yield between lcd and wild-type plants. LCD, a novel gene, is not homologous to any other known gene. LCD localized to the cytoplasm and nucleus, and was expressed mainly in the vascular tissues in the roots and phloem companion cells in the leaves. These data indicate that lcd may be useful for understanding Cd transport mechanisms and is a promising candidate rice line for use in combating the threat of Cd to human health.

  8. 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...

  9. Cadmium accumulation retard activity of functional components of photo assimilation and growth of rice cultivars amended with vermicompost.

    Sebastian, Abin; Prasad, M N V

    2013-01-01

    Cadmium (Cd) uptake mediated alterations in functional components of photo assimilation during conversion of cow dung and poultry cast to vermicompost were studied in two Indian rice cultivars; MO 16 and MTU 7029. It was found that higher amount of Cd accumulate in plants grown in soil amended with vermicompost which in turn damaged functional components in photo assimilation. Enhancement of root growth was recognized as reason for Cd accumulation. Metabolic alterations noticed among plants were not taken place during application of raw materials used for vermicomposting such as cow dung and poultry cast amendment. Rice varieties accumulated Cd differentially where MTU 7029 accumulated more Cd compare to MO 16. It was also noticed that existence of negative correlation between zinc status of the plant and Cd accumulation.

  10. Arsenate and arsenite exposure modulate antioxidants and amino acids in contrasting arsenic accumulating rice (Oryza sativa L.) genotypes.

    Dave, Richa; Tripathi, Rudra Deo; Dwivedi, Sanjay; Tripathi, Preeti; Dixit, Garima; Sharma, Yogesh Kumar; Trivedi, Prabodh Kumar; Corpas, Francisco J; Barroso, Juan B; Chakrabarty, Debasis

    2013-11-15

    Carcinogenic arsenic (As) concentrations are found in rice due to irrigation with contaminated groundwater in South-East Asia. The present study evaluates comparative antioxidant property and specific amino acid accumulation in contrasting rice genotypes corresponding to differential As accumulation during arsenate (As(V)) and arsenite (As(III)) exposures. The study was conducted on two contrasting As accumulating rice genotypes selected from 303 genotype accessions, in hydroponic conditions. Maximum As accumulation was up to 1181 μg g(-1) dw in the roots of high As accumulating genotype (HARG), and 89 μg g(-1) dw in low As accumulating genotype (LARG) under As(III) exposures. The inorganic As was correlated more significantly upon exposures to As(III) than As(V). In the presence of As(V) various antioxidant enzymes guiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were highly stimulated in HARG. The stress responsive amino acids proline, cysteine, glycine, glutamic acid and methionine showed higher accumulation in HARG than LARG. A clear correlation was found between stress responsive amino acids, As accumulation and antioxidative response. The comparisons between the contrasting genotypes helped to determine the significance of antioxidants and specific amino acid response to As stress.

  11. 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

  12. [Effect of fertilization on the absorption, partition and accumulation of carbon and nitrogen of rice under the equal N conditions].

    Feng, Lei; Tong, Cheng-Li; Shi, Hui; Wu, Jin-Shui; Li, Yong; Huang, Tie-Ping; Xia, Hai-Ao

    2011-02-01

    In this study, the assimilation, partition and accumulation of carbon (C) and nitrogen (N), as well as the relationship between C and N accumulation of rice, were studied from typical paddy ecosystems under long-term fertilizer applications with equal N inputs in subtropical China. The results showed that chemical fertilizer plus low organic manure (LOM) could promote effectively the distribution of C in the rice plant. The N content in the stem-leaf and grain of rice under organic-inorganic fertilization was 8.9-10.2 g x kg(-1) and 11.9-14.8 g x kg(-1) respectively. It was much higher than under other treatments, with about 13% - 53% and 9% - 19% higher than under the chemical fertilization (NPK), separately and 12% - 77% and 23% - 32% higher than under the control treatment (CK), respectively. The C and N storages of rice were mainly accumulated in the aboveground part. Organic-inorganic fertilization treatment possessed higher storages of C (3467.8-4 323.9 kg x hm(-2)) and N (120.3-135.2 kg x hm(-2)) in the rice grain,which was about 13% - 23% of C and 26% - 45% of N higher than under NPK treatment. It indicated that rice grain was the main sink of C and N. The organic-inorganic fertilization was in favor of C accumulation and N absorption in the rice plant and it still possesses an obvious potential in C and N sequestration and absorption in subtropical paddy field.

  13. 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.

  14. 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.

  15. Growing rice aerobically markedly decreases mercury accumulation by reducing both Hg bioavailability and the production of MeHg.

    Wang, Xun; Ye, Zhihong; Li, Bing; Huang, Linan; Meng, Mei; Shi, Jianbo; Jiang, Guibin

    2014-01-01

    Rice consumption represents a major route of mercury (Hg) and methylmercury (MeHg) exposure for those living in certain areas of inland China. In this study we investigated the effects of water management on bioavailable Hg, MeHg, and sulfate-reducing bacteria (SRB, abundance and community composition) in rhizosphere soil, and total Hg (THg) and MeHg in rice plants grown under glasshouse and paddy field conditions. Aerobic conditions greatly decreased the amount of THg and MeHg taken up by rice plants and affected their distribution in different plant tissues. There were positive correlations between bioavailable Hg and THg in brown rice and roots and between numbers of SRB and MeHg in brown rice, roots, and rhizosphere soil. Furthermore, the community composition of SRB was dramatically influenced by the water management regimes. Our results demonstrate that the greatly reduced bioavailability of Hg and production of MeHg are due to decreased SRB numbers and proportion of Hg methylators in the rhizosphere under aerobic conditions. These are the main reasons for the reduced Hg and MeHg accumulation in aerobically grown rice. Water management is indicated as an effective measure that can be used to reduce Hg and MeHg uptake by rice plants from Hg-contaminated paddy fields.

  16. Do arbuscular mycorrhizal fungi affect arsenic accumulation and speciation in rice with different radial oxygen loss?

    Li, H; Man, Y B; Ye, Z H; Wu, C; Wu, S C; Wong, M H

    2013-11-15

    The effects of arbuscular mycorrhizal fungi (AMF) on the temporal variation of arsenic (As) speciation and accumulation in two paddy rice cultivars (TD 71 and Xiushui 11) with different degrees of radial oxygen loss (ROL) at three growth periods (day 7, day 35, day 63 after flooding the soil) were investigated in soil, spiked with and without 30 mg As kg(-1). The results showed that TD 71 with high ROL colonized by Glomus intraradices led to higher root colonization rates than Xiushui 11 at three growth periods, both in soil with or without 30 mg As kg(-1) (p<0.05). Mycorrhizal inoculation led to elevated (p<0.05) root ratios of arsenite (As(III)) conc./arsenate (As(V)) conc. (concentration) in TD 71 with high ROL at three growth periods in As contaminated flooding soils. Furthermore, the ratios of As(III) conc./As(V) conc. in roots of TD71 were significantly more than Xiushui 11 when colonized by AMF at three growth periods in 30 mg As kg(-1) soil (p<0.05). Therefore, rice with high ROL can favor AM fungal infection and enhance root ratio of As(III) conc./As(V) conc. in the presence of AMF.

  17. 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).

  18. 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.

  19. 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.

  20. [Accumulation of the bvg- Bordetella pertussis a virulent mutants in the process of experimental whooping cough in mice].

    Medkova, A Iu; Siniashina, L N; Rumiantseva, Iu P; Voronina, O L; Kunda, M S; Karataev, G I

    2013-01-01

    The duration of the persistence and dynamics of accumulation of insertion bvg- Bordetella pertussis mutants were studied in lungs of laboratory mice after intranasal and intravenous challenge by virulent bacteria of the causative agent of whooping cough. The capability of the virulent B. pertussis bacteria to long-term persistence in the body of mice was tested. Using the real-time PCR approximately hundred genome equivalents of the B. pertussis DNA were detected in lungs of mice in two months after infection regardless of the way of challenge. Using the bacterial test bacteria were identified during only four weeks after challenge. Bvg- B. pertussis avirulent mutants were accumulated for the infection time. The percentage of the avirulent bacteria in the B. pertussis population reached 50% in 7-9 weeks after challenge. The obtained results show that the laboratory mice can be used for study of the B. pertussis insertion mutant formation dynamics in vivo and confirm the hypothesis about insertional bvg- B. pertussis virulent mutants accumulation during development of pertussis infection in human.

  1. 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.

  2. Altered Disease Development in the eui Mutants and Eui Overexpressors Indicates that Gibberellins Negatively Regulate Rice Basal Disease Resistance

    Dong-Lei Yang; Qun Li; Yi-Wen Deng; Yong-Gen Lou; Mu-Yang Wang; Guo-Xing Zhou; Ying-Ying Zhang; Zu-Hua He

    2008-01-01

    Gibberellins (GAs) form a group of important plant tetracyclic diterpenoid hormones that are involved in many aspects of plant growth and development. Emerging evidence implicates that GAs also play roles in stress responses. However, the role of GAs in biotic stress is largely unknown. Here, we report that knockout or overexpression of the Elongated uppermost internode (Eui) gene encoding a GA deactivating enzyme compromises or increases, respectively, disease resistance to bacterial blight (Xanthomonas oryzae pv. oyrzae) and rice blast (Magnaporthe oryzae). Exogenous application of GA and the inhibitor of GA synthesis (uniconazol) could increase disease susceptibility and resistance, respectively, to bacterial blight. Similarly, uniconazol restored disease resistance of the eui mutant and GA3 decreased disease resistance of the Eui overexpressors to bacterial blight. Therefore, the change of resistance attributes to GA levels. In consistency with this, the GA metabolism genes OsGA2Oox2 and OsGA2oxl were down-regulated during pathogen challenge. We also found that PR1a induction was enhanced but the SA level was decreased in the Eui overexpressor, while the JA level was reduced in the eui mutant. Together, our current study indicates that GAs play a negative role in rice basal disease resistance, with EUI as a positive modulator through regulating the level of bioactive GAs.

  3. Altered disease development in the eui mutants and Eui overexpressors indicates that gibberellins negatively regulate rice basal disease resistance.

    Yang, Dong-Lei; Li, Qun; Deng, Yi-Wen; Lou, Yong-Gen; Wang, Mu-Yang; Zhou, Guo-Xing; Zhang, Ying-Ying; He, Zu-Hua

    2008-05-01

    Gibberellins (GAs) form a group of important plant tetracyclic diterpenoid hormones that are involved in many aspects of plant growth and development. Emerging evidence implicates that GAs also play roles in stress responses. However, the role of GAs in biotic stress is largely unknown. Here, we report that knockout or overexpression of the Elongated uppermost internode (Eui) gene encoding a GA deactivating enzyme compromises or increases, respectively, disease resistance to bacterial blight (Xanthomonas oryzae pv. oyrzae) and rice blast (Magnaporthe oryzae). Exogenous application of GA(3) and the inhibitor of GA synthesis (uniconazol) could increase disease susceptibility and resistance, respectively, to bacterial blight. Similarly, uniconazol restored disease resistance of the eui mutant and GA(3) decreased disease resistance of the Eui overexpressors to bacterial blight. Therefore, the change of resistance attributes to GA levels. In consistency with this, the GA metabolism genes OsGA20ox2 and OsGA2ox1 were down-regulated during pathogen challenge. We also found that PR1a induction was enhanced but the SA level was decreased in the Eui overexpressor, while the JA level was reduced in the eui mutant. Together, our current study indicates that GAs play a negative role in rice basal disease resistance, with EUI as a positive modulator through regulating the level of bioactive GAs.

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

    HEXiu-ying; XuShi-ping; LIAoYao-ping; MAOXing-xue; WENGKe-nan; CHENZhao-ming; CHENYue-han; XIAOWan-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 wcrc 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.

  5. Heterologous expression of Ceratophyllum demersum phytochelatin synthase, CdPCS1, in rice leads to lower arsenic accumulation in grain.

    Shri, Manju; Dave, Richa; Diwedi, Sanjay; Shukla, Devesh; Kesari, Ravi; Tripathi, Rudra Deo; Trivedi, Prabodh Kumar; Chakrabarty, Debasis

    2014-07-22

    Recent studies have identified rice (Oryza sativa) as a major dietary source of inorganic arsenic (As) and poses a significant human health risk. The predominant model for plant detoxification of heavy metals is complexation of heavy metals with phytochelatins (PCs), synthesized non-translationally by PC synthase (PCS) and compartmentalized in vacuoles. In this study, in order to restrict As in the rice roots as a detoxification mechanism, a transgenic approach has been followed through expression of phytochelatin synthase, CdPCS1, from Ceratophyllum demersum, an aquatic As-accumulator plant. CdPCS1 expressing rice transgenic lines showed marked increase in PCS activity and enhanced synthesis of PCs in comparison to non-transgenic plant. Transgenic lines showed enhanced accumulation of As in root and shoot. This enhanced metal accumulation potential of transgenic lines was positively correlated to the content of PCs, which also increased several-fold higher in transgenic lines. However, all the transgenic lines accumulated significantly lower As in grain and husk in comparison to non-transgenic plant. The higher level of PCs in transgenic plants relative to non-transgenic presumably allowed sequestering and detoxification of higher amounts of As in roots and shoots, thereby restricting its accumulation in grain.

  6. Heavy metal accumulation in rice plants. Effects on mineral nutrition and possible interaction of plant hormones

    Rodrigo, M.; Martinez-Cortina, C.; Sanz, A. (Univ. of Valencia, Burjassot (Spain)); Escrig, I.; Lopez-Benet, F.J. (Univ. of Jaume I, Castello (Spain))

    1993-05-01

    As a consequence of anthropogenic activities there is a constant increase in water and soil pollution by heavy metals, which may have negative effect on plants. We have studied the effects of Cd and Ni treatments on mineral nutrition of rice plants. six days after germination. Cd (0.1 mM) or Ni (0.5 mM) was added to the nutrient solution where the plants were grown. After 10 days mineral element contents were analyzed by atomic absorption spectrophotometry after sample digestion with nitric acid (70[degrees]C 24 h) in erlenmeyer flasks. Cd-treated plants accumulated high quantities of this metal (2.28 mg/g DW, 30 fold the value found in controls), and most of it remained in the root (66% of total). A great increase in Ni contents was also observed in Ni-treated plants (3.06 mg/g DW, 28 fold higher than in controls). However, contrary to Cd, Ni accumulated preferentially in shoots (81% of total). Addition of ABA or GA[sub 3] (5 mg/l) to the nutrient solution together with the heavy metal, did not affect Cd uptake by the plants but caused a significant reduction in Ni accumulation in the shoots (60%). In both, Cd- and Ni-treated plants, the uptake of divalent cations (Ca[sup 2][sup +], Mg[sup 2][sup +]) decreased more than 50% with respect to controls. This effect was not modified by hormonal applications, though a trend to reverse the decrease in Ca[sup 2][sup +] caused by Ni was observed.

  7. Root aeration improves growth and nitrogen accumulation in rice seedlings under low nitrogen.

    Zhu, Jingwen; Liang, Jing; Xu, Zhihui; Fan, Xiaorong; Zhou, Quansuo; Shen, Qirong; Xu, Guohua

    2015-11-16

    In wetland soils, changes in oxygen (O2) level in the rhizosphere are believed to influence the behaviour of nutrients and their usage by plants. However, the effect of aeration on nitrogen (N) acquisition under different N supply conditions remains largely unknown. In this study, the rice cultivars Yangdao 6 (YD6, with higher root aerenchyma abundance) and Nongken 57 (NK57, with lower root aerenchyma abundance) were used to evaluate the effects of aeration on rice growth and N accumulation. Our results showed that the number of adventitious roots and the root surface area increased significantly, and ethylene production and aerenchyma formation decreased in both cultivars after external aeration (EA). Five N treatments, including no N (-N), 0.125 mM NH4NO3 (LN), 1.25 mM Ca(NO3)2 (NO3-N), 1.25 mM (NH4)2SO4 (NH4-N) and 1.25 mM NH4NO3 (N/N), were applied to YD6 and NK57 for 2 days under internal aeration or EA conditions. External aeration increased the root biomass in both cultivars and the shoot biomass in NK57 by 18-50 %. The total N concentrations in roots of YD6 grown under -N and LN and of NK57 grown under NO3-N were increased by EA. Expression of OsPAD4, one of four putative genes regulating aerenchyma formation, showed a similar pattern alongside changes in the ethylene level in the EA-treated rice irrespective of the N treatments. Furthermore, expression of the high-affinity nitrate transporter gene OsNRT2.1 was increased by EA under -N, LN and NO3-N conditions. Our data provide evidence of an interaction between O2 and the supply of N in ethylene production, aerenchyma formation and N nutrition through modification of the expression of OsPAD4 and OsNRT2.1.

  8. Influences of Cadmium on Grain Mineral Nutrient Contents of Two Rice Genotypes Differing in Grain Cadmium Accumulation

    CHENG Wang-da; YAO Hai-gen; ZHANG Hong-mei; TAO Xian-guo

    2009-01-01

    A pot experiment was conducted to study the effects of Cd on grain Cd, K, P, Mg, Zn, Cu, Pb, Fe and Mn accumulation in two rice genotypes (Xiushui 63 and Xiushui 217) differing in grain Cd accumulation under four Cd levels, i.e. 0, 0.5, 2.5 and 12.5 mg/kg. Rice genotype greatly affected the grain K content, but not significantly for P, Mg, Zn, Cu, Pb, Fe and Mn contents. There were remarkable effects of additional Cd on the contents of P, Mg and Zn in grains, while not significant for K, Cu, Pb, Fe and Mn contents. No significant differences were found in the interaction of genotype by additional Cd on these nine element contents. The low grain Cd accumulation genotype Xiushui 217 had significantly higher grain K, Mg, Cu and Mn contents than the high grain Cd accumulation genotype Xiushui 63, but the case was opposite for Zn, Pb and Fe contents. It also showed that Cd addition levels significantly influenced the K, P, Mg, Zn, Cu, Pb, Fe and Mn contents in rice grains. Grain K, P, Mg, Zn, Fe and Mn contents reduced with the increasing rate of Cd addition.

  9. Synthetic phytochelatins complement a phytochelatin-deficient Arabidopsis mutant and enhance the accumulation of heavy metal(loid)s.

    Shukla, Devesh; Tiwari, Manish; Tripathi, Rudra D; Nath, Pravendra; Trivedi, Prabodh Kumar

    2013-05-10

    Phytochelatins (PCs) are naturally occurring thiol-rich peptides containing gamma (γ) peptide bonds and are well known for their metal-binding and detoxification capabilities. Whether synthetic phytochelatins (ECs) can be used as an alternative approach for enhancing the metal-binding capacity of plants has been investigated in this study. The metal-binding potential of ECs has been demonstrated in bacteria; however, no report has investigated the expression of ECs in plants. We have expressed three synthetic genes encoding ECs of different lengths in wild type (WT) Arabidopsis (Col-0 background) and a phytochelatin-deficient Arabidopsis mutant (cad1-3). After exposure to different heavy metals, the transgenic plants were examined for phenotypic changes, and metal accumulation was evaluated. The expression of EC genes rescued the sensitive phenotype of the cad1-3 mutant under heavy metal(loid) stress. Transgenic Arabidopsis plants expressing EC genes accumulated a significantly enhanced level of heavy metal(loid)s in comparison with the WT plant. The mutant complementation and enhanced heavy metal(loid) accumulation in the transgenic Arabidopsis plants suggest that ECs work in a manner similar to that of PCs in plants and that ECs could be used as an alternative for phytoremediation of heavy metal(loid) exposure.

  10. Reduction of mutant huntingtin accumulation and toxicity by lysosomal cathepsins D and B in neurons

    Ouyang Xiaosen; Liang Qiuli; Schneider Lonnie; Zhang Jianhua

    2011-01-01

    Abstract Background Huntington's disease is caused by aggregation of mutant huntingtin (mHtt) protein containing more than a 36 polyQ repeat. Upregulation of macroautophagy was suggested as a neuroprotective strategy to degrade mutant huntingtin. However, macroautophagy initiation has been shown to be highly efficient in neurons whereas lysosomal activities are rate limiting. The role of the lysosomal and other proteases in Huntington is not clear. Some studies suggest that certain protease a...

  11. 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 0.14 μmol mmol(-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.

  12. Cell Wall Targeted in planta Iron Accumulation Enhances Biomass Conversion and Seed Iron Concentration in Arabidopsis and Rice

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S.; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S. Charlotte; Carpita, Nicholas C.; Makowski, Lee; Himmel, Michael E.; Tucker, Melvin P.; McCann, Maureen C.; Murphy, Angus S.; Peer, Wendy A.

    2016-10-01

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  13. 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.

  14. [Dynamic changes of rice (Oryza sativa L.) tiller angle under effects of photoperiod and effective accumulated temperature].

    Ouyang, You-Nan; Li, Chun-Sheng; Zhang, Shan-Qing; Wang, Hui-Min; Zhu, Lian-Feng; Yu, Sheng-Miao; Jin, Qian-Yu; Zhang, Guo-Ping

    2009-05-01

    Using rice variety DI508 as test material, a field experiment of different seeding dates and a test with plant growth chamber were conducted to study the dynamic changes of rice tiller angle under effects of different photoperiod and effective accumulated temperature. Under field condition, the tiller angle of DI508 plants changed gradually into erect after 10-15 days of photoperiod becoming shorter (since the Summer Solstice on 21st June), irrespective of seeding dates (4th April, 5th May, and 4th June). Under controlled photoperiod, the tiller angle changed in the same way as in the field. Shorter lighting treatment (10 hours) advanced the tiller angle change, while longer lighting treatment (14 hours) delayed the change. Effective accumulated temperature had no effects on the tiller angle change of DI508.

  15. Recovery and Biological Properties of Nitrate Non-utilizing Mutants of Rice Blast, Magnaporthe grisea

    ZHANG Chuan-qing; ZHOU Ming-guo

    2004-01-01

    Eleven nitrate non-utilizing (nit) mutants were recovered from six isolates of Magnaporthe grisea cultured on MM media amended with 60 g/L potassium chlorate, with a frequency of 1.42 %. Some biological properties, such as growth rate, growth biomass, cultural characters, conidial production, sexual reproduction ability, and pathogenicity were compared between nit mutants and their parent isolates. Results showed that all the nit mutants were resistant to chlorate. Some important biological properties such as the growth rate on YPSA, conidial production ability on TPSA, pathogenicity, had no significant differences between nit mutants and their parent isolates. Mating type didn't change, but perithecia production ability of fertile isolates changed significantly as compared with that of their parent isolates. Therefore, the nit can be used as a genetic marker to study the genetics such as pathogenicity, fungicide resistance in Magnaporthe grisea.

  16. 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

    2012-09-01

    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 [CO(2)]. 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 lines was conducted for the rice SLAC1 orthologue gene Os04g0674700, and four mutant lines containing mutations within the open reading frame were obtained. A second screen using an infrared thermography camera revealed that one of the mutants, named slac1, had a constitutive low leaf temperature phenotype. Measurement of leaf gas exchange showed that slac1 plants grown in the greenhouse had significantly higher stomatal conductance (g (s)), rates of photosynthesis (A), and ratios of internal [CO(2)] to ambient [CO(2)] (C (i)/C (a)) compared with wild-type plants, whereas there was no significant difference in the response of photosynthesis to internal [CO(2)] (A/C (i) curves). These observations demonstrate that in well-watered conditions, stomatal conductance is a major determinant of photosynthetic rate in rice.

  17. 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.

  18. Free mycolic acid accumulation in the cell wall of the mce1 operon mutant strain of Mycobacterium tuberculosis.

    Cantrell, Sally A; Leavell, Michael D; Marjanovic, Olivera; Iavarone, Anthony T; Leary, Julie A; Riley, Lee W

    2013-10-01

    The lipid-rich cell wall of Mycobacterium tuberculosis, the agent of tuberculosis, serves as an effective barrier against many chemotherapeutic agents and toxic host cell effector molecules, and it may contribute to the mechanism of persistence. Mycobacterium tuberculosis strains mutated in a 13-gene operon called mce1, which encodes a putative ABC lipid transporter, induce aberrant granulomatous response in mouse lungs. Because of the postulated role of the mce1 operon in lipid importation, we compared the cell wall lipid composition of wild type and mce1 operon mutant M. tuberculosis H37Rv strains. High resolution mass spectrometric analyses of the mce1 mutant lipid extracts showed unbound mycolic acids to accumulate in the cell wall. Quantitative analysis revealed a 10.7 fold greater amount of free mycolates in the mutant compared to that of the wild type strain. The free mycolates were comprised of alpha, methoxy and keto mycolates in the ratio 1:0.9:0.6, respectively. Since the mce1 operon is regulated in vivo, the free mycolates that accumulate during infection may serve as a barrier for M. tuberculosis against toxic products and contribute to the pathogen's persistence.

  19. 水稻叶色突变体基因定位研究进展%Research Progress on Gene Mapping for Rice Leaf Coloration Mutant

    冯章丽

    2014-01-01

    Rice leaf color mutant is a kind of mutant which is easier to observe and obtain .To fine map the gene controlling the leaf color mutant is benefit to elucidate the regulation mechanism of leaf color gene and genetic improvement of leaf photosynthesis and improve yield of rice .Accordingly ,recent research progress of rice leaf color mutations were reviewed including the types and sources of the leaf coloration mutant ,the genetic mecha-nism of gene mapping and cloning ,molecular mechanism of leaf color mutant and its application in rice was in-troduced ,it was the bases for researching and utilizing the rice leaf color mutation .%水稻叶色突变体是一类较易观察和获得的突变体,研究水稻叶色突变体基因进行定位有助于深入阐明叶色基因的调控机理,对水稻叶片光合遗传改良和产量提高具有重要的指导意义。因此,对于近年来有关水稻叶色突变体的分类来源、遗传机理以及基因定位等研究进展进行综述,并介绍了叶色突变体的分子机理及其在水稻中的应用,旨在为水稻叶色突变体的研究和利用奠定基础。

  20. The tomato res mutant which accumulates JA in roots in non-stressed conditions restores cell structure alterations under salinity.

    Garcia-Abellan, José O; Fernandez-Garcia, Nieves; Lopez-Berenguer, Carmen; Egea, Isabel; Flores, Francisco B; Angosto, Trinidad; Capel, Juan; Lozano, Rafael; Pineda, Benito; Moreno, Vicente; Olmos, Enrique; Bolarin, Maria C

    2015-11-01

    Jasmonic acid (JA) regulates a wide spectrum of plant biological processes, from plant development to stress defense responses. The role of JA in plant response to salt stress is scarcely known, and even less known is the specific response in root, the main plant organ responsible for ionic uptake and transport to the shoot. Here we report the characterization of the first tomato (Solanum lycopersicum) mutant, named res (restored cell structure by salinity), that accumulates JA in roots prior to exposure to stress. The res tomato mutant presented remarkable growth inhibition and displayed important morphological alterations and cellular disorganization in roots and leaves under control conditions, while these alterations disappeared when the res mutant plants were grown under salt stress. Reciprocal grafting between res and wild type (WT) (tomato cv. Moneymaker) indicated that the main organ responsible for the development of alterations was the root. The JA-signaling pathway is activated in res roots prior to stress, with transcripts levels being even higher in control condition than in salinity. Future studies on this mutant will provide significant advances in the knowledge of JA role in root in salt-stress tolerance response, as well as in the energy trade-off between plant growth and response to stress.

  1. Accumulation of mercury and cadmium in rice from paddy soil near a mercury mine.

    Li, W C; Ouyang, Y; Ye, Z H

    2014-11-01

    Paddy soil and rice (Oryza sativa L.) in the Wanshan mining area in Guizhou Province, China, have been contaminated by toxic trace metals such as cadmium (Cd) and mercury (Hg). The present study examined correlations between the types and physicochemical parameters of the soil and the contents of trace metals and the different forms of Hg in rice. The health risks of consuming contaminated rice from the Wanshan mining area were also assessed. Sequential extraction procedures were used to investigate the chemical behavior of Hg in the soil. The results showed that Hg and Cd were the most abundant trace metals in the Wanshan mining area. The toxic methylmercury (MeHg) content was substantial in brown rice, and the total amounts of total Hg (THg), diethylenetriaminepentaacetic acid-Hg, and water-soluble Hg varied in the rhizosphere and non-rhizosphere soils. An antagonistic interaction between Mn in brown rice, straw, and husk and MeHg in brown rice was also shown. An analysis of calculated dietary intake, target hazard quotients, and hazard indexes showed a potential risk of transferring Hg, MeHg, and Cd to humans when rice from the Wanshan mining area is consumed. Therefore, it must be concluded that consuming contaminated rice near the Wanshan mining area is a potential threat to human health.

  2. Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations (Oryza sativa L.)

    唐家斌; 曾万勇; 王文明; 马炳田; 刘勇; 李浩杰; 夏红爱; 李平; 朱立煌

    2001-01-01

    A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent, G069 was further backcrossed with the recurrent parent, 02428, for two turns to develop a BC2F2 population. Genetic analysis in the BC2F2 population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants in BC2F2, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the 02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C424 and S13984 with a genetic distance of 2.4 cM and 0.6 cM, respectively. The gene is designated ft1.

  3. New Rice Mutants(NR676 and NR827)Low in Nitrate Reduction

    2000-01-01

    Mutants deficient in nitrate reductase(NR) were classfied into two groups,nia types are deficient in apoprotein and cnx types are lack of Mo- Co. This paper reports the characteristics of low NR mutants,which are not deficient in NR activity but 40%~60% of the NR activity of the wild type,Nipponbare. Mutants NR676 and NR827 were selected as seedings showing poor growth with nitrate as sole mitrogen source from M2 population. They exhibited chlorate resistance. Genetic analysis in the F1 and F2 indicated that chlorate resistance in the mutants was transmitted by a single recessive nuclear gene and that NR676 and NR827 were induced by a mutation at a single locus. In the F2 population,all of the seedings showing yellow green leaves were resistant to chlorate and low in NR activity. Photosynthetic rate and mRNA expression of NR676 and NR827 were lower than wild type. These results suggested that low NR activity and chlorate resistance of NR676 and NR827 were caused by a defect in photosynthetic process.

  4. 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.

  5. Oxalate Accumulation as Regulated by Nitrogen Forms and Its Relationship to Photosynthesis in Rice (Oryza sativa L.)

    Xiu-Mei JI; Xin-Xiang PENG

    2005-01-01

    Four-leaf rice seedlings (Oryza sativa L.), which had been cultivated in Kimura B complete nutrient solution, were treated with two nitrogen forms by replacing the nitrogen element in the complete solution with sole nitrate or ammonium (2.86 mmol/L). Nitrate-N nutrition tended to increase oxalate content in all parts of the plant, including the leaves, stems, roots, and root exudates, whereas ammonium had the opposite effect. Consequently, marked differences in oxalate content were observed between the two treatments throughout the time tested (0--12 d), with maximal differences of approximately 12-fold at 6 d after treatment. Photosynthetic/respiratory parameters were examined over time simultaneously with changes in oxalate content. Net photosynthetic rate, chlorophyll fluorescence parameters (i.e. maximal photochemical efficiency (Fv/Fm) and photochemical quantum yields of photosystem (PS)Ⅱ (φ PSⅡ)), and respiratory rate were not significantly different between plants treated with the two nitrogen forms, although ammonium-fed plants had apparently higher leaf chlorophyll content than nitrate-fed plants. Leaf glucose content was altered little, but the content of fructose, sucrose, and total soluble sugar was significantly higher in the leaves of ammonium-fed plants than nitrate-fed plants, The results indicate that nitrate/ammonium may serve as efficient regulators of oxalate accumulation owing to regulation of metabolism in rice leaves rather than oxalate downward transfer and root excretion, and that photosynthetic metabolism is not directly correlated with the regulation of oxalate accumulation in rice plants.

  6. Microbial activity promoted with organic carbon accumulation in macroaggregates of paddy soils under long-term rice cultivation

    Liu, Yalong; Wang, Ping; Ding, Yuanjun; Lu, Haifei; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Filley, Timothy; Zhang, Xuhui; Zheng, Jinwei; Pan, Genxing

    2016-12-01

    While soil organic carbon (SOC) accumulation and stabilization has been increasingly the focus of ecosystem properties, how it could be linked to soil biological activity enhancement has been poorly assessed. In this study, topsoil samples were collected from a series of rice soils shifted from salt marshes for 0, 50, 100, 300 and 700 years from a coastal area of eastern China. Soil aggregates were fractioned into different sizes of coarse sand (200-2000 µm), fine sand (20-200 µm), silt (2-20 µm) and clay (communities, soil respiration and enzyme activity. The results showed that the mass proportion both of coarse-sand (2000-200 µm) and clay (management. The finding here provides a mechanistic understanding of soil organic carbon turnover and microbial community succession at fine scale of soil aggregates that have evolved along with anthropogenic activity of rice cultivation in the field.

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

    Phanchaisri, Boonrak [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Samsang, Nuananong [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, Liang Deng; Singkarat, Somsorn [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, Somboon, E-mail: soanu.1@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2012-06-01

    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.

  8. High Silicon Accumulation in the Shoot is Required for Down-Regulating the Expression of Si Transporter Genes in Rice.

    Mitani-Ueno, Namiki; Yamaji, Naoki; Ma, Jian Feng

    2016-12-01

    Rice requires high silicon (Si) for its high and sustainable yield. The efficient uptake of Si in rice is mediated by two transporters OsLsi1 and OsLsi2, which function as influx and efflux transporters, respectively. Our previous studies showed that the mRNA expression levels of these transporter genes were down-regulated by Si. Herein we investigated the mechanism underlying regulation of OsLsi1 and OsLsi2 expression. There was a negative correlation between the expression level of OsLsi1 and OsLsi2 and shoot Si accumulation when the rice seedlings were exposed to different Si supply conditions. A split root experiment showed that the expression of both OsLsi1 and OsLsi2 was also down-regulated in half the roots without direct Si exposure when the other half of the roots were exposed to Si. Analysis with transgenic rice carrying different lengths of OsLsi1 promoter regions fused with green fluorescent protein (GFP) as a reporter gene revealed that the region responsible for the Si response of OsLsi1 expression is present between -327 to -292 in the promoter. However, this region was not associated with the tissue and cellular localization of OsLsi1. In conclusion, the Si-induced down-regulation of Si transporter genes is controlled by shoot Si, not root Si, and the region between -327 and -292 in the OsLsi1 promoter is involved in this regulation of OsLsi1 expression in rice.

  9. Whole genome HBV deletion profiles and the accumulation of preS deletion mutant during antiviral treatment

    Zhang Dake

    2012-12-01

    Full Text Available Abstract Background Hepatitis B virus (HBV, because of its error-prone viral polymerase, has a high mutation rate leading to widespread substitutions, deletions, and insertions in the HBV genome. Deletions may significantly change viral biological features complicating the progression of liver diseases. However, the clinical conditions correlating to the accumulation of deleted mutants remain unclear. In this study, we explored HBV deletion patterns and their association with disease status and antiviral treatment by performing whole genome sequencing on samples from 51 hepatitis B patients and by monitoring changes in deletion variants during treatment. Clone sequencing was used to analyze preS regions in another cohort of 52 patients. Results Among the core, preS, and basic core promoter (BCP deletion hotspots, we identified preS to have the highest frequency and the most complex deletion pattern using whole genome sequencing. Further clone sequencing analysis on preS identified 70 deletions which were classified into 4 types, the most common being preS2. Also, in contrast to the core and BCP regions, most preS deletions were in-frame. Most deletions interrupted viral surface epitopes, and are possibly involved in evading immuno-surveillance. Among various clinical factors examined, logistic regression showed that antiviral medication affected the accumulation of deletion mutants (OR = 6.81, 95% CI = 1.296 ~ 35.817, P = 0.023. In chronic carriers of the virus, and individuals with chronic hepatitis, the deletion rate was significantly higher in the antiviral treatment group (Fisher exact test, P = 0.007. Particularly, preS2 deletions were associated with the usage of nucleos(tide analog therapy (Fisher exact test, P = 0.023. Dynamic increases in preS1 or preS2 deletions were also observed in quasispecies from samples taken from patients before and after three months of ADV therapy. In vitro experiments demonstrated that

  10. Genetic background modifies nuclear mutant huntingtin accumulation and HD CAG repeat instability in Huntington's disease knock-in mice.

    Lloret, Alejandro; Dragileva, Ella; Teed, Allison; Espinola, Janice; Fossale, Elisa; Gillis, Tammy; Lopez, Edith; Myers, Richard H; MacDonald, Marcy E; Wheeler, Vanessa C

    2006-06-15

    Genetically precise models of Huntington's disease (HD), Hdh CAG knock-in mice, are powerful systems in which phenotypes associated with expanded HD CAG repeats are studied. To dissect the genetic pathways that underlie such phenotypes, we have generated Hdh(Q111) knock-in mouse lines that are congenic for C57BL/6, FVB/N and 129Sv inbred genetic backgrounds and investigated four Hdh(Q111) phenotypes in these three genetic backgrounds: the intergenerational instability of the HD CAG repeat and the striatal-specific somatic HD CAG repeat expansion, nuclear mutant huntingtin accumulation and intranuclear inclusion formation. Our results reveal increased intergenerational and somatic instability of the HD CAG repeat in C57BL/6 and FVB/N backgrounds compared with the 129Sv background. The accumulation of nuclear mutant huntingtin and the formation of intranuclear inclusions were fastest in the C57BL/6 background, slowest in the 129Sv background and intermediate in the FVB/N background. Inbred strain-specific differences were independent of constitutive HD CAG repeat size and did not correlate with Hdh mRNA levels. These data provide evidence for genetic modifiers of both intergenerational HD CAG repeat instability and striatal-specific phenotypes. Different relative contributions of C57BL/6 and 129Sv genetic backgrounds to the onset of nuclear mutant huntingtin and somatic HD CAG repeat expansion predict that the initiation of each of these two phenotypes is modified by different genes. Our findings set the stage for defining disease-related genetic pathways that will ultimately provide insight into disease mechanism.

  11. Changes in Starch Accumulation and Activity of Enzymes Associated with Starch Synthesis of Rice at Different N Supplying Dates

    MA Jun; MING Dong-feng; MA Wen-bo; XU Feng-ying

    2004-01-01

    The changes in grain-filling, starch accumulation and activity of enzymes associated with starch synthesis in two different hybrid rice varieties were analyzed at different N supplying dates (earlier-date-emphasized, mean-date-emphasized and later-date-emphasized). The results showed that the N application of later-date-emphasized could promote grain-filling rate, increase grain weight and amylopectin content. The peak of activity in three enzymes of ADPglusoce pyriphosphorylase (ADPG), starch synthesis enzyme (SSS) and starch branching enzyme (SBE) in grains of two different rice varieties was not changed obviously, but the mean and maximum activity of these three enzymes changed, and the changes of SSS and ADPG were bigger than that of SBE as N supplying date changed. The N application of earlier-date-emphasized increased SSS activity and the N application of later-date-emphasized increased ADPG and SBE activities. The mean SSS activity during whole grain-filling period, and ADPG and SBE activities at middle and late period of grain-filling were significantly or very significantly correlated with grain-filling rate and accumulating rate of amylose and amylopectin. Both of ADPG and SBE played an equal important role in the changes of amylose and amylopectin content. The N application of later-date-emphasized increased amylose and amylopectin accumulating rate.

  12. Reduced ABA Accumulation in the Root System is Caused by ABA Exudation in Upland Rice (Oryza sativa L. var. Gaoshan1) and this Enhanced Drought Adaptation.

    Shi, Lu; Guo, Miaomiao; Ye, Nenghui; Liu, Yinggao; Liu, Rui; Xia, Yiji; Cui, Suxia; Zhang, Jianhua

    2015-05-01

    Lowland rice (Nipponbare) and upland rice (Gaoshan 1) that are comparable under normal and moderate drought conditions showed dramatic differences in severe drought conditions, both naturally occurring long-term drought and simulated rapid water deficits. We focused on their root response and found that enhanced tolerance of upland rice to severe drought conditions was mainly due to the lower level of ABA in its roots than in those of the lowland rice. We first excluded the effect of ABA biosynthesis and catabolism on root-accumulated ABA levels in both types of rice by monitoring the expression of four OsNCED genes and two OsABA8ox genes. Next, we excluded the impact of the aerial parts on roots by suppressing leaf-biosynthesized ABA with fluridone and NDGA (nordihydroguaiaretic acid), and measuring the ABA level in detached roots. Instead, we proved that upland rice had the ability to export considerably more root-sourced ABA than lowland rice under severe drought, which improved ABA-dependent drought adaptation. The investigation of apoplastic pH in root cells and root anatomy showed that ABA leakage in the root system of upland rice was related to high apoplastic pH and the absence of Casparian bands in the sclerenchyma layer. Finally, taking some genes as examples, we predicted that different ABA levels in rice roots stimulated distinct ABA perception and signaling cascades, which influenced its response to water stress.

  13. Identification of a phosphinothricin-resistant mutant of rice glutamine synthetase using DNA shuffling.

    Tian, Yong-Sheng; Xu, Jing; Zhao, Wei; Xing, Xiao-Juan; Fu, Xiao-Yan; Peng, Ri-He; Yao, Quan-Hong

    2015-10-23

    To date, only bar/pat gene derived from Streptomyces has been used to generate the commercial PPT-resistant crops currently available in the market. The limited source of bar/pat gene is probably what has caused the decrease in PPT-tolerance, which has become the main concern of those involved in field management programs. Although glutamine synthetase (GS) is the target enzyme of PPT, little study has been reported about engineering PPT-resistant plants with GS gene. Then, the plant-optimized GS gene from Oryza sativa (OsGS1S) was chemically synthesized in the present study by PTDS to identify a GS gene for developing PPT-tolerant plants. However, OsGS1S cannot be directly used for developing PPT-tolerant plants because of its poor PPT-resistance. Thus, we performed DNA shuffling on OsGS1S, and one highly PPT-resistant mutant with mutations in four amino acids (A63E, V193A, T293A and R295K) was isolated after three rounds of DNA shuffling and screening. Among the four amino acids substitutions, only R295K was identified as essential in altering PPT resistance. The R295K mutation has also never been previously reported as an important residue for PPT resistance. Furthermore, the mutant gene has been transformed into Saccharomyces cerevisiae and Arabidopsis to confirm its potential in developing PPT-resistant crops.

  14. Brome mosaic virus Infection of Rice Results in Decreased Accumulation of RNA1.

    Kitayama, Masahiko; Hoover, Haley; Middleton, Stefani; Kao, C Cheng

    2015-05-01

    Brome mosaic virus (BMV) (the Russian strain) infects monocot plants and has been studied extensively in barley and wheat. Here, we report BMV can systemically infect rice (Oryza sativa var. japonica), including cultivars in which the genomes have been determined. The BMV capsid protein can be found throughout the inoculated plants. However, infection in rice exhibits delayed symptom expression or no symptoms when compared with wheat (Triticum aestivum). The sequences of BMV RNAs isolated from rice did not reveal any nucleotide changes in RNA1 or RNA2, while RNA3 had only one synonymous nucleotide change from the inoculum sequence. Preparations of purified BMV virions contained RNA1 at a significantly reduced level relative to the other two RNAs. Analysis of BMV RNA replication in rice revealed that minus-strand RNA1 was replicated at a reduced rate when compared with RNA2. Thus, rice appears to either inhibit RNA1 replication or lacks a sufficient amount of a factor needed to support efficient RNA1 replication.

  15. Analysis of genes specifically expressed under salt stress in salt-tolerant mutant of rice by using DDRT-PCR technique

    张弛; 陈受宜

    1996-01-01

    Differential display reverse transcription-PCR (DDRT-PCR) technique was used to identify those genes that are expressed differentially between wild type rice variety 77-170 (Oryza Sativa vas Japonica) and its salt-tolerant mutant (M-20) under salt stress. Totally 13 salt-inducible cDNA fragments of 200-600 bp were identified and doned, and were designated as SIGR1 - SIGR13 (salt-induced gene in rice). Northern blot analysis showed that expression of SIGR6 and SIGR8 was salt-inducible in both wild type and mutant, and expression of SIGR12 in M-20 was much higher than that in 77-170 under salt stress. It was also shown that expression of SIGR3, SIGR4, SIGR7, SIGRIO and SIGR13 was salt-inducible, and the genes were highly homologous with Rab1d which was an ABA-inducible gene of rice. The great potential application of DDRT-PCR technique in plant molecular biology research may promote the investigation of expression of salt-induced protein in rice.

  16. Morphological and starch structural characteristics of the Japonica rice mutant variety Seolgaeng for dry-milled flour

    Producing fine, good quality rice flour is more difficult than wheat flour because the rice grain is harder. In this study, we analyzed the relationship between the morphology and starch of kernels from genetically different rice varieties that can be used to make dry-milled flour. The non-glutinous...

  17. Tlr4-mutant mice are resistant to acute alcohol-induced sterol-regulatory element binding protein activation and hepatic lipid accumulation

    Zhang, Zhi-Hui; Liu, Xiao-Qian; Zhang, Cheng; He, Wei; Wang, Hua; Chen, Yuan-Hua; Liu, Xiao-Jing; Chen, Xi; Xu, De-Xiang

    2016-01-01

    Previous studies demonstrated that acute alcohol intoxication caused hepatic lipid accumulation. The present study showed that acute alcohol intoxication caused hepatic lipid accumulation in Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic sterol-regulatory element binding protein (SREBP)-1, a transcription factor regulating fatty acid and triglyceride (TG) synthesis, was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic Fas, Acc, Scd-1 and Dgat-2, the key genes for fatty acid and TG synthesis, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Additional experiment showed that hepatic MyD88 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic NF-κB was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Moreover, hepatic GSH content was reduced and hepatic MDA level was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic CYP2E1 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic p67phox and gp91phox, two NADPH oxidase subunits, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Alpha-phenyl-N-t-butylnitrone (PBN), a free radical spin-trapping agent, protected against alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. In conclusion, Tlr4-mutant mice are resistant to acute alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. PMID:27627966

  18. 2个水稻矮杆突变体的遗传分析%Genetic Analysis of Two Dwarf Mutants of Rice

    薛建峰; 汤永荣; 查仁明; 罗洪发

    2011-01-01

    The aim was to study the genetic development of dwarf mutants of rice. Two dwarf mutants mini-plant (mp) and dwarf multi-tiller, reciprocal crossed with 'Minghui 63' and 'Minghui 86'. By the character investigation and chi-square test, in the F1 generation, two dwarf mutants had recessive heredity. In the F2 segregating population, the number of rice dwarf mutant and wild-type plants, met Mendel's single-genetic laws. Therefore, it confirmed that the two dwarf mutants of rice were controlled by a single autosomal recessive gene, respectively.%为了研究水稻矮杆突变体的遗传规律,通过将2个矮杆突变体mini-plant(mp)和矮蘖丛生突变体分别与‘明恢63’、‘明恢86’等进行正反交杂交组合,经过田间的性状调查与卡方测定,发现F1代中2个矮杆突变体均为隐性遗传,在F2分离群体中,2个矮杆突变体的遗传规律符合孟德尔的常染色体单基因隐性遗传.因此,可以推断2个水稻矮杆突变体都是由常染色体上的隐性单基因控制.

  19. Variations in Carbohydrate and Protein Accumulation among Spikelets at Different Positions Within a Panicle During Rice Grain Filling

    DONG Ming-hui; CHEN Pei-feng; XIE Yu-lin; QIAO Zhong-ying; YANG Jian-chang

    2012-01-01

    The accumulation dynamics of kernel components for spikelets at different positions within a rice panicle were investigated during grain filling to understand the physiological reasons for the variation of grain quality.Two rice cultivars,Yangdao 6 (indica) and Yangjing 9538 (japonica),were field-grown,and the grain filling characters and contents of starch,soluble sugar,and protein of the spikelets at different positions were studied.There were significant differences in matter accumulation among spikelets at different positions during grain filling.The early-flowering spikelets presented dominance over the late-flowering spikelets in initial time and initial rate of accumulation.At the initial and mid filling stages,the contents and the rates of starch and amylose accumulation in spikelets decreased with the flowering sequence,but soluble sugar content (SSC) exhibited the opposite trend.The difference in SSC among the spikelets of Yangjing 9538 was greater than that of Yangdao 6,but amylose content in mature spikelets showed no obvious relationship to their flowering sequence.The crude protein content (CPC) of early-flowering spikelets decreased more rapidly than that of late-flowering ones at the initial filling stage,and CPC in the spikelets on the secondary branch was higher than that on the primary branch,but CPC in early-flowering ones was lower than that in late-flowering across the whole grain filling period.Grain water content (GWC) of early-flowering spikelets decreased more rapidly than that of late-flowering spikelets on the same branch at the initial and mid filling stages,especially for the top grain on each primary branch.The results suggested that poor grain filling of late-flowering spikelets may be attributed to their low biological activity rather than carbohydrate supply limitation.

  20. Generation of transgenic rice lines with reduced contents of multiple potential allergens using a null mutant in combination with an RNA silencing method.

    Wakasa, Yuhya; Hirano, Kana; Urisu, Atsuo; Matsuda, Tsukasa; Takaiwa, Fumio

    2011-12-01

    Rice seed proteins are known to be a causative antigen in some patients with food allergy, especially cereal allergy, with clinical symptoms such as eczema and dermatitis. The α-amylase/trypsin inhibitors (14-16 kDa), α-globulin (26 kDa) and β-glyoxalase I (33 kDa) are regarded as major potential allergens of rice (Oryza sativa L.) seed based on specific recognition by serum IgE from allergy patients. In order to suppress the production of these major allergens in rice grains, a mutant in the 'Koshihikari' background lacking the 26 kDa allergen (GbN-1) was used as a host for RNA silencing. A binary vector harboring two RNA interference (RNAi) gene cassettes for suppression of 14-16 kDa and 33 kDa allergens driven by the 13 kDa and 10 kDa prolamin endosperm-specific promoters, respectively, was introduced into the GbN-1 genome by Agrobacterium-mediated transformation. In the most promising transgenic line, the content of the three potential allergens was remarkably reduced to a very faint level without a change in seed phenotype. IgE binding of 15 patients' sera to the transgenic rice seed mostly deficient in the three major allergens was on average only about 10% that of the control wild-type rice, suggesting that these three accounted for the great majority of rice seed causative allergens recognized by patients' IgE and that the sequential allergen deletion/reduction strategy works in the development of hypo-allergenic rice lines.

  1. Rice tissue accumulation of particular elements is dependent on the plant’s physiology

    The leaves, grain and other parts of a rice plant require mineral nutrients for various metabolic and other physiological functions. Breeders sometimes want to manipulate the element composition of the grain. Nutrient-dense grain, which is primarily seen as a means for improving nutrition in some co...

  2. 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.

  3. The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

    Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

    2017-01-01

    This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

  4. The phenome analysis of mutant alleles in Leucine-Rich Repeat Receptor-Like Kinase genes in rice reveals new potential targets for stress tolerant cereals.

    Dievart, Anne; Perin, Christophe; Hirsch, Judith; Bettembourg, Mathilde; Lanau, Nadège; Artus, Florence; Bureau, Charlotte; Noel, Nicolas; Droc, Gaétan; Peyramard, Matthieu; Pereira, Serge; Courtois, Brigitte; Morel, Jean-Benoit; Guiderdoni, Emmanuel

    2016-01-01

    Plants are constantly exposed to a variety of biotic and abiotic stresses that reduce their fitness and performance. At the molecular level, the perception of extracellular stimuli and the subsequent activation of defense responses require a complex interplay of signaling cascades, in which protein phosphorylation plays a central role. Several studies have shown that some members of the Leucine-Rich Repeat Receptor-Like Kinase (LRR-RLK) family are involved in stress and developmental pathways. We report here a systematic analysis of the role of the members of this gene family by mutant phenotyping in the monocotyledon model plant rice, Oryza sativa. We have then targeted 176 of the ∼320 LRR-RLK genes (55.7%) and genotyped 288 mutant lines. Position of the insertion was confirmed in 128 lines corresponding to 100 LRR-RLK genes (31.6% of the entire family). All mutant lines harboring homozygous insertions have been screened for phenotypes under normal conditions and under various abiotic stresses. Mutant plants have been observed at several stages of growth, from seedlings in Petri dishes to flowering and grain filling under greenhouse conditions. Our results show that 37 of the LRR-RLK rice genes are potential targets for improvement especially in the generation of abiotic stress tolerant cereals.

  5. A three-season field study on the in-situ remediation of Cd-contaminated paddy soil using lime, two industrial by-products, and a low-Cd-accumulation rice cultivar.

    Yan-Bing, He; Dao-You, Huang; Qi-Hong, Zhu; Shuai, Wang; Shou-Long, Liu; Hai-Bo, He; Han-Hua, Zhu; Chao, Xu

    2017-02-01

    To mitigate the serious problem of Cd-contaminated paddy soil, we investigated the remediation potential of combining in-situ immobilization with a low-Cd-accumulation rice cultivar. A three-season field experiment compared the soil pH, available Cd and absorption of Cd by three rice cultivars with different Cd accumulation abilities grown in Cd-contaminated paddy soil amended with lime (L), slag (S), and bagasse (B) alone or in combination. The three amendments applied alone and in combination significantly increased soil pH, reduced available Cd and absorption of Cd by rice with no effect on grain yield. Among these, the LS and LSB treatments reduced the brown rice Cd content by 38.3-69.1% and 58.3-70.9%, respectively, during the three seasons. Combined with planting of a low-Cd-accumulation rice cultivar (Xiang Zaoxian 32) resulted in a Cd content in brown rice that met the contaminant limit (≤0.2mgkg(-1)). However, the grain yield of the low-Cd-accumulation rice cultivar was approximately 30% lower than the other two rice cultivars. Applying LS or LSB as amendments combined with planting a low-Cd-accumulation rice cultivar is recommended for the remediation of Cd-contaminated paddy soil. The selection and breeding of low-Cd-accumulation rice cultivars with high grain production requires further research.

  6. 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.

  7. Influence of iron plaque on uptake and accumulation of Cd by rice (Oryza sativa L.) seedlings grown in soil.

    Liu, Houjun; Zhang, Junling; Christie, Peter; Zhang, Fusuo

    2008-05-15

    Iron plaque is ubiquitously formed on the root surfaces of rice. However, little is known about the role of iron plaque in Cd movement from soil to the plant aboveground parts. A pot experiment was conducted to investigate the influence of iron plaque in Cd uptake and accumulation by rice seedlings in soil. Rice seedlings were pre-cultivated in solution culture for 16 days. Two seedlings were transplanted in a nylon bag containing no substrate but surrounded by soil amended with Fe and Cd combined at rates of 0, 1, or 2 g Fe kg(-1) and 0, 2.0, or 10 mg Cd kg(-1) soil. Fe was added to induce different amounts of iron plaque, and Cd to simulate Cd-polluted soils. Plants were grown for a further 43 days and then harvested. The length of the longest leaf and SPAD values of the newly mature leaves were measured during plant growth. Fe and Cd concentrations were determined in dithionite-citrate-bicarbonate (DCB) soil extracts and in plant roots and shoots. Shoot and root dry weights were significantly affected by Fe supply level but not by added Cd. Root dry weight declined with increasing Fe supply but shoot dry weight decreased at 2 g Fe kg(-1) and increased at 1 g Fe kg(-1) (except at 2 mg Cd kg(-1)). The length of the longest leaf and SPAD values of the newly mature leaves were significantly affected by plant growth stage and added Fe and Cd. Fe tended to diminish the negative effect of Cd on these two parameters. Cd concentrations in DCB extracts increased with increasing Cd and Fe supply. In contrast, external Fe supply markedly reduced shoot and root Cd concentrations and there was generally no significant difference between the two Fe supply levels. Shoot and root Cd concentrations increased with increasing Cd addition. Root Cd concentrations were negatively correlated with root Fe concentrations. The proportion of Cd in DCB extracts was significantly lower than in roots or shoots. The results indicate that enhanced Fe uptake by plants can diminish the negative

  8. 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.

  9. Genetic analysis and gene mapping of leafy head (lhd), a mutant blocking the differentiation of rachis branches in rice (Oryza sativa L.)

    DUAN Yuanlin; MAO Damei; LI Weiming; XUE Yongbiao; WU Weiren; LIU Huaqing; ZHANG Danfeng; ZHOU Yuanchang; PAN Runsheng; LIN Lihui; CHEN Zhiwei; GUAN Huazhong

    2003-01-01

    A rice mutant called leafy head (lhd), in which the differentiation of rachis branches is blocked, was identified in a doubled haploid (DH) population derived through F1 anther culture from a cross between rice (Oryza sativa L.) indica cultivar Gui-630 and japonica cultivar Taiwanjing. The mutant is shorter in plant height, possessing smaller and clumpy leaves, and always stays at the vegetative growth stage. Genetic analysis suggests that lhd is controlled by a single recessive gene, which is temporarily named lhd(t). The phenotype of the mutant suggests that LHD(t) is a key gene controlling the differentiation of rachis branches. In order to map the gene, two F2 populations were constructed by crossing the lhd heterozygote with varieties Minghui-77 (indica) and Jinghua-8 (japonica). In the F2 of lhd heterozygote ( Jinghua-8, some mutant plants appeared as the "medium type", suggesting that the lhd phenotype could be influenced by genetic backgrounds. With the published SSR markers of RM series and additional SSR markers developed by ourselves and using the methods of bulked segregant analysis (BSA) and mutant analysis (with 498 mutant plants in total), LHD(t) gene was mapped onto the distal region of the long arm of chromosome 10. Markers SSR1, RM269, RM258, RM304 and RM171 were located on one side with distances of 6.4, 16.6, 18.4, 22.2 and 26.3 cM to LHD(t); whereas markers SSR4 and SSR5 were on the other side with distances of 0.6 and 2.2 cM to LHD(t). The results will facilitate the positional cloning and functional study of the LHD(t) gene.

  10. 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.

  11. 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

    2007-03-01

    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.

  12. Dynamic changes in the distribution of minerals in relation to phytic acid accumulation during rice seed development.

    Iwai, Toru; Takahashi, Michiko; Oda, Koshiro; Terada, Yasuko; Yoshida, Kaoru T

    2012-12-01

    Phytic acid (inositol hexakisphosphate [InsP(6)]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP(6) contents during seed development. While the InsP(6) content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP(6) and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP(6) and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate.

  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. Production of superoxide from photosystem II-light harvesting complex II supercomplex in STN8 kinase knock-out rice mutants under photoinhibitory illumination.

    Poudyal, Roshan Sharma; Nath, Krishna; Zulfugarov, Ismayil S; Lee, Choon-Hwan

    2016-09-01

    When phosphorylation of Photosystem (PS) II core proteins is blocked in STN8 knock-out mutants of rice (Oryza sativa) under photoinhibitory illumination, the mobilization of PSII supercomplex is prevented. We have previously proposed that more superoxide (O2(-)) is produced from PSII in the mutant (Nath et al., 2013, Plant J. 76, 675-686). Here, we clarify the type and site for the generation of reactive oxygen species (ROS). Using both histochemical and fluorescence probes, we observed that, compared with wild-type (WT) leaves, levels of ROS, including O2(-) and hydrogen peroxide (H2O2), were increased when leaves from mutant plants were illuminated with excess light. However, singlet oxygen production was not enhanced under such conditions. When superoxide dismutase was inhibited, O2(-) production was increased, indicating that it is the initial event prior to H2O2 production. In thylakoids isolated from WT leaves, kinase was active in the presence of ATP, and spectrophotometric analysis of nitrobluetetrazolium absorbance for O2(-) confirmed that PSII-driven superoxide production was greater in the mutant thylakoids than in the WT. This contrast in levels of PSII-driven superoxide production between the mutants and the WT plants was confirmed by conducting protein oxidation assays of PSII particles from osstn8 leaves under strong illumination. Those assays also demonstrated that PSII-LHCII supercomplex proteins were oxidized more in the mutant, thereby implying that PSII particles incur greater damage even though D1 degradation during PSII-supercomplex mobilization is partially blocked in the mutant. These results suggest that O2(-) is the major form of ROS produced in the mutant, and that the damaged PSII in the supercomplex is the primary source of O2(-).

  15. T-DNA插入产生的水稻小粒突变体的遗传分析%Genetic Analysis of a Small Grain Mutant Induced by T-DNA Insertion in Rice

    张向前; 朱海涛; 邹金松; 曾瑞珍

    2008-01-01

    [Objective] The aim of this study is to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice. [Method] On the basis of the collection of T-DNA tag lines, the progeny of homozygous plants carrying T-DNA insertion were screened for mutants with mutated phenotypes. The genetic analysis of the mutant and test for the linkage between the mutated phenotype and the T-DNA insertion were carried out to determine its genetic characteristics. [Result] In the present study, a grain shape mutant induced by T-DNA insertion in rice was identified, which showed small grain. Genetic analysis of the mutant showed that the two types of phenotype, normal and small grain in the segregating populations derived resistance showed that all the mutants were resistant while the normal results indicated that the mutant phenotype cosegregated with Bar gene. The small grain mutant caused by T-DNA insertion was confirmed by PCR amplification aiming at T-DNA. [Conclusion] The grain shape mutant is useful for isolation of the tagged gene and genetic improvement in rice.

  16. Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil

    The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and...

  17. Decreased photosynthesis in the erect panicle 3 (ep3) mutant of rice is associated with reduced stomatal conductance and attenuated guard cell development

    2015-01-01

    The ERECT PANICLE 3 gene of rice encodes a peptide that exhibits more than 50% sequence identity with the Arabidopsis F-box protein HAWAIIAN SKIRT (HWS). Ectopic expression of the Os02g15950 coding sequence, driven by the HWS (At3g61950) promoter, rescued the hws-1 flower phenotype in Arabidopsis confirming that EP3 is a functional orthologue of HWS. In addition to displaying an erect inflorescence phenotype, loss-of-function mutants of Os02g15950 exhibited a decrease in leaf photosynthetic c...

  18. Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations (Oryza sativa L.)

    TANG; Jiabin; (

    2001-01-01

    [1]Xu, Y. B., Shen, Z. T., Diallel analysis of tiller number at different growth stages in rice (Oryza sativa L.), Theoretical and Applied Genetics, 1991, 83(2): 243-249.[2]Wu, W. R., Li, W. M., Tang, D. Z. et al., Time-related mapping of quantitative trait loci underlying tiller number in rice, Genetics, 1999, (151): 297-303.[3]Wu, P., Zhang, G ., Huang, N., Identification of QTLs controlling quantitative characters in rice using RFLP markers, Euphytica, 1996, 89(3): 349-354.[4]Khush, G . S., Breaking the yield frontier of rice, GeoJournal, 1995, 35(3): 329-332.[5]Chen, X., Themnykh, S., Xu, Y. et al., Development of microsatellite framework providing genome-wide coverage in rice (Oryzae sativa L.), Theoretical and Applied Genetics, 1997, 95(4): 553-567.[6]Panaud, O., Chen, X., McCouch, S. R. et al., Development of microsatellite markers and characterization of simple sequence length polymorphisms (SSLPs) in rice (Oryzae sativa L.), Molecular and General Genetics, 1996, (252): 597-607.[7]McCouth, S. R., Kochert, G., Yu, Z. H. et al., Molecular mapping of rice chromosomes, Theoretical and Applied Genetics, 1988, 76: 815-829.[8]Harushima, Y., Yano, M., Shomura, A. et al., A high-density rice genetic linkage map with 2275 markers using a single F2 population, Genetics, 1998, 148: 479-494.[9]Lander, E. S. et al., Mapmaker: An interactive computer for construction primary genetics linkage maps of experimental and natural populations, Genomics, 1987, (1): 174-182.[10]Kinoshita, T., Report of committee on gene symbolization, nomenclature and linkage groups, Rice Genetic Newsletter, 1995, (12): 9-153.

  19. Accumulation of mutant alpha1-antitrypsin Z in the endoplasmic reticulum activates caspases-4 and -12, NFkappaB, and BAP31 but not the unfolded protein response.

    Hidvegi, Tunda; Schmidt, Bela Z; Hale, Pamela; Perlmutter, David H

    2005-11-25

    In alpha(1)-antitrypsin (alpha1AT) deficiency, a polymerogenic mutant form of the secretory glycoprotein alpha1AT, alpha1ATZ, is retained in the endoplasmic reticulum (ER) of liver cells. It is not yet known how this results in liver injury in a subgroup of deficient individuals and how the remainder of deficient individuals escapes liver disease. One possible explanation is that the "susceptible" subgroup is unable to mount the appropriate protective cellular responses. Here we examined the effect of mutant alpha1ATZ on several potential protective signaling pathways by using cell lines with inducible expression of mutant alpha1AT as well as liver from transgenic mice with liver-specific inducible expression of mutant alpha1AT. The results show that ER retention of polymerogenic mutant alpha1ATZ does not result in an unfolded protein response (UPR). The UPR can be induced in the presence of alpha1ATZ by tunicamycin excluding the possibility that the pathway has been disabled. In striking contrast, ER retention of nonpolymerogenic alpha1AT mutants does induce the UPR. These results indicate that the machinery responsible for activation of the UPR can distinguish the physical characteristics of proteins that accumulate in the ER in such a way that it can respond to misfolded but not relatively ordered polymeric structures. Accumulation of mutant alpha1ATZ does activate specific signaling pathways, including caspase-12 in mouse, caspase-4 in human, NFkappaB, and BAP31, a profile that was distinct from that activated by nonpolymerogenic alpha1AT mutants.

  20. Reduced arsenic accumulation in rice (Oryza sativa L.) shoot involves sulfur mediated improved thiol metabolism, antioxidant system and altered arsenic transporters.

    Dixit, Garima; Singh, Amit Pal; Kumar, Amit; Mishra, Seema; Dwivedi, Sanjay; Kumar, Smita; Trivedi, Prabodh Kumar; Pandey, Vivek; Tripathi, Rudra Deo

    2016-02-01

    Arsenic (As) contamination in rice is at alarming level as majority of rice growing regions are As contaminated such as South East Asia. Restricting the As in aerial parts of rice plant may be an effective strategy to reduce As contamination in food chain. Sulfur (S), an essential element for plant growth and development, plays a crucial role in diminishing heavy metal toxicity. Current study is designed to investigate the role of S to mitigate As toxicity in rice under different S regimes. High S (5 mM) treatment resulted in enhanced root As accumulation as well as prevented its entry in to shoot. Results of thiol metabolism indicate that As was complexed in plant roots through enhanced synthesis of phytochelatins. High S treatment also reduced the expression of OsLsi1 and OsLsi2, the potent transporters of As in rice. High S treatment enhanced the activities of antioxidant enzymes and mitigated the As induced oxidative stress. Thus from present study it is evident that proper supply of S nutrition may be helpful in prevention of As accumulation in aerial parts of plant as well as As induced toxicity.

  1. 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.

  2. Variations and constancy of mercury and methylmercury accumulation in rice grown at contaminated paddy field sites in three Provinces of China.

    Li, B; Shi, J B; Wang, X; Meng, M; Huang, L; Qi, X L; He, B; Ye, Z H

    2013-10-01

    Many paddy fields have been contaminated by mercury (Hg) in mining areas of China. In this study, twenty-six rice cultivars and three Hg contaminated paddy fields in different geographic regions were selected for field trials and aimed to investigate the variations and similarities in total Hg (THg) and methylmercury (MeHg) accumulations in brown rice (seeds) across sites. Our results revealed widescale cultivar variation in THg (13-52 ng g(-1) at Wanshan) and MeHg (3.5-23 ng g(-1)) accumulation and %MeHg (17.7-89%) in seeds. The ability to translocate is an important factor in the levels of THg and MeHg in seed. Cultivar tended to stability in THg accumulation across sites. Some cultivars accumulated lower concentrations of both THg and MeHg in seeds at fields seriously contaminated by Hg. Present results suggest that appropriate cultivar selection is a possible way to reduce THg and MeHg accumulation in seeds of rice grown in Hg-contaminated regions.

  3. Rice OsGL1-6 is involved in leaf cuticular wax accumulation and drought resistance.

    Lingyan Zhou

    Full Text Available Cuticular wax is a class of organic compounds that comprises the outermost layer of plant surfaces. Plant cuticular wax, the last barrier of self-defense, plays an important role in plant growth and development. The OsGL1-6 gene, a member of the fatty aldehyde decarbonylase gene family, is highly homologous to Arabidopsis CER1, which is involved in cuticular wax biosynthesis. However, whether OsGL1-6 participates in cuticular wax biosynthesis remains unknown. In this study, an OsGL1-6 antisense-RNA vector driven by its own promoter was constructed and introduced into the rice variety Zhonghua11 by Agrobacterium-mediated transformation to obtain several independent transgenic plants with decreased OsGL1-6 expression. These OsGL1-6 antisense-RNA transgenic plants showed droopy leaves at the booting stage, significantly decreased leaf cuticular wax deposition, thinner cuticle membrane, increased chlorophyll leaching and water loss rates, and enhanced drought sensitivity. The OsGL1-6 gene was constitutively expressed in all examined organs and was very highly expressed in leaf epidermal cells and vascular bundles. The transient expression of OsGL1-6-GFP fusion indicated that OsGL1-6 is localized in the endoplasmic reticulum. Qualitative and quantitative analysis of the wax composition using gas chromatography-mass spectrometry revealed a significantly reduced total cuticular wax load on the leaf blades of the OsGL1-6 antisense-RNA transgenic plants as well as markedly decreased alkane and aldehyde contents. Their primary alcohol contents increased significantly compared with those in the wild type plants, suggesting that OsGL1-6 is associated with the decarbonylation pathways in wax biosynthesis. We propose that OsGL1-6 is involved in the accumulation of leaf cuticular wax and directly impacts drought resistance in rice.

  4. Effect of fly ash application on soil microbial response and heavy metal accumulation in soil and rice plant.

    Nayak, A K; Raja, R; Rao, K S; Shukla, A K; Mohanty, Sangita; Shahid, Mohammad; Tripathi, R; Panda, B B; Bhattacharyya, P; Kumar, Anjani; Lal, B; Sethi, S K; Puri, C; Nayak, D; Swain, C K

    2015-04-01

    Fly ash (FA), a byproduct of coal combustion in thermal power plants, has been considered as a problematic solid waste and its safe disposal is a cause of concern. Several studies proposed that FA can be used as a soil additive; however its effect on microbial response, soil enzymatic activities and heavy metal accumulation in soil and grain of rice (cv. Naveen) to fly ash (FA) application was studied in a pot experiment during dry season 2011 in an Inceptisol. Fly ash was applied at a rate of zero per cent (FS), five per cent (FA5), ten per cent (FA10), twenty per cent (FA20), 40 per cent (FA40) and 100 per cent (FA100) on soil volume basis with nitrogen (N), phosphorus (P) and potassium (K) (40:20:20mg N:P:Kkg(-1) soil) with six replications. Heavy metals contents in soil and plant parts were analysed after harvest of crop. On the other hand, microbial population and soil enzymatic activities were analysed at panicle initiation stage (PI, 65 days after transplanting) of rice. There was no significant change in the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), cadmium (Cd) and chromium (Cr) with application of fly ash up to FA10. However, at FA100 there was significant increase of all metals concentration in soil than other treatments. Microorganisms differed in their response to the rate of FA application. Population of both fungi and actinomycetes decreased with the application of fly ash, while aerobic heterotrophic bacterial population did not change significantly up to FA40. On the other hand, total microbial activity measured in terms of Fluorescein diacetate (FDA) assay, and denitrifiers showed an increased trend up to FA40. However, activities of both alkaline and acid phosphatase were decreased with the application of FA. Application of FA at lower levels (ten to twenty per cent on soil volume basis) in soil enhanced micronutrients content, microbial activities and crop yield.

  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. Photosynthesis Characters of a Rice Mutant, Shuanglimi%水稻突变体Shuanglimi的光合特性

    赵帅鹏; 黄群策; 张书艮; 张时萍

    2013-01-01

    以水稻突变体Shuanglimi为试验材料,对其幼穗处于减数分裂期时剑叶的净光合速率(Pn)、蒸腾速率(Tr)、叶片气孔导度(Gs)、胞间CO2浓度(Ci)、水分利用率(WUE)和羧化效率(CE)、叶绿素含量及剑叶中维管束数目进行了测定和观察.结果表明,Shuanglimi的Pn、WUE和CE较CK分别降低了(71.18±2.08)%,(72.00±2.51)%和(79.33±3.27)%(P<0.01),而其Tr和Ci与CK之间无显著差异.Shuanglimi总叶绿素含量较CK降低,尤其是叶绿素b含量大幅降低.同时,Shuanglimi剑叶中小维管束的数目较CK降低了(18.86±1.97)%(P<0.01),而大维管束中含有3个和4个导管的特异变化数目较CK明显增加.由此可见,Shuanglimi的光合特性差异是其子粒和生殖特性差异形成的原因之一.%A new rice mutant,Shuanglimi,was selected as the experiment material.The photosynthesis of flag leaves including net photosynthesis rate (Pn),transpiration rate (Tr),stomatal conductance (Gs),intercellular CO2 concentration(Ci),water use efficiency (WUE) and carboxylation efficiency (CE) were examined,and the concentration of chlorophyll and the number of vascular bundle were also measured when the spikelet of Shuanglimi was on the meiosis stage.The results showed that Pn,WUE and CE of Shuanglimi decreased by (71.18±2.08)% (P<0.01),(72.00±2.51)% and (79.33±±3.27)% (P<0.01)compared with that of CK respectively,and T,and Ci had no significant difference.The chlorophyll content of Shuanglimi was less that that of CK,particularly,the concentration of chlorophyll b declined substantially.Meanwhile,the number of small vascular bundles in the flag leaves of Shuanglimi reduced by (18.86±1.97)% (P<0.01) compared with that of CK,and the number of big vascular bundles which included 3 or 4 vessels significantly increased.Therefore,it is the one of reasons that the differences of grain and reproduction of Shuanglimi are caused by the difference of photosynthesis characteristic.

  7. 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.

  8. 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.

  9. 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.

  10. Analysis on blast fungus-responsive characters of a flavonoid phytoalexin sakuranetin; accumulation in infected rice leaves, antifungal activity and detoxification by fungus.

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

    2014-08-04

    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 accumulated without HR. Induced expression of a PA biosynthesis gene OsNOMT for naringenin 7-O-methyltransferase was found before accumulation of sakuranetin in both cultivars. The antifungal activity of sakuranetin was considerably higher than that of the major rice diterpenoid PA momilactone A in vitro and in vivo under similar experimental conditions. The decrease and detoxification of sakuranetin were detected in both solid and liquid mycelium cultures, and they took place slower than those of momilactone A. Estimated local concentration of sakuranetin at HR lesions was thought to be effective for fungus restriction, while that at enlarged lesions in susceptible rice was insufficient. These results indicate possible involvement of sakuranetin in blast resistance and its specific relation to blast fungus.

  11. Excess nickel modulates activities of carbohydrate metabolizing enzymes and induces accumulation of sugars by upregulating acid invertase and sucrose synthase in rice seedlings.

    Mishra, Pallavi; Dubey, R S

    2013-02-01

    The effects of increasing concentrations of nickel sulfate, NiSO(4) (200 and 400 μM) in the growth medium on the content of starch and sugars and activity levels of enzymes involved in starch and sugar metabolism were examined in seedlings of the two Indica rice cvs. Malviya-36 and Pant-12. During a 5-20 day growth period of seedlings in sand cultures, with Ni treatment, no definite pattern of alteration in starch level could be observed in the seedlings. In both roots and shoots of the seedlings Ni treatment led to a significant decrease in activities of starch degrading enzymes α-amylase, β-amylase, whereas starch phosphorylase activity increased. The contents of reducing, non-reducing, and total sugars increased in Ni-treated rice seedlings with a concomitant increase in the activities of sucrose degrading enzymes acid invertase and sucrose synthase. However, the activity of sucrose synthesizing enzyme sucrose phosphate synthase declined. These results suggest that Ni toxicity in rice seedlings causes marked perturbation in metabolism of carbohydrates leading to increased accumulation of soluble sugars. Such perturbation could serve as a limiting factor for growth of rice seedlings in Ni polluted environments and accumulating soluble sugars could serve as compatible solutes in the cells under Ni toxicity conditions.

  12. Morphogenesis, Anatomical Observation and Primary Genetic Analysis of a Multi-glume Floral Organ Mutant in Rice

    PAN Cun-hong; LI Ai-hong; Wu Ru; ZHANG Ya-fang; TANG Wen; WU Chang-yin; ZHANG Qi-fa; PAN Xue-biao

    2006-01-01

    A multi-glume (mg) mutant was obtained by screening the T-DNA inserted mutant pool. Anatomical observation revealed that the florets of the mutant showed elongated leafy paleas/lemmas and palea/lemma-like structures, just like multi-glumes. Among the 215 observed florets of the mutant, 14.27% were failed to produce pistil and stamens, 23.72% showed extra floret generated on the same rachilla, while 62.01% consisted of one to nine stamens and one to three pistils in a single floret. On the other hand, in some cases the transparent bulged vesile-like tissue could be observed at the basis of filament. The mutant showed glumaceous lodicules,which prevented the florets from opening in natural conditions, while the absolute male and female sterility was an obvious character of the current mutant. Observation on the process of floral organ morphogenesis by a scanning electron microscopy (SEM) indicated that no phenotype difference in floret primordia was found between the wild-type and the mutant. Meanwhile, for the mutant, the beginning of stamen and pistil primordial differentiation was later than the wild type and the palea/lemma-like structure continued to differentiate after the formation of normal palea and lemma. Furthermore, in the mutant the asymmetrical division of floral primordial caused variation in the number of stamens and pistils. Therefore, the genetic analyses indicated that the mutation phenotype was a recessive trait controlled by a single gene and co-segregated with the T-DNA. Based on the phenotypic characteristics, it could be deduced that the mutant was the result of homeotic conversion from the function of the class E genes in ABCD model.

  13. 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.

  14. Lack of Zn inhibition of Cd accumulation by rice (Oryza sativa L.) supports non-Zn transporter uptake of Cd

    Rice (Oryza sativa L.) grown on Cd contaminated soils has been linked to health problems in subsistence rice farmers in Japan and China. For other crops, normal geogenic Zn inhibits the increased uptake of Cd on contaminated soils. A study was conducted using a multi-chelator buffered nutrient sol...

  15. Decreased photosynthesis in the erect panicle 3 (ep3) mutant of rice is associated with reduced stomatal conductance and attenuated guard cell development.

    Yu, Hongyang; Murchie, Erik H; González-Carranza, Zinnia H; Pyke, Kevin A; Roberts, Jeremy A

    2015-03-01

    The ERECT PANICLE 3 gene of rice encodes a peptide that exhibits more than 50% sequence identity with the Arabidopsis F-box protein HAWAIIAN SKIRT (HWS). Ectopic expression of the Os02g15950 coding sequence, driven by the HWS (At3g61950) promoter, rescued the hws-1 flower phenotype in Arabidopsis confirming that EP3 is a functional orthologue of HWS. In addition to displaying an erect inflorescence phenotype, loss-of-function mutants of Os02g15950 exhibited a decrease in leaf photosynthetic capacity and stomatal conductance. Analysis of a range of physiological and anatomical features related to leaf photosynthesis revealed no alteration in Rubisco content and no notable changes in mesophyll size or arrangement. However, both ep3 mutant plants and transgenic lines that have a T-DNA insertion within the Os02g15950 (EP3) gene exhibit smaller stomatal guard cells compared with their wild-type controls. This anatomical characteristic may account for the observed decrease in leaf photosynthesis and provides evidence that EP3 plays a role in regulating stomatal guard cell development.

  16. 两个水稻叶色突变体的光合特性研究%Characteristics of Photosynthesis in Two Leaf Color Mutants of Rice

    吕典华; 宗学凤; 王三根; 凌英华; 桑贤春; 何光华

    2009-01-01

    Two leaf color mutants, ygl5 and pygl1, were identified from the progeny of Jinhui 10 treated with EMS, and Jinhui 10 was an excellent restorer line bred in the Rice Research Institute of Southwest University. This paper reported their photosynthetic parameters and ultra-structure of chloroplast. Compared with the original parent, both mutants had a decline content of chlorophylls significantly, especially in total chlorophylls for ygl5 and in chlorophyll b for the pygl1. Photosynthetic and chlorophyll fluorescence parameters were determined by L1-6400, the results showed that the net photosynthetic rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s) were higher in the mutants, with higher light compensation point (LCP) and lower light saturation point (LSP) as well as lower CO_2 compensation point (CCP) and CO_2 saturation point (CSP). Compared with Jinhui 10, the mutants displayed less chloroplast grana and higher optional maximal photochemical efficiency of PS II (F_v/F_m)> actual photochemical efficiency of PSII (Φ_(PSII)), and photochemical quenching (q_P), suggesting that the mutants have higher light energy capture and conversion efficiencies as well as the electron transport efficiency.%以恢复系缙恢10号为对照,对它的两个叶色突变体ygl5和pygl1在孕穗期的光合、荧光特性和叶绿体超微结构进行了研究.结果表明,两个突变体叶绿体内基粒数量明显少于对照,叶绿素含量也大幅下降,其中ygl5表现为叶绿索总体缺乏,pygl1表现为叶绿素b严重缺乏;ygl5和pygl1的P_n、光饱和点、光补偿点、暗呼吸速率、表观量子效率和羧化效率都显著高于对照,而CO_2饱和点、CO_2补偿点和光呼吸速率则低于对照;其F_v/F_m、Φ_(PSII)和q_P均显著高于对照,表明突变体ygl5和pygl1具有较高的光能捕获效率和转换效率.

  17. UDP-glucose pyrophosphorylase2 (OsUgp2),a pollen-preferential gene in rice, plays a critical role in starch accumulation during pollen maturation

    MU Hong; KE JianHao; LIU Wei; ZHUANG ChuXiong; YIP WingKin

    2009-01-01

    UDP-glucose pyrophosphorylase (UGPase) is predominantly present and plays significant role in car-bohydrate metabolism in plants. Two homologous UGPase genes, OsUgp1 and OsUgp2, exist in rice genome. OsUgp1 has recently been reported to be essential for callose deposition during pollen mother cell and meiosis stages as well as for seed carbohydrate metabolism. In this study, a full-length cDNA of OsUgp2 was isolated from rice anther. Northern blot and RNA in situ hybridization indicated that the expression of OsUgp2 was preferentially in pollen and developmentally regulated. No tran-scripts were found in leaf, stem, lemma/palea, ripening grain and florets before the uninucleate micro-spore developmental stage, but a large quantity of OsUgp2 mRNA was found in pollen at the binucleate and mature stages. The immunolocalizaUon of OsUgp2 showed a similar expression pattern to that by RNA in situ hybridization. The function of OsUgp2 was investigated by dsRNA-mediated transcriptional gene silencing. The pollen fertility of 16 independent transgenic rice plants was found between 25%and 90%, which was correlated with the amount of OsUgp2 mRNA. The results of morphological changes and starch variation during pollen development in transgenic rice showed that the abnormal feature of pollen development appeared after the uninucleate microspore stage. Starch failed to accu-mulate in pollen and thus led to sterile pollens. These results demonstrated that OsUgp2 is a pol-len-preferential "late gone" and plays a key role during pollen maturation, especially for starch accu-mulation. OsUgp2 complements OsUgpl to fulfill the UGPase's functions necessary for the full processof pollen development.

  18. Nitrogen accumulation and translocation characteristics of direct-seed-ed rice in cold area%寒地直播稻氮素积累与转运特征

    罗盛国; 周婷; 尹宇龙; 王欢; 赵广欣; 王丽娟

    2015-01-01

    采用稻花香2号为试验材料进行田间试验,研究寒地直播稻与移栽稻氮素积累、转运及产量差异.结果表明,在抽穗期施入粒肥能够提高直播稻生育后期叶片含氮量和氮积累量,增强光合生产能力.抽穗后,起垄直播稻和免耕直播稻氮同化量比移栽稻高139.9%(P<0.01)和160.1%(P<0.01),氮同化贡献率比移栽稻高133.3%(P<0.01)和177.8%(P<0.01).直播稻生育后期仍能进行氮积累,抽穗后30 d至成熟期起垄直播稻和免耕直播稻氮素积累量分别为2.17和3.81 kg·hm-2,而移栽稻在抽穗后30 d至成熟期无氮积累.直播稻和移栽稻产量差异不显著.%The paper was conducted using Daohuaxiang2 as tested rice variety to study the difference in N accumulation, translocation and yield between direct-seeded and transplanted rice in cold area. Results showed that top dressing N fertilizer at heading stage improved N content and N accumulation of direct-seed-ed rice at late growth stage and enhanced photosynthetic production capacity. After heading, N assimilation of ridge direct-seeded rice and no-til age direct-seeded rice were 139.9% (P<0.01) and 160.1% (P<0.01) higher than that of transplanted rice, and N assimilation contribution rates were 133.3% (P<0.01) and 177.8%(P<0.01) higher than that of transplanted rice. N accumulation was stil proceeding at the late stage of direct-seeded rice, from 30-day after heading to maturity, the N accumulation of ridge direct-seeded rice and no til age direct-seeded rice were 2.17 and 3.81 kg·hm-2, respectively, but no N accumulation with trans-planted rice. There was no significant difference in yield between direct-seeded rice and transplanted rice.

  19. A relaxed (rel) mutant of Streptomyces coelicolor A3(2) with a missing ribosomal protein lacks the ability to accumulate ppGpp, A-factor and prodigiosin.

    Ochi, K

    1990-12-01

    A relaxed (rel) mutant was found among 70 thiopeptin-resistant isolates of Streptomyces coelicolor A3(2) which arose spontaneously. The ability of the rel mutant to accumulate ppGpp during Casamino acid deprivation was reduced 10-fold compared to the wild-type. Analysis of the ribosomal proteins by two-dimensional PAGE revealed that the mutant lacked a ribosomal protein, tentatively designated ST-L11. It was therefore classified as a relC mutant. The mutant was defective in producing A-factor and the pigmented antibiotic prodigiosin, in both liquid and agar cultures, but produced agarase normally. Production of actinorhodin, another pigmented antibiotic, was also abnormal; it appeared suddenly in agar cultures after 10 d incubation. Although aerial mycelium still formed, its appearance was markedly delayed. Whereas liquid cultures of the parent strain accumulated ppGpp, agar cultures accumulated only trace amounts. Instead, a substance characterized only as an unidentified HPLC peak accumulated intracellularly in the late growth phase, just before aerial mycelium formation and antibiotic production. This substance did not accumulate in mutant cells. It was found in S. lividans 66 and S. parvulus, but not in seven other Streptomyces species tested. The significance of these observations, and the relationship of the mutant to earlier rel isolates of Streptomyces is discussed.

  20. Production and Accumulation of Xylooligosaccharides with Long Chains by Growing Culture and Xylanase of a Mutant Strain of Bacillus pumilus X-6-19

    Qingzhu Yuan; Tsuyoshi Adachi; Shinji Takenaka; Shuichiro Murakami; Machiko Tanaka; Kenji Aoki

    2008-01-01

    Bacillus pumilus X-6-9 isolated from soil and subsequently identified, produced xylooligosacchatides with long chainsfrom xylan and accumulated them in the culture. By improving the culture conditions and mutating the bacterium, a 3.2-fold increasein the production of the xylooligosaccharides was established, when compared to the original culture conditions of B. pumilus X-6-19.The addition of D-glucose to the culture of the mutant swain U-3 of B. pumilus X-6-9 repressed the synthesis of β-xylosidase, but notxylanase. Thus, it was revealed that strain U-3 was a good organism for the production and accumulation of xylooligosaccharideswith long chains from xylan by a microbial culture. Xylanase produced by strain U-3 was purified to homogeneity and characterized.The hydrolyzates generated by the purified xylanase contained xylobiose, xylotrinse, xylotewaose, and xylopentaose, but not xylose.

  1. Chemical chaperone treatment reduces intracellular accumulation of mutant collagen IV and ameliorates the cellular phenotype of a COL4A2 mutation that causes haemorrhagic stroke.

    Murray, Lydia S; Lu, Yinhui; Taggart, Aislynn; Van Regemorter, Nicole; Vilain, Catheline; Abramowicz, Marc; Kadler, Karl E; Van Agtmael, Tom

    2014-01-15

    Haemorrhagic stroke accounts for ∼20% of stroke cases and porencephaly is a clinical consequence of perinatal cerebral haemorrhaging. Here, we report the identification of a novel dominant G702D mutation in the collagen domain of COL4A2 (collagen IV alpha chain 2) in a family displaying porencephaly with reduced penetrance. COL4A2 is the obligatory protein partner of COL4A1 but in contrast to most COL4A1 mutations, the COL4A2 mutation does not lead to eye or kidney disease. Analysis of dermal biopsies from a patient and his unaffected father, who also carries the mutation, revealed that both display basement membrane (BM) defects. Intriguingly, defective collagen IV incorporation into the dermal BM was observed in the patient only and was associated with endoplasmic reticulum (ER) retention of COL4A2 in primary dermal fibroblasts. This intracellular accumulation led to ER stress, unfolded protein response activation, reduced cell proliferation and increased apoptosis. Interestingly, the absence of ER retention of COL4A2 and ER stress in cells from the unaffected father indicate that accumulation and/or clearance of mutant COL4A2 from the ER may be a critical modifier for disease development. Our analysis also revealed that mutant collagen IV is degraded via the proteasome. Importantly, treatment of patient cells with a chemical chaperone decreased intracellular COL4A2 levels, ER stress and apoptosis, demonstrating that reducing intracellular collagen accumulation can ameliorate the cellular phenotype of COL4A2 mutations. Importantly, these data highlight that manipulation of chaperone levels, intracellular collagen accumulation and ER stress are potential therapeutic options for collagen IV diseases including haemorrhagic stroke.

  2. alpha,omega-Dicarboxylic acid accumulation by acyl-CoA oxidase deficient mutants of Yarrowia lipolytica.

    Smit, Martha S; Mokgoro, Masego M; Setati, Evodia; Nicaud, Jean-Marc

    2005-06-01

    alpha,omega-Dicarboxylic acid accumulation from alkanes and alkane degradation intermediates was investigated using Yarrowia lipolytica wild type strain W29 as well as a double, a triple and a quadruple POX-deleted strains. Six genes, POX1 through POX6, encode six acyl-CoA oxidase isozymes in Y. lipolytica. All the strains accumulated dodecanedioic acid (5-20 mg ml(-1)) from the diterminal functionalised 1,12-dodecane diol and 12-hydroxdodecanoic acid. The quadruple-deleted strain was the only strain that was able to accumulate dioic acids from C16 alkanol and monocarboxylic acid as well as from C12, C14 and C16 alkanes (maximum 8 mg ml(-1) from dodecane).

  3. Transcriptional activation of a MYB gene controls the tissue-specific anthocyanin accumulation in a purple cauliflower mutant

    Flavonoids such as anthocyanins possess significant health benefits to humans and play important physiological roles in plants. An interesting Purple gene mutation in cauliflower confers an abnormal pattern of anthocyanin accumulation, giving intense purple color in very young leaves, curds, and see...

  4. Calvin cycle mutants of photoheterotrophic purple nonsulfur bacteria fail to grow due to an electron imbalance rather than toxic metabolite accumulation.

    Gordon, Gina C; McKinlay, James B

    2014-03-01

    Purple nonsulfur bacteria grow photoheterotrophically by using light for energy and organic compounds for carbon and electrons. Disrupting the activity of the CO2-fixing Calvin cycle enzyme, ribulose 1,5-bisphosphate carboxylase (RubisCO), prevents photoheterotrophic growth unless an electron acceptor is provided or if cells can dispose of electrons as H2. Such observations led to the long-standing model wherein the Calvin cycle is necessary during photoheterotrophic growth to maintain a pool of oxidized electron carriers. This model was recently challenged with an alternative model wherein disrupting RubisCO activity prevents photoheterotrophic growth due to the accumulation of toxic ribulose-1,5-bisphosphate (RuBP) (D. Wang, Y. Zhang, E. L. Pohlmann, J. Li, and G. P. Roberts, J. Bacteriol. 193:3293-3303, 2011, http://dx.doi.org/10.1128/JB.00265-11). Here, we confirm that RuBP accumulation can impede the growth of Rhodospirillum rubrum (Rs. rubrum) and Rhodopseudomonas palustris (Rp. palustris) RubisCO-deficient (ΔRubisCO) mutants under conditions where electron carrier oxidation is coupled to H2 production. However, we also demonstrate that Rs. rubrum and Rp. palustris Calvin cycle phosphoribulokinase mutants that cannot produce RuBP cannot grow photoheterotrophically on succinate unless an electron acceptor is provided or H2 production is permitted. Thus, the Calvin cycle is still needed to oxidize electron carriers even in the absence of toxic RuBP. Surprisingly, Calvin cycle mutants of Rs. rubrum, but not of Rp. palustris, grew photoheterotrophically on malate without electron acceptors or H2 production. The mechanism by which Rs. rubrum grows under these conditions remains to be elucidated.

  5. Characterization of Gibberellin Receptor Mutants of Barley (Hordeum vulgare L.)

    Peter M.Chandler; Carol A.Harding; Anthony R.Ashton; Mark D.Mulcair; Nicholas E.Dixon; Lewis N.Mander

    2008-01-01

    The sequence of Gidl (a gene for a gibberellin (GA) receptor from rice) was used to identify a putative orthoIogue from barley.This was expressed in E.coil,and produced a protein that was able to bind GA in vitro with both structural specificity and saturability.Its potential role in GA responses was investigated using barley mutants with reduced GA sensitivity (gsel mutants).Sixteen different gsel mutants each carried a unique nucleotide substitution in this sequence.In all but one case,these changes resulted in single amino acid substitutions,and,for the remaining mutant,a substitution in the 5' untranslated region of the mRNA is proposed to interfere with translation initiation.There was perfect linkage in segregating populations between new mutant alleles and the gsel phenotype,leading to the conclusion that the putative GID1 GA receptor sequence in barley corresponds to the Gsel locus.Determination of endogenous GA contents in one of the mutants revealed enhanced accumulation of bioactive GA1,and a deficit of C20 GA precursors.All of the gsel mutants had reduced sensitivity to exogenous GA3,and to AC94377 (a GA analogue) at concentrations that are normally 'saturating',but,at much higher concentrations,there was often a considerable response.The comparison between barley and rice mutants reveals interesting differences between these two cereal species in GA hormonal physiology.

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

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

    2011-01-01

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

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

    Wu, Chun-yong; Feng, Ying; Shohag, Md Jahidul Islam; Lu, Ling-li; Wei, Yan-yan; Gao, Chong; Yang, Xiao-e

    2011-05-01

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

  8. Understanding the paradox of selenium contamination in mercury mining areas: high soil content and low accumulation in rice.

    Zhang, Hua; Feng, Xinbin; Jiang, Chengxin; Li, Qiuhua; Liu, Yi; Gu, Chunhao; Shang, Lihai; Li, Ping; Lin, Yan; Larssen, Thorjørn

    2014-05-01

    Rice is an important source of Se for billions of people throughout the world. The Wanshan area can be categorized as a seleniferous region due to its high soil Se content, but the Se content in the rice in Wanshan is much lower than that from typical seleniferous regions with an equivalent soil Se level. To investigate why the Se bioaccumulation in Wanshan is low, we measured the soil Se speciation using a sequential partial dissolution technique. The results demonstrated that the bioavailable species only accounted for a small proportion of the total Se in the soils from Wanshan, a much lower quantity than that found in the seleniferous regions. The potential mechanisms may be associated with the existence of Hg contamination, which is likely related to the formation of an inert Hg-Se insoluble precipitate in soils in Wanshan.

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

    Yushi Ye

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

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

    Arun S.K. Shunmugam

    2014-12-01

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

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

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

    2016-07-01

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

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

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

    2016-01-01

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

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

    Pankaj Kumar Verma

    2016-06-01

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

  14. Studies on Biological Characterization of Rice Brittle Culm Mutants and Their Biomass Degradation Efficiency%特异水稻脆茎突变体生物学特性及生物质降解效率的研究

    冯永清; 邹维华; 李丰成; 张晶; 张会; 谢国生; 涂媛苑; 路铁刚; 彭良才

    2013-01-01

      水稻脆茎突变体是一种重要的种质资源。为研究该突变体在能源作物培育中的利用潜力,比较分析了10个突变体及其野生型品种日本晴(NPB)在物理特性、细胞壁组成、农艺性状、生物质降解效率等方面的差异。结果表明:水稻脆茎突变体生长发育正常,但茎秆抗张力和株高低于 NPB;茎秆细胞壁纤维素含量降低,半纤维素含量增高,木质素含量增加不显著。细胞壁合成关键基因转录水平的变化与细胞壁组成一致。此外,水稻脆茎突变体的单株穗重与 NPB 差异不显著,有效穗数增加,生物质产量增加,抗倒伏性显著增强,秸秆易粉碎且在酸、碱预处理及纤维素复合酶酶解条件下的产糖量及纤维素降解效率显著高于 NPB。这些特异水稻脆茎突变体的表型优势揭示出其在水稻秸秆利用中的应用潜力,它们可以用于高产、生物质高效降解水稻品种的培育。%  Brittle culm mutants are considered as valuable germplasm resources for energy crop breeding in rice. This study analyzed biological characters and biomass digestibilities of 10 distinct rice brittle culm mutants. Compared with the wild type japonical variety NPB ( Nipponbare), all mutants displayed normal growth and development, and shorter plant height and lower tension stress. In terms of cell wall composition in the mature culm tissues, the mutants showed lower cellulose and higher hemicelluloses levels than that of the NPB and no significant increase is identified in lignin level, which were consistent with the RNA transcript levels of their major wall polymer synthases. Due to cell wall alternation, the rice mutants appeared to have a stronger resistance to lodging than NPB did. However, all mutants and NPB were determined with unchanged single plant spike weight and higher number of effective panicles, suggesting that the mutants were not much affected with their seed

  15. Jasmonic acid accumulation and systemic photosynthetic and electrical changes in locally burned wild type tomato, ABA-deficient sitiens mutants and sitiens pre-treated by ABA.

    Hlavinka, Jan; Nožková-Hlaváčková, Vladimíra; Floková, Kristýna; Novák, Ondřej; Nauš, Jan

    2012-05-01

    Burning the terminal leaflet of younger tomato (Lycopersicon esculentum Mill.) leaf caused local and systemic changes in the surface electrical potential (SEP) and gas exchange (GE) parameters. The local and systemic accumulation of endogenous abscisic acid (ABA) and jasmonic acid (JA) was measured 85 min after burning. The experiments were conducted with wild type (WT) plants, ABA-deficient mutant sitiens (SIT) and ABA pre-treated SIT plants (SITA). First changes in SEP were detected within 1.5 min after burning and were followed by a decrease in GE parameters within 3-6 min in WT, SIT and SITA plants. GE and SEP time courses of SIT were different and wave amplitudes of SEP of SIT were lower compared to WT and SITA. ABA content in WT and SITA control plants was similar and substantially higher compared to SIT, JA content was similar among WT, SIT and SITA. While changes in the ABA content in systemic leaves have not been recorded after burning, the systemic JA content was substantially increased in WT and more in SIT and SITA. The results suggest that ABA content governs the systemic reaction of GE and the SEP shape upon local burning. ABA, JA and SEP participate in triggering the GE reaction. The ABA shortage in the SIT in the reaction to burning is partly compensated by an enhanced JA accumulation. This JA compensation is maintained even in SIT endogenously supplied with ABA. A correlation between the systemic JA content and changes in GE parameters or SEP was not found.

  16. Cd在水稻籽粒中的积累及运输机制%Mechanisms of Cd Accumulation and Transportation in Rice Grain

    叶瑶瑶; 王飞娟; 石晓柳; 王高阳; 俞姣; 朱诚

    2012-01-01

    Cadmium was one of the most toxic heavy metal elements,and it had very strong activity in the environment and strong ability of migration in the soil-plant system.Plant could accumulate high level of cadmium,and enter human body through the food chain ,chen cause health problems.The progress on mechanisms of Cd accumulation and transportation in rice was reviewed,including root absorption ,upward transportation adjusted by xylem,transportation to grain adjusted by phloem and so on.%Cd是毒性最大的重金属之一,在环境中的活性与在土壤一植物系统中的迁移能力都很强植物能积累较高浓度的Cd,并通过食物链进入人体引起人体的疾病.综述了Cd在水稻中的积累及运输机制的研究进展,包括根的吸收、木质部调节向上运输及韧皮部调节向籽粒中转运等方面

  17. MutMap-Gap: whole-genome resequencing of mutant F2 progeny bulk combined with de novo assembly of gap regions identifies the rice blast resistance gene Pii.

    Takagi, Hiroki; Uemura, Aiko; Yaegashi, Hiroki; Tamiru, Muluneh; Abe, Akira; Mitsuoka, Chikako; Utsushi, Hiroe; Natsume, Satoshi; Kanzaki, Hiroyuki; Matsumura, Hideo; Saitoh, Hiromasa; Yoshida, Kentaro; Cano, Liliana M; Kamoun, Sophien; Terauchi, Ryohei

    2013-10-01

    Next-generation sequencing allows the identification of mutations responsible for mutant phenotypes by whole-genome resequencing and alignment to a reference genome. However, when the resequenced cultivar/line displays significant structural variation from the reference genome, mutations in the genome regions missing from the reference (gaps) cannot be identified by simple alignment. Here we report on a method called 'MutMap-Gap', which involves delineating a candidate region harboring a mutation of interest using the recently reported MutMap method, followed by de novo assembly, alignment, and identification of the mutation within genome gaps. We applied MutMap-Gap to isolate the blast resistant gene Pii from the rice cv Hitomebore using mutant lines that have lost Pii function. MutMap-Gap should prove useful for cloning genes that exhibit significant structural variations such as disease resistance genes of the nucleotide-binding site-leucine rich repeat (NBS-LRR) class.

  18. Genetic and field management strategies to enhance the nutritional value of rice grains and limit accumulation of undesirable elements such as arsenic

    Enhancing the nutritional value of rice grains is of particular interest because rice is a primary dietary component for more than half of the world’s population, and is a primary source of nutrients in many underdeveloped countries. Because rice can be grown under both flooded and unflooded field ...

  19. Hydraulic conductance as well as nitrogen accumulation plays a role in the higher rate of leaf photosynthesis of the most productive variety of rice in Japan.

    Taylaran, Renante D; Adachi, Shunsuke; Ookawa, Taiichiro; Usuda, Hideaki; Hirasawa, Tadashi

    2011-07-01

    An indica variety Takanari is known as one of the most productive rice varieties in Japan and consistently produces 20-30% heavier dry matter during ripening than Japanese commercial varieties in the field. The higher rate of photosynthesis of individual leaves during ripening has been recognized in Takanari. By using pot-grown plants under conditions of minimal mutual shading, it was confirmed that the higher rate of leaf photosynthesis is responsible for the higher dry matter production after heading in Takanari as compared with a japonica variety, Koshihikari. The rate of leaf photosynthesis and shoot dry weight became larger in Takanari after the panicle formation and heading stages, respectively, than in Koshihikari. Roots grew rapidly in the panicle formation stage until heading in Takanari compared with Koshihikari. The higher rate of leaf photosynthesis in Takanari resulted not only from the higher content of leaf nitrogen, which was caused by its elevated capacity for nitrogen accumulation, but also from higher stomatal conductance. When measured under light-saturated conditions, stomatal conductance was already decreased due to the reduction in leaf water potential in Koshihikari even under conditions of a relatively small difference in leaf-air vapour pressure difference. In contrast, the higher stomatal conductance was supported by the maintenance of higher leaf water potential through the higher hydraulic conductance in Takanari with the larger area of root surface. However, no increase in root hydraulic conductivity was expected in Takanari. The larger root surface area of Takanari might be a target trait in future rice breeding for increasing dry matter production.

  20. Mutant p53 accumulation in human breast cancer is not an intrinsic property or dependent on structural or functional disruption but is regulated by exogenous stress and receptor status.

    Bouchalova, Pavla; Nenutil, Rudolf; Muller, Petr; Hrstka, Roman; Appleyard, M Virginia; Murray, Karen; Jordan, Lee B; Purdie, Colin A; Quinlan, Philip; Thompson, Alastair M; Vojtesek, Borivoj; Coates, Philip J

    2014-07-01

    Many human cancers contain missense TP53 mutations that result in p53 protein accumulation. Although generally considered as a single class of mutations that abrogate wild-type function, individual TP53 mutations may have specific properties and prognostic effects. Tumours that contain missense TP53 mutations show variable p53 stabilization patterns, which may reflect the specific mutation and/or aspects of tumour biology. We used immunohistochemistry on cell lines and human breast cancers with known TP53 missense mutations and assessed the effects of each mutation with four structure-function prediction methods. Cell lines with missense TP53 mutations show variable percentages of cells with p53 stabilization under normal growth conditions, ranging from approximately 50% to almost 100%. Stabilization is not related to structural or functional disruption, but agents that stabilize wild-type p53 increase the percentages of cells showing missense mutant p53 accumulation in cell lines with heterogeneous stabilization. The same heterogeneity of p53 stabilization occurs in primary breast cancers, independent of the effect of the mutation on structural properties or functional disruption. Heterogeneous accumulation is more common in steroid receptor-positive or HER2-positive breast cancers and cell lines than in triple-negative samples. Immunohistochemcal staining patterns associate with Mdm2 levels, proliferation, grade and overall survival, whilst the type of mutation reflects downstream target activity. Inhibiting Mdm2 activity increases the extent of p53 stabilization in some, but not all, breast cancer cell lines. The data indicate that missense mutant p53 stabilization is a complex and variable process in human breast cancers that associates with disease characteristics but is unrelated to structural or functional properties. That agents which stabilize wild-type p53 also stabilize mutant p53 has implications for patients with heterogeneous mutant p53 accumulation

  1. 水稻窄卷叶突变体 nrl(t)的遗传分析与基因定位%Genetic Analysis and Gene Mapping of a Narrow and Rolled Mutant nrl(t) in Rice

    陈涛; 王才林; 刘燕清; 张亚东; 朱镇; 赵庆勇; 周丽慧; 姚姝; 于新; 赵凌

    2014-01-01

    为发掘、定位和克隆水稻窄卷叶相关突变基因,揭示叶片发育机理。对武运粳7号条纹叶枯病抗性改良品系中发现的窄卷叶突变体进行了表型观察、遗传分析及基因定位。结果表明,与野生型相比,突变体在叶片形态发生改变的同时,其株高、分蘖性、穗长、枝梗数、每穗实粒数、穗粒数、结实率、千粒质量等农艺性状也存在显著差异。遗传分析表明,该突变性状受一对隐性基因控制。以500株辐恢838/nrl(t)的F2隐性单株为定位群体,利用SSR标记将NRL(t)基因定位于水稻第11染色体短臂末端RM11-01、RM11-11之间,物理距离约为160 kb的范围内。通过水稻基因组注释数据库分析发现,在该区域存在26个预测的基因,测序分析表明已报道的homeobox3A基因可能是潜在的候选基因,这为进一步研究该基因奠定了基础。%Leaf morphology is one of key components for rice plant architecture , so excavation , mapping and cloning related mutant genes are very important for revealing mechanism of leaf development and breeding new rice varieties with ideotype and super-high yield.In this study,the narrow and rolled mutant ntl (t) was found from the im-proved line of rice stripe disease for Wuyunjing No .7 and the mutant phenotype genetic analysis and gene mapping was researched .Compared with wild type , the mutant showed multipe abnormal phenotypes , such as shorter leaf length and width,rolled leaf,dwarfism,more tillers,reduced panicle length,branch number,filled grain number per spike ,spikelets per spike , seed-setting rate and 1000-grain weight .Genetic analysis indicated that the mutant was controlled by a single recessive gene .Using 500 recessive mutant individuals in the F 2 population derived from the cross between Fuhui 838 and nrl(t) ,the gene NRL(t) was located to a confined region of 160 kb flanked by two mic-rosatellite markers RM11-01 and RM11-11 on the

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

    Jamil, Muhammad

    2013-02-01

    Full Text Available The exogenous application of plant derived smoke solution through seed pre treatment is consider to create tolerance in the plant against salinity, for this purpose different dilution of plant derived smoke solution as 1:5000 Buhania, 1:1000 Buhania, 1:1000 Cymbopogon, 1:500 Cymbopogon were used against 0 mM, 50, 100 and 150mM NaCl solution in the medium. The effect was observed on total proline accumulation, heavy metals uptake, photosynthetic pigments and protein polypeptide bands intensity in two rice varieties as Basmati 385 (B-385 and Shaheen Basmati (S. Basmati. Proline concentration increases while chlorophyll “a” chlorophyll “b” and carotene level decreases with increasing salinity. On other hand zinc concentration increases while cadmium and lead concentration decrease in the crop under saline conditions. Intensity of protein polypeptides bands decreases gradually with increasing salinity level but plants from the seeds soaked with smoke solution alleviate the drastic affect of salinity, and intensity of bands is quite good by comparing with non primed seeds. It is concluded that seed priming with plant derived smoke solution show beneficial effect on crop to protect them from salinity.

  3. High Photosynthetic Efficiency of Leaf Colour Mutant of Rice (Oryza sativa L.)%水稻叶色突变体的高光合特性

    欧立军

    2011-01-01

    标810S是温敏核不育系810S中的淡黄绿叶自然突变株,具有较高的光合速率.本文对突变体的光合色素、光合速率、荧光参数和光合关键酶活性等研究发现,标810S光合色素约为810S的一半,强光条件下标810S光合速率(Pn)比对照高,且没有明显的“午休”现象.标810S气孔导度(Gs)显著增加,叶绿素荧光动力学参数显示,标810S光量子转化效率高;光合酶1,5一二磷酸核酮糖羧化酶(RuBPCase)活性是对照的69.80%,磷酸烯醇式丙酮酸羧化酶(PEPCase)和NADP-苹果酸酶(NADH-ME)却比810S分别上升79.50%和69.06%.研究结果认为,光合色素含量下降是标810S叶片呈淡黄绿叶色的根本原因.突变体通过减少热耗散和提高光合电子传递速率来提高光能利用效率,为暗反应提供足够的同化力,而较高的PEPC活性和较大的气孔导度使其能更有效地固定C02,光反应和暗反应的协同使突变体具有较高的光合速率.%Biao 810S is a yellow-green leaf mutant of the thermosensitive genie male sterile (TGMS) rice which has higher photosynthetic rate. The photosynthetic characteristics of Biao 810S were studied with the wild type TGMS line 810S as a control to clarify the physiological basis of high photosynthetic efficiency and provide a theoretical basis for further utilization. The photosynthetic pigment, photosynthetic rate, fluorescence parameters and activity of photosynthetic key enzyme were measured. The content of photosynthetic pigment in Biao 810S was approximately half of that in 810S. However, the net photosynthetic rate of Biao 810S was higher than that of 810S under high intensity light and Biao 810S had no obvious "Midday depression" phenomenon. The stomatal conductance of Biao 810S was highly increased and the light quantum transformation efficiency was higher than that of 810S. The activity of ribulose-l,5-bisphosphate carboxylase (RuBPCase) in Biao 810S was 69.80% of that in 810S, but the

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

    LI Tian; Ryu OHSUGI; Tohru YAMAGISHI; Haruto SASAKI

    2006-01-01

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

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

    Soundararajan, Ramani; Won, Jungyeon; Stearns, Timothy M; Charette, Jeremy R; Hicks, Wanda L; Collin, Gayle B; Naggert, Jürgen K; Krebs, Mark P; Nishina, Patsy M

    2014-01-01

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

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

    Ramani Soundararajan

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

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

    徐向华; 刘传平; 唐新莲; 雷静; 顾明华; 李芳柏

    2014-01-01

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

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

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

    2014-01-01

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

  9. 水稻淡褐斑叶突变体lbsll的遗传分析与基因定位%Genetic Analysis and Gene Mapping of a Light Brown Spotted Leaf Mutant in Rice

    奉保华; 杨杨; 施勇烽; 林璐; 陈洁; 黄奇娜; 魏彦林; Hei LEUNG; 吴建利

    2012-01-01

    A light brown spotted-leaf mutant of rice was isolated from an EMS-induced IR64 mutant bank. The mutant, designated as lbs.ll (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, 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 termed lbsll (t), which was mapped to the short arm of chromosome 6. With developed SSR markers, the gene was finally delimited to an interval of 130 kb between markers RM586 and RM588. The Ibsll (t) gene is likely a novel rice spotted-leaf gene since no other similar genes have been i-dentified near the chromosomal region. The genetic data and recombination populations provided will facilitate further fine-mapping and cloning of the gene.%通过EMS诱变籼稻品种IR64获得一个稳定遗传的淡褐色斑点叶突变体lbsll(light broun spotted leaf1).在自然条件下,突变体播种后10~14 d,叶片上出现淡褐色斑点,随后逐渐扩散至全叶,第1叶至剑叶上均有淡褐色斑,为全生育期性状.斑点性状的表达对株高、生育期、结实率和千粒重等农艺性状具有显著的影响.遗传分析结果表明,该淡褐色斑点叶性状受一个隐性核基因控制.将突变体lbsll与正常叶色水稻Morobereken杂交构建F2定化群体,利用SSR标记,最终将该淡褐叶基因lbsll(t)定位在第6染色体短臂上一个约130 kb的区段上.定位的结果和发展的群体为该基因的进一步精细定位和克隆奠定了基础.

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

    Yumiko Yoshizaki

    2014-08-01

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

  11. Effects of silicon (Si) on arsenic (As) accumulation and speciation in rice (Oryza sativa L.) genotypes with different radial oxygen loss (ROL).

    Wu, Chuan; Zou, Qi; Xue, Shengguo; Mo, Jingyu; Pan, Weisong; Lou, Laiqing; Wong, Ming Hung

    2015-11-01

    Arsenic (As) contamination of paddy soils has adversely affected the health of millions of people those consuming rice for staple food. The present study was aimed at investigating the effects of silicon (Si) fertilization on As uptake, speciation in rice plants with different radial oxygen loss (ROL). Six genotypes were planted in pot soils under greenhouse conditions until late tillering state. The results showed that the rates of ROL were higher in hybrid rice genotypes varying from 19.76 to 27 μmol O2 g(-1) root dry weight h(-1) than that in conventional indica rice genotypes varying from 9.55 to 15.41 μmol O2 g(-1) root dry weight h(-1). Si addition significantly increased straw biomass (price efficiently by combining Si fertilization and selecting genotypes with high radial oxygen loss.

  12. Genetic manipulation of the γ-aminobutyric acid (GABA) shunt in rice: overexpression of truncated glutamate decarboxylase (GAD2) and knockdown of γ-aminobutyric acid transaminase (GABA-T) lead to sustained and high levels of GABA accumulation in rice kernels.

    Shimajiri, Yasuka; Oonishi, Takayuki; Ozaki, Kae; Kainou, Kumiko; Akama, Kazuhito

    2013-06-01

    Gamma-aminobutyric acid (GABA) is a non-protein amino acid commonly present in all organisms. Because cellular levels of GABA in plants are mainly regulated by synthesis (glutamate decarboxylase, GAD) and catabolism (GABA-transaminase, GABA-T), we attempted seed-specific manipulation of the GABA shunt to achieve stable GABA accumulation in rice. A truncated GAD2 sequence, one of five GAD genes, controlled by the glutelin (GluB-1) or rice embryo globulin promoters (REG) and GABA-T-based trigger sequences in RNA interference (RNAi) cassettes controlled by one of these promoters as well, was introduced into rice (cv. Koshihikari) to establish stable transgenic lines under herbicide selection using pyriminobac. T₁ and T₂ generations of rice lines displayed high GABA concentrations (2-100 mg/100 g grain). In analyses of two selected lines from the T₃ generation, there was a strong correlation between GABA level and the expression of truncated GAD2, whereas the inhibitory effect of GABA-T expression was relatively weak. In these two lines both with two T-DNA copies, their starch, amylose, and protein levels were slightly lower than non-transformed cv. Koshihikari. Free amino acid analysis of mature kernels of these lines demonstrated elevated levels of GABA (75-350 mg/100 g polished rice) and also high levels of several amino acids, such as Ala, Ser, and Val. Because these lines of seeds could sustain their GABA content after harvest (up to 6 months), the strategy in this study could lead to the accumulation GABA and for these to be sustained in the edible parts.

  13. Effect of atmospheric mercury deposition on selenium accumulation in rice (Oryza sativa L.) at a mercury mining region in southwestern China.

    Zhang, Chao; Qiu, Guangle; Anderson, Christopher W N; Zhang, Hua; Meng, Bo; Liang, Liang; Feng, Xinbin

    2015-03-17

    Selenium (Se) is an important trace element for human nutrition and has an interactive effect on mercury (Hg) uptake by plants and Hg toxicity in animals. Rice (Oryza sativa L.) is the dominant source of dietary Se in China, however the effect of soil Hg contamination on the Se concentration in rice is unknown. We collected 29 whole rice plant samples and corresponding soils from an active artisanal mercury mining area and an abandoned commercial mercury mining area. The soil Se concentration was similar across the two mining areas and greater than the background concentration for China. However, the Se concentration in rice grain was dramatically different (artisanal area 51±3 ng g(-1); abandoned area 235±99 ng g(-1)). The total gaseous mercury (TGM) concentration in ambient air at the artisanal mining site was significantly greater than at the abandoned area (231 and 34 ng m(-3), respectively) and we found a negative correlation between TGM and the Se concentration in grain for the artisanal area. Principal component analysis indicated that the source of Se in rice was the atmosphere for the artisanal area (no contribution from soil), and both the atmosphere and soil for the abandoned area. We propose that TGM falls to soil and reacts with Se, inhibiting the translocation of Se to rice grain. Our data suggest that Se intake by the artisanal mining community is insufficient to meet Se dietary requirements, predisposing this community to greater risk from Hg poisoning.

  14. Changes of carbohydrate and protein metabolism in seedling leaves of a temperature-induced greenable albino mutant line W25 of rice

    WU; SHUQingyao; XIAYingwu

    1998-01-01

    W25 is a low-temperature sensitive albino mutant line, Temperature not only controls the albino phenotype expression of W2o, but also determines whether it could survive, When the temperature is lower than 25℃. the leaves of W25 shows complete albino, but they exhibits normal green when temperature is higher than 30℃

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

    宋鹏慧; 方玉凤; 王晓燕; 庞荔丹; 戴建军

    2015-01-01

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

  16. Jasmonoyl-l-isoleucine is required for the production of a flavonoid phytoalexin but not diterpenoid phytoalexins in ultraviolet-irradiated rice leaves.

    Miyamoto, Koji; Enda, Isami; Okada, Toshiki; Sato, Yumiko; Watanabe, Kohei; Sakazawa, Tomoko; Yumoto, Emi; Shibata, Kyomi; Asahina, Masashi; Iino, Moritoshi; Yokota, Takao; Okada, Kazunori; Yamane, Hisakazu

    2016-10-01

    Rice produces low-molecular-weight antimicrobial compounds known as phytoalexins, in response to not only pathogen attack but also abiotic stresses including ultraviolet (UV) irradiation. Rice phytoalexins are composed of diterpenoids and a flavonoid. Recent studies have indicated that endogenous jasmonyl-l-isoleucine (JA-Ile) is not necessarily required for the production of diterpenoid phytoalexins in blast-infected or CuCl2-treated rice leaves. However, JA-Ile is required for the accumulation of the flavonoid phytoalexin, sakuranetin. Here, we investigated the roles of JA-Ile in UV-induced phytoalexin production. We showed that UV-irradiation induces the biosynthesis of JA-Ile and its precursor jasmonic acid. We also showed that rice jasmonate biosynthesis mutants produced diterpenoid phytoalexins but not sakuranetin in response to UV, indicating that JA-Ile is required for the production of sakuranetin but not diterpenoid phytoalexins in UV-irradiated rice leaves.

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

    Oelmüller, R; Kendrick, R E; Briggs, W R

    1989-08-01

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

  18. Comparison of H{sub 2} accumulation by Rhodobacter sphaeroides KD131 and its uptake hydrogenase and PHB synthase deficient mutant

    Kim, Mi-Sun; Baek, Jin-Sook [Biomass Research Center, Korea Institute of Energy Research, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Lee, Jeong K. [Department of Life Science, Sogang University, Shinsu-dong, Mapo-gu, Seoul 121-742 (Korea, Republic of)

    2006-01-15

    Rhodobacter sphaeroides KD131 and its mutant strain lacking uptake hydrogenase (Hup{sup -}) and PHB synthase (Phb{sup -}) have been studied on H{sub 2} production and cell growth under different culture conditions. Both strains started producing H{sub 2} from the middle of the logarithmic growth phase and continued until the cell concentration leveled out. The rates of H{sub 2} production were 1.32 and 3.34ml H{sub 2}/mg-dcw for the wild-type and Hup{sup -}/Phb{sup -} mutant strain, respectively, at the optimum conditions. Malate and lactate were better carbon sources than starch, sucrose or glycerol. Approximately 60% of acetic acid was degraded in 48h by the wild-type strain and pH increased to 9.4. However, the Hup{sup -}/Phb{sup -} mutant strain did not grow well and degraded only 19% of acetic acid. The pH ranges of 7.0 were the optimum for the cell growth and pH 7.5 for the H{sub 2} production. Both strains grew and produced hydrogen under the irradiance of 12-120W/m{sup 2}, but cell growth was inhibited over 400W/m{sup 2}. (author)

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

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

    2007-02-01

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

  20. OsCLT1, a CRT-like transporter 1, is required for glutathione homeostasis and arsenic tolerance in rice.

    Yang, Jian; Gao, Ming-Xing; Hu, Han; Ding, Xiao-Meng; Lin, Hong-Wei; Wang, Lei; Xu, Ji-Ming; Mao, Chuan-Zao; Zhao, Fang-Jie; Wu, Zhong-Chang

    2016-07-01

    Arsenic (As) contamination in a paddy environment can cause phytotoxicity and elevated As accumulation in rice (Oryza sativa). The mechanism of As detoxification in rice is still poorly understood. We isolated an arsenate (As(V))-sensitive mutant of rice. Genomic resequencing and complementation identified OsCLT1, encoding a CRT-like transporter, as the causal gene for the mutant phenotype. OsCLT1 is localized to the envelope membrane of plastids. The glutathione and γ-glutamylcysteine contents in roots of Osclt1 and RNA interference lines were decreased markedly compared with the wild-type (WT). The concentrations of phytochelatin PC2 in Osclt1 roots were only 32% and 12% of that in WT after As(V) and As(III) treatments, respectively. OsCLT1 mutation resulted in lower As accumulation in roots but higher As accumulation in shoots when exposed to As(V). Under As(III) treatment, Osclt1 accumulated a lower As concentration in roots but similar As concentration in shoots to WT. Further analysis showed that the reduction of As(V) to As(III) was decreased in Osclt1. Osclt1 was also hypersensitive to cadmium (Cd). These results indicate that OsCLT1 plays an important role in glutathione homeostasis, probably by mediating the export of γ-glutamylcysteine and glutathione from plastids to the cytoplasm, which in turn affects As and Cd detoxification in rice.

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

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

    2001-03-01

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

  2. 水稻雄性不育突变体012S-3的遗传分析和基因定位%Genetic Analysis and Gene Mapping of a Male Sterile Mutant 012S-3 in Rice

    欧阳杰; 王楚桃; 朱子超; 何永歆; 蒋刚; 黄乾龙; 管玉圣; 熊英; 李贤勇

    2015-01-01

    Male sterility is an important resource for utilization of Heterosis in rice. Research on male sterility has important theoretical significance and practical value. In this study, we investigated the phenotypic characteristics and pollen fertility of the rice natural male-sterile mutant 012S-3. The genetic populations were constructed for preliminary positioning of the target gene, and genome sequencing technology were used for fine positioning of the, target gene. The results showed that 012S-3 was a typical non-pollen type mutant of male sterility and its sterility was controlled by a pairs of recessive nuclear genes. Preliminary mapping analysis indicated the objective gene and SSR marker RM6081 linkage, and their genetic distance was about 34.4 cM. By further fine mapping analysis, three candidate genes were found: LOC_Os07g35880, LOC_Os07g35920 and LOC_Os07g35940. In which, LOC_Os07g35880 and LOC_Os07g35940 encoding two putative β-amylases, belong to the new pollen lethal genes in rice. The successful positioning of the sterile gene laid a foundation for its further isolation, cloning and its application in rice molecular design breeding.%雄性不育是水稻杂种优势利用的重要资源,对雄性不育现象的研究具有重要理论意义和实践价值。本研究以自然突变的水稻雄性不育突变体012S-3为试验材料,对其表型特征和花粉育性等进行调查,并构建遗传群体,利用分子标记对目的基因进行初步定位,然后应用基因组重测序技术对其进行精细定位。结果表明,012S-3是一个典型的无花粉普通型雄性不育材料,其不育性状受1对隐性核基因控制。初步定位分析目的基因与SSR标记RM6081存在连锁关系,其遗传距离约为34.4 cM;进一步的精细定位分析,找到3个候选基因:LOC_Os07g35880、LOC_Os07g35920和LOC_Os07g35940,其中LOC_Os07g35880和LOC_Os07g35940编码β-淀粉酶,属于水稻中新发现的花粉致死基因

  3. 水稻体细胞无性系雄性不育突变%Male Sterile Mutants from Rice Somaclones

    范树国; 梁承邺; 刘鸿先

    2000-01-01

    对5个类型的水稻不育系进行了幼穗培养,在红源A、包源A和W6154s中,共获得了10例雄性不育变异株,水稻花粉败育可分为无花粉、典败、圆败和染败四种类型。发现了不育花粉败育类型之间可以相互转换现象。对雄性不育变异株用一批现有CMS不育系的保持系和恢复系进行测交和回交,有的变异株其恢保关系发生了变化,由包台型变成了野败型;有的变异株找不到恢复系;而有的变异株则找不到保持系,表现为核不育的性质。%Young panicles from fiva rice varieties,Zhenshan 97A(WA type cytoplasmic malesterile(CMS)line,indica),Hongyuan A(HL type CMS line,indica),Baoyuan A(BT type CMS line,indica),Nongken 58s(photoperiod-sensitive genic male-sterile rice(PGMR),japonica)and W6154s(thermo-sensitive genic male-sterile rice(TGMR),indica),were cultured on the other was coded S14-1, TAT) and Baoyuan A (one was coded 28-5, SpAT; the other wascoded 28-19, TAT), kept sterile continuously for five generations when they were backcrossedwith the ten parents stated above.The other five male-sterile variants, which derived from Hongyuan A (coded 24-5),Baoyuan A(coded 28-35) and W6154s(coded WP-l, WP-2 and WS) turned into fertility with alot of fertile pollens and very high self seed set rate (more than 80%) when they were crossed with the ten parents stated above.different media. After obtained regenerating plants,examined pollen fertility,madetestcrosses of male-sterile variants,did genetic analyses of male-sterile variants,discussedrestoring and maintaining relationship of male sterile variants,we found 10 cases of male-sterilevariants in three rice variedes,Hongyuan A,Baoyuan A and W6154s.Abortive pollen of ricecould be classified into four types:pollen free type(PFT),typical abortion type (TAT),pherical abortion type(SpAT)and stained abortion type(StAT).The phenomenon that type of polln abortion

  4. The role of the rice aquaporin Lsi1 in arsenite efflux from roots.

    Zhao, Fang-Jie; Ago, Yukiko; Mitani, Namiki; Li, Ren-Ying; Su, Yu-Hong; Yamaji, Naoki; McGrath, Steve P; Ma, Jian Feng

    2010-04-01

    *When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. *Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. *Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 mum arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. *We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.

  5. Hd3a promotes lateral branching in rice.

    Tsuji, Hiroyuki; Tachibana, Chika; Tamaki, Shojiro; Taoka, Ken-Ichiro; Kyozuka, Junko; Shimamoto, Ko

    2015-04-01

    Accumulating evidence indicates that the FLOWERING LOCUS T (FT) protein is the mobile floral signal known as florigen. A rice FT homolog, Heading date 3a (Hd3a), is transported from the phloem to shoot apical cells, where it interacts with 14-3-3 proteins and transcription factor OsFD1 to form a florigen activation complex (FAC) that activates a rice homolog of the floral identity gene APETALA1. Recent studies showed that florigen has roles in plant development beyond flowering; however, the exact nature of these roles is not well understood. It is not clear whether FT is transported to organs outside the shoot apex, and whether FAC formation is required for processes other than flowering. We show here that the Hd3a protein accumulates in axillary meristems to promote branching, and that FAC formation is required. Analysis of transgenic plants revealed that Hd3a promotes branching through lateral bud outgrowth. Hd3a protein produced in the phloem reached the axillary meristem in the lateral bud, and its transport was required for promotion of branching. Moreover, mutant Hd3a proteins defective in FAC formation but competent with respect to transport did not promote branching. Finally, we show that Hd3a promotes branching independently from strigolactone and FC1, a transcription factor that inhibits branching in rice. Together, these results suggest that Hd3a functions as a mobile signal for branching in rice.

  6. Genetic Analysis and Gene Mapping of White Stripe Leaf Mutant st11 in Rice%水稻白条纹叶突变体 st11的遗传分析与基因定位

    成钦淑; 李仕贵; 陈学伟; 叶邦全#; 袁灿; 李伟滔; 尹俊杰; 王静; 贺闽; 汪吉春; 王玉平

    2015-01-01

    白条纹叶突变体 st11是从粳稻品种 Kitaake 组培过程中获得的。该突变体在分蘖前叶色表现为正常,从分蘖期开始新生叶表现为白条纹直至成熟期。与野生型相比,该突变体的分蘖、株高、结实率和千粒重等农艺性状没有发生明显变化。遗传分析表明该突变体白条纹叶性状受一对隐性核基因控制。利用该突变体分别与水稻02428、Jodan 杂交构建了两个F2群体用于基因定位。通过集群分离分析(bulked segregant analysis)发现该基因位于第1染色体端粒附近,并与分子标记RM151和 RM10080连锁。进一步利用更多分子标记分析 F2群体,我们将该基因定位于 I10和 I26两个标记之间大约270kb的区间内。%A white stripe leaf mutant st1 1 was obtained from tissue-cultured rice Kitaake (Oryza sativa spp j aponica ). This mutant was characterized by white stripe leaves from tillering stage to mature stage.Compared with the wild type Kitaake,the mutant showed no obvious changes in agricultural traits,such as tiller number,plant height,seed-setting rate,and grain weight.Genetic analyses showed that the white stripe leaf phenotype in the mutant st1 1 was controlled by a single recessive gene.Two F2 segregating populations derived from the crosses,st1 1 ×Jodan and st1 1 ×02428, respectively,were used for mapping the gene st1 1 .Bulked segregant analysis suggested that the gene st1 1 was located close to the markers,RM1 5 1 and RM10080,on chromosome 1 .Using more molecular markers,we finally delimited the gene st1 1 to a region of about 270 kb between the Indel markers,I10 and I26,on the telomere of the short arm of chromosome 1 .

  7. Characterization of a purine permease family gene OsPUP7 involved in growth and development control in rice.

    Qi, Zhuyun; Xiong, Lizhong

    2013-11-01

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

  8. Identification and Studies of a Rice Mutant hya-1 with Semi-dwarf and Aneuploid Traits%一份水稻半矮秆非整倍突变体hya-1的鉴定与研究

    郭涛; 刘永柱; 张建国; 陈志强; 王慧

    2012-01-01

    A semi-dwarfing rice mutant hya-1 , genetically unstable in plant height was obtained through space muta-genesis of Texianzhan 13. Compared to the wild type, hya-1 mutant was featured by semi-dwarfness, fewer tillers, slim culms, reduced grain number per panicle, low seed setting rate and low germination rate. Segregation of plant height in selfed progenies of the mutant was observed. Normal plants of selfed progenies, however, showed genetic stability. Plant height of F, hybrid and F2 progenies generated from the cross between hya-1 mutant and Texianzhan 13 did not follow Mendelian inheritance. Furthermore, selfed-progenies of the mutant had abnormal chromosome numbers (e.g. 2n = 22, 23, 25 and 36 instead of 2n- 24). In addition, there were some pollen mother cells of hya-1 with 11 bivalents at the diakinesis stage of meiosis. Real-time quantitative PCR analysis of normal and semi-dwarf plants from selfed progenies of the mutant along with Texianzhan 13 showed equal copy number of chromosome in normal and wild type plants while the copy number of chromosome 8 and 11 differed in hya-1 and semi-dwarf plants from the selfed progenies. It suggested that hya-1 mutant is a new aneuploid in which abnormal phenotype and genetic instability are caused by abnormal chromosome number and/or varying copy number of certain chromosomes.%通过空间诱变得到半矮秆突变体hya-1,该突变体半矮秆性状遗传稳定性丧失.与其野生型特籼占13相比,hya-1株高显著降低、分蘖少、茎秆细弱、每穗粒数减少、结实率降低、发芽率降低.单株收获半矮株hya-1自交种子,对半矮生性状进行连续选择,发现该性状无法纯合稳定,自交群体株高长期分离(半矮秆和野生型);分离群体中的野生型个体自交,其株高性状稳定.利用hya-1与特籼占13配制杂交组合,其F1及F2株高表型不符合孟德尔分离规律.hya-1自交收获种子根尖细胞染色体数目出现了 2n=22、23、24、25、36的变

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

    Carlos Eduardo Marchi

    2010-03-01

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

  10. Hydraulic conductance as well as nitrogen accumulation plays a role in the higher rate of leaf photosynthesis of the most productive variety of rice in Japan

    2011-01-01

    An indica variety Takanari is known as one of the most productive rice varieties in Japan and consistently produces 20–30% heavier dry matter during ripening than Japanese commercial varieties in the field. The higher rate of photosynthesis of individual leaves during ripening has been recognized in Takanari. By using pot-grown plants under conditions of minimal mutual shading, it was confirmed that the higher rate of leaf photosynthesis is responsible for the higher dry matter production aft...

  11. The Chloroplast Import Receptor Toc90 Partially Restores the Accumulation of Toc159 Client Proteins in the Arabidopsis thaliana ppi2 Mutant

    Sibylle Infanger; Sylvain Bischof; Andreas Hiltbrunner; Birgit Agne; Sacha Baginsky; Felix Kessler

    2011-01-01

    Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- (translocon at the outer chloroplast membrane) and Tic- (translocon at the inner chloroplast membrane) complexes. In Arabidopsis thaliana,precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families: Toc34/33 and Toc159/132/120/90. The role in import and precursor selectivity of these receptors has been intensively studied,but the function of Toc90 still remains unclear. Here,we report the ability of Toc90 to support the import of Toc159 client proteins. We show that the overexpression of Toc90 partially complements the albino knockout of Toc159 and restores photoautotrophic growth. Several lines of evidence including proteome profiling demonstrate the import and accumulation of proteins essential for chloroplast biogenesis and functionality.

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

    Xiaolin eWu

    2015-01-01

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

  13. An excretory function for the Escherichia coli outer membrane pore TolC: upregulation of marA and soxS transcription and Rob activity due to metabolites accumulated in tolC mutants.

    Rosner, Judah L; Martin, Robert G

    2009-08-01

    Efflux pumps function to rid bacteria of xenobiotics, including antibiotics, bile salts, and organic solvents. TolC, which forms an outer membrane channel, is an essential component of several efflux pumps in Escherichia coli. We asked whether TolC has a role during growth in the absence of xenobiotics. Because tolC transcription is activated by three paralogous activators, MarA, SoxS, and Rob, we examined the regulation of these activators in tolC mutants. Using transcriptional fusions, we detected significant upregulation of marRAB and soxS transcription and Rob protein activity in tolC mutants. Three mechanisms could be distinguished: (i) activation of marRAB transcription was independent of marRAB, soxR, and rob functions; (ii) activation of soxS transcription required SoxR, a sensor of oxidants; and (iii) Rob protein was activated posttranscriptionally. This mechanism is similar to the mechanisms of upregulation of marRAB, soxS, and Rob by treatment with certain phenolics, superoxides, and bile salts, respectively. The transcription of other marA/soxS/rob regulon promoters, including tolC itself, was also elevated in tolC mutants. We propose that TolC is involved in the efflux of certain cellular metabolites, not only xenobiotics. As these metabolites accumulate during growth, they trigger the upregulation of MarA, SoxS, and Rob, which in turn upregulate tolC and help rid the bacteria of these metabolites, thereby restoring homeostasis.

  14. Optimization of germanium accumulation conditions by yeast to ferment the organic rice bran%酵母菌发酵有机米糠富锗的条件优化

    白晓凯; 李艳娇; 金英海; 张敏; 陈石婷; 国传福

    2016-01-01

    试验以有机米糠为发酵底物,研究酵母菌对锗的生物富集作用,通过对富锗酵母生物量以及锗含量的测定,对此发酵试验的条件进行优化.试验结果显示:令初始pH值自然,米糠添加量32 g/250 ml、装液量80 ml/250 ml、接种量10%、时间60 h、温度30 ℃、GeO2 添加量为100 mg/l时,优化培养条件所得的富锗酵母菌发酵的有机米糠的有机锗生产水平为11.83 mg/kg.%The experiment took the organic rice bran as the fermentation substrate to study the biologi?cal accumulation function of the yeast to germanium. The biomass and germanium-enriched yeast were measured for optimizing the experiment conditions. The result showed: under the optimized condi?tions that the initial pH value was unchanged, the filling volume of organic rice bran was 32 g/250 ml, the filling volume of liquid medium was 80 ml/250 ml, the inoculum was 10%(v/v), the cultural time was 60 h, the cultural temperature was 30 ℃, GeO2 concentration was 100 mg/l, the organic germani?um production-level of the organic rice bran fermented by yeast was 11.83 mg/kg.

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

    Julia Kneissl; Tomoko Shinomura; Masaki Furuya; Cordelia Bolle

    2008-01-01

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

  16. 水稻类树状突变体s2-21的遗传分析与精细定位%Genetic Analysis and Gene Fine Mapping of Rice Leafy Head Mutant s2-21

    王海凤; 高洁; 孙伟; 张士永; 赵庆雷; 尹亮; 赵金凤; 李学勇; 袁守江

    2014-01-01

    叶序和出叶间隔期是叶片生长发育的基本生物学特性和水稻的重要农艺性状之一。对叶序或出叶间隔期突变体的研究,可以帮助我们了解叶片的形成机制。本研究通过甲基磺酸乙酯(EMS)诱变粳稻品种日本晴,获得一个稳定遗传的类树状突变体s2-21。该突变体出叶间隔期变短、节间缩短、植株矮化、分蘖数减少、叶片数增加、不能正常进行生殖生长。将该突变体与籼稻品种Dular杂交,遗传分析表明该突变体性状受1对隐性基因控制。通过InDel分子标记对s2-21/Dular F2群体进行遗传定位,将该基因初步定位在第1染色体InDel标记C1-15和S1-17之间。利用本实验已测序的籼稻品种Dular全基因组序列与NCBI (http://www.ncbi.nlm.nih.gov/)上提供的粳稻品种日本晴基因组序列比对,开发了6个新的InDel标记,最终将该基因定位在W25和W26之间约88 kb的区间内。测序结果表明该突变体中PLA2基因的第4个内含子的第5位碱基由G突变为A。%Phyllotaxy and plastochron are basic aspects of leaf development and the important agronomic traits of rice. The study of phyllotaxy or plastochron mutant will help us to understand the mechanism of leaf formation. In this study, a leafy head mutant s2-21 was isolated from an EMS (ethyl methane sulfonate) mutagenized japonica cultivar Nipponbare. It was characterized by shorter intervals between leaves, shortened internodes, dwarf plants, decreased tiller number, and increased leaf number. It was also unable to transit from vegetative to reproductive growth. Genetic analysis with a F2 population of the mutant and an indica cultivar Dular showed that this trait is controlled by a single recessive nucleus gene, which was primarily mapped between two insertion-deletion (InDel) markers C1-15 and S1-17 on chromosome 1. For the fine mapping, new InDel markers were designed by utilizing information of genomic sequences from

  17. 水稻穗颈极度缩短突变体sui(t)的遗传分析与基因定位%Genetic Analysis and Gene Mapping of Extremely Shortened Uppermost Internode Mutant sui(t) in Rice

    王晓雯; 苗润隆; 蒋钰东; 杜川; 杨正林; 凌英华; 何光华; 桑贤春

    2013-01-01

    One novel mutant,tentatively designated as sui(t),was discovered from the progeny of indica rice restorer line Jinhui10,whose seeds were treated with EMS (ethyl methane sulfonate).This mutant was characterized by fully sheathed panicle and was insensitive to GA3.Morphology analysis showed that its uppermost internode was greatly shortened while the other internodes were normal.Genetic analysis suggested that the mutational character was controlled by a single recessive gene.Zhonghua11 was crossed with sui(t) and the F2 population was then used for gene mapping.SUI(t) gene was mapped between the SSR markers RM5336/RM3425 and the tag end of the short arm of Chromosome Ⅰ.SSR and Indel markers were designed and S UI(t) gene was finally restricted within the region of RM3148 and ClIn002 (swu),with a genetic distance of 0.8 cM and 1.4 cM,respectively,and a physical distance of 382 kb.The above result provides a foundation for SUI(t) gene cloning and functional analysis.%来源于EMS处理籼型恢复系缙恢10号的穗颈节间极度缩短突变体其他节间与恢复系缙恢10号无显著变化,表现为全包穗,对GA3不敏感,暂命名为sui(t).遗传分析表明变异性状受一对隐性核基因控制.以中花11/sui(t)的F2隐性单株为定位群体,将sui(t)基因定位在第1染色体SSR标记RM5336,RM3425向短臂末端一侧,进一步合成SSR,Indel等标记,最终将sui(t)基因定位在RM3148和C1 In002(swu)之间,遗传距离分别为0.8 cM和1.4 cM,物理距离为382 kb,为下一步基因克隆和功能研究奠定了基础.

  18. Review on Mutation in Lateral Root of Rice

    ZHANG Xia; ZHANG Da; HAO Zaibin

    2011-01-01

    Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root reaction to various environmental factors as a contribution of root growth and rice yield, the relationship between root growth and stems/leaves/flowers/rice, genetic laws of root characters, etc. However, there are very few researches on lateral root mutant. This paper reviewed progresses of the lateral root mutant of rice from the perspectives of phytomorphology to plant physiology and biochemistry to the gene mapping, consisting of mechanism of developing lateral root of rice, gene cloning and functional analysis of lateral root development, the relationship between auxin and lateral roots, agronomic traits of lateral roots mutant, structure and morphology of root hairs, gravity anomaly of root, redox metabolism and proteomics researches of the mutation in lateral root of rice.

  19. Phytochromes Regulate SA and JA Signaling Pathways in Rice and Are Required for Developmentally Controlled Resistance to Magnaporthe grisea

    Xian-Zhi Xie; Yan-Jiu Xue; Jin-Jun Zhoua; Bin Zhang; Hong Chang; Makoto Takano

    2011-01-01

    Old leaves of wild-type rice plants (Oryza sativa L. Cv. Nipponbare)are more resistant to blast fungus (Mag-naporthe grisea)than new leaves. In contrast, both old and new leaves of the rice phytochrome triple mutant (phyAphyB-phyC)are susceptible to blast fungus. We demonstrate that pathogenesis-related class 1 (PR1)proteins are rapidly and strongly induced during M. Grisea infection and following exogenous jasmonate (JA)or salicylic acid (SA)exposure in the old leaves, but not in the new leaves of the wild-type. In contrast, the accumulation of PR1 proteins was significantly attenuated in old and new leaves of the phyAphyBphyC mutant. These results suggest that phytochromes are required for the induction of PR1 proteins in rice. Basal transcription levels of Prla and PRlb were substantially higher in the wild-type as compared to the phyAphyBphyC mutant, suggesting that phytochromes also are required for basal expression of PR1 genes. Moreover, the transcript levels of genes known to function in SA-or JA-dependent defense pathways were regulated by leaf age and functional phytochromes. Taken together, our findings demonstrate that phytochromes are required in rice for age-related resistance to M, grisea and may indirectly increase PR1 gene expression by regulating SA-and JA-dependent defense pathways.

  20. Screening and Expression of a Silicon Transporter Gene (Lsi1 in Wild-Type Indica Rice Cultivars

    Mahbod Sahebi

    2017-01-01

    Full Text Available Silicon (Si is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties.

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

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

    2014-04-01

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

  2. 水稻根际典型溶解性有机质对水稻幼苗累积无机汞的影响%Effects of Typical Dissolved Organic Matter in Rice Rhizosphere on the Accumulation of Inorganic Mercury by Rice Seedlings

    马岚; 吴永贵; 郑连鹏

    2014-01-01

    To investigate the effects of typical dissolved organic matter (DOM)on the bioavailability of inorganic mercury (IHg),IHg was complexed with representative DOM in rice rhisphere soil solutions, such as oxalic acid,citric acid and fulvic acid in order to study the effects of DOM on the uptake of IHg by rice plant,and IHg content in roots and leaves of rice seedlings was detected and the transfer coefficient of IHg in rice plant was analyzed.Results:Compared with the control composed of ultrapure water,the concentration of IHg in roots significantly decreased by 65.1% and 64.4% in oxalic acid and fulvic acid respectively.Oxalic acid and fulvic acid promoted IHg accumulation in leaves,while citric acid had no significant promotion effect;Transmission coefficients of IHg in oxalic acid and fulvic acid treatments were 0.34 and 0.31 respectively,significantly higher than the control(0.10).Conclusion:Oxalic acid and fulvic acid could not only inhibit the accumulation of IHg in rice roots,but also improve the transportation of IHg in rice plant,which may increase IHg content in leaves.%为研究水稻根际典型溶解性有机质(DOM)对无机汞生物可利用性的影响,选取草酸、柠檬酸、黄腐酸与无机汞络合,利用水稻幼苗进行无机汞的吸收累积试验,测定水稻幼苗根部及叶片中无机汞的含量,分析水稻植株内无机汞的转运系数。结果表明:草酸、黄腐酸处理组中水稻根部无机汞含量与对照(超纯水体系)相比分别降低65.1%、64.4%;草酸、黄腐酸促进叶片累积无机汞,柠檬酸则无明显作用;草酸、黄腐酸处理组中水稻无机汞的转运系数分别为0.34和0.31,明显高于对照(0.10)。结论:草酸、黄腐酸不仅抑制水稻根部无机汞的累积,还可提高无机汞在水稻植株体内的运输,进而增加水稻叶片中无机汞的含量。

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

    Changchun Chen

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

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

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

    2013-01-01

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

  5. Rice epigenomics and epigenetics: challenges and opportunities.

    Chen, Xiangsong; Zhou, Dao-Xiu

    2013-05-01

    During recent years rice genome-wide epigenomic information such as DNA methylation and histone modifications, which are important for genome activity has been accumulated. The function of a number of rice epigenetic regulators has been studied, many of which are found to be involved in a diverse range of developmental and stress-responsive pathways. Analysis of epigenetic variations among different rice varieties indicates that epigenetic modification may lead to inheritable phenotypic variation. Characterizing phenotypic consequences of rice epigenomic variations and the underlining chromatin mechanism and identifying epialleles related to important agronomic traits may provide novel strategies to enhance agronomically favorable traits and grain productivity in rice.

  6. Tapetum Degeneration Retardation is Critical for Aliphatic Metabolism and Gene Regulation during Rice Pollen Development

    Da-Sheng Zhang; Wan-Qi Liang; Zheng Yuan; Na Li; Jing Shi; Jue Wang; Yu-Min Liu; Wen-Juan Yu; Da-Bing Zhang

    2008-01-01

    As a complex wall system in flowering plants,the pollen outer wall mainly contains aliphatic sporopollenin;however,the mechanism for synthesizing these lipidic precursors during pollen development remains less well under-stood.Here,we report on the function of the rice tapetum-expressing TDR(Tapetum Degeneration Retardation)gene in aliphatic metabolism and its regulatory role during rice pollen development.The observations of transmission electron microscopy (TEM) and scanning electron microscopy(SEM)analyses suggested that pollen wall formation was significantly altered in the tdr mutant.The contents of aliphatic compositions of anther were greatly changed in the tdr mutant revealed by GC-MS(gas chromatography-mass spectrometry)testing,particularly less accumulated in fatty acids, primary alcohols,alkanes and alkenes,and an abnormal increase in secondary alcohols with carbon Iengths from C29 to C35 in tdr.Microarray data revealed that a group of genes putatively involved in lipid transport and metabolism were significantly altered in the tdr mutant,indicating the critical role of TDR in the formation of the pollen wall.Also,a wide range of genes tween wild-type and tdr.In addition to its function in promoting tapetum PCD,TDR possibly plays crucial regulatory roles in several basic biological processes during rice pollen development.

  7. Biallelic and Genome Wide Association Mapping of Germanium Tolerant Loci in Rice (Oryza sativa L..

    Partha Talukdar

    Full Text Available Rice plants accumulate high concentrations of silicon. Silicon has been shown to be involved in plant growth, high yield, and mitigating biotic and abiotic stresses. However, it has been demonstrated that inorganic arsenic is taken up by rice through silicon transporters under anaerobic conditions, thus the ability to efficiently take up silicon may be considered either a positive or a negative trait in rice. Germanium is an analogue of silicon that produces brown lesions in shoots and leaves, and germanium toxicity has been used to identify mutants in silicon and arsenic transport. In this study, two different genetic mapping methods were performed to determine the loci involved in germanium sensitivity in rice. Genetic mapping in the biparental cross of Bala × Azucena (an F6 population and a genome wide association (GWA study with 350 accessions from the Rice Diversity Panel 1 were conducted using 15 μM of germanic acid. This identified a number of germanium sensitive loci: some co-localised with previously identified quantitative trait loci (QTL for tissue silicon or arsenic concentration, none co-localised with Lsi1 or Lsi6, while one single nucleotide polymorphism (SNP was detected within 200 kb of Lsi2 (these are genes known to transport silicon, whose identity was discovered using germanium toxicity. However, examining candidate genes that are within the genomic region of the loci detected above reveals genes homologous to both Lsi1 and Lsi2, as well as a number of other candidate genes, which are discussed.

  8. Endoplasmic reticulum membrane-bound MoSec62 is involved in the suppression of rice immunity and is essential for the pathogenicity of Magnaporthe oryzae.

    Zhou, Zhuangzhi; Pang, Zhiqian; Li, Guihua; Lin, Chunhua; Wang, Jing; Lv, Qiming; He, Chaozu; Zhu, Lihuang

    2016-10-01

    Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) constitutes the first line of plant inducible immunity. As an important step of plant colonization, phytopathogens have to suppress PTI, and secreted effectors are therefore co-evolved and deployed. In this study, we characterized the function of MoSec62 of Magnaporthe oryzae, the causal agent of the destructive rice blast. MoSec62 encodes a homologue of Sec62p, a yeast endoplasmic reticulum (ER) membrane transporter for precursors of secretory proteins. We showed that a T-DNA insertion into the promoter region of MoSec62, causing a disturbance to the up-regulation of MoSec62 expression during blast invasion, resulted in a complete loss of blast virulence of the mutant, M1575. Both 3,3'-diaminobenzidine (DAB) staining of the infected rice leaves and expression analysis revealed that the infectious attempt by the mutant led to strong defence responses of rice. Consistently, in transcriptomic analysis of rice leaves subject to blast inoculation, a battery of defence responses was found to be induced exclusively on M1575 challenge. For further exploration, we tested the pathogenicity on a highly susceptible rice variety and detected the accumulation of Slp1, a known PTI suppressor. Both results suggested that the mutant most likely failed to overcome rice PTI. In addition, we showed that MoSec62 was able to rescue the thermosensitivity of a yeast Δsec62, and the MoSec62-GFP fusion was co-localized to the ER membrane, both suggesting the conservation of Sec62 homologues. In conclusion, our data indicate that MoSec62, probably as an ER membrane transporter, plays an essential role in antagonizing rice defence at the early stages of blast invasion.

  9. The role of nodes in arsenic storage and distribution in rice.

    Chen, Yi; Moore, Katie L; Miller, Anthony J; McGrath, Steve P; Ma, Jian Feng; Zhao, Fang-Jie

    2015-07-01

    Knowledge of arsenic (As) accumulation in rice (Oryza sativa L.) is important for minimizing As transfer to the food chain. The aim of this study was to investigate the role of rice nodes in As storage and distribution. Synchrotron μX-ray fluorescence (μ-XRF) was used to map As distribution in the top node and internode of a lsi2 mutant defective in silicon/arsenite efflux carrier and its wild-type (WT) grown in soil. Lsi2 expression in different tissues during grain filling was investigated by quantitative RT-PCR. Arsenite or dimethylarsinic acid (DMA) was supplied to excised panicles to investigate the roles of Lsi2 and phytochelatins (PC) in As distribution. μ-XRF mapping revealed As storage in the phloem of different vascular bundles in the top node and internode. Soil-grown plants of lsi2 had markedly decreased As accumulation in the phloem compared with the WT. Lsi2 was strongly expressed, not only in the roots but also in the nodes. When excised panicles were exposed to As(III), the lsi2 mutant distributed more As to the node and flag leaf but less As to the grain compared with the WT, while there was no significant difference in DMA distribution. Inhibition of PC synthesis by l-buthionine-sulphoximine decreased As(III) deposition in the top node but increased As accumulation in the grain and flag leaf. The results suggest that rice nodes serve as a filter restricting As(III) distribution to the grain. Furthermore, Lsi2 plays a role in As(III) distribution in rice nodes and phytochelatins are important compounds for As(III) storage in the nodes.

  10. Gibberellin Signal Transduction in Rice

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

    2007-01-01

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

  11. Genetic resources offer efficient tools for rice functional genomics research.

    Lo, Shuen-Fang; Fan, Ming-Jen; Hsing, Yue-Ie; Chen, Liang-Jwu; Chen, Shu; Wen, Ien-Chie; Liu, Yi-Lun; Chen, Ku-Ting; Jiang, Mirng-Jier; Lin, Ming-Kuang; Rao, Meng-Yen; Yu, Lin-Chih; Ho, Tuan-Hua David; Yu, Su-May

    2016-05-01

    Rice is an important crop and major model plant for monocot functional genomics studies. With the establishment of various genetic resources for rice genomics, the next challenge is to systematically assign functions to predicted genes in the rice genome. Compared with the robustness of genome sequencing and bioinformatics techniques, progress in understanding the function of rice genes has lagged, hampering the utilization of rice genes for cereal crop improvement. The use of transfer DNA (T-DNA) insertional mutagenesis offers the advantage of uniform distribution throughout the rice genome, but preferentially in gene-rich regions, resulting in direct gene knockout or activation of genes within 20-30 kb up- and downstream of the T-DNA insertion site and high gene tagging efficiency. Here, we summarize the recent progress in functional genomics using the T-DNA-tagged rice mutant population. We also discuss important features of T-DNA activation- and knockout-tagging and promoter-trapping of the rice genome in relation to mutant and candidate gene characterizations and how to more efficiently utilize rice mutant populations and datasets for high-throughput functional genomics and phenomics studies by forward and reverse genetics approaches. These studies may facilitate the translation of rice functional genomics research to improvements of rice and other cereal crops.

  12. Effects of Different Nitrogen Application on Dry Matter Accumulation and Nitrogen Utilization Efficiency of Rice%氮肥运筹对水稻干物质积累和氮肥利用率的影响

    李殿平

    2014-01-01

    Tiejing No.7 was used to research the effects of different nitrogen application on dry matter accumulation and nitrogen utilization efficiency of rice.The results showed that the increase of nitrogen fertilizer application contributed the increase of the dry matter accumulation of the variety Tiejing No.7,reaching 15 570 kg/hm2,on the condition of that application amount of pure nitrogen was 255 kg/hm2 and the ratio of basal fertilizer and tillering fertilizer was 8:2.Meanwhile,the increase of nitrogen fertilizer application also enhanced total nitrogen absorption amount,but lowered nitrogen recovery rate and nitrogen harvest index declined.However,nitrogen physiological utilization ratio was highest with the treatment of pure nitrogen 210 kg/hm2.%以北方超级稻铁粳7号为试材,重点分析了氮肥运筹对水稻生产干物质积累和氮肥利用率的影响。结果表明,增加施氮量有利于提高铁粳7号的干物质重,在施纯氮255 kg/hm2、基蘖肥与穗粒肥比为8:2处理下成熟期的总干物重达到最高为15570 kg/hm2;增加施氮量会提高铁粳7号的总吸氮量,但氮素回收率和氮素收获指数会下降,而氮素生理利用率以施纯氮210 kg/hm2处理最高。

  13. Accumulation of Mutant Genes and Its Pathway with Reproductive Isolation%突变基因的积累与生殖隔离形成的一个途径

    韦文惠

    2010-01-01

    通过用RR、Rr和rr 3种基因型的适合度之比量化R与r基因在后代中的频率,计算r的频率逐代演变的分岔点,研究随机交配群体中的杂合子适合度低于纯合子适合度的突变基因r在群体中的逐代积累过程.揭示了R与r在遗传中的不相容性;遗传漂变能使r在新群体中有较高的频率,超过分岔点,最终形成生殖隔离;同时生物进化的动力仅有突变、遗传漂变、自然选择这3个条件还不够,还需要有杂合子适合度低于纯合子适合度的突变基因,即原有群体的遗传背景对新突变的排斥作用.%According to the fitness of heterozygote was lower than homozygote among panmictic population,the process of generational accumulate of mutant gene r was considered.Branch point of r's frequency by generational evolution which revealed the hereditary incompatibility between R and r,was worked out,and it was found that genetic drift can make r have higher frequency to surpass the branch point to form reproductive isolation.It was not enough to have the three conditions of mutation,genetic drift and natural selection to be the drive of biological evolution; hybrid weakness,the repelling interaction between the genetic background of original population and the new mutation,were also needed.

  14. Modeling Plant Nitrogen Uptake and Grain Protein Accumulation in Rice%水稻植株氮素吸收与籽粒蛋白质积累模型

    陈洁; 汤亮; 刘小军; 曹卫星; 朱艳

    2011-01-01

    [目的]建立基于生理生态过程的水稻籽粒蛋白质积累模拟模型.[方法]基于不同地点、品种及施氮水平的田间试验资料,通过解析花前植株氮素吸收与积累,花后氮素吸收与转运的动态特征及定量关系,构建水稻植株氮素吸收与籽粒蛋白质积累的模拟模型.[结果]水稻籽粒中氨素积累速率取决于源限制下的可获取氮源和库限制下的氮素积累速率;源限制下的可获取氮源取决于营养器官向籽粒转运的氮素和花后植株吸收的氮素,库限制下的氮素积累速率由潜在氮素积累速率及温度、水分和氮素因子效应来综合决定.营养器官中的氮素转运又分为叶片和茎中积累氮素的转运;花前叶片和茎中的相对氮含量随播后生长度日线性增加;花后叶片和茎中的相对氮含量随花后生长度日线性递减;花后吸收的氮素随籽粒重的增加对数递增.利用独立的田问试验资料对所建模型进行了检验,结果显示模拟值与观测值之间具有较好的一致性,其中花前叶片与茎秆氮素吸收量、花后籽粒氮素吸收量、花后叶片与茎秆中氮素转运量的决定系数分别为0.968、0.980、0.974、0.970和0.976,根均方差分别为16.55%,13.24%,9.53%、10.93%和9.29%;籽粒蛋白质含量的决定系数分别为0.930,根均方差分别为7.82%.[结论]模型对不同栽培条件下水稻植株氮素吸收与转运以及籽粒蛋白质积累具有较好的预测性,为水稻生产中籽粒蛋白质指标的动态预测提供了量化工具.%[Objective] Grain protein content is an important quality index in rice. The objective of this study was to develop a process based simulation model for predicting the content and accumulation of grain protein under different cultural conditions.[Method] On the basis of the field experiments involving different eco-sites, cultivar types and nitrogen rates, the fundamental relationships between grain protein

  15. Analysis of disease resistance and its mechanism in rice lesion mimic mutant spl5%水稻类病变突变体spl5的抗病及其机理分析

    傅淑芳; 陈析丰; 郝亮; 孙青芝; 金杨; 马伯军

    2013-01-01

    超敏反应(hypersensitive response,HR)是植物抵御病原物的一种有效方式.植物类病变(lesion mimic)是一类能自发产生类似HR细胞坏死的突变体,在植物抗病机理研究中具有重要意义.对水稻类病变突变体spl5的抗病性研究发现,spl5增强了对白叶枯病菌4个菲律宾小种和10个中国小种的抗性,具有广谱抗病性.在spl5中活性氧显著积累,表现出HR的早期特征“氧迸发”现象,活性氧清除酶SOD,POD和CAT的酶活力也显著性变化,表明spl5中活性氧代谢的平衡失调可能是诱发HR原因之一.同时,RT-PCR分析发现1个水杨酸(EDS1)和2个茉莉酸(AOS2,LOX2)信号途径中的关键调控基因及其下游2个病程相关基因(PR1a,PR1b)在spl5中表达上调,推测spl5的突变可能激活了水杨酸与茉莉酸途径的信号转导,从而启动了植株的系统防御应答反应.%Hypersensitive response ( HR) is an effective way of plants against pathogens. Lesion mimic mutants spontaneously exhibit HR-like cell death in absence of pathogens, and are of great significance in dissecting the molecular mechanisms of disease resistance in plants. In this study, it was found that the resistance against 4 Philippine races and 10 Chinese races was significantly enhanced in the spl5 mutant, indicating that the spl5 mutant displays a broad-spectrum resistance to Xoo. Reactive oxygen species (ROS) were significantly accumulated in spl5 leaves, which is an early feature of HR with reactive oxygen burst, meanwhile, activities of ROS scavenging enzymes such as SOD, POD and CAT significantly changed in sp!5, indicating that the imbalance of ROS metabolism might trigger HR occurrence in spl5. In addition, RT-PCR-based assay showed that transcriptional levels of EDS1, AOS2 and LOX2, key regulators in salicylic acid (SA) and jasmonic acid ( JA) signaling pathways, respectively, and their downstream pathogenesis-related genes such as PRla and PRlb were up-regulated in splS. Taken

  16. Effect of Control Irrigation on Soil Temperature and Dry Matter Accumulation of Rice During Tillering Stage%分蘖期控制灌溉对土温及水稻干物质积累等的影响

    雷舜; 王抄抄; 黄炎; 黄穗华; 符如壮; 唐湘如

    2016-01-01

    To investigate the optimum mode of irrigation in double-harvest rice area in South China during tille-ring stage,super rice Yuxiangyouzhan was selected as experimental material;field experiment was conducted in SCAU farm in 2014.Two water gradient treatments were set respectively in two different tillering stages,soil temper-atures were recorded during treatment periods,effect of control irrigation on dry matter accumulation,dynamic of LAI change,photosynthetic characteristics,panicle rate and yield were studied.Results showed that:control irriga-tion during tillering stage(the average relative soil water content reach about (60 ±5 )% at 0 -20 cm soil layer) could enlarge soil diurnal temperature range in 5 cm soil layer,reduce dry matter accumulation before jointing stage,improve photosynthetic rate and LAI in late growth stage,matter accumulation dynamic was optimized thus W1 & W2′s panicle rate and yield were improved.Therefore,control 0 -20 cm soil layer′s average relative water content at (60 ±5)% during tillering stage of Yuxiangyouzhan could attain the goal of water-saving and high-effi-ciency cultivation.%为了研究超级稻在双季稻区分蘖时期的最佳控水模式,2014年在华南农业大学农场以超级稻玉香油占为试材进行大田试验。在水稻分蘖数达到不同的2个阶段分别设置2个水分梯度处理,记录了控制灌溉期间土壤温度的变化,研究了其对干物质积累动态、LAI 变化动态、光合特性以及成穗率和最终产量等的影响。结果表明:分蘖期控制灌溉(0~20 cm 土层平均土壤相对含水率为(60±5)%能够扩大土壤5 cm 深度日温差,减少拔节前干物质积累,提高拔节期净光合速率和生育后期叶面积指数,优化干物质积累动态,最终提高了 W1和 W2处理的成穗率与产量。因此,在玉香油占分蘖期控制0~20 cm 土层平均土壤相对含水率为(60±5)%,能够达到节水高效栽培的目的。

  17. 水稻矮杆多分蘖突变体CA648的光合生理特性分析%Photosynthetic Physiological Analysis on Dwarf Multi-Tillering Rice Mutant CA648

    刘晓鹏; 朱允华; 刘清; 史齐; 李合松

    2015-01-01

    The chlorophyll content, photosynthetic rate, sugar and sucrose contents, POD enzyme activity of rice mutant (CA648, performing a dwarf and multi-tillering phenotype) and wild type ZH11 were preliminary studied. The results showed that the chlorophyll content of ZH11 was higher than that of CA648 at tillering stage. At the early stage of tillering, the net photosynthetic rate, stomatal conductance, and transpiration rate of CA648 were lower than those of ZH11, but intercellular CO2 concentration in CA648 was higher than that in ZH11. At the top tillering stage (20 d after tillering stage), the significant difference of the net photosynthetic rates of two kinds of material was found. The net photosynthetic rate of ZH11 was about 17.5% higher than CA648. Meanwhile, stomatal conductance, transpiration rate and intercellular CO2 concentration of ZH11 were also higher than those of CA648. At the late tillering stage, the net photosynthetic rates of ZH11 and CA648 were almost the same. At the top tillering stage, reducing sugar content in CA648 leaf was significantly higher than the control, while there was no difference of reducing sugar content in the two kinds of stems. The sucrose content of leaf in CA648 was lower than the control, about 77.5% of ZH11, while the sucrose content in the stem was 30.7% higher than ZH11. There were obvious differences of POD enzyme activity between two kinds of material. At the mid-tillering stage, the POD activities in leaf and stem of CA648 were 73.0% and 16.8% higher than those in ZH11, respectively.%本研究分析了水稻矮杆多分蘖突变体丛矮648(CA648)及对照中花11(ZH11)在分蘖期叶片的叶绿素含量、光合速率,还原糖、蔗糖含量以及POD酶活力。结果表明,分蘖期ZH11剑叶中叶绿素含量高于CA648。水稻分蘖前期,CA648的净光合速率、气孔导度、蒸腾速率都低于ZH11,胞间CO 2浓度高于ZH11;而在分蘖盛期(分蘖期后20 d)两种材料的净

  18. 水稻多分蘖矮秆突变体d63的遗传分析与基因定位%Genetic Analysis and Gene Mapping of a New Multi-tiller and Dwarf Mutant d63 in Rice

    薛晶晶; 吴绍华; 张红宇; 徐培洲; 吴先军

    2012-01-01

    The Multi-tiller and dwarf mutant d63 was a spontaneous mutation of the twin-seedling progenies, which were derived from the cross between diploid SAR fl[ and Minghui 63. Compared with the wild type, the d63 mutant showed multiple abnormal phenotypes, such as dwarfism, more tillers, smaller flag leaf, reduced seed-setting rate and 1000-grain weight. Genetic analysis indicated that the mutant was controlled by a single recessive gene on chromosome 8. The gene was finally located on the short arm of chromosome 8, 0. 4 cM from RM22195, where 14 ORFs were predicted based on Rice Genome Annotation. Do3 might be a new gene as there was no dwarf genes reported on the short arm of chromosome 8.%多分蘖矮秆突变体d63来源于SARⅢ二倍体与明恢63杂交得到的双胚苗株系的自然突变.与野生型相比,其株高显著下降,分蘖明显增多,剑叶变细变短,结实率和千粒重均大幅下降.遗传分析表明,该突变性状受一对隐性单基因控制.该基因位于水稻第8染色体短臂上距离RM22195约0.4 cM的位置.用水稻基因组注释软件Rice Genome Annotation预测,发现从端粒区至RM22195间共有14个注释基因,未发现已经报道的与株高、分蘖相关的同源基因.因此,推测D63可能是一个未被报道的新基因.

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

    Fei Wang

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

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

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

    2016-01-01

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

  1. ELONGATED UPPERMOST INTERNODE encodes a cytochrome P450 monooxygenase that epoxidizes gibberellins in a novel deactivation reaction in rice.

    Zhu, Yongyou; Nomura, Takahito; Xu, Yonghan; Zhang, Yingying; Peng, Yu; Mao, Bizeng; Hanada, Atsushi; Zhou, Haicheng; Wang, Renxiao; Li, Peijin; Zhu, Xudong; Mander, Lewis N; Kamiya, Yuji; Yamaguchi, Shinjiro; He, Zuhua

    2006-02-01

    The recessive tall rice (Oryza sativa) mutant elongated uppermost internode (eui) is morphologically normal until its final internode elongates drastically at the heading stage. The stage-specific developmental effect of the eui mutation has been used in the breeding of hybrid rice to improve the performance of heading in male sterile cultivars. We found that the eui mutant accumulated exceptionally large amounts of biologically active gibberellins (GAs) in the uppermost internode. Map-based cloning revealed that the Eui gene encodes a previously uncharacterized cytochrome P450 monooxygenase, CYP714D1. Using heterologous expression in yeast, we found that EUI catalyzed 16alpha,17-epoxidation of non-13-hydroxylated GAs. Consistent with the tall and dwarfed phenotypes of the eui mutant and Eui-overexpressing transgenic plants, respectively, 16alpha,17-epoxidation reduced the biological activity of GA(4) in rice, demonstrating that EUI functions as a GA-deactivating enzyme. Expression of Eui appeared tightly regulated during plant development, in agreement with the stage-specific eui phenotypes. These results indicate the existence of an unrecognized pathway for GA deactivation by EUI during the growth of wild-type internodes. The identification of Eui as a GA catabolism gene provides additional evidence that the GA metabolism pathway is a useful target for increasing the agronomic value of crops.

  2. Ethylene responses in rice roots and coleoptiles are differentially regulated by a carotenoid isomerase-mediated abscisic acid pathway.

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-04-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice.

  3. 基于CRISPR/Cas9技术的水稻千粒重基因tgw6突变体的创建%Construction of tgw6 Mutants in Rice Based on CRISPR/Cas9 Technology

    王加峰; 郑才敏; 刘维; 罗文龙; 王慧; 陈志强; 郭涛

    2016-01-01

    A set oftgw6 (Thousand-grain weight 6) mutants were constructed using CRISPR/Cas9 technology in this study. Three sites of 20 nt guide RNA (gRNA) targeted to the exon ofTGW6were designed and transcribed from the U3, U6a, or U6b promo-ters, respectively. The three target sites of gRNA were then ligated to the vector pYLCRISPR/Cas9-MT(I) based on golden gate cloning strategy. The recombinant plasmid was transferred to a rice cultivar, H447 (R819/Yuzhenxiang//R819 BC3F6) byAgro-bacterium-mediated transformation. Sequencing for the genomic DNA ofTGW6locusinT0 rice showed the mutagenesis fre-quency forTGW6was more than 90%, including 51% of homozygous deletion mutations. Further analysis for the T1 mutants showed that almost all the homozygous deletion mutants improved the thousand-grain weight significantly (more than 5%). The successfultgw6 editing not only provided a series oftgw6mutants for high and stable yield of rice but also proved that CRISPR/Cas9 is a facile and powerful means of rice genetic engineering for scientific and agricultural applications, which has important theoretical and practical significance for rice breeding.%利用CRISPR/Cas9技术对调控水稻产量千粒重基因TGW6定点编辑,获得了一套有重要育种价值的tgw6突变体。设计了分别由U3、U6a和U6b启动子驱动、长20 bp的guide RNA (gRNA)靶点以靶向编辑TGW6基因的外显子,首先将这3个靶点一起组装到 pYLCRISPR/Cas9-MT(I)载体上,然后利用农杆菌介导侵染水稻材料 H447(R819/玉针香//R819的BC3F6);提取T0代转基因植株的基因组DNA并对编辑位点附近的DNA片段进行PCR检测及测序分析。结果表明, T0代材料中tgw6的突变频率高达90%,其中纯合缺失突变率约占51%。对T1代纯合缺失突变体的千粒重性状的调查分析结果表明,部分tgw6的缺失突变能显著提高千粒重(大于5%)。不同类型tgw6突变体的成功创建不仅丰富了tgw6的变异类型,为水稻的

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

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

    2016-08-01

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

  5. The Puzzle of Rice Domestication

    Tao Sang; Song Ge

    2007-01-01

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

  6. Effects of aleurone layer on rice cooking: A histological investigation.

    Wu, Jianyong; Chen, Jun; Liu, Wei; Liu, Chengmei; Zhong, Yejun; Luo, Dawen; Li, Zhongqiang; Guo, Xiaojuan

    2016-01-15

    Understanding how aleurone layer (AL) affects rice cooking behaviour is important for rice processing. Individual effects of AL on rice cooking behaviour were evaluated and histological characters of AL before and after cooking were investigated. AL slightly affected rice cooking quality (optimum cooking time, water absorption, volume expansion ratio and total solids loss) while remarkably affected rice texture (hardness and adhesiveness) and peak viscosity. Histological investigation showed that channels were formed in AL during cooking. The channels facilitated the penetration of water, which could explain why AL exhibited slight effects on rice cooking quality. In addition, thick cell walls and thermally stable aleurone grains were widely distributed in AL. Leached components accumulated on them and formed a reinforced coated film on rice surface during cooking, which may be a possible mechanism accounting for the remarkable effect of AL on rice texture. Histological characters of AL are closely related with rice cooking behaviour.

  7. Effects of the Mutant with Low Chlorophyll Content on Photosynthesis and Yield in Rice%水稻低叶绿素含量突变对光合作用及产量的影响

    顾骏飞; 周振翔; 李志康; 戴琪星; 孔祥胜; 王志琴; 杨建昌

    2016-01-01

    A chlorophyll-deficit rice mutant (YL) with ~51% chlorophyll of its wild type (WT) was 3.7%, 20.4%, and 39.1%higher in photosynthesis than WT under saturating light condition, in treatments of 0 kg N ha–1, 120 kg N ha–1, 240 kg N ha–1, respectively. In the field and pot experiments, we studied leaf Rubisco content, stomatal conductance, expression levels of aq-uaporin genes, chlorophyll fluorescence, light and electron micrographs at different levels of N application. The results showed that the decreased level of chlorophyll content in YL was compensated by a relatively higher quantum yield of PSII. The electron micrographs of chloroplasts showed that there were no differences in chloroplast development between YL and WT. The stomatal conductance was much higher in the mutant than in wild type, and expression levels of the aquaporin genes suggested a higher mesophyll conductance in YL. The higher CO2 conductance together with a higher Rubisco content in YL could be reasons for the higher photosynthetic rate. The yield of YL was similar to that of WT, but the growth duration in YL was much shorter, which could be caused by the different photosynthetic performance between YL and WT. All these results implicate that higher photo-synthetic rate does not necessitate higher chlorophyll content. Moderate chlorophyll content will benefit the leaf photosynthesis. Decreasing N investment in chlorophyll synthesis and optimizing N distribution among different photosynthetic compounds could potentially improve photosynthesis and yield. The YL material used in this study could be potentially used to improve photosyn-thetic efficiency in breeding programmes.%突变体水稻叶绿素含量仅是其野生型水稻的51%,但是其饱和光合值在低氮、中氮、高氮处理下,却比对照野生型水稻分别高3.7%、20.4%与39.1%。为了探究其生理学机制,分别在大田与盆栽试验中,不同氮肥水平下研究了突变体材

  8. Arsenic Transport in Rice and Biological Solutions to Reduce Arsenic Risk from Rice

    Chen, Yanshan; Han, Yong-He; Cao, Yue; Zhu, Yong-Guan; Rathinasabapathi, Bala; Ma, Lena Q.

    2017-01-01

    Rice (Oryza sativa L.) feeds ∼3 billion people. Due to the wide occurrence of arsenic (As) pollution in paddy soils and its efficient plant uptake, As in rice grains presents health risks. Genetic manipulation may offer an effective approach to reduce As accumulation in rice grains. The genetics of As uptake and metabolism have been elucidated and target genes have been identified for genetic engineering to reduce As accumulation in grains. Key processes controlling As in grains include As uptake, arsenite (AsIII) efflux, arsenate (AsV) reduction and AsIII sequestration, and As methylation and volatilization. Recent advances, including characterization of AsV uptake transporter OsPT8, AsV reductase OsHAC1;1 and OsHAC1;2, rice glutaredoxins, and rice ABC transporter OsABCC1, make many possibilities to develop low-arsenic rice. PMID:28298917

  9. Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields

    Jiang, Yu; Huang, Xiaomin; Zhang, Xin; Zhang, Xingyue; Zhang, Yi; Zheng, Chengyan; Deng, Aixing; Zhang, Jun; Wu, Lianhai; Hu, Shuijin; Zhang, Weijian

    2016-07-01

    Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions.

  10. The rice OsLpa1 gene encodse a novel protein involved in phytic acid metabolism

    The rice low phytic acid 1 (OsLpa1) gene was originally identified using a forward genetics approach. Mutation of this gene resulted in a 45% reduction in rice seed phytic acid with a molar-equivalent increase in inorganic phosphorus; however, the rice lpa1 mutant does not appear to differ significa...

  11. 水稻籽粒发育过程中各器官镉积累量的变化及其与基因型和土壤镉水平的关系%Changes in Cadmium Accumulation in Rice Organs during Grain Develop-ment and Their Relationship with Genotype and Cadmium Levels in Soil

    居学海; 张长波; 宋正国; 韩立娜; 陆仲烟; 王景安; 刘仲齐

    2014-01-01

    Two indica rice (Oryza sativa) genotypes with different Cd accumulation potential were used to study the dynamic changes of Cd concentration in organs during grain developmental stage and their relation-ship with Cd levels in soil. Experimental results showed that rice root maintained a steady increase trend in Cd concentration during the rice life cycle. Other organs, i.e. stem, leaves, rachis and hull, accumulated a lot of Cd during vegetative growth stage and exported some of Cd during grain iflling period. More than 50%of Cd in lfag leaf and hull was exported out at reproductive stage. Low-Cd-accumulation (LCA) variety‘X24’ displayed apparently lower Cd content in rachis than high-Cd-accumulation (HCA) variety‘T705’. It indicated that Cd transport rate from vegetative organs to grains was the key factor limiting Cd accumulation in rice grains. How-ever, Cd content in polished rice of LCA variety was only signiifcantly lower than that of HCA variety when rice was planted in the soil containing Cd 0.3-1.2 mg·kg-1. When contaminated Cd in soil was above 2.4 mg·kg-1, the Cd accumulation in polished rice of LCA variety was similar to that of HCA variety.%以镉(Cd)积累潜力不同的2个籼稻品种为材料,研究了籽粒发育过程中各器官中Cd含量的动态变化及其与土壤中Cd含量的关系。结果表明,在含Cd的生长环境中,水稻根系中的Cd含量在整个生育期中保持稳定增长的趋势,而茎叶、穗轴和稻壳等器官在营养生长阶段积累了大量的Cd,然后在籽粒充实过程中向外输出,其中旗叶和稻壳中的Cd输出率在50%以上,明显高于其他营养器官。根系和叶片中的Cd含量与土壤中的Cd含量呈高度线性相关,茎秆和籽粒中的Cd含量与土壤中的Cd含量呈抛物线相关,说明根系、茎秆、叶片等营养器官对Cd有储存和“过滤”作用。低积累品种‘X24’穗轴中的Cd含量明显低于高积累品种‘T705’,说明营养器官中的Cd

  12. Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

    2007-01-01

    The interplanting with zero-tillage of rice, i.e. directsowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting), ZI (Zero-tillage, no straw manure and rice interplanting), PTS (Plowing tillage, straw manure and rice transplanting), and PT (Plowing tillage, no straw manure and rice transplanting), were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002), there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003). Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in

  13. Connexin mutants and cataracts

    Eric C Beyer

    2013-04-01

    Full Text Available The lens is a multicellular, but avascular tissue that must stay transparent to allow normal transmission of light and focusing of it on the retina. Damage to lens cells and/or proteins can cause cataracts, opacities that disrupt these processes. The normal survival of the lens is facilitated by an extensive network of gap junctions formed predominantly of connexin46 and connexin50. Mutations of the genes that encode these connexins (GJA3 and GJA8 have been identified and linked to inheritance of cataracts in human families and mouse lines. In vitro expression studies of several of these mutants have shown that they exhibit abnormalities that may lead to disease. Many of the mutants reduce or modify intercellular communication due to channel alterations (including loss of function or altered gating or due to impaired cellular trafficking which reduces the number of gap junction channels within the plasma membrane. However, the abnormalities detected in studies of other mutants suggest that they cause cataracts through other mechanisms including gain of hemichannel function (leading to cell injury and death and formation of cytoplasmic accumulations (that may act as light scattering particles. These observations and the anticipated results of ongoing studies should elucidate the mechanisms of cataract development due to mutations of lens connexins and abnormalities of other lens proteins. They may also contribute to our understanding of the mechanisms of disease due to connexin mutations in other tissues.

  14. A Dynamic Model of Dry Matter and Nutrient Accumulation in Super Hybrid Rice and Analysis of Its Characteristics%超级杂交稻群体干物质和养分积累动态模型与特征分析

    纪洪亭; 冯跃华; 何腾兵; 潘剑; 范乐乐; 李云; 武彪; 肖铭; 梁显林

    2012-01-01

    [Objective] Modeling dynamics of dry matter and nutrient accumulation of super hybrid rice is an important task for further improvement of yield and rational application of fertilizer. [ Method] A field experiment with two super hybrid cultivars (Zhunliangyou527, Qyou 6) and CK(Ⅱ you838) was conducted in 2011, and dry matter accumulation (DMA) and nitrogen, phosphorus and potassium accumulation (NA, PA, KA) were measured. The dynamic equations of relative dry matter accumulation (DMAR) and nitrogen, phosphorus and potassium accumulation (Nar, Par, Kar) were established with the normalized DMA, normalized NA, PK and KA and normalized growth time, and the dynamic characteristics of DMA and NA, PA, KA changes were analyzed based on the relative equations. [Result] Gompertz simulated better than the other equations for the DMA and nutrient dynamic accumulation characteristics of super hybrid rice. The equations were validated with field experimental data of 2009 and 2011.The NRMSE of DMA simulation were relatively smaller, and R2 values were above 0.9820. The accuracies were about 1, and the NS values were above 0.9530. Validation for the nutrient accumulation equation showed that the model simulated well. The R2, k and NS were all about 1. The analysis of growth characteristics of super hybrid rice showed that the rate of DMA in super hybrid rice was slightly higher than CK at earlier stage and significantly at last stage. The maximum rate of DMA of super hybrid rice was from boot stage to heading stage. The initial of DMA rapid growth stage for super hybrid rice were lower than the CK. The duration of rapid growth period of DMA of super hybrid rice was 71-75 d, which was 16-19 d longer than the CK and the ratio of DMA of rapid growth period in total DMA of super hybrid rice was 4.47%-11.25% higher than that of the CK. The maximum NA rate of super hybrid rice was in 10 d before boot stage. The NA (nitrogen accumulation) rapid growth stage was from 12 d before

  15. 一个新的水稻半矮化小穗突变体的遗传分析与基因定位%Genetic Analysis and Gene Mapping of a New Semi-Dwarf and Small Panicle Mutant in Rice

    汪庆; 汪得凯; 陶跃之

    2011-01-01

    A semi-dwarf and small panicle mutant was obtained from a japonica rice variety Zhonghua 11 through T-DNA transformation. The mutant, characterized by semi-dwarf plant, abnormal small and semi-enclosed panicle* and poor growth potential was designated as sd-sp2(semi-dwarf and small panicle 2). Genetic analysis indicated that the mutant was controlled by a single recessive gene. A genetic linkage map was constructed using an Fz mapping population derived from a cross between the sd-sp2 mutant and an indica variety Longtefu B on chromosome 6. The gene was finally located on a 116-kb region between the STS markers RH6-32 and RH6-40.where 14 ORFs were predicted based on Rice Genome Annotation.%从粳稻中花11转基因后代中发现了一个半矮化小穗突变体,表现为植株半矮化、生长势弱、半包茎穗、穗型变小等特点,将其命名为sd-sp2(semi-dwarf and small panicle 2).遗传分析显示,该突变体表型受1对隐性核基因控制.以sd-sp2突变体为母本与龙特甫B杂交构建F2分离群体,将该基因定位在水稻第6染色体的RH6-32和RH6-40之间的116 kb的物理距离内.通过水稻基因组注释系统在此区域预测到14个开放阅读框,未发现与已报道穗型发育相关基因的同源基因.

  16. A decrease in phytic acid content substantially affects the distribution of mineral elements within rice seeds.

    Sakai, Hiroaki; Iwai, Toru; Matsubara, Chie; Usui, Yuto; Okamura, Masaki; Yatou, Osamu; Terada, Yasuko; Aoki, Naohiro; Nishida, Sho; Yoshida, Kaoru T

    2015-09-01

    Phytic acid (myo-inositol hexakisphosphate; InsP6) is the storage compound of phosphorus and many mineral elements in seeds. To determine the role of InsP6 in the accumulation and distribution of mineral elements in seeds, we performed fine mappings of mineral elements through synchrotron-based X-ray microfluorescence analysis using developing seeds from two independent low phytic acid (lpa) mutants of rice (Oryza sativa L.). The reduced InsP6 in lpa seeds did not affect the translocation of mineral elements from vegetative organs into seeds, because the total amounts of phosphorus and the other mineral elements in lpa seeds were identical to those in the wild type (WT). However, the reduced InsP6 caused large changes in mineral localization within lpa seeds. Phosphorus and potassium in the aleurone layer of lpa greatly decreased and diffused into the endosperm. Zinc and copper, which were broadly distributed from the aleurone layer to the inner endosperm in the WT, were localized in the narrower space around the aleurone layer in lpa mutants. We also confirmed that similar distribution changes occurred in transgenic rice with the lpa phenotype. Using these results, we discussed the role of InsP6 in the dynamic accumulation and distribution patterns of mineral elements during seed development.

  17. Acumulação de silício em arroz em diferentes condições de pH da rizosfera Silicon accumulation in rice in different rhizosphere pH conditions

    Lilian Aparecida de Oliveira

    2007-08-01

    Full Text Available A quantidade de Si acumulada pelas plantas depende do teor de Si disponível, e este, do pH do solo. É possível que a absorção e acumulação de Si em gramíneas possam estar associadas ao pH rizosférico. Este trabalho teve como objetivo estudar o efeito do pH de rizosfera na disponibilidade do Si no solo, na acumulação por plantas de arroz de sequeiro (vr. Epagri 109 e na produção de massa seca. Para isso, instalou-se um ensaio em casa de vegetação, em parcela subdividida, no esquema fatorial 5 x 2. Os cinco tratamentos (TR foram constituídos de dose única de N (200 mg kg-1, aplicada nas seguintes relações de N-NH4+e N-NO3-: TR1 = 0,0:1,0; TR2 = 0,25:0,75; TR3 = 0,50:0,50; TR4 = 0,75:0,25; e TR5 = 1,0:0,0. O fator subparcela consistiu da aplicação de 200 mg kg-1 de Si. As fontes de N usadas foram nitrato de cálcio e sulfato de amônio, e a fonte de Si foi o tetracloreto de Si, aplicadas em uma amostra de Neossolo Quartzarênico. Para inibir a nitrificação foram utilizados 10 mg kg-1 de nitrapirina nos tratamentos em que amônio foi empregado. Os valores de pH rizosférico decresceram proporcionalmente ao aumento da concentração de N-NH4+ e influenciaram de forma significativa o teor de Si no solo: quanto maior o pH rizosférico, maior a disponibilidade de Si e maior a absorção pela planta de arroz.The amount of silicon accumulated by plants depends on the concentration of available silicon, and this of the soil pH. Silicon absorption and accumulation in grasses is possibly associated with the rhizosphere pH. This study evaluated the effect of rhizosphere pH on Si absorption and accumulation in upland rice (Epagri 109 vr.. The experiment was carried out in a greenhouse in a 5 x 2 factorial design. The five treatments (TR consisted of a single N dose (200 mg kg-1 applied in the following N-NH4+ / N-NO3- proportions: TR1 = 0.0:1.0; TR2 = 0.25:0.75; TR3 = 0.50:0.50; TR4 = 0.75:0.25; TR5 = 1.0:0.0. The subplots were

  18. Ethylene Responses in Rice Roots and Coleoptiles Are Differentially Regulated by a Carotenoid Isomerase-Mediated Abscisic Acid Pathway[OPEN

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-01-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice. PMID:25841037

  19. 水稻细卷叶突变体nrl2(t)的遗传分析和基因定位%Genetic Analysis and Gene Mapping of a Novel Narrow and Rolled Leaf Mutant nrl2(t) in Rice (Oryza sativa L.)

    王德仲; 桑贤春; 游小庆; 王增; 王秋实; 赵芳明; 凌英华; 李云峰; 何光华

    2011-01-01

    研究调控水稻叶片发育基因对水稻功能基因组学和株型改良有着重要的意义.本研究从籼稻恢复系缙恢10号的EMS突变体库中发现一个水稻新型突变体,命名为nrl2(t).该突变体叶片卷曲、变细、伸长,茎秆变细,抽穗期提前,叶绿素含量增高,孕穗期剑叶生长素含量降低,而幼穗中生长素含量有所提高.遗传分析表明该性状受一对隐性基因控制.利用SSR标记将该基因定位于第3染色体SSR标记s3RM1和s3RM3之间,物理距离约为114kb.研究结果为该基因的克隆及进一步揭示细叶卷曲形成的分子机理奠定了基础.%Study of the genes which regulate leaf development is significant in rice functional genomics research and molecular breeding. In the present study, a novel rolled and narrow leaf mutant was obtained from the rice (Oryza saliva L.) restorer line Jinhui 10 treated by ethyl methyl sulphonate (EMS), named nrl2(t). The mutant exhibited narrow/semi-rolled and elongate leaves, earlier flowering, thinner stalk, higher pigment content and higher plant height compared with the control. The indole-3-acetic acid (IAA) content relatively reduced in the flag leaf compared to that of wild type, but increased in the young panicle at the heading stage. Genetic analysis indicated that the mutant was controlled by a single recessive gene, located on the chromosome 3 between SSR markers S3RM1 and s3RM3, delimiting to a 114 kb region. These results will lay a good foundation for molecular cloning and functional analysis of the NRL2(t).

  20. Ultrastructure and Gene Mapping of the Albino Mutant al12 in Rice (Oryza sativa L.)%水稻(Oryza sativa L.)苗期低温白化突变体al12的超微结构与基因定位

    夏九成; 王玉平; 马炳田; 殷兆晴; 郝铭; 孔德伟; 李仕贵

    2006-01-01

    Seedling albino mutation resistant to low temperature is an adaptability of rice (Oryza sativa L.) to cold. The mutant, a conditional expression controlled by development and temperature, differs from other albino mutants. The chlorophyll content of the mutant was measured using a portable chlorophyll meter, and the ultrastructure of the chloroplast was observed using a transmission electron microscope. Chlorophyll content was 1.2 SPAD, and the chloroplast did not develop, with only small vesicle-like structures. A segregation analysis of the reciprocal crosses between the albino mutation line with the rice line 9311demonstrated that the albino trait was controlled by a single recessive gene, which was flanked by SSR markers RM5068 and RM3702 on the short arm of chromosome 8 with a distance of 0.5-1.1 cM and 4.9 cM, respectively. This gene was mapped within a 6 cM interval region and was tentatively referred to as all2.%水稻苗期低温白化突变是水稻在发育早期对低温胁迫的一种适应性,是一种受发育和温度控制的条件表达,它与其他水稻白化突变有本质的不同.本研究利用便携式叶绿素测量仪测定了白化时期植株的叶绿素含量和用透射电镜观察了叶绿体的结构变化.结果发现叶绿素平均含量仅为1.2(SPAD),而叶绿体也不能正常发育仅有囊泡状结构.通过与9311的正反交实验及子代的分离表现证明该性状受一个隐性核基因的控制.另外利用SSR分子标记技术将该基因定位在第8染色体上,两侧最近的SSR标记RM5068和RM3702分别距基因0.5~1.1 cM和4.9 cM,基因被定位在约6个cM的区间内.我们将该基因暂时命名为al12.

  1. OsDMI3 Is a Novel Component of Abscisic Acid Signaling in the Induction of Antioxidant Defense in Leaves of Rice

    Ben Shi; Lan Ni; Aying Zhang; Jianmei Cao; Hong Zhang; Tingting Qin; Mingpu Tan; Jianhua Zhang; Mingyi Jiang

    2012-01-01

    Ca2+ and calmodulin (CaM) have been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense.However,it is unknown whether Ca2+/CaM-dependent protein kinase (CCaMK) is involved in the process.In the present study,the role of rice CCaMK,OsDMI3,in ABA-induced antioxidant defense was investigated in leaves of rice (Oryza sativa) plants.Treatments with ABA,H2O2,and polyethylene glycol (PEG) induced the expression of OsDMI3 and the activity of OsDMI3,and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress.Subcellular localization analysis showed that OsDMI3 is located in the nucleus,the cytoplasm,and the plasma membrane.The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference (RNAi) silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase (SOD) and catalase (CAT).Further,the oxidative damage induced by higher concentrations of PEG and H2O2 was aggravated in the mutant of OsDMI3.Moreover,the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling,but the initial H2O2 production induced by ABA is not dependent on the activation of OsDMI3 in leaves of rice plants.Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.

  2. Effect of Cry1Ab Gene on Photosynthetic Characteristics and Photosynthate Accumulation of Rice%转Bt (Cry1Ab)基因对水稻光合特性及光合产物积累的影响

    刘微; 王树涛; 陈英旭; 吴伟祥

    2011-01-01

    [目的]明确外源Bt基因插入对水稻倒1叶光合速率及光合作用相关生理特性的影响.[方法]以转Bt基因水稻及亲本水稻为试材,研究盆栽及田间条件下转Bt基因及亲本水稻苗期、拔节期、抽穗期和成熟期倒1叶光合特性及其相关光合酶活性、光合产物积累的动态变化.[结果]转Bt基因及亲本水稻生理活动峰值均出现在拔节期.与亲本水稻相比,转Bt基因水稻苗期叶片净光合速率显著低于亲本;而拔节期和抽穗期,转Bt基因水稻倒1叶净光合速率、叶绿素含量和乙醉酸氧化酶活性显著高于亲本水稻(P0.05).[结论]与亲本水稻相比,外源Bt基因的插入对水稻叶片光合特性产生短暂影响,但这种影响不具有持续性.%[Objective] The objective of this study was to identify the effect of exogenous Cry1Ab gene on photosynthetic characteristics in Bt transgenic rice. [ Method] Pot and field experiments were conducted with Bt transgenic and non-Bt transgenic rice at seedling, booting, heading and maturing stages, photosynthesis and enzyme activities of reciprocal first leaf were analyzed.[Result] The results showed that all of the maximum net photosynthetic rate (Pn) appeared at booting stage. At seedling stage, the Pn of transgenic Bt rice was significantly lower than that of non-Bt transgenic rice. However, Ph, total chlorophyll content and activity of glycolate oxidase in Bt transgenic rice were significantly higher than those in non-Bt transgenic rice at booting and heading stages. Moreover, intercellular CO2 concentration of Bt transgenic rice at booting stage was significantly higher than that of non-Bt transgenic rice. The significant changes of stomatal conductance, transpiration rate, intercellular CO2 concentration, the total chlorophyll content and the enzyme activities in the leaves of Bt transgenic and non-Bt transgenic rice were not detected at maturing stage. [ Conclusion ] Compared with non-Bt transgenic rice

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

    Matsuno, Koya; Fujimura, Tatsuhito

    2014-03-01

    A pathway of phytic acid (PA) synthesis in plants has been revealed via investigations of low phytic acid mutants. However, the regulation of this pathway is not well understood because it is difficult to control the environments of cells in the seeds, where PA is mainly synthesized. We modified a rice suspension culture system in order to study the regulation of PA synthesis. Rice cells cultured with abscisic acid (ABA) accumulate PA at higher levels than cells cultured without ABA, and PA accumulation levels increase with ABA concentration. On the other hand, higher concentrations of sucrose or inorganic phosphorus do not affect PA accumulation. Mutations in the genes RINO1, OsMIK, OsIPK1 and OsLPA1 have each been reported to confer low phytic acid phenotypes in seeds. Each of these genes is upregulated in cells cultured with ABA. OsITPK4 and OsITPK6 are upregulated in cells cultured with ABA and in developing seeds. These results suggest that the regulation of PA synthesis is similar between developing seeds and cells in this suspension culture system. This system will be a powerful tool for elucidating the regulation of PA synthesis.

  4. Proteome Analysis of Rice Root Proteins Regulated by Gibberellin

    Setsuko Komatsu; Hirosato Konishi

    2005-01-01

    To gain an enhanced understanding of the mechanism by which gibberellins (GAs) regulate the growth and development of plants, it is necessary to identify proteins regulated by GA. Proteome analysis techniques have been applied as a direct,effective, and reliable tool in differential protein expressions. In previous studies,sixteen proteins showed differences in accumulation levels as a result of treatment with GA3, uniconazole, or abscisic acid (ABA), and/or the differences between the GA-deficient semi-dwarf mutant, Tan-ginbozu, and normal cultivars. Among these proteins, aldolase increased in roots treated with GA3, was present at low levels in Tan-ginbozu roots, and decreased in roots treated with uniconazole or ABA. In a root elongation assay, the growth of aldolase-antisense transgenic rice was half of that of vector control transgenic rice. These results indicate that increases in aldolase activity stimulate the glycolytic pathway and may play an important role in the GA-induced growth of roots. In this review, we discuss the relationship among GA, aldolase, and root growth.

  5. Research progress in studying molecular physiological mechanisms of low Cd accumulation in rice grain%稻米Cd低积累分子生理机制的研究进展

    叶瑶瑶; 王飞娟; 俞娇; 石晓柳; 朱诚; 蔡冲

    2013-01-01

    随着我国国民经济持续快速增长,农田生态系统重金属污染日趋严重,Cd是环境中运移活跃、对生物和人类毒性较大的重金属元素.稻米是我国人民的主要食物来源,而水稻对Cd具有较强的吸收能力,因而稻米的安全性成为大家关注的问题.本文主要介绍了近几年来在水稻稻米低积累分子生理机制方面的研究进展.%With sustained rapid development of the national economy, heavy metal pollution of farmland ecosystem is becoming more serious. Cd is active transport in the environment, and has large toxicity to organism and human. Rice is the major source of food for Chinese, while rice has a strong absorption capacity of Cd,and thus rice security has become an issue of concern. This paper reviewed the research progress on molecular physiological mechanisms of low-Cd rice grain in recent years.

  6. Iron biofortification of Myanmar rice

    May Sann Aung

    2013-05-01

    Full Text Available Iron (Fe deficiency causes elevates human mortality rates, especially in developing countries. In Myanmar, the prevalence of Fe-deficient anemia in children and pregnant women are 75% and 71%, respectively. Myanmar people have one of the highest per capita rice consumption rates globally. Consequently, production of Fe-biofortified rice would likely contribute to solving the Fe-deficiency problem in this human population. To produce Fe-biofortified Myanmar rice by transgenic methods, we first analyzed callus induction and regeneration efficiencies in 15 varieties that are presently popular because of their high yields and/or qualities. Callus formation and regeneration efficiency in each variety was strongly influenced by types of culture media containing a range of 2,4-dichlorophenoxyacetic acid concentrations. The Paw San Yin variety, which has a high Fe content in polished seeds, performed well in callus induction and regeneration trials. Thus, we transformed this variety using a gene expression cassette that enhanced Fe transport within rice plants through overexpression of the nicotianamine synthase gene HvNAS1, Fe flow to the endosperm through the Fe(II-nicotianamine transporter gene OsYSL2, and Fe accumulation in endosperm by the Fe storage protein gene SoyferH2. A line with a transgene insertion was successfully obtained. Enhanced expressions of the introduced genes OsYSL2, HvNAS1, and SoyferH2 occurred in immature T2 seeds. The transformants accumulated 3.4-fold higher Fe concentrations, and also 1.3-fold higher zinc concentrations in T2 polished seeds compared to levels in non-transgenic rice. This Fe-biofortified rice has the potential to reduce Fe-deficiency anemia in millions of Myanmar people without changing food habits and without introducing additional costs.

  7. Stamen specification and anther development in rice

    ZHANG DaBing; WILSON Zoe A

    2009-01-01

    Male reproductive development is a complex biological process which includes the formation of the stamen with differentiated anther tissues, in which microspores/pollens are generated, then anther dehiscence and subsequently pollination. Stamen specification and anther development involve a number of extraordinary events such as meristem transition, cell division and differentiation, cell to cell communication, etc., which need the cooperative interaction of sporophytic and gametophytic genes. The advent of various tools for rice functional gene identification, such as complete genome sequence, genome-wide microarrays, collections of mutants, has greatly facilitated our understanding of mechanisms of rice stamen specification and anther development. Male sterile lines are critical for hybrid rice breeding, therefore understanding these processes will not only contribute greatly to the basic knowledge of crop developmental biology, but also to the development of new varieties for hybrid rice breeding in the future.

  8. Rice methylmercury exposure and mitigation: a comprehensive review.

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  9. Influences of mechanical sowing and transplanting on nitrogen accumulation, distribution and C/N of hybrid rice cultivars%机械化播栽对杂交稻氮素积累分配及碳氮比的影响

    刘利; 雷小龙; 黄光忠; 刘代银; 任万军

    2014-01-01

    累能力,有利于杂交稻氮素高效吸收利用和植株体内碳氮代谢的平衡,因而获得高产高效。%[Objectives]The nitrogen uptake and accumulation are an important foundation for yield formation in rice. Along with the transfer of rural labor to the cities, the pace of rice production mechanization in China consequently grows rapidly. The growth, development, and the environment of each growth stage of hybrid rice have changed in the mechanical sowing and transplanting methods. However, less research has been done on how the mechanical sowing and transplanting methods influence the nitrogen absorption and utilization characterization. The hybrid indica rice ( F you 498 ) is used in the experiments to explore the characteristics of nitrogen uptake, utilization and C/N. [Methods] Two factorial split-plot designs with three replications were used in this experiment, the main plots consisted of three sowing and transplanting methods ( mechanical direct seeding, mechanical transplanting, and artificial transplanting), the subplots were subjected two seeding number per hill ( low seeding number per hill and high seeding number per hill) . The effects of sowing and transplanting methods and seedling number per hill on nitrogen accumulation, distribution and C/N were investigated. [Results]Mechanical sowing and transplanting methods had apparent effects on the nitrogen uptake, utilization, and C/N of hybrid rice. The mechanical direct seeding improved the nitrogen content at the jointing and maturity periods, and the capabilities of nitrogen accumulation in plants of rice at the maturity period. The nitrogen content at the heading period in the mechanical transplanting was higher than the artificial transplanting, the mechanical transplanting could keep high nitrogen accumulation of rice at the jointing period. The nitrogen translocation, apparent nitrogen translocation rate of rice leaves and stem-sheath, nitrogen transfer rate, nitrogen use

  10. Protein disulfide isomerase-like protein 1-1 controls endosperm development through regulation of the amount and composition of seed proteins in rice.

    Yeon Jeong Kim

    Full Text Available Protein disulfide isomerase (PDI is a chaperone protein involved in oxidative protein folding by acting as a catalyst and assisting folding in the endoplasmic reticulum (ER. A genome database search showed that rice contains 19 PDI-like genes. However, their functions are not clearly identified. This paper shows possible functions of rice PDI-like protein 1-1 (PDIL1-1 during seed development. Seeds of the T-DNA insertion PDIL1-1 mutant, PDIL1-1Δ, identified by genomic DNA PCR and western blot analysis, display a chalky phenotype and a thick aleurone layer. Protein content per seed was significantly lower and free sugar content higher in PDIL1-1Δ mutant seeds than in the wild type. Proteomic analysis of PDIL1-1Δ mutant seeds showed that PDIL1-1 is post-translationally regulated, and its loss causes accumulation of many types of seed proteins including glucose/starch metabolism- and ROS (reactive oxygen species scavenging-related proteins. In addition, PDIL1-1 strongly interacts with the cysteine protease OsCP1. Our data indicate that the opaque phenotype of PDIL1-1Δ mutant seeds results from production of irregular starch granules and protein body through loss of regulatory activity for various proteins involved in the synthesis of seed components.

  11. The Phenotype of a Dwarf Mutant in Indica Rice Tm049 and Its Responses to Gibberellin%籼稻矮杆突变体Tm049的表型分析及其对外源赤霉素的响应

    黄秀芝; 丁海东; 梁建生

    2012-01-01

    Abstract: A rice dwarf mutant Tm049 from Indica rice 9311 was obtained in the progeny after 60Co-rays inducement, and the phenotype, internode cell structure and physiological characteristics of Tm049 were investigated. The results showed that Tm049 exhibited dwarf, little dark green and short and wide leaves, fewer tillers, spike erect, small and round grains, and belonging to the dn-type dwarf. The volume and number of cellsin 1st and 2nd internodes were changed. The sensitivity of the second leaf sheaths Tm049 to exogenous gibberellin (GA3) was reduced. The endogenous GA3 levels of Tm049 was slightly higher than that of wild--type 9311. It could be speculated that the mutant may be related to the deletion of the GA signaling pathway. These results will lay a foundation for positional cloning the dwarf gene, functional analysis and molecular marker- assisted selection of new varieties.%利用60Coγ射线辐照籼稻93-11,获得一个性状稳定的矮化突变体材料Tm049,对其表型、节间细胞结构及生理特性方面进行了分析。研究结果表明,Tm049植株矮化、叶色略深且短而宽、分蘖少、穗型直立状、籽粒小而圆、属于dn型矮杆;第一节间和第二节间细胞体积和数目发生变化;第二叶鞘对外源赤霉素(GA3)敏感性降低;内源GA3水平略高于野生型.推测该突变体可能与GA的信号途径缺失有关.研究结果为今后该基因的定位克隆、功能分析及分子标记辅助培育理想株型的新品种奠定了研究基础.

  12. IN PLANTA ASSAY OF HYGROMYCIN SUSCEPTIBILITY AND MUTANT SCREENING IN RICE AT HEADING STAGE%水稻穗期活体植株对潮霉素的敏感性分析及突变体选育

    富昊伟; 沈圣泉; 李友发; 陈洋; 马兴华; 舒小丽; 舒庆尧

    2012-01-01

    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 ofdifferent concentrations (25 - 100mg/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 50mg/ L hygromycin, and the more spots were occurred with the higher hygromycin solution. There were 21.1 and 19.2 spots per cm^2 on flag leaves of indica varieties Jiayou 99 and C10, respectively; while 27.6% and 23.5% grains were yellow- brown in the two 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 11.9% 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 β-rays treated M2 population of KMD1 was sprayed with 100mg/L hygromycin solution at heading stage and 42 plants were screened out with toxic symptoms in leaves and panicles from 120,000 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 100mg/L hygromycin solution at heading stage would lead to visually apparent toxic symptoms in susceptibility rice

  13. Contribution of chloroplast biogenesis to carbon-nitrogen balance during early leaf development in rice.

    Kusumi, Kensuke; Hirotsuka, Shoko; Shimada, Hiroshi; Chono, Yoko; Matsuda, Osamu; Iba, Koh

    2010-07-01

    Chloroplast biogenesis is most significant during the changes in cellular organization associated with leaf development in higher plants. To examine the physiological relationship between developing chloroplasts and host leaf cells during early leaf development, we investigated changes in the carbon and nitrogen contents in leaves at the P4 developmental stage of rice, during which leaf blade structure is established and early events of chloroplast differentiation occur. During the P4 stage, carbon content on a dry mass basis remained constant, whereas the nitrogen content decreased by 30%. Among carbohydrates, sucrose and starch accumulated to high levels early in the P4 stage, and glucose, fructose and cellulose degradation increased during the mid-to-late P4 stage. In the chloroplast-deficient leaves of the virescent-1 mutant of rice, however, the carbon and nitrogen contents, as well as the C/N ratio during the P4 stage, were largely unaffected. These observations suggest that developing rice leaves function as sink organs at the P4 stage, and that chloroplast biogenesis and carbon and nitrogen metabolism in the leaf cell is regulated independently at this stage.

  14. Phytase activity in brown rice during steeping and sprouting

    Ou, K.; Cheng, Y.; Xing, Y.; Lin, L.; Nout, M.J.R.; Liang, J.

    2011-01-01

    Phytase in brown rice will be activated and accumulated during seed germination. Changes of phytase activity in brown rice during two stages of germination (steeping and sprouting) affected by process conditions were studied. It was shown that steeping led to significant decrease of phytase activity

  15. 水稻淡绿叶突变体 HM133的遗传分析与基因定位%Genetic Analysis and Gene Mapping of a Pale Green Leaf Mutant HM133 in Rice

    施勇烽; 贺彦; 郭丹; 吕向光; 黄奇娜; 吴建利

    2016-01-01

    The pale green leaf mutant HM133 was identified from an EMS-induced IR64 mutant bank.The contents of photosynthetic pigments including chlorophyll and carotenoid of HM133 were reduced significantly at 6 weeks and 1 5 weeks after sowing when compared with IR64.The net photosynthetic rate of HM133 was considerably lower than that of the wild-type IR64 at heading stage while the stomatal conductance was apparently increased.The agronomic traits including plant height,number of filled grain per panicle and seed-setting rate decreased significantly in the mutant compared with the wild-type.In addition,the mutant exhibited a less number of grana,irregular arrangement of thylakoid layer in the chloroplast at the tillering stage.Genetic and mapping analysis showed that the pale green phenotype was controlled by a single recessive gene located in the long arm of chromosome 3 between SSR markers RM143 and RM3684.The interval contains an ORF OsChlD encoding magnesium-chelatase D subunit.Sequence analysis revealed that the mutant allele carried a nucleotide substitution from G to A in the tenth exon of OsChlD , which led to the substitution of glutamic acid for arginine acid.Therefore,it is deduced that OsChlD is the candidate gene controlling the pale green leaf phenotype of HM133 .%EMS 诱导籼稻品种 IR64获得淡绿叶突变体 HM133.与野生型 IR64相比,HM133播种后的第6周和第15周的光合色素含量以及抽穗期的净光合速率显著降低,气孔导度则明显上升;此外,突变体株高、每穗实粒数和结实率等农艺性状也较野生型显著下降.叶绿体超微结构分析表明,分蘖期 HM133类囊体基粒片层形状不规则,堆叠凌乱、排列疏松.遗传分析表明 HM133淡绿叶性状受单隐性核基因控制.通过分子标记将该基因定位于第3染色体长臂 RM143和 RM3684之间.该区间内包含编码镁螯合酶 D 亚基的基因 OsCHLD .序列分析表明 HM133中该基因第10外显子上有一个从 G

  16. Effects of alginate-derived oligosaccharides synergistic urea on the photosynthetic characteristics and accumulation of carbon metabolites in rice%海藻寡糖增效尿素对水稻光合特性及碳代谢产物积累的影响

    张运红; 孙克刚; 杜君; 和爱玲; 张起义

    2016-01-01

    Pot experiments were used to study the effects of alginate-derived oligosaccharide ( ADO) synergistic urea on photo-synthetic characteristics, key enzymes activities and carbon metabolites accumulation of rice ( Oryza. Sativa L. ) . The results showed that net photosynthetic rate ( Pn ) , stomatal conductance ( Gs ) , intercellular CO2 concentration ( Ci ) and water use efficiency ( WUE) of rice under ADO synergistic urea treatment were increased, and stomatal limitation value ( Ls ) was de-creased, compared with ordinary urea. Chlorophyll content and ribulose-1, 5-bisphosphate-caboxylase ( Rubisco) activity were also significantly raised. At booting, full heading and maturing stages, sucrose phosphate synthase ( SPS) , sucrose syn-thase (SUS) and ADP-glucose pyrophosphorylase (ADPase) activity in leaves or grain of rice were significantly enhanced, thus contributing to the accumulation of sucrose and starch in grain. Aboveground and belowground biomass were also signifi-cantly increased at all the four growth stages. Rice yield of ADO synergistic urea treatment was significantly raised by 9. 32%compared with the control, and was higher than that of ordinary urea treatment by 3. 94%.%采用盆栽试验,研究了海藻寡糖增效尿素对水稻光合特性、碳代谢关键酶活性及相关产物积累的影响。结果表明,和普通尿素相比,海藻寡糖增效尿素处理的水稻净光合速率( Pn )、气孔导度( Gs )、胞间CO2浓度(Ci)和水分利用效率(WUE)有所增加,气孔限制值(Ls)有所降低,叶绿素含量和核酮糖-1,5-二磷酸羧化加氧酶(Rubisco)活性显著提高。拔节期、齐穗期和成熟期叶中和籽粒中蔗糖磷酸合成酶(SPS)、蔗糖合成酶( SUS)和腺苷二磷酸葡萄糖焦磷酸化酶( ADPase)活性显著增强,从而促进籽粒中蔗糖和淀粉积累;地上部和地下部生物量在4个生育期也均显著增加,籽粒产量显著提高,其中较对照增加9.32%,较普通尿素处理增加3.94

  17. Host Active Defense Responses Occur within 24 Hours after Pathogen Inoculation in the Rice Blast System

    WANG Zhong-hua; JIA Yu-lin; LIN Hui; Adair INTERN; Barbara VALENT; J. Neil RUTGER

    2007-01-01

    Phenotypical, cytological and molecular responses of rice to the fungus Magnaporthe grisea were studied using rice cultivars and lesion mimic plants. The cultivar Katy was susceptible to several virulent M. grisea isolates, and a Sekiguchi like-lesion mimic mutant of Katy (LmmKaty) showed enhanced resistance to these isolates. Lesion mimic phenotype of LmmKaty was rapidly induced by virulent M. grisea isolates or by avirulent ones 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, not evident in the compatible interaction. Autofluorescence was also observed in LmmKaty 20 h after pathogen inoculation, indicating that rapid cell death is a mechanism of LmmKaty to restrict pathogen invasion. Rapid accumulations of defense related (DR) gene transcripts, phenylalanine ammonia lyase and β-glucanase,were observed beginning at 6 h and were obvious at 16 h and 24 h after inoculation in an incompatible interaction. Rapid transcript accumulations of PR-1 and chitinase had occurred by 24 h after inoculation in an incompatible interaction.Accumulations of these transcripts were delayed in the 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. It is suggested that the autofluorescence and expression of the DR genes after heavy inoculation are important cytological and molecular markers respectively for early determination of the host response to M. grisea in the rice blast system.

  18. Analysis on Dry Matter Production Characteristics of Super Hybrid Rice

    2008-01-01

    Six middle-season indica hybrid rice combinations,including five super hybrid rice combinations with the high yield about 10.5 t/ha and a check hybrid rice combination Shanyou 63 with a yield potential about 9.5 t/ha,were used as materials to study the dry matter production characteristics.The super hybrid rice showed a high ability in dry matter production and accumulation and its yield enhanced with the increase of dry matter accumulation.The advantage period of dry matter production in the super hybrid rice was mainly at the middle and late growth stages compared with the check.The grain yield had no significant correlation with the dry matter accumulation before the elongation stage while had a significantly positive correlation with the dry matter accumulation from the elongation to maturity stages in super hybrid rice.There were more dry matter in vegetative organs at the heading stage in the super hybrid rice but its contribution to yield (apparent conversion percentage) was averagely 4.3 percent points lower than that in the check.For crop growth rate (CGR),the comparative advantage of super hybrid rice was at the middle and late stages,especially after flowering.Moreover,as the rising of leaf area index (LAI) and leaf area duration (LAD),CGR enhanced.The total LAD and the mean of LAD per day of super hybrid rice was about 14.79% and 10.31% higher than those of the check,respectively.The results indicate that the high yield of super hybrid rice mostly comes from the products of photosynthesis after heading,which is shown by the increased CGR at middle and later stages.It is suggested that LAD character might be used to better explain the advantage in the dry matter production of super hybrid rice than LAI.

  19. Genetic shift in local rice populations during rice breeding programs in the northern limit of rice cultivation in the world.

    Fujino, Kenji; Obara, Mari; Ikegaya, Tomohito; Tamura, Kenichi

    2015-09-01

    The rapid accumulation of pre-existing mutations may play major roles in the establishment and shaping of adaptability for local regions in current rice breeding programs. The cultivated rice, Oryza sativa L., which originated from tropical regions, is now grown worldwide due to the concerted efforts of breeding programs. However, the process of establishing local populations and their origins remain unclear. In the present study, we characterized DNA polymorphisms in the rice variety KITAAKE from Hokkaido, one of the northern limits of rice cultivation in the world. Indel polymorphisms were attributed to transposable element-like insertions, tandem duplications, and non-TE deletions as the original mutation events in the NIPPONBARE and KITAAKE genomes. The allele frequencies of the KITAAKE alleles markedly shifted to the current variety types among the local population from Hokkaido in the last two decades. The KITAAKE alleles widely distributed throughout wild rice and cultivated rice over the world. These have accumulated in the local population from Hokkaido via Japanese landraces as the ancestral population of Hokkaido. These results strongly suggested that combinations of pre-existing mutations played a role in the establishment of adaptability. This approach using the re-sequencing of local varieties in unique environmental conditions will be useful as a genetic resource in plant breeding programs in local regions.

  20. Caracterização de famílias mutantes de arroz para tolerância ao frio nos períodos vegetativo e reprodutivo Characterization of rice families for cold tolerance in the vegetative and reproductive phases

    Andreza Figueirola Martins

    2007-01-01

    Full Text Available As temperaturas baixas que ocorrem durante o cultivo do arroz na Região Sul do Brasil causam prejuízos ao rendimento e à qualidade dos grãos de arroz. Genótipos tolerantes a baixas temperaturas seriam uma alternativa para minimizar tais prejuízos. Desse modo, o presente trabalho teve como objetivo avaliar a tolerância ao frio em famílias mutantes de arroz (geração M4 nos períodos, vegetativo e reprodutivo, como forma de identificação de variabilidade genética para o caráter. Para a avaliação das famílias mutantes quanto à tolerância ao frio, no período vegetativo, foram utilizadas 10 sementes de cada família colocadas em bandejas celuladas, sendo as plântulas mantidas em casa de vegetação à temperatura de 13 ºC por 10 dias em sala climatizada, com fotoperíodo de 12 horas. A avaliação do período reprodutivo consistiu na aplicação de frio na antese, sendo caracterizada por um estresse de 15 ºC por sete dias. Pelos resultados verificou-se que no período vegetativo, seis famílias tiveram 0-20% de redução na estatura, com um elevado grau de tolerância. Para o período reprodutivo não foram encontradas famílias com tolerância superior à testemunha diamante.Low temperatures that occur during the cultivation of rice in the Southern region of Brazil cause reductions in to the yield and quality of the rice grain. Genotypes tolerant to low temperatures would be an alternative to minimize these problems. In the present work cold tolerance was evaluated in rice families (M4 generation in the vegetative and reproductive phases, in order to identify possible genetic variability. For the evaluation in the vegetative stage, 10 seeds from each family were placed in cell trays and kept at 13 ºC for 10 days in controlled chamber with 12 hour day light. The evaluation at the reproductive stage consisted of the application of low temperature at anthesis, by a stress of 15 ºC for 7 days. The results suggest that in the

  1. Antimicrobial Activity of UV-Induced Phenylamides from Rice Leaves

    Hye Lin Park

    2014-11-01

    Full Text Available Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae. In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus. UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae, blight (Xanthomonas oryzae pv. oryzae and leaf streak (X. oryzae pv. oryzicola diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens.

  2. Rice methylmercury exposure and mitigation: a comprehensive review

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, price percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  3. 增施钾肥对冷浸田水稻生理及植株铁吸收累积的影响%Effects of Potassium Fertilizer Increasement on Rice Physiology and Iron Accumulation in Cold-waterlogged Paddy Field

    李清华; 王飞; 林诚; 何春梅; 李昱; 钟少杰; 林新坚

    2015-01-01

    有效钾缺乏、Fe2+毒害是影响冷浸田水稻产量的重要因素。通过田间试验,研究不同钾肥用量对冷浸田水稻生长生理、植株铁累积及产量的影响。结果表明:与不施钾肥相比,增施钾肥孕穗期水稻叶绿素 a+b 和光合速率分别增加10.27%~28.40%、11.40%~29.31%,孕穗期与成熟期根系活力分别提高10.53%~22.67%、27.71%~48.62%,成熟期稻谷产量增加4.93%~14.77%。施肥能促进植株体内钾的吸收和抑制根系对铁的累积。在水稻分蘖期、孕穗期与成熟期,根系铁含量分别降低0.04~0.73、0.33~0.95及0.62~0.82个百分点,此外在分蘖期水稻根系钾与铁含量呈极显著负相关(r =-0.86**)。增施钾肥能够提高根系活力,增强光合作用,促进碳水化合物合成与运输,同时较好地抑制铁的累积,因此增施钾肥是发挥冷浸田生产潜力的有效措施。%Shortage of effective potassium and toxicity of Fe2+ are important limited factors to rice yield in cold-waterlogged paddy field.Based on the field experiment,the effects of rice growth physiology,plant potassium iron nutrient accumulation and rice yield components were studied in cold-waterlogged paddy field under different potassium utilized in the paper.The results indicated that the content of chlorophyll a+b and photosynthetic ratio could respectively improve 10.53% ~ 22.67%、27.71% ~ 48.62% in booting stage under potassium fertilizer increasement,10.53%~22.67%、27.71 %~48.62% for root activity improved respectively in booting stage and mature stage.Meanwhile,rice yield could improve 4.93%~14.77%.Potassium fertilizer increased could not only promote the absorption and transportation of potassium,inhibit the iron accumulation of rice root,but only could reduce respectively 0.04~0.73、0.33 ~0.95 and 0.62 ~0.82 percentage point for the content of iron in tillering stage

  4. 水稻类病斑突变体spl31的遗传分析与基因定位%Genetic Analysis and Fine Mapping of a Lesion Mimic Mutant spl31 in Rice

    代高猛; 朱小燕; 李云峰; 凌英华; 赵芳明; 杨正林; 何光华

    2013-01-01

    A lesion mimic mutant temporarily designated as spl31 was discovered in the progeny of an excellent indica restorer line Jinhui 10 with seeds treated by ethyl methane sulfonate (EMS).The mutant phenotype was normal before the three leaf period but with yellow bad spots on leaves after the four leaf period.Along with the growth and development of the plant,the number of spots didn't show significant difference,whereas the lesion area gradually enlarged and developed with tawny margin.As the spl31 matured,lesion spots interconnected between each other becoming a continuous piece,resulting in leaves' death.The observation by transmission electronic microscope (TEM) demonstrated that most grana lamellae in spl31 's chroloplasts were irregularly stacked.Histochemical analysis revealed that deep blue stained cells presented discrete dietilution,illustrating that the lesion mechanism of spl31 may be spontaneously generated.The photosynthetic data showed that the mutation of spl31 had no effect on PSII.Furthermore,both 1000-grain weight and seed setting rate of the mutant decreased as compared with the wild type.Genetic analysis suggested that spl31 was controlled by a single nuclear recessive gene.Nipponbare was crossed with the spl31 and 621 mutational F2 recessive plants were used for gene mapping.And finally,Spl31 locus was mapped on chromosome 12 near the centromere between ID104 and ID11 with physical distance of 383 kb and co-segregated with ID105.%利用EMS诱变水稻籼型恢复系缙恢10号,从其后代中鉴定出一个类病斑突变体spl31,该突变体三叶期以前表型正常,四叶期后叶片陆续出现黄色斑点,随着植株的生长,面积逐渐扩大成边缘黄褐色的病斑,至成熟时病斑相互连接成片,导致叶片坏死.透射电镜结果显示突变体细胞的叶绿体基粒片层堆叠不规则.组织化学分析显示突变体细胞被染成深蓝色,呈离散状分布,说明spl31病斑是自发形成的.光合数据显示spl31

  5. Genetic Analysis and Gene Mapping of Early Senescence Leaf Mutant esl2 in Rice%水稻早衰突变体esl2的遗传分析及基因定位

    徐芳芳; 桑贤春; 任德勇; 唐彦强; 胡宏伟; 杨正林; 赵芳明; 何光华

    2012-01-01

    An early senescence leaf mutant temporarily designated as esl2 was discovered in the progeny of an excellent indica restorer line Jinhui 10 with seeds treated by ethyl methane sulfonate (EMS). The mutant kept normal at seedling stage and showed etiolated senescence leaves from booting sage to the maturity, especially at tip and margin of leaf blade. By contrast with the wild type, photosynthetic pigment contents decreased significantly at both booting stage and heading stage, superoxide dismutase (SOD) activity and soluble protein contents decreased significantly, while the activities of peroxidase (POD) and catalase (CAT), and contents of reactive oxygen species (ROS), malondialdehyde (MDA) and praline increased significantly at heading stage in the esl2 mutant. The assay of Transmission Electronic Microscope (TEM) observation was performed and demonstrated that the most cells appeared irregular and void with endolysis and disrupted organdies at senescence part of the mutational leaf, concomi-tantly, abnormal chloroplast appeared and showed dissolved membrane, indistinct grana, disorganized lamellar structure and incorrect thylakoid. Genetic analysis suggested that the mutational trait was controlled by one nuclear recessive gene. Xinong I A was crossed with the esl2 and 1 005 mutational F2 single plants were used for gene mapping. Finally, Esl2 locus was mapped between SSR marker RM17122 and swu4-13 on the chromosome 4 with physical distance of 244 kb. This result provides a foundation of Esl2 gene cloning by map-based strategy as well as its functional analysis.%利用EMS诱变水稻籼型恢复系缙恢10号,从其后代中鉴定出一个早衰突变体esl2,苗期正常,孕穗期开始叶尖和叶缘黄化衰老.与野生型相比,孕穗期和抽穗期光合色素含量均显著下降,抽穗期倒一叶的超氧化酶歧化酶(SOD)活性、可溶性蛋白(SP)含量降低,活性氧(ROS)、过氧化物酶(POD)、过氧化氢酶(CAT)、丙二醛(MDA)和脯氨

  6. Effects of Cd-spiking Treatment on Cd Accumulation, Subcellular Distribution and Content of Nonprotein Thiols in Rice%外加镉对水稻镉吸收、亚细胞分布及非蛋白巯基含量的影响

    史静; 潘根兴

    2015-01-01

    staple crops, rice (Oryza sativa L.) is the particular food crop with high Cd uptake and accumulation in grains. There had been much evidences of differences in Cd accumulation in plants and plant tolerance to between rice species and genotypes. Meanwhile, Cd tolerance and low Cd accumulation in grains may be used as a strategy for low Cd rice production. However, the mechanisms involved in Cd tolerance and grain accumulation has been not clearly demonstrated. Studying cadmium absorption characteristics under different rice varieties with Cd contaminated soil, the detoxification mechanism of PCs (mainly Non-protein thiol) and from micro level explore the distribution of cadmium subcellular. Its has huge significance to understand the resistance mechanism of Cd in different rice genotypes. In an effort to understand the biological process of Cd bioaccumulation, a pot experiments with subcelluar fractionation were carried out to investigate the subcelluar distribution of Cd in roots and leaves of rice. Two rice cultivars, Zhongzheyou-1, a high grain Cd accumulation cultivar, and J196, a low Cd accumulating cultivar, were grown in red soils. The experiment was conducted to study the effect of Cd-spiking treatment on Cd content, nonprotein thiols (NPT) production and its subcellular distribution in rice. The results showed that Cd stress had significant inhibitory effects on NPT overproduction. The Cd uptake of rice was affected by the Cd-spiking treatment and the genotypes. Furthermore, the Cd content was enhanced with increasing Cd supply, coinciding with the enhancement of NPT level in root. Compared the two varieties, when soil without Cd. The ratio of J196 aboveground Cd content/root Cd content is higher than Zhong-Zhe Optimal number 1;when the soil Cd content was 5 mg·kg-1, the amount of root A transform Cd to aboveground is far more than C, respectively 25.7% and 7.4%; but when the soil Cd content was 25 mg·kg-1, there was no significant difference between the two

  7. Trace Element Management in Rice

    Abin Sebastian

    2015-08-01

    Full Text Available Trace elements (TEs are vital for the operation of metabolic pathways that promote growth and structural integrity. Paddy soils are often prone to TE limitation due to intensive cultivation and irrigation practices. Apart from this, rice paddies are potentially contaminated with transition metals such as Cd, which are often referred to as toxic TEs. Deficiency of TEs in the soil not only delays plant growth but also causes exposure of plant roots to toxic TEs. Fine-tuning of nutrient cycling in the rice field is a practical solution to cope with TEs deficiency. Adjustment of soil physicochemical properties, biological process such as microbial activities, and fertilization helps to control TEs mobilization in soil. Modifications in root architecture, metal transporters activity, and physiological processes are also promising approaches to enhance TEs accumulation in grains. Through genetic manipulation, these modifications help to increase TE mining capacity of rice plants as well as transport and trafficking of TEs into the grains. The present review summarizes that regulation of TE mobilization in soil, and the genetic improvement of TE acquisition traits help to boost essential TE content in rice grain.

  8. Alpha-picolinic acid,a fungal toxin and mammal apoptosis-inducing agent,elicits hypersensitive-like response and enhances disease resistance in rice

    Hai Kuo ZHANG; Xin ZHANG; Bi Zeng MAO; Qun LI; Zu Hua HE

    2004-01-01

    Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.

  9. [Effects of applying nitrogen fertilizer and fertilizer additive on rice yield and rice plant nitrogen uptake, translocation, and utilization].

    Li, Wen-jun; Xia, Yong-qiu; Yang, Xiao-yun; Guo, Miao; Yan, Xiao-yuan

    2011-09-01

    A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P 0.05). The N translocation rate after anthesis and the N fertilizer use efficiency decreased with increasing N application rate. Applying fertilizer additive further improved the rice yield, accumulative absorbed N, N translocation rate after anthesis, and N fertilizer use efficiency, and this effect was more evident when the N application rate was equal to or greater than 200 kg x hm(-2). Relatively high rice yield and N use efficiency were achieved when applying 150 kg x hm(-2) of N fertilizer without the application of fertilizer additive.

  10. Genetic Analysis and Gene Mapping of a New Narrow-leaf Mutant in Rice (Oryza sativa L.)%一个新的水稻窄叶突变体的遗传分析和基因定位

    李娟; 李东宣; 甘树仙; 冯德党; 朱骞; 熊海波; 张小玲; 陈丽娟

    2011-01-01

    The exploration of new genes controlling flee leaf shape is an important foundation for flee functional genomies and plant architecture improvement. In the present study, a new narrow-leaf mutant MR11, which exhibits the characteristic phenotype of narrow leaves, short leaves and dwarf at whole growth stages, has been identified.In accordance with reduced leaf blade width, leaves of MRll contain a decreased number of longitudinal veins and narrow width between the small veins, the width of the reverse 2nd leaf in the mutant was less than 1/2 that of its wild type. Two populations, F2 and BC1F1 were used for genetic analysis, the result revealed that the phenotype was controlled by a pair of single recessive nuclear gene. The F2 population was used for mapping this gene by map-base cloning method, and result showed the gene is located between two simple sequence repeat (SSR) markers RM17486 and RM6629 on the long ann of chromosome number four, with genetic distances 0.3 cM and 2.8 cM,respectively. Sequence analysis showed that the phenotype of narrow leaves is not caused by the known gene NALl,this gene is a new narrow-leaf gene, although located at the same chromosome segment with NALl, that was tentatively designated as nall(t).%水稻叶片形态相关突变体是水稻功能基因组学研究和株型改良的重要材料.本研究以新的窄叶突变体MR11为研究材料,发现该突变体在整个生育期表现为窄叶、叶长变短和植株矮化.叶片组织结构观察发现由于叶脉数减少和叶脉问宽度减小,导致突变体倒二叶叶片宽度不及野牛型的1/2.F2和BC1F1两个群体分离结果表明该窄叶突变体表型受一对隐性核基因控制.选用F2群体采用图位克隆法进行基因定位,被定位在第4号染色体长臂上的SSR标记RM17486和RM6629之间,遗传距离分别为0.3 cM和2.8 cM.序列分析证明MR11窄叶性状不是由已克隆的NAL1引起,该基因虽与NAL1位于同一染色体区段,是一个

  11. Elicitor induced activation of the methylerythritol phosphate pathway toward phytoalexins biosynthesis in rice.

    Okada, Atsushi; Shimizu, Takafumi; Okada, Kazunori; Kuzuyama, Tomohisa; Koga, Jinichiro; Shibuya, Naoto; Nojiri, Hideaki; Yamane, Hisakazu

    2007-09-01

    Diterpenoid phytoalexins such as momilactones and phytocassanes are produced via geranylgeranyl diphosphate in suspension-cultured rice cells after treatment with a chitin elicitor. We have previously shown that the production of diterpene hydrocarbons leading to phytoalexins and the expression of related biosynthetic genes are activated in suspension-cultured rice cells upon elicitor treatment. To better understand the elicitor-induced activation of phytoalexin biosynthesis, we conducted microarray analysis using suspension-cultured rice cells collected at various times after treatment with chitin elicitor. Hierarchical cluster analysis revealed two types of early-induced expression (EIE-1, EIE-2) nodes and a late-induced expression (LIE) node that includes genes involved in phytoalexins biosynthesis. The LIE node contains genes that may be responsible for the methylerythritol phosphate (MEP) pathway, a plastidic biosynthetic pathway for isopentenyl diphosphate, an early precursor of phytoalexins. The elicitor-induced expression of these putative MEP pathway genes was confirmed by quantitative reverse-transcription PCR. 1-Deoxy-D: -xylulose 5-phosphate synthase (DXS), 1-deoxy-D: -xylulose 5-phosphate reductoisomerase (DXR), and 4-(cytidine 5'-diphospho)-2-C-methyl-D: -erythritol synthase (CMS), which catalyze the first three committed steps in the MEP pathway, were further shown to have enzymatic activities that complement the growth of E. coli mutants disrupted in the corresponding genes. Application of ketoclomazone and fosmidomycin, inhibitors of DXS and DXR, respectively, repressed the accumulation of diterpene-type phytoalexins in suspension cells treated with chitin elicitor. These results suggest that activation of the MEP pathway is required to supply sufficient terpenoid precursors for the production of phytoalexins in infected rice plants.

  12. Characterization and Gene Mapping of Rolled Leaf Mutant 28 (rl28) in Rice (Oryza sativa L.)%水稻卷叶突变体rl28的特性与基因定位

    冯萍; 邢亚迪; 刘松; 郭爽; 朱美丹; 娄启金; 桑贤春; 何光华; 王楠

    2015-01-01

    Leaves play a very important role in plant development for their function of photosynthesis. Moderate rolling leaves can facilitate the improvement of plant’s population structure and enhance light-use efficiency, which is very important in ideotype breeding. Therefore, the rolled leaf genes which regulate morphology in rice are important for exploring plant type and improving basic research in molecular biology. This study reported a new generolled leaf 28 (rl28), which was derived from EMS-treated restorer line Jinhui10. The mutational trait inherited steadily after several generations’ self-crossing. Compared with the wild-type, the leaves ofrl28 began to curl along the vasculan bundle in medial axis from jointing stage, leaf rolling index was significantly higher than that of the wild-type, and leaf angles were less than those of wild-type. Scanning electron microscopy and morpho-logical analysis showed stoma number per 10–5 m2 and stomatal conductance were significantly higher than those of the wild-type, transpiration rate was significantly higher than that of wild-type. Compared with the wild-type, midrib ofrl28 was much larger, and the number of the two adjacent vesicular cells decreased. Genetic analysis showed that the mutational trait was controlled by a single recessive nuclear gene.RL28 was finally mapped on chromosome 5 between SSR markers 5-43 and 5-34 with an interval of 90 kb. These results provide a foundation for cloning and function analysis ofRL28.%叶片是光合作用的主要器官,适度卷曲有利于改善群体光照,提高光能利用率,因此,发掘和研究叶片发育相关基因是改良株型和植物生长发育研究的重要基础工作。本研究报道了一个新的水稻稳定遗传卷叶突变体 rolled leaf 28(rl28),与野生型相比,rl28从拔节期起叶片开始沿中轴脉向内侧卷曲,叶片的卷曲度均极显著高于野生型,且叶夹角也不同程度小于野生型。扫描电

  13. Special rice in China

    2001-01-01

    Xianggu Rice: The rice originated from Jiangyong County, Hunan Province. Its characteristics were: even in grain shape, white in color, special fragrant in taste, and sticky in quality. Handongzao: It was from Wannian County, Jiangxi Province. The rice had big, fertile, and white grain, which was soft with fragrant smell, and it had high head rice rate. So, the local peasants liked to plant it. It was one of the "Tribute rice " in old time. Shizhu "Imperial Rice": The rice was also called "Fragrant Rice", was from Siyuan Village, Yuelai Town, Shizhu County, Sichuan Province. It was the treasure among the rices. The grain was bright in color. When it was cooked, the smell was fragrant. It was said that the rice was from "Han Dynasty", and has become the "Tribute Rice " since then. Blood Glutinous Rice: Originated from Changshu City, Jiangsu Province, the rice has been cultivated more than one hundred years. It had high nutrition value. Among the people, the Blood Glutinous Rice was often used as health food for lying-in women and patients. Qufu Fragrant Rice: Its characteristics were: clean, bright, and translucent in grain color, sticky in quality. It was suitable for cooking gruel and was also called "Fragrant Rice" in the local due to its strong fragrance. It was one of the "Tribute Rice" in old time. Taihu Lake Fragrant Japonica: The rice was from the Region of Taihu Lake, Jiangsu Province. The characteristics were: even and big in grain shape, soft in quality, white in color, fragrant in taste. The local people liked to plant and eat it.□ (To be continued) Translated by CHEN Wenhua, From "China Rice",No.1,1994

  14. Expression and characterization of rice putative PAUSED gene

    Chengguo Yao; Liangfa Ge; Wei Li; Botao Zhao; Chaoqun Li; Kangcheng Ruan; Hongxuan Lin; Youxin Jin

    2008-01-01

    In Arab idopsis, PA USED ( PSD ) encodes the ortholog of loslp/ exportin-t, which mediates the nuclear export of transfer RNA (tRNA) in yeast and mammals. However, in monocot plants such as rice, knowledge of the corresponding ortholog is limited, and its effects on growth development and productivity remain unknown. In this study, we verified a rice transfer-DNA insertional mutantpsd line and analyzed its phenotypes;the mutant displayed severe morphological defects including retarded development and low fertility compared with wild-type rice. Examining intronless tRNA-Tyr and intron-containing pre-tRNA-Ala expression levels in cytoplasmic and nuclear fraction with Northern blot analysis between wild -type and mutant leaf tissue suggested that rice PSD might be involved in tRNA export from the nucleus to the cytoplasm.Additionally, reverse transcription-polymerase chain reaction analysis revealed that PSD transcript was expressed throughout normal rice plant development, and subcellular localization assays showed that rice PSD protein was present in both the nucleus and cytoplasm. In summary, our data implied that the putative PSD gene might be indispensable for normal rice development and its function might be the same as that ofArabidopsis PSD.

  15. 脯氨酸代谢途径在调控水稻phyB突变体干旱胁迫耐性中的作用%Involvement of Proline Metabolic Pathway in Regulating Drought Tolerance in Rice phyB Mutant

    周晋军; 刘蓬; 尹静静; 谢先芝

    2014-01-01

    The expression levels of key genes involved in proline metabolic pathway were compared in rice wild type (WT)and phyB mutant.The results showed that dehydration treatment induced the expression of proline biosynthetic gene OsP5CS1 and OsOAT,but suppressed the expression of proline catabolic gene OsP5CDH.And the expression level of OsP5CS1 gene in phyB mutant was obviously higher than that in WT, which suggesting that phyB negatively regulated its expression.To explore the relation between high OsP5CS1 transcript level and stronger drought tolerance in phyB mutant,the OsP5CS1 transgenic tobacco was obtained. Water loss rate assays of detached leaves revealed that transgenic tobacco showed a slower water loss rate com-pared to non-transgenic tobacco.In addition,the leaf disk differentiation rate under high salinity of transgen-ic tobacco was higher than that of non -transgenic tobacco.These findings suggested that the regulation of phyB on proline metabolic pathway was one of the important factors contributing to stronger drought tolerance in phyB mutant.%本研究分析了水稻野生型和phyB突变体中脯氨酸代谢途径关键基因的表达水平。结果显示,干旱处理能够诱导脯氨酸生物合成相关基因OsP5CS1和OsOAT的表达,抑制脯氨酸生物降解基因OsP5CDH的表达。且phyB突变体中OsP5CS1基因的表达水平明显高于野生型,据此推测phyB负调控OsP5CS1基因的表达。为了分析OsP5CS1基因的高水平表达是否与phyB突变体较强的干旱胁迫耐性有关,本研究进一步培育了转OsP5CS1基因烟草。离体叶片失水速率结果表明,转基因烟草的失水速率小于野生型;盐胁迫条件下,转基因烟草的分化率明显高于野生型。综上所述,phyB对脯氨酸代谢途径的调控是phyB突变体具有较强干旱胁迫耐性的重要因素之一。

  16. Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

    Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E. (North Carolina State Univ., Raleigh (United States))

    1991-10-01

    The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  17. Mutants of Cercospora kikuchii Altered in Cercosporin Synthesis and Pathogenicity.

    Upchurch, R G; Walker, D C; Rollins, J A; Ehrenshaft, M; Daub, M E

    1991-10-01

    We have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  18. Effects of Nitrogen Fertilization and Genotype on Rice Grain Macronutrients and Micronutrients

    LIN Zhao-miao; NING Hui-feng; BI Jun-guo; QIAO Jiang-fang; LIU Zheng-hui; LI Gang-hua; WANG Qiang-sheng; WANG Shao-hua; DING Yan-feng

    2014-01-01

    High nitrogen (N) input features China’s intensive rice production system. To elucidate N and genotype effects on accumulation of macronutrients and micronutrients in grains of japonica rice, and to discuss its significance in rice production, a three-year field experiment involving six japonica rice varieties and seven N treatments were performed. Macronutrients (Ca, Mg, K, and Na) and micronutrients (Cu, Fe, Mn, and Zn) concentrations in brown and milled rice were measured using an atomic absorption spectrophotometer. For macronutrients, no consistently significant effect of N was detected in both brown and milled rice. For micronutrients, N showed significant effect, especially in lowering Zn accumulation in brown and milled rice. In addition, N tended to increase Fe concentration in milled rice. Genotype showed larger effect on distribution of minerals in milled rice than N. The high-yielding variety, Wuyunjing 7, accumulated larger proportion of Mg, K, and Zn in the milled rice as compared with the other five varieties, and could be of value for rice breeding programs aiming at high nutritional quality. The results demonstrated differences in response to N between macronutrients and micronutrients, and are of significance for coping with‘hidden hunger’ both in humans and crops through agronomical practices.

  19. 粳稻02428突变体重组自交系糙米功能成分含量及其与农艺性状的相关分析%Correlation Analysis of Agronomic Characters and Functional Activity Substants Contents in Recombinant Inbred Lines(RIL) of Japanica Mutant 02428 in Rice

    谢勇武; 杨树明; 曾亚文; 杨涛; 普晓英; 杜娟

    2011-01-01

    利用粳稻02428突变体的RIL群体336个F9家系,对糙米中总黄酮和生物碱等2种功能活性成分含量的变异及其与主要农艺性状的相关性进行分析.结果表明,①2种功能活性成分在F9家系间均有较大的变异,其中生物碱含量变异最大,总黄酮变异最小,变异系数分别为55.87%和22.67%.②剑叶宽与总黄酮含量(0.135**)、结实率与生物碱含量(0.130**)呈极显著相关;穗下节长与总黄酮含量(0.127*)、秕粒数与生物碱含量(-0.125*)呈显著相关.③剑叶宽、穗下节长与总黄酮含量、秕粒数与生物碱含量的相关关系主要是直接效应,直接通径系数分别为0.129,0.250和-0.298;结实率与生物碱含量的相关主要是通过株高、剑叶长宽、穗颈长、穗下节长、1~2节长、穗长、实粒数、秕粒数的间接作用,说明剑叶宽、穗下节长、秕粒数和结实率可作为高含量总黄酮、生物碱水稻品种选育的重要参考指标.%The correlation between functional activity substanls contents and main agronomic characters was analyzed using 336 RIL population (F9 ) derived from an Mutant 02428 of a set brown rice. The results showed that: (I) There were high variation among total flavones and alkaloid in brown rice for RIL. The variation coefficient of alkaloid content was the highest (55.87 % ) , whereas that of flavones content was the lowest (22.67 %). (ii)There were very significant correlation between flag leaf width and total flavones content (0. 135* * ) , seed setting rate and alkaloid content (0.130 * * ) , significant correlation between node length under spike and total flavones content (0. 127 * ) , blighted grains per panicle and alkaloid content ( -0.125 * ) ; (iii) Total flavones content was affected by flag leaf width and node length under spike directly, and alkaloid content was affected by blighted grains per panicle, and direct path coefficients was 0.129, 0.250 and -0.298, respectively. The

  20. Identification and Gene Mapping of Male Sterile Mutant gamyb5 in Rice%水稻雄性不育突变体gamyb5的鉴定与基因定位

    杨正福; 张迎信; 孙廉平; 张沛沛; 轩丹丹; 刘嶺; 胡霞; 李紫荷; 占小登

    2016-01-01

    在60Co-γ射线辐射诱变籼稻中恢8015的突变体库内发现了一个无花粉型雄性不育突变体gamyb5.gamyb5的株型、株高、分蘖数等农艺性状与野生型中恢8015无差异,而其花药细长且呈白色半透明状,花药中无花粉粒.花药半薄切片观察结果表明,gamyb5的小孢子母细胞减数分裂异常,没有形成正常的四分体和小孢子,并且绒毡层异常伸长,细胞程序性死亡延迟.对以gamyb5为母本,与野生型中恢8015和广亲和粳稻品种02428分别配制的杂交组合遗传分析表明,gamyb5突变性状受一个隐性核基因控制.利用gamyb5和02428杂交的F2定位群体,最终将突变基因精细定位于第1染色体长臂的ZF-29和ZF-31两个标记之间,物理距离约16.9 kb.对该区域内2个完整的开放阅读框测序分析发现,编码受赤霉素诱导的MYB转录因子基因LOC_Os01g0812000的第2外显子存在8个碱基的缺失,导致翻译提前终止.qRT-PCR检测到影响花药发育的调控因子UDT1、TDR、CYP703A3和CYP704B2的表达量在突变体中比野生型中极显著降低.进一步证明GAMYB在花药减数分裂和绒毡层细胞程序性死亡过程中起关键作用.%The gamyb5 ,a pollen-free male sterile mutant was identified from the mutant library of 60 Co-γ-treated indica cultivar Zhonghui 8015.There was no significant difference in agronomic traits such as plant type,plant height and tiller number between gamyb5 and the wild-type.But gamyb5 exhibited slender and white anthers without mature pollen grains.Observation results of anther cross-sections exhibited that the microspore mother cells failed to form functional tetrads and microspores in gamyb5 .Moreover,tapetal cells of gamyb5 abnormally enlarged and the tapetum programmed cell death (PCD)was delayed.gamyb5 ,as the pollen acceptor,was crossed with the wild type Zhonghui 8015 and a japonica cultivar 02428,respectively.Genetic analysis of all hybridization populations indicated that

  1. Deciphering Starch Quality of Rice Kernels Using Metabolite Profiling and Pedigree Network Analysis

    Miyako Kusano; Atsushi Fukushima; Naoko Fujita; Yozo Okazaki; Makoto Kobayashi; Naoko Fujita Oitome; Kaworu Ebana; Kazuki Saito

    2012-01-01

    The physiological properties of rice grains are immediately obvious to consumers.High-coverage metabolomic characterization of the rice diversity research set predicted a negative correlation between fatty acid and lipid levels and amylose/total starch ratio (amylose ratio),but the reason for this is unclear.To obtain new insight into the relationships among the visual phenotypes of rice kernels,starch granule structures,amylose ratios,and metabolite changes,we investigated the metabolite changes of five Japonica cultivars with various amylose ratios and two knockout mutants (e1,a Starch synthase Ⅲa (SSⅢa)-deficient mutant and the SSⅢa/starch branching enzyme (BE) double-knockout mutant 4019) by using mass spectrometry-based metabolomics techniques.Scanning electron microscopy clearly showed that the two mutants had unusual starch granule structures.The metabolomic compositions of two cultivars with high amylose ratios (Hoshiyutaka and Yumetoiro) exhibited similar patterns,while that of the double-knockout mutant,which has an extremely high amylose ratio,differed.Rice pedigree network analysis of the cultivars and the mutants provided insight into the association between metabolic-trait properties and their underlying genetic basis in rice breeding in Japan.Multidimensional scaling analysis revealed that the Hoshiyutaka and Yumetoiro cultivars were Indica-like,yet they are classified as Japonica subpopulations.Exploring metabolomic traits is a powerful way to follow rice genetic traces and breeding history.

  2. bHLH142 regulates various metabolic pathway-related genes to affect pollen development and anther dehiscence in rice

    Ranjan, Rajeev; Khurana, Reema; Malik, Naveen; Badoni, Saurabh; Parida, Swarup K.; Kapoor, Sanjay; Tyagi, Akhilesh K.

    2017-01-01

    Apposite development of anther and its dehiscence are important for the reproductive success of the flowering plants. Recently, bHLH142, a bHLH transcription factor encoding gene of rice has been found to show anther-specific expression and mutant analyses suggest its functions in regulating tapetum differentiation and degeneration during anther development. However, our study on protein level expression and gain-of-function phenotype revealed novel aspects of its regulation and function during anther development. Temporally dissimilar pattern of bHLH142 transcript and polypeptide accumulation suggested regulation of its expression beyond transcriptional level. Overexpression of bHLH142 in transgenic rice resulted in indehiscent anthers and aborted pollen grains. Defects in septum and stomium rupture caused anther indehiscence while pollen abortion phenotype attributed to abnormal degeneration of the tapetum. Furthermore, RNA-Seq-based transcriptome analysis of tetrad and mature pollen stage anthers of wild type and bHLH142OEplants suggested that it might regulate carbohydrate and lipid metabolism, cell wall modification, reactive oxygen species (ROS) homeostasis and cell death-related genes during rice anther development. Thus, bHLH142 is an anther-specific gene whose expression is regulated at transcriptional and post-transcriptional/translational levels. It plays a role in pollen maturation and anther dehiscence by regulating expression of various metabolic pathways-related genes. PMID:28262713

  3. Zinc up-regulated the expression of the rice metallonthionein gene family and enhanced the zinc tolerance of yeast cells

    2007-01-01

    Northern blot and functional complementation assay were employed to analyze the effects of zinc on expression of ten rice metallothionein genes (OsMT-Is) in rice seedlings and the growth of yeast cells transformed with OsMT-Is. Northern blot revealed that in shoots of the rice seedlings treated with different Zn2+ concentrations, expression of most members of OsMT-I family was increased, except the type 4 OsMT-Is (OsMT-I-4a, 4b and 4c). In roots, Zn2+ significantly increased the transcription of OsMT-I-1b and OsMT-I-2c, but reduced the trascription of OsMT-I-1a and OsMT-I-3a. When these ten cDNAs were heterologously expressed in zinc sensitive yeast mutant, all transgenic yeasts showed increased tolerance to Zn2+, and zinc accumulation in these yeast cells also increased.These indicated that OsMT-I family members might respond to extra Zn2+, and they could enhance Zn2+ tolerance of cells by direct binding Zn2+.

  4. 水稻显性窄叶突变体Dnal1的鉴定与基因定位%Identification and Gene Mapping of a Dominant Narrow Leaf MutantDnal1 in Rice (Oryza sativa)

    桑贤春; 林婷婷; 何沛龙; 王晓雯; 廖红香; 张孝波; 马玲; 何光华

    2014-01-01

    极显著下降,导致Dnal1的千粒重仅为野生型的73.18%,极显著下降。低密度种植条件下,Dnal1的理论产量显著低于野生型;高密度种植条件下,Dnal1的理论产量则显著高于野生型,较高的结实率和单株有效穗是Dnal1产量提高的主要原因。西农1A/Dnal1与Dnal1/中花11杂交组合的F1群体,剑叶的叶片宽度分别为0.99 cm和0.94 cm,与Dnal1的0.96 cm相比,无显著差异;F2群体中出现窄叶植株和宽叶植株两种类型,窄叶和宽叶单株出现的频率呈双峰分布,且窄叶和宽叶的分离比符合3﹕1,表明Dnal1的窄叶性状受1个显性主效基因调控。利用分子标记最终将DNAL1定位在第2染色体上,位于SSR标记RM13646和RM1307之间,物理距离为391 kb。【结论】Dnal1是一个EMS诱变获得的显性窄叶水稻突变体,基因定位在第2染色体391 kb的物理范围内,在高密度种植条件下具有增产潜力。%Objective Leaf blade is the main location of photosynthesis in high plants. A moderate narrowing could enhance crop quality and yield by fascinating the utilization of solar energy and has been paid wide attentions in crop breeding. A novel dominant narrower leaf mutant has been identified and the results provided a foundation in the research of leaf morphological formation and plant type breeding inOryza sativa.[Method]A narrow leaf mutant (Dnal1) was discovered from the progeny of indica restorer line Jinhui10 with seeds treated by ethyl methanesulfonate and the trait of narrow leaf has inherited steadily after seven generations’ self-fertility. The flag, second and third leaf blades were utilized for detecting leaf widths and rolled indexes at the blooming stage, meanwhile, the middle position of flag leaf was used for paraffin section. At the filling stage, the characteristics of chloroplast pigment, photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) were measured. TheDnal1 was crossed withindica line

  5. 水稻株型突变体rad-1和rad-2的鉴定与功能基因克隆%Identification and Map-based Cloning ofrad-1 andrad-2, Two Rice Architec-ture Determinant Mutants

    牛静; 陈赛华; 赵婕妤; 曾召琼; 蔡茂红; 周亮; 刘喜; 江玲; 万建民

    2015-01-01

    株型是决定水稻等作物产量的核心因素之一,是品种选育的重要指标。本研究从粳稻品种Asominori的辐射诱变中分离出2个稳定的株型突变体, rad-1和rad-2,它们均表现出苗期弯曲生长、成熟期株高矮化、粒长变短、千粒重降低和产量下降等特征。等位性测验结合连锁分析证实rad-1和rad-2等位,且位于水稻第7染色体上约230 kb的范围内。对定位区段的序列分析后确定OsFH5为候选基因,该基因呈现组成型表达,编码水稻II型成蛋白。突变体rad-1在OsFH5基因第2个外显子上缺失8个碱基,导致移码;而rad-2则在第14内含子上发生单碱基的变异,发生异常剪切。两类突变最终均导致OsFH5基因翻译提前终止,产生截短的蛋白。相比野生型, rad-1和rad-2在幼苗中OsFH5基因的表达下调。细胞学研究表明, OsFH5基因的功能缺失会导致幼苗叶鞘细胞大小不均,呈现不规则生长,在成熟的颖壳中细胞显著变短。对生长素响应的 ARF因子进行表达量检测发现, rad-2中一系列 ARF成员表达均显著下调,推测OsFH5极有可能影响了植株对生长素的响应。%Plant architecture is a key element of crop yield and also taken as a criterion in breeding. In this study, two rice archi-tecture determinant mutants,rad-1 andrad-2 were selected from Gamma-radiation induced mutants of rice cultivar Asominori. Each of them shows winding seedlings, dwarf plants and thereby decreased yield. It has been estimated thatrad-1 andrad-2 are allelic to each other by allelism test and linkage analysis. After map-based cloning, the responsible gene for the mutations was restricted within a 230 kb region in chromosome 7. Sequence analysis revealed thatOsFH5 gene, encoding a forming-like protein altered both inrad-1 andrad-2. An 8-bp deletion in exon 2 inrad-1 and a single nucleotide change in intron 14 inrad-2 made frame-shift reading and produced truncated proteins.OsFH5 gene

  6. The World of Rice

    VALERIE SARTOR

    2010-01-01

    @@ Pilafs, risottos, soups, snacks, paellas,stuffing, vinegars, wines and desserts-rice is used all over the world in myriad ways as food and drink.Although rice is one of the world's most ancient foods and it is impossible to know exactly where and when cultivation of this marvelous grain began, China is popularly acknowledged as the homeland of rice. Chinese people have many legends about rice. Some describe a benevolent goddess in silk robes whose gown accidentally picked up stray rice grains, which she dropped from the heavens to humans below. It's also said that Shennong, the Divine Farmer in Chinese myth, sowed the first rice on earth.

  7. 有色金属矿区农田土壤-水稻镉积累状况及其响应关系研究%Cadmium Accumulation in Paddy Soil-rice System and Their Response Relationship in Non-ferrous Metal Mine Area

    季梦兰; 严俊; 林华; 张学洪; 李海翔

    2016-01-01

    accumulation characteristics and responses of heavy metals in soil-rice system would be a practical significance for guiding practice production.%位于西江上游的河池地区被誉为中国的“有色金属之乡”,重金属产业经过多年选矿开矿的工业化发展使得当地生态环境受到严重的重金属污染。为评价广西西江流域中上游主要地区矿业活动对土壤和糙米质量安全的影响,采集研究区域内水稻及其对应土壤样本进行分析评价。调查发现,参照《食用农产品产地环境质量评价标准》(HJ332—2006),当pH7.5时,土壤Cd含量超标率分别达到90.63%、96.97%、98.36%;参照《食品中污染物限量标准》(GB2762—2012),糙米Cd含量的超标率为19.34%。单因子污染评价表明,超过50%的调查样点土壤Cd处于重度污染,仅有10%左右调查样点的土壤Cd属于清洁等级,且上游地区土壤-水稻系统Cd污染较为严重。分别建立了水稻糙米Cd含量、糙米Cd 生物富集系数与土壤有效态 Cd 含量、土壤 pH 值以及土壤有机质含量的定量关系,模型拟合度均高于50%。预测糙米Cd 含量拟合度较好的模型为多元非线性回归模型,预测糙米 Cd 生物富集系数拟合度较好的为多元线性回归模型。多元回归模型的回代检验和残差分析表明,计算值与实测值的相关性较好,残差值较小且均匀分布,在一定程度上可以用来预测水稻糙米Cd的积累情况。

  8. 水分管理对硫铁镉在水稻根区变化规律及其在水稻中积累的影响%Accumulation of S, Fe and Cd in Rhizosphere of Rice and Their Uptake in Rice with Different Water Managements

    张雪霞; 张晓霞; 郑煜基; 王荣萍; 陈能场; 卢普相

    2013-01-01

    选取了酸性矿山废水污灌区重金属污染水稻土,通过盆栽试验研究了不同水分管理条件(60%最大田间持水量,80%最大田间持水量,最大田间持水量,前期淹水+抽穗扬花期烤田,全生育期淹水)下水稻根际土壤及其不同器官(稻根、茎叶和籽粒)中硫、Fe和Cd的含量变化.结果表明,随着土壤水分含量的增加,在分蘖期根际土壤中Cd的含量略有升高,在成熟期对水稻根际土壤中Fe和Cd含量的影响不大;水稻不同器官对铁的吸收逐渐增加,对Cd的吸收则逐渐减少,两者呈明显的负相关关系;但抽穗扬花期烤田对水稻各器官对Fe的吸收影响不大,却明显增加了各器官中Cd的含量.除旱作处理外,不同水分管理方式下,土壤中全硫和有效硫含量随着土壤水分含量增加逐渐减少,抽穗扬花期烤田能明显增加根际土壤中总硫和有效硫含量,水稻对Cd的吸收与根际硫含量增加存在协同关系.上述结果证实,水稻对Cd的吸收不仅与Fe吸收有关,土壤中硫的充分供给能显著增加Cd在水稻中的积累.%The interactions between the concentrations of sulfur,iron and cadmium in the rhizosphere and their uptakes in rice (Oryza sativa L.) were studied using paddy soil which was contaminated by acid mine drainage under five water-management treatments of 60%,80%,100% field moisture capacity (FMC),flooded throughout the entire rice growth period and flooded followed by keeping 80% FMC after heading-flowering period.The water managements had no significant influence on the Fe and Cd concentrations in rhizosphere soil in maturity stage,although the concentration of Cd slightly increased with the increase of soil moisture in the tillering stage.However,the uptake of Fe and Cd in rice was obviously related to water managements.The increase of soil moisture enhanced the uptake of Fe,but decreased the uptake of Cd in different organs of rice (roots,stems and leaves

  9. Effects of alginate-derived oligosaccharides synergistic urea on the photosynthetic characteristics and accumulation of carbon metabolites in rice%海藻寡糖增效尿素对水稻光合特性及碳代谢产物积累的影响

    张运红; 孙克刚; 杜君; 和爱玲; 张起义

    2016-01-01

    采用盆栽试验,研究了海藻寡糖增效尿素对水稻光合特性、碳代谢关键酶活性及相关产物积累的影响。结果表明,和普通尿素相比,海藻寡糖增效尿素处理的水稻净光合速率( Pn )、气孔导度( Gs )、胞间CO2浓度(Ci)和水分利用效率(WUE)有所增加,气孔限制值(Ls)有所降低,叶绿素含量和核酮糖-1,5-二磷酸羧化加氧酶(Rubisco)活性显著提高。拔节期、齐穗期和成熟期叶中和籽粒中蔗糖磷酸合成酶(SPS)、蔗糖合成酶( SUS)和腺苷二磷酸葡萄糖焦磷酸化酶( ADPase)活性显著增强,从而促进籽粒中蔗糖和淀粉积累;地上部和地下部生物量在4个生育期也均显著增加,籽粒产量显著提高,其中较对照增加9.32%,较普通尿素处理增加3.94%。%Pot experiments were used to study the effects of alginate-derived oligosaccharide ( ADO) synergistic urea on photo-synthetic characteristics, key enzymes activities and carbon metabolites accumulation of rice ( Oryza. Sativa L. ) . The results showed that net photosynthetic rate ( Pn ) , stomatal conductance ( Gs ) , intercellular CO2 concentration ( Ci ) and water use efficiency ( WUE) of rice under ADO synergistic urea treatment were increased, and stomatal limitation value ( Ls ) was de-creased, compared with ordinary urea. Chlorophyll content and ribulose-1, 5-bisphosphate-caboxylase ( Rubisco) activity were also significantly raised. At booting, full heading and maturing stages, sucrose phosphate synthase ( SPS) , sucrose syn-thase (SUS) and ADP-glucose pyrophosphorylase (ADPase) activity in leaves or grain of rice were significantly enhanced, thus contributing to the accumulation of sucrose and starch in grain. Aboveground and belowground biomass were also signifi-cantly increased at all the four growth stages. Rice yield of ADO synergistic urea treatment was significantly raised by 9. 32%compared with the control, and was higher than that of

  10. Special rice in China

    2001-01-01

    @@Mingshui Rice: It originated from Zhangqiu County, Shandong Province. The characteristics of Mingshui Rice were: absorbing more water, swelling up greatly after being soaked, and being sticky and smelling fragrant after cooked.

  11. Screening of Toxin Mutant of Dickeya zeae and Its Biological Characters

    Jingyi ZHANG; Yutao WANG; Yanchang LI; Qiongguang LIU

    2013-01-01

    [Objective] This study aimed to screen toxin mutant of Dickeya zeae (Er-winia chrysanthemi pv. zeae) and investigate its biological characters. [Method] We obtained a toxin mutant strain D. zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain. [Result] There was no significant difference in pectin lyase, protease, cellulase and the production of extracellular polysaccharide and lipopolysaccharide, but significant difference in toxin biological activities and vir-ulence. Ech7-3-42 mutant did not produce toxin, as wel as the loss of virulence on rice and HR on tobacco, but did not lose the ability to soft rot on potato. Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk, but it could not cause rice foot rot. Dickeya zeae (wild and mutant strain) could be detected by PCR in the root neck and below the 1-2 cm long stem area, but could not be detected in the leaves. [Conclusion] We believed that toxin may be one of the important factors for D. zeae virulence on rice.

  12. Phenolic Phytoalexins in Rice: Biological Functions and Biosynthesis

    Man-Ho Cho

    2015-12-01

    Full Text Available Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the only known phenolic phytoalexin in rice. However, recent studies have shown that phenylamides are involved in defense against pathogen attacks in rice. Phenylamides are amine-conjugated phenolic acids that are induced by pathogen infections and abiotic stresses including ultra violet (UV radiation in rice. Stress-induced phenylamides, such as N-trans-cinnamoyltryptamine, N-p-coumaroylserotonin and N-cinnamoyltyramine, have been reported to possess antimicrobial activities against rice bacterial and fungal pathogens, an indication of their direct inhibitory roles against invading pathogens. This finding suggests that phenylamides act as phytoalexins in rice and belong to phenolic phytoalexins along with sakuranetin. Phenylamides also have been implicated in cell wall reinforcement for disease resistance and allelopathy of rice. Synthesis of phenolic phytoalexins is stimulated by phytopathogen attacks and abiotic challenges including UV radiation. Accumulating evidence has demonstrated that biosynthetic pathways including the shikimate, phenylpropanoid and arylmonoamine pathways are coordinately activated for phenolic phytoalexin synthesis, and related genes are induced by biotic and abiotic stresses in rice.

  13. Rice Price under Pressure

    Liu Xinwen

    2008-01-01

    @@ Early in April, the FOB (Free on Board) value of rice exported from Bangkok, Thailand, the biggest rice exporter of the world, surged to a new high of US$730per ton, representing an increase of 70 percent in recent years, and setting a new record over the past 34 years of Thailand rice exports.

  14. Rice peasants and rice research in Colombia

    Spijkers, P.A.N.M.

    1983-01-01

    Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp i

  15. Rice (Oryza hemoglobins [v2; ref status: indexed, http://f1000r.es/4vp

    Raúl Arredondo-Peter

    2014-12-01

    Full Text Available Hemoglobins (Hbs corresponding to non-symbiotic (nsHb and truncated (tHb Hbs have been identified in rice (Oryza. This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O2-transport, O2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs.

  16. Special rice in China

    2001-01-01

    Wushan Rice: It grew in hilly land around Wu Mountain in Wang City, Hunan Province. Its grain is bright and transparent, and the cooked rice is soft, sticky, fragrant, and sweet in taste. It was a "Tribute Rice" in old time. Indian Indica: Growing in Wuchang City, Hubei Province, it was also called" Red Flower Rice" . It was characterized by its thin pericarp and soft, sticky, and oily quality. Its taste was delicious. Fragrant Rice 1: It was from Xinxiang and Hui counties, Henan Province. Its characteristics were: long-round in grain shape, white in color, soft and sticky in quality, and agreeable to the taste. It was usually used as a gift in the local. Baiyutang Rice: It originated from Gaozhuang Village, Beijing suburban district. It had good quality due to the irrigation of the spring water. The rice had even grain shape, white color, hard enough quality to be cooked, fragrant and sweet taste. It was one of the "Tribute Rice" in old time. Tian′e Indica Rice: Xianning and Wuchang counties, Hubei Province were its growing area. It also called "Double Grain" because of its big grain. The hull was red, while the grain was white. When cooked, it needed more water than normal rice, and the rice was agreeable to the taste. Baiyan Rice: It originated from Jishou County, Hunan Province. The grain was even in shape, white in color, and sticky in quality. The rice was easy to be cooked and was fragrant and sweet in taste. It was also a " Tribute Rice" in old time. □ (To be continued) Translated by CHEN Wenhua, From "China Rice", No. 1, 1994

  17. DEP and AFO regulate reproductive habit in rice.

    Kejian Wang

    2010-01-01

    Full Text Available Sexual reproduction is essential for the life cycle of most angiosperms. However, pseudovivipary is an important reproductive strategy in some grasses. In this mode of reproduction, asexual propagules are produced in place of sexual reproductive structures. However, the molecular mechanism of pseudovivipary still remains a mystery. In this work, we found three naturally occurring mutants in rice, namely, phoenix (pho, degenerative palea (dep, and abnormal floral organs (afo. Genetic analysis of them indicated that the stable pseudovivipary mutant pho was a double mutant containing both a Mendelian mutation in DEP and a non-Mendelian mutation in AFO. Further map-based cloning and microarray analysis revealed that dep mutant was caused by a genetic alteration in OsMADS15 while afo was caused by an epigenetic mutation in OsMADS1. Thus, OsMADS1 and OsMADS15 are both required to ensure sexual reproduction in rice and mutations of them lead to the switch of reproductive habit from sexual to asexual in rice. For the first time, our results reveal two regulators for sexual and asexual reproduction modes in flowering plants. In addition, our findings also make it possible to manipulate the reproductive strategy of plants, at least in rice.

  18. Cyclic electron flow around photosystem I via chloroplast NAD(P)H dehydrogenase (NDH) complex performs a significant physiological role during photosynthesis and plant growth at low temperature in rice.

    Yamori, Wataru; Sakata, Naoki; Suzuki, Yuji; Shikanai, Toshiharu; Makino, Amane

    2011-12-01

    The role of NAD(P)H dehydrogenase (NDH)-dependent cyclic electron flow around photosystem I in photosynthetic regulation and plant growth at several temperatures was examined in rice (Oryza sativa) that is defective in CHLORORESPIRATORY REDUCTION 6 (CRR6), which is required for accumulation of sub-complex A of the chloroplast NDH complex (crr6). NdhK was not detected by Western blot analysis in crr6 mutants, resulting in lack of a transient post-illumination increase in chlorophyll fluorescence, and confirming that crr6 mutants lack NDH activity. When plants were grown at 28 or 35°C, all examined photosynthetic parameters, including the CO(2) assimilation rate and the electron transport rate around photosystems I and II, at each growth temperature at light intensities above growth light (i.e. 800 μmol photons m(-2) sec(-1)), were similar between crr6 mutants and control plants. However, when plants were grown at 20°C, all the examined photosynthetic parameters were significantly lower in crr6 mutants than control plants, and this effect on photosynthesis caused a corresponding reduction in plant biomass. The F(v)/F(m) ratio was only slightly lower in crr6 mutants than in control plants after short-term strong light treatment at 20°C. However, after long-term acclimation to the low temperature, impairment of cyclic electron flow suppressed non-photochemical quenching and promoted reduction of the plastoquinone pool in crr6 mutants. Taken together, our experiments show that NDH-dependent cyclic electron flow plays a significant physiological role in rice during photosynthesis and plant growth at low temperature.

  19. Nitric oxide ameliorates zinc oxide nanoparticles-induced phytotoxicity in rice seedlings.

    Chen, Juan; Liu, Xiang; Wang, Chao; Yin, Shan-Shan; Li, Xiu-Ling; Hu, Wen-Jun; Simon, Martin; Shen, Zhi-Jun; Xiao, Qiang; Chu, Cheng-Cai; Peng, Xin-Xiang; Zheng, Hai-Lei

    2015-10-30

    Nitric oxide (NO) has been found to function in enhancing plant tolerance to various environmental stresses. However, role of NO in relieving zinc oxide nanoparticles (ZnO NPs)-induced phytotoxicity remains unknown. Here, sodium nitroprusside (SNP, a NO donor) was used to investigate the possible roles and the regulatory mechanisms of NO in counteracting ZnO NPs toxicity in rice seedlings. Our results showed that 10 μM SNP significantly inhibited the appearance of ZnO NP toxicity symptoms. SNP addition significantly reduced Zn accumulation, reactive oxygen species production and lipid peroxidation caused by ZnO NPs. The protective role of SNP in reducing ZnO NPs-induced oxidative damage is closely related to NO-mediated antioxidant system. A decrease in superoxide dismutase activity, as well as an increase in reduced glutathione content and peroxidase, catalase and ascorbate peroxidase activity was observed under SNP and ZnO NPs combined treatments, compared to ZnO NPs treatment alone. The relative transcript abundance of corresponding antioxidant genes exhibited a similar change. The role of NO in enhancing ZnO NPs tolerance was further confirmed by genetic analysis using a NO excess mutant (noe1) and an OsNOA1-silenced plant (noa1) of rice. Together, this study provides the first evidence indicating that NO functions in ameliorating ZnO NPs-induced phytotoxicity.

  20. Special rice in China

    2000-01-01

    @@Shanxi black rice It was originally from Yang County, Hanzhong Region.This rice was a world-famous rice variety developed in 140 BC. It had pitch-black surface with the protein and oil contents being 6.8% and 20% higher than that of common rice, respectively. It had 15 kinds of amino acids and many kinds of vitamins. It was praised as" Black pearl" and "The king of the world riee".DongnianThe other names for Dongnian were "Yellow rice" and "Oil rice". It was grown in E City and Huangmei County,Hubei Province. It was characterized by its long-slim shape, milky yellow in color, oily, solid, and sticky quality, fragrant smell, and easiness for digestion.Guizhou black pearl rice

  1. Proteomics of Rice Grain under High Temperature Stress

    Toshiaki eMitsui

    2013-03-01

    Full Text Available Recent proteomic analyses revealed dynamic changes of metabolisms during rice grain development. Interestingly, proteins involved in glycolysis, citric acid cycle, lipid metabolism, and proteolysis were accumulated at higher levels in mature grain than those of developing stages. High temperature stress in rice ripening period causes damaged (chalky grains which have loosely packed round shape starch granules. The high temperature stress response on protein expression is complicated, and the molecular mechanism of the chalking of grain is obscure yet. Here, the current state on the proteomics research of rice grain grown under high temperature stress is briefly overviewed.

  2. 秸秆覆盖还田对稻麦轮作体系中土壤及作物甲基汞累积的影响%Effects of straw amendment on methylmercury accumulation in soil and crop plants under wheat-rice rotation

    陈宗娅; 王永杰; 舒瑞; 付芳婧; 吴永贵

    2016-01-01

    There is growing concern about methylmercury(MeHg)accumulation in crop plants in Hg-contaminated areas. To investigate the possible influences of straw amendment on soil methylmercury levels and its accumulation in crop plants, mercury-contaminated paddy soil was collected from Wanshan mercury mine area and amended with 1%(W/W)crop straw(wheat or rice)in a wheat-rice rotation system. At different stages(e.g., seedling, tillering, jointing, flowering and harvesting)of plant growth, the soil and plant samples were collected and an-alyzed for MeHg. The results show that straw amendment could lead to a substantial increases in MeHg levels in both soils and plants. Soil MeHg increased by 127.1%under wheat-straw amendment and 25.1%under rice-straw amendment, respectively. This was possibly due to the different planting conditions. Correspondingly, MeHg levels in root, aboveground part and grain of wheat increased by 124.6%, 79.2%and 169%, respectively, compared to the control. Similarly, MeHg levels in root, aboveground part and grain of rice increased by 40.1%, 61.7% and 25.9%, respectively. Overall, there is a positive relationship between the crop plant MeHg levels and soil MeHg levels under wheat-rice rotation, indicating that straw amendment could increase soil MeHg levels and subsequently the MeHg accumulation in crops,which could enhance the potential risk of human exposure to MeHg in mercury-contaminated areas. These results suggest that it should be cautious when promoting straw amendment in mercury-contaminated areas.%以贵州万山汞矿区的汞污染稻田土为研究对象,采用盆栽模拟探究了小麦-水稻轮作情况下秸秆覆盖还田对土壤及小麦与水稻在重要生育期(出苗期、分蘖期、拔节期、扬花-灌浆期、乳熟-收获期)甲基汞累积的影响。结果表明:秸秆还田能提高土壤中甲基汞含量,且不同作物秸秆还田对土壤甲基汞及作物甲基汞的影响存在显著差别,其中,

  3. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    Maria Lígia de Souza Silva; Godofredo Cesar Vitti; Anderson Ricardo Trevizam

    2014-01-01

    Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different re...

  4. Protein repair L-isoaspartyl methyltransferase 1 (PIMT1) in rice improves seed longevity by preserving embryo vigor and viability.

    Wei, Yidong; Xu, Huibin; Diao, Lirong; Zhu, Yongsheng; Xie, Hongguang; Cai, Qiuhua; Wu, Fangxi; Wang, Zonghua; Zhang, Jianfu; Xie, Huaan

    2015-11-01

    Damaged proteins containing abnormal isoaspartyl (isoAsp) accumulate as seeds age and the abnormality is thought to undermine seed vigor. Protein-L-isoaspartyl methyltransferase (PIMT) is involved in isoAsp-containing protein repair. Two PIMT genes from rice (Oryza sativa L.), designated as OsPIMT1 and OsPIMT2, were isolated and investigated for their roles. The results indicated that OsPIMT2 was mainly present in green tissues, but OsPIMT1 largely accumulated in embryos. Confocal visualization of the transient expression of OsPIMTs showed that OsPIMT2 was localized in the chloroplast and nucleus, whereas OsPIMT1 was predominately found in the cytosol. Artificial aging results highlighted the sensitivity of the seeds of OsPIMT1 mutant line when subjected to accelerated aging. Overexpression of OsPIMT1 in transgenic seeds reduced the accumulation of isoAsp-containing protein in embryos, and increased embryo viability. The germination percentage of transgenic seeds overexpressing OsPIMT1 increased 9-15% compared to the WT seeds after 21-day of artificial aging, whereas seeds from the OsPIMT1 RNAi lines overaccumulated isoAsp in embryos and experienced rapid loss of seed germinability. Taken together, these data strongly indicated that OsPIMT1-related seed longevity improvement is probably due to the repair of detrimental isoAsp-containing proteins that over accumulate in embryos when subjected to accelerated aging.

  5. Nutritional constituents and health benefits of wild rice (Zizania spp.).

    Surendiran, Gangadaran; Alsaif, Maha; Kapourchali, Fatemeh Ramezani; Moghadasian, Mohammed H

    2014-04-01

    Wild rice (Zizania spp.) seems to have originated in North America and then dispersed into Eastern Asia and other parts of the world. Nutritional analysis shows that wild rice is rich in minerals, vitamins, protein, starch, dietary fiber, and various antioxidant phytochemicals, while it is low in fat. Wild rice has been recognized as a whole grain by the US Food and Drug Administration; in the North American marketplace it is currently sold as and considered to be a health-promoting food. Recent scientific studies have revealed antioxidant and lipid-lowering properties of wild rice, while others have documented cardiovascular benefits associated with the long-term consumption of wild rice in experimental settings. The present review article summarizes various features of wild rice and its cultivation, including its plantation, harvest, nutritional composition, and biological properties. While evidence for the cardiovascular benefits of wild rice consumption is accumulating, additional studies are warranted to determine the clinical benefits of regular consumption of wild rice.

  6. Conserved Functions of Arabidopsis and Rice CC-Type Glutaredoxins in Flower Development and Pathogen Response

    Zhen Wang; Shuping Xing; Rainer P. Birkenbihl; Sabine Zachgo

    2009-01-01

    Glutaredoxins (GRXs) are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we iso-lated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxy1 floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Ara-bidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop-ment and pathogen defence.

  7. Defective active silicon uptake affects some components of rice resistance to brown spot.

    Dallagnol, Leandro J; Rodrigues, Fabrício A; Mielli, Mateus V B; Ma, Jian F; Datnoff, Lawrence E

    2009-01-01

    Rice is known to accumulate high amounts of silicon (Si) in plant tissue, which helps to decrease the intensity of many economically important rice diseases. Among these diseases, brown spot, caused by the fungus Bipolaris oryzae, is one of the most devastating because it negatively affects yield and grain quality. This study aimed to evaluate the importance of active root Si uptake in rice for controlling brown spot development. Some components of host resistance were evaluated in a rice mutant, low silicon 1 (lsi1), defective in active Si uptake, and its wild-type counterpart (cv. Oochikara). Plants were inoculated with B. oryzae after growing for 35 days in a hydroponic culture amended with 0 or 2 mMol Si. The components of host resistance evaluated were incubation period (IP), relative infection efficiency (RIE), area under brown spot progress curve (AUBSPC), final lesion size (FLS), rate of lesion expansion (r), and area under lesion expansion progress curve (AULEPC). Si content from both Oochikara and lsi1 in the +Si treatment increased in leaf tissue by 219 and 178%, respectively, over the nonamended controls. Plants from Oochikara had 112% more Si in leaf tissue than plants from lsi1. The IP of brown spot from Oochikara increased approximately 6 h in the presence of Si and the RIE, AUBSPC, FLS, r, and AULEPC were significantly reduced by 65, 75, 33, 36, and 35%, respectively. In the presence of Si, the IP increased 3 h for lsi1 but the RIE, AUBSPC, FLS, r, and AULEPC were reduced by only 40, 50, 12, 21, and 12%, respectively. The correlation between Si leaf content and IP was significantly positive but Si content was negatively correlated with RIE, AUBSPC, FLS, r, and AULEPC. Single degree-of-freedom contrasts showed that Oochikara and lsi1 supplied with Si were significantly different from those not supplied with Si for all components of resistance evaluated. This result showed that a reduced Si content in tissues of plants from lsi1 dramatically affected

  8. Starch and Prolamin Level in Single and Double High-Lysine Barley Mutants

    Kreis, M.; Doll, Hans

    1980-01-01

    At maturity the high-lysine barley (Hordeum vulgare L.) Ris0 mutants 1508, 527 and 29 kernels contained about 20% less starch and twice as much free sugars as the parent varieties Bomi and Carlsberg II. An enhanched effect on starch reduction and free sugar accumulation was observed during kernel...... development when the single mutants 527 and 29 are combined with the mutant 1508. At maturity, kernels of the double mutants 527/1508 and 29/1508 contained, respectively, 68 and 43% less starch than Bomi. The double mutant 29/1508 kernel had a slightly lower prolamin content than mutant 1508 which is the most...... prolamin-deficient single mutant. In the double mutant 527/1508, however, an almost complete suppression of prolamin synthesis was observed during kernel development. The percentage of lysine in the seed proteins of the double mutants was about the same as in the most extreme single mutant 1508. Based...

  9. Effects of Long-Term Fertilization on Organic Carbon and Nitrogen Accumulation and Activity in a Paddy Soil in Double Cropping Rice Area in Dongting Lake of China%长期施肥对洞庭湖双季稻区水稻土有机碳、氮积累及其活性的影响

    李文军; 彭保发; 杨奇勇

    2015-01-01

    Objective]Soil organic matter and its activity are essential indexes for assessing soil fertility, so the responses of total organic carbon (TOC) and nitrogen (TN) accumulation and its activity to various long-term fertilization in a double cropping rice soil were studied in Dongting Lake region, China, which can provide a scientific basis for improving fertilization management and soil fertility in paddy soils.[Method]Based on a national experimental platform which was arranged in the Hanshou county, Hunan province, test samples in the surface (0-20 cm) and subsurface (20-40 cm) of a paddy soil after 26 years of fertilization treatments were collected and SOC, TN content and storage were measured, as well as soil microbial biomass carbon (MBC) and nitrogen (MBN), dissolved organic carbon (DOC) and nitrogen (DON) contents were also analyzed. The experiment included six treatments: (1) CK, unfertilized control; (2) CF, farmers’ practice of applying chemical fertilizer NPK; (3) NK, application of chemical fertilizer NK; (4) NPK, balanced application of chemical fertilizer NPK; (5) LOM, combined application of chemical fertilizer NPK and 30% organic fertilizer; (6) HOM, combined application of chemical fertilizer NPK and 60% organic fertilizer.[Result]The content of TOC at 0-20 cm soil layer changed slightly when no fertilizer applied for 26 years and its value only increased by 0.64 g·kg-1 throughout the period, suggesting that long-term cropping rice was beneficial to TOC sequestration. After long-term application of chemical or organic fertilizer, the content of TOC and TN in two soil layers increased significantly (P0.05) among the CF, NK and NPK treatments. With the deepening of soil, the proportion of labile organic N fractions to TN and microbial quotient decreased, but the proportion of DOC to TOC increased. No matter which soil layer was concerned, the MBC/TOC, DOC/TOC, MBN/TN and DON/TN ratios in soil increased when fertilization was adopted, and the

  10. Association of arsenic concentration and speciation with straighthead disease in US produced rice

    Recent reports have indicated that rice when grown under anaerobic flooded field conditions can accumulate high levels of grain arsenic (As). This is a public health concern due to the high daily consumption of rice by some populations. The As-based herbicide (monosodium methanearsonate, MSMA) has ...

  11. Blast-Resistance Inheritance of Space-Induced Rice Lines and Their Genomic Polymorphism by Microsatellite Markers

    XIAO Wu-ming; YANG Qi-yun; CHEN Zhi-qiang; WANG Hui; GUO Tao; LIU Yong-zhu; ZHU Xiao-yuan

    2009-01-01

    To understand the resistance inheritance basis of space-induced rice lines to blast,and to probe mutants'genomic DNA polymorphism compared with ground control by microsatellite markers,three space-induced lines were crossed with a highly susceptible variety LTH,and their F1 and F2 populations were inoculated by two representative blast isolates with broad pathogenicity to analyze their resistance inheritance basis.Meanwhile three mutant lines and the ground control were analyzed by 225 rice SSR(simple sequence repeat)primer pairs selected throughout the 12 chromosomes of whole rice genome,to scan the mutagenesis in genome of the mutant lines.The results indicated the blast-resistant genes harbored in these mutant lines were dominant.It was demonstrated that the resistance of mutant H1 to isolate GD0193 and GD3286 was controlled by a single gene,respectively;while mutants H2 and H3 were controlled by two pairs of major genes against isolate GD3286 and H2 showed complicated genetic mechanism to isolate GD0193.H3's resistance to isolate GD0193 was verified to be controlled by a single gene.According to the results of SSR analysis,three mutant lines showed different mutant rates as compared with the ground control,and the mutant rates also varied.Resistance genes can be induced from rice by space mutation,and different genomic variations were detected in blast-resistant lines.

  12. Effects of Bicarbonate and High pH Conditions on Zinc and Other Nutrients Absorption in Rice

    LU Zhong-xian; MENG Fan-hua; S. VILLAREAL; WEI You-zhang; YU Xiao-ping; YANG Xiao-e; K. L. HEONG; LIN Jian-jun; HU Cui; LIU Jian-xiang

    2004-01-01

    Zinc deficiency was widely observed in calcareous soil where bicarbonate and high pH were always related with low zinc availability. In a hydroponic experiment, one zinc-efficient rice (IR36) and one zinc-inefficient rice (IR26) genotypes were employed to investigate the effects of bicarbonate and high pH conditions on absorption, transport of zinc and other nutrients (P, K, Ca, Mg,Fe, Cu, Mn) in rice. As compared with the control, high pH inhibited absorption, translocation and accumulation of zinc and other nutrients in both rice genotypes. Bicarbonate had minor effect on zinc-efficient rice genotype (IR36) whereas it could decrease zinc and other nutrient absorption in zinc-inefficient rice genotype (IR26). These results implied that increasing rice tolerance to bicarbonate is one of the most important strategies to improve rice adaptation for zinc-deficit calcareous soil.

  13. Efficiency of nitrogen fertilizers for rice

    Roger, Pierre-Armand; I. F. Grant; Reddy, P. M.; Watanabe, I.

    1987-01-01

    The photosynthetic biomass that develops in the floodwater of wetland rice fields affects nitrogen dynamics in the ecosystem. This review summarizes available data on the nature, productivity, and composition of the photosynthetic aquatic biomass, and its major activities regarding the nitrogen cycle, i.e., nitrogen fixation by free living blue-green algae and #Azolla$, nitrogen trapping, nitrogen accumulation at the soil surface, its effect on nitrogen losses by ammonia volatilization, nitro...

  14. Jasmonate induction of the monoterpene linalool confers resistance to rice bacterial blight and its biosynthesis is regulated by JAZ protein in rice.

    Taniguchi, Shiduku; Hosokawa-Shinonaga, Yumi; Tamaoki, Daisuke; Yamada, Shoko; Akimitsu, Kazuya; Gomi, Kenji

    2014-02-01

    Jasmonic acid (JA) is involved in the regulation of host immunity in plants. Recently, we demonstrated that JA signalling has an important role in resistance to rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice. Here, we report that many volatile compounds accumulate in response to exogenous application of JA, including the monoterpene linalool. Expression of linalool synthase was up-regulated by JA. Vapour treatment with linalool induced resistance to Xoo, and transgenic rice plants overexpressing linalool synthase were more resistance to Xoo, presumably due to the up-regulation of defence-related genes in the absence of any treatment. JA-induced accumulation of linalool was regulated by OsJAZ8, a rice jasmonate ZIM-domain protein involving the JA signalling pathway at the transcriptional level, suggesting that linalool plays an important role in JA-induced resistance to Xoo in rice.

  15. Construction of a Rice Glvcosvltransferase Phylogenomic Data base and Identification of Rice-Diverged Glvcosvltransferases

    Pei-Jian Cao; Laura E.Bartley; Ki-Hong Jung; Pamela C.Ronald

    2008-01-01

    GlycosyItransferases(GTs;Ec 2.4.x.y)constitute a large group of enzymes that form glycosidic bonds through transfer of sugars from activated donor molecules to acceptor molecules.GTs are critical to the biosynthesis of plant cell walls,among other diverse functions.Based on the Carbohydrate-Active enZymes(CAZy)database and sequence similarity searches,we have identified 609 potentiaI GT genes(loci)corresponding to 769 transcripts(gene models)in rice (Oryza sativa),the reference monocotyledonous species.Using domain composition and sequence similarity,these rice GTs were classified into 40 CAZy families plus an additionaI unknown class.We found that two Pfam domains of unknown function,PF04577 and PF04646,are associated with GT families GT61 and GT31,respectively.To facilitate functional analysis of this important and large gene family,we created a phylogenomic Rice GT Database(http://ricephylogenomics.ucdavis.edu/cellwalls/gt/).Through the database.severaI classes of functionaI genomic data,including mutant lines and gene expression data,can be displayed for each rice GT in the context of a phylogenetic tree,allowing for comparative analysis both within and between GT families.Comprehensive digital expression analysis of public gene expression data revealed that most(~80%)rice GTs are expressed.Based on analysis with Inparanoid,we identified 282'rice-diverged'GTs that lack orthologs in sequenced dicots(Arabidopsis thaliana,Populus tricocarpa,Medicago truncatula.and Ricinus communis).Combining these analyses,we identified 33 rice-diverged GT genes(45 gene models)that are highly expressed in above-ground,vegetative tissues.From the literature and this analysis,21 of these Ioci are excellent targets for functional examination toward understanding and manipuIating grass cell wall qualities.Study of the remainder may reveal aspects of hormone and protein metabolism that are critical for rice biology.This list of 33 genes and the Rice GT Database will facilitate the

  16. Vacuolar processing enzyme plays an essential role in the crystalline structure of glutelin in rice seed.

    Kumamaru, Toshihiro; Uemura, Yuji; Inoue, Yoshimi; Takemoto, Yoko; Siddiqui, Sadar Uddin; Ogawa, Masahiro; Hara-Nishimura, Ikuko; Satoh, Hikaru

    2010-01-01

    To identify the function of genes that regulate the processing of proglutelin, we performed an analysis of glup3 mutants, which accumulates excess amounts of proglutelin and lack the vacuolar processing enzyme (VPE). VPE activity in developing seeds from glup3 lines was reduced remarkably compared with the wild type. DNA sequencing of the VPE gene in glup3 mutants revealed either amino acid substitutions or the appearance of a stop codon within the coding region. Microscopic observations showed that alpha-globulin and proglutelin were distributed homogeneously within glup3 protein storage vacuoles (PSVs), and that glup3 PSVs lacked the crystalline lattice structure typical of wild-type PSVs. This suggests that the processing of proglutelin by VPE in rice is essential for proper PSV structure and compartmentalization of storage proteins. Growth retardation in glup3 seedlings was also observed, indicating that the processing of proglutelin influences early seedling development. These findings indicate that storage of glutelin in its mature form as a crystalline structure in PSVs is required for the rapid use of glutelin as a source of amino acids during early seedling development. In conclusion, VPE plays an important role in the formation of protein crystalline structures in PSVs.

  17. TALEN utilization in rice genome modifications.

    Li, Ting; Liu, Bo; Chen, Chih Ying; Yang, Bing

    2014-08-15

    Transcription activator-like effector nucleases (TALENs), the newly developed and powerful genetic tools for precise genome editing, are fusion proteins of TAL effectors as DNA binding domains and the cleavage domain of FokI endonuclease. As a pair, the central repeat regions of TALENs determine the DNA binding specificity for the two sub-target sites; and the dimeric non-specific FokI cleavage domains cause a DNA double strand break (DSB) between the bound sequences. In vivo, cells repair the DSBs through either non-homologous end joining (NHEJ) pathway or homologous recombination (HR) pathway. Various methods have been developed for easy and fast assembly of TALEN genes for their utilization in a variety of eukaryotic cells or organisms. Here we present a TALEN-based rice genome modification protocol including constructing modularly assembled TALENs, rice transformation, and mutant screening.

  18. Global Identification of Genes Specific for Rice Meiosis.

    Zhang, Bingwei; Xu, Meng; Bian, Shiquan; Hou, Lili; Tang, Ding; Li, Yafei; Gu, Minghong; Cheng, Zhukuan; Yu, Hengxiu

    2015-01-01

    The leptotene-zygotene transition is a major step in meiotic progression during which pairing between homologous chromosomes is initiated and double strand breaks occur. OsAM1, a homologue of maize AM1 and Arabidopsis SWI1, encodes a protein with a coiled-coil domain in its central region that is required for the leptotene-zygotene transition during rice meiosis. To gain more insight into the role of OsAM1 in rice meiosis and identify additional meiosis-specific genes, we characterized the transcriptomes of young panicles of Osam1 mutant and wild-type rice plants using RNA-Seq combined with bioinformatic and statistical analyses. As a result, a total of 25,750 and 28,455 genes were expressed in young panicles of wild-type and Osam1 mutant plants, respectively, and 4,400 differentially expressed genes (DEGs; log2 Ratio ≥ 1, FDR ≤ 0.05) were identified. Of these DEGs, four known rice meiosis-specific genes were detected, and 22 new putative meiosis-related genes were found by mapping these DEGs to reference biological pathways in the KEGG database. We identified eight additional well-conserved OsAM1-responsive rice meiotic genes by comparing our RNA-Seq data with known meiotic genes in Arabidopsis and fission yeast.

  19. Determinants for grading Malaysian rice

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  20. [Mechanisms for the increased fertilizer nitrogen use efficiency of rice in wheat-rice rotation system under combined application of inorganic and organic fertilizers].

    Liu, Yi-Ren; Li, Xiang; Yu, Jie; Shen, Qi-Rong; Xu, Yang-Chun

    2012-01-01

    A pot experiment was conducted to study the effects of combined application of organic and inorganic fertilizers on the nitrogen uptake by rice and the nitrogen supply by soil in a wheat-rice rotation system, and approach the mechanisms for the increased fertilizer nitrogen use efficiency of rice under the combined fertilization from the viewpoint of microbiology. Comparing with applying inorganic fertilizers, combined application of organic and inorganic fertilizers decreased the soil microbial biomass carbon and nitrogen and soil mineral nitrogen contents before tillering stage, but increased them significantly from heading to filling stage. Under the combined fertilization, the dynamics of soil nitrogen supply matched best the dynamics of rice nitrogen uptake and utilization, which promoted the nitrogen accumulation in rice plant and the increase of rice yield and biomass, and increased the fertilizer nitrogen use efficiency of rice significantly. Combined application of inorganic and organic fertilizers also promoted the propagation of soil microbes, and consequently, more mineral nitrogen in soil was immobilized by the microbes at rice early growth stage, and the immobilized nitrogen was gradually released at the mid and late growth stages of rice, being able to better satisfy the nitrogen demand of rice in its various growth and development stages.

  1. Rice (Oryza) hemoglobins

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  2. Distribution of selenium and cadmium in soil-rice system of selenium-rich area in Hainan, China.

    Wang, Dengfeng; Wei, Zhiyuan; Tang, Shumei; Qi, Zhiping

    2014-09-01

    Rice, which is the staple food in East Asia, is a source of Selenium (Se) and Cadmium (Cd). The distribution of Se and Cd in soil-rice system is significant to human nutrition and public health. This study is to explore the distribution of Se and Cd in arable land soils and their distribution in polished rice and stalks of Se-rich area. A total of 63 soil samples and 126 rice samples (63 groups of rice grains and stalk samples) were collected from West Hainan Island to determine Se and Cd concentrations. The results suggested the concentration of Se in soil was higher than average level in China, and Cd content was lower than the agricultural land-use threshold of China. The distribution of Se and Cd in arable land soil was primarily determined by diagenesis and mineralization. Se and Cd were more inclined to accumulate in stalks than rice grains, and the contents in polished rice were correlated with that in stalk. Acidification of arable land soil will threaten human nutrition and health for the bioaccumulation factor of Se in polished rice decreased significantly with the decrease of soil pH, while that of Cd in polished rice increased significantly. Therefore, application of lime or alkaline fertilizers in arable land soil of Se-rich area can promote the accumulation of Se in polished rice but reduced the intake of Cd in rice crops.

  3. Comparative Proteomic Analysis of Rice Shoots Exposed to High Arsenate

    Yanli Liu; Ming Li; Chao Han; Fengxia Wu; Bingkun Tu; Pingfang Yang

    2013-01-01

    Consumption of arsenic contaminated water and cereals is a serious threat to humans all over the world. Rice (Oryza sativa“Nipponbare”), as a main cereal crop, can accumulate arsenic more than 10-fold that of in other cereals. To gain a comprehensive understanding of the response of rice subjected to 100 mM arsenate stress, a comparative proteomic analysis of rice shoots in combination with morphological and biochemical investigations have been performed in this study. The results demonstrated that arsenate suppressed the growth of rice seedlings, destroyed the cellular ultra-structure and changed the homeostasis of reactive oxygen species. Moreover, a total of 38 differentially displayed proteins, which were mainly involved in metabolism, redox and protein-metabolism, were identified. The data suggest the arsenic can inhibit rice growth through negatively affecting chloroplast structure and photosynthesis. In addition, upregulation of the proteins involved in redox and protein metabolism might help the rice to be resistant or tolerant to arsenic toxicity. In general, this study improves our understanding about the rice arsenic responsive mechanism.

  4. Health-Promoting Compounds in Pigmented Thai and Wild Rice

    Valentina Melini

    2017-01-01

    Full Text Available Organic pigmented Thai rice and wild rice are commonly available in specialized Italian markets and food shops, and they are gaining popularity among consumers demanding healthy foods. Indeed, the typical colour of kernels, which is the unique characteristic of pigmented cereals, is due to the accumulation of pigments that are also responsible for a number of healthy effects. The aim of this study was to provide a portrait of two organic pigmented Thai rice varieties from Thailand and one wild rice variety from Canada, imported into Italy and at Italian consumers’ disposal. To this end, the proximate composition and the content of health-promoting compounds, such as carotenoids, anthocyanins and phenolic compounds, were determined in Thai and wild rice. Moreover, the effect of cooking on phytochemicals was assessed, in order to provide reliable data on the dietary intake of bioactive compounds by samples under investigation. Results show that studied samples have a content of phytochemicals higher than white rice and comparable to other cereals. The cooking process determined a decrease of bioactive compounds in all varieties under investigation. However, some samples were found more resistant to cooking stress, and some phytochemicals were little affected by this process. Therefore, pigmented Thai and wild rice may represent a valuable source of healthy compounds and an alternative to other wholesome foods required by consumers.

  5. Super Rice Breeding in China

    2001-01-01

    @@I. Demand for super high yield rice in China   Rice is one of the main staple food in China. The performance of rice sector in production and yield had been very impressive in the last four decades. However, rice production and yield has stagnated since 1990.

  6. Oxygen dynamics in submerged rice (Oryza sativa L.)

    Colmer, Timothy D.; Pedersen, Ole

    2008-01-01

    Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...... from roots showed an initial peak following shoot illumination.  O2 dynamics in shoots and roots of submerged rice were monitored during light and dark periods, using O2 microelectrodes. Tissue sugar concentrations were also measured.  On illumination of shoots of submerged rice, pO2 increased rapidly...... of magnitude higher than in darkness, enhancing also pO2 in roots.The initial peak in pO2 following illumination of submerged rice was likely to result from high initial rates of net photosynthesis, fuelled by CO2 accumulated during the dark period. Nevertheless, since sugars decline with time in submerged...

  7. Variation among Rice Cultivars in Root Acidification and Its Relation to Cadmium Uptake

    LIU Jian-guo; XU Hai; CAI Guo-liang; QIAN Min; WANG De-ke; ZHU Qing-sen

    2006-01-01

    To understand the mechanisms of Cd uptake and accumulation in rice, soil acidification by root activities was investigated in six rice cultivars differing in Cd accumulation. The results showed a significant difference among the cultivars in pH of pot water and root exudate. Soil acidification abilities varied with rice cultivars. Both pH of pot water and root exudate were lower in indica cultivars than in japonica ones. The difference in root acidification was larger in Cd treated cultivars than the control. Under Cd stress, the pH of pot water and root exudate correlated negatively and significantly with Cd concentrations in rice plants. It was suggested that the soil acidification by root exudates, especially in Cd contaminated soils, may be one of the mechanisms responsible for Cd uptake in rice cultivars.

  8. Methods of producing protoporphyrin IX and bacterial mutants therefor

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  9. Bacterial accumulation in viscosity gradients

    Waisbord, Nicolas; Guasto, Jeffrey

    2016-11-01

    Cell motility is greatly modified by fluid rheology. In particular, the physical environments in which cells function, are often characterized by gradients of viscous biopolymers, such as mucus and extracellular matrix, which impact processes ranging from reproduction to digestion to biofilm formation. To understand how spatial heterogeneity of fluid rheology affects the motility and transport of swimming cells, we use hydrogel microfluidic devices to generate viscosity gradients in a simple, polymeric, Newtonian fluid. Using video microscopy, we characterize the random walk motility patterns of model bacteria (Bacillus subtilis), showing that both wild-type ('run-and-tumble') cells and smooth-swimming mutants accumulate in the viscous region of the fluid. Through statistical analysis of individual cell trajectories and body kinematics in both homogeneous and heterogeneous viscous environments, we discriminate passive, physical effects from active sensing processes to explain the observed cell accumulation at the ensemble level.

  10. Endosperm Development in Autotetraploid Rice

    WANG Lan; LIU Xiang-dong; LU Yong-gen; FENG Jiu-huan; XU Xue-bin; XU Shi-xiong (S.Y.Zee)

    2005-01-01

    By using the laser scanning confocal microscope and plastic (Leica 7022 historesin embedding kit) semi-thin sectioningtechnique, comparative studies on the development of endosperm were carried out between autotetraploid and diploid rices. Aboutone third of the ovaries in the autotetraploid showed normal endosperm development as those in the diploid. In these ovaries, one ofthe polar nuclei would fuse with the sperm nucleus, and the primary endosperm nucleus formed and underwent the first division in 4hours after pollination; the anticlinal wall began to grow centripetally between the free nuclei starting from the wall ingrowths of theembryo sac near the micropylar end, and some of the phragmoplasts formed transformed into periclinal walls. In addition, some of thecell wall situated in the middle of the endosperm appeared to originate from phragmoplasts, whereas others seemed to developrandomly without the obvious formation of phragmoplasts. Cellulose began to accumulate in the wall of aleurone cell layer at 6 daysafter pollination. The cellulose wall of the cells of the aleurone cell layer appeared to have completely formed within 7 to 8 days afterpollination. On the other hand, about two thirds of the ovaries in the autotetraploid showed abnormality in endosperm developmentwith various types, such as non-fertilization, abnormal fertilization, endosperm development-delay and non-synchronization in thedevelopment of cellulose wall of cells of the aleurone layer. These abnormalities usually resulted in decreased seed setting inautotetraploid rice.

  11. [Influence of weeds in Echinochloa on growth and yield of rice].

    Zhang, Zi-Chang; Li, Yong-Feng; Zhang, Bin; Yang, Xia

    2014-11-01

    In order to investigate effects of different barnyardgrass species on growth and yiled of rice, two rice cultivars, Xinliangyou 6 hao (an indica hybrid cultivar) and Nanjing 46 (a japonica cultivar), were co-cultured with four barnyardgrass species grown at a density of six plants · m(-2) from 10 days after transplanting to maturity. The treatments were designed as follow: weed free (control), rice with Echinochloa crusgalli var. mitis (T1), rice with E. crusgalli (T2), rice with E. crusgali var. zelayensis (T3), and rice with E. colonum (T4). The result showed that barnyardgrass-induced reductions in grain yield of rice were obviously different among the four treatments. T1, T2 and T3 treatments reduced the grain yield of indicia cultivar by 19.2%, 10.8% and 21.9%, and the respective reductions in japonica cultivar were 39.7%, 25.3% and 47.3%, re- spectively. However, no significant difference was detected for T4 treatment. During rice co-culture with barnyardgrass, T1, T2 and T3 significantly reduced rice dry matter accumulation at maturity, flag leaf photosynthetic rate, root oxidation activity and the activity of adenosine triphosphate enzyme (ATPsse) in rice grains at the filling stage, and the magnitude of decrease was in the order of T3 > T1 > T2, while no significant difference was observed between T4 and CK. In addition, all treatments had no effects on the final tiller number and plant height of rice. It indicated that the negative effect of barnyardgrass on rice growth and yield differed among the four species of barnyardgrass, in the order of T3 > T1 > T2 > T4. Barnyardgrass reduced the flag leaf photosynthetic rate of rice, both root oxidation activity and ATPsse activity in grains, which resulted in the reduction in final productivity of rice when co-cultured with barnyardgrass.

  12. Rice Germplasm Resources in China

    YINGCunshan

    1994-01-01

    China is one of the origin countries in Asia of cultiv ated rice (O. sativaL.), and rice is one of the aged-long food crops in the country. The results of the 14C evaluation on the carbonified rice grains unearthed from Hemudu in Yuyao County and Luojiajiao in Tongxiang County of Zhejiang Province indicated that rice in these area has been planted more than 7,000 yrs and indica (hsien) and japonica (keng) rices coexisted with each other.

  13. Constitutive Expression of OsIAA9 Affects Starch Granules Accumulation and Root Gravitropic Response in Arabidopsis.

    Luo, Sha; Li, Qianqian; Liu, Shanda; Pinas, Nicholaas M; Tian, Hainan; Wang, Shucai

    2015-01-01

    Auxin/Indole-3-Acetic Acid (Aux/IAA) genes are early auxin response genes ecoding short-lived transcriptional repressors, which regulate auxin signaling in plants by interplay with Auxin Response Factors (ARFs). Most of the Aux/IAA proteins contain four different domains, namely Domain I, Domain II, Domain III, and Domain IV. So far all Aux/IAA mutants with auxin-related phenotypes identified in both Arabidopsis and rice (Oryza sativa) are dominant gain-of-function mutants with mutations in Domain II of the corresponding Aux/IAA proteins, suggest that Aux/IAA proteins in both Arabidopsis and rice are largely functional redundantly, and they may have conserved functions. We report here the functional characterization of a rice Aux/IAA gene, OsIAA9. RT-PCR results showed that expression of OsIAA9 was induced by exogenously applied auxin, suggesting that OsIAA9 is an auxin response gene. Bioinformatic analysis showed that OsIAA9 has a repressor motif in Domain I, a degron in Domain II, and the conserved amino acid signatures for protein-protein interactions in Domain III and Domain IV. By generating transgenic plants expressing GFP-OsIAA9 and examining florescence in the transgenic plants, we found that OsIAA9 is localized in the nucleus. When transfected into protoplasts isolated from rosette leaves of Arabidopsis, OsIAA9 repressed reporter gene expression, and the repression was partially released by exogenously IAA. These results suggest that OsIAA9 is a canonical Aux/IAA protein. Protoplast transfection assays showed that OsIAA9 interacted ARF5, but not ARF6, 7, 8 and 19. Transgenic Arabidopsis plants expressing OsIAA9 have increased number of lateral roots, and reduced gravitropic response. Further analysis showed that OsIAA9 transgenic Arabidopsis plants accumulated fewer granules in their root tips and the distribution of granules was also affected. Taken together, our study showed that OsIAA9 is a transcriptional repressor, and it regulates gravitropic

  14. Constitutive expression of OsIAA9 affects starch granules accumulation and root gravitropic response in Arabidopsis

    Sha eLuo

    2015-12-01

    Full Text Available Auxin/Indole-3-Acetic Acid (Aux/IAA genes are early auxin response genes ecoding short-lived transcriptional repressors, which regulate auxin signaling in plants by interplay with Auxin Response Factors (ARFs. Most of the Aux/IAA proteins contain four different domains, namely Domain I, Domain II, Domain III and Domain IV. So far all Aux/IAA mutants with auxin-related phenotypes identified in both Arabidopsis and rice (Oryza sativa are dominant gain-of-function mutants with mutations in Domain II of the corresponding Aux/IAA proteins, suggest that Aux/IAA proteins in both Arabidopsis and rice are largely functional redundantly, and they may have conserved functions. We report here the functional characterization of a rice Aux/IAA gene, OsIAA9. RT-PCR results showed that expression of OsIAA9 was induced by exogenously applied auxin, suggesting that OsIAA9 is an auxin response gene. Bioinformatic analysis showed that OsIAA9 has a repressor motif in Domain I, a degron in Domain II, and the conserved amino acid signatures for protein-protein interactions in Domain III and Domain IV. By generating transgenic plants expressing GFP-OsIAA9 and examining florescence in the transgenic plants, we found that OsIAA9 is localized in the nucleus. When transfected into protoplasts isolated from rosette leaves of Arabidopsis, OsIAA9 repressed reporter gene expression, and the repression was partially released by exogenously IAA. These results suggest that OsIAA9 is a canonical Aux/IAA protein. Protoplast transfection assays showed that OsIAA9 interacted ARF5, but not ARF6, 7, 8 and 19. Transgenic Arabidopsis plants expressing OsIAA9 have increased number of lateral roots, and reduced gravitropic response. Further analysis showed that OsIAA9 transgenic Arabidopsis plants accumulated fewer granules in their root tips and the distribution of granules was also affected. Taken together, our study showed that OsIAA9 is a transcriptional repressor, and it regulates

  15. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-12-22

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  16. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    Zhouping Liu

    2015-12-01

    Full Text Available Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM. This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  17. Methylmercury varies more than one order of magnitude in commercial European rice.

    Brombach, Christoph-Cornelius; Manorut, Parinda; Kolambage-Dona, Piumi P P; Ezzeldin, Mohammed Farouk; Chen, Bin; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2017-01-01

    Rice is known to accumulate methylmercury (MeHg) in the rice grains. MeHg as a neurotoxin impacts on the human central nervous systems and especially on the developing brain. In this exploratory study, 87 commercial rice products sold in Europe, including nine baby-rice products, were analyzed for total Hg and MeHg content. MeHg concentration in all rice products investigated range from 0.11 to 6.45μgkg(-1) with an average value of 1.91±1.07μgkg(-1) and baby-rice is not significantly different from other rice products. Total Hg ranges from 0.53 to 11.1μgkg(-1) with an average of 3.04±2.07μgkg(-1). MeHg concentrations in all rice products studied in this work would not exceed the provisional tolerable weekly intake (PTWI). 30% of all commercial market rice products exceeded 10% of the PTWI calculated for toddlers or 13% of products for adults with rice based diet.

  18. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  19. Plant regeneration from mesophyll protoplast of indica rice Qiugui'ai 11 (Oryza sativa L.)

    JIANYuyu; JintaanankulSuwan

    1998-01-01

    In the recent decade, plant regeneration from protoplast has been obtained through embryogenic cell suspension cultures of rice. However, not only the establishment of embryogenic call suspension cultures of rice was difficult, but also the protoplasts became less and less regenerable and the genetic change was gradu ally accumulated during the prolonged culture.Since 1976 (Deka.), extensive efforts have been made to induce sustained division and regenerate plants from rnesophyll protoplasts of rice, but not successful.

  20. Molecular dissection of the roles of phytochrome in photoperiodic flowering in rice.

    Osugi, Asami; Itoh, Hironori; Ikeda-Kawakatsu, Kyoko; Takano, Makoto; Izawa, Takeshi

    2011-11-01

    Phytochromes mediate the photoperiodic control of flowering in rice (Oryza sativa), a short-day plant. Recent molecular genetics studies have revealed a genetic network that enables the critical daylength response of florigen gene expression. Analyses using a rice phytochrome chromophore-deficient mutant, photoperiod sensitivity5, have so far revealed that within this network, phytochromes are required for expression of Grain number, plant height and heading date7 (Ghd7), a floral repressor gene in rice. There are three phytochrome genes in rice, but the roles of each phytochrome family member in daylength response have not previously been defined. Here, we revealed multiple action points for each phytochrome in the critical daylength response of florigen expression by using single and double phytochrome mutant lines of rice. Our results show that either phyA alone or a genetic combination of phyB and phyC can induce Ghd7 mRNA, whereas phyB alone causes some reduction in levels of Ghd7 mRNA. Moreover, phyB and phyA can affect Ghd7 activity and Early heading date1 (a floral inducer) activity in the network, respectively. Therefore, each phytochrome gene of rice has distinct roles, and all of the phytochrome actions coordinately control the critical daylength response of florigen expression in rice.

  1. Effects of Nitrogen Application Level on Rice Nutrient Uptake and Ammonia Volatilization

    YU Qiao-gang; YE Jing; YANG Shao-na; FU Jian-rong; MA Jun-wei; SUN Wan-chun; JIANG Li-na

    2013-01-01

    The effects of different nitrogen application levels on nutrient uptake and ammonia volatilization were studied with the rice cultivar Zheyou 12 as a material.The accumulative amounts of nitrogen,phosphorus and potassium in rice plants across all growth stages showed a trend to increase with increasing nitrogen application levels from 0 to 270 kg/hm2,but decreased at nitrogen application levels exceeding 270 kg/hm2.Moreover,the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants was increased by application of organic manure in combination with 150 kg/hm2 nitrogen.The nitrogen uptake was high during the jointing to heading stages.Correlation analysis showed that rice yield was positively correlated with the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants.The highest correlation coefficient observed was between the amount of nitrogen uptake and rice yield.The rate and accumulative amounts of ammonia volatilization increased with increasing nitrogen fertilizer application level.Compared with other stages,the rate and accumulative amount of ammonia volatilization were higher after base fertilizer application.The ammonia volatilization rates in response to the nitrogen application levels of 270 kg/hm2 and 330 kg/hm2 were much higher than those in the other treatments.The loss of nitrogen through ammonia volatilization accounted for 23.9% of the total applied nitrogen at the nitrogen application level of 330 kg/hm2.

  2. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice — A field study over four rice seasons in Hunan, China

    Chen, De; Guo, Hu; Li, Ruiyue [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Li, Lianqing, E-mail: lqli@njau.edu.cn [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Pan, Genxing [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Chang, Andrew [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States); Joseph, Stephen [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-01-15

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha{sup −1}. Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35–91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69–80% and 72–80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. - Highlights: • Biochar sustainably reduced soil Cd availability and Cd translocation in rice plant. • Indica conventional cultivars had lower Cd but higher Zn in grains than hybrid ones. • Biochar significantly reduced grain Cd and Cd/Zn ratio

  3. N-glycan containing a core α1,3-fucose residue is required for basipetal auxin transport and gravitropic response in rice (Oryza sativa).

    Harmoko, Rikno; Yoo, Jae Yong; Ko, Ki Seong; Ramasamy, Nirmal Kumar; Hwang, Bo Young; Lee, Eun Ji; Kim, Ho Soo; Lee, Kyung Jin; Oh, Doo-Byoung; Kim, Dool-Yi; Lee, Sanghun; Li, Yang; Lee, Sang Yeol; Lee, Kyun Oh

    2016-10-01

    In plants, α1,3-fucosyltransferase (FucT) catalyzes the transfer of fucose from GDP-fucose to asparagine-linked GlcNAc of the N-glycan core in the medial Golgi. To explore the physiological significance of this processing, we isolated two Oryza sativa (rice) mutants (fuct-1 and fuct-2) with loss of FucT function. Biochemical analyses of the N-glycan structure confirmed that α1,3-fucose is missing from the N-glycans of allelic fuct-1 and fuct-2. Compared with the wild-type cv Kitaake, fuct-1 displayed a larger tiller angle, shorter internode and panicle lengths, and decreased grain filling as well as an increase in chalky grains with abnormal shape. The mutant allele fuct-2 gave rise to similar developmental abnormalities, although they were milder than those of fuct-1. Restoration of a normal tiller angle in fuct-1 by complementation demonstrated that the phenotype is caused by the loss of FucT function. Both fuct-1 and fuct-2 plants exhibited reduced gravitropic responses. Expression of the genes involved in tiller and leaf angle control was also affected in the mutants. We demonstrate that reduced basipetal auxin transport and low auxin accumulation at the base of the shoot in fuct-1 account for both the reduced gravitropic response and the increased tiller angle.

  4. Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

    Hove-Jensen, Bjarne; Nygaard, Per

    1982-01-01

    From an Escherichia coli purine auxotroph a mutant defective in phosphoribosylpyrophosphate (PRib-PP) synthetase has been isolated and partially characterized. In contrast to the parental strain, the mutant was able to grow on nucleosides as purine source, whereas growth on purine bases was reduced......, stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib...

  5. Genetic base of Brazilian irrigated rice cultivars

    Hudson de Oliveira Rabelo

    2015-08-01

    Full Text Available The aim of this study was to estimate the genetic base of Brazilian irrigated rice cultivars released in the period from 1965 to 2012. The genealogies of the cultivars were obtained based on information from marketing folders, websites, crossings records, and scientific articles. The following factors were calculated: relative genetic contribution (RGC, accumulated genetic contribution (AGC, frequency (in percentage of each ancestor in the genealogy (FAG, number of ancestors that constitute each cultivar (NAC,number of ancestors responsible for 60%, 70%, 80% and 90% of the genetic base (NAGB, and average number of ancestor per cultivar (ANAC. The cultivars were also grouped based on the period of release (1965-1980, 1981-1990, 1991-2000 and 2001-2012. For each grouping, the previously described factors were also estimated. A total of 110 cultivars were studied and it was concluded that the genetic base of Brazilian irrigated rice cultivars is narrow.

  6. Glutinous Rice in Pineapple

    1998-01-01

    Ingredients: 50 grams glutinous rice, one pineapple, 20 grams dried fruits (raisins, walnuts. Chinese wolfberry, Chinese dates, lotus seeds, lily petals, kidney beans and peanuts) Seasonings: 5 grams rock sugar, 5 grams salad oil. Method:

  7. Guanine nucleotide exchange factor 2 for Rab5 proteins coordinated with GLUP6/GEF regulates the intracellular transport of the proglutelin from the Golgi apparatus to the protein storage vacuole in rice endosperm.

    Wen, Liuying; Fukuda, Masako; Sunada, Mariko; Ishino, Sonoko; Ishino, Yoshizumi; Okita, Thomas W; Ogawa, Masahiro; Ueda, Takashi; Kumamaru, Toshihiro

    2015-10-01

    Rice glutelin polypeptides are initially synthesized on the endoplasmic reticulum (ER) membrane as a proglutelin, which are then transported to the protein storage vacuole (PSV) via the Golgi apparatus. Rab5 and its cognate activator guanine nucleotide exchange factor (GEF) are essential for the intracellular transport of proglutelin from the Golgi apparatus to the PSV. Results from previous studies showed that the double recessive type of glup4/rab5a and glup6/gef mutant accumulated much higher amounts of proglutelin than either parent line. The present study demonstrates that the double recessive type of glup4/rab5a and glup6/gef mutant showed not only elevated proglutelin levels and much larger paramural bodies but also reduced the number and size of PSVs, indicating a synergistic mutation effect. These observations led us to the hypothesis that other isoforms of Rab5 and GEF also participate in the intracellular transport of rice glutelin. A database search identified a novel guanine nucleotide exchange factor, Rab5-GEF2. Like GLUP6/GEF, Rab5-GEF2 was capable of activating Rab5a and two other Rab5 isoforms in in vitro GTP/GDP exchange assays. GEF proteins consist of the helical bundle (HB) domain at the N-terminus, Vps9 domain, and a C-terminal region. By the deletion analysis of GEFs, the HB domain was found essential for the activation of Rab5 proteins.

  8. Speciation and phytoavailability of cadmium in soil treated with cadmium-contaminated rice straw.

    Wang, Shuai; Huang, Dao-You; Zhu, Qi-Hong; Zhu, Han-Hua; Liu, Shou-Long; Luo, Zun-Chang; Cao, Xiao-Ling; Wang, Ji-Yu; Rao, Zhong-Xiu; Shen, Xin

    2015-02-01

    When grown on Cd-contaminated soil, rice typically accumulates considerable Cd in straw, and which may return to the soil after harvest. This work was undertaken to assess the pollution risk of Cd associated to the Cd-contaminated rice straw after incorporating into an uncontaminated soil. With the Cd-contaminated rice straw added at 0, 1, 2, 3, 4 and 5 % (w/w), an incubation experiment (28 days) with non-planting and a followed pot experiment sequent with two planting (rice and Chinese cabbage, transplanted after 28-day incubation) were carried out to investigate the changes of soil Cd speciation and phytoavailability. The results indicated that the Cd-contaminated rice straw addition significantly increased soil pH and dissolved organic carbon during the 28-day incubation. For the high availability of Cd in contaminated rice straw, diethylenetriaminepentaacetic acid (DTPA) extractable Cd significantly increased, and the percentages of acetic acid extractable and reducible Cd in soil significantly enhanced after the addition of Cd-contaminated rice straw. However, the Cd-contaminated rice straw addition inhibited the rice growth and induced the decrease of Cd in rice grain and straw by 12.8 to 70.2 % and 39.3 to 57.3 %, respectively, whereas the Cd contents increased by 13.9 to 84.1 % in Chinese cabbage that planted after rice harvest. In conclusion, Cd associated with Cd-contaminated rice straw was highly available after incorporating into the soil, and thus the Cd pollution risk via the Cd-contaminated rice straw incorporation should be evaluated in the Cd-contaminated paddy region.

  9. Loss‐of‐function mutation of rice SLAC7 decreases chloroplast stability and induces a photoprotection mechanism in rice

    Fan, Xiaolei; Wu, Jiemin; Chen, Taiyu; Tie, Weiwei; Chen, Hao; ZHOU, Fei; Lin, Yongjun

    2015-01-01

    Abstract Plants absorb sunlight to power the photochemical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mechanism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice (Oryza sativa L.) SLAC7 is a generally expressed membrane protein. Loss‐of‐function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf da...

  10. Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.

    Alamgir, Kabir Md; Hojo, Yuko; Christeller, John T; Fukumoto, Kaori; Isshiki, Ryutaro; Shinya, Tomonori; Baldwin, Ian T; Galis, Ivan

    2016-02-01

    Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants.

  11. Water relations of the tos1 tomato mutant at contrasting evaporative demand

    Albacete, Alfonso; Martínez-Ballesta, M. Carmen; Carvajal, Micaela; Autor Pérez-Alfocea, Francisco; Dodd, Ian C.; Romero-Aranda, Remedios

    2009-01-01

    The tos1 (tomato osmotically sensitive) mutant, isolated from an in vitro screen of root growth during osmotic stress, was less sensitive to exogenous ABA, but accumulated more ABA under osmotic stress than WT plants.

  12. In vitro assessment on the impact of soil arsenic in the eight rice varieties of West Bengal, India.

    Bhattacharya, Piyal; Samal, Alok C; Majumdar, Jayjit; Banerjee, Satabdi; Santra, Subhas C

    2013-11-15

    Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three high yielding, one hybrid and four local rice varieties to investigate the uptake, distribution and phytotoxicity of arsenic in rice plant. 5, 10, 20, 30 and 40 mg kg(-1) dry weights arsenic dosing was applied in pot soil and the results were compared with the control samples. All the studied high yielding and hybrid varieties (Ratna, IET 4094, IR 50 and Gangakaveri) were found to be higher accumulator of arsenic as compared to all but one local rice variety, Kerala Sundari. In these five rice varieties accumulation of arsenic in grain exceeded the WHO permissible limit (1.0 mg kg(-1)) at 20 mg kg(-1) arsenic dosing. Irrespective of variety, arsenic accumulation in different parts of rice plant was found to increase with increasing arsenic doses, but not at the same rate. A consistent negative correlation was established between soil arsenic and chlorophyll contents while carbohydrate accumulation depicted consistent positive correlation with increasing arsenic toxicity in rice plant.

  13. Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

    Hove-Jensen, Bjarne; Nygaard, Per

    1982-01-01

    , stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib....... Kinetic analysis of the mutant PRib-PP synthetase revealed an apparent Km for ATP and ribose 5-phosphate of 1.0 mM and 240 μM respectively, compared to 60 μM and 45 μM respectively for the wild-type enzyme. ADP, which inhibits the wild-type enzyme at a concentration of 0.5 mM ribose 5-phosphate...

  14. Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase

    Jochimsen, Bjarne; Hove-Jensen, Bjarne; Garber, Bruce B.;

    1985-01-01

    This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity. This strain was isolated in a purE deoD gpt purine auxotroph by a procedure designed to select guanosine......-utilizing mutants. Strain GP122 had roughly 15% of the PRPP synthetase activity and 25% of the PRPP pool of its parent strain. The mutant exhibited many of the predicted consequences of a decreased PRPP pool and a defective PRPP synthetase enzyme, including: poor growth on purine bases; decreased accumulation of 5...... phosphoribosyltransferase, enzymes involved in the pyrimidine de novo biosynthetic pathway; growth stimulation by PRPP-sparing compounds (e.g. guanosine, histidine); poor growth in low phosphate medium; and increased heat lability of the defective enzyme. This mutant strain also had increased levels of guanosine 5...

  15. Four rice seed cDNA clones belonging to the alpha-amylase/trypsin inhibitor gene family encode potential rice allergens.

    Alvarez, A M; Fukuhara, E; Nakase, M; Adachi, T; Aoki, N; Nakamura, R; Matsuda, T

    1995-07-01

    Four rice seed proteins encoded by cDNAs belonging to the alpha-amylase/trypsin inhibitor gene family were overexpressed as TrpE-fusion proteins in E. coli. The expressed rice proteins were detected by SDS-PAGE as major proteins in bacterial cell lysates. Western blot analyses showed that all the recombinant proteins were immunologically reactive to rabbit polyclonal antibodies and to a mouse monoclonal antibody (25B9) specific for a previously isolated rice allergen of 16 kDa. Some truncated proteins from deletion mutants of the cDNAs retained their reactivity to the specific antibodies. These results suggest that the cDNAs encode potential rice allergens and that some epitopes of the recombinant proteins are still immunoreactive when they are expressed as their fragments.

  16. Mutagenic effects of heavy ion irradiation on rice seeds

    Xu Xue [School of Agronomy, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036 (China); Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China); Liu Binmei; Zhang Lili [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China); Wu Yuejin, E-mail: yjwu@ipp.ac.cn [Key Laboratory of Ion Beam Bio-Engineering, Institute of Technical Biology and Agriculture Engineering, 350 Shushanhu Road, Hefei 230031 (China)

    2012-11-01

    Three varieties of rice seeds were subjected to irradiation using low-energy and medium-energy ions. The damage and mutations induced by the ions were examined. In addition, genetic analysis and gene mapping of spotted leaf (spl) mutants were performed. Low-energy ions had no significant influence on germination, survival or seedling height, except for the survival of Nipponbare. Medium-energy ions had a significant influence on germination and survival but had no significant effect on seedling height. In the low-energy group, among 60,000 M{sub 2} plants, 2823 putative morphological mutants were found, and the mutation frequency was approximately 4.71%. In the medium-energy group, 3132 putative morphological mutants were found, and the mutation frequency was approximately 5.22%. Five spl mutants (spl29-spl33) were obtained by ion irradiation, and the heredity of the spl mutants was stable. The characteristics of the spl mutants were found, by genetic analysis and preliminary mapping, to be controlled by a single recessive gene, and spl30 and spl33 were found to be new lesion-mimic mutants.

  17. Arsenic in rice agrosystems (water, soil and rice plants) in Guayas and Los Ríos provinces, Ecuador.

    Otero, X L; Tierra, W; Atiaga, O; Guanoluisa, D; Nunes, L M; Ferreira, T O; Ruales, J

    2016-12-15

    Geogenic arsenic (As) can accumulate and reach high concentrations in rice grains, thus representing a potential threat to human health. Ecuador is one of the main consumers of rice in South America. However, there is no information available about the concentrations of As in rice agrosystems, although some water bodies are known to contain high levels of the element. We carried out extensive sampling of water, soil, rice plants and commercial rice (obtained from local markets). Water samples were analysed to determine physico-chemical properties and concentrations of dissolved arsenic. Soil samples were analysed to determine total organic C, texture, total Fe and amorphous Fe oxyhydroxides (FeOx), total arsenic (tAs) and the bioavailable fraction (AsMe). The different plant parts were analysed separately to determine total (tAs), inorganic (iAs) and organic arsenic (oAs). Low concentrations of arsenic were found in samples of water (generally AsMe in flood water were negatively correlated with tAs in the plants. However, the concentrations of As in stems and leaves were linearly correlated with tAs in the soil and flood water. The relationship between tAs and arsenic in the grain fitted a logarithmic function, as did that between tAs in the grain and the stem. The findings seem to indicate that high concentrations of arsenic in the environment (soil or water) or in the rice stem do not necessarily imply accumulation of the element in the grain. The iAs form was dominant (>80%) in all parts of the rice plants.

  18. Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

    Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

    2015-07-01

    Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

  19. Study on Flavonoids in the Caryopsis of Indica Rice Rdh

    HAN Eei; DONG Bao-cheng; YANG Xiao-ji; HUANG Cheng-bin; WANG Xu-dong; WU Xian-jun

    2009-01-01

    To detect if there are phenolic flavonoids such as proanthocyanidins in Rdh, histochemistry assay toluidine blue O (TBO) staining and vanillin tests were performed. Rdh caryopsis transverse sections were stained by metachromatic stain TBO. It showed that there were a great deal of polyphenols in the pericarp and seed-coat tissues, and a little of them was in the cell wall of aleurone layers. The ovaries of Rdh and colorless rice were dealt with vanillin. It showed that all fertilized ovaries of Rdh were bright red regardless what degree the caryopsis maturity was, and all the ovaries of it before fertilization were not red after vanillin treatment. It suggested that every Rdh caryopsis had proanthocyanidins or its precursors, and fertilization was the premise of proanthocyanidins or its precursor synthesis. But colorless rice could not accumulate proanthocyanidins or its precursors. The pericarp, seed-coat and aleurone layer tissues of Rdh and colorless rice were anatomized and were dealt with vanillin. It was showed that three layers of Rdh were all bright red after treatment, revealing that they all had proanthocyanidins or its precursors, but colorless rice could not. It was suggested that polymerized proanthocyanindins were synthesized and accumulated in the pericarp of Rdh, and monomer-proanthocyanidins or leucoanthocyanidins were synthesized and accumulated in the seed-coat and the aleurone layer tissues.

  20. Rheological properties of rice-blackgram batter while replacing white rice with brown rice.

    Manickavasagan, Annamalai; Al-Marhubi, Insaaf Mohd; Dev, Satyanarayan

    2014-06-01

    Rice-blackgram batter is a raw material for many traditional convenience foods in Asia. Reformulation of traditional convenience food by replacing white rice with whole rice (brown rice) is a novel method to reduce the consumption of refined grain and increase the intake of whole grain in our diet. In this study, rheological properties of rice-blackgram batter was investigated while replacing white rice with brown rice at five levels (T1--0% replacement (control), T2--25% replacement, T3--50% replacement, T4--75% replacement, and T5--100% replacement). The shear stress versus shear rate plot indicates that the rice-blackgram batter exhibited non-Newtonian fluid behavior (shear thinning property) even after 100% replacement of white rice with brown rice. The rheological characteristics of rice-blackgram batters fitted reasonably well in Cassan (r2 = 0.8521-0.9856) and power law (r2 = 0.8042-0.9823) models. Brown rice repl