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Sample records for rice plants infested

  1. THE STEM BORER INFESTATION ON RICE CULTIVARS AT THREE PLANTING TIMES

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    Hendarsih Suharto

    2016-10-01

    Full Text Available Stem borer is the second important rice pest after rats in Indonesia. A field trial was conducted in Karawang, West Java in dry season of 2003 to study the effect of planting time on the stem borer infestation on seven rice cultivars. The rice cultivars tested were Fatmawati (new plant type cultivar, Gilirang (semi-new plant type cultivar, Maro and Intani 3 (hybrid rice cultivars, and IR72, Cilosari and IR62 (inbreed rice cultivars. The three planting times (PT were: (1 the early PT, 14 days before farmer’s PT, (2 the common PT, simultaneously with farmer’s PT, and (3 the late PT, 14 days after farmer’s PT. The trial was arranged in a split plot design with four replications. Planting time is the main plot and rice cultivar is the subplot. Fourteen-day old rice seedlings were transplanted at 25 cm x 25 cm planting distance in a 5 m x 6 m plot size. Species and fluctuation of rice stem borer were determined by using water traps containing four synthetic sex pheromone lures of rice stem borer species as attractant. Results showed that the dominant species of stem borer was yellow stem borer (Scirpophaga incertulas Wlk.. Degree of stem borer infestation depended upon the planting time. Stem borer infestation at the first planting time was higher (average 37.90% compared to those found at the second and third planting time, i.e. 0.65% and 0.54%, respectively. Rice yields of Fatmawati, Gilirang, Maro, Intani-3, and Cilosari cultivars correlated with the degree of stem borer infestation, but did not correlate with planting time. Cilosari cultivar showed the most tolerant under heavily stem borer infestation. The present study implies that adjustment of planting time is the most feasible effort to reduce stem borer infestation because none of the seven rice cultivars tested were able to minimize damage under heavily infestation of yellow stem borer.

  2. β-Glucosidase treatment and infestation by the rice brown planthopper Nilaparvata lugens elicit similar signaling pathways in rice plants

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    β-Glucosidase has been reported to induce the production of herbivore-induced plant volatiles.However,how it works remains unclear.Here,we investigated the levels of salicylic acid(SA),iasmonic acid (JA),ethylene,and H2O2,all of which are known signaling molecules that play important roles in induced plant defense in rice plants treated with β-glucosidase,and compared these to levels in plants infested by the rice brown planthopper Nilaparvata lugens(St(a)l).Results showed that wounding and treatment by β-glucosidase increased the levels of SA,ethylene,and H2O2.but not JA,in all plants compared to control plants.The signaling pathways activated by β-glucosidase treatment are similar to those activated by an infestation by N.lugens,although the magnitude and timing of the signals elicited by the two treatments are different.This may explain why both treatments have similar volatile profiles and are equally attractive to the parasitoid Anagrus nilaparvatae Pang et Wang.

  3. Induced defense responses in rice plants against small brown planthopper infestation

    Institute of Scientific and Technical Information of China (English)

    Canxing; Duan; Jiaojiao; Yu; Jianyu; Bai; Zhendong; Zhu; Xiaoming; Wang

    2014-01-01

    The small brown planthopper(SBPH), Laodelphax striatellus Fallén(Homoptera: Delphacidae), is a serious pest of rice(Oryza sativa L.) in China. To understand the mechanisms of rice resistance to SBPH, defense response genes and related defense enzymes were examined in resistant and susceptible rice varieties in response to SBPH infestation. The salicylic acid(SA) synthesis-related genes phenylalanine ammonia-lyase(PAL), NPR1, EDS1 and PAD4 were induced rapidly and to a much higher level in the resistant variety Kasalath than in the susceptible cultivar Wuyujing 3 in response to SBPH infestation. The expression level of PAL in the Kasalath rice at 12 h post-infestation(hpi) increased 7.52-fold compared with the un-infested control, and the expression level in Kasalath was 49.63, 87.18, 57.36 and 75.06 times greater than that in Wuyujing 3 at 24, 36, 48 and 72 hpi, respectively. However, the transcriptional levels of the jasmonic acid(JA) synthesis-related genes LOX and AOS2 in resistant Kasalath were significantly lower than in susceptible Wuyujing 3 at 24, 36, 48 and 72 hpi. The activities of the defense enzymes PAL, peroxidase(POD), and polyphenol oxidase(PPO) increased remarkably in Kasalath in response to SBPH infestation, and were closely correlated with the PAL gene transcript level. Our results indicated that the SA signaling pathway was activated in the resistant Kasalath rice variety in response to SBPH infestation and that the gene PAL played a considerable role in the resistance to SBPH.

  4. Induced defense responses in rice plants against small brown planthopper infestation

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    Canxing Duan

    2014-02-01

    Full Text Available The small brown planthopper (SBPH, Laodelphax striatellus Fallén (Homoptera: Delphacidae, is a serious pest of rice (Oryza sativa L. in China. To understand the mechanisms of rice resistance to SBPH, defense response genes and related defense enzymes were examined in resistant and susceptible rice varieties in response to SBPH infestation. The salicylic acid (SA synthesis-related genes phenylalanine ammonia-lyase (PAL, NPR1, EDS1 and PAD4 were induced rapidly and to a much higher level in the resistant variety Kasalath than in the susceptible cultivar Wuyujing 3 in response to SBPH infestation. The expression level of PAL in the Kasalath rice at 12 h post-infestation (hpi increased 7.52-fold compared with the un-infested control, and the expression level in Kasalath was 49.63, 87.18, 57.36 and 75.06 times greater than that in Wuyujing 3 at 24, 36, 48 and 72 hpi, respectively. However, the transcriptional levels of the jasmonic acid (JA synthesis-related genes LOX and AOS2 in resistant Kasalath were significantly lower than in susceptible Wuyujing 3 at 24, 36, 48 and 72 hpi. The activities of the defense enzymes PAL, peroxidase (POD, and polyphenol oxidase (PPO increased remarkably in Kasalath in response to SBPH infestation, and were closely correlated with the PAL gene transcript level. Our results indicated that the SA signaling pathway was activated in the resistant Kasalath rice variety in response to SBPH infestation and that the gene PAL played a considerable role in the resistance to SBPH.

  5. Impact of volunteer rice infestation on yield and grain quality of rice.

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    Singh, Vijay; Burgos, Nilda R; Singh, Shilpa; Gealy, David R; Gbur, Edward E; Caicedo, Ana L

    2017-03-01

    Volunteer rice (Oryza sativa L.) grains may differ in physicochemical traits from cultivated rice, which may reduce the quality of harvested rice grain. To evaluate the effect of volunteer rice on cultivated rice, fields were surveyed in Arkansas in 2012. Cropping history that included hybrid cultivars in the previous two years (2010 and 2011) had higher volunteer rice infestation (20%) compared with fields planted previously with inbred rice (5.5%). The total grain yield of rice was reduced by 0.4% for every 1% increase in volunteer rice density. The grain quality did not change in fields planted with the same cultivar for three years. Volunteer rice density of at least 7.6% negatively impacted the head rice and when infestation reached 17.7%, it also reduced the rice grain yield. The protein and amylose contents of rice were not affected until volunteer rice infestation exceeded 30%. Crop rotation systems that include hybrid rice are expected to have higher volunteer rice infestation than systems without hybrid rice. It is predicted that, at 8% infestation, volunteer rice will start to impact head rice yield and will reduce total yield at 18% infestation. It could alter the chemical quality of rice grain at >30% infestation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Weed communities of rain-fed lowland rice vary with infestation by Rhamphicarpa fistulosa

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    Houngbédji, Tossimidé; Dessaint, Fabrice; Nicolardot, Bernard; Shykoff, Jacqui A.; Gibot-Leclerc, Stéphanie

    2016-11-01

    The facultative hemiparasitic plant Rhamphicarpa fistulosa (Orobanchaceae) thrives in seasonally wet soils in sub-Saharan Africa, mainly in marginal lowland rice growing environments where weeds are already a major constraint for rice production. Because lowland rice production is increasing in tropical Africa, it is important to ascertain the influence of R. fistulosa on weed plant communities in these rice-growing habitats. We investigated weed plant community richness and composition at four different levels of R. fistulosa infestation across two years of surveys from lowland rice fields in northern Togo (West Africa). Despite a lack of significant differences in community richness among sites with different R. fistulosa infestation levels, there were significant differences in community composition, both when estimated from presence-absence data and from relative abundance data, after controlling statistically for geographic proximity among sites. Rhamphicarpa fistulosa infestation, therefore, may influence the competitive balance between rice and its weeds and shape weed community structure. However, experimental studies are required to elucidate the weed host range of R. fistulosa and the direct and indirect effects of this hemiparasite in rice fields in order to predict its net impact on rice and its weed species.

  7. Omics-Based Comparative Transcriptional Profiling of Two Contrasting Rice Genotypes during Early Infestation by Small Brown Planthopper

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    Weilin Zhang

    2015-12-01

    Full Text Available The small brown planthopper (SBPH is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this study, an omics-based comparative transcriptional profiling of two contrasting rice genotypes, an SBPH-resistant and an SBPH-susceptible rice line, was assessed for rice individual metabolic pathways responsive to SBPH infestation. When exposed to SBPH, 166 metabolic pathways were differentially regulated; of these, more than one-third of metabolic pathways displayed similar change patterns between these two contrasting rice genotypes; the difference of change pattern between these two contrasting rice genotypes mostly lies in biosynthetic pathways and the obvious difference of change pattern lies in energy metabolism pathways. Combining the Pathway Tools Omics Viewer with the web tool Venn, 21 and 6 metabolic pathways which potentially associated with SBPH resistance and susceptibility, respectively were identified. This study presents an omics-based comparative transcriptional profiling of SBPH-resistant and SBPH-susceptible rice plants during early infestation by SBPH, which will be very informative in studying rice-insect interaction. The results will provide insight into how rice plants respond to early infestation by SBPH from the biochemical pathways perspective.

  8. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in noncrop grasses of Gulf Coast rice agroecosystems.

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    Beuzelin, J M; Mészáros, A; Reagan, T E; Wilson, L T; Way, M O; Blouin, D C; Showler, A T

    2011-10-01

    Infestations of two stem borers, Eoreuma loftini (Dyar) and Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were compared in noncrop grasses adjacent to rice (Oryza sativa L.) fields. Three farms in the Texas rice Gulf Coast production area were surveyed every 6-8 wk between 2007 and 2009 using quadrat sampling along transects. Although D. saccharalis densities were relatively low, E. loftini average densities ranged from 0.3 to 5.7 immatures per m(2) throughout the 2-yr period. Early annual grasses including ryegrass, Lolium spp., and brome, Bromus spp., were infested during the spring, whereas the perennial johnsongrass, Sorghum halepense (L.) Pers., and Vasey's grass, Paspalum urvillei Steud., were infested throughout the year. Johnsongrass was the most prevalent host (41-78% relative abundance), but Vasey's grass (13-40% relative abundance) harbored as much as 62% of the recovered E. loftini immatures (during the winter). Young rice in newly planted fields did not host stem borers before June. April sampling in fallow rice fields showed that any available live grass material, volunteer rice or weed, can serve as a host during the spring. Our study suggests that noncrop grasses are year-round sources of E. loftini in Texas rice agroecosystems and may increase pest populations.

  9. Genome-wide transcriptional changes and defence-related chemical profiling of rice in response to infestation by the rice striped stem borer Chilo suppressalis.

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    Zhou, Guoxin; Wang, Xia; Yan, Feng; Wang, Xia; Li, Ran; Cheng, Jiaan; Lou, Yonggen

    2011-09-01

    How rice defends itself against pathogen infection is well documented, but little is known about how it defends itself against herbivore attack. We measured changes in the transcriptome and chemical profile of rice when the plant is infested by the striped stem borer (SSB) Chilo suppressalis. Infestation by SSBs resulted in changes in the expression levels of 4545 rice genes; this number accounts for about 8% of the genome and is made up of 18 functional groups with broad functions. The largest group comprised genes involved in metabolism, followed by cellular transport, transcription and cellular signaling. Infestation by SSBs modulated many genes responsible for the biosynthesis of plant hormones and plant signaling. Jasmonic acid (JA), salicylic acid (SA) and ethylene were the major hormones that shaped the SSB-induced defence responses of rice. Many secondary signal transduction components, such as those involved in Ca²⁺ signaling and G-protein signaling, receptor and non-receptor protein kinases, and transcription factors were involved in the SSB-induced responses of rice. Photosynthesis and ATP synthesis from photophosphorylation were restricted by SSB feeding. In addition, SSB infestation induced the accumulation of defence compounds, including trypsin proteinase inhibitors (TrypPIs) and volatile organic compounds. These results demonstrate that SSB-induced defences required rice to reconfigure a wide variety of its metabolic, physiological and biochemical processes.

  10. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in noncrop grasses of Gulf Coast rice agroecosystems

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    Infestations of two stem borers, the Mexican rice borer, Eoreuma loftini (Dyar) and the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were compared in non-crop grasses adjacent to rice, Oryza sativa L., fields. Three farms in the Texas Gulf Coast rice production area were sur...

  11. Ecological Fitness of Non-vector Planthopper Sogatella furcifera on Rice Plants Infected with Rice Black Streaked Dwarf Virus

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-chan; XU Hong-xing; ZHENG Xu-song; YANG Ya-jun; GAO Guang-chun; PAN Jian-hong; LU Zhong-xian

    2012-01-01

    We evaluated the effects of rice black streak dwarf virus (RBSDV)-infested rice plants on the ecological parameters and its relevant defensive and detoxification enzymes of white-backed planthopper (WBPH) in laboratory for exploring the relationship between RBSDV and the non-vector planthopper.The results showed that nymph survival rate,female adult weight and fecundity,and egg hatchability of WBPH fed on RBSDV-infested rice plants did not markedly differ from those on healthy plants,whereas the female adult longevity and egg duration significantly shortened on diseased plants.Furthermore,significantly higher activities of defensive enzymes (dismutase,catalase and peroxidase) and detoxification enzymes (acetylcholinesterase,carboxylesterase and glutathione S-transferase) were found in WBPH adults fed on infected plants.Results implied that infestation by RBSDV increased the ecological fitness of non-vector planlhopper population.

  12. Comparing gene expression profiles between Bt and non-Bt rice in response to brown planthopper infestation

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    Fang eWang

    2015-12-01

    Full Text Available Bt proteins are the most widely used insecticidal proteins in transgenic crops for improving insect resistance. We previously observed longer nymphal developmental duration and lower fecundity in brown planthopper (BPH fed on Bt rice line KMD2, although Bt insecticidal protein Cry1Ab could rarely concentrate in this non-target rice pest. In the present study, we performed microarray analysis in an effort to detect Bt-independent variation, which might render Bt rice more defensive and/or less nutritious to BPH. We detected 3,834 and 3,273 differentially expressed probe-sets in response to BPH infestation in non-Bt parent Xiushui 11 and Bt rice KMD2, respectively, only 439 of which showed significant differences in expression between rice lines. Our analysis revealed a shift from growth to defense responses in response to BPH infestation, which was also detected in many other studies of plants suffering biotic and abiotic stresses. Chlorophyll biosynthesis and basic metabolism pathways were inhibited in response to infestation. IAA and GA levels decreased as a result of the repression of biosynthesis-related genes or the induction of inactivation-related genes. In accordance with these observations, a number of IAA-, GA-, BR-signaling genes were downregulated in response to BPH. Thus, the growth of rice plants under BPH attack was reduced and defense related hormone signaling like JA, SA and ET were activated. In addition, growth-related hormone signaling pathways, such as GA, BR and auxin signaling pathways, as well as ABA, were also found to be involved in BPH-induced defense. On the other side, 51 probe-sets (represented 50 genes that most likely contribute to the impact of Bt rice on BPH were identified, including three early nodulin genes, four lipid metabolic genes, 14 stress response genes, three TF genes and genes with other functions. Two transcription factor genes, bHLH and MYB, together with lipid transfer protein genes LTPL65 and

  13. Increasing rice plant growth by Trichoderma sp.

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    Doni, Febri; Isahak, Anizan; Zain, Che Radziah Che Mohd; Sulaiman, Norela; Fathurahman, F.; Zain, Wan Nur Syazana Wan Mohd.; Kadhimi, Ahsan A.; Alhasnawi, Arshad Naji; Anhar, Azwir; Yusoff, Wan Mohtar Wan

    2016-11-01

    Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

  14. Strigolactone and root infestation by parasitic plants.

    NARCIS (Netherlands)

    Cardoso, C.; Ruyter-Spira, C.P.; Bouwmeester, H.J.

    2011-01-01

    Strigolactones are signaling molecules that play a role in host recognition by parasitic plants of the Striga, Orobanche and Phelipanche genera which are among the most detrimental weeds in agriculture. The same class of molecules is also involved in the establishment of the symbiosis of plants with

  15. SSR分子标记丰富向日葵(HelianthusannuusL.)遗传图谱的研究%Differences in Ecological Fitness Between Bt Transgenic Rice and Conventional Rice Under Insect-infestation Pressures

    Institute of Scientific and Technical Information of China (English)

    黄先群; Genzbitelle L.; Fabre F.; Saraffi A.

    2012-01-01

    [目的]提高向日葵遗传图谱的密度和实用性。[方法]以123个来源于PAC.2和RHA-266杂交的F8代重组自交系(RILs)群体为材料,利用简单序列重复(Simplesequencerepeat,SSR)标记,采用MAPMARKER软件对向口葵遗传图谱进行标注。从300对SSR引物中筛选出51对有多态性的引物对(RILs)群体进行扫描。[结果]有19对引物无多态性或条带不清晰,32对引物表现多态性;共检测到35个多态性位点,分布在图谱的15条连锁群上。标记后的图谱总长度为2914.5cM,比原来的图谱增长7.5cM。标记间平均距离由9.0cM缩短为8.1cM。【结论】为进一步的向日葵遗传图谱整合和分子标记辅助选择提供参号。%In order to investigate the possibility and efficiency of exogenous gene spread in nature and potential ecological risk of transgenic rice, as well as analyze the effect of exogenous Bt gene insertion on ecological fitness of transgenic rice plants, a experiment was carried out with three insect-resistant Bt transgenic rice cultivars Bt63, R1 and R2 and one conventional rice line 11-838 as experimental materials, the insect-resistant transgenic and non-transgenic rice plants were inter- cropped pair-wisely under high and low insect-infestation pressures, and the vegeta- tive growth, seed-setting and the resistance to rice stem borers were compared be- tween transgenic and non-transgenic lines. According to the experimental results, both the tiller number and fresh weight of Bt transgenic rice plants under low insect- infestation pressure showed no significant differences compared with the control, but the plant height, spike length and spike weight were all lower than those of non- transgenic rice plant, and Bt63 and R2 were significantly different compared with the control. On the contrary, under high insect-infestation pressure, the tiller number, spike length and spike weight of three Bt transgenic rice cultivars were

  16. Intercropping System for Protection the Potato Plant from Insect Infestation

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    Aziza Sharaby

    2015-06-01

    Full Text Available The use of intercropping system provides an option for insect control for organic farmers that are limited in their chemical use. Additionally, intercropping systems can be attractive to conventional growers as a cost-effective insect control solution. A study was carried out for two seasons 2011-2012 and 2012-2013 to evaluate the effect of intercropping of potato (Solanum tuberosum L. with onion (Allium cepa L. on whitefly (Bemicia tabasi Gennadius and aphids’ Myzus persicae Sulz. and Aphis gossypii Glover infestation in potato fields. Results indicated that intercropping significantly reduced potato plant infestation with whitefly by 42.7, 51.3% while it was 62.69% reduction with aphids during the two successive winter seasons than when potato plants were cultivated alone. Therefore, intercropping could be recommended as a protection method of reducing pest population in the fields.

  17. In situ localization of proteinase inhibitor mRNA in rice plant challenged by brown planthopper

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Proteinase inhibitor (PI) mRNA was localized by in situ hybridization in tissue sections of root, stem and leaf of the resistant rice (B5) plant fed by brown planthopper nymphs. In the rice material without BPH feeding, PI gene was expressed in the root, stem and leaf, while the abundance of PI mRNA was low. In the rice material fed by BPH, PI gene was expressed substantially in the parenchyma of rice stem and leaf, but weakly in the root. The results indicated that the PI gene was up-regulated in the rice plant challenged by brown planthopper. For the first time, we reported the expression changes of proteinase inhibitor gene in plant which was infested by a piercing/sucking insect.

  18. Dissipation of pencycuron in rice plant

    Institute of Scientific and Technical Information of China (English)

    PAL R.; CHAKRABARTI K.; CHAKRABORTY A.; CHOWDHURY A.

    2005-01-01

    Pencycuron is a non-systemic protective fungicide for controlling sheath blight of rice. However, information on the fate of pencycuron in rice plant is lacking. The degradation of pencycuron in waterlogged tropic rice field was investigated.Pencycuron was applied at recommended field dose (187.5 g a.i./ha) and double recommended dose to cropped plots for three consecutive years. Pencycuron was rapidly degraded in rice plant at all doses of pencycuron application with first order half-lives of 1.57~2.77 d. The study revealed that pencycuron is safe from the human and environmental contamination point of view.

  19. An implicit approach to model plant infestation by insect pests.

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    Lopes, Christelle; Spataro, Thierry; Doursat, Christophe; Lapchin, Laurent; Arditi, Roger

    2007-09-07

    Various spatial approaches were developed to study the effect of spatial heterogeneities on population dynamics. We present in this paper a flux-based model to describe an aphid-parasitoid system in a closed and spatially structured environment, i.e. a greenhouse. Derived from previous work and adapted to host-parasitoid interactions, our model represents the level of plant infestation as a continuous variable corresponding to the number of plants bearing a given density of pests at a given time. The variation of this variable is described by a partial differential equation. It is coupled to an ordinary differential equation and a delay-differential equation that describe the parasitized host population and the parasitoid population, respectively. We have applied our approach to the pest Aphis gossypii and to one of its parasitoids, Lysiphlebus testaceipes, in a melon greenhouse. Numerical simulations showed that, regardless of the number and distribution of hosts in the greenhouse, the aphid population is slightly larger if parasitoids display a type III rather than a type II functional response. However, the population dynamics depend on the initial distribution of hosts and the initial density of parasitoids released, which is interesting for biological control strategies. Sensitivity analysis showed that the delay in the parasitoid equation and the growth rate of the pest population are crucial parameters for predicting the dynamics. We demonstrate here that such a flux-based approach generates relevant predictions with a more synthetic formalism than a common plant-by-plant model. We also explain how this approach can be better adapted to test different management strategies and to manage crops of several greenhouses.

  20. Oviposition behavior of the wheat stem sawfly when encountering plants infested with cryptic conspecifics.

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    Buteler, Micaela; Weaver, David K; Peterson, Robert K D

    2009-12-01

    Insect herbivores typically oviposit on the most suitable hosts, but choices can be modulated by detection of potential competition among conspecifics, especially when eggs are deposited cryptically. Larvae of the wheat stem sawfly, Cephus cinctus Norton, developing within an already infested stem, experience elevated risk when only one will survive because of cannibalism. To increase our understanding of host selection when the choices made by females can lead to severe intraspecific competition, females were presented with either uninfested wheat plants or with plants previously exposed to other females in laboratory choice tests. The oviposition behavior of this insect was described by recording the behavioral sequences that lead to and follow the insertion of the ovipositor in both previously infested and uninfested stems. No significant differences were found in frequencies of specific behaviors or behavioral transitions associated with oviposition. In choice tests, there was no difference in the numbers of eggs laid in infested and uninfested plants. Taller plants received more eggs, irrespective of infestation. Females neither preferred nor avoided previously infested hosts. Other characteristics of the host, such as stem height, may be more important in determining suitability for oviposition. These findings support the use of management tactics relying on the manipulation of oviposition behavior, such as trap cropping. Given that there is no evidence for response to previously infested hosts, the infested plants in a trap crop would remain as suitable as they were when uninfested, which could also lead to an increase in mortality caused by intraspecific competition.

  1. Effect of Nitrogen on Weed Infestation and Performance of Boro Rice Under Two Selected Herbicides

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    MM Morshed, MN Bari, QA Khaliq, MS Alam

    2015-12-01

    Full Text Available A field experiment was conducted at the experimental farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU, Salna, Gazipur from November 2013 to May 2014 to determine the effect of nitrogen and herbicide on weed infestation and performance of Boro rice (cv. BRRIdhan28. Five nitrogen doses i.e. 0 , 50.6 , 101.2 , 151.8 and 202.4 kg ha-1 under selected pre-emergence and post-emergence herbicides along with one weed free and control (unweeded treatment were imposed in the experiment. Nine weed species was found to dominate in the experimental plots where Scirpus maritimus L. showed the maximum visual abundance (58% followed by Leersia hexandra sw., Paspalam distichum L. and Fimbristylis miliacea L. Post-emergence herbicide contributed to higher control efficiency than that in pre-emergence herbicide. Post-emergence herbicide without receiving nitrogen showed the highest weed control efficiency (97.39 at 60 days after transplanting. Treatment receiving N @ 200.4 kg ha-1 under post-emergence herbicide showed the highest number of tiller per hill (13.00, total dry matter (1568.6 g m-2, panicles per hill (10.60, filled grains per panicle (125.20 and grain yield (6.46 t/ha. N-dose 151.8 kg ha-1 under postemergence herbicide contributed to the second highest grain yield (6.41 t ha-1 with the highest benefit cost ratio of 1.60 but 50.6 kg N ha-1 under post-emergence herbicide showed the maximum Nitrogen use efficiency of 0.49. The study revealed that nitrogen dose up to 151.8 kg ha-1 might be increased above the recommended dose under coverage of a suitable post-emergence herbicide for profitable rice production.

  2. Using SPOT-5 images in rice farming for detecting BPH (Brown Plant Hopper)

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    Ghobadifar, F.; Wayayok, A.; Shattri, M.; Shafri, H.

    2014-06-01

    Infestation of rice plant-hopper such as Brown Plant Hopper (BPH) (Nilaparvata lugens) is one of the most notable risk in rice yield in tropical areas especially in Asia. In order to use visible and infrared images to detect stress in rice production caused by BPH infestation, several remote sensing techniques have been developed. Initial recognition of pest infestation by means of remote sensing will spreads, for precision farming practice. To address this issue, detection of sheath blight in rice farming was examined by using SPOT-5 images. Specific image indices such as Normalized decrease food production costs, limit environmental hazards, and enhance natural pest control before the problem Normalized Difference Vegetation Index (NDVI), Standard difference indices (SDI) and Ratio Vegetation Index (RVI) were used for analyses using ENVI 4.8 and SPSS software. Results showed that all the indices to recognize infected plants are significant at α = 0.01. Examination of the association between the disease indices indicated that band 3 (near infrared) and band 4 (mid infrared) have a relatively high correlation. The selected indices declared better association for detecting healthy plants from diseased ones. Consequently, these sorts of indices especially NDVI could be valued as indicators for developing techniques for detecting the sheath blight of rice by using remote sensing. This infers that they are useful for crop disease detection but the spectral resolution is probably not sufficient to distinguish plants with light infections (low severity level). Using the index as an indicator can clarify the threshold for zoning the outbreaks. Quick assessment information is very useful in precision farming to practice site specific management such as pesticide application.

  3. Insect stings to change gear for healthy plant: Improving maize drought tolerance by whitefly infestation.

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    Park, Yong-Soon; Ryu, Choong-Min

    2016-05-03

    Since plants first appeared about 1.1 billion years ago, they have been faced with biotic and abiotic stresses in their environment. To overcome these stresses, plants developed defense strategies. Accumulating evidence suggests that the whitefly [Bemisia tabaci (Genn.)] affects the regulation of plant defenses and physiology. A recent study demonstrates that aboveground whitefly infestation positively modulates root biomass and anthocyanin pigmentation on brace roots of maize plants (Zea mays L.). In agreement with these observations, indole-3-acetic acid (IAA) and jasmonic acid (JA) contents and the expression of IAA- and JA-related genes are higher in whitefly-infested maize plants than in non-infected control plants. Interestingly, the fresh weight of whitefly-infested maize plants is approximately 20% higher than in non-infected control plants under water stress conditions. Further investigation has revealed that hydrogen peroxide (H2O2) accumulates in whitefly-infested maize plants after water stoppage. Taken together, these results suggest that activation of phytohormones- (i.e., IAA and JA) and H2O2-mediated maize signaling pathways triggered by aboveground whitefly infestation promotes drought resistance. They also provide an insight into how inter-kingdom interactions can improve drought tolerance in plants.

  4. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    Science.gov (United States)

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  5. Olfactory response of predatory Macrolophus caliginosus Wagner (Heteroptera: Miridae) to the odours host plant infested by Bemisia tabaci

    Science.gov (United States)

    Saad, Khalid A.; Roff, M. N. Mohamad; Salam, Mansour; Hanifah Mohd, Y.; Idris, A. B.

    2014-09-01

    Plant infested with herbivores, release volatile that can be used by natural enemies to locate their herbivorous prey. Laboratory studies were carried out to determine the olfactory responses of predator Macrolophus caliginosus Wagner (Heteroptera: Miridae), to chili plant infected with eggs, nymphs of Bemisia tabaci, using Y-tube olfactometer. The results shown that predator, M. caliginosus has ability to discriminate between non-infested and infested plant by B. tabaci. Moreover, the predator preferred plants with nymphs over plants with eggs. This suggested that M. caliginous uses whitefly-induced volatile as reliable indicators to distinguish between infested chili plants by nymphs, eggs and non-infested plants. These results enhance our understanding of the olfactory cues that guide foraging by M. caliginosus to plant with and without Bemisia tabaci.

  6. Prevalence of Deg Nala disease in eastern India and its reproduction in buffaloes by feeding Fusarium oxysporum infested rice straw

    Institute of Scientific and Technical Information of China (English)

    P Dandapat; PK Nanda; S Bandyopadhyay; Anmol Kaushal; A Sikdar

    2011-01-01

    Objective: To undertake a study on prevalence of Deg Nala disease in eastern states of India and to reproduce the disease in buffaloes by the Fusarium spp., isolated from the affected region.Methods:During this investigation, a survey was conducted covering four states of eastern region to identify the Deg Nala cases as well as to isolate and characterize the causative agent(s). An experimental study was carried out to reproduce the disease in healthy male buffaloes (2-3 years age) by randomly dividing them into five groups (four in each group). Each individual group was fed with rice straw artificially infested with either of the two representative isolates ofFusarium oxysporum (F. oxysporum) (F01, F02) or representative reference strains of Fusarium equiseti (F. equiseti) (ITCCF-2470) and Fusarium moniliforme (F. moniliforme) (ITCCF-4821) for 30 days, whereas the control group was fed with normal rice straw only. Results: A total of 658 Deg Nala cases were recorded and 12 Fusarium isolates were identified from the mouldy rice straw collected from these affected areas. The characterization of the isolates revealed three species viz., F. oxysporum, F. equiseti and F. moniliforme, among which F. oxysporum was predominant. The disease was artificially reproduced in three buffaloes in F01 group and one in F02 group within 20-23 days by feeding F. oxysporum infested rice straw which resembled the clinical symptoms and gross lesions of natural Deg Nala cases. Conclusions: The field investigation and laboratory studies, including experimental production of Deg Nala disease suggest the possible involvement of mycotoxins. However, further investigations needs to be done to understand nature of the toxic factors involved in production of the Deg Nala disease.

  7. Variation in composition of predator-attracting allelochemicals emitted by herbivore-infested plants: relative influence of plant and herbivore.

    NARCIS (Netherlands)

    Takabayashi, J.; Dicke, M.; Posthumus, M.A.

    1991-01-01

    During foraging, natural enemies of herbivores may employ volatile allelochemicals that originate from an interaction of the herbivore and its host plant. The composition of allelochemical blends emitted by herbivore-infested plants is known to be affected by both the herbivore and the plant. Our

  8. Cross-kingdom effects of plant-plant signaling via volatile organic compounds emitted by tomato (Solanum lycopersicum) plants infested by the greenhouse whitefly (Trialeurodes vaporariorum).

    Science.gov (United States)

    Ángeles López, Yesenia Ithaí; Martínez-Gallardo, Norma Angélica; Ramírez-Romero, Ricardo; López, Mercedes G; Sánchez-Hernández, Carla; Délano-Frier, John Paul

    2012-11-01

    Volatile organic compounds (VOCs) emitted from plants in response to insect infestation can function as signals for the attraction of predatory/parasitic insects and/or repulsion of herbivores. VOCs also may play a role in intra- and inter-plant communication. In this work, the kinetics and composition of VOC emissions produced by tomato (Solanum lycopersicum) plants infested with the greenhouse whitefly Trialeurodes vaporariorum was determined within a 14 days period. The VOC emission profiles varied concomitantly with the duration of whitefly infestation. A total of 36 different VOCs were detected during the experiment, 26 of which could be identified: 23 terpenoids, plus decanal, decane, and methyl salicylate (MeSA). Many VOCs were emitted exclusively by infested plants, including MeSA and 10 terpenoids. In general, individual VOC emissions increased as the infestation progressed, particularly at 7 days post-infestation (dpi). Additional tunnel experiments showed that a 3 days exposure to VOC emissions from whitefly-infested plants significantly reduced infection by a biotrophic bacterial pathogen. Infection of VOC-exposed plants induced the expression of a likely tomato homolog of a methyl salicylate esterase gene, which preceded the expression of pathogenesis-related protein genes. This expression pattern correlated with reduced susceptibility in VOC-exposed plants. The observed cross-kingdom effect of plant-plant signaling via VOCs probably represents a generalized defensive response that contributes to increased plant fitness, considering that resistance responses to whiteflies and biotrophic bacterial pathogens in tomato share many common elements.

  9. Infestation of Raoiella indica Hirst (Trombidiformes: Tenuipalpidae) on Host Plants of High Socio-Economic Importance for Tropical America.

    Science.gov (United States)

    Otero-Colina, G; González-Gómez, R; Martínez-Bolaños, L; Otero-Prevost, L G; López-Buenfil, J A; Escobedo-Graciamedrano, R M

    2016-06-01

    The mite Raoiella indica Hirst was recently introduced into America, where it has shown amazing ability to disseminate and broaden its range of hosts. An experiment was conducted in Cancún, Mexico, to determine infestation levels of this mite on plants recorded as hosts: coconut palm (Cocos nucifera) of cultivars Pacific Tall and Malayan Dwarf, oil palm (Elaeis guineensis) hybrids Deli x Ghana and Deli x Nigeria, Dwarf Giant banana (Musa acuminata, AAA subgroup Cavendish), Horn plantain (M. acuminata x Musa balbisiana, AAB subgroup Plantain), lobster claw (Heliconia bihai), and red ginger (Alpinia purpurata). Nursery plants of these host species or cultivars were artificially infested with R. indica in February 2011. In the four replications of 10 plants, each plant was infested with 200 R. indica specimens, and the numbers of infesting mites were recorded for 6 months. A maximum of 18,000 specimens per plant were observed on coconut Pacific Tall and Malayan Dwarf, followed by lobster claw, with a maximum of 1000 specimens per plant. Infestations were minimal for the remaining plants. Mite numbers on all plants declined naturally during the rainy season. All plant materials sustained overlapping mite generations, indicating that they are true hosts. Complementarily, infestation level was determined in backyard bananas and plantains. Correlations of infestation with plant height, distance from coconuts, and exposure to direct sunlight were estimated. Both bananas and plantains were infested by R. indica even when situated far from infested coconut palms. A Spearman correlation was found between infestation and plant height, although it was significant only for Silk plantain.

  10. Direct and Indirect Impacts of Infestation of Tomato Plant by Myzus persicae (Hemiptera: Aphididae) on Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Tan, Xiao-Ling; Wang, Su; Ridsdill-Smith, James; Liu, Tong-Xian

    2014-01-01

    The impacts of infestation by the green peach aphid (Myzus persicae) on sweetpotato whitefly (Bemisia tabaci) settling on tomato were determined in seven separate experiments with whole plants and with detached leaves through manipulation of four factors: durations of aphid infestation, density of aphids, intervals between aphid removal after different durations of infestation and the time of whitefly release, and leaf positions on the plants. The results demonstrated that B. tabaci preferred to settle on the plant leaves that had not been infested by aphids when they had a choice. The plant leaves on which aphids were still present (direct effect) had fewer whiteflies than those previously infested by aphids (indirect effect). The whiteflies were able to settle on the plant which aphids had previously infested, and also could settle on leaves with aphids if no uninfested plants were available. Tests of direct factors revealed that duration of aphid infestation had a stronger effect on whitefly landing preference than aphid density; whitefly preference was the least when 20 aphids fed on the leaves for 72 h. Tests of indirect effects revealed that the major factor that affected whitefly preference for a host plant was the interval between the time of aphid removal after infestation and the time of whitefly release. The importance of the four factors that affected the induced plant defense against whiteflies can be arranged in the following order: time intervals between aphid removal and whitefly release > durations of aphid infestation > density of aphids > leaf positions on the plants. In conclusion, the density of aphid infestation and time for which they were feeding influenced the production of induced compounds by tomatoes, the whitefly responses to the plants, and reduced interspecific competition. PMID:24710393

  11. Hybrid sterility in plant: stories from rice.

    Science.gov (United States)

    Ouyang, Yidan; Liu, Yao-Guang; Zhang, Qifa

    2010-04-01

    Hybrid sterility is the most common form of postzygotic reproductive isolation in plants. The best-known example is perhaps the hybrid sterility between indica and japonica subspecies of Asian cultivated rice (Oryza sativa L.). Major progress has been reported recently in rice in identifying and cloning hybrid sterility genes at two loci regulating female and male fertility, respectively. Genetic analyses and molecular characterization of these genes, together with the results from other model organisms especially Drosophila, have advanced the understanding of the processes underlying reproductive isolation and speciation. These findings also have significant implications for crop genetic improvement, by providing the feasibility and strategies for overcoming intersubspecific hybrid sterility thus allowing the development of intersubspecific hybrids.

  12. Characteristics of Rice Plant with Heavy Panicle

    Institute of Scientific and Technical Information of China (English)

    MA Jun; MA Wen-bo; MING Dong-feng; YANG Shi-ming; ZHU Qing-sen

    2006-01-01

    Using 15 indica rice varieties with different panicle weight, some ideal plant type characteristics in heavy panicle type of hybrid rice (HPT) and their relation to yield and its components were studied. Results showed that the leaf area index (LAI) of the HPT varieties was lower than that of medium panicle type (MPT) and light panicle type (LPT) varieties, but its decreasing rate of LAI and efficient LAI after heading was slower and had much higher percentage of efficient LAI,specific leaf weight, and ratio of grain to leaf area (cm2) in comparison with the MPT and the LPT varieties. The length,width, thickness, and area of top three leaves of the HPT varieties were significantly larger than those of the MPT and the LPT varieties, and these components of top three leaves were significantly and positively correlated with the number of spikelets and filled grains, grain weight per panicle, and grain yield. The flag leaf in HPT varieties was erect with sorrow leaf angle, and their leaf angle of 2nd and 3rd leaf from top increased in sequence. The plant height of the HPT varieties was higher than that of the MPT and the LPT varieties, and their leaf site of top three leaves also increased in sequence.Therefore, HPT varieties as an ideal plant type could increase the utilization efficiency of sunlight energy. The ideal plant type characteristics and their adjuncts for the HPT varieties are proposed in this article.

  13. Nutritive Equilibrium in Rice Plant Populations for High Yield

    Institute of Scientific and Technical Information of China (English)

    WANGBOLUN; LIUXINAN; 等

    1999-01-01

    The effects of nitrogen,phosphorus and potassium application level,seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization.There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations.The equilibrium index of nutrient amount ,content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2.The optimum nutritive proportion of nitrogen:phosphorus:potassium assimilated by the plants was about 10:2:9 at the ripening stage.But the content and the proportion varied with the growth stages,Therefore,the nutrient in rice plant populations should be in a dynamic equilibrium.So as to achieve high yield.

  14. 树木-水稻农林系统中害虫的侵害%Infestation of insect pests in tree-rice agroforestry system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The prevalence of insect pests was studied on rice BR11 (mukta) as understory crop grown in association with 11 years old selected tree species viz, Akashmoni, Jhau and Albida in the field laboratory of the Department of Agroforestry, Bangladesh Agricultural University (BAU), Mymensingh during the period from July to December, 2003. Among the three species Albida and Jhau possessed the largest canopy and there light penetration rate were high. On the other hand, Akashmoni had the lowest canopy but it penetrated low amount of light. Albida-rice association showed the lowest infestation of major rice insects followed by Jhau-rice association, while Akashmoni-rice association showed the highest insect infestation. Light intensity in the control plot (absent of tree species) was maximum and it caused minimum severity of insects infestation as compared to other associations. From the result it appeared that light interception has the relationship with insect population in rice. Therefore, tree species having sparse canopy which allowed easy penetration of sunlight is suitable for tree-rice agroforestry system.%本文比较研究了10种水稻害虫在3个树种(Akashmoni, Jhau 和 Albida)与稻子混栽的农-林复合生态系统中的发生情况,通过3个树种的冠幅大小、透光率以及害虫发生程度相比较,提出农-林复合生态系统中,水稻害虫的发生与树冠的透光率呈密切的负相关关系.图1参13.

  15. PLANT SPACING AND WEED MANAGEMENT TECHNIQUES INFLUENCE WEED COMPETITIVENESS OF DRUM SEEDED RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    B N Sandeep Nayak

    2014-11-01

    Full Text Available Direct wet seeded-rice sown through drum seeder, a potential wise rice production system in the present-day scenario, is subject to severe weed infestation and, therefore, development of a sustainable weed management strategy is crucial for its wide spread adoption. The present study was conducted in kharif 2012 at department of agronomy division with NLR-33358 (SOMASILA using six planting densities under five weed management conditions. The plant spacing tried were: 20cm x 7cm, 20 cm x 10.5 cm, 20 cm x 14 cm, 20 cm x 17.5 cm and 20 cm x 24.5cm and 20 cm x15cm. with a plant density of 71, 47, 35, 28, 20 and 33 hills m-2, respectively and five weed management practices viz., weedy check (W1, hand weeding at 20 and 40 DAS (W2, cono weeding at 20 and 40 with modified cono weeder (W3, pre-emergence application of anilofos @ 0.375 kg a.i ha-1 followed by post-emergence application of 2, 4 D sodium salt @ 1.0 kg a.i ha-1 20-25 DAS (W4, pre-emergence application of pendimethalin @1.0 kg a.i ha-1 followed by post-emergence application of bispyribac sodium @ 20 g a.i ha-1 30 DAS ( W5. . The experiment was laid out in strip- plot design with three replications assigning weed management techniques in vertical factor and plant spacing in horizontal factor. Direct wet seeded rice field was infested with 12 and 22 weed species, kharif -2012 season having Echinochloa colona, Leptochloa chinensis, Digitaria aescendens, Cyperus iriaand Eleusine indicaas the predominant weeds. Rice spacing exerted significant influence on both weed pressure and yield performance of crop. With the increase in plant spacing weed dry matter decreased but rice yield increased. In this season, among different plant densities, the highest density of 71 hills m-2(D1 resulted in minimum weed density, weed drymatter, and more number of tillers m-2 and maximum drymatter production at all stages of plant growth. closest spacing resulted in maximum weed suppression, but among various rice

  16. Qualitative and Quantitative Differences in Herbivore-Induced Plant Volatile Blends from Tomato Plants Infested by Either Tuta absoluta or Bemisia tabaci.

    Science.gov (United States)

    Silva, Diego B; Weldegergis, Berhane T; Van Loon, Joop J A; Bueno, Vanda H P

    2017-01-03

    Plants release a variety of volatile organic compounds that play multiple roles in the interactions with other plants and animals. Natural enemies of plant-feeding insects use these volatiles as cues to find their prey or host. Here, we report differences between the volatile blends of tomato plants infested with the whitefly Bemisia tabaci or the tomato borer Tuta absoluta. We compared the volatile emission of: (1) clean tomato plants; (2) tomato plants infested with T. absoluta larvae; and (3) tomato plants infested with B. tabaci adults, nymphs, and eggs. A total of 80 volatiles were recorded of which 10 occurred consistently only in the headspace of T. absoluta-infested plants. Many of the compounds detected in the headspace of the two herbivory treatments were emitted at different rates. Plants damaged by T. absoluta emitted at least 10 times higher levels of many compounds compared to plants damaged by B. tabaci and intact plants. The multivariate separation of T. absoluta-infested plants from those infested with B. tabaci was due largely to the chorismate-derived compounds as well as volatile metabolites of C18-fatty acids and branched chain amino acids that had higher emission rates from T. absoluta-infested plants, whereas the cyclic sesquiterpenes α- and β-copaene, valencene, and aristolochene were emitted at significantly higher levels from B. tabaci-infested plants. Our findings imply that feeding by T. absoluta and B. tabaci induced emission of volatile blends that differ quantitatively and qualitatively, providing a chemical basis for the recently documented behavioral discrimination by two generalist predatory mirid species, natural enemies of T. absoluta and B. tabaci employed in biological control.

  17. 不同虫压下转Bt基因水稻与非转基因水稻生态适合度差异%Differences in Ecological Fitness Between Bt Transgenic Rice and Regular Rice Under Different Insect-infestation Pressures

    Institute of Scientific and Technical Information of China (English)

    张富丽; 刘文娟; 雷绍荣; 郭灵安; 刘勇; 佟洪金; 尹全; 陶李; 王东; 周西全; 常丽娟; 宋君

    2012-01-01

    For understanding the possibility and efficiency of foreign gene spread in nature and some potential ecological risk of transgenic rice, a experiment was carried out to investigate the effect of foreign Bt gene insertion on the ecological fitness of the transgenic rice plant. Three Bt transgenic rice cultivars, 'Bt63', 'RF and 'R2', and a non-transgenic rice '11-838' were used as materials. The insect-resistant transgenic and the non-transgenic rice plants were inter-cropped pair-wisely. Two levels of rice stem borer-infestation were set up. The vegetative growth, seed-setting and the resistance to rice stem borers were compared between transgenic and non-transgenic lines. The results showed that both number of tillers and fresh weight of the transgenic rice plant were no differences compared with the control under low pest-infestation pressure, but the plant height, spike length and weight were all lower than those of the non-transgenic rice plant, and 'Bt63' and 'R2' were significantly different compared with the control. On the contrary, the number of tillers, spike weight and the length of the transgenic rice plant under high pest-infestation level were significantly higher than those of the control. The plant height was different amongst the transgenic lines, which was presumably because of the receptive cultivars' traits. Both the number of seeds and thousand-grain weight were no differences between the transgenic and non-transgenic rice lines under two different insect-infestation pressures, suggesting that the effect of foreign Bt gene on seed setting was not significant. In contrast to the non-transgenic rice, three Bt transgenic rice lines displayed a higher resistance to rice stem borer. The fitness of the Bt transgenic rice was distinctly higher under high pest-infestation pressure, which indicated that the effect of foreign Bt gene on the insect-resistance of plant recipients was distinct. At the same time, lower fitness cost of Bt transgenic rice in

  18. Transpiration rates of rice plants treated with Trichoderma spp.

    Science.gov (United States)

    Doni, Febri; Anizan, I.; Che Radziah C. M., Z.; Yusoff, Wan Mohtar Wan

    2014-09-01

    Trichoderma spp. are considered as successful plant growth promoting fungi and have positive role in habitat engineering. In this study, the potential for Trichoderma spp. to regulate transpiration process in rice plant was assessed experimentally under greenhouse condition using a completely randomized design. The study revealed that Trichoderma spp. have potential to enhance growth of rice plant through transpirational processes. The results of the study add to the advancement of the understanding as to the role of Trichoderma spp. in improving rice physiological process.

  19. Involvement of Jasmonate- signaling pathway in the herbivore-induced rice plant defense

    Institute of Scientific and Technical Information of China (English)

    XU Tao; ZHOU Qiang; CHEN Wei; ZHANG Guren; HE Guofeng; GU Dexiang; ZHANG Wenqing

    2003-01-01

    The expression patterns of eight defense- related genes in the herbivore-infested and jasmonate- treated (jasmonic acid, JA and its derivative MeJA) rice leaves were analyzed using RT-PCR. The results showed that Spodoptera litura Fabricius (Lepidoptera: Noctuidae) herbivory induced the expression of lipoxygenase (LOX) and allene oxide synthase (AOS) genes that are involved in the jasmonate-signaling pathway. Moreover, S. Litura damage resulted in the expression of farnesyl pyrophosphate synthase (FPS), Bowman-birk proteinase inhibitor (BBPI), phenylalanine ammonia-lyase (PAL) and other rice defense- related genes that were also induced by aqueous JA treatment or gaseous MeJA treatment. These indicated that in rice leaves, the JA-related signaling pathway was involved in the S. Litura-induced chemical defense. Mechanical damage and brown planthopper (BPH), Nilaparvata lugens (Stal) (Homoptera: Delphacidae) damage induced the expression of LOX gene, but both treatments did not induce the expression of AOS gene. However, BPH damage induced the expression of acidic pathogen-related protein 1 (PR-1a), Chitinase (PR-3), and PAL genes, which is involved in the salicylate- signaling pathway. It was suggested that salicylate-related signaling pathway or other pathways, rather than jasmonate-signaling pathway was involved in the BPH-induced rice plant defense.

  20. Infestation of Anthonomus grandis (Coleoptera: Curculionidae on re-sprout of cotton plants

    Directory of Open Access Journals (Sweden)

    José Fernando Jurca Grigolli

    2015-06-01

    Full Text Available The destruction of cotton crop residues at the end of the crop cycle is a key strategy for the phytosanitary crop management, since its off-season re-sprout can provide sites for feeding and oviposition of pests such as the boll weevil. This study aimed to evaluate the re-sprout capacity of cotton cultivars, as well as their infestation by Anthonomus grandis. A randomized blocks design, in a 3 x 2 factorial arrangement, with three cultivars (FM 910, DeltaOPAL and NuOPAL, two mowing heights (10 cm and 20 cm and four replications, was used. Weekly evaluations were carried out for measuring the percentage of plant re-sprout for both mowing heights, percentage of flower buds infested by the boll weevil and number of adults per re-sprout. Plants mowed at 10 cm presented a lower sprout capacity and consequently less flower buds, reducing the boll weevil population density in the area, while plants mowed at 20 cm showed high re-sprouts rates, seven days after mowing. The FM 910 cultivar had the highest number of re-sprout plants, while the DeltaOPAL cultivar showed the highest number of flower buds and adults per plant, as well as the highest percentage of buds damaged by the boll weevil.

  1. [Climatic suitability of single cropping rice planting region in China].

    Science.gov (United States)

    Duan, Ju-Qi; Zhou, Guang-Sheng

    2012-02-01

    To clarify the leading climate factors affecting the distribution of single cropping rice planting region in China at national and annual temporal scales and to reveal the potential distribution and climatic suitability divisions of this planting region in China could not only provide scientific basis for optimizing the allocation of single cropping rice production, modifying planting pattern, and introducing fine varieties, but also ensure the food security of China. In this paper, the potential climate factors affecting the single cropping rice distribution in China at regional and annual scales were selected from related literatures, and the single cropping rice geographic information from the national agro-meteorological observation stations of China Meteorological Administration (CMA), together with the maximum entropy model (MaxEnt) and spatial analyst function of Arc-GIS software, were adopted to clarify the leading climate factors affecting the potential distribution of single cropping rice planting region in China, and to construct a model about the relationships between the potential distribution of the planting region and the climate. The results showed that annual precipitation, moisture index, and days of not less than 18 degrees C stably were the leading climate factors affecting the potential distribution of single cropping rice planting region in China, with their cumulative contribution rate reached 94.5% of all candidate climate factors. The model constructed in this paper could well simulate the potential distribution of single cropping rice planting region in China. According to the appearance frequency, the low, medium and high climatic suitability divisions of single cropping rice planting region in China were clarified, and the climate characteristics of the planting region in each climatic suitability division were analyzed.

  2. Microbial community structure in the rhizosphere of rice plants

    Directory of Open Access Journals (Sweden)

    Björn eBreidenbach

    2016-01-01

    Full Text Available The microbial community in the rhizosphere environment is critical for the health of land plants and the processing of soil organic matter. The objective of this study was to determine the extent to which rice plants shape the microbial community in rice field soil over the course of a growing season. Rice (Oryza sativa was cultivated under greenhouse conditions in rice field soil from Vercelli, Italy and the microbial community in the rhizosphere of planted soil microcosms was characterized at four plant growth stages using quantitative PCR and 16S rRNA gene pyrotag analysis and compared to that of unplanted bulk soil. The abundances of 16S rRNA genes in the rice rhizosphere were on average twice that of unplanted bulk soil, indicating a stimulation of microbial growth in the rhizosphere. Soil environment type (i.e. rhizosphere versus bulk soil had a greater effect on the community structure than did time (e.g. plant growth stage. Numerous phyla were affected by the presence of rice plants, but the strongest effects were observed for Gemmatimonadetes, Proteobacteria and Verrucomicrobia. With respect to functional groups of microorganisms, potential iron reducers (e.g. Geobacter, Anaeromyxobacter and fermenters (e.g. Clostridiaceae, Opitutaceae were notably enriched in the rhizosphere environment. A Herbaspirillum species was always more abundant in the rhizosphere than bulk soil and was enriched in the rhizosphere during the early stage of plant growth.

  3. The effect of dehydration on plant regeneration and some physiology characters in rice calli

    Institute of Scientific and Technical Information of China (English)

    ZHAOChengzhang; WULianbin; YANGChangdeng; QIXiufang

    1997-01-01

    The plant regeneration frequencies of calli from plant tissue and cell culture, especially that of the calli from rice tissue culture and rice anther culture, and that of the foreign-DNA-transfor-matlon-derived rice calli is very low (usually 10-15%). It is therefor very important to improve the plant regeneration frequency of rice calli.

  4. Transformation of japonica rice with RHL gene and salt tolerance of the transgenic rice plant

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Overexpression of the yeast HAL2 gene increases salt tolerance of yeast and plant. Rice HAL2-like (RHL) gene was introduced into a japonica rice cultivar HJ19 with Agrobacterium tumefaciens-mediated transformation. Transgenic plants in R0 generation were selected on the principle of GUS-positive, RHL gene PCR-positive and normal growth. Hygromycin-resistant plants of some transgenic lines in R1 generation increased salt tolerance during the seedling and booting stage, being less damaged in the cytomembrane and stronger in leaf tissue viability under salt stress during booting period. Southern analysis of transgenic lines tolerant to salt in R1 generation showed that the RHL gene expression cassette had been successfully integrated into rice genome. Moreover, gene engineering breeding methodology and really salt-tolerant rice cultivar were discussed.

  5. Do rice water weevils and rice stem borers compete when sharing a host plant?

    Institute of Scientific and Technical Information of China (English)

    Sheng-wei SHI; Yan HE; Xiang-hua JI; Ming-xing JIANG; Jia-an CHENG

    2008-01-01

    The rice water weevil (RWW) Lissorhoptrus oryzophilus Knsehel (Coleoptera: Curculionidae) is an invasive insect pest office Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepi-doptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 24 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated nega-tively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.

  6. Dark septate endophyte decreases stress on rice plants.

    Science.gov (United States)

    Santos, Silvana Gomes Dos; Silva, Paula Renata Alves da; Garcia, Andres Calderin; Zilli, Jerri Édson; Berbara, Ricardo Luis Louro

    2016-12-27

    Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.

  7. Effects of herbivore-induced rice volatiles on the host selection behavior of brown planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    It has been suggested that herbivore would react to volatiles produced by herbivore infested plant due to potential change, either positive or negative, in the acceptability of the host plant. This hypothesis was tested for the brown planthopper (BPH) in the laboratory. Sixteen components of the headspace volatiles from rice seedlings with different treatments were collected with SPME and Tenax-TA trap and analyzed with GC and GC-MS. Significant differences in volatile emissions were observed for rice plants with different treatments. Undamaged control plants, mechanically damaged plants and the plants infested by BPH for 1 or 2 d emitted much lower amounts of volatiles compared to the plants infested by BPH for 3 or 5 d. The plants infested by BPH for 3 or 5 d emitted several volatiles that were not detected in undamaged control plants, mechanically damaged plants or the plants infested by BPH for 1 or 2 d. Spodoptera litura infested plants released much higher amounts of volatiles than those in all other treatments, and the contents of several green leaf volatiles, methyl salicylate and terpenoids increased dramatically. In dual-choice flight tunnel experiments, adult BPH females showed no significant preference between the untreated healthy plants and mechanically damaged plants or the plants infested by BPH adult females. However, rice plants damaged by S. litura had a clearly repellent effects on BPH adult females compared to healthy undamaged plants, mechanically damaged plants or the plants infested by BPH.

  8. Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores

    Science.gov (United States)

    Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

    2015-01-01

    Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motifs and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity. DOI: http://dx.doi.org/10.7554/eLife.04805.001 PMID:26083713

  9. Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores.

    Science.gov (United States)

    Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

    2015-06-17

    Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motives and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity.

  10. Biological control of broad-leaved dock infestation in wheat using plant antagonistic bacteria under field conditions.

    Science.gov (United States)

    Abbas, Tasawar; Zahir, Zahir Ahmad; Naveed, Muhammad; Aslam, Zubair

    2017-06-01

    Conventional weed management systems have produced many harmful effects on weed ecology, human health and environment. Biological control of invasive weeds may be helpful to minimize these harmful effects and economic losses incurred to crops by weeds. In our earlier studies, plant antagonistic bacteria were obtained after screening a large number of rhizobacteria for production of phytotoxic substances and effects on wheat and its associated weeds under laboratory conditions. In this study, five efficient strains inhibitory to broad-leaved dock and non-inhibitory to wheat were selected and applied to broad-leaved dock co-seeded with wheat both in pot trial and chronically infested field trial. Effects of plant antagonistic bacteria on the weed and infested wheat were studied at tillering, booting and harvesting stage of wheat. The applied strains significantly inhibited the germination and growth of the weed to variable extent. Similarly, variable recovery in losses of grain and straw yield of infested wheat from 11.6 to 68 and 13 to 72.6% was obtained in pot trial while from 17.3 to 62.9 and 22.4 to 71.3% was obtained in field trial, respectively. Effects of plant antagonistic bacteria were also evident from the improvement in physiology and nutrient contents of infested wheat. This study suggests the use of these plant antagonistic bacteria to biologically control infestation of broad-leaved dock in wheat under field conditions.

  11. Transgenic strategies to confer resistance against viruses in rice plants

    Directory of Open Access Journals (Sweden)

    Takahide eSasaya

    2014-01-01

    Full Text Available Rice (Oryza sativa L. is cultivated in more than 100 countries and supports nearly half of the world’s population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. In an effort to improve control, many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA-interference (RNAi, also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral Achilles’ heel gene to target for RNAi attack when engineering plants.

  12. Plant growth stage-specific injury and economic injury level for verde plant bug, Creontiades signatus (Hemiptera: Miridae), on cotton: effect of bloom period of infestation.

    Science.gov (United States)

    Brewer, Michael J; Anderson, Darwin J; Armstrong, J Scott

    2013-10-01

    Verde plant bugs, Creontiades signatus Distant (Hemiptera: Miridae), were released onto caged cotton, Cossypium hirsutum L., for a 1-wk period to characterize the effects of insect density and bloom period of infestation on cotton injury and yield in 2011 and 2012, Corpus Christi, TX. When plants were infested during early bloom (10-11 nodes above first white flower), a linear decline in fruit retention and boll load and a linear increase in boll injury were detected as verde plant bug infestation levels increased from an average of 0.5 to 4 bugs per plant. Lint and seed yield per plant showed a corresponding decline. Fruit retention, boll load, and yield were not affected on plants infested 1 wk later at peak bloom (8-9 nodes above first white flower), even though boll injury increased as infestation levels increased. Second-year testing verified boll injury but not yield loss, when infestations occurred at peak bloom. Incidence of cotton boll rot, known to be associated with verde plant bug feeding, was low to modest (plant bug were important contributors to yield decline, damage potential was greatest during the early bloom period of infestation, and a simple linear response best described the yield response-insect density relationship at early bloom. Confirmation that cotton after peak bloom was less prone to verde plant bug injury and an early bloom-specific economic injury level were key findings that can improve integrated pest management decision-making for dryland cotton, at least under low-rainfall growing conditions.

  13. Effect of red rice interference in fourth densities of commercial rice.

    Directory of Open Access Journals (Sweden)

    Jorge García de la Osa

    2011-12-01

    Full Text Available Field trials were carried out in The Regional Research Grain Station “Sur del Jíbaro”, Sancti Spíritus, in order to study the infestation effect of 0, 12, 25, 50, 100 and 200 red rice plants per square meter (m2 on growth and yields of commercial variety J-104, seeded at 50, 100, 200 and 300 plants/m². Yield of J-104 rice variety decreased with the increase in red rice density. Crop yield decrease in the dry season ranged from 10.7 to 94.8% with infestations of 12 and 200 red rice plants /m², respectively; while in the wet season changed from 11.4 to 91.5 % with similar level in infestations. In both seasons 12 red rice plants were enough to cause a significant reduction in commercial rice yields in relation to the control treatment (without red rice infestation. The lost in crop yield was due to the decreased in panicles/ m² and filled grains per panicle, caused by the interference with red rice.

  14. European corn borer (Lepidoptera: Crambidae) infestation level and plant growth stage on whole-plant corn yield grown for silage in Virginia.

    Science.gov (United States)

    Tiwari, S; Youngman, R R; Laub, C A; Brewster, C C; Jordan, T A; Teutsch, C

    2009-12-01

    Field experiments were conducted in 2004 and 2005 to determine the effect of different levels of hand-infested third instar European corn borer, Ostrinia nubilalis (Hiibner) (Lepidoptera: Crambidae), on whole-plant yield and plant growth stage in corn, Zea mays L., grown for silage. In 2004 and 2005, European corn borer infestation level had a significant negative impact on whole-plant yield (grams of dry matter per plant) with increasing infestation; however, whole-plant yield was not significantly affected by plant growth stage in either year. In 2004, the six larvae per plant treatment caused the greatest percentage of reduction (23.4%) in mean (+/-SEM) whole-plant yield (258.5 +/- 21.0 g dry matter per plant) compared with the Bacillus thuringiensis (Bt) CrylAb control (337.3 +/- 11.1 g dry matter per plant). In 2005, the five larvae per plant treatment caused the greatest percentage of reduction (8.3%) in mean whole-plant yield (282.3 +/- 10.8 g dry matter per plant) compared with the Bt CrylAb control (307.8 +/- 8.3 g dry matter per plant). The relationship between mean whole-plant yield and European corn borer larvae infestation level from the pooled data of both years was described well by using an exponential decay model (r2 = 0.84, P = 0.0038). The economic injury level for silage corn was estimated to be approximately 73% higher than for corn grown for grain based on similar control costs and crop values. In addition, plant growth stage and European corn borer infestation level had no effect on percentage of acid detergent fiber, neutral detergent fiber, and crude protein values in either year of the study.

  15. Application of Rice Straw Compost with Different Bioactivators on the Growth and Yield of Rice Plant

    Directory of Open Access Journals (Sweden)

    Yunita Barus

    2012-01-01

    Full Text Available Turnover of organic matters to the soil can increase the efficiency of chemical fertilizers, improve the plant growthand sustain the environment. Field experiment was carried out in the Buyut Udik Village, Gunung Sugih District,Central Lampung from May to August 2009. Rice straw was composted by three kinds of decomposer (bioactivatorA, B, and C. Rice straw compost (2 Mg ha-1 was applied to the paddy-field soil that was planted by rice (Oryzasativa of Ciherang Variety. The experiment was arranged in a randomized block design with three replicates. Theresults showed that application of rice straw compost reduced the numbers of empty grain per tiller compared tocontrol (without compost in which control had the highest percentage of empty grain (15.9%. The application ofrice straw compost that was decomposed by bioactivator A gave the highest numbers of grain per panicle and yieldper plot as followed 162.5 seed and 33 kg plot-1, respectively. Application of various rice straw composts that weredecomposed by three kinds of bioactivator increased the rice grain up to 13-26% compared to control.

  16. Relationship between nutritional composition of plant species and infestation levels of thrips.

    Science.gov (United States)

    Brown, Alison S Scott; Simmonds, Monique S J; Blaney, Walter M

    2002-12-01

    Levels of soluble protein and carbohydrate (raffinose, sucrose, glucose, and fructose) in leaves from a selection of plant species were measured to determine if a relationship existed between these nutrients and infestation by Frankliniella occidentalis and Heliothrips haemorrhoidalis. Most species of host plant examined contained a higher proportion of protein than carbohydrates, and overall, leaves from species of plants that supported populations of thrips had greater levels of protein than leaves from nonhost species. New leaves and flowers that supported F. occidentalis contained high levels of carbohydrate and protein. The quantity of protein in leaves at the top of the tree, Peumus boldus, was greater than in leaves from lower levels, and the amount of feeding damage accrued by H. haemorrhoidalis was greater on the upper foliage than lower foliage. Oviposition by H. haenmorrhoidalis was positively correlated to levels of protein in host plants but not to levels of carbohydrates. Overall, levels of soluble protein in plants influenced their susceptibility to thrips more than levels of carbohydrates.

  17. Expression of snowdrop lectin (GNA) in transgenic rice plants confers resistance to rice brown planthopper.

    Science.gov (United States)

    Rao, K V; Rathore, K S; Hodges, T K; Fu, X; Stoger, E; Sudhakar, D; Williams, S; Christou, P; Bharathi, M; Bown, D P; Powell, K S; Spence, J; Gatehouse, A M; Gatehouse, J A

    1998-08-01

    Snowdrop lectin (Galanthus nivalis agglutinin; GNA) has been shown previously to be toxic towards rice brown planthopper (Nilaparvata lugens; BPH) when administered in artificial diet. BPH feeds by phloem abstraction, and causes 'hopper burn', as well as being an important virus vector. To evaluate the potential of the gna gene to confer resistance towards BPH, transgenic rice (Oryza sativa L.) plants were produced, containing the gna gene in constructs where its expression was driven by a phloem-specific promoter (from the rice sucrose synthase RSs1 gene) and by a constitutive promoter (from the maize ubiquitin ubi1 gene). PCR and Southern analyses on DNA from these plants confirmed their transgenic status, and that the transgenes were transmitted to progeny after self-fertilization. Western blot analyses revealed expression of GNA at levels of up to 2.0% of total protein in some of the transgenic plants. GNA expression driven by the RSs1 promoter was tissue-specific, as shown by immunohistochemical localization of the protein in the non-lignified vascular tissue of transgenic plants. Insect bioassays and feeding studies showed that GNA expressed in the transgenic rice plants decreased survival and overall fecundity (production of offspring) of the insects, retarded insect development, and had a deterrent effect on BPH feeding. gna is the first transgene to exhibit insecticidal activity towards sap-sucking insects in an important cereal crop plant.

  18. Production and identification of salt_tolerant transgenic rice plants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@To relieve the damage of salt to the cell, many plants accumulated some low_molecular weight organic compounds, which were called osmoprotectant, such as betaine, mannitol, and sorbitol. Therefore if the gene_encoding enzyme responsible for synthesizing the osmoprotectant was transformed into rice plants, the salt_tolerance capacity of the transgenic plants would be increased, and the enormous loss caused by salinization of soil would be reduced.

  19. Father of Hybrid Rice Plants Corn

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    New joint venture strengthens China’s position against international seed companies Yuan Longping Hi-Tech Agriculture Co.Ltd.(Longping Hi-Tech),named after the father of hybrid rice in China,announced on February 10 the establishment of a joint venture(JV) with a subsidiary of Vilmorin & Cie.

  20. The effects of Aphis fabae infestation on the antioxidant response and heavy metal content in field grown Philadelphus coronarius plants

    Energy Technology Data Exchange (ETDEWEB)

    Kafel, Alina, E-mail: akafel@us.edu.pl [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland); Nadgorska-Socha, Aleksandra [University of Silesia, Department of Ecology, Bankowa 9, PL 40-007, Katowice (Poland); Gospodarek, Janina [Agricultural University of Krakow, Department of Agricultural Environment Protection, Mickiewicza 21, PL 31-120, Krakow (Poland); Babczynska, Agnieszka; Skowronek, Magda [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland); Kandziora, Marta [University of Silesia, Department of Ecology, Bankowa 9, PL 40-007, Katowice (Poland); Rozpedek, Katarzyna [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland)

    2010-02-01

    The purpose of this study was to explore a possible relationship between the soil availability of metals and their concentrations in various parts of Philadelphuscoronarius plants. Moreover, the possible impact of an aphid infestation on the contamination and antioxidant response of plants from the urban environment of Krakow and the reference rural area of Zagaje Stradowskie (southern Poland) was analyzed. The contents of the glutathione, proline, non-protein - SH groups, antioxidants, and phosphorous and the levels of guaiacol peroxidase and catalase activity in leaves and shoots either infested or not by the aphid Aphis fabae Scop., were measured. The potential bioavailability of metals (Cd; Cu; Ni; Pb; Zn) in the soil and their concentrations in P. coronarius plants originating from both sites were compared. The antioxidant responses were generally elevated in the plants in the polluted area. Such reactions were additionally changed by aphid infestation. Generally, the concentrations of metals in the HNO{sub 3} and CaCl{sub 2} extractants of the soils from two layers at the 0-20 and 20-40 cm depths from the polluted area were higher than in those from the reference area. Such differences were found for nickel and lead (in all examined extractants), zinc (in soil extractants from the layer at 20-40 cm) and cadmium (in HNO{sub 3} extractants). Significant positive relationships between the lead concentrations in the soil and in the plants were found. In the parts of plants from the polluted area, higher concentrations of Pb and Zn (leaves and shoots) and Cd (shoots) were recorded. The shoots and leaves of plants infested with aphids had higher concentrations of Zn but lower Pb. Moreover, their leaves had higher contaminations of Cu and Ni. In conclusion, aphids affected not only the antioxidant response of the plants but also their contamination with metals, especially contamination of the leaves.

  1. Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

    Institute of Scientific and Technical Information of China (English)

    Md Mamunur RASHID; Mahbuba JAHAN; Khandakar Shariful ISLAM

    2016-01-01

    The brown planthopper (BPH),Nilaparvata lugens (Stål), appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients, nitrogen (N), phosphorus (P) and potassium (K), on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages, and changes in relative water content (RWC) of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants, and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants, which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N, K, Si, free sugar and soluble protein contents, which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N, Si, free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding, thereby contributed to higher tolerance of rice plants to brown planthopper.

  2. Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

    Directory of Open Access Journals (Sweden)

    Md Mamunur Rashid

    2016-05-01

    Full Text Available The brown planthopper (BPH, Nilaparvata lugens (Stål, appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients, nitrogen (N, phosphorus (P and potassium (K, on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages, and changes in relative water content (RWC of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants, and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants, which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N, K, Si, free sugar and soluble protein contents, which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N, Si, free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding, thereby contributed to higher tolerance of rice plants to brown planthopper.

  3. OsNPR1 negatively regulates herbivore-induced JA and ethylene signaling and plant resistance to a chewing herbivore in rice.

    Science.gov (United States)

    Li, Ran; Afsheen, Sumera; Xin, Zhaojun; Han, Xiu; Lou, Yonggen

    2013-03-01

    NPR1 (a non-expressor of pathogenesis-related genes1) has been reported to play an important role in plant defense by regulating signaling pathways. However, little to nothing is known about its function in herbivore-induced defense in monocot plants. Here, using suppressive substrate hybridization, we identified a NPR1 gene from rice, OsNPR1, and found that its expression levels were upregulated in response to infestation by the rice striped stem borer (SSB) Chilo suppressalis and rice leaf folder (LF) Cnaphalocrocis medinalis, and to mechanical wounding and treatment with jasmonic acid (JA) and salicylic acid (SA). Moreover, mechanical wounding induced the expression of OsNPR1 quickly, whereas herbivore infestation induced the gene more slowly. The antisense expression of OsNPR1 (as-npr1), which reduced the expression of the gene by 50%, increased elicited levels of JA and ethylene (ET) as well as of expression of a lipoxygenase gene OsHI-LOX and an ACC synthase gene OsACS2. The enhanced JA and ET signaling in as-npr1 plants increased the levels of herbivore-induced trypsin proteinase inhibitors (TrypPIs) and volatiles, and reduced the performance of SSB. Our results suggest that OsNPR1 is an early responding gene in herbivore-induced defense and that plants can use it to activate a specific and appropriate defense response against invaders by modulating signaling pathways.

  4. Biochar amendment reduced methylmercury accumulation in rice plants

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Rui; Wang, Yongjie [School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People’s Republic of China (China); Zhong, Huan, E-mail: zhonghuan@nju.edu.cn [School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People’s Republic of China (China); Environmental and Life Sciences Program (EnLS), Trent University, Peterborough, Ontario (Canada)

    2016-08-05

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

  5. Influence of growing location and cultivar on Rhyzopertha dominica (Coleoptera: Bostrichidae) and Sitophilus oryzae (Coleoptera: Curculionidae) infestation of rough rice

    Institute of Scientific and Technical Information of China (English)

    FRANK H. ARTHUR; RUSTY C. BAUTISTA; TERRENCE J. SIEBENMORGEN

    2007-01-01

    Long-grain rice cultivars Cocodrie, Wells, and XP 723 grown in three locations (Hazen, MO; Essex and Newport, AR, USA), and medium-grain rice cultivars Bengal and XP 713 grown in two locations (Jonesboro and Lodge Corner, AR, USA), were harvested and assayed for susceptibility to Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), the lesser grain borer, and Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the rice weevil, on rice held at 27℃ 57% and 75% relative humidity (RH).Separate samples from the same harvest lots were also analyzed for the physical characteristics of brown rice yield, percentage whole kernels and kernel thickness. Progeny production and feeding damage of R. dominica were significantly different among long-grain cultivars within two of the three locations (P < 0.05), but not for location or RH (P ≥ 0.05), while progeny production of S. oryzae was different among cultivars, location, and RH (P < 0.05). On medium-grain rice, both cultivar and location were significant for progeny production of R. dominica, but not RH, while cultivar and RH were significant for progeny production of S. oryzae, but not location. On both rice types, feeding damage of R. dominica followed the same trends and was always strongly positively correlated with progeny production (P < 0.05), but for S. oryzae there were several instances in which progeny production was not correlated with feeding damage (P ≥ 0.05). Physical characteristics of both rice types were statistically significant (P < 0.01) but actual numerical differences were extremely small, and were generally not correlated with progeny production of either species. Results indicate that the location in which a particular rice cultivar is grown, along with its characteristics, could affect susceptibility of the rice to R. dominica and S. oryzae.

  6. Interaction of Phytophagous Insects with Salmonella enterica on Plants and Enhanced Persistence of the Pathogen with Macrosteles quadrilineatus Infestation or Frankliniella occidentalis Feeding: e79404

    National Research Council Canada - National Science Library

    José Pablo Soto-Arias; Russell Groves; Jeri D Barak

    2013-01-01

    ... S. enterica populations were found on leaves infested with Macrosteles quadrilineatus. In contrast, pathogen populations among plants exposed to Frankliniella occidentalis or Myzus persicae were similar to those without insects...

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

    Science.gov (United States)

    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.

  8. Socio-economic impacts and determinants of parasitic weed infestation in rainfed rice systems of sub-Saharan Africa

    NARCIS (Netherlands)

    N'cho, A.S.

    2014-01-01

    Keywords: rice; weed; weed management practices, adoption, impact, parasitic weeds; Rhamphicarpa fistulosa; Striga asiatica; Striga hermonthica, double hurdle model; multivariate probit, productivity, stochastic frontier analysis, data envelopment analy

  9. Enantioselective degradation of metalaxyl in grape, tomato, and rice plants.

    Science.gov (United States)

    Wang, Meiyun; Hua, Xiude; Zhang, Qing; Yang, Yu; Shi, Haiyan; Wang, Minghua

    2015-02-01

    Enantioselective biodegradation of chiral pesticide metalaxyl in grape, tomato, and rice plants under field conditions were studied. Metalaxyl enantiomers were completely separated with a resolution (Rs) of 5.01 by high-performance liquid chromatography (HPLC) based on a cellulose tris (3-chloro-4-methyl phenyl carbamate) chiral column (Lux Cellulose-2). Metalaxyl enantiomers from matrixes were extracted by acetonitrile and purged using Cleanert Alumina-A solid phase extraction (SPE). The linearity, recovery, precision, sensitivity, and matrix effect of the method were assessed. The result showed that significant stereoselectivity occurred in grape, tomato, and rice plants. In grape, (+)-S-metalaxyl with a half-life of 5.5 d degraded faster than (-)-R-metalaxyl with that of 6.9 d, and the enantiomer fraction (EF) value reached 0.37 at 21 d. The same enantioselectivity was observed in tomato, and the half-life was 2.2 d for the S-enantiomer and 3.0 d for the R-enantiomer. The EF values decreased from 0.49 of 0 d to 0.26 of 14 d. On the other hand, a preferential degradation of the R-form was found in rice plants, with an EF value of 0.70 at 14 d, and the corresponding half-life was 2.3 d for the R-form and 2.8 d for the S-form. © 2014 Wiley Periodicals, Inc.

  10. Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.

    Directory of Open Access Journals (Sweden)

    Bhabesh Dutta

    Full Text Available The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6 colony forming units (CFUs/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion. Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating, respectively and they were not significantly different (P = 0.67. The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03. None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be

  11. Interactions of Seedborne Bacterial Pathogens with Host and Non-Host Plants in Relation to Seed Infestation and Seedling Transmission

    Science.gov (United States)

    Dutta, Bhabesh; Gitaitis, Ronald; Smith, Samuel; Langston, David

    2014-01-01

    The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea) to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean) and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1×106 colony forming units (CFUs)/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion). Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO) assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating), respectively and they were not significantly different (P = 0.67). The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating) and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03). None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be colonized

  12. Infection Courts in Watermelon Plants Leading to Seed Infestation by Fusarium oxysporum f. sp. niveum.

    Science.gov (United States)

    Petkar, Aparna; Ji, Pingsheng

    2017-07-01

    Fusarium wilt incited by Fusarium oxysporum f. sp. niveum is a seed-transmitted disease that causes significant yield loss in watermelon production. The pathogen may infect watermelon seeds latently, which can be an important inoculum source and contribute to severe disease outbreak. However, information regarding infection courts of F. oxysporum f. sp. niveum leading to infestation of watermelon seeds is limited. To determine how seeds in watermelon fruit can be infested by F. oxysporum f. sp. niveum during the watermelon growing season, greenhouse and field experiments were conducted in 2014 and 2015 where watermelon flowers and immature fruit were inoculated with F. oxysporum f. sp. niveum. Seeds were extracted from mature watermelon fruit, and infestation of watermelon seeds was determined by isolation of F. oxysporum f. sp. niveum and further confirmed by real-time polymerase chain reaction (PCR) analysis. Inoculation of the pericarp of immature fruit resulted in 17.8 to 54.4% of infested seeds under field conditions and 0.6 to 12.8% of infested seeds under greenhouse conditions when seeds were not surface disinfested prior to isolation. Seed infestation was also detected in 0 to 4.5% of the seeds when seeds were surface disinfested prior to isolation. Inoculation of pistil resulted in 0 to 7.2% and 0 to 18.3% of infested seeds under greenhouse and field conditions when seeds were surface disinfested or not disinfested before isolation, respectively. Inoculation of peduncle resulted in 0.6 to 6.1% and 0 to 10.0% of infested seeds in the greenhouse and field experiments when seeds were surface disinfested or not disinfested before isolation, respectively. Seed infestation was also detected in all the experiments using real-time PCR assay when pericarp or pistil was inoculated, and in three of four experiments when peduncle was inoculated, regardless of whether seeds were surface disinfested or not disinfested. Pericarp and peduncle of immature watermelon fruit

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Agrobacterium-transformed rice plants expressing synthetic cryIA(b) and cryIA(c) genes are highly toxic to striped stem borer and yellow stem borer.

    Science.gov (United States)

    Cheng, X; Sardana, R; Kaplan, H; Altosaar, I

    1998-03-17

    Over 2,600 transgenic rice plants in nine strains were regenerated from >500 independently selected hygromycin-resistant calli after Agrobacterium-mediated transformation. The plants were transformed with fully modified (plant codon optimized) versions of two synthetic cryIA(b) and cryIA(c) coding sequences from Bacillus thuringiensis as well as the hph and gus genes, coding for hygromycin phosphotransferase and beta-glucuronidase, respectively. These sequences were placed under control of the maize ubiquitin promoter, the CaMV35S promoter, and the Brassica Bp10 gene promoter to achieve high and tissue-specific expression of the lepidopteran-specific delta-endotoxins. The integration, expression, and inheritance of these genes were demonstrated in R0 and R1 generations by Southern, Northern, and Western analyses and by other techniques. Accumulation of high levels (up to 3% of soluble proteins) of CryIA(b) and CryIA(c) proteins was detected in R0 plants. Bioassays with R1 transgenic plants indicated that the transgenic plants were highly toxic to two major rice insect pests, striped stem borer (Chilo suppressalis) and yellow stem borer (Scirpophaga incertulas), with mortalities of 97-100% within 5 days after infestation, thus offering a potential for effective insect resistance in transgenic rice plants.

  17. Role of ethylene signaling in the production of rice volatiles induced by the rice brown planthopper Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    LU Yujie; WANG Xia; LOU Yonggen; CHENG Jiaan

    2006-01-01

    Ethylene signaling pathway plays an important role in induced plant direct defense against herbivores and pathogens; however, up to now, only few researches have focused on its role in induced plant indirect defense, i.e. the release of herbivore-induced volatiles, and the results are variable.Using a model system consisting of rice plants, the rice brown planthopper Nilaparvata lugens and its egg parasitoid Anagrus nilaparvatae, we examined the role of ethylene signaling in the production of rice volatiles induced by N. lugens by measuring both the timing of herbivore-induced ethylene levels and the relationships between ethylene, rice volatiles and attraction of the parasitoid. N. lugens infestation significantly enhanced the release of ethylene during 2-24 h after infestation. Plants treated with ethephon, a compound that breaks down to release ethylene at cytoplasmic pH, released volatiles profiles similar to those released by N.lugens-infested plants,and both of them showed an equal attraction of the parasitoid. Moreover, pretreatment with 1-MCP, an inhibitor of ethylene perception, reduced the release of most of rice volatiles whose amount was enhanced by N.lugens infestation and decreased the attractiveness to the parasitoid. These results demonstrate that ethylene signaling is required for the production of rice volatiles induced by N.lugens.

  18. Volatiles from whitefly-infested plants elicit a host-locating response in the parasitoid, Encarsia formosa.

    Science.gov (United States)

    Birkett, M A; Chamberlain, K; Guerrieri, E; Pickett, J A; Wadhams, L J; Yasuda, T

    2003-07-01

    The blend of volatile compounds emitted by bean plants (Phaseolus vulgaris) infested with greenhouse whitefly (Trialeurodes vaporariorum) has been studied comparatively with undamaged plants and whiteflies themselves. Collection of the volatiles and analysis by gas chromatography revealed more than 20 compounds produced by plants infested with whitefly. Of these, 4 compounds, (Z)-3-hexen-1-ol, 4,8-dimethyl-1,3,7-nonatriene, 3-octanone, and one unidentified compound were emitted at higher levels than from the undamaged control plants. Synthetic (Z)-3-hexen-1-ol, 4,8-dimethyl-1,3,7-nonatriene, or 3-octanone all elicited a significant increase in oriented flight and landing on the source by the parasitoid, Encarsia formosa, in wind tunnel bioassays. Two-component mixtures of the compounds and the three-component mixture all elicited a similar or, in most cases, a better response by the parasitoid, the most effective being a mixture of (Z)-3-hexen-1-ol and 3-octanone. These results demonstrate that E. formosa uses volatiles from the plant-host complex as olfactory cues for host location.

  19. Effect of Nitrogen on Water Content, Sap Flow, and Tolerance of Rice Plants to Brown Planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; S. VILLAREAL; YU Xiao-ping; K. L. HEONG; HU Cui

    2004-01-01

    Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages,and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthopper (BPH), Nilaparvata lugens were determined in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research Institute (IRRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the increase of nitrogen content in rice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility to BPH damage on rice plants applied with nitrogen fertilizer.

  20. Spread of herbicide-resistant weedy rice (red rice, Oryza sativa L.) after 5 years of Clearfield rice cultivation in Italy.

    Science.gov (United States)

    Busconi, M; Rossi, D; Lorenzoni, C; Baldi, G; Fogher, C

    2012-09-01

    The weedy relative of cultivated rice, red rice, can invade and severely infest rice fields, as reported by rice farmers throughout the world. Because of its close genetic relationship to commercial rice, red rice has proven difficult to control. Clearfield (Cl) varieties, which are resistant to the inhibiting herbicides in the chemical group AHAS (acetohydroxyacid synthase), provide a highly efficient opportunity to control red rice infestations. In order to reduce the risk of herbicide resistance spreading from cultivated rice to red rice, stewardship guidelines are regularly released. In Italy, the cultivation of Cl cultivars started in 2006. In 2010, surveillance of the possible escape of herbicide resistance was carried out; 168 red rice plants were sampled in 16 fields from six locations containing Cl and traditional cultivars. A first subsample of 119 plants was analysed after herbicide treatment and the resistance was found in 62 plants. Of these 119 plants, 78 plants were randomly selected and analysed at the level of the AHAS gene to search for the Cl mutation determining the resistant genotype: the Cl mutation was present in all the resistant plants. Nuclear and chloroplast microsatellite markers revealed a high correlation between genetic similarity and herbicide resistance. The results clearly show that Cl herbicide-resistant red rice plants are present in the field, having genetic relationships with the Cl variety. Finding plants homozygous for the mutation suggests that the crossing event occurred relatively recently and that these plants are in the F2 or later generations. These observations raise the possibility that Cl red rice is already within the cultivated rice seed supply.

  1. Enhanced disease resistance and drought tolerance in transgenic rice plants overexpressing protein elicitors from Magnaporthe oryzae.

    Science.gov (United States)

    Wang, Zhenzhen; Han, Qiang; Zi, Qian; Lv, Shun; Qiu, Dewen; Zeng, Hongmei

    2017-01-01

    Exogenous application of the protein elicitors MoHrip1 and MoHrip2, which were isolated from the pathogenic fungus Magnaporthe oryzae (M. oryzae), was previously shown to induce a hypersensitive response in tobacco and to enhance resistance to rice blast. In this work, we successfully transformed rice with the mohrip1 and mohrip2 genes separately. The MoHrip1 and MoHrip2 transgenic rice plants displayed higher resistance to rice blast and stronger tolerance to drought stress than wild-type (WT) rice and the vector-control pCXUN rice. The expression of salicylic acid (SA)- and abscisic acid (ABA)-related genes was also increased, suggesting that these two elicitors may trigger SA signaling to protect the rice from damage during pathogen infection and regulate the ABA content to increase drought tolerance in transgenic rice. Trypan blue staining indicated that expressing MoHrip1 and MoHrip2 in rice plants inhibited hyphal growth of the rice blast fungus. Relative water content (RWC), water usage efficiency (WUE) and water loss rate (WLR) were measured to confirm the high capacity for water retention in transgenic rice. The MoHrip1 and MoHrip2 transgenic rice also exhibited enhanced agronomic traits such as increased plant height and tiller number.

  2. Multivariate Analysis of Metal Levels in Paddy Soil, Rice Plants, and Rice Grains: A Case Study from Shakargarh, Pakistan

    Directory of Open Access Journals (Sweden)

    Saadia R. Tariq

    2013-01-01

    Full Text Available The present study aims at determining the relationship between trace metal levels in paddy soils, rice plants, and rice grains obtained from these plants. The levels of selected metals (Fe, Co, Ni, Cd, Pb, and Cr were determined by atomic absorption spectrophotometry in the soil, rice plants, and rice grain samples collected from paddy fields. All the metals were present at enhanced levels in paddy soil. Among the selected metals, Fe, Ni, Cd, and Cr were predominantly associated with oxidizable fraction. The metals such as Cr, Ni, Co, and Fe were significantly positively correlated in soil and plants, but no such correlation was observed in soil-grain matrix evidencing that these metals have a soil-based origin in the plants, but they were not translocated to grains. The Pb content of soil was strongly positively correlated with plants as well as the grains. The principal component analysis and cluster analysis were used to depict the origin of enhanced metal levels in rice plants. Under the given field conditions, different metals possess different translocation behaviours from soil to roots to shoots to grains. There is a dire need to implement the strategies for wise and optimum use of agrochemicals.

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

    Science.gov (United States)

    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.

  4. Silicon alleviates drought stress of rice plants by improving plant water status, photosynthesis and mineral nutrient absorption.

    Science.gov (United States)

    Chen, Wei; Yao, Xiaoqin; Cai, Kunzheng; Chen, Jining

    2011-07-01

    Drought is a major constraint for rice production in the rainfed lowlands in China. Silicon (Si) has been verified to play an important role in enhancing plant resistance to environmental stress. Two near-isogenic lines of rice (Oryza sativa L.), w-14 (drought susceptible) and w-20 (drought resistant), were selected to study the effects of exogenous Si application on the physiological traits and nutritional status of rice under drought stress. In wet conditions, Si supply had no effects on growth and physiological parameters of rice plants. Drought stress was found to reduce dry weight, root traits, water potential, photosynthetic parameters, basal quantum yield (F(v)/F(0)), and maximum quantum efficiency of PSII photochemistry (F(v)/F(m)) in rice plants, while Si application significantly increased photosynthetic rate (Pr), transpiration rate (Tr), F(v)/F(0), and F(v)/F(m) of rice plants under drought stress. In addition, water stress increased K, Na, Ca, Mg, Fe content of rice plants, but Si treatment significantly reduced these nutrient level. These results suggested that silicon application was useful to increase drought resistance of rice through the enhancement of photochemical efficiency and adjustment of the mineral nutrient absorption in rice plants.

  5. Effects of exogenous plant growth regulator abscisic acid-induced resistance in rice on the expression of vitellogenin mRNA in Nilaparvata lugens (Hemiptera: Delphacidae) adult females.

    Science.gov (United States)

    Liu, Jing-Lan; Chen, Xiao; Zhang, Hong-Mei; Yang, Xia; Wong, Andrew

    2014-01-01

    Recent study showed that exogenous abscisic acid (ABA) acts as a regulator of plant resistance. This study investigated average injury scale and callose contents of rice, and vitellogenin (Nlvg) mRNA expression in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) adult females after third instar nymphs fed on exogenous ABA-treated susceptible [Taichung Native one (TN1)] and moderately resistant (IR42) rice cultivars. The results showed that exogenous ABA significantly decreased average injury scale of rice and Nlvg mRNA expression in N. lugens adults compared with the control (without ABA spraying). Nlvg mRNA expression in N. lugens adults decreased significantly after third instar nymphs fed on ABA-treated (5, 20, and 40 mg/liter) TN1 for 1 and 2 d, and for IR42, after fed on ABA-treated (20 and 40 mg/liter) rice plants for 1 d and after fed on ABA-treated (5, 20, and 40 mg/liter) rice for 2 d decreased significantly. The callose contents showed no significant change for TN1, while for IR42, significantly increased in roots and sheathes after N. lugens infestation under ABA treatments (20 and 40 mg/liter) compared with the control. The decrease of Nlvg mRNA expression may be partially attributed to the increase of callose content of plants. The results provide a profile for concerning the effects of ABA-induced rice plants' defenses on phloem-feeding insects.

  6. Elite Indica transgenic rice plants expressing modified Cry1Ac endotoxin of Bacillus thuringiensis show enhanced resistance to yellow stem borer (Scirpophaga incertulas).

    Science.gov (United States)

    Khanna, H K; Raina, S K

    2002-08-01

    Bt-transgenics of elite indica rice breeding lines (IR-64, Pusa Basmati-1 and Karnal Local) were generated through biolistic or Agrobacterium-mediated approaches. A synthetic cry1Ac gene, codon optimised for rice and driven by the maize ubiquitin-1 promoter, was used. Over 200 putative transformants of IR-64 and Pusa Basmati-1 and 26 of the Karnal Local were regenerated following use of the hpt (hygromycin phosphotransferase) selection system. Initial transformation frequency was in the range of 1 to 2% for particle bombardment while it was comparatively higher (approximately 9%) for Agrobacterium. An improved selection procedure, involving longer selection on the antibiotic-supplemented medium, enhanced the frequency of Bt-transformants and reduced the number of escapes. Molecular evaluation revealed multiple transgene insertions in transformants, whether generated through biolistic or Agrobacterium. In the latter case, it was also observed that all genes on the T-DNA do not necessarily get transferred as an intact insert. Selected Bt-lines of IR-64 and Pusa Basmati-1, having Bt-titers of 0.1% (of total soluble protein) and above were evaluated for resistance against manual infestation of freshly hatched neonate larvae of yellow stem borers collected from a hot spot stem borer infested area in northern India. Several Bt-lines were identified showing 100% mortality of larvae, within 4-days of infestation, in cut-stem as well as vegetative stage whole plant assays. However, there was an occasional white head even among such plants when assayed at the reproductive stage. Results are discussed in the light of resistance management strategies for deployment of Bt-rice.

  7. Effect of sowing dates and planting density on the infestation of onion maggot (Delia alliaria fonseca in onion (Allium cepa L. crops

    Directory of Open Access Journals (Sweden)

    Feryal B. Hermize

    2015-04-01

    Full Text Available Onion maggot (Delia alliaria Fonseca is an important pest of onion in Iraq, it is responsible for causing serious quantitative and qualitative losses to the onion crops. Nursery and field studies were conducted at college of Agriculture, Abu Ghraib, Iraq to evaluate the effects of sowing date and plant density on onion infestation with onion maggot. Onion seeds were sowing in nursery at three dates viz 5th & 20th September and 3rd October, 2010 with two plants density i.e. 10seed/2m² and 15 seeds /2m². From Nursery, the plants were transplanted to the field at three dates viz 14th & 24th December, 2010 and 3rd January, 2011 with two density i.e. 10seed/2m² and 15 seeds /2m2 with 10 cm and 6 cm plant spacing. Result of the study showed that the lowest infestation of onion maggot was manifested at the lower plants density and first date of cultivation at both nursery and field level. At nursery level 6.16, 6.83 and 7.50 % infestation was reported for three dates of showing respectively at 10g seeds / 2 m² while this infestation was 8.61, 7.50 and 11.5 % respectively for the three sowing dates at 15 g/2 m² densities. Similar types of results were reported in the field study but with slightly higher infestation, here 8.81, 12.54 and 14.04 % infestation was reported on the three plantings dates at 10 cm plant spacing respectively while this infestation was much higher 12.13, 16.81 and 19.04 % respectively for three sowing dates on the 6 cm plant spacing. Higher yield was obtained from the plants of the 1st date of sowing for both the plant densities with best quality. The mean bulb weights were 252.90, 228.30 and 172.00g for the plants growing at 10 cm spacing while this weights was 213.5 , 167.0 and 153.7 g for the plants growing at 6 cm spacing for all the three dates of cultivation respectively. Results of the study revealed that cultivation onion at early date with suitable spaces between the plants may be promising to manage the infestation

  8. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    OpenAIRE

    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...

  9. Overexpression of potassium channel genes in rice plant

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    China′ s potassium fertilizer mainly depends on import and the utilization efficiency of K fertilizer was only 30% . So it is very important to enhance utilization efficiency and to reduce its applying amount by improving nutrition characteristics of plant with bioengineering techinques. Potassium channel genes AKT1 and KAT1 were the genes involved in K+ uptake. To investigate the role of heterogeneous K channel genes in the enhancement of K absorbing, genes AKT1 and KAT1 were transferred into four rice varieties, i.e. Zhonghua 8, Zhonghua 9, Zhonghua 13, and 8706.

  10. The influence of plant mulches on the content of phenolic compounds in soil and primary weed infestation of maize

    Directory of Open Access Journals (Sweden)

    Agnieszka Stokłosa

    2012-12-01

    Full Text Available In growing maize, an increase in the content of phenolic compounds and selected phenolic acids in soil was found after the incorporation of white mustard, buckwheat, spring barley, oats and rye mulches into the soil. The highest content of phenolic compounds in soil was found after oats mulch incorporation (20% more than in the control soil. The highest content of selected phenolic acids was found for the soil with the oats and rye mulch. Among the phenolic acids investigated, ferulic acid was most commonly found in the soil with the plant mulches. However, two phenolic acids: the protocatechuic and chlorogenic acid, were not detected in any soil samples (neither in the control soil nor in the mulched soil. At the same time, a decrease in the primary weed infestation level in maize was found in the plots with all the applied plant mulches, especially on the plots with oats, barley and mustard. The plant mulches were more inhibitory against monocotyledonous weeds than dicotyledonous ones. During high precipitation events and wet weather, a rapid decrease in the content of phenolic compounds in soil and an increase in the primary weed infestation level in maize were observed.

  11. Effect of Nitrogen on Water Content, Sap Flow, and Tolerance of Rice Plants to Brown Planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    LuZhong-xian; S.VILLAREAL; YuXiao-ping; K.L.HEONG; HuCui

    2004-01-01

    Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthopper (BPH), Nilaparvata lugens were determincd in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research institute (1RRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the in crease of nitrogen content inrice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury, of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility' to BPH damage on rice plants applied with nitrogen fertilizer

  12. Genetic evidence for natural product-mediated plant-plant allelopathy in rice (Oryza sativa).

    Science.gov (United States)

    Xu, Meimei; Galhano, Rita; Wiemann, Philipp; Bueno, Emilio; Tiernan, Mollie; Wu, William; Chung, Ill-Min; Gershenzon, Jonathan; Tudzynski, Bettina; Sesma, Ane; Peters, Reuben J

    2012-02-01

    • There is controversy as to whether specific natural products play a role in directly mediating antagonistic plant-plant interactions - that is, allelopathy. If proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza sativa). • However, while substantiated by the presence of phytotoxic compounds at potentially relevant concentrations, demonstrating a direct role for specific natural products in allelopathy has been difficult because of the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied. • The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock-outs of the relevant diterpene synthases (copalyl diphosphate synthase 4 (OsCPS4) and kaurene synthase-like 4 (OsKSL4)), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (Echinochloa crus-galli). • Thus, our results not only provide novel genetic evidence for natural product-mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  13. Effect of Cultural Measures on Nutrient Contents in Rice Plants with Erect Panicles

    Institute of Scientific and Technical Information of China (English)

    WANGBOLUN; ZOUBANGJItffu

    1999-01-01

    Field experiments were carried out with rice variety of Shenong 91 of short culms and erect panicles to study nutrient contents in high-yiedlding rice plants and to increase rice yield by appropriate fertilization.Nitrogen,phosphorus,potassium,magnesium,zinc,manganese,iron and copper contents in rice plants varied with different treatment factors.The relationship between the nutrient contents and treatment factors could be simulated using a multiple quadratic equation.The nutrient contents in plants should be appropriate for high-yielding rice.If the mean nutrient content in rice plants producuing 11 t ha-1 or more of grain (uj) was set as the standard value and the standard deviation (σj) was set as the range of variation,the nutrient content in high-yielding rice plants should be μj±1.99σj.Rice leaves were sensitive to the nutrient elements.Heavy nitrogen dressing increased the content of nitrogen in rice plants.Sparse transplanting also increased nitrogen content,Improper application of nitrogen,phosphorus and potassium could affect the nutrient contents and decrease the grain yield.

  14. Impact of plant growth-promoting rhizobacteria and natural enemies on Myzus persicae (Hemiptera: Aphididae) infestations in pepper.

    Science.gov (United States)

    Boutard-Hunt, Caroline; Smart, Christine D; Thaler, Jennifer; Nault, Brian A

    2009-12-01

    Management of green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), in bell pepper, Capsicum annuum L., was explored through a combination of plant growth-promoting rhizobacteria (PGPR) and endemic biological control in New York in 2006 and 2007. We hypothesized that by using PGPR-treated peppers 1) M. persicae infestations would be reduced via induced resistance, 2) natural enemies would be lured to plants through the elicitation of volatile organic compounds, and 3) yield amount and quality would be improved. Pepper seed was planted in soil containing the PGPR formulation BioYield or untreated soil. Plants were transplanted to field plots and then treated with an insecticide regimen designed to remove or conserve populations of natural enemies. Apterous aphids and natural enemies were counted weekly on plants and pepper fruit were harvested, graded and weighed three times. PGPR did not directly or indirectly reduce aphid densities in either year. In 2006, there were more natural enemies in PGPR-treated plots than untreated ones, but this was probably a density-dependent response to aphid densities rather than a response of natural enemies to volatiles from PGPR-treated plants. For the first harvest date in 2006, yield of all fruit grades, especially the premium Fancy Grade, was 1.7-2.3 times greater in PGPR-treated plots than in untreated plots. However, no differences in yield were observed for the other two harvest dates or overall yield in 2006; no differences in yield among treatments were detected in 2007. Our results suggest that PGPR will not significantly impact M. persicae infestations or natural enemy populations but could enhance yield and quality of pepper fruit in some years.

  15. IMPACT OF ROW-PLANTING ADOPTION ON PRODUCTIVITY OF RICE FARMING IN NORTHERN GHANA

    Directory of Open Access Journals (Sweden)

    Emmanuel DONKOR

    2016-11-01

    Full Text Available This paper employed the endogenous switching regression and propensity score matching methods to analyse the impact of row-planting technology on rice productivity using 470 rice farms in Northern Ghana. The empirical findings showed that the adoption of row-planting technology exerted greater positive impact on rice yields of smallholder farmers. In addition, rice yields of adopters and non-adopters are driven by farm inputs, socioeconomic, institutional and technological factors. We suggest that achieving self-sufficiency in rice and rural economic transformation in sub-Saharan Africa requires promotion of agricultural technologies including row-planting. Different specific policy interventions are also required to promote rice yields for adopters and non-adopters.

  16. Arsenic in rice agrosystems (water, soil and rice plants) in Guayas and Los Ríos provinces, Ecuador.

    Science.gov (United States)

    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 80%) in all parts of the rice plants. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Logistics of supplying biomass from a mountain pine beetle-infested forest to a power plant in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, Mohammadhossein; Sowlati, Taraneh (Depts. of Wood Science, Univ. of British Columbia, Vancouver (Canada)); Sokhansanj, Shahab (Chemical and Biological Engineering, Univ. of British Columbia, Vancouver (Canada))

    2009-03-15

    The search for alternative energy sources has increased the interest in forest biomass. During the past few years, the severe infestation of the mountain pine beetle (MPB) within the forests of interior British Columbia (BC) has led to huge volumes of dead wood that exceed the capacity of the lumber industry. One way to make the most value of the surplus wood is to use it as the feedstock for bioenergy. The high costs associated with harvest and transport, and uncertainty in supply logistics are issues related to forest biomass utilization. This paper presents the development of a forest biomass supply logistics simulation model and its application to a case of supplying MPB-killed biomass from Quesnel timber supply area (one of the most infested areas in the interior BC) to a potential 300 MW power plant adjacent to the city of Quesnel. It provides values of quantity, cost and moisture content of biomass which are important factors in feasibility study of bioenergy projects. In the case of a conventional harvesting system, the biomass recovered from roadside residues in 1 year will meet only about 30% of the annual demand of the power plant with an estimated delivered cost of Can $45 per oven-dry tonne of woodchips. Sensitivity analyses were also performed

  18. Weed infestation in canopy of spring barley in condition of different tillage systems and fertilization and plant protection levels

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The purpose of this work was to determine the influence of conventional tillage (fall ploughing at 25 cm and minimum tillage systems (chisel ploughing at 30 cm and two differentiated fertilization and plant protection levels on number, species composition and air dry weed mass in spring barley cv. Rataj. This spring barley was cultivated in crop rotation potato - spring barley - winter rye. The analysis of field infestation was made prior to spring barley harvest with quantitative- weighting method. There was estimated number of weeds, weed species composition and air dry weight of weeds in two randomly chosen areas of each plot of 0.5 m2. The density of weeds and weed air dry weight was statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05. Intensive level of fertilization and chemical crop protection decreased number of monocotyledonous weeds and total weeds in canopy of spring barley. Conventional system of soil cultivation decreased in a canopy of spring barley the following species of weeds: Geranium pusillum, Galinsoga parviflora, Stellaria media, Apera spica-venti, Poa annua and Echinochloa crusgalli. Conventional tillage increases number of Chamomilla suaveolens and Fallopia convolvulus in a canopy of spring barley. Intensive fertilization and plant protection levels decreased weed infestation first of all through Echinochloa crusgalli, Apera spica-venti, Fallopia convolvulus, Galinsoga parviflora, Geranium pusillum, Chenopodium album and Setaria pumila.

  19. Zebra chip disease incidence on potato is influenced by timing of potato psyllid infestation,but not by the host plants on which they were reared

    Institute of Scientific and Technical Information of China (English)

    Feng Gao; John Jifon; Xiangbing Yang; Tong-Xian Liu

    2009-01-01

    The Zebra chip (ZC) syndrome is an emerging disease of potato and a major threat to the potato industry.The potato psyllid,Bactericerca cockerelli (Sulc) is believed to be a vector of the ZC pathogen,which is now thought to be Candidatus Liberibacter,a bacterium.To further understand the relationship between potato psyllid infestation and ZC disease expression,healthy potato plants at different growth stages (4,6 and 10 weeks after germination) were exposed separately to potato psyllids that were separately reared on four solanaceons hosts plants (potato,tomato,eggplant or bell pepper) for more than 1 year.ZC symptoms,leaf rates and total nonstructural carbohydrate accumulation in leaves and tubers of healthy and psyllid-infested plants were monitored and recorded.Typical ZC symptoms were observed in leaves and tubers of all plants exposed to potato psyllids regardless of the host plant on which they were reared.This was also accompanied by significant reductions in net photosynthetic rate.Caged potato plants without exposure to potato psyllids (uninfested controls) did not show any ZC symptom in both foliage and in harvested tubers.Foliage damage and ZC expression were most severe in the potato plants that were exposed to potato psyllids 4 weeks after germination compared to plants infested at later growth stages.Tubers from potato psyllid-infested plants had significantly higher levels of reducing sugars (glucose) and lower levels of starch than those in healthy plants,indicating that potato psyllid infestation interfered with carbohydrate metabolism in either leaves or tubers,resulting in ZC expression.

  20. Establishment of a Gene Expression System in Rice Chloroplast and Obtainment of PPT-Resistant Rice Plants

    Institute of Scientific and Technical Information of China (English)

    LI Yi-nü; SUN Bing-yao; SU Ning; MENG Xiang-xun; ZHANG Zhi-fang; SHEN Gui-fang

    2009-01-01

    In contrast to the situation of random integration of foreign genes in nuclear transformation,the introduction of genes via chloroplast genetic engineering is characterized by site-specific pattern via homologous recombination.To establish an expression system for alien genes in rice chloroplast,the intergenic region of ndhF and trnL was selected as target for sitespecific integration of PPT-resistant bar gene in this study.Two DNA fragments suitable for homologous recombination were cloned from rice chloroplast genome DNA using PCR technique,and the chloroplast-specific expression vector pRB was constructed by fusing a modified 16S rRNA gene promoter to bar gene together with terminator of psbA gene 3'sequence.Chloroplast transformation was carried out by biolistic bombardment of sterile rice calli with the pRB construct.Subsequently,the regenerated plantlets and seeds of progeny arising from reciprocal cross to the wild-type lines were obtained.Molecular analysis suggested that the bar gene has been integrated into rice chloroplast genome.Genetic analysis revealed that bar gene could be transmitted and expressed normally in chloroplast genome.Thus,the bar gene conferred not only selection pressure for the transformation of rice chloroplast genome,but PPT-resistant trait for rice plants as well.It is suggested that an efficient gene expression system in the rice chloroplast has been established by chloroplast transformation technique.

  1. Members of Gammaproteobacteria as indicator species of healthy banana plants on Fusarium wilt-infested fields in Central America

    Science.gov (United States)

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2017-01-01

    Culminating in the 1950’s, bananas, the world’s most extensive perennial monoculture, suffered one of the most devastating disease epidemics in history. In Latin America and the Caribbean, Fusarium wilt (FW) caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC), forced the abandonment of the Gros Michel-based export banana industry. Comparative microbiome analyses performed between healthy and diseased Gros Michel plants on FW-infested farms in Nicaragua and Costa Rica revealed significant shifts in the gammaproteobacterial microbiome. Although we found substantial differences in the banana microbiome between both countries and a higher impact of FOC on farms in Costa Rica than in Nicaragua, the composition especially in the endophytic microhabitats was similar and the general microbiome response to FW followed similar rules. Gammaproteobacterial diversity and community members were identified as potential health indicators. Healthy plants revealed an increase in potentially plant-beneficial Pseudomonas and Stenotrophomonas, while diseased plants showed a preferential occurrence of Enterobacteriaceae known for their plant-degrading capacity. Significantly higher microbial rhizosphere diversity found in healthy plants could be indicative of pathogen suppression events preventing or minimizing disease expression. This first study examining banana microbiome shifts caused by FW under natural field conditions opens new perspectives for its biological control. PMID:28345666

  2. Effect of seaweed extracts on growth and yield of rice plants

    Directory of Open Access Journals (Sweden)

    ALUH NIKMATULLAH

    2010-07-01

    Full Text Available Sunarpi, Jupri A, Kurnianingsih R, Julisaniah NI, Nikmatullah A 2010. Effect of seaweed extracts on growth and yield of rice plants. Nusantara Bioscience 2: 73-77. Application of liquid seaweed fertilizers on some plant specieshas been reported to decrease application doses of nitrogen, phosphorus and potassium on some crop plants, as well as stimulating growth and production of many plants. It has been reported that there are at least 59 species of seaweeds found in coastal zone of West Nusa Tenggara Province, 15 of those species weres able to stimulate germination, growth and production of some horticultural and legume plants. The aim of this research is to investigate the effect of seaweed extracts obtained from ten species on growth and production of rice plants. To achive the goal, seaweed (100 g per species wasextracted with 100 mL of water, to obtain the concentration of 100%. Seaweed extract (15% was sprayed into the rice plants during vegetative and generative stages. Subsequently, the growth and yield parameters of rice plants were measured. The results shown that extracts of Sargassum sp.1, Sargassum sp.2, Sargassum polycistum, Hydroclathrus sp., Turbinaria ornata, and Turbinaria murayana, were able to induce growth of rice plants. However, only the Hydroclathrus sp. extract could enhance both growth and production of rice plants.

  3. Natural Plant Oils and Terpenes as Protector for the Potato Tubers against Phthorimaea operculella Infestation by Different Application Methods

    Directory of Open Access Journals (Sweden)

    Aziza Sharaby

    2014-06-01

    Full Text Available For protecting potato tubers from the potato tuber moth (PTM infestation during storage, different concentrations of ten natural plant oils and three commercial monoterpnes were tested, some as fumigants or dusts against adults or dusts against neonate larvae, while others as sprays on the gunny sacks in which potato tubers were stored. Tuber damage indices as well as persistence indices for tested materials were assessed. Vapors of Cymbopogon citratus, Myristica fragrans (nutmag, Mentha citrata and a-Ionone (monoterpene caused a highly significant reductions in the life span of exposed moths as well as in new adult offsprings. Other tested oils as Cinnamonium zeylanicum, Myristica. fragrans (Mace and Pelargonium graveolens caused a insignificant effect. There was no significant effect of the tested vapors on egg hatchability, except in case of oils of C. citratus, M. fragrans (nutmag and M. tragrans(Mace oil which caused high reduction in egg hatchability. According to the values of damage indices, the most effective oil vapors were arranged ascendingly as follows: Myristica (nutmag < Cymbopogon < Mentha < a - Ionone. Dusting potato tubers with 1% conc., (mixed with talcum powder of Myristica, Mentha, Cymbopogons oils and a-Ionone (monoterpene caused high reduction in egg deposition, adult emergence as well as percentage of penetrated larvae of PTM. According to their damage indices, Cymbopogon and ά-Ionone were the most protective oils, followed by Myristica and Mentha. Spraying gunnysacks with 1% conc., of the aforementioned natural oils separately elicited high reduction in PTM progeny; while their combinations did not elicit any significant synergistic effect. According to their tuber damage indices, it was found that Cymbopogon oil alone or mixed with Myristica oil showed the best protective effect, followed by Myristica oil alone and Mentha oil mixed with Cymbopogon oil. Assessment of the persistence index of various tested materials

  4. Contribution of Iron Phosphate in Calcareous Paddy Soils to Phosphorus Nutrition of Rice Plant

    Institute of Scientific and Technical Information of China (English)

    GUOZHI-FEN; TUSHU-XIN; 等

    1995-01-01

    A study was carried out on contribution of iron phosphate to phosphorus nutrition of rice plant under waterlogged and moist conditions,respectively,by use of synthetic Fe32 PO4.nH2O,tagging directly the iron phophate in calcareous paddy soils.Results showed that under waterlogged condition,similar to iron phosphate in acidic paddy soils.that in clacareous paddy soils was an important source of phosphorus to rice plant ,and the amount of phosphorus originated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.

  5. Evaluating leaf and canopy reflectance of stressed rice plants to monitor arsenic contamination

    Science.gov (United States)

    Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor ars...

  6. Expression activity of the CpTI gene in transgenic rice plants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Plant harboured protease inhibitor is a part of the natural plant defense system against insect predation. Plants transformed with foreign plant protease inhibitor genes can enhance resistance to insect pests. So far, at least 20 kinds of plants, including tobacco, rice, tomato, cotton et al., have been transformed with various plant protease inhibitor genes. We have transformed rice with CpTI (cowpea trypsin inhibitor) gene. To assess the range and stability of expression of the CpTI gene, CpTI protein activities were determined in various tissues and at different development stages of transgenic inbred lines.

  7. Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

    Institute of Scientific and Technical Information of China (English)

    Malay Kumar ADAK; Nirmalya GHOSH; Dilip Kumar DASGUPTA; Sudha GUPTA

    2011-01-01

    The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation.It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield.The detrimental effects of the complete submergence were recorded in generation of sucrose,starch,sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e.non-submerged) condition.The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity.Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity.However,under normal or control condition,there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity.Still,photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield.Finally,plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues.It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles,in this case) as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

  8. Non-Indigenous Plants in the Northern Great Plains : Ecological Effects of Infestation and Control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Euphorbia esula is a long-lived perennial plant with an extensive root system. The extent of the root system makes the plant highly resistant to most traditional...

  9. Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Eliana Alcantra

    2011-06-01

    Full Text Available Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae. The aphid Aphis gossypii is an insect pest that causes damage mainly at the beginning of the cotton plant development. The effect of resistance inductors silicon and acibenzolar-s-methyl (ASM on the development of colored cotton plants were researched in the presence and absence of A. gossypii. Three colored cotton cultivars were sown in pots and individually infested with 25 apterous aphids, 13 days after the application of the inductors. Fifteen days after plant emergence, the silicon was applied at a dosage equivalent to 3 t/ha and acibenzolar-s-methyl in 0.2% solution of the product BION 500®. After 21 days of infestation the following parameters were evaluated: plant height, stem diameter, dry matter of aerial part and root, and total number of aphids replaced. It was verified that the plant height was reduced in the presence of aphids and all variables were negatively affected by the application of ASM. However, silicon did not affect plant development.

  10. The Effects of Climate Change on the Planting Boundary and Potential Yield for Different Rice Cropping Systems in Southern China

    Institute of Scientific and Technical Information of China (English)

    YE Qing; YANG Xiao-guang; LIU Zhi-juan; DAI Shu-wei; LI Yong; XIE Wen-juan; CHEN Fu

    2014-01-01

    Based on climate data from 254 meteorological stations, this study estimated the effects of climate change on rice planting boundaries and potential yields in the southern China during 1951-2010. The results indicated a signiifcant northward shift and westward expansion of northern boundaries for rice planting in the southern China. Compared with the period of 1951-1980, the average temperature during rice growing season in the period of 1981-2010 increased by 0.4°C, and the northern planting boundaries for single rice cropping system (SRCS), early triple cropping rice system (ETCRS), medium triple cropping rice system (MTCRS), and late triple cropping rice system (LTCRS) moved northward by 10, 30, 52 and 66 km, respectively. In addition, compared with the period of 1951-1980, the suitable planting area for SRCS was reduced by 11%during the period of 1981-2010. However, the suitable planting areas for other rice cropping systems increased, with the increasing amplitude of 3, 8, and 10%for ETCRS, MTCRS and LTCRS, respectively. In general, the light and temperature potential productivity of rice decreased by 2.5%. Without considering the change of rice cultivars, the northern planting boundaries for different rice cropping systems showed a northward shift tendency. Climate change resulted in decrease of per unit area yield for SRCS and the annual average yields of ETCRS and LTCRS. Nevertheless, the overall rice production in the entire research area showed a decreasing trend even with the increasing trend of annual average yield for MTCRS.

  11. Sago-Type Palms Were an Important Plant Food Prior to Rice in Southern Subtropical China

    OpenAIRE

    Xiaoyan Yang; Barton, Huw J.; Zhiwei Wan; Quan Li; Zhikun Ma; Mingqi Li; Dan Zhang; Jun Wei

    2013-01-01

    Poor preservation of plant macroremains in the acid soils of southern subtropical China has hampered understanding of prehistoric diets in the region and of the spread of domesticated rice southwards from the Yangtze River region. According to records in ancient books and archaeological discoveries from historical sites, it is presumed that roots and tubers were the staple plant foods in this region before rice agriculture was widely practiced. But no direct evidences provided to test the hyp...

  12. Transgenic rice plants expressing cry1Ia5 gene are resistant to stem borer (Chilo agamemnon).

    Science.gov (United States)

    Moghaieb, Reda E A

    2010-01-01

    The stem borer, Chilo agamemnon Bles., is the most serious insect pest in rice fields of the Egyptian Nile Delta. To induce rice plant resistance to Chilo agamemnon, the cry1Ia5 gene was introduced to rice plants (Oryza sativa L.). The integration of the cry1Ia5 gene into the plant genome was confirmed using PCR and Southern blot analyses. The obtained plantlets were transferred to the greenhouse until seeds were collected. Northern blot analysis of the T1 plants confirmed the expression of the cry1Ia5 gene. The insecticidal activity of the transgenic plants against the rice stem borer Chilo agamemnon were tested. The third larval instars were fed on stem cuts from three transgenic lines (L1, L2 and L3) as well as cuts from the control (gfp-transgenic) plants for one week and the mortality percentage was daily recorded. Transgenic line-3 showed the highest mortality percentage after one day (50%) followed by L2 (25%) then L1 (0%). Two days post treatment the mortality percentage increased to 70, 45 and 25% for transgenic lines 1, 2 and 3 respectively. Mortality of 100% was recorded four days post treatment, while those fed on the gfp-transgenic rice (control) showed 0% mortality. Thus, transgenic plants showed high resistance to stem borers and can serve as a novel genetic resource in breeding programs. Transgenic plants expressing BT protein were normal in phenotype with as good seed setting as the nontransgenic control plants.

  13. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    Directory of Open Access Journals (Sweden)

    Maria Lígia de Souza Silva

    2014-04-01

    Full Text Available 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 responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

  14. Rhizobacterial colonization of roots modulates plant volatile emission and enhances the attraction of a parasitoid wasp to host-infested plants.

    Science.gov (United States)

    Pangesti, Nurmi; Weldegergis, Berhane T; Langendorf, Benjamin; van Loon, Joop J A; Dicke, Marcel; Pineda, Ana

    2015-08-01

    Beneficial root-associated microbes modify the physiological status of their host plants and affect direct and indirect plant defense against insect herbivores. While the effects of these microbes on direct plant defense against insect herbivores are well described, knowledge of the effect of the microbes on indirect plant defense against insect herbivores is still limited. In this study, we evaluate the role of the rhizobacterium Pseudomonas fluorescens WCS417r in indirect plant defense against the generalist leaf-chewing insect Mamestra brassicae through a combination of behavioral, chemical, and gene-transcriptional approaches. We show that rhizobacterial colonization of Arabidopsis thaliana roots results in an increased attraction of the parasitoid Microplitis mediator to caterpillar-infested plants. Volatile analysis revealed that rhizobacterial colonization suppressed the emission of the terpene (E)-α-bergamotene and the aromatics methyl salicylate and lilial in response to caterpillar feeding. Rhizobacterial colonization decreased the caterpillar-induced transcription of the terpene synthase genes TPS03 and TPS04. Rhizobacteria enhanced both the growth and the indirect defense of plants under caterpillar attack. This study shows that rhizobacteria have a high potential to enhance the biocontrol of leaf-chewing herbivores based on enhanced attraction of parasitoids.

  15. Elevated O₃ enhances the attraction of whitefly-infested tomato plants to Encarsia formosa.

    Science.gov (United States)

    Cui, Hongying; Su, Jianwei; Wei, Jianing; Hu, Yongjian; Ge, Feng

    2014-06-18

    We experimentally examined the effects of elevated O₃ and whitefly herbivory on tomato volatiles, feeding and oviposition preferences of whiteflies and behavioural responses of Encarsia formosa to these emissions on two tomato genotypes, a wild-type (Wt) and a jasmonic acid (JA) defence-enhanced genotype (JA-OE, 35S). The O₃ level and whitefly herbivory significantly increased the total amount of volatile organic compounds (VOCs), monoterpenes, green leaf volatiles (GLVs), and aldehyde volatiles produced by tomato plants. The 35S plants released higher amount of total VOCs and monoterpene volatiles than Wt plants under O₃+herbivory treatments. The feeding and oviposition bioassays showed that control plants were preferred by adult whiteflies whereas the 35S plants were not preferred by whiteflies. In the Y-tube tests, O₃+herbivory treatment genotypes were preferred by adult E. Formosa. The 35S plants were preferred by adult E. formosa under O₃, herbivory and O₃+herbivory treatments. Our results demonstrated that elevated O₃ and whitefly herbivory significantly increased tomato volatiles, which attracted E. formosa and reduced whitefly feeding. The 35S plants had a higher resistance to B. tabaci than Wt plant. Such changes suggest that the direct and indirect defences of resistant genotypes, such as 35S, could strengthen as the atmospheric O₃ concentration increases.

  16. Rice straw addition as sawdust substitution in oyster mushroom (Pleurotus ostreatus) planted media

    Science.gov (United States)

    Utami, Christine Pamardining; Susilawati, Puspita Ratna

    2017-08-01

    Oyster mushroom is favorite by the people because of the high nutrients. The oyster mushroom cultivation usually using sawdust. The availability of sawdust become difficult to find. It makes difficulties of mushroom cultivation. Rice straw as an agricultural waste can be used as planted media of oyster mushroom because they contain much nutrition needed to the mushroom growth. The aims of this research were to analysis the influence of rice straw addition in a baglog as planted media and to analysis the concentration of rice straw addition which can substitute sawdust in planted media of oyster mushroom. This research used 4 treatment of sawdust and rice straw ratio K = 75 % : 0 %, P1 = 60 % : 15 %, P2 = 40 % : 35 %, P3 = 15 % : 60 %. The same material composition of all baglog was bran 20%, chalk 5%, and water 70%. The parameters used in this research were wet weight, dry weight, moisture content and number of the mushroom fruit body. Data analysis was used ANOVA test with 1 factorial. The results of this research based on statistical analysis showed that there was no influence of rice straw addition in a planted media on the oyster mushroomgrowth. 15% : 60% was the concentrationof rice straw additionwhich can substitute the sawdust in planted media of oyster mushroom.

  17. Deciphering the factors associated with the colonization of rice plants by cyanobacteria.

    Science.gov (United States)

    Bidyarani, Ngangom; Prasanna, Radha; Chawla, Gautam; Babu, Santosh; Singh, Rajendra

    2015-04-01

    Cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. The activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ARA), and DNA fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. Microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and shoot tissues. Among the six cyanobacterial strains employed, Calothrix sp. (RPC1), Anabaena laxa (RPAN8), and Anabaena azollae (C16) were the best performing strains, in terms of colonization in roots and stem. These strains also enhanced nitrogen fixation and stimulated the activity of plant defense/cell wall-degrading enzymes. A significantly high correlation was also recorded between the elicited plant enzymes, growth, and ARA. DNA fingerprinting using highly iterated palindromic sequences (HIP-TG) further helped in proving the establishment of inoculated organisms in the roots/shoots of rice plants. This study illustrated that the colonization of cyanobacteria in the plant tissues is facilitated by increased elicitation of plant enzymes, leading to improved plant growth, nutrient mobilization, and enhanced plant fitness. Such strains can be promising candidates for developing "cyanobacteria colonized-nitrogen-fixing rice plants" in the future.

  18. Understanding cross-communication between aboveground and belowground tissues via transcriptome analysis of a sucking insect whitefly-infested pepper plants.

    Science.gov (United States)

    Park, Yong-Soon; Ryu, Choong-Min

    2014-01-03

    Plants have developed defensive machinery to protect themselves against herbivore and pathogen attacks. We previously reported that aboveground whitefly (Bemisia tabaci Genn.) infestation elicited induced resistance in leaves and roots and influenced the modification of the rhizosphere microflora. In this study, to obtain molecular evidence supporting these plant fitness strategies against whitefly infestation, we performed a 300 K pepper microarray analysis using leaf and root tissues of pepper (Capsicum annuum L.) applied with whitefly, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), and the combination of BTH+whitefly. We defined differentially expressed genes (DEGs) as genes exhibiting more than 2-fold change (1.0 based on log2 values) in expression in leaves and roots in response to each treatment compared to the control. We identified a total of 16,188 DEGs in leaves and roots. Of these, 6685, 6752, and 4045 DEGs from leaf tissue and 6768, 7705, and 7667 DEGs from root tissue were identified in the BTH, BTH+whitefly, and whitefly treatment groups, respectively. The total number of DEGs was approximately two-times higher in roots than in whitefly-infested leaves subjected to whitefly infestation. Among DEGs, whitefly feeding induced salicylic acid and jasmonic acid/ethylene-dependent signaling pathways in leaves and roots. Several transporters and auxin-responsive genes were upregulated in roots, which can explain why biomass increase is facilitated. Using transcriptome analysis, our study provides new insights into the molecular basis of whitefly-mediated intercommunication between aboveground and belowground plant tissues and provides molecular evidence that may explain the alteration of rhizosphere microflora and root biomass by whitefly infestation.

  19. Ascending migration of endophytic rhizobia, from roots to leaves, inside rice plants and assessment of benefits to rice growth physiology.

    Science.gov (United States)

    Chi, Feng; Shen, Shi-Hua; Cheng, Hai-Ping; Jing, Yu-Xiang; Yanni, Youssef G; Dazzo, Frank B

    2005-11-01

    Rhizobia, the root-nodule endosymbionts of leguminous plants, also form natural endophytic associations with roots of important cereal plants. Despite its widespread occurrence, much remains unknown about colonization of cereals by rhizobia. We examined the infection, dissemination, and colonization of healthy rice plant tissues by four species of gfp-tagged rhizobia and their influence on the growth physiology of rice. The results indicated a dynamic infection process beginning with surface colonization of the rhizoplane (especially at lateral root emergence), followed by endophytic colonization within roots, and then ascending endophytic migration into the stem base, leaf sheath, and leaves where they developed high populations. In situ CMEIAS image analysis indicated local endophytic population densities reaching as high as 9 x 10(10) rhizobia per cm3 of infected host tissues, whereas plating experiments indicated rapid, transient or persistent growth depending on the rhizobial strain and rice tissue examined. Rice plants inoculated with certain test strains of gfp-tagged rhizobia produced significantly higher root and shoot biomass; increased their photosynthetic rate, stomatal conductance, transpiration velocity, water utilization efficiency, and flag leaf area (considered to possess the highest photosynthetic activity); and accumulated higher levels of indoleacetic acid and gibberellin growth-regulating phytohormones. Considered collectively, the results indicate that this endophytic plant-bacterium association is far more inclusive, invasive, and dynamic than previously thought, including dissemination in both below-ground and above-ground tissues and enhancement of growth physiology by several rhizobial species, therefore heightening its interest and potential value as a biofertilizer strategy for sustainable agriculture to produce the world's most important cereal crops.

  20. Impact of planting date on sunflower beetle (Coleoptera: Chrysomelidae) infestation, damage, and parasitism in cultivated sunflower.

    Science.gov (United States)

    Charlet, Laurence D; Knodel, Janet J

    2003-06-01

    The sunflower beetle, Zygogramma exclamationis (F.), is the major defoliating pest of sunflower (Helianthus annuus L.). Planting date was evaluated as a potential management tool in a variety of production regions throughout North Dakota from 1997 to 1999, for its impact on sunflower beetle population density of both adults and larvae, defoliation caused by both feeding stages, seed yield, oil content, and larval parasitism in cultivated sunflower. Results from this 3-yr study revealed that sunflower beetle adult and larval populations decreased as planting date was delayed. Delayed planting also reduced defoliation from adult and larval feeding, which is consistent with the lower numbers of the beetles present in the later seeded plots. Even a planting delay of only 1 wk was sufficient to significantly reduce feeding damage to the sunflower plant. Yield reduction caused by leaf destruction of the sunflower beetle adults and larvae was clearly evident in the first year of the study. The other component of sunflower yield, oil content, did not appear to be influenced by beetle feeding. The tachinid parasitoid, Myiopharus macellus (Rheinhard), appeared to be a significant mortality factor of sunflower beetle larvae at most locations regardless of the dates of planting, and was able to attack and parasitize the beetle at various larval densities. The results of this investigation showed the potential of delayed planting date as an effective integrated pest management tactic to reduce sunflower beetle adults, larvae, and their resulting defoliation. In addition, altering planting dates was compatible with biological control of the beetle, because delaying the planting date did not reduce the effectiveness of the parasitic fly, M. macellus, which attacks the sunflower beetle larvae.

  1. Herbicide resistance of transgenic rice plants expressing human CYP1A1.

    Science.gov (United States)

    Kawahigashi, Hiroyuki; Hirose, Sakiko; Ohkawa, Hideo; Ohkawa, Yasunobu

    2007-01-01

    Cytochrome P450 monooxygenases (P450s) metabolize herbicides to produce mainly non-phytotoxic metabolites. Although rice plants endogenously express multiple P450 enzymes, transgenic plants expressing other P450 isoforms might show improved herbicide resistance or reduce herbicide residues. Mammalian P450s metabolizing xenobiotics are reported to show a broad and overlapping substrate specificity towards lipophilic foreign chemicals, including herbicides. These P450s are ideal for enhancing xenobiotic metabolism in plants. A human P450, CYP1A1, metabolizes various herbicides with different structures and modes of herbicide action. We introduced human CYP1A1 into rice plants, and the transgenic rice plants showed broad cross-resistance towards various herbicides and metabolized them. The introduced CYP1A1 enhanced the metabolism of chlorotoluron and norflurazon. The herbicides were metabolized more rapidly in the transgenic rice plants than in non-transgenic controls. Transgenic rice plants expressing P450 might be useful for reducing concentrations of various chemicals in the environment.

  2. Generating of rice OsCENH3-GFP transgenic plants and their genetic applications

    Institute of Scientific and Technical Information of China (English)

    YU HengXiu; WANG Xin; GONG ZhiYun; TANG Ding; GU MingHong; CHENG ZhuKuan

    2008-01-01

    In order to investigate rice functional centromeres, OsCENH3-GFP chimeric gene was constructed and transformed into the indica rice variety, Zhongxian 3037, mediated by Agrobacturium. The integration of the exogenous genes in the transgenic plants was confirmed by PCR and Southern blotting. The transgenic plants grow normally during their whole life time, just like Zhongxian 3037. No significant defects were detected in either mitosis or meiosis of the transgenic plants. The overlapping of GFP signals and anti-CENH3 foci in both mitotic and meiotic cells from To and T1 generation plants indicated that GFP had been successfully fused with CENH3, so the GFP signals can well represent the CENH3 locations on each chromosome. To evaluate the applicability of the transgenic plants to other genetic studies, fluorescence in situ hybridization (FISH) using rice centromeric tandem repetitive sequence CentO as the probe was conducted on the zygotene chromosomes of pollen mother cells (PMCs). It has been revealed that the GFP signals are overlapping with CentO FISH signals, showing that CentO is one of the key elements constituting rice functional centromeres. Immunofluorescent staining using anti-α-tublin antibody and anti-PAIR2 antibody on the chromosomes during mitosis and meiosis stages of the transgenic plants further reveals that OsCENH3-GFP transgenic plants can be widely used for studying rice molecular biology, especially for tagging functional centromeres in both living cells and tissues.

  3. Gas exchange rates, plant height, yield components, and productivity of upland rice as affected by plant regulators

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Félix Alvarez

    2012-10-01

    Full Text Available The objective of this work was to evaluate gas exchange rates, plant height, yield components, and productivity of upland rice, as affected by type and application time of plant growth regulators. A randomized block design, in a 4x2 factorial arrangement, with four replicates was used. Treatments consisted of three growth regulators (mepiquat chloride, trinexapac-ethyl, and paclobutrazol, besides a control treatment applied at two different phenological stages: early tillering or panicle primordial differentiation. The experiment was performed under sprinkler-irrigated field conditions. Net CO2 assimilation, stomatal conductance, plant transpiration, and water-use efficiency were measured four times in Primavera upland rice cultivar, between booting and milky grain phenophases. Gas exchange rates were neither influenced by growth regulators nor by application time. There was, however, interaction between these factors on the other variables. Application of trinexapac-ethyl at both tillering and differentiation stages reduced plant height and negatively affected yield components and rice productivity. However, paclobutrazol and mepiquat chloride applied at tillering, reduced plant height without affecting rice yield. Mepiquat chloride acted as a growth stimulator when applied at the differentiation stage, and significantly increased plant height, panicle number, and grain yield of upland rice.

  4. Uptake of Arsenic in Rice Plant Varieties Cultivated with Arsenic Rich Groundwater

    Directory of Open Access Journals (Sweden)

    Piyal Bhattacharya

    2010-07-01

    Full Text Available Groundwater of many areas of West Bengal, India is severely contaminated with arsenic. The paddy soil gets con¬taminated from the groundwater and thus there is a probability of bioaccumulation of arsenic in rice plants cultivated with arsenic contaminated groundwater and soil. This study aims at assessing the level of arsenic in irrigation water and soil and to investigate the seasonal bioaccumulation of arsenic in the various parts (straw, husk and grain of the rice plant of differ¬ent varieties in the arsenic affected two blocks (Chakdaha and Ranaghat-I of Nadia district, West Bengal. It was found that the arsenic uptake in rice during the pre-monsoon season is more than that of the post-monsoon season. The accumulation of arsenic found to vary with different rice varieties; the maximum accumulation was in White minikit (0.31±0.005 mg/kg and IR 50 (0.29±0.001 mg/kg rice varieties and minimum was found to be in the Jaya rice variety (0.14±0.002 mg/kg. In rice plant maximum arsenic accumulation occurred in the straw part (0.89±0.019-1.65±0.021 mg/kg compared to the ac¬cumulation in husk (0.31±0.011-0.85±0.016 mg/kg and grain (0.14±0.002-0.31±0.005 mg/kg parts. For any rice sample concentration of arsenic in the grain did not exceed the WHO recommended permissible limit in rice (1.0 mg/kg.

  5. Information system of rice planting calendar based on ten-day (Dasarian) rainfall prediction

    Science.gov (United States)

    Susandi, Armi; Tamamadin, Mamad; Djamal, Erizal; Las, Irsal

    2015-09-01

    This paper describes information system of rice planting calendar to help farmers in determining the time for rice planting. The information includes rainfall prediction in ten days (dasarian) scale overlaid to map of rice field to produce map of rice planting in village level. The rainfall prediction was produced by stochastic modeling using Fast Fourier Transform (FFT) and Non-Linier Least Squares methods to fit the curve of function to the rainfall data. In this research, the Fourier series has been modified become non-linear function to follow the recent characteristics of rainfall that is non stationary. The results have been also validated in 4 steps, including R-Square, RMSE, R-Skill, and comparison with field data. The development of information system (cyber extension) provides information such as rainfall prediction, prediction of the planting time, and interactive space for farmers to respond to the information submitted. Interfaces for interactive response will be critical to the improvement of prediction accuracy of information, both rainfall and planting time. The method used to get this information system includes mapping on rice planting prediction, converting the format file, developing database system, developing website, and posting website. Because of this map was overlaid with the Google map, the map files must be converted to the .kml file format.

  6. Information system of rice planting calendar based on ten-day (Dasarian) rainfall prediction

    Energy Technology Data Exchange (ETDEWEB)

    Susandi, Armi, E-mail: armi@meteo.itb.ac.id [Department of Meteorology, Institut Teknologi Bandung, Labtek XI Building floor 1, Jalan Ganesa 10 Bandung 40132 (Indonesia); Tamamadin, Mamad, E-mail: mamadtama@meteo.itb.ac.id [Laboratory of Applied Meteorology, Institut Teknologi Bandung Ged. Labtek XI lt. 1, Jalan Ganesa 10 Bandung 40132 (Indonesia); Djamal, Erizal, E-mail: erizal-jamal@yahoo.com [Center for Agricultural Technology Transfer Management, Ministry of Agriculture Jl. Salak No. 22 Bogor (Indonesia); Las, Irsal, E-mail: irsallas@yahoo.com [Indonesian Agroclimate and Hydrology Research Institute, Ministry of Agriculture Jl. Tentara Pelajar 1a Bogor 16111 (Indonesia)

    2015-09-30

    This paper describes information system of rice planting calendar to help farmers in determining the time for rice planting. The information includes rainfall prediction in ten days (dasarian) scale overlaid to map of rice field to produce map of rice planting in village level. The rainfall prediction was produced by stochastic modeling using Fast Fourier Transform (FFT) and Non-Linier Least Squares methods to fit the curve of function to the rainfall data. In this research, the Fourier series has been modified become non-linear function to follow the recent characteristics of rainfall that is non stationary. The results have been also validated in 4 steps, including R-Square, RMSE, R-Skill, and comparison with field data. The development of information system (cyber extension) provides information such as rainfall prediction, prediction of the planting time, and interactive space for farmers to respond to the information submitted. Interfaces for interactive response will be critical to the improvement of prediction accuracy of information, both rainfall and planting time. The method used to get this information system includes mapping on rice planting prediction, converting the format file, developing database system, developing website, and posting website. Because of this map was overlaid with the Google map, the map files must be converted to the .kml file format.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Plant physiological and soil characteristics associated with methane and nitrous oxide emission from rice paddy

    OpenAIRE

    Baruah, K.K.; Gogoi, Boby; Gogoi, P.

    2010-01-01

    Methane (CH4) and nitrous oxide (N2O) are important greenhouse gases causing global warming and climate change. Efforts were made to analyze the CH4 and N2O flux in relation to plant and soil factors from rice (Oryza sativa L.) paddy. Ten popularly grown rice varieties namely Rashmisali, Bogajoha, Basmuthi, Lalkalamdani, Choimora (traditional varieties); Mahsuri, Moniram, Kushal, Gitesh and Profulla (high yielding varieties = HYV) were grown during monsoon season of July 2006. The CH4 and N2O...

  9. Differential gene expression in whitefly Bemisia tabaci-infested tomato (Solanum lycopersicum) plants at progressing developmental stages of the insect's life cycle.

    Science.gov (United States)

    Estrada-Hernández, María Gloria; Valenzuela-Soto, José Humberto; Ibarra-Laclette, Enrique; Délano-Frier, John Paul

    2009-09-01

    A suppression-subtractive-hybridization (SSH) strategy was used to identify genes whose expression was modified in response to virus-free whitefly Bemisia tabaci (Bt, biotype A) infestation in tomato (Solanum lycopersicum) plants. Thus, forward and reverse SSH gene libraries were generated at four points in the whitefly's life cycle, namely at (1) 2 days (adult feeding and oviposition: phase I); (2) 7 days (mobile crawler stage: phase II); (3) 12 days (second to third instar nymphal transition: phase III) and (4) 18 days (fourth instar nymphal stage: phase IV). The 169 genes with altered expression (up and downregulated) that were identified in the eight generated SSH libraries, together with 75 additional genes that were selected on the basis of their involvement in resistance responses against phytofagous insects and pathogens, were printed on a Nexterion(®) Slide MPX 16 to monitor their pattern of expression at the above phases. The results indicated that Bt infestation in tomato led to distinctive phase-specific expression/repression patterns of several genes associated predominantly with photosynthesis, senescence, secondary metabolism and (a)biotic stress. Most of the gene expression modifications were detected in phase III, coinciding with intense larval feeding, whereas fewer changes were detected in phases I and IV. These results complement previously reported gene expression profiles in Bt-infested tomato and Arabidopisis, and support and expand the opinion that Bt infestation leads to the downregulation of specific defense responses in addition to those controlled by jasmonic acid. Copyright © Physiologia Plantarum 2009.

  10. Ethnobotanical investigation of 'wild' food plants used by rice farmers in Kalasin, Northeast Thailand

    NARCIS (Netherlands)

    Cruz Garcia, G.S.; Price, L.L.

    2011-01-01

    Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as

  11. Ethnobotanical investigation of 'wild' food plants used by rice farmers in Kalasin, Northeast Thailand

    NARCIS (Netherlands)

    Cruz Garcia, G.S.; Price, L.L.

    2011-01-01

    Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as agricul

  12. A study of the early detection of insect infestations and density/distribution of host plants

    Science.gov (United States)

    Hart, W. G.; Ingle, S. J.; Davis, M. R. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Significant results have been obtained in the identification of citrus, sugarcane, winter vegetables, irrigated pastures, and unimproved pastures which contain brush. Land without vegetation, lakes, roads, and waterways can also be determined. Different densities of vegetation covering some cultivated areas are apparent. The practical applications of these results are many. The abundance of host plants of pests can be determined. Avenues of entry of pests can be plotted, facilitating control or preventing entry of pest species. The boundaries of areas to be quarantined can be accurately established after viewing the S-190B data. Better cultural methods can be employed such as planning where to plant certain crops that indirectly are detrimental to those already growing. This would relate to such factors as pesticide drift or alternate hosts of major pests.

  13. Enhanced drought tolerance of transgenic rice plants expressing a pea manganese superoxide dismutase.

    Science.gov (United States)

    Wang, Fang-Zheng; Wang, Qing-Bin; Kwon, Suk-Yoon; Kwak, Sang-Soo; Su, Wei-Ai

    2005-04-01

    We investigated the role that manganese superoxide dismutase (MnSOD), an important antioxidant enzyme, may play in the drought tolerance of rice. MnSOD from pea (Pisum sativum) under the control of an oxidative stress-inducible SWPA2 promoter was introduced into chloroplasts of rice (Oryza sativa) by Agrobacterium-mediated transformation to develop drought-tolerant rice plants. Functional expression of the pea MnSOD in transgenic rice plants (T1) was revealed under drought stress induced by polyethylene glycol (PEG) 6000. After PEG treatment the transgenic leaf slices showed reduced electrolyte leakage compared to wild type (WT) leaf slices, whether they were exposed to methyl viologen (MV) or not, suggesting that transgenic plants were more resistant to MV- or PEG-induced oxidative stress. Transgenic plants also exhibited less injury, measured by net photosynthetic rate, when treated with PEG. Our data suggest that SOD is a critical component of the ROS scavenging system in plant chloroplasts and that the expression of MnSOD can improve drought tolerance in rice.

  14. Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants.

    Science.gov (United States)

    Doni, Febri; Isahak, Anizan; Che Mohd Zain, Che Radziah; Wan Yusoff, Wan Mohtar

    2014-01-01

    Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO2 concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO2 m(-2) s(-1)), internal CO2 concentration (336.97 ppm), water use efficiency (1.15 μmoCO2/mmoH2O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation.

  15. Evaluating Leaf and Canopy Reflectance of Stressed Rice Plants to Monitor Arsenic Contamination.

    Science.gov (United States)

    Bandaru, Varaprasad; Daughtry, Craig S; Codling, Eton E; Hansen, David J; White-Hansen, Susan; Green, Carrie E

    2016-06-18

    Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor arsenic in rice plants. Four arsenic levels were induced in hydroponically grown rice plants with application of 0, 5, 10 and 20 µmol·L(-1) sodium arsenate. Reflectance spectra of upper fully expanded leaves were acquired over visible and infrared (NIR) wavelengths. Additionally, canopy reflectance for the four arsenic levels was simulated using SAIL (Scattering by Arbitrarily Inclined Leaves) model for various soil moisture conditions and leaf area indices (LAI). Further, sensitivity of various vegetative indices (VIs) to arsenic levels was assessed. Results suggest that plants accumulate high arsenic amounts causing plant stress and changes in reflectance characteristics. All leaf spectra based VIs related strongly with arsenic with coefficient of determination (r²) greater than 0.6 while at canopy scale, background reflectance and LAI confounded with spectral signals of arsenic affecting the VIs' performance. Among studied VIs, combined index, transformed chlorophyll absorption reflectance index (TCARI)/optimized soil adjusted vegetation index (OSAVI) exhibited higher sensitivity to arsenic levels and better resistance to soil backgrounds and LAI followed by red edge based VIs (modified chlorophyll absorption reflectance index (MCARI) and TCARI) suggesting that these VIs could prove to be valuable aids for monitoring arsenic in rice fields.

  16. Biotoxic efficacy of two horticultural plants against infestation of Sitophilus oryzae on stored maize

    Directory of Open Access Journals (Sweden)

    Mercy Olayinka ONI

    2016-06-01

    Full Text Available Since botanicals still remained the most promising tool that could obviate the use of chemical insecticides, this study investigated the biotoxic effect of Acacia auriculiformis and Acalypha goddsefiana powder and oil against Sitophilus oryzae. The powder of the plants were tested at 0.0g (control, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0g dosages while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations per 20g of maize seeds. Solvent control was also prepared for the oil extracts bioassay. Mortality, adult emergence, % inhibition rate and % weight loss were observed. LD50 and LC50 of the powders and oils of the two botanicals were calculated at 48 hours of application. The powders of both plants achieved complete weevil mortality within 72h of application at 2.0g and their effect was significantly (p<0.05 different from other dosages except 1.0g dosage. Also, the extracts of both plant achieved 100% insect mortality within 48h hours of application at 5%. However the powder and oil of A. auriculiformis appeared more effective than that of A. goddsefiana in term of mortality as reflected by their lethal dosage and concentration. However, A. goddsefiana powder and extract appeared more effective than that of A. auriculiformis in term of protectability as they greatly reduced the emergence of the adult weevil and their ability to cause weight loss of the maize grains. Only the higher dosages and concentrations of the plants were able to achieve 100% inhibition rate.

  17. Plant regeneration from mesophyll protoplast of indica rice Qiugui'ai 11 (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    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.

  18. A Web-Based Rice Plant Expert System Using Rule-Based Reasoning

    Directory of Open Access Journals (Sweden)

    Anton Setiawan Honggowibowo

    2009-12-01

    Full Text Available Rice plants can be attacked by various kinds of diseases which are possible to be determined from their symptoms. However, it is to recognize that to find out the exact type of disease, an agricultural expert’s opinion is needed, meanwhile the numbers of agricultural experts are limited and there are too many problems to be solved at the same time. This makes a system with a capability as an expert is required. This system must contain the knowledge of the diseases and symptom of rice plants as an agricultural expert has to have. This research designs a web-based expert system using rule-based reasoning. The rule are modified from the method of forward chaining inference and backward chaining in order to to help farmers in the rice plant disease diagnosis. The web-based rice plants disease diagnosis expert system has the advantages to access and use easily. With web-based features inside, it is expected that the farmer can accesse the expert system everywhere to overcome the problem to diagnose rice diseases.

  19. Sago-type palms were an important plant food prior to rice in southern subtropical China.

    Science.gov (United States)

    Yang, Xiaoyan; Barton, Huw J; Wan, Zhiwei; Li, Quan; Ma, Zhikun; Li, Mingqi; Zhang, Dan; Wei, Jun

    2013-01-01

    Poor preservation of plant macroremains in the acid soils of southern subtropical China has hampered understanding of prehistoric diets in the region and of the spread of domesticated rice southwards from the Yangtze River region. According to records in ancient books and archaeological discoveries from historical sites, it is presumed that roots and tubers were the staple plant foods in this region before rice agriculture was widely practiced. But no direct evidences provided to test the hypothesis. Here we present evidence from starch and phytolith analyses of samples obtained during systematic excavations at the site of Xincun on the southern coast of China, demonstrating that during 3,350-2,470 aBC humans exploited sago palms, bananas, freshwater roots and tubers, fern roots, acorns, Job's-tears as well as wild rice. A dominance of starches and phytoliths from palms suggest that the sago-type palms were an important plant food prior to the rice in south subtropical China. We also believe that because of their reliance on a wide range of starch-rich plant foods, the transition towards labour intensive rice agriculture was a slow process.

  20. Sago-type palms were an important plant food prior to rice in southern subtropical China.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Yang

    Full Text Available Poor preservation of plant macroremains in the acid soils of southern subtropical China has hampered understanding of prehistoric diets in the region and of the spread of domesticated rice southwards from the Yangtze River region. According to records in ancient books and archaeological discoveries from historical sites, it is presumed that roots and tubers were the staple plant foods in this region before rice agriculture was widely practiced. But no direct evidences provided to test the hypothesis. Here we present evidence from starch and phytolith analyses of samples obtained during systematic excavations at the site of Xincun on the southern coast of China, demonstrating that during 3,350-2,470 aBC humans exploited sago palms, bananas, freshwater roots and tubers, fern roots, acorns, Job's-tears as well as wild rice. A dominance of starches and phytoliths from palms suggest that the sago-type palms were an important plant food prior to the rice in south subtropical China. We also believe that because of their reliance on a wide range of starch-rich plant foods, the transition towards labour intensive rice agriculture was a slow process.

  1. Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Martin-Urdiroz, Magdalena; Oses-Ruiz, Miriam; Ryder, Lauren S; Talbot, Nicholas J

    2016-05-01

    The rice blast fungus, Magnaporthe oryzae, is responsible for the most serious disease of rice and is a continuing threat to ensuring global food security. The fungus has also, however, emerged as a model experimental organism for understanding plant infection processes by pathogenic fungi. This is largely due to its amenability to both classical and molecular genetics, coupled with the efforts of a very large international research community. This review, which is based on a plenary presentation at the 28th Fungal Genetics Conference in Asilomar, California in March 2015, describes recent progress in understanding how M. oryzae uses specialised cell called appressoria to bring about plant infection and the underlying biology of this developmental process. We also review how the fungus is then able to proliferate within rice tissue, deploying effector proteins to facilitate its spread by suppressing plant immunity and promoting growth and development of the fungus.

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

    Directory of Open Access Journals (Sweden)

    Sucheta SHARMA

    2014-11-01

    Full Text Available 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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. No-tillage effects on N and P exports across a rice-planted watershed.

    Science.gov (United States)

    Liang, Xinqiang; Wang, Zhibo; Zhang, Yixiang; Zhu, Chunyan; Lin, Limin; Xu, Lixian

    2016-05-01

    No tillage (NT) can be used as a management tool to alleviate the negative effects of agricultural practices on the environment by reducing the runoff volume and nutrient exports. The main objective of this research was to quantify the effect of NT on nitrogen (N) and phosphorus (P) exports across a rice-planted watershed using the soil and water assessment tool (SWAT) model. Results show that total N and P runoff exports from rice fields across the watershed ranged from 7.2 to 22.8 kg N/ha and 0.56 to 6.80 kg P/ha, respectively, over five rice-growing seasons under conventional tillage (CT) practice. The adoption of NT reduced the runoff volume, and the total N and total P exports by 25.9, 8.5, and 7.8 %, respectively, compared with the total exports under CT practice in the same study area. Rice yields were reduced by 0.7-1.9 % within the first 4 years after the adoption of NT, but began to rise in the fifth year. These results suggest that a long-term period of NT practice is necessary to reduce N and P exports without comprising the rice yield on rice-planted watersheds. In addition, the benefits of implementing NT practice alone were limited, and other practices, such as water and nutrient management, should be combined with NT practice.

  5. Plant root transcriptome profiling reveals a strain-dependent response during Azospirillum-rice cooperation

    Directory of Open Access Journals (Sweden)

    Benoît eDrogue

    2014-11-01

    Full Text Available Cooperation involving Plant Growth-Promoting Rhizobacteria results in improvements of plant growth and health. While pathogenic and symbiotic interactions are known to induce transcriptional changes for genes related to plant defence and development, little is known about the impact of phytostimulating rhizobacteria on plant gene expression. This study aims at identifying genes significantly regulated in rice roots upon Azospirillum inoculation, considering possible favored interaction between a strain and its original host cultivar. Genome-wide analyses of Oryza sativa japonica cultivars Cigalon and Nipponbare were performed, by using microarrays, seven days post inoculation with A. lipoferum 4B (isolated from Cigalon or Azospirillum sp. B510 (isolated from Nipponbare and compared to the respective non-inoculated condition. A total of 7,384 genes were significantly regulated, which represent about 16 % of total rice genes. A set of 34 genes is regulated by both Azospirillum strains in both cultivars, including a gene orthologous to PR10 of Brachypodium, and these could represent plant markers of Azospirillum-rice interactions. The results highlight a strain-dependent response of rice, with 83 % of the differentially expressed genes being classified as combination-specific. Whatever the combination, most of the differentially expressed genes are involved in primary metabolism, transport, regulation of transcription and protein fate. When considering genes involved in response to stress and plant defence, it appears that strain B510, a strain displaying endophytic properties, leads to the repression of a wider set of genes than strain 4B. Individual genotypic variations could be the most important driving force of rice roots gene expression upon Azospirillum inoculation. Strain-dependent transcriptional changes observed for genes related to auxin and ethylene signalling highlight the complexity of hormone signalling networks in the Azospirillum-rice

  6. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    OpenAIRE

    Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Delusional infestation.

    Science.gov (United States)

    Freudenmann, Roland W; Lepping, Peter

    2009-10-01

    This papers aims at familiarizing psychiatric and nonpsychiatric readers with delusional infestation (DI), also known as delusional parasitosis. It is characterized by the fixed belief of being infested with pathogens against all medical evidence. DI is no single disorder but can occur as a delusional disorder of the somatic type (primary DI) or secondary to numerous other conditions. A set of minimal diagnostic criteria and a classification are provided. Patients with DI pose a truly interdisciplinary problem to the medical system. They avoid psychiatrists and consult dermatologists, microbiologists, or general practitioners but often lose faith in professional medicine. Epidemiology and history suggest that the imaginary pathogens change constantly, while the delusional theme "infestation" is stable and ubiquitous. Patients with self-diagnosed "Morgellons disease" can be seen as a variation of this delusional theme. For clinicians, clinical pathways for efficient diagnostics and etiology-specific treatment are provided. Specialized outpatient clinics in dermatology with a liaison psychiatrist are theoretically best placed to provide care. The most intricate problem is to engage patients in psychiatric therapy. In primary DI, antipsychotics are the treatment of choice, according to limited but sufficient evidence. Pimozide is no longer the treatment of choice for reasons of drug safety. Future research should focus on pathophysiology and the neural basis of DI, as well as on conclusive clinical trials, which are widely lacking. Innovative approaches will be needed, since otherwise patients are unlikely to adhere to any study protocol.

  9. Paddy-field contamination with 134Cs and 137Cs due to Fukushima Dai-ichi Nuclear Power Plant accident and soil-to-rice transfer coefficients.

    Science.gov (United States)

    Endo, Satoru; Kajimoto, Tsuyoshi; Shizuma, Kiyoshi

    2013-02-01

    The transfer coefficient (TF) from soil to rice plants of (134)Cs and (137)Cs in the form of radioactive deposition from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 was investigated in three rice paddy fields in Minami-Soma City. Rice crops were planted in the following May and harvested at the end of September. Soil cores of 30-cm depth were sampled from rice-planted paddy fields to measure (134)Cs and (137)Cs radioactivity at 5-cm intervals. (134)Cs and (137)Cs radioactivity was also measured in rice ears (rice with chaff), straws and roots. The rice ears were subdivided into chaff, brown rice, polished rice and rice bran, and the (134)Cs and (137)Cs radioactivity concentration of each plant part was measured to calculate the respective TF from the soil. The TF of roots was highest at 0.48 ± 0.10 in the field where the (40)K concentration in the soil core was relatively low, in comparison with TF values of 0.31 and 0.38 in other fields. Similar trends could be found for the TF of whole rice plants, excluding roots. The TF of rice ears was relatively low at 0.019-0.026. The TF of chaff, rice bran, brown rice and polished rice was estimated to be 0.049, 0.10-0.16, 0.013-0.017 and 0.005-0.013, respectively.

  10. The enhanced drought tolerance of rice plants under ammonium is related to aquaporin (AQP).

    Science.gov (United States)

    Ding, Lei; Gao, Cuimin; Li, Yingrui; Li, Yong; Zhu, Yiyong; Xu, Guohua; Shen, Qirong; Kaldenhoff, Ralf; Kai, Lei; Guo, Shiwei

    2015-05-01

    Previously, we demonstrated that drought resistance in rice seedlings was increased by ammonium (NH4(+)) treatment, but not by nitrate (NO3(-)) treatment, and that the change was associated with root development. To study the effects of different forms of nitrogen on water uptake and root growth under drought conditions, we subjected two rice cultivars (cv. 'Shanyou 63' hybrid indica and cv. 'Yangdao 6' indica, China) to polyethylene glycol-induced drought stress in a glasshouse using hydroponic culture. Under drought conditions, NH4(+) significantly stimulated root growth compared to NO3(-), as indicated by the root length, surface area, volume, and numbers of lateral roots and root tips. Drought stress decreased the root elongation rate in both cultivars when they were supplied with NO3(-), while the rate was unaffected in the presence of NH4(+). Drought stress significantly increased root protoplast water permeability, root hydraulic conductivity, and the expression of root aquaporin (AQP) plasma intrinsic protein (PIP) genes in rice plants supplied with NH4(+); these changes were not observed in plants supplied with NO3(-). Additionally, ethylene, which is involved in the regulation of root growth, accumulated in rice roots supplied with NO3(-) under conditions of drought stress. We conclude that the increase in AQP expression and/or activity enhanced the root water uptake ability and the drought tolerance of rice plants supplied with NH4(+).

  11. Resistance to rice blast(Pyricularia oryzae) caused by the expression of trichosanthin gene in transgenic rice plants transferred through agrobacterium method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The gene of trichosanthin has been transferred into rice plants through agrobacterium method.The single copy insertion and the expression of foreign gene have been proved in regenerated plants.In antifungal assay the degrees of rice blast (Pyricularia oryzae) infection of the transgenic plants expressing trichosanthin and expressing GUS gene as control have been evaluated.The differences such as the time of disease symptom observed,the number of infected plants and damaged leaves,the growth of infected plants of the two transgenic plants after being inoculated by rice blast (Pyricularia oryzae) are significant.The transgenic plants with trichosanthin gene grew faster than the plants with GUS gene,even when humidity environment was removed.The results show that the transgenic plants that expressed trichosanthin are able to delay the infection of rice blast compared with the plants as control.In addition,no damage caused by the expression of trichosanthin gene in transgenic plants has been observed.

  12. Neem seed extract shampoo, Wash Away Louse, an effective plant agent against Sarcoptes scabiei mites infesting dogs in Egypt.

    Science.gov (United States)

    Abdel-Ghaffar, Fathy; Al-Quraishy, Saleh; Sobhy, Hassan; Semmler, Margit

    2008-12-01

    In the present study, the efficacy of water-free neem seed extract shampoo Wash Away Louse, provided by Alpha-Biocare GmbH, Düsseldorf (Germany), was investigated against Sarcoptes scabiei infesting dogs in Egypt. Ten naturally infested dogs were collected from different areas in the Nile delta. The occurrence of lesions, hair loss, and skin inflammation were regarded as signs of infestation and proved by detection of adult parasites and their developmental stages in scrapings of infested lesions. Adequate amount of the provided shampoo was applied topically and spread on the infested areas daily for 14 successive days. Scraping examinations were used to follow up the healing process. At day 7 of application, four dogs were completely free of mites as was proven by the disappearance of adults and/or any developmental stages of mites. The remaining six dogs showed a clear decrease in mite counts. By the end of the treatment (after 14 days), only a small number of mites were found in two dogs, while eight dogs were completely cured as was proven by mite counts and disappearance of clinical signs. No remarkable signs of side effects or adverse reactions were observed throughout the study.

  13. silencing COI1 in rice increases susceptibility to chewing insects and impairs inducible defense.

    Directory of Open Access Journals (Sweden)

    Mao Ye

    Full Text Available The jasmonic acid (JA pathway plays a key role in plant defense responses against herbivorous insects. CORONATINE INSENSITIVE1 (COI1 is an F-box protein essential for all jasmonate responses. However, the precise defense function of COI1 in monocotyledonous plants, especially in rice (Oryza sativa L. is largely unknown. We silenced OsCOI1 in rice plants via RNA interference (RNAi to determine the role of OsCOI1 in rice defense against rice leaf folder (LF Cnaphalocrocis medinalis, a chewing insect, and brown planthopper (BPH Nilaparvata lugens, a phloem-feeding insect. In wild-type rice plants (WT, the transcripts of OsCOI1 were strongly and continuously up-regulated by LF infestation and methyl jasmonate (MeJA treatment, but not by BPH infestation. The abundance of trypsin protease inhibitor (TrypPI, and the enzymatic activities of polyphenol oxidase (PPO and peroxidase (POD were enhanced in response to both LF and BPH infestation, but the activity of lipoxygenase (LOX was only induced by LF. The RNAi lines with repressed expression of OsCOI1 showed reduced resistance against LF, but no change against BPH. Silencing OsCOI1 did not alter LF-induced LOX activity and JA content, but it led to a reduction in the TrypPI content, POD and PPO activity by 62.3%, 48.5% and 27.2%, respectively. In addition, MeJA-induced TrypPI and POD activity were reduced by 57.2% and 48.2% in OsCOI1 RNAi plants. These results suggest that OsCOI1 is an indispensable signaling component, controlling JA-regulated defense against chewing insect (LF in rice plants, and COI1 is also required for induction of TrypPI, POD and PPO in rice defense response to LF infestation.

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

    Science.gov (United States)

    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.

  15. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Directory of Open Access Journals (Sweden)

    Jun-Fei Gu

    2013-12-01

    Full Text Available Maize-specific pyruvate orthophosphate dikinase (PPDK was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK. The wild-type (WT cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW, moderate drought (MD and severe drought (SD, were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities, biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines (PPDK and PCK were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by 45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%, 20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments, respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase (PEPC and carbonic anhydrase (CA in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4 photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to drought-tolerance breeding via overexpression of C4 enzymes in rice.

  16. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Institute of Scientific and Technical Information of China (English)

    Jun-Fei; Gu; Ming; Qiu; Jian-Chang; Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.

  17. Construction of plant expression vectors carrying glnA gene encoding glutamine synthetase and regeneration of transgenic rice plants

    Institute of Scientific and Technical Information of China (English)

    苏金; 张雪琴; 颜秋生; 陈章良; 尤崇杓

    1995-01-01

    The glnA gene encoding glutamine synthetase (GS) was amplified from Azospirillum brasilenseSp7 with PCR technique.The amplified 1.4-kb DNA fragment flanked with a BamH Ⅰ site at each end wascloned into EcoR V site of Bluescript-SK vector.A recombinant plasmid pGSJ1 containing this 1.4-kb DNA frag-ment was selected by restriction digestion analysis.The sequencing data also confirmed that the amplified 1.4-kbDNA fragment was undoubtedly the glnA gene of A.brasilense Sp7.Then the 1.4-kb BamH Ⅰ fragment was ex-cised from pGSJ1.A glnA plant expression vector pAGNB92 with rice actin 1 (Act1) promoter was constructedby using colony in situ hybridization to screen positive clones,and 3 rounds of ligation and transformation wereperformed.Protoplasts isolated from rice (Oryza sativa,L.Japonica) cell suspension line (cv.T986) weretransformed with the glnA plant expression vector pAGNB92 carrying neomycin phosphotransferase Ⅱ (NPT Ⅱ)gene by PEG fusion or electroporation.G418~ calli were used to detect NPT Ⅱ enzyme activity.The resultsshow that G418~ calli possess high positive hybridization signal with the frequency of 37%.The regeneratedG418~NPTII~+ rice plants were used for PCR amplification of glnA gene,and a 1.4-kb DNA fragment was ampli-fied from glnA-transgenic rice plants (R0 generation).The results of Southern blot hybridization prove that the1.4-kb DNA fragment amplified from the total DNA of glnA transgenic rice plants is indeed the glnA gene of A.brasilense Sp7.Northern blot hybridization was carried out using the same glnA gene as probe.The glnAgene was expressed in the transgenic rice plants.Bioassays also confirmed that the glnA transgenic rice plantsgrew much better than that of the control plants under a condition with nitrogen poor source (0.75 mmol/L).

  18. Delivery of roxarsone via chicken diet→chicken→chicken manure→soil→rice plant.

    Science.gov (United States)

    Yao, Lixian; Huang, Lianxi; He, Zhaohuan; Zhou, Changmin; Lu, Weisheng; Bai, Cuihua

    2016-10-01

    Roxarsone (ROX), a widely used feed additive, occurs as itself and its metabolites in animal manure. Rice is prone to accumulate As than other staple food. Four diets with 0, 40, 80 and 120mgROXkg(-1) were fed in chickens, and four chicken manures (CMs) were collected to fertilize rice plants in a soil culture experiment. Linear regression analysis shows that the slopes of As species including 4-hydroxy-phenylarsonic acid, As(V), As(III), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in CM versus dietary ROX were 0.033, 0.314, 0.033, 0.054 and 0.138, respectively. Both As(III) and DMA were determined in all rice grains, and As(III), As(V), MMA and DMA in rice hull, but detectable As forms in rice straws and soils increased with increasing ROX dose. Grain As(III) was unrelated to ROX dose but exceeded the Chinese rice As limit (0.15mgAs(III)kg(-1)). Dietary ROX enhanced straw As(III) mostly, with the slope of 0.020, followed by hull DMA (0.006) and grain DMA (0.002). The slopes of soil As(V) and As(III) were 0.003 and 0.001. This is the first report illustrating the quantitative delivery of ROX via food chain, which helps to evaluate health and environmental risks caused by ROX use in animal production.

  19. Sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related PRms protein in rice plants.

    Science.gov (United States)

    Gómez-Ariza, Jorge; Campo, Sonia; Rufat, Mar; Estopà, Montserrat; Messeguer, Joaquima; San Segundo, Blanca; Coca, María

    2007-07-01

    Expression of pathogenesis-related (PR) genes is part of the plant's natural defense response against pathogen attack. The PRms gene encodes a fungal-inducible PR protein from maize. Here, we demonstrate that expression of PRms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (Magnaporthe oryzae, Fusarium verticillioides, and Helminthosporium oryzae) and bacterial (Erwinia chrysanthemi) pathogens. The PRms-mediated disease resistance in rice plants is associated with an enhanced capacity to express and activate the natural plant defense mechanisms. Thus, PRms rice plants display a basal level of expression of endogenous defense genes in the absence of the pathogen. PRms plants also exhibit stronger and quicker defense responses during pathogen infection. We also have found that sucrose accumulates at higher levels in leaves of PRms plants. Sucrose responsiveness of rice defense genes correlates with the pathogen-responsive priming of their expression in PRms rice plants. Moreover, pretreatment of rice plants with sucrose enhances resistance to M. oryzae infection. Together, these results support a sucrose-mediated priming of defense responses in PRms rice plants which results in broad-spectrum disease resistance.

  20. Monitoring arsenic contamination in agricultural soils with reflectance spectroscopy of rice plants.

    Science.gov (United States)

    Shi, Tiezhu; Liu, Huizeng; Wang, Junjie; Chen, Yiyun; Fei, Teng; Wu, Guofeng

    2014-06-03

    The objective of this study was to explore the feasibility and to investigate the mechanism for rapidly monitoring arsenic (As) contamination in agricultural soils with the reflectance spectra of rice plants. Several data pretreatment methods were applied to improve the prediction accuracy. The prediction of soil As contents was achieved by partial least-squares regression (PLSR) using laboratory and field spectra of rice plants, as well as linear regression employing normalized difference spectral index (NDSI) calculated from fild spectra. For laboratory spectra, the optimal PLSR model for predicting soil As contents was achieved using Savitzky-Golay smoothing (SG), first derivative and mean center (MC) (root-mean-square error of prediction (RMSEP)=14.7 mg kg(-1); r=0.64; residual predictive deviation (RPD)=1.31). For field spectra, the optimal PLSR model was also achieved using SG, first derivative and MC (RMSEP=13.7 mg kg(-1); r=0.71; RPD=1.43). In addition, the NDSI with 812 and 782 nm obtained a prediction accuracy with r=0.68, RMSEP=13.7 mg kg(-1), and RPD=1.36. These results indicated that it was feasible to monitor the As contamination in agricultural soils using the reflectance spectra of rice plants. The prediction mechanism might be the relationship between the As contents in soils and the chlorophyll-a/-b contents and cell structure in leaves or canopies of rice plants.

  1. Rice GTPase OsRacB: Potential Accessory Factor in Plant Salt-stress Signaling

    Institute of Scientific and Technical Information of China (English)

    Min LUO; Su-Hai GU; Shu-Hui ZHAO; Fang ZHANG; Nai-Hu WU

    2006-01-01

    As the sole ubiquitous signal small guanosine triphosphate-binding protein in plants, Rop gene plays an important role in plant growth and development. In this study, we focus on the relationship between the novel rice Rop gene OsRacB and plant salt tolerance. Results show that OsRacB transcription is highly accumulated in roots after treatment with salinity, but only slightly accumulated in stems and leaves under the same treatment. Promoter analysis showed that OsRacB promoter is induced by salinity and exogenous salicylic acid, not abscisic acid. To elucidate its physiological function, we generated OsRacB sense and antisense transgenic tobacco and rice. Under proper salinity treatment, sense transgenic plants grew much better than the control. This suggests that overexpression of OsRacB in tobacco and rice can improve plant salt tolerance. But under the same treatment, no difference could be observed between OsRacB antisense plants and the control. The results indicated that OsRacB is only an accessory factor in plant salt tolerance.

  2. Molecular evidence for biochemical diversification of phenolamide biosynthesis in rice plants

    Institute of Scientific and Technical Information of China (English)

    Kimiaki Tanabe; Yuko Hojo; Tomonori Shinya; Ivan Galis

    2016-01-01

    Two phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine strongly accumulate in rice (Oryza sativa cv. Nipponbare) leaves subjected to attack of chewing and sucking herbivores. Here we identified and characterized in vitro three novel rice genes that mediated coumaroyl-CoA/feruloyl-CoA conjugation to polyamines, putrescine and agmatine. Interestingly, two genes were highly specific for their polyamine substrates, encoding putrescine N-hydrox-ycinnamoyltransferase and agmatine N-hydroxycinnamoyl-transferase, while the third enzyme could use both polyamines and it was therefore annotated as putrescine/agmatine N-hydroxycinnamoyltransferase. All genes were preferentially expressed in rice roots and developing flowers, and in addition, the putrescine/agmatine N-hydroxycinnamoyl-transferase transcripts were strongly induced by wounding in the young rice leaves. Because the wound response of this gene was only partially suppressed in the jasmonoyl-L-isoleucine deficient plants (Osjar1), it suggests that its upregulation (as well as inducible PAs in rice) may be largely independent of jasmonoyl-L-isoleucine signaling pathway. The finding of three closely related genes with a similar and/or overlapping activity in PA biosynthesis provides another striking example of rapid diversification of plant metabolism in response to environmental stresses in nature.

  3. Silicon reduces impact of plant nitrogen in promoting stalk borer (Eldana saccharina) but not sugarcane thrips (Fulmekiola serrata) infestations in sugarcane.

    Science.gov (United States)

    Keeping, Malcolm G; Miles, Neil; Sewpersad, Chandini

    2014-01-01

    The stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae) is a major limiting factor in South African sugarcane production, while yield is also reduced by sugarcane thrips Fulmekiola serrata Kobus (Thysanoptera: Thripidae). Borer management options include appropriate nitrogen (N) and enhanced silicon (Si) nutrition; the effect of N on sugarcane thrips is unknown. We tested the effects of these nutrients, in combination with resistant (N33) and susceptible (N27) sugarcane cultivars, on E. saccharina and F. serrata infestation. Two pot trials with three levels of N (60, 120, and 180 kg ha(-1)) and two levels each of calcium silicate and dolomitic lime (5 and 10 t ha(-1)) were naturally infested with thrips, then artificially water stressed and infested with borer. Higher N levels increased borer survival and stalk damage, while Si reduced these compared with controls. Silicon significantly reduced stalk damage in N27 but not in N33; hence, Si provided relatively greater protection for susceptible cultivars than for resistant ones. High N treatments were associated with greater thrips numbers, while Si treatments did not significantly influence thrips infestation. The reduction in borer survival and stalk damage by Si application at all N rates indicates that under field conditions, the opportunity exists for optimizing sugarcane yields through maintaining adequate N nutrition, while reducing populations of E. saccharina using integrated pest management (IPM) tactics that include improved Si nutrition of the crop and reduced plant water stress. Improved management of N nutrition may also provide an option for thrips IPM. The contrasting effects of Si on stalk borer and thrips indicate that Si-mediated resistance to insect herbivores in sugarcane has mechanical and biochemical components that are well developed in the stalk tissues targeted by E. saccharina but poorly developed in the young leaf spindles where F. serrata occurs.

  4. Silicon reduces impact of plant nitrogen in promoting stalk borer (Eldana saccharina but not sugarcane thrips (Fulmekiola serrata infestations in sugarcane

    Directory of Open Access Journals (Sweden)

    Malcolm Geoffrey Keeping

    2014-06-01

    Full Text Available The stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae is a major limiting factor in South African sugarcane production, while yield is also reduced by sugarcane thrips Fulmekiola serrata Kobus (Thysanoptera: Thripidae. Borer management options include appropriate nitrogen (N and enhanced silicon (Si nutrition; the effect of N on sugarcane thrips is unknown. We tested the effects of these nutrients, in combination with resistant (N33 and susceptible (N27 sugarcane cultivars, on E. saccharina and F. serrata infestation. Two pot trials with three levels of N (60, 120 and 180 kg ha-1 and two levels each of calcium silicate and dolomitic lime (5 t ha-1, 10 t ha-1 were naturally infested with thrips, then artificially water stressed and infested with borer. Higher N levels increased borer survival and stalk damage, while Si reduced these compared with controls. Silicon significantly reduced stalk damage in N27 but not in N33; hence, Si provided relatively greater protection for susceptible cultivars than for resistant ones. High N treatments were associated with greater thrips numbers, while Si treatments did not significantly influence thrips infestation. The reduction in borer survival and stalk damage by Si application at all N rates indicates that under field conditions, the opportunity exists for optimising sugarcane yields through maintaining adequate N nutrition, while reducing populations of E. saccharina using integrated pest management (IPM tactics that include improved Si nutrition of the crop and reduced plant water stress. Improved management of N nutrition may also provide an option for thrips IPM. The contrasting effects of Si on stalk borer and thrips indicate that Si-mediated resistance to insect herbivores in sugarcane has mechanical and biochemical components that are well developed in the stalk tissues targeted by E. saccharina but poorly developed in the young leaf spindles where F. serrata occurs.

  5. Expression of betaine aldehyde dehydrogenase gene and salinity tolerance in rice transgenic plants

    Institute of Scientific and Technical Information of China (English)

    郭岩; 张莉; 肖岗; 曹守云; 谷冬梅; 田文忠; 陈受宜

    1997-01-01

    Betaine as one of osmolytes plays an important role in osmoregulation of most high plants. Betaine aldehyde dehydrogenase C BADH) is the second enzyme involved in betaine biosynthesis. The BADH gene from a halophite, Atriplex hortensis, was transformed into rice cultivars by bombarment method. Totally 192 transgenic rice plants were obtained and most of them had higher salt tolerance than controls. Among transgenic plants transplanted in the saline pool containing 0.5% NaCl in a greenhouse, 22 survived, 13 of which set seeds, and the frequency of seed setting was very low, only 10% . But the controls could not grow under the same condition. The results of BADH ac-tivity assay and Northern blot showed that the BADH gene was integrated into chromosomes of transgenic plants and expressed.

  6. Effects of Plant Density and Nitrogen Application Rate on Grain Yield and Nitrogen Uptake of Super Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    LIN Xian-qing; ZHU De-feng; CHEN Hui-zhe; ZHANG Yu-ping

    2009-01-01

    The nitrogen uptake, yield and its components for two super-high-yielding hybrid rice combinations, Guodao 6 and Eryou 7954 were investigated under different plant densities (15, 18, and 21 plants/m2) and different nitrogen application rates (120, 150, 180, and 210 kg/hm2). The experiment was conducted on loam soil during 2004-2006 at the experimental farm of the China National Rice Research Institute in Hangzhou, China. In these years, the two hybrid rice clearly showed higher yield at a plant density of 15 plants/m2 with a nitrogen application rate of 180 kg/hm2. Guodao 6 produced an average grain yield of 10 215.6 kg/hm2 across the three years, while the yield of Eryou 7954 was 9 633.0 kg/hm2. With fewer plants per unit-area and larger plants in the plots, the two hybrid rice produced more panicles per plant in three years. The highest nitrogen uptake of the two hybrid rice was at a plant density of 15 plants/m2 with a nitrogen application rate of 180 kg/hm2. Further increasing nitrogen application rate was not advantageous for nitrogen uptake in super-high-yielding rice under the same plant density.

  7. Infestation by Coffee White Stem Borer, Xylotrechus quadripes, in Relation to Soil and Plant Nutrient Content and Associated Quality Aspects

    NARCIS (Netherlands)

    Thapa, Sushil; Lantinga, Egbert A.

    2016-01-01

    Infestation by coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) is becoming severe in parts of Asia and Africa. In recent years, the pest has also been found in North and South America. This study in Gulmi District, Nepal, aimed to determine the severity of infe

  8. Esterase as molecular marker for salt tolerance in regenerated plants of rice, Oryza sativa L.

    Science.gov (United States)

    Swapna, T S

    2002-09-01

    Esterase variation was studied in plants regenerated from callus cultures of four rice (Oryza sativa) varieties, viz. pokkali, which is a moderately salt tolerant variety and three salt sensitive varieties MI 48, annapoorna and jyothi. Variation was studied at tillering stage of plants regenerated from callus culture and germinated from seeds. Somaclonal variants for salt tolerance could be detected using variation in esterase banding pattern and activity.

  9. Role of silicon in alleviation of iron deficiency and toxicity in hydroponically-grown rice (Oryza sativa L.) plants

    OpenAIRE

    A Abdol Zadeh; z Kiani Chalmardi

    2013-01-01

    Silicon (Si) nutrition may alleviate biotic and abiotic stresses including heavy metal deficiency and toxicity in plants. Iron deficiency and toxicity are important limiting factors in growth of rice. In the present study, role of Si nutrition on alleviation of iron deficiency and toxicity was investigated in rice plants. Plants were cultivated in greenhouse in hydroponics, using Yoshida solution, under different iron treatments (0, 2, 10, 20, 50, 100 and 250 mg/L as Fe- EDTA) and Si nutritio...

  10. Plant/microbe cooperation for electricity generation in a rice paddy field.

    Science.gov (United States)

    Kaku, Nobuo; Yonezawa, Natsuki; Kodama, Yumiko; Watanabe, Kazuya

    2008-05-01

    Soils are rich in organics, particularly those that support growth of plants. These organics are possible sources of sustainable energy, and a microbial fuel cell (MFC) system can potentially be used for this purpose. Here, we report the application of an MFC system to electricity generation in a rice paddy field. In our system, graphite felt electrodes were used; an anode was set in the rice rhizosphere, and a cathode was in the flooded water above the rhizosphere. It was observed that electricity generation (as high as 6 mW/m(2), normalized to the anode projection area) was sunlight dependent and exhibited circadian oscillation. Artificial shading of rice plants in the daytime inhibited the electricity generation. In the rhizosphere, rice roots penetrated the anode graphite felt where specific bacterial populations occurred. Supplementation to the anode region with acetate (one of the major root-exhausted organic compounds) enhanced the electricity generation in the dark. These results suggest that the paddy-field electricity-generation system was an ecological solar cell in which the plant photosynthesis was coupled to the microbial conversion of organics to electricity.

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

    Science.gov (United States)

    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.

  12. Genetic evidence for natural product mediated plant–plant allelopathy in rice

    Science.gov (United States)

    Xu, Meimei; Galhano, Rita; Wiemann, Philipp; Bueno, Emilio; Tiernan, Mollie; Wu, William; Chung, Ill-Min; Gershenzon, Jonathan; Tudzynski, Bettina; Sesma, Ane; Peters, Reuben J.

    2011-01-01

    Summary A role for specific natural products in directly mediating antagonistic plant–plant interactions –that is, allelopathy –has been controversial. If proven, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (Oryza sativa).However, while substantiated by the presence of phytotoxic compounds at potentially relevant levels, demonstrating a direct role for specific natural products in allelopathy has been difficult due to the chemical complexity of root and plant litter exudates. This complexity can be bypassed via selective genetic manipulation to ablate production of putative allelopathic compounds, but such an approach previously has not been applied.The rice diterpenoid momilactones provide an example of natural products for which correlative biochemical evidence has been obtained for a role in allelopathy. Here, we apply reverse genetics, using knock-outs of the relevant diterpene synthases (OsCPS4 and OsKSL4), to demonstrate that rice momilactones are involved in allelopathy, including suppressing growth of the widespread rice paddy weed, barnyard grass (Echinochloa crus-galli).Thus, our results not only provide novel genetic evidence for natural product mediated allelopathy, but also furnish a molecular target for breeding and metabolic engineering of this important crop plant. PMID:22150231

  13. ACC deaminase and IAA producing growth promoting bacteria from the rhizosphere soil of tropical rice plants.

    Science.gov (United States)

    Bal, Himadri Bhusan; Das, Subhasis; Dangar, Tushar K; Adhya, Tapan K

    2013-12-01

    Beneficial plant-associated bacteria play a key role in supporting and/or promoting plant growth and health. Plant growth promoting bacteria present in the rhizosphere of crop plants can directly affect plant metabolism or modulate phytohormone production or degradation. We isolated 355 bacteria from the rhizosphere of rice plants grown in the farmers' fields in the coastal rice field soil from five different locations of the Ganjam district of Odisha, India. Six bacteria producing both ACC deaminase (ranging from 603.94 to 1350.02 nmol α-ketobutyrate mg(-1)  h(-1) ) and indole acetic acid (IAA; ranging from 10.54 to 37.65 μM ml(-1) ) in pure cultures were further identified using polyphasic taxonomy including BIOLOG((R)) , FAME analysis and the 16S rRNA gene sequencing. Phylogenetic analyses of the isolates resulted into five major clusters to include members of the genera Bacillus, Microbacterium, Methylophaga, Agromyces, and Paenibacillus. Seed inoculation of rice (cv. Naveen) by the six individual PGPR isolates had a considerable impact on different growth parameters including root elongation that was positively correlated with ACC deaminase activity and IAA production. The cultures also had other plant growth attributes including ammonia production and at least two isolates produced siderophores. Study indicates that presence of diverse rhizobacteria with effective growth-promoting traits, in the rice rhizosphere, may be exploited for a sustainable crop management under field conditions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effect of alternation of agar and agarose on the green plant differentiation frequency of calli from wild rice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ In vitro culture of wild rice was difficult. Recently, we found that high agarose concentration of different media could improve the green plant differentiation frequency of calli from wild rice. We tested the effectiveness of alternation of agar and agarose in different media.

  15. Regeneration of transgenic rice plants from protoplasts following plasmid uptake

    Institute of Scientific and Technical Information of China (English)

    LiWenbin; SUNYongru

    1994-01-01

    Embryogenic cell suspension was obtained from the calli developed from mature seeds of riceRoncarolo (Oryza sativa L., a japonica cultivar from Italy ). The protoplasts were isolated from cell suspension by treatment of enzyme mixture and suspended in the solution containing 0.56%(w/v) MgCl2· 6H2O,0.10%(w/v) MES and 0.4 mol/L, pH 5.6 mannitol to a final density of 2×105/ml.

  16. Studies on Plant Population and Stand Establishment Techniques for Increasing Productivity of Rice in Dera Ismail Khan, Pakistan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rice production in Pakistan is constraint by many factors pertaining to prevalent planting techniques. A research on the feasibility of new planting techniques (direct seeding on flat, transplanting on flat, direct seeding on ridges, transplanting on ridges and parachute planting) in transplanted and direct wet-seeded rice was undertaken at Dera Ismail Khan region of Pakistan's North West Frontier Province during 2002 and 2003. Among the planting techniques, the best performance for the yield formation and economic evaluation was noted for transplanting on flat during both years. Chinese parachute planting technology also showed very promising results in most of the parameters. Direct seeding on ridges could not excel transplanting on flat and parachute planting during both cropping seasons. The findings concluded the feasibility of parachute planting technology along with traditional rice transplanting on flat over all other planting techniques being practiced in the area.

  17. Studies on Plant Population and Stand Establishment Techniques for Increasing Productivity of Rice in Dera Ismail Khan, Pakistan

    Directory of Open Access Journals (Sweden)

    Mohammad Safdar BALOCH

    2007-06-01

    Full Text Available Rice production in Pakistan is constraint by many factors pertaining to prevalent planting techniques. A research on the feasibility of new planting techniques (direct seeding on flat, transplanting on flat, direct seeding on ridges, transplanting on ridges and parachute planting in transplanted and direct wet-seeded rice was undertaken at Dera Ismail Khan region of Pakistan's North West Frontier Province during 2002 and 2003. Among the planting techniques, the best performance for the yield formation and economic evaluation was noted for transplanting on flat during both years. Chinese parachute planting technology also showed very promising results in most of the parameters. Direct seeding on ridges could not excel transplanting on flat and parachute planting during both cropping seasons. The findings concluded the feasibility of parachute planting technology along with traditional rice transplanting on flat over all other planting techniques being practiced in the area.

  18. Assessment of water sources to plant growth in rice based cropping systems by stable water isotopes

    Science.gov (United States)

    Mahindawansha, Amani; Kraft, Philipp; Racela, Heathcliff; Breuer, Lutz

    2016-04-01

    Rice is one of the most water-consuming crops in the world. Understanding water source utilization of rice will help us to improve water use efficiency (WUE) in paddy management. The objectives of our study are to evaluate the isotopic compositions of surface ponded water, soil water, irrigation water, groundwater, rain water and plant water and based on stable water isotope signatures to evaluate the contributions of various water sources to plant growth (wet rice, aerobic rice and maize) together with investigating the contribution of water from different soil horizons for plant growth in different maturity periods during wet and dry seasons. Finally we will compare the water balances and crop yields in both crops during both seasons and calculate the water use efficiencies. This will help to identify the most efficient water management systems in rice based cropping ecosystems using stable water isotopes. Soil samples are collected from 9 different depths at up to 60 cm in vegetative, reproductive and matured periods of plant growth together with stem samples. Soil and plant samples are extracted by cryogenic vacuum extraction. Root samples are collected up to 60 cm depth from 10 cm intercepts leading calculation of root length density and dry weight. Groundwater, surface water, rain water and irrigation water are sampled weekly. All water samples are analyzed for hydrogen and oxygen isotope ratios (d18O and dD) using Los Gatos Research DLT100. Rainfall records, ground water level, surface water level fluctuations and the amount of water irrigated in each field will be measured during the sampling period. The direct inference approach which is based on comparing isotopic compositions (dD and d18O) between plant stem water and soil water will be used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These

  19. Modeling grain protein formation in relation to nitrogen uptake and remobilization in rice plant

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan; LI Weiguo; JING Qi; CAO Weixing; Takeshi Horie

    2007-01-01

    Protein concentration of grain is an important quality index of rice,and formation of grain protein largely depends on pre-anthesis nitrogen assimilation and postanthesis nitrogen remobilization in the rice plant.The primary objective of this study was to develop a simplified process model for simulating nitrogen accumulation and remobilization in plant and protein formation in rice grains on the basis of an established rice growth model.Six field experiments,involving different years,eco-sites,varieties,nitrogen rates,and irrigation regimes,were conducted to obtain the necessary data for model building,genotypic parameter determination,and model validation.Using physiological development time(PDT)as general time scale of development progress and cultivar-specific grain protein concentration as genotypic parameter,the dynamic relationships of plant nitrogen accumulation and translocation to environmental and genetic factors were quantified and synthesized in the present model.The pre-anthesis nitrogen uptake rate by plant changed with the PDT in a negative exponential pattern,and post-anthesis nitrogen uptake rate changed with leaf area index(LA1)in an exponential equation.Post-antbesis nitrogen translocation rate depended on the plant nitrogen concentration and dry weight at anthesis as well as residue nitrogen concentration of plant at maturity.The nitrogen for protein synthesis in grains came from two sources:the nitrogen pre-stored in leaves,stem and sheath before anthesis and then remobilized after anthesis,and the nitrogen absorbed directly by plant after anthesis.Finally,the model was tested by using the data sets of different years,eco-sites,varieties,and N fertilization and irrigation conditions with the root mean square errors(RMSE)0.22%-0.26%,indicating the general and reliable features of the model.It is hoped that by properly integrating with the existing rice growth models,the present model can be used for predicting grain protein concentration and

  20. Determination of degree of infestation of triticale seed using NIR spectroscopy

    Science.gov (United States)

    Insect infestation of seeds of the triticale hybrid, Triticosecale, causes extraordinary storage losses as a consequence of vulnerability of triticale seed to insect infestation and its soft coat. Rice weevil, Sitophilus oryzae (L.), is a common insect that causes infestation in Florida, which was t...

  1. Plant Growth Promotion and Suppression of Bacterial Leaf Blight in Rice by Inoculated Bacteria.

    Science.gov (United States)

    Yasmin, Sumera; Zaka, Abha; Imran, Asma; Zahid, Muhammad Awais; Yousaf, Sumaira; Rasul, Ghulam; Arif, Muhammad; Mirza, Muhammad Sajjad

    2016-01-01

    The present study was conducted to evaluate the potential of rice rhizosphere associated antagonistic bacteria for growth promotion and disease suppression of bacterial leaf blight (BLB). A total of 811 rhizospheric bacteria were isolated and screened against 3 prevalent strains of BLB pathogen Xanthomonas oryzae pv. oryzae (Xoo) of which five antagonistic bacteria, i.e., Pseudomonas spp. E227, E233, Rh323, Serratia sp. Rh269 and Bacillus sp. Rh219 showed antagonistic potential (zone of inhibition 1-19 mm). Production of siderophores was found to be the common biocontrol determinant and all the strains solubilized inorganic phosphate (82-116 μg mL-1) and produced indole acetic acid (0.48-1.85 mg L-1) in vitro. All antagonistic bacteria were non-pathogenic to rice, and their co-inoculation significantly improved plant health in terms of reduced diseased leaf area (80%), improved shoot length (31%), root length (41%) and plant dry weight (60%) as compared to infected control plants. Furthermore, under pathogen pressure, bacterial inoculation resulted in increased activity of defense related enzymes including phenylalanine ammonia-lyase and polyphenol oxidase, along with 86% increase in peroxidase and 53% increase in catalase enzyme activities in plants inoculated with Pseudomonas sp. Rh323 as well as co-inoculated plants. Bacterial strains showed good colonization potential in the rice rhizosphere up to 21 days after seed inoculation. Application of bacterial consortia in the field resulted in an increase of 31% in grain yield and 10% in straw yield over non-inoculated plots. Although, yield increase was statistically non-significant but was accomplished with overall saving of 20% chemical fertilizers. The study showed that Pseudomonas sp. Rh323 can be used to develop dual-purpose inoculum which can serve not only to suppress BLB but also to promote plant growth in rice.

  2. Ethnobotanical investigation of 'wild' food plants used by rice farmers in Kalasin, Northeast Thailand

    Directory of Open Access Journals (Sweden)

    Cruz-Garcia Gisella S

    2011-11-01

    Full Text Available Abstract Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as agricultural areas rather than pristine ecosystems. This paper provides selected results from a study of wild food conducted in several villages in Northeast Thailand. A complete botanical inventory of wild food plants from these communities and surrounding areas is provided including their diversity of growth forms, the different anthropogenic locations were these species grow and the multiplicity of uses they have. Methods Data was collected using focus groups and key informant interviews with women locally recognized as knowledgeable about contemporarily gathered plants. Plant species were identified by local taxonomists. Results A total of 87 wild food plants, belonging to 47 families were reported, mainly trees, herbs (terrestrial and aquatic and climbers. Rice fields constitute the most important growth location where 70% of the plants are found, followed by secondary woody areas and home gardens. The majority of species (80% can be found in multiple growth locations, which is partly explained by villagers moving selected species from one place to another and engaging in different degrees of management. Wild food plants have multiple edible parts varying from reproductive structures to vegetative organs. More than two thirds of species are reported as having diverse additional uses and more than half of them are also regarded as medicine. Conclusions This study shows the remarkable importance of anthropogenic areas in providing wild food plants. This is reflected in the great diversity of species found, contributing to the food and nutritional security of rice farmers in Northeast Thailand.

  3. Overexpression of Nictaba-Like Lectin Genes from Glycine max Confers Tolerance towards Pseudomonas syringae Infection, Aphid Infestation and Salt Stress in Transgenic Arabidopsis Plants

    Directory of Open Access Journals (Sweden)

    Sofie Van Holle

    2016-10-01

    Full Text Available Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL groups all proteins with homology to the tobacco (Nicotiana tabacum lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max, referred to as GmNLL1 and GmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed in Nicotiana benthamiana leaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for the GmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment, Phytophthora sojae infection and Aphis glycines infestation trigger the expression of particular NLL genes. Stress experiments with Arabidopsis lines overexpressing the NLLs from soybean yielded an enhanced tolerance of the plant towards bacterial infection (Pseudomonas syringae, insect infestation (Myzus persicae and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions.

  4. Overexpression of Nictaba-Like Lectin Genes from Glycine max Confers Tolerance toward Pseudomonas syringae Infection, Aphid Infestation and Salt Stress in Transgenic Arabidopsis Plants

    Science.gov (United States)

    Van Holle, Sofie; Smagghe, Guy; Van Damme, Els J. M.

    2016-01-01

    Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL) groups all proteins with homology to the tobacco (Nicotiana tabacum) lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max), referred to as GmNLL1 and GmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed in Nicotiana benthamiana leaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for the GmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment, Phytophthora sojae infection and Aphis glycines infestation trigger the expression of particular NLL genes. Stress experiments with Arabidopsis lines overexpressing the NLLs from soybean yielded an enhanced tolerance of the plant toward bacterial infection (Pseudomonas syringae), insect infestation (Myzus persicae) and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions. PMID:27826309

  5. Eliminating aluminum toxicity in an acid sulfate soil for rice cultivation using plant growth promoting bacteria.

    Science.gov (United States)

    Panhwar, Qurban Ali; Naher, Umme Aminun; Radziah, Othman; Shamshuddin, Jusop; Razi, Ismail Mohd

    2015-02-20

    Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB), ground magnesium limestone (GML) and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0) at various Al concentrations (0, 50 and 100 μM). Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB), GML and basalt were applied (4 t·ha-1 each). Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase.

  6. Eliminating Aluminum Toxicity in an Acid Sulfate Soil for Rice Cultivation Using Plant Growth Promoting Bacteria

    Directory of Open Access Journals (Sweden)

    Qurban Ali Panhwar

    2015-02-01

    Full Text Available Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB, ground magnesium limestone (GML and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0 at various Al concentrations (0, 50 and 100 μM. Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB, GML and basalt were applied (4 t·ha−1 each. Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase.

  7. Geochemical patterns and microbial contribution to iron plaque formation in the rice plant rhizosphere

    Science.gov (United States)

    Maisch, Markus; Murata, Chihiro; Unger, Julia; Kappler, Andreas; Schmidt, Caroline

    2015-04-01

    Rice is the major food source for more than half of the world population and 80 percent of the worldwide rice cultivation is performed on water logged paddy soils. The establishment of reducing conditions in the soil and across the soil-water interface not only stimulates the microbial production and release of the greenhouse gas methane. These settings also create optimal conditions for microbial iron(III) reduction and therefore saturate the system with reduced ferrous iron. Through the reduction and dissolution of ferric minerals that are characterized by their high surface activity, sorbed nutrients and contaminants (e.g. arsenic) will be mobilized and are thus available for uptake by plants. Rice plants have evolved a strategy to release oxygen from their roots in order to prevent iron toxification in highly ferrous environments. The release of oxygen to the reduced paddy soil causes ferric iron plaque formation on the rice roots and finally increases the sorption capacity for toxic metals. To this date the geochemical and microbiological processes that control the formation of iron plaque are not deciphered. It has been hypothesized that iron(II)-oxidizing bacteria play a potential role in the iron(III) mineral formation along the roots. However, not much is known about the actual processes, mineral products, and geochemical gradients that establish within the rhizosphere. In the present study we have developed a growth set-up that allows the co-cultivation of rice plants and iron(II)-oxidizing bacteria, as well as the visual observation and in situ measurement of geochemical parameters. Oxygen and dissolved iron(II) gradients have been measured using microelectrodes and show geochemical hot spots that offer optimal growth conditions for microaerophilic iron(II) oxidizers. First mineral identification attempts of iron plaque have been performed using Mössbauer spectroscopy and microscopy. The obtained results on mineraology and crystallinity have been

  8. Bridging Decision Tree Data Mining Model to the Automated Knowledge Base for Rice Plant Agriculture Expert System

    National Research Council Canada - National Science Library

    Divya Joy; Sreekumar K

    2015-01-01

    .... This paper presents a new methodology for the expert system design and uses a novel approach for the development with some data mining technique and implements a rule based expert system for rice plant...

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

    Science.gov (United States)

    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. Knocking down mitochondrial iron transporter (MIT) reprograms primary and secondary metabolism in rice plants.

    Science.gov (United States)

    Vigani, Gianpiero; Bashir, Khurram; Ishimaru, Yasuhiro; Lehmann, Martin; Casiraghi, Fabio Marco; Nakanishi, Hiromi; Seki, Motoaki; Geigenberger, Peter; Zocchi, Graziano; Nishizawa, Naoko K

    2016-03-01

    Iron (Fe) is an essential micronutrient for plant growth and development, and its reduced bioavailability strongly impairs mitochondrial functionality. In this work, the metabolic adjustment in the rice (Oryza sativa) mitochondrial Fe transporter knockdown mutant (mit-2) was analysed. Biochemical characterization of purified mitochondria from rice roots showed alteration in the respiratory chain of mit-2 compared with wild-type (WT) plants. In particular, proteins belonging to the type II alternative NAD(P)H dehydrogenases accumulated strongly in mit-2 plants, indicating that alternative pathways were activated to keep the respiratory chain working. Additionally, large-scale changes in the transcriptome and metabolome were observed in mit-2 rice plants. In particular, a strong alteration (up-/down-regulation) in the expression of genes encoding enzymes of both primary and secondary metabolism was found in mutant plants. This was reflected by changes in the metabolic profiles in both roots and shoots of mit-2 plants. Significant alterations in the levels of amino acids belonging to the aspartic acid-related pathways (aspartic acid, lysine, and threonine in roots, and aspartic acid and ornithine in shoots) were found that are strictly connected to the Krebs cycle. Furthermore, some metabolites (e.g. pyruvic acid, fumaric acid, ornithine, and oligosaccharides of the raffinose family) accumulated only in the shoot of mit-2 plants, indicating possible hypoxic responses. These findings suggest that the induction of local Fe deficiency in the mitochondrial compartment of mit-2 plants differentially affects the transcript as well as the metabolic profiles in root and shoot tissues. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. Dynamics of seed-borne rice endophytes on early plant growth stages.

    Directory of Open Access Journals (Sweden)

    Pablo R Hardoim

    Full Text Available Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed.

  12. Rice proteomics: A move toward expanded proteome coverage to comparative and functional proteomics uncovers the mysteries of rice and plant biology.

    Science.gov (United States)

    Agrawal, Ganesh Kumar; Rakwal, Randeep

    2011-05-01

    Growing rice is an important socio-economic activity. Rice proteomics has achieved a tremendous progress in establishing techniques to proteomes of almost all tissues, organs, and organelles during the past one decade (year 2000-2010). We have compiled these progresses time to time over this period. The present compilation discusses proteomics research in rice published between 1st April 2008 and 30th July 2010. Progress continues mainly towards protein cataloging deep into the proteome with high-confident protein assignment and some functional significance than ever before by (i) identifying previously unreported/low-abundance proteins, (ii) quantifying relative/absolute values of proteins, (iii) assigning protein responses to biotic/abiotic stresses, (iv) protein localization into organelles, (v) validating previous proteomes and eliminating false-positive proteins, and (vi) discovering potential biomarkers for tissues, organs, organelles, and for screening transgenic plants and food-safety evaluation. The notable achievements in global mapping of phosphorylation sites and identifying several novel secreted proteins into the extracellular space are worth appreciating. Our ever-increasing knowledge on the rice proteomics is beginning to impact the biology of not only rice, but also crops and plants. These major achievements will be discussed in this review keeping in mind newcomers, young, and established scientists in proteomics and plants. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Good manufacturing practices production of a purification-free oral cholera vaccine expressed in transgenic rice plants.

    Science.gov (United States)

    Kashima, Koji; Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Suzuki, Yuji; Minakawa, Satomi; Takeyama, Natsumi; Fukuyama, Yoshiko; Azegami, Tatsuhiko; Tanimoto, Takeshi; Kuroda, Masaharu; Tamura, Minoru; Gomi, Yasuyuki; Kiyono, Hiroshi

    2016-03-01

    The first Good Manufacturing Practices production of a purification-free rice-based oral cholera vaccine (MucoRice-CTB) from transgenic plants in a closed cultivation system yielded a product meeting regulatory requirements. Despite our knowledge of their advantages, plant-based vaccines remain unavailable for human use in both developing and industrialized countries. A leading, practical obstacle to their widespread use is producing plant-based vaccines that meet governmental regulatory requirements. Here, we report the first production according to current Good Manufacturing Practices of a rice-based vaccine, the cholera vaccine MucoRice-CTB, at an academic institution. To this end, we established specifications and methods for the master seed bank (MSB) of MucoRice-CTB, which was previously generated as a selection-marker-free line, evaluated its propagation, and given that the stored seeds must be renewed periodically. The production of MucoRice-CTB incorporated a closed hydroponic system for cultivating the transgenic plants, to minimize variations in expression and quality during vaccine manufacture. This type of molecular farming factory can be operated year-round, generating three harvests annually, and is cost- and production-effective. Rice was polished to a ratio of 95 % and then powdered to produce the MucoRice-CTB drug substance, and the identity, potency, and safety of the MucoRice-CTB product met pre-established release requirements. The formulation of MucoRice-CTB made by fine-powdering of drug substance and packaged in an aluminum pouch is being evaluated in a physician-initiated phase I study.

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

    Science.gov (United States)

    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.

  15. Impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the central plains.

    Science.gov (United States)

    Charlet, Laurence D; Aiken, Robert M; Meyer, Ron F; Gebre-Amlak, Assefa

    2007-08-01

    The guild of stem-infesting insect pests of sunflower, Helianthus annuus L., within the central Plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), and Dectes texanus texanus LeConte (Coleoptera: Cerambycidae). The incidence of a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), also has increased. Experiments were conducted in three locations in Colorado and Kansas during 2001-2003 to investigate the potential of combining planting date and foliar and seed treatment insecticide applications to lower insect stalk densities of these three pests. The impact of these strategies on weevil larval parasitoids also was studied. Eight sunflower stem weevil larval parasitoid species were identified. All were Hymenoptera and included the following (relative composition in parentheses): Nealiolus curculionis (Fitch) (42.6%), Nealiolus collaris (Brues) (3.2%) (Braconidae), Quadrastichus ainsliei Gahan (4.2%) (Eulophidae), Eurytoma tylodermatis Ashmead (13.1%) (Eurytomidae), Neocatolaccus tylodermae (Ashmead) (33.7%), Chlorocytus sp. (1.6%), Pteromalus sp. (0.5%) (Pteromalidae), and Eupelmus sp. (1.0%) (Eupelmidae). The results from this 3-yr study revealed that chemical control was often reliable in protecting the sunflower crop from stem pests and was relatively insensitive to application timing. Although results in some cases were mixed, overall, delayed planting can be a reliable and effective management tool for growers in the central Plains to use in reducing stem-infesting pest densities in sunflower stalks. Chemical control and planting date were compatible with natural mortality contributed by C. adspersus larval parasitoids.

  16. Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

    Directory of Open Access Journals (Sweden)

    Dian Siswanto

    2013-05-01

    Full Text Available The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N, Cd soils (Cds, and Cd soils each amended with 1% w/w of coir pith (CP, coir pith modified with sodium hydroxide (CPm and corncob (CC under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatments under high cadmium contaminated soil followed the order: Cds > CPm ≥ CP ≥ CC. These transpirations directly influenced cadmium accumulation in shoots and husks of rice plants. The CC and CP seemed to work to reduce the cadmium uptake by rice plants indicated by accumulated cadmium in the husk that were 2.47 and 7.38 mg Cd kg-1 dry weight, respectively. Overall, transpiration tended to drive cadmium accumulation in plants for rice grown in high cadmium contaminated soil. The more that plants uptake cadmium, the lower cadmium that remains in the soil.

  17. Rice Seed Priming with Picomolar Rutin Enhances Rhizospheric Bacillus subtilis CIM Colonization and Plant Growth.

    Science.gov (United States)

    Singh, Akanksha; Gupta, Rupali; Pandey, Rakesh

    2016-01-01

    The effect of rutin, a bioflavonoid on the growth and biofilm formation of Bacillus subtilis strain CIM was investigated. In addition to swimming, swarming, and twitching potentials of B. subtilis CIM (BS), one picomolar (1 pM) of rutin was also observed to boost the biofilm forming ability of the bacterium. Bio-priming of rice seeds with BS and rutin not only augmented root and shoot lengths but also the photosynthetic pigments like chlorophyll and carotenoid. Similarly, high accumulation of phenolic and flavonoid contents was observed in the leaves. Fluorescent microscopic images revealed that BS plus rutin enhanced callose deposition in the leaves. It was also established that the least formation of reactive oxygen species in BS plus rutin treated rice plants was due to higher free radicals scavenging activity and total antioxidant potential. The results highlight chemo attractant nature of BS towards rutin, which by enhancing biofilm formation and root colonization indirectly strengthened the plants' defensive state.

  18. Rice Seed Priming with Picomolar Rutin Enhances Rhizospheric Bacillus subtilis CIM Colonization and Plant Growth.

    Directory of Open Access Journals (Sweden)

    Akanksha Singh

    Full Text Available The effect of rutin, a bioflavonoid on the growth and biofilm formation of Bacillus subtilis strain CIM was investigated. In addition to swimming, swarming, and twitching potentials of B. subtilis CIM (BS, one picomolar (1 pM of rutin was also observed to boost the biofilm forming ability of the bacterium. Bio-priming of rice seeds with BS and rutin not only augmented root and shoot lengths but also the photosynthetic pigments like chlorophyll and carotenoid. Similarly, high accumulation of phenolic and flavonoid contents was observed in the leaves. Fluorescent microscopic images revealed that BS plus rutin enhanced callose deposition in the leaves. It was also established that the least formation of reactive oxygen species in BS plus rutin treated rice plants was due to higher free radicals scavenging activity and total antioxidant potential. The results highlight chemo attractant nature of BS towards rutin, which by enhancing biofilm formation and root colonization indirectly strengthened the plants' defensive state.

  19. Inspections of radiocesium concentration levels in rice from Fukushima Prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M

    2015-03-03

    We summarize the inspections of radiocesium concentration levels in rice produced in Fukushima Prefecture, Japan, for 3 years from the nuclear accident in 2011. In 2011, three types of verifications, preliminary survey, main inspection, and emergency survey, revealed that rice with radiocesium concentration levels over 500 Bq/kg (the provisional regulation level until March 2012 in Japan) was identified in the areas north and west of the Fukushima nuclear power plant. The internal exposure of an average adult eating rice grown in the area north of the nuclear plant was estimated as 0.05 mSv/year. In 2012, Fukushima Prefecture authorities decided to investigate the radiocesium concentration levels in all rice using custom-made belt conveyor testers. Notably, rice with radiocesium concentration levels over 100 Bq/kg (the new standard since April 2012 in Japan) were detected in only 71 and 28 bags out of the total 10,338,000 in 2012 and 11,001,000 in 2013, respectively. We considered that there were almost no rice exceeding 100 Bq/kg produced in Fukushima Prefecture after 3 years from the nuclear accident, and the safety of Fukushima's rice were ensured because of the investigation of all rice.

  20. Temperature Difference Between the Air and Organs of Rice Plant and Its Relation to Spikelet Fertility

    Institute of Scientific and Technical Information of China (English)

    YAN Chuan; DING Yan-feng; LIU Zheng-hui; WANG Qiang-sheng; LI Gang-hua; HE Ying; WANG Shao-hua

    2008-01-01

    Based on the experiment of measuring panicles and leaves, air temperature, and humidity above the canopy of rice cultivars after heading in 2005 and 2006, we investigated the temperature difference (TD) between the air and organs of rice plant and its relationship with spikelet fertility. The results showed that TDs between the air and organs of rice varied with air temperature, air humidity, and plant type. For similar air humidity, TDs were lower at the air temperature of 28.5℃ than at higher temperature of 35.5℃, whereas for the same air temperature, the TDs decreased as the air humidity increased. TDs were also affected by plant type of the cultivars. Erect panicle cultivars showed higher TDs than those with droopy panicles under similar climatic conditions, and cultivars with panicles above flag leaf (PAFL) had higher TDs than those with panicles below the flag leaf (PBFL). Cultivars grown in a location with lower air humidity and higher temperature, such as Taoyuan, China, had higher spikelet fertility than those in higher humidity under the similar air temperature during the grain filling stage. This is partially attributed to the larger TDs under the lower humidity. Row-spacing and the ratio of basal-tillering to panicle-spikelet fertilizer showed a significant influence on TD and subsequently on spikelet fertility, suggesting the possibility of increasing spikelet fertility by agronomic management.

  1. Salt tolerant SUV3 overexpressing transgenic rice plants conserve physicochemical properties and microbial communities of rhizosphere.

    Science.gov (United States)

    Sahoo, Ranjan K; Ansari, Mohammad W; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Key concerns in the ecological evaluation of GM crops are undesirably spread, gene flow, other environmental impacts, and consequences on soil microorganism's biodiversity. Numerous reports have highlighted the effects of transgenic plants on the physiology of non-targeted rhizospheric microbes and the food chain via causing adverse effects. Therefore, there is an urgent need to develop transgenics with insignificant toxic on environmental health. In the present study, SUV3 overexpressing salt tolerant transgenic rice evaluated in New Delhi and Cuttack soil conditions for their effects on physicochemical and biological properties of rhizosphere. Its cultivation does not affect soil properties viz., pH, Eh, organic C, P, K, N, Ca, Mg, S, Na and Fe(2+). Additionally, SUV3 rice plants do not cause any change in the phenotype, species characteristics and antibiotic sensitivity of rhizospheric bacteria. The population and/or number of soil organisms such as bacteria, fungi and nematodes were unchanged in the soil. Also, the activity of bacterial enzymes viz., dehydrogenase, invertase, phenol oxidases, acid phosphatases, ureases and proteases was not significantly affected. Further, plant growth promotion (PGP) functions of bacteria such as siderophore, HCN, salicylic acid, IAA, GA, zeatin, ABA, NH3, phosphorus metabolism, ACC deaminase and iron tolerance were, considerably, not influenced. The present findings suggest ecologically pertinent of salt tolerant SUV3 rice to sustain the health and usual functions of the rhizospheric organisms.

  2. Net ecosystem CO2 exchange of an invasive plant infestation: new insights on the effects of phenology and management practices on structure and functioning

    Science.gov (United States)

    Sonnentag, Oliver; Detto, Matteo; Runkle, Benjamin; Hatala, Jaclyn; Vargas, Rodrigo; Kelly, Maggi; Baldocchi, Dennis

    2010-05-01

    The net ecosystem carbon dioxide (CO2) exchange (FC) of invasive plant infestations has been subject of few studies only. Perennial pepperweed (Lepidium latifolium L.) is an aggressive invasive plant with severe economic and environmental consequences for infested ecosystems. A characteristic feature of pepperweed's phenological cycle is the dense arrangement of small white flowers during secondary inflorescence. Little is known about how pepperweed flowering and management practices such as mowing affect canopy structure and canopy photosynthesis (FA) and autotrophic respiration (FAR) and thus ecosystem respiration (FER; FC=FER-FA with FER=FAR+heterotrophic respiration [FHR]). To examine these effects we analyzed three years (2007-2010) of CO2 flux measurements made with eddy covariance, supporting environmental measurements and near-surface remote sensing data (canopy-scale reflectance, digital camera imagery) from a pepperweed-infested pasture in California's Sacramento-San Joaquin River Delta. The measurements cover three meteorologically similar summers (1 May - 30 September) that slightly differed in terms of land use practices. In 2007-2010, the site was subjected to year-round grazing by beef cattle, and in 2008, the site was additionally mowed in mid-May during flowering. We described structural changes in canopy development through seasonal changes in surface roughness for momentum transfer (z0m). Weekly soil CO2 efflux (≈ FHR) estimates from static chamber measurements made over bare soil were used to separate FER into FAR and FHR. We identified the onset of pepperweed's key phenological phases (i.e., germination, early vegetative growth, flowering, seed maturation, senescence, dormancy) through the integrated analysis of albedo of photosynthetically active radiation (PAR), a broad-band green normalized difference vegetation index, and a digital camera-based color index. We used non-linear mixed-effects model analysis to investigate the combined

  3. Analysis and Simulation of Plant Type on Canopy Structure and Radiation Transmission in Rice

    Institute of Scientific and Technical Information of China (English)

    HU Ning; LU Chuan-gen; YAO Ke-min; CHEN Jing; ZHANG Xiao-cui

    2013-01-01

    Three typical hybrid rice cultivars,together with three artificially modified plant types by the application of N fertilizer during the elongation of the two uppermost leaves were used to analyze how the plant type affected the layered leaf area and radiation transmission.Plant type factors,layered leaf area and radiation distribution were measured at the full heading,10 d and 25 d after full heading stages,respectively.A model for calculating the layered leaf area from plant type factors was established and validated to determine the effects of plant type factors on the layered leaf area for the three hybrids.Furthermore,the relationship between layered leaf area and radiation transmission was established by using the radiation transmission model.The effects of the plant type factors on the radiation transmission for the three hybrids were evaluated by using this model.Finally,a method was established to describe the canopy structure,such as the layered leaf area index and the radiation distribution in the rice canopy.

  4. Expression of peanut Iron Regulated Transporter 1 in tobacco and rice plants confers improved iron nutrition.

    Science.gov (United States)

    Xiong, Hongchun; Guo, Xiaotong; Kobayashi, Takanori; Kakei, Yusuke; Nakanishi, Hiromi; Nozoye, Tomoko; Zhang, Lixia; Shen, Hongyun; Qiu, Wei; Nishizawa, Naoko K; Zuo, Yuanmei

    2014-07-01

    Iron (Fe) limitation is a widespread agricultural problem in calcareous soils and severely limits crop production. Iron Regulated Transporter 1 (IRT1) is a key component for Fe uptake from the soil in dicot plants. In this study, the peanut (Arachis hypogaea L.) AhIRT1 was introduced into tobacco and rice plants using an Fe-deficiency-inducible artificial promoter. Induced expression of AhIRT1 in tobacco plants resulted in accumulation of Fe in young leaves under Fe deficient conditions. Even under Fe-excess conditions, the Fe concentration was also markedly enhanced, suggesting that the Fe status did not affect the uptake and translocation of Fe by AhIRT1 in the transgenic plants. Most importantly, the transgenic tobacco plants showed improved tolerance to Fe limitation in culture in two types of calcareous soils. Additionally, the induced expression of AhIRT1 in rice plants also resulted in high tolerance to low Fe availability in calcareous soils.

  5. Gene expression analysis in rice plants after external radiation exposure in Iitate village

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, G.; Fukumoto, M. [Institute of Development, Aging and Cancer, Tohoku University (Japan); Imanaka, T. [Research Reactor Institute, Kyoto University (Japan); Shibato, J. [Department of Anatomy I, School of Medicine, Showa University (Japan); Kubo, A. [Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies (Japan); Kikuchi, S. [Plant Genome Research Unit, Agrogenomics Research Center, National Institute of Agrobiological Sciences (Japan); Rakwal, R. [Organization for Educational Initiatives, University of Tsukuba (Japan)

    2014-07-01

    Rice plants exposed to radiation respond to the stress by activating self-defense mechanisms. A well-established molecular approach to measure stress is by cataloging global gene expression profiles. Here, we examined the effect of radiation exposure in a cereal crop model plant - rice (Oryza sativa L.) cultivar Nipponbare - in the village of Iitate of Fukushima prefecture. Iitate village is a highly radio-contaminated site due to the Fukushima Daiichi nuclear power plant accident following the Great East Japan Earthquake. The experimental approach comprised of five steps. First, healthy rice seedlings were grown in the greenhouse facility at National Institute for Environmental Sciences. Post-germination at 30 deg. C similarly germinated seeds were placed in neat rows in seedling pots having commercial soil (JA Zen-Noh, Japan; http//www.zennoh.or.jp/) with recommended NPK (nitrogen, phosphorus, and potash) doses at a controlled (25 deg. C, 70% relative humidity and natural light condition) greenhouse. Second, the seedlings were transported from a controlled greenhouse in Tsukuba to Iitate Farm (ITF) and placed, with no direct contact with soil, in a low-level gamma field where the rate of Cs-137 was 700 kBq/m{sup 2}. Third, exposure periods were set at 6, 12, 24, 48, and 72 h after arrival at ITF, and rice leaves at the 3. position (from the base) from 6 to 10 seedlings were sampled in dry ice. As control, rice leaves were sampled at the start in Tsukuba and immediately at arrival upon ITF; to know the radiation levels during growth and transport of the rice to ITF, accumulated radiation dose was calculated using a MYDOSE mini electronic pocket dosimeter (model PDM-222-52, ALOKA, Japan). A sample set was also taken at 72 h from healthy rice seedlings in the greenhouse at Tsukuba. All samples were stored at -80 deg. C. Accumulated total dose for exposed rice seedlings at 72 h was 200 mSv. Fourth, gene expression analysis was initiated by grinding the leaves to a

  6. Transgenic rice plants harboring the grain hardness-locus region of Aegilops tauschii.

    Science.gov (United States)

    Suzuki, Go; Wada, Hideo; Goto, Hiromi; Nakano, Akiko; Oba, Haruna; Deno, Takuya; Rahman, Sadequr; Mukai, Yasuhiko

    2011-12-01

    Grain hardness of wheat is determined by the hardness (Ha)-locus region, which contains three friabilin-related genes: puroindoline-a (Pina), puroindoline-b (Pinb) and GSP-1. In our previous study, we produced the transgenic rice plants harboring the large genomic fragment of the Ha-locus region of Aegilops tauschii containing Pina and GSP-1 genes by Agrobacterium-mediated transformation. To examine the effects of the transgenes in the rice endosperms, we firstly confirmed the homozygosity of the T-DNAs in four independent T2 lines by using fluorescence in situ hybridization (FISH) and DNA gel blot analyses. The transgenes, Pina and GSP-1, were stably expressed in endosperms of the T3 and T4 seeds at RNA and protein levels, indicating that the promoters and other regulatory elements on the wheat Ha-locus region function in rice, and that multigene transformation using a large genomic fragment is a useful strategy. The functional contribution of the transgene-derived friabilins to the rice endosperm structure was considered as an increase of spaces between compound starch granules, resulting in a high proportion of white turbidity seeds.

  7. Study on allelopathic effects of Rice and Wheat Soil-Like Substrate on several plants

    Science.gov (United States)

    Li, Leyuan; Fu, Wenting; He, Wenting; Liu, Hong

    Rice and wheat are the traditional food of Chinese people, and therefore the main crop candidates for bio-regenerative life-support systems. Recycling rice and wheat straw is an important issue concerning the system. In order to decide if the mixed-substrate made of rice and wheat straw is suitable of plant cultivation, Rice and Wheat Soil-Like Substrate was tested in an aqueous extract germination experiment. The effects of different concentrations of aqueous extract on seed vigor, seedling growth and development situations and the physiological and biochemical characteristics of wheat, lettuce and pumpkin were studied, and the presence and degrees of allelopathic effects were analyzed. The test results showed that this type of SLS exerted different degrees of allelopathic effect on wheat and lettuce; this allelopathic effect was related to the concentration of SLS aqueous extract. The most significant phenomenon is that with the increase of aqueous extract concentration, the seed germination, root length and shoot fresh weight of wheat decreased; and every concentration of aqueous extract showed significant inhibition on the root length and root fresh weight of lettuce. However, this type of SLS showed little effect on the growth of pumpkin seedlings. Contents changes of chlorophyll and endogenous hormones in wheat and lettuce seedlings, and the chemical compositions of SLS were measured, and the mechanism of allelopathic effect was preliminarily analyzed.

  8. Regulation of OsSPL14 by OsmiR156 defines ideal plant architecture in rice.

    Science.gov (United States)

    Jiao, Yongqing; Wang, Yonghong; Xue, Dawei; Wang, Jing; Yan, Meixian; Liu, Guifu; Dong, Guojun; Zeng, Dali; Lu, Zefu; Zhu, Xudong; Qian, Qian; Li, Jiayang

    2010-06-01

    Increasing crop yield is a major challenge for modern agriculture. The development of new plant types, which is known as ideal plant architecture (IPA), has been proposed as a means to enhance rice yield potential over that of existing high-yield varieties. Here, we report the cloning and characterization of a semidominant quantitative trait locus, IPA1 (Ideal Plant Architecture 1), which profoundly changes rice plant architecture and substantially enhances rice grain yield. The IPA1 quantitative trait locus encodes OsSPL14 (SOUAMOSA PROMOTER BINDING PROTEIN-LIKE 14) and is regulated by microRNA (miRNA) OsmiR156 in vivo. We demonstrate that a point mutation in OsSPL14 perturbs OsmiR156-directed regulation of OsSPL14, generating an 'ideal' rice plant with a reduced tiller number, increased lodging resistance and enhanced grain yield. Our study suggests that OsSPL14 may help improve rice grain yield by facilitating the breeding of new elite rice varieties.

  9. Plants regenerated from tissue culture contain stable epigenome changes in rice.

    Science.gov (United States)

    Stroud, Hume; Ding, Bo; Simon, Stacey A; Feng, Suhua; Bellizzi, Maria; Pellegrini, Matteo; Wang, Guo-Liang; Meyers, Blake C; Jacobsen, Steven E

    2013-03-19

    Most transgenic crops are produced through tissue culture. The impact of utilizing such methods on the plant epigenome is poorly understood. Here we generated whole-genome, single-nucleotide resolution maps of DNA methylation in several regenerated rice lines. We found that all tested regenerated plants had significant losses of methylation compared to non-regenerated plants. Loss of methylation was largely stable across generations, and certain sites in the genome were particularly susceptible to loss of methylation. Loss of methylation at promoters was associated with deregulated expression of protein-coding genes. Analyses of callus and untransformed plants regenerated from callus indicated that loss of methylation is stochastically induced at the tissue culture step. These changes in methylation may explain a component of somaclonal variation, a phenomenon in which plants derived from tissue culture manifest phenotypic variability. DOI:http://dx.doi.org/10.7554/eLife.00354.001.

  10. Damage of Rhopalosiphum padi (L.) (Hemiptera: Aphididae) on wheat plants related to duration time and density of infestation; Danos de Rhopalosiphum padi (L.) (Hemiptera: Aphididae) no trigo em funcao da duracao e da densidade de infestacao

    Energy Technology Data Exchange (ETDEWEB)

    Roza-Gomes, Margarida F. [Rua Pedro Roso, 42, Nonoai, RS, (Brazil)]. E-mail: margafrg@brturbo.com.br; Salvadori, Jose R. [Embrapa Trigo, Passo Fundo, RS (Brazil)]. E-mail: jrsalva@cnpt.embrapa.b; Schons, Jurema [Universidade de Passo Fundo, RS (Brazil). Fac. de Agronomia e Medicina Veterinaria]. E-mail: schons@upf.br

    2008-09-15

    Aphids are considered relevant pests on wheat either by direct damage through sap sucking or by indirect damage vectoring BYDV (Barley yellow dwarf virus). Rhopalosiphum padi L. has been observed infesting wheat fields with an increasing frequency. The knowledge and the available technology, besides being more related to other aphids species already recognized as pests, they are insufficient to control the specific c problem of R. padi. Thus, this work evaluated the effects of feeding duration and infestation densities of R. padi on seedlings of wheat cv. EMBRAPA 16. rain yield, yield components and the extent of symptoms were recorded. The experiment was carried out in the fi eld under a completely randomized split-plot experimental design with four replications. The main plot was feeding duration (two and seven days) and the sub-plots were infestation densities (zero, two and 10 aphids per plant). Independent on feeding duration, 10 aphids per plant resulted in significant yield losses, reduction of number of heads and tillers per plant. Canopy dry matter was also reduced. Infestations of two and 10 aphids per plant resulted in continuous yellowing of wheat plants from tillering to the end of flowering stage. When aphids fed for seven days on wheat, more yellowing symptoms were observed at the flower stage in comparison with two days feeding. (author)

  11. Introduction of cecropin B gene into rice (Oryza sativa L.) by particle bombardment and analysis of transgenic plants

    Institute of Scientific and Technical Information of China (English)

    黄大年; 朱冰; 杨炜; 薛锐; 肖晗; 田文忠; 李良材; 戴顺洪

    1996-01-01

    An expression vector pCBl suitable for rice transformation, harboring a synthesized cecropin B gene and a selectable marker gene (bar), was constructed. It was introduced into immature embryos of two japonica varieties by particle bombardment, and several transgenic plants were obtained. The results from Basta treatment, PCR analysis, dot and Southern blot analysis of cecropin B gene in transgenic plants indicated that both bar and cecropin B gene were integrated into the genome of transformed plants. Northern blot analysis of transgenic plants showed the expression of cecropin B gene at transcriptional level. Some of transgenic plants revealed improved resistances to two types of bacterial diseases, rice bacterial blight and rice bacterial streak to different extent.

  12. Over-expression of PsGPD, a mushroom glyceraldehyde-3-phosphate dehydrogenase gene, enhances salt tolerance in rice plants.

    Science.gov (United States)

    Cho, Jung-Il; Lim, Hye-Min; Siddiqui, Zamin Shaheed; Park, Sung-Han; Kim, A-Ram; Kwon, Taek-Ryoun; Lee, Seong-Kon; Park, Soo-Chul; Jeong, Mi-Jeong; Lee, Gang-Seob

    2014-08-01

    Transgenic potatoes expressing glyceraldehyde-3-phosphate dehydrogenase (GPD), isolated from the oyster mushroom, Pleurotus sajor-caju, had increased tolerance to salt stress (Jeong et al. Biochem Biophys Res Commun 278:192-196, 2000). To examine the physiological mechanisms enhancing salt tolerance in GPD-transgenic rice plants, the salt tolerance of five GPD transgenic rice lines (T1-T5) derived from Dongjin rice cultivar were evaluated in a fixed 150 mM saline environment in comparison to two known wild-type rice cultivars, Dongjin (salt sensitive) and Pokali (salt tolerant). Transgenic lines, T2, T3, and T5, had a substantial increase in biomass and relative water content compared to Dongjin. Stomatal conductance and osmotic potential were higher in the GPD transgenic lines and were similar to those in Pokali. The results are discussed based on the comparative physiological response of GPD transgenic lines with those of the salt-sensitive and salt-tolerant rice cultivars.

  13. The Role of Antioxidant Enzymes in Adaptive Responses to Sheath Blight Infestation under Different Fertilization Rates and Hill Densities

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2014-01-01

    Full Text Available Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD, peroxidase (POD, and catalase (CAT and malondialdehyde content (MDA responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development.

  14. Detection of BPH (brown planthopper sheath blight in rice farming using multispectral remote sensing

    Directory of Open Access Journals (Sweden)

    Faranak Ghobadifar

    2016-01-01

    Full Text Available Sustainable pest controlling method is essential in producing rice, one of the most important food staples worldwide, which is globally under concern of either farmers or consumers. Infestation of rice plant hopper such as brown planthopper (BPH (Nilaparvata lugens is one of the most notable risks in rice yield in tropical areas especially in Asia. In order to use visible and infrared images to detect stress in rice production caused by BPH infestation, several remote sensing techniques have been developed. Initial recognition of pest infestation by means of remote sensing will (1 decrease food production costs, (2 limit environmental hazards, and (3 enhance natural pest control before the problem spreads, for precision farming procedures. In this paper, detection of sheath blight was examined using SPOT (Satellite Pour l'Observation de la Terre-5 images as the main data. Analyses were undertaken using ENVI (Environment for Visualizing Images 4.8 and SPSS software. As a result, there was variety for the images of both early and late growing seasons. Specific image indices, such as RVI14, SDI14 and SDI24, proved better association for detecting healthy plants from diseased ones. These sorts of indices could be recognized as a valued indicator for developing techniques in order to detect the sheath blight of rice by means of remote sensing.

  15. Result of Six Local Upland Rice Cultivars of East Kalimantan at Different Plant Spacing

    Directory of Open Access Journals (Sweden)

    R. Rusdiansyah

    2013-06-01

    Full Text Available The objective of this research was to evaluate the response of six upland rice cultivars from East Kalimantan over different plant spacing. The experiment was conducted at Kutai Kartanegara district in East Kalimantan, Indonesia. The experimental design used was the factorial experiment in Randomized Completely Block Design (RCDB with three replications. The first factor was six upland rice cultivars of East Kalimantan, i.e.: v1 (Mayas Pancing, v2 (Gedagai, v3 (Bogor Putih, v4 (Mayas Putih, v5 (Serai and v6 (Kunyit. The second factor was plant spacing i.e.: j1 (20 x 20 cm and j2 (30 x 30 cm. The results showed that among the six cultivars, Gedagai, Bogor Putih and Kunyit produced higher yield than other varieties.  Gedagai and Bogor Putih cultivars produced higher yield of 2.99 ton ha-1 at plant spacing 20 x 20 cm, whereas Kunyit produced higher yield of 2.66 ton ha-1 at plant spacing 30 x 30 cm. The agronomic characters showed that plant height of the six cultivars differed significantly at harvest time. In addition, highly significant differences of harvest time were observed of the six cultivars.Doi: http://dx.doi.org/10.12777/ijse.4.2.2013.66-68

  16. Isolation and characterization of plant growth promoting endophytic diazotrophic bacteria from Korean rice cultivars.

    Science.gov (United States)

    Ji, Sang Hye; Gururani, Mayank Anand; Chun, Se-Chul

    2014-01-20

    We have isolated 576 endophytic bacteria from the leaves, stems, and roots of 10 rice cultivars and identified 12 of them as diazotrophic bacteria using a specific primer set of nif gene. Through 16S rDNA sequence analysis, nifH genes were confirmed in the two species of Penibacillus, three species of Microbacterium, three Bacillus species, and four species of Klebsiella. Rice seeds treated with these plant growth-promoting bacteria (PGPB) showed improved plant growth, increased height and dry weight and antagonistic effects against fungal pathogens. In addition, auxin and siderophore producing ability, and phosphate solubilizing activity were studied for the possible mechanisms of plant growth promotion. Among 12 isolates tested, 10 strains have shown higher auxin producing activity, 6 isolates were confirmed as strains with high siderophore producing activity while 4 isolates turned out to have high phosphate-solubilizing activity. These results strongly suggest that the endophytic diazotrophic bacteria characterized in this study could be successfully used to promote plant growth and inducing fungal resistance in plants.

  17. Comparative Analysis on Rice Plant Type of Two Super Hybrids and Shanyou63

    Institute of Scientific and Technical Information of China (English)

    LU Chuan-gen; ZOU Jiang-shi

    2003-01-01

    The characteristics of plant type and physiological indices for photosynthesis were analyzedusing two super hybrid rices, Liangyoupeijiu and LiangyouE32 as materials, and an indica hybrid, Shan-you63 as a control. Based on the present analysis and various theories and breeding practices on rice planttype, a model of plant ideotype for super hybrid rice (indica) in the lower reaches of Yangtze River Valleywas proposed. This was: a length of 35 - 40 cm for top leaf with a width of 2 cm, and that of 50 - 55 cmand 55 - 60 crm, respectively, for the second and third leaves from top, meanwhile, having a leaf angle of5°, 10° and 15° respectively, and a curvature of 1 - 1.5 cm-1 for the leaf face at heading stage; the upper-most three leaves keeping their activities for as long as 70 d, which could lead a LAI of 3 at full ripeness;loose plant type with thin (SLW=2.5- 3 gcm-2 , dry weight) and curve-slant leaves during early growingstage, and compact plant type by thick (SLW = 4 - 5 gcm-2 ) and erect leaves during the middle and lategrowing stages; with a coefficient of light extinction of 0.3 - 0.4, which allowed for an optimal LAI high of8 - 10 during the middle growth period; plant height of 110 -120 cm, with 2 -4 cm basal internode and along uppermost internode occupying 45 % of total stem length; 25 - 28 cm panicle with 8 - 10 spikelets percentimeter showing bend-type in ripening; a rich chlorophyll which led to a high net photosynthetic rate,and tolerance to light shading and photooxidation which is of benefit to increasing the adaptability to varyinglight conditions.

  18. Composting rice straw with sewage sludge and compost effects on the soil-plant system.

    Science.gov (United States)

    Roca-Pérez, L; Martínez, C; Marcilla, P; Boluda, R

    2009-05-01

    Composting organic residue is an interesting alternative to recycling waste as the compost obtained may be used as organic fertilizer. This study aims to assess the composting process of rice straw and sewage sludge on a pilot-scale, to evaluate both the quality of the composts obtained and the effects of applying such compost on soil properties and plant development in pot experiments. Two piles, with shredded and non-shredded rice straw, were composted as static piles with passive aeration. Throughout the composting process, a number of parameters were determined, e.g. colour, temperature, moisture, pH, electrical conductivity, organic matter, C/N ratio, humification index, cation exchange capacity, chemical oxygen demand, and germination index. Moreover, sandy and clayey soils were amended with different doses of mature compost and strewed with barley in pot experiments. The results show that compost made from shredded rice straw reached the temperatures required to maximise product sanitisation, and that the parameters indicating compost maturity were all positive; however, the humification index and NH(4) content were more selective. Therefore, using compost-amended soils at a dose of 34 Mg ha(-1) for sandy soil, and of 11 Mg ha(-1) for clayey soil improves soil properties and the growth of Hordeum vulgare plants. Under there conditions, the only limiting factor of agronomic compost utilisation was the increased soil salinity.

  19. VERTICAL LEAF SPECTRAL VARIATION AS AN INDICATOR OF NITROGEN NUTRITION STATUS IN RICE PLANTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A field experiment was conducted to study the response of individual leaf spectral reflectance to five levels of nitrogen fertilizer treatments in rice(Oriza sativa L.) plants. Sampling was combined through a rice canopy at upper, medium and low levels for biomass, nitrogen and water content measurements with spectral signals from the leaves. The vertical gradients of leaf biomass ,nitrogen and water contents were associated with the nitrogen availability during tillering, panicle formation, initial heading and heading. Rice plants treated with the lowest rate of N could be characterized with the lowest value of gradient in leaf biomass and leaf water content and the highest value of gradient in leaf N concentration. A spectral gradient of single reflectance(R),ratio(RVI) and normalized difference(ND) of two individual reflectances was defined as this yielded a better relationship between the spectral data and leaf nitrogen concentration. The results suggested the spectral gradients may be used as an improved diagnostic tool for nitrogen status.

  20. Studies in an atmospheric bubbling fluidized-bed combustor of 10 MW power plant based on rice husk

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ravi Inder [Department of Mechanical Engineering, Guru Nanak Dev Engineering College, Ludhiana, Punjab 141 006 (India); Mohapatra, S.K. [Department of Mechanical Engineering, Thapar University, Patiala, Punjab (India); Gangacharyulu, D. [Department of Chemical Engineering, Thapar University, Patiala, Punjab (India)

    2008-11-15

    In this paper an experience, environmental assessment, a model for exit gas composition, agglomeration problem and a model for solid population balance of 10 MW power plant at Jalkheri, Distt. Fatehgarh Sahib, Punjab, India based on rice husk has been discussed. Three phase multistage mathematical model for exit gas composition of rice husk in fluidized bed has been derived. The model is based on three-phase theory of fluidization and material balance for shrinking rice husk particles and it is similar to model developed by Kunii and Levenspiel. The burning of rice husk is assumed to take place according to single film theory. The model has been used to predict the exit gas composition particularly O{sub 2}, CO{sub 2} and N{sub 2}. The agglomeration problem of above plant which is main reason for defluidization of bed has also been discussed. SEM of ash agglomerates has been done. Ash samples taken from the above 10 MW power plant at Jalkheri has been quantitatively analyzed. Finally solid population model has been formed to calculate bed carbon load and carbon utilization efficiency. Above two models are experimentally correlated with the data collected from the above 10 MW power plant at Jalkheri, Distt. Fatehgarh Sahib, Punjab, India which uses rice husk as a fuel input (at the time of study). All the results from the model for rice husk are coming with in permissible limits. (author)

  1. Pesticide productivity, host-plant resistance and productivity in China

    OpenAIRE

    Widawsky, David; Rozelle, Scott; Jin, Songqing; Huang, Jikun

    1998-01-01

    Pesticides are used as the primary method of pest control in Asian rice production. Conditions in China have led to demand for high and increasing rice yields, resulting in intensive cultivation and adoption of fertilizer responsive varieties. The consequence has been widespread pest infestations. Many studies have estimated pesticide productivity, but few have estimated the productivity of alternative methods of pest control, namely host-plant resistance. None have estimated the substitutabi...

  2. Overproduction of C4 photosynthetic enzymes in transgenic rice plants: an approach to introduce the C4-like photosynthetic pathway into rice.

    Science.gov (United States)

    Taniguchi, Yojiro; Ohkawa, Hiroshi; Masumoto, Chisato; Fukuda, Takuya; Tamai, Tesshu; Lee, Kwanghong; Sudoh, Sizue; Tsuchida, Hiroko; Sasaki, Haruto; Fukayama, Hiroshi; Miyao, Mitsue

    2008-01-01

    Four enzymes, namely, the maize C(4)-specific phosphoenolpyruvate carboxylase (PEPC), the maize C(4)-specific pyruvate, orthophosphate dikinase (PPDK), the sorghum NADP-malate dehydrogenase (MDH), and the rice C(3)-specific NADP-malic enzyme (ME), were overproduced in the mesophyll cells of rice plants independently or in combination. Overproduction individually of PPDK, MDH or ME did not affect the rate of photosynthetic CO(2) assimilation, while in the case of PEPC it was slightly reduced. The reduction in CO(2) assimilation in PEPC overproduction lines remained unaffected by overproduction of PPDK, ME or a combination of both, however it was significantly restored by the combined overproduction of PPDK, ME, and MDH to reach levels comparable to or slightly higher than that of non-transgenic rice. The extent of the restoration of CO(2) assimilation, however, was more marked at higher CO(2) concentrations, an indication that overproduction of the four enzymes in combination did not act to concentrate CO(2) inside the chloroplast. Transgenic rice plants overproducing the four enzymes showed slight stunting. Comparison of transformants overproducing different combinations of enzymes indicated that overproduction of PEPC together with ME was responsible for stunting, and that overproduction of MDH had some mitigating effects. Possible mechanisms underlying these phenotypic effects, as well as possibilities and limitations of introducing the C(4)-like photosynthetic pathway into C(3) plants, are discussed.

  3. Increase of Fungal Pathogenicity and Role of Plant Glutamine in Nitrogen-Induced Susceptibility (NIS) To Rice Blast

    Science.gov (United States)

    Huang, Huichuan; Nguyen Thi Thu, Thuy; He, Xiahong; Gravot, Antoine; Bernillon, Stéphane; Ballini, Elsa; Morel, Jean-Benoit

    2017-01-01

    Highlight  Modifications in glutamine synthetase OsGS1-2 expression and fungal pathogenicity underlie nitrogen-induced susceptibility to rice blast. Understanding why nitrogen fertilization increase the impact of many plant diseases is of major importance. The interaction between Magnaporthe oryzae and rice was used as a model for analyzing the molecular mechanisms underlying Nitrogen-Induced Susceptibility (NIS). We show that our experimental system in which nitrogen supply strongly affects rice blast susceptibility only slightly affects plant growth. In order to get insights into the mechanisms of NIS, we conducted a dual RNA-seq experiment on rice infected tissues under two nitrogen fertilization regimes. On the one hand, we show that enhanced susceptibility was visible despite an over-induction of defense gene expression by infection under high nitrogen regime. On the other hand, the fungus expressed to high levels effectors and pathogenicity-related genes in plants under high nitrogen regime. We propose that in plants supplied with elevated nitrogen fertilization, the observed enhanced induction of plant defense is over-passed by an increase in the expression of the fungal pathogenicity program, thus leading to enhanced susceptibility. Moreover, some rice genes implicated in nitrogen recycling were highly induced during NIS. We further demonstrate that the OsGS1-2 glutamine synthetase gene enhances plant resistance to M. oryzae and abolishes NIS and pinpoint glutamine as a potential key nutrient during NIS. PMID:28293247

  4. Photosynthesis is induced in rice plants that associate with arbuscular mycorrhizal fungi and are grown under arsenate and arsenite stress.

    Science.gov (United States)

    de Andrade, Sara Adrian Lopez; Domingues, Adilson Pereira; Mazzafera, Paulo

    2015-09-01

    The metalloid arsenic (As) increases in agricultural soils because of anthropogenic activities and may have phytotoxic effects depending on the available concentrations. Plant performance can be improved by arbuscular mycorrhiza (AM) association under challenging conditions, such as those caused by excessive soil As levels. In this study, the influence of AM on CO2 assimilation, chlorophyll a fluorescence, SPAD-chlorophyll contents and plant growth was investigated in rice plants exposed to arsenate (AsV) or arsenite (AsIII) and inoculated or not with Rhizophagus irregularis. Under AsV and AsIII exposure, AM rice plants had greater biomass accumulation and relative chlorophyll content, increased water-use efficiency, higher carbon assimilation rate and higher stomatal conductance and transpiration rates than non-AM rice plants did. Chlorophyll a fluorescence analysis revealed significant differences in the response of AM-associated and -non-associated plants to As. Mycorrhization increased the maximum and actual quantum yields of photosystem II and the electron transport rate, maintaining higher values even under As exposure. Apart from the negative effects of AsV and AsIII on the photosynthetic rates and PSII efficiency in rice leaves, taken together, these results indicate that AM is able to sustain higher rice photosynthesis efficiency even under elevated As concentrations, especially when As is present as AsV.

  5. [Effects of ozone stress on photosynthesis and dry matter production of rice II -you 084 under different Planting densities].

    Science.gov (United States)

    Peng, Bin; Lai, Shang-kun; Li, Pan-lin; Wang, Yun-xia; Zhu, Jian-guo; Yang, Lian-xin; Wang, Yu-long

    2015-01-01

    In order to investigate the effects of ozone stress on photosynthesis, dry matter production, non-structural carbohydrate and yield formation of rice, a free air ozone concentration enrichment (FACE) experiment was conducted. A super hybrid rice cultivar II-you 084 with 3 spacing levels, low plant density (LD, 16 hills per m2), medium (MD, 24 hills per m2) and high plant density (HD, 32 hills per m2), was grown in the field at current and elevated ozone concentrations (current × 1.5). The results were as follows: Elevated ozone significantly reduced leaf SPAD value of UI-you 084 by 6%, 11% and 13%, at 63, 77, and 86 days after transplanting, respectively. The declines in leaf net photosynthetic rate, stomatal conductance and transpiration rate at filling stage increased significantly on ozone stress over time. Ozone stress decreased dry matter production of rice by 46% from heading stage to plant maturity, thus reduced biomass yield by 25%. Elevated ozone decreased the concentration and accumulation of soluble carbohydrate and starch in stem of II-you 084 at jointing, heading and plant maturity, but significantly increased the dry matter transportation rate. No significant interaction was observed between ozone and planting density for photosynthesis, dry matter production and non-structural carbohydrate of rice. The above results indicated that elevated ozone reduced photosynthesis and growth of rice II-you 084 at late growth stage, which had no relationship with planting density.

  6. Gasification of agricultural residues in a demonstrative plant: Vine pruning and rice husks.

    Science.gov (United States)

    Biagini, Enrico; Barontini, Federica; Tognotti, Leonardo

    2015-10-01

    Tests with vine pruning and rice husks were carried out in a demonstrative downdraft gasifier (350 kW), to prove the reactor operability, quantify the plant efficiency, and thus extend the range of potential energy feedstocks. Pressure drops, syngas flow rate and composition were monitored to study the material and energy balances, and performance indexes. Interesting results were obtained for vine pruning (syngas heating value 5.7 MJ/m(3), equivalent ratio 0.26, cold gas efficiency 65%, power efficiency 21%), while poorer values were obtained for rice husks (syngas heating value 2.5-3.8 MJ/m(3), equivalent ratio 0.4, cold gas efficiency 31-42%, power efficiency 10-13%). The work contains also a comparison with previous results (wood pellets, corn cobs, Miscanthus) for defining an operating diagram, based on material density and particle size and shape, and the critical zones (reactor obstruction, bridging, no bed buildup, combustion regime).

  7. Correlation of Plant Morphological and Grain Quality Traits with Mineral Element Contents in Yunnan Rice

    Institute of Scientific and Technical Information of China (English)

    ZENG Ya-wen; SHEN Shi-quan; WANG Lu-xiang; LIU Jia-fu; PU Xiao-ying; DU Juan; QIU Min

    2005-01-01

    Correlations between four grain quality, 24 plant morphological traits and eight element contents of 653 accessions fromYunnan rice were analyzed. P, K, Ca and Mg contents of core collection were closely correlated to the most plant morphologicaland grain quality traits, and there were highly significant correlations (P <0.01) among some traits including P content to number ofstems and tillers, K content and amylose content, Ca content and plant height, Mg content and protein content. Mn, Zn, Cu and Fecontents of core collection were closely related to a few traits, such as Fe content and gel consistency (-0.1121 **), Zn content andseed setting rate (-0.1411 **), Cu content and number of grains per panicle (-0.1398**), Mn content and plant height (-0.2492**).

  8. Effects of compost and chicken litter on soil nutrition, and sugarcane physiochemistry, yield, and injury caused by Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae)

    Science.gov (United States)

    Levels of Mexican rice borer, Eoreuma loftini (Dyar), infestation in sugarcane have been shown to be heavily influenced by drought stress on the plants, but the effects of soil quality have not been determined. Soil enrichment with two rates of compost and chicken litter were compared with conventio...

  9. Effects of nitrogen form on growth, CO₂ assimilation, chlorophyll fluorescence, and photosynthetic electron allocation in cucumber and rice plants.

    Science.gov (United States)

    Zhou, Yan-hong; Zhang, Yi-li; Wang, Xue-min; Cui, Jin-xia; Xia, Xiao-jian; Shi, Kai; Yu, Jing-quan

    2011-02-01

    Cucumber and rice plants with varying ammonium (NH(4)(+)) sensitivities were used to examine the effects of different nitrogen (N) sources on gas exchange, chlorophyll (Chl) fluorescence quenching, and photosynthetic electron allocation. Compared to nitrate (NO(3)(-))-grown plants, cucumber plants grown under NH(4)(+)-nutrition showed decreased plant growth, net photosynthetic rate, stomatal conductance, intercellular carbon dioxide (CO(2)) level, transpiration rate, maximum photochemical efficiency of photosystem II, and O(2)-independent alternative electron flux, and increased O(2)-dependent alternative electron flux. However, the N source had little effect on gas exchange, Chl a fluorescence parameters, and photosynthetic electron allocation in rice plants, except that NH(4)(+)-grown plants had a higher O(2)-independent alternative electron flux than NO(3)(-)-grown plants. NO(3)(-) reduction activity was rarely detected in leaves of NH(4)(+)-grown cucumber plants, but was high in NH(4)(+)-grown rice plants. These results demonstrate that significant amounts of photosynthetic electron transport were coupled to NO(3)(-) assimilation, an effect more significant in NO(3)(-)-grown plants than in NH(4)(+)-grown plants. Meanwhile, NH(4)(+)-tolerant plants exhibited a higher demand for the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) for NO(3)(-) reduction, regardless of the N form supplied, while NH(4)(+)-sensitive plants had a high water-water cycle activity when NH(4)(+) was supplied as the sole N source.

  10. Mitochondrial GPX1 silencing triggers differential photosynthesis impairment in response to salinity in rice plants.

    Science.gov (United States)

    Lima-Melo, Yugo; Carvalho, Fabricio E L; Martins, Márcio O; Passaia, Gisele; Sousa, Rachel H V; Neto, Milton C Lima; Margis-Pinheiro, Márcia; Silveira, Joaquim A G

    2016-08-01

    The physiological role of plant mitochondrial glutathione peroxidases is scarcely known. This study attempted to elucidate the role of a rice mitochondrial isoform (GPX1) in photosynthesis under normal growth and salinity conditions. GPX1 knockdown rice lines (GPX1s) were tested in absence and presence of 100 mM NaCl for 6 d. Growth reduction of GPX1s line under non-stressful conditions, compared with non-transformed (NT) plants occurred in parallel to increased H2 O2 and decreased GSH contents. These changes occurred concurrently with photosynthesis impairment, particularly in Calvin cycle's reactions, since photochemical efficiency did not change. Thus, GPX1 silencing and downstream molecular/metabolic changes modulated photosynthesis differentially. In contrast, salinity induced reduction in both phases of photosynthesis, which were more impaired in silenced plants. These changes were associated with root morphology alterations but not shoot growth. Both studied lines displayed increased GPX activity but H2 O2 content did not change in response to salinity. Transformed plants exhibited lower photorespiration, water use efficiency and root growth, indicating that GPX1 could be important to salt tolerance. Growth reduction of GPX1s line might be related to photosynthesis impairment, which in turn could have involved a cross talk mechanism between mitochondria and chloroplast originated from redox changes due to GPX1 deficiency.

  11. Genome-wide profiling of genetic variation in Agrobacterium-transformed rice plants*#

    Science.gov (United States)

    Li, Wen-xu; Wu, San-ling; Liu, Yan-hua; Jin, Gu-lei; Zhao, Hai-jun; Fan, Long-jiang; Shu, Qing-yao

    2016-01-01

    Agrobacterium-mediated transformation has been widely used in producing transgenic plants, and was recently used to generate “transgene-clean” targeted genomic modifications coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas9) system. Although tremendous variation in morphological and agronomic traits, such as plant height, seed fertility, and grain size, was observed in transgenic plants, the underlying mechanisms are not yet well understood, and the types and frequency of genetic variation in transformed plants have not been fully disclosed. To reveal the genome-wide variation in transformed plants, we sequenced the genomes of five independent T0 rice plants using next-generation sequencing (NGS) techniques. Bioinformatics analyses followed by experimental validation revealed the following: (1) in addition to transfer-DNA (T-DNA) insertions, three transformed plants carried heritable plasmid backbone DNA of variable sizes (855–5216 bp) and in different configurations with the T-DNA insertions (linked or apart); (2) each transgenic plant contained an estimated 338–1774 independent genetic variations (single nucleotide variations (SNVs) or small insertion/deletions); and (3) 2–6 new Tos17 insertions were detected in each transformed plant, but no other transposable elements or bacterial genomic DNA. PMID:27921404

  12. RESPONSE OF RICE PLANTS TO HEAT STRESS DURING INITIATION OF PANICLE PRIMORDIA OR GRAIN-FILLING PHASES

    OpenAIRE

    2013-01-01

    Leaf photosynthesis, a major determinant for yield sustainability in rice, is greatly conditioned by high temperature stress during growth. The effect of short-term high temperatures on leaf photosynthesis, stomatal conductance, Fv/Fm, SPAD readings and yield characteristics was studied in two Colombian rice cultivars. Two genotypes, cv. Fedearroz 50 (F50) and cv. Fedearroz 733 (F733) were used in pot experiments with heat stress treatment (Plants were exposed to 40°C for two and half hours f...

  13. EXPERIENCE OF USE OF INTEGRATED MARKETING COMMUNICATIONS IN IMPLEMENTATION OF MEANS OF PLANT PROTECTION DURING RICE GROWING

    Directory of Open Access Journals (Sweden)

    Hadzhidi A. P.

    2015-05-01

    Full Text Available The analysis of the development of the Russian market of means of plant protection was made. It was established that the companies-vendor of means of plant protection in Russia have a wide range of output products and extensive application areas. The leaders of the national market of products of plant protection among domestic and foreign manufacturers were identified. The condition of the production and the structure of the Russian market of rice in 2001-2013years were analyzed. The measures of government support provided for rice farmers by "program of state support of agricultural development and market’s regulation of agricultural products, raw materials and food for 2013-2020", were characterized. The analysis of the existing systems of protection of rice showed that the rice farmers have the potential of production to increase yields. Remedies for the seeds protection, controlling diseases (fungicides and pests (insecticides are used very rarely in the system of rice protection. A segmentation of the herbicide market in the Krasnodar region was made. The advantages of the new herbicide called "CITADEL 25" of the Singenta company, the world leader in the market of means of protection of plants, for increasing profitability of cultivation of rice were characterized. The reaction of clients to the price offer of the main herbicides for protection of rice was studied. By results of research the card of values of clients and their preferences was made. The experience of the “Singenta” company in use of the integrated marketing communications for change of values of producers of rice in the Russian Federation is given

  14. Endophytic colonization of rice (Oryza sativa L.) by the diazotrophic bacterium Burkholderia kururiensis and its ability to enhance plant growth

    OpenAIRE

    Mattos, Katherine A; Vania L.M. Pádua; Alexandre Romeiro; Hallack,Leticia F.; Bianca C. Neves; Tecia M.U. Ulisses; Claudia F. Barros; Adriane R Todeschini; Previato, José O.; Lucia Mendonça-Previato

    2008-01-01

    Burkholderia kururiensis is a diazotrophic bacterium originally isolated from a polluted aquifer environment and presents a high level of similarity with the rice endophyte "B. brasilensis" species. This work assessed the ability of B. kururiensis to endophytically colonize rice plantlets by monitoring different tissues of root-inoculated plants for the presence of bacterial growth in different media, electron microscopy and by 16S rDNA analysis. Observations of roots, stems and leaves of ino...

  15. OsPIN5b modulates rice (Oryza sativa) plant architecture and yield by changing auxin homeostasis, transport and distribution.

    Science.gov (United States)

    Lu, Guangwen; Coneva, Viktoriya; Casaretto, José A; Ying, Shan; Mahmood, Kashif; Liu, Fang; Nambara, Eiji; Bi, Yong-Mei; Rothstein, Steven J

    2015-09-01

    Plant architecture attributes such as tillering, plant height and panicle size are important agronomic traits that determine rice (Oryza sativa) productivity. Here, we report that altered auxin content, transport and distribution affect these traits, and hence rice yield. Overexpression of the auxin efflux carrier-like gene OsPIN5b causes pleiotropic effects, mainly reducing plant height, leaf and tiller number, shoot and root biomass, seed-setting rate, panicle length and yield parameters. Conversely, reduced expression of OsPIN5b results in higher tiller number, more vigorous root system, longer panicles and increased yield. We show that OsPIN5b is an endoplasmic reticulum (ER) -localized protein that participates in auxin homeostasis, transport and distribution in vivo. This work describes an example of an auxin-related gene where modulating its expression can simultaneously improve plant architecture and yield potential in rice, and reveals an important effect of hormonal signaling on these traits.

  16. Imidacloprid-induced transference effect on some elements in rice plants and the brown planthopper Nilaparvata lugens (Hemiptera: Delphacidae)

    Institute of Scientific and Technical Information of China (English)

    Samer Azzam; Fan Yang; Jin-Cai Wu; Jin Geng; Guo-Qing Yang

    2011-01-01

    The widespread use of imidacloprid against insect pests has not only increased the rate of the development of target pest resistance but has also resulted in various negative effects on rice plants and Nilaparvata lugens resurgence. However, the effect of imidacloprid on elements in rice plants and the transference of these element changes between rice and N. lugens are currently poorly understood. The present study investigated changes of Cu, Fe, Mn, Zn, Ca, K, Mg and Na contents in rice plants following imidacloprid foliar sprays in the adult female of N. lugens that develops from nymphs that feed on treated plants and honeydew produced by females. The results indicated that imidacloprid foliar spray significantly increased Fe and K contents in leaf sheaths. Generally, Fe, Mn, K and Na contents in leaf blades were noticeably decreased, but Ca contents in leaf blades for 10 and 30 mg/kg imidacloprid treatments were significantly increased. The contents of most elements except K and Mg in the adult females and honeydew were significantly elevated. Multivariate statistical analysis showed that Fe, Mn and Na in leaf blades and Fe and Mn in leaf sheaths could be proportionally transferred to N. lugens. The relationship between most elements in adult female bodies and in the honeydew showed a positive correlation coefficient. There were significant differences in the contents of some elements in rice plants and N. lugens from different regions.

  17. Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling

    Directory of Open Access Journals (Sweden)

    Thiruvengadam Raguchander

    2009-12-01

    Full Text Available Abstract Background Plant Growth Promoting Rhizobacteria (PGPR, Pseudomonas fluorescens strain KH-1 was found to exhibit plant growth promotional activity in rice under both in-vitro and in-vivo conditions. But the mechanism underlying such promotional activity of P. fluorescens is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to P. fluorescens treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry. Results Priming of P. fluorescens, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein. Conclusion Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.

  18. Silicon isotope fractionation between rice plants and nutrient solution and its significance to the study of the silicon cycle

    Science.gov (United States)

    Ding, T. P.; Tian, S. H.; Sun, L.; Wu, L. H.; Zhou, J. X.; Chen, Z. Y.

    2008-12-01

    The silicon isotope fractionation between rice plant and nutrient solution was studied experimentally. Rice plants were grown to maturity with the hydroponic culture in a naturally lit glasshouse. The nutrient solution was sampled for 14 times during the whole rice growth period. The rice plants were collected at various growth stages and different parts of the plants were sampled separately. The silica contents of the samples were determined by the gravimetric method and the silicon isotope compositions were measured using the SiF 4 method. In the growth process, the silicon content in the nutrient solution decreased gradually from 16 mM at starting stage to 0.1-0.2 mM at harvest and the amount of silica in single rice plant increased gradually from 0.00013 g at start to 4.329 g at harvest. Within rice plant the SiO 2 fraction in roots reduced continuously from 0.23 at the seedling stage, through 0.12 at the tiller stage, 0.05 at the jointing stage, 0.023 at the heading stage, to 0.009 at the maturity stage. Accordingly, the fraction of SiO 2 in aerial parts increased from 0.77, through 0.88, 0.95, 0.977, to 0.991 for the same stages. The silicon content in roots decreased from the jointing stage, through the heading stage, to the maturity stage, parallel to the decrease of silicon content in the nutrient solution. At the maturity stage, the silicon content increased from roots, through stem and leaves, to husks, but decreased drastically from husks to grains. These observations show that transpiration and evaporation may play an important role in silica transportation and precipitation within rice plants. It was observed that the δ30Si of the nutrient solution increased gradually from -0.1‰ at start to 1.5‰ at harvest, and the δ30Si of silicon absorbed by bulk rice plant increased gradually from -1.72‰ at start to -0.08‰ at harvest, reflecting the effect of the kinetic silicon isotope fractionation during silicon absorption by rice plants from nutrient

  19. Rice that Filipinos Grow and Eat

    OpenAIRE

    de Leon, John C.

    2005-01-01

    This paper introduces rice to the reader and analyzes the changes it has gone through these past 100 years in the shaping hands of varietal improvement science. Here, the richness of the crop as a genetic material and resource is revealed. Landrace rice, pureline selection rice, crossbred rice, semidwarf rice, hybrid rice, new plant type rice, designer rice - from the traditional to modern to futuristic - rice becomes all of these while traversing time in the Philippines. There is rice for th...

  20. Host plant, distribution and natural enemies of the red date scale insect, Phoenicococcus marlatti (Hemiptera: Phoenicococcidae and its infestation status in Egypt

    Directory of Open Access Journals (Sweden)

    Mona Moustafa

    2012-01-01

    Full Text Available Recently, the red date scale insect, Phoenicococcus marlatti Cockerell (Hemiptera: Phoenicococcidae was recorded as an economic pest of date palm in Egypt. The present work dealt with a survey of host plants, distribution, natural enemies and its infestation status with P. marlatti. The results of the present work indicated that P. marlatti infested Phoenix dactylifera and Washingtonia filifera were found only in 5 governorates in Egypt; Alexandria, Daqahilyia, North Sinai (El-Arish, Giza and Ismailyia. Also, the results indicated that two species of predators were recorded that attacked P. marlatti. These species belong to the Order: Coleoptera, Family Coccinellidae, Pharoscymnus varius (Kirsch and Scymnus punetillum Weise. The results of P. marlatti population dynamics on date palm trees in the first year 2009–2010, indicated that egg density reached its maximum on May 1st, 2010, and its minimum on February 15th, 2010. Preadult density reached its maximum and minimum on May 15th, 2010, and January 15th, respectively, while the highest and lowest adult density were recorded on May 15th, 2010 and January 15th, 2010, respectively. In the second year (2010–2011 egg density reached its maximum and minimum levels on May 1st, 2011 and September 1st, 2010, respectively. Preadult density reached its maximum and minimum on May 15th, 2011 and October 15th, 2010, respectively. Adult density was highest and lowest on May 1st and January 1st, 2011, respectively. The predator recorded in this work in El-Arish region was P. varius. During the first year (2009–2010 no occurrence of predators was noticed from October 15th, 2009 to February 15th, 2010 and the individual population reached its maximum number of 62 individuals per sample. During the second year (2010–2011 no predators were noticed from November 1st, 2010 to February 15th, 2011 and the population reached its maximum number of 58 individuals per sample.

  1. A fluorescent antibiotic resistance marker for rapid production of transgenic rice plants.

    Science.gov (United States)

    Ochiai-Fukuda, Tetsuko; Takahashi-Ando, Naoko; Ohsato, Shuichi; Igawa, Tomoko; Kadokura, Kaori; Hamamoto, Hiroshi; Nakasako, Masayoshi; Kudo, Toshiaki; Shibata, Takehiko; Yamaguchi, Isamu; Kimura, Makoto

    2006-04-20

    Blasticidin S (BS) is an aminoacylnucleoside antibiotic used for the control of rice blast disease. To establish a new cereal transformation system, we constructed a visual marker gene designated gfbsd, encoding an enhanced green fluorescent protein (EGFP) fused to the N-terminus of BS deaminase (BSD). It was cloned into a monocot expression vector and introduced into rice (Oryza sativa L. cv. Nipponbare) calluses by microprojectile bombardment. Three to five weeks after the bombardment, multicellular clusters emitting bright-green EGFP fluorescence were obtained with 10 microg/ml BS, which is not sufficient to completely inhibit the growth of non-transformed tissues. Fluorescent sectors (approximately 2mm in diameter) excised from the calluses regenerated into transgenic plantlets (approximately 10 cm in height) as early as 51 (average 77+/-11) days after the bombardment. The visual antibiotic selection was more efficient and required less time than the bialaphos selection with bar. In addition, the small size (1.1 kb) of gfbsd is preferable for construction of transformation vectors. This new marker gene will make a significant contribution in molecular genetic studies of rice plants.

  2. Aquaporins are major determinants of water use efficiency of rice plants in the field.

    Science.gov (United States)

    Nada, Reham M; Abogadallah, Gaber M

    2014-10-01

    This study aimed at specifying the reasons of unbalanced water relations of rice in the field at midday which results in slowing down photosynthesis and reducing water use efficiency (WUE) in japonica and indica rice under well-watered and droughted conditions. Leaf relative water content (RWC) decreased in the well-watered plants at midday in the field, but more dramatically in the droughted indica (75.6 and 71.4%) than japonica cultivars (85.5 and 80.8%). Gas exchange was measured at three points during the day (9:00, 13:00 and 17:00). Leaf internal CO2 (Ci) was not depleted when midday stomatal depression was highest indicating that Ci was not limiting to photosynthesis. Most aquaporins were predominantly expressed in leaves suggesting higher water permeability in leaves than in roots. The expression of leaf aquaporins was further induced by drought at 9:00 without comparable responses in roots. The data suggest that aquaporin expression in the root endodermis was limiting to water uptake. Upon removal of the radial barriers to water flow in roots, transpiration increased instantly and photosynthesis increased after 4h resulting in increasing WUE after 4h, demonstrating that WUE in rice is largely limited by the inadequate aquaporin expression profiles in roots.

  3. Increasing nitrogen rates in rice and its effect on plant nutrient composition and nitrogen apparent recovery

    Directory of Open Access Journals (Sweden)

    Juan Hirzel

    2013-12-01

    Full Text Available Rice (Oryza sativa L. is one of the essential foods of the human diet; advances in agronomic crop management can improve productivity and profitability as well as reduce adverse environmental impacts. Nitrogen rates in Chile are generally based on crop yield without considering other agronomic factors. The objective of this experiment was to determine the effect of increasing N rates on plant nutrient composition and N apparent recovery in rice cultivated in five different locations in Chile. The five sites located in central Chile belong to one of the following soil orders: Inceptisol, Alfisol, and Vertisol; they were cropped in field conditions with 'Zafiro-INIA' rice fertilized with 0, 80, and 160 kg N ha-1. Whole-plant total DM, macronutrient composition, and N apparent recovery efficiency (NARE were determined at grain harvest. Results indicate that all evaluated parameters, with the exception of K concentration, were affected by the soil used. Nitrogen rates only affected total DM production and P, K, and Mg concentrations in plants. Phosphorus and K response decreased when N was added to some soils, which is associated with its chemical properties. Magnesium concentration exhibited an erratic effect, but it was not affected by the N rate in most soils. Nitrogen apparent recovery efficiency was not affected by the N rate and accounted for approximately 49% and 41% for 80 and 160 kg N ha-1, respectively. Macronutrient composition was 5.1-7.7 g N, 1.3-1.8 g P, 5.4-10.8 g K, 1.68-2.57 g Ca, and 0.81-1.45 g Mg kg-1 of total DM.

  4. Members of rice plasma membrane intrinsic proteins subfamily are involved in arsenite permeability and tolerance in plants.

    Science.gov (United States)

    Mosa, Kareem A; Kumar, Kundan; Chhikara, Sudesh; Mcdermott, Joseph; Liu, Zijuan; Musante, Craig; White, Jason C; Dhankher, Om Parkash

    2012-12-01

    Rice accumulates high level of arsenic (As) in its edible parts and thus plays an important role in the transfer of As into the food chain. However, the mechanisms of As uptake and its detoxification in rice are not well understood. Recently, members of the Nodulin 26-like intrinsic protein (NIP) subfamily of plant aquaporins were shown to transport arsenite in rice and Arabidopsis. Here we report that members of the rice plasma membrane intrinsic protein (PIP) subfamily are also involved in As tolerance and transport. Based on the homology search with the mammalian AQP9 and yeast Fps1 arsenite transporters, we identified and cloned five rice PIP gene subfamily members. qRT-PCR analysis of PIPs in rice root and shoot tissues revealed a significant down regulation of transcripts encoding OsPIP1;2, OsPIP1;3, OsPIP2;4, OsPIP2;6, and OsPIP2;7 in response to arsenite treatment. Heterologous expression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Xenopus laevis oocytes significantly increased the uptake of arsenite. Overexpression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Arabidopsis yielded enhanced arsenite tolerance and higher biomass accumulation. Further, these transgenic plants showed no significant accumulation of As in shoot and root tissues in long term uptake assays. Whereas, short duration exposure to arsenite caused both active influx and efflux of As in the roots. The data suggests a bidirectional arsenite permeability of rice PIPs in plants. These rice PIPs genes will be highly useful for engineering important food and biofuel crops for enhanced crop productivity on contaminated soils without increasing the accumulation of toxic As in the biomass or edible tissues.

  5. Disruption of OsYSL15 leads to iron inefficiency in rice plants.

    Science.gov (United States)

    Lee, Sichul; Chiecko, Jeff C; Kim, Sun A; Walker, Elsbeth L; Lee, Youngsook; Guerinot, Mary Lou; An, Gynheung

    2009-06-01

    Uptake and translocation of metal nutrients are essential processes for plant growth. Graminaceous species release phytosiderophores that bind to Fe(3+); these complexes are then transported across the plasma membrane. We have characterized OsYSL15, one of the rice (Oryza sativa) YS1-like (YSL) genes that are strongly induced by iron (Fe) deficiency. The OsYSL15 promoter fusion to beta-glucuronidase showed that it was expressed in all root tissues when Fe was limited. In low-Fe leaves, the promoter became active in all tissues except epidermal cells. This activity was also detected in flowers and seeds. The OsYSL15:green fluorescent protein fusion was localized to the plasma membrane. OsYSL15 functionally complemented yeast strains defective in Fe uptake on media containing Fe(3+)-deoxymugineic acid and Fe(2+)-nicotianamine. Two insertional osysl15 mutants exhibited chlorotic phenotypes under Fe deficiency and had reduced Fe concentrations in their shoots, roots, and seeds. Nitric oxide treatment reversed this chlorosis under Fe-limiting conditions. Overexpression of OsYSL15 increased the Fe concentration in leaves and seeds from transgenic plants. Altogether, these results demonstrate roles for OsYSL15 in Fe uptake and distribution in rice plants.

  6. Multitemporal Monitoring of Plant Area Index in the Valencia Rice District with PocketLAI

    Directory of Open Access Journals (Sweden)

    Manuel Campos-Taberner

    2016-03-01

    Full Text Available Leaf area index (LAI is a key biophysical parameter used to determine foliage cover and crop growth in environmental studies in order to assess crop yield. Frequently, plant canopy analyzers (LAI-2000 and digital cameras for hemispherical photography (DHP are used for indirect effective plant area index (PAIeff estimates. Nevertheless, these instruments are expensive and have the disadvantages of low portability and maintenance. Recently, a smartphone app called PocketLAI was presented and tested for acquiring PAIeff measurements. It was used during an entire rice season for indirect PAIeff estimations and for deriving reference high-resolution PAIeff maps. Ground PAIeff values acquired with PocketLAI, LAI-2000, and DHP were well correlated (R2 = 0.95, RMSE = 0.21 m2/m2 for Licor-2000, and R2 = 0.94, RMSE = 0.6 m2/m2 for DHP. Complementary data such as phenology and leaf chlorophyll content were acquired to complement seasonal rice plant information provided by PAIeff. High-resolution PAIeff maps, which can be used for the validation of remote sensing products, have been derived using a global transfer function (TF made of several measuring dates and their associated satellite radiances.

  7. Transferability of Models for Estimating Paddy Rice Biomass from Spatial Plant Height Data

    Directory of Open Access Journals (Sweden)

    Nora Tilly

    2015-07-01

    Full Text Available It is known that plant height is a suitable parameter for estimating crop biomass. The aim of this study was to confirm the validity of spatial plant height data, which is derived from terrestrial laser scanning (TLS, as a non-destructive estimator for biomass of paddy rice on the field scale. Beyond that, the spatial and temporal transferability of established biomass regression models were investigated to prove the robustness of the method and evaluate the suitability of linear and exponential functions. In each growing season of two years, three campaigns were carried out on a field experiment and on a farmer’s conventionally managed field. Crop surface models (CSMs were generated from the TLS-derived point clouds for calculating plant height with a very high spatial resolution of 1 cm. High coefficients of determination between CSM-derived and manually measured plant heights (R2: 0.72 to 0.91 confirm the applicability of the approach. Yearly averaged differences between the measurements were ~7% and ~9%. Biomass regression models were established from the field experiment data sets, based on strong coefficients of determination between plant height and dry biomass (R2: 0.66 to 0.86 and 0.65 to 0.84 for linear and exponential models, respectively. The spatial and temporal transferability of the models to the farmer’s conventionally managed fields is supported by strong coefficients of determination between estimated and measured values (R2: 0.60 to 0.90 and 0.56 to 0.85 for linear and exponential models, respectively. Hence, the suitability of TLS-derived spatial plant height as a non-destructive estimator for biomass of paddy rice on the field scale was verified and the transferability demonstrated.

  8. QTLs for heading date and plant height under multiple environments in rice.

    Science.gov (United States)

    Han, Zhongmin; Hu, Wei; Tan, Cong; Xing, Yongzhong

    2017-02-01

    Both heading date and plant height are important traits related to grain yield in rice. In this study, a recombinant inbred lines (RILs) population was used to map quantitative trait loci (QTLs) for both traits under 3 long-day (LD) environments and 1 short-day (SD) environment. A total of eight QTLs for heading date and three QTLs for plant height were detected by composite interval mapping under LD conditions. Additional one QTL for heading date and three QTLs for plant height were identified by Two-QTL model under LD conditions. Among them, major QTLs qHd7.1, qHd7.2 and qHd8 for heading date, and qPh1 and qPh7.1 for plant height were commonly detected. qHd7.1 and qHd7.2 were mapped to small regions of less than 1 cM. Genome position comparison of previously cloned genes with QTLs detected in this study revealed that qHd5 and qPh3.1 were two novel QTLs. The alleles of these QTLs increasing trait values were dispersed in both parents, which well explained the transgressive segregation observed in this population. In addition, the interaction between qHd7.1 and qHd8 was detected under all LD conditions. Multiple-QTL model analysis revealed that all QTLs and their interactions explained over 80% of heading date variation and 50% of plant height variation. Two heading date QTLs were detected under SD condition. Of them, qHd10 were commonly identified under LD condition. The difference in QTL detection between LD and SD conditions indicated most heading date QTLs are sensitive to photoperiod. These findings will benefit breeding design for heading date and plant height in rice.

  9. Características de plantas de cultivares de arroz irrigado relacionadas à habilidade competitiva com plantas concorrentes Characteristics of flooded rice cultivar plants related to competitive ability against weeds concurrent plants

    Directory of Open Access Journals (Sweden)

    N.G. Fleck

    2003-04-01

    Full Text Available Plantas que apresentam rápido crescimento tendem a ocupar precocemente nichos disponíveis, utilizando o espaço de suas vizinhas. Em geral, esses vegetais adquirem prioridade na utilização dos recursos do meio. O objetivo deste trabalho foi avaliar variações em características de crescimento de cultivares de arroz irrigado. Para isso, conduziu-se um experimento em campo na estação de crescimento de 2000/2001, em Cachoeirinha-RS. Investigou-se o comportamento de oito cultivares de arroz, cultivados em presença e ausência de plantas de arroz do cultivar EEA 406, simulando infestação de arroz-vermelho, estabelecida com densidade média de 30 plantas m-2. Entre 15 e 60 dias após a semeadura (DAS, avaliou-se a evolução de área foliar, estatura e massa aérea das plantas de arroz. Com esses dados, calcularam-se razão de área foliar (RAF, taxa de crescimento relativo (TCR e taxa de assimilação líquida (TAL dos cultivares. Os cultivares Ligeirinho e XL 6 apresentaram elevadas velocidades de ganho em área foliar, estatura e massa aérea; com isso, alcançaram as maiores coberturas do solo, juntamente com o cultivar IR 841. Por outro lado, os cultivares Bluebelle e Formosa mostraram lento crescimento absoluto no período avaliado, mas, em geral, apresentaram os maiores valores para TCR e TAL.Fast-growing plants tend to occupy available niches utilizing these spaces ahead of their neighbors. In general, these plants have priority over others in the use of environmental resources. The objective of this research was to evaluate variations in growth characteristics of flooded rice cultivars. A field experiment was carried out during the 2000/01 summer season, in Cachoeirinha, RS, Brazil. The behavior of eight rice cultivars, grown in the absence or presence of the EEA 406 rice genotype was investigated, simulating a red rice infestation, established at an average density of 30 plants m-2. From 15 to 60 days after seeding (DAS

  10. Mutualistic fungal endophytes produce phytohormones and organic acids that promote japonica rice plant growth under prolonged heat stress.

    Science.gov (United States)

    Waqas, Muhammad; Khan, Abdul Latif; Shahzad, Raheem; Ullah, Ihsan; Khan, Abdur Rahim; Lee, In-Jung

    2015-12-01

    This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The japonica rice was grown in controlled chamber conditions with and without P. formosus LWL1 under no stress (NS) and prolonged heat stress (HS) conditions. Endophytic association under NS and HS conditions significantly improved plant growth attributes, such as plant height, fresh weight, dry weight, and chlorophyll content. Furthermore, P. formosus LWL1 protected the rice plants from HS compared with controls, indicated by the lower endogenous level of stress-signaling compounds such as abscisic acid (25.71%) and jasmonic acid (34.57%) and the increase in total protein content (18.76%-33.22%). Such fungal endophytes may be helpful for sustainable crop production under high environmental temperatures.

  11. Traditional and modern plant breeding methods with examples in rice (Oryza sativa L.).

    Science.gov (United States)

    Breseghello, Flavio; Coelho, Alexandre Siqueira Guedes

    2013-09-01

    Plant breeding can be broadly defined as alterations caused in plants as a result of their use by humans, ranging from unintentional changes resulting from the advent of agriculture to the application of molecular tools for precision breeding. The vast diversity of breeding methods can be simplified into three categories: (i) plant breeding based on observed variation by selection of plants based on natural variants appearing in nature or within traditional varieties; (ii) plant breeding based on controlled mating by selection of plants presenting recombination of desirable genes from different parents; and (iii) plant breeding based on monitored recombination by selection of specific genes or marker profiles, using molecular tools for tracking within-genome variation. The continuous application of traditional breeding methods in a given species could lead to the narrowing of the gene pool from which cultivars are drawn, rendering crops vulnerable to biotic and abiotic stresses and hampering future progress. Several methods have been devised for introducing exotic variation into elite germplasm without undesirable effects. Cases in rice are given to illustrate the potential and limitations of different breeding approaches.

  12. Constitutive expression of a plant ferredoxin-like protein (pflp) enhances capacity of photosynthetic carbon assimilation in rice (Oryza sativa).

    Science.gov (United States)

    Chang, Hsiang; Huang, Hsiang-En; Cheng, Chin-Fu; Ho, Mei-Hsuan; Ger, Mang-Jye

    2017-04-01

    The plant ferredoxin-like protein (PFLP) gene, cloned from sweet peppers predicted as an electron carrier in photosynthesis, shows high homology to the Fd-I sequence of Arabidopsis thaliana, Lycopersicon esculentum, Oryza sativa and Spinacia oleracea. Most of pflp related studies focused on anti-pathogenic effects, while less understanding for the effects in photosynthesis with physiological aspects, such as photosynthesis rate, and levels of carbohydrate metabolites. This project focuses on the effects of pflp overexpression on photosynthesis by physiological evaluations of carbon assimilation with significant higher levels of carbohydrates with higher photosynthesis efficiency. In this report, two independent transgenic lines of rice plants (designated as pflp-1 and pflp-2) were generated from non-transgenic TNG67 rice plant (WT). Both transgenic pflp rice plants exhibited enhanced photosynthesis efficiency, and gas exchange rates of photosynthesis were 1.3- and 1.2-fold higher for pflp-1 and pflp-2 than WT respectively. Significantly higher electron transport rates of pflp rice plants were observed. Moreover, photosynthetic products, such as fructose, glucose, sucrose and starch contents of pflp transgenic lines were increased accordingly. Molecular evidences of carbohydrate metabolism related genes activities (osHXK5, osHXK6, osAGPL3, osAGPS2α, osSPS, ospFBPase, oscFBPase, and osSBPase) in transgenic lines were higher than those of WT. For performance of crop production, 1000-grain weight for pflp-1 and pflp-2 rice plants were 52.9 and 41.1 g that were both significantly higher than 31.6 g for WT, and panicles weights were 1.4- and 1.2-fold higher than WT. Panicle number, tiller number per plants for pflp rice plants were all significantly higher compared with those of WT where there was no significant difference observed between two pflp rice plants. Taken altogether; this study demonstrated that constitutive pflp expression can improve rice production by

  13. Relationship between xanthophyll cycle and non-photochemical quenching in rice (Oryza sativa L.) plants in response to light stress.

    Science.gov (United States)

    Vaz, Janet; Sharma, Prabhat K

    2011-01-01

    Thirty days old rice plants grown under low and moderate light conditions were transferred to full sunlight to observe the extent of photoinhibitory damage and protective mechanism, and the relationship between xanthophyll cycle and nonphotochemical quenching (qN) under changing light environment. Control plants (low, moderate and sun grown) exhibited similar Fv/Fm ratio, indicating similar photosynthetic efficiency prior to light stress. On exposure to the high light treatment, low light grown plants exhibited faster and higher degree of photoinhibition compared to moderate and high light grown plants. Moderate and high light grown plants showed relatively less photoinhibition and also showed higher qN, indicating better capacity of energy dissipation. Increase in qN in moderate light and sun grown plants was accompanied by conversion of violaxanthin (V) to antheraxanthin (A) and zeaxanthin (Z) indicating operation of Z-dependent thermal dissipation. Rice plants fed with ascorbate (AsA), a stimulator of the de-epoxidation state of V to Z, showed higher Fv/Fm ratio and qN than the plants fed with dithiothreitol (DTT) an inhibitor of xanthophyll cycle. This indicated that an increased amount of energy reached PS II reaction centre, due to absence of A and Z formation, thereby causing greater damage to photosynthesis in DTT fed rice plants. The present data confirmed the relationship between qN and Z in dissipating the excess light energy, thereby protecting plants against photodamage.

  14. Short-term effects of compost amendment on the fractionation of cadmium in soil and cadmium accumulation in rice plants.

    Science.gov (United States)

    Juang, Kai-Wei; Ho, Pei-Chi; Yu, Chun-Hui

    2012-06-01

    We used a sequential extraction to investigate the effects of compost amendment on Cd fractionation in soil during different incubation periods in order to assess Cd stabilization in soil over time. Pot experiments using rice plants growing on Cd-spiked soils were carried out to evaluate the influence of compost amendment on plant growth and Cd accumulation by rice. Two agricultural soils (Pinchen and Lukang) of Taiwan were used for the experiments. The relationship between the redistribution of Cd fractions and the reduction of plant Cd concentration due to compost amendment was then investigated. Compost amendment in Pinchen soil (lower pH) could transform exchangeable Cd into the Fe- and Mn-oxide-bound forms. With increasing incubation time, exchangeable Cd tended to transform into carbonate- and Fe- and Mn-oxide-bound fractions. In Lukang soil (higher pH), carbonate- and Fe- and Mn-oxide-bonded Cd were the main fractions. Exchangeable Cd was low. Compost amendment transformed the carbonate-bound form into the Fe and Mn oxide form. Pot experiments of rice plants showed that compost amendment enhanced plant growth more in Pinchen soil than in Lukang soil. Compost amendment could significantly reduce Cd accumulation in rice roots in both Pinchen and Lukang soils and restrict internal transport of Cd from the roots to the shoots. Because exchangeable Cd can be transformed into the stronger bonded fractions quickly in Pinchen soil, a reduction of Cd accumulation in rice due to compost amendment of Pinchen soil was significant by 45 days of growth. However, carbonate-bonded fractions in Lukang soil may provide a source of available Cd to rice plants, and exchangeable and carbonate-bonded fractions are transformed into the other fractions slowly. Thus, reduction of Cd accumulation by rice due to compost amendment in Lukang soil was significant by 75 days of growth. The results of the study suggest that the effectiveness of compost amendment used for stabilization of

  15. Polycomb Protein OsFIE2 Affects Plant Height and Grain Yield in Rice

    Science.gov (United States)

    Sheng, Zhonghua; Jiao, Guiai; Tang, Shaoqing; Luo, Ju; Hu, Peisong

    2016-01-01

    Polycomb group (PcG) proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2) protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice. PMID:27764161

  16. Essential oils of indigenous plants protect livestock from infestations of Rhipicephalus appendiculatus and other tick species in herds grazing in natural pastures in western Kenya

    NARCIS (Netherlands)

    Wanzala, Wycliffe; Hassanali, Ahmed; Mukabana, Wolfgang Richard; Takken, Willem

    2017-01-01

    The effects of formulated essential oils of Tagetes minuta and Tithonia diversifolia on Rhipicephalus appendiculatus infesting livestock were evaluated in semi-field experiments. Forty-five zebu cattle naturally infested with ticks were randomly selected from 15 herds, three animals from each. Of

  17. Biocontrol and plant growth promoting activities of a Streptomyces corchorusii strain UCR3-16 and preparation of powder formulation for application as biofertilizer agents for rice plant.

    Science.gov (United States)

    Tamreihao, K; Ningthoujam, Debananda S; Nimaichand, Salam; Singh, Elangbam Shanta; Reena, Pascal; Singh, Salam Herojeet; Nongthomba, Upendra

    2016-11-01

    Streptomyces corchorusii strain UCR3-16, obtained from rice rhizospheric soils showed antifungal activities against 6 major rice fungal pathogens by diffusible and volatile compounds production. The strain was found positive for production of fungal cell wall degrading enzymes such as chitinase, β-1,3-glucanase, β-1,4-glucanase, lipase and protease. The strain was also positive for plant growth promoting traits. It produced up to 30.5μg/ml of IAA and solubilized a significant amount of inorganic phosphate (up to 102μg/ml). It also produced 69% siderophore units. The strain also produced ammonia and gave positive result for ACC deaminase activity. Highest vigor index of inoculated seedlings was observed when rice seeds were treated with cell suspension of UCR3-16 corresponding to 4.5×10(8)cfu/ml. Bioinoculant-treated seeds also showed similar results under pathogen challenged conditions. In pot trial experiments, UCR3-16-treated rice plants showed significantly increased growth and grain yield production. Powder formulation of the strain was developed using talcum and corn starch as carriers and the shelf-lives were monitored. Talcum formulation showed higher cell-count than corn starch even after 6 months of storage, and optimum condition for storage of the powder formulation were found to be at 4°C. Pot trial experiments using talcum powder formulation also showed significant positive effects on growth of rice plants. Field trial using talcum powder formulation also exhibited significant enhancement in shoot length and weight of shoot and root, and total grain yield and weight of grains in rice plants. Talcum formulation also significantly reduced the sheath blight disease in rice leaves. Copyright © 2016. Published by Elsevier GmbH.

  18. The availabilities of arsenic and cadmium in rice paddy fields from a mining area: The role of soil extractable and plant silicon.

    Science.gov (United States)

    Yu, Huan-Yun; Ding, Xiaodong; Li, Fangbai; Wang, Xiangqin; Zhang, Shirong; Yi, Jicai; Liu, Chuanping; Xu, Xianghua; Wang, Qi

    2016-08-01

    Adequate silicon (Si) can greatly boost rice yield and improve grain quality through alleviating stresses associated with heavy metals and metalloids such as arsenic (As) and cadmium (Cd). The soil plant-available Si is relatively low in South China due to severe desilicification and allitization of the soils in this region. Conversely, pollution of heavy metals and metalloids in the soils of this region occurs widely, especially As and Cd pollution in paddy soil. Therefore, evaluating the plant availability of Si in paddy soil of South China and examining its correlation with the availability of heavy metals and metalloids are of great significance. Accordingly, in our study, 107 pairs of soil and rice plant samples were collected from paddy fields contaminated by As and Cd in South China. Significantly positive correlations between Si in rice plants and Si fractions in soils extracted with citric acid, NaOAc-HOAc buffer, and oxalate-ammonium oxalate buffer suggest that these extractants are more suitable for use in extracting plant-available Si in the soils of our present study. Significantly negative correlations between different Si fractions and As or Cd in rice plant tissues and negative exponential correlations between the molar ratios of Si to As/Cd in rice roots, straws, husks or grains and As/Cd in rice grains indicate that Si can significantly alleviate the accumulation of As/Cd from soils to the rice plants. Finally, a contribution assessment of soil properties to As/Cd accumulation in rice grains based on random forest showed that in addition to Si concentrations in soil or rice plants, other factors such as Fe fractions and total phosphorus also contributed largely to As/Cd accumulation in rice grains. Overall, Si exhibited its unique role in mitigating As or Cd stress in rice, and our study results provide strong field evidence for this role.

  19. Characteristics of photosynthesis in rice plants transformed with an antisense Rubisco activase gene

    Institute of Scientific and Technical Information of China (English)

    金松恒; 蒋德安; 李雪芹; 孙骏威

    2004-01-01

    Transgenic rice plants with an antisense gene inserted via Agrobacterium tumefaciens were used to explore the impact of the reduction of Rubisco activase (RCA) on Rubisco and photosynthesis. In this study, transformants containing 15% to 35% wild type Rubisco activase were selected, which could survive in ambient CO2 concentration but grew slowly compared with wild type controls. Gas exchange measurements indicated that the rate of photosynthesis decreased sig-nificantly, while stomatal conductance and transpiration rate did not change; and that the intercellular CO2 concentration even increased. Rubisco determination showed that these plants had approximately twice as much Rubisco as the wild types,although they showed 70% lower rate of photosynthesis, whichRubsico activase and/or the reduction in carbamylation.was likely an acclimation response to the reduction in Rubsico activase and/or the reduction in carbamylation.

  20. Characteristics of photosynthesis in rice plants transformed with an antisense Rubisco activase gene

    Institute of Scientific and Technical Information of China (English)

    金松恒; 蒋德安; 李雪芹; 孙骏威

    2004-01-01

    Transgenic rice plants with an antisense gene inserted via Agrobacterium tumefaciens were used to explore the impact of the reduction of Rubisco activase (RCA) on Rubisco and photosynthesis. In this study, transformants containing 15% to 35% wild type Rubisco activase were selected, which could survive in ambient CO2 concentration but grew slowly compared with wild type controls. Gas exchange measurements indicated that the rate of photosynthesis decreased significantly, while stomatal conductance and transpiration rate did not change; and that the intercellular CO2 concentration even increased. Rubisco determination showed that these plants had approximately twice as much Rubisco as the wild types,although they showed 70% lower rate of photosynthesis, which was likely an acclimation response to the reduction inRubsico activase and/or the reduction in carbamylation.

  1. Characteristics of photosynthesis in rice plants transformed with an antisense Rubisco activase gene.

    Science.gov (United States)

    Jin, Song-Heng; Jiang, De-An; Li, Xue-Qin; Sun, Jun-Wei

    2004-08-01

    Transgenic rice plants with an antisense gene inserted via Agrobacterium tumefaciens were used to explore the impact of the reduction of Rubisco activase (RCA) on Rubisco and photosynthesis. In this study, transformants containing 15% to 35% wild type Rubisco activase were selected, which could survive in ambient CO2 concentration but grew slowly compared with wild type controls. Gas exchange measurements indicated that the rate of photosynthesis decreased significantly, while stomatal conductance and transpiration rate did not change; and that the intercellular CO2 concentration even increased. Rubisco determination showed that these plants had approximately twice as much Rubisco as the wild types, although they showed 70% lower rate of photosynthesis, which was likely an acclimation response to the reduction in Rubsico activase and/or the reduction in carbamylation.

  2. Ethylene participates in the regulation of Fe deficiency responses in Strategy I plants and in rice

    Directory of Open Access Journals (Sweden)

    Carlos eLucena

    2015-11-01

    Full Text Available Iron (Fe is very abundant in most soils but its availability for plants is low, especially in calcareous soils. Plants have been divided into Strategy I and Strategy II species to acquire Fe from soils. Strategy I species apply a reduction-based uptake system which includes all higher plants except the Poaceae. Strategy II species apply a chelation-based uptake system which includes the Poaceae. To cope with Fe deficiency both type of species activate several Fe deficiency responses, mainly in their roots. These responses need to be tightly regulated to avoid Fe toxicity and to conserve energy. Their regulation is not totally understood but some hormones and signaling substances have been implicated. Several years ago it was suggested that ethylene could participate in the regulation of Fe deficiency responses in Strategy I species. In Strategy II species, the role of hormones and signaling substances has been less studied. However, in rice, traditionally considered a Strategy II species but that possesses some characteristics of Strategy I species, it has been recently shown that ethylene can also play a role in the regulation of some of its Fe deficiency responses. Here, we will review and discuss the data supporting a role for ethylene in the regulation of Fe deficiency responses in both Strategy I species and rice. In addition, we will review the data about ethylene and Fe responses related to Strategy II species. We will also discuss the results supporting the action of ethylene through different transduction pathways and its interaction with other signals, such as certain Fe-related repressive signals occurring in the phloem sap. Finally, the possible implication of ethylene in the interactions among Fe deficiency responses and the responses to other nutrient deficiencies in the plant will be addressed.

  3. Increased fitness of rice plants to abiotic stress via habitat adapted symbiosis: A strategy for mitigating impacts of climate change

    Science.gov (United States)

    Redman, R.S.; Kim, Y.-O.; Woodward, C.J.D.A.; Greer, C.; Espino, L.; Doty, S.L.; Rodriguez, R.J.

    2011-01-01

    Climate change and catastrophic events have contributed to rice shortages in several regions due to decreased water availability and soil salinization. Although not adapted to salt or drought stress, two commercial rice varieties achieved tolerance to these stresses by colonizing them with Class 2 fungal endophytes isolated from plants growing across moisture and salinity gradients. Plant growth and development, water usage, ROS sensitivity and osmolytes were measured with and without stress under controlled conditions. The endophytes conferred salt, drought and cold tolerance to growth chamber and greenhouse grown plants. Endophytes reduced water consumption by 20–30% and increased growth rate, reproductive yield, and biomass of greenhouse grown plants. In the absence of stress, there was no apparent cost of the endophytes to plants, however, endophyte colonization decreased from 100% at planting to 65% compared to greenhouse plants grown under continual stress (maintained 100% colonization). These findings indicate that rice plants can exhibit enhanced stress tolerance via symbiosis with Class 2 endophytes, and suggest that symbiotic technology may be useful in mitigating impacts of climate change on other crops and expanding agricultural production onto marginal lands.

  4. Increased fitness of rice plants to abiotic stress via habitat adapted symbiosis: a strategy for mitigating impacts of climate change.

    Science.gov (United States)

    Redman, Regina S; Kim, Yong Ok; Woodward, Claire J D A; Greer, Chris; Espino, Luis; Doty, Sharon L; Rodriguez, Rusty J

    2011-01-01

    Climate change and catastrophic events have contributed to rice shortages in several regions due to decreased water availability and soil salinization. Although not adapted to salt or drought stress, two commercial rice varieties achieved tolerance to these stresses by colonizing them with Class 2 fungal endophytes isolated from plants growing across moisture and salinity gradients.Plant growth and development, water usage, ROS sensitivity and osmolytes were measured with and without stress under controlled conditions.The endophytes conferred salt, drought and cold tolerance to growth chamber and greenhouse grown plants. Endophytes reduced water consumption by 20-30% and increased growth rate, reproductive yield, and biomass of greenhouse grown plants. In the absence of stress, there was no apparent cost of the endophytes to plants, however, endophyte colonization decreased from 100% at planting to 65% compared to greenhouse plants grown under continual stress (maintained 100% colonization).These findings indicate that rice plants can exhibit enhanced stress tolerance via symbiosis with Class 2 endophytes, and suggest that symbiotic technology may be useful in mitigating impacts of climate change on other crops and expanding agricultural production onto marginal lands.

  5. Increased fitness of rice plants to abiotic stress via habitat adapted symbiosis: a strategy for mitigating impacts of climate change.

    Directory of Open Access Journals (Sweden)

    Regina S Redman

    Full Text Available Climate change and catastrophic events have contributed to rice shortages in several regions due to decreased water availability and soil salinization. Although not adapted to salt or drought stress, two commercial rice varieties achieved tolerance to these stresses by colonizing them with Class 2 fungal endophytes isolated from plants growing across moisture and salinity gradients.Plant growth and development, water usage, ROS sensitivity and osmolytes were measured with and without stress under controlled conditions.The endophytes conferred salt, drought and cold tolerance to growth chamber and greenhouse grown plants. Endophytes reduced water consumption by 20-30% and increased growth rate, reproductive yield, and biomass of greenhouse grown plants. In the absence of stress, there was no apparent cost of the endophytes to plants, however, endophyte colonization decreased from 100% at planting to 65% compared to greenhouse plants grown under continual stress (maintained 100% colonization.These findings indicate that rice plants can exhibit enhanced stress tolerance via symbiosis with Class 2 endophytes, and suggest that symbiotic technology may be useful in mitigating impacts of climate change on other crops and expanding agricultural production onto marginal lands.

  6. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice

    Institute of Scientific and Technical Information of China (English)

    Deyong Ren; Li Zhu; Zhenyu Gao; Guojun Dong; Guangheng Zhang; Longbiao Guo; Dali Zeng; and Qian Qian; Yuchun Rao; Liwen Wu; Qiankun Xu; Zizhuang Li; Haiping Yu; Yu Zhang; Yujia Leng; Jiang Hu

    2016-01-01

    Moderate plant height and successful establish-ment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull-like lodicules. AFD1 encoded a DUF640 domain protein and was ex-pressed in all tested tissues and organs. Subcellular localization showed AFD1-green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes.

  7. Exergetic analysis of a steam power plant using coal and rice straw in a co-firing process

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, Alvaro; Miyake, Raphael Guardini; Bazzo, Edson [Federal University of Santa Catarina (UFSC), Dept. of Mechanical Engineering, Florianopolis, SC (Brazil)], e-mails: arestrep@labcet.ufsc.br, miyake@labcet.ufsc.br, ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Capivari de Baixo, SC (Brazil). U.O. Usina Termeletrica Jorge Lacerda C.], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    This paper presents an exergetic analysis concerning an existing 50 M We steam power plant, which operates with pulverized coal from Santa Catarina- Brazil. In this power plant, a co-firing rice straw is proposed, replacing up to 10% of the pulverized coal in energy basis required for the boiler. Rice straw has been widely regarded as an important source for bio-ethanol, animal feedstock and organic chemicals. The use of rice straw as energy source for electricity generation in a co-firing process with low rank coal represents a new application as well as a new challenge to overcome. Considering both scenarios, the change in the second law efficiency, exergy destruction, influence of the auxiliary equipment and the greenhouse gases emissions such as CO{sub 2} and SO{sub 2} were considered for analysis. (author)

  8. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice

    Science.gov (United States)

    Ren, Deyong; Rao, Yuchun; Wu, Liwen; Xu, Qiankun; Li, Zizhuang; Yu, Haiping; Zhang, Yu; Leng, Yujia; Hu, Jiang; Zhu, Li; Gao, Zhenyu; Dong, Guojun; Zhang, Guangheng; Guo, Longbiao

    2016-01-01

    Abstract Moderate plant height and successful establishment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull‐like lodicules. AFD1 encoded a DUF640 domain protein and was expressed in all tested tissues and organs. Subcellular localization showed AFD1‐green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes. PMID:26486996

  9. Aboveground insect infestation attenuates belowground Agrobacterium-mediated genetic transformation.

    Science.gov (United States)

    Song, Geun Cheol; Lee, Soohyun; Hong, Jaehwa; Choi, Hye Kyung; Hong, Gun Hyong; Bae, Dong-Won; Mysore, Kirankumar S; Park, Yong-Soon; Ryu, Choong-Min

    2015-07-01

    Agrobacterium tumefaciens causes crown gall disease. Although Agrobacterium can be popularly used for genetic engineering, the influence of aboveground insect infestation on Agrobacterium induced gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect (whitefly) infestation and benzothiadiazole (BTH) for 7 d, and these exposed plants were inoculated with a tumorigenic Agrobacterium strain. We evaluated, both in planta and in vitro, how whitefly infestation affects crown gall disease. Whitefly-infested plants exhibited at least a two-fold reduction in gall formation on both stem and crown root. Silencing of isochorismate synthase 1 (ICS1), required for salicylic acid (SA) synthesis, compromised gall formation indicating an involvement of SA in whitefly-derived plant defence against Agrobacterium. Endogenous SA content was augmented in whitefly-infested plants upon Agrobacterium inoculation. In addition, SA concentration was three times higher in root exudates from whitefly-infested plants. As a consequence, Agrobacterium-mediated transformation of roots of whitefly-infested plants was clearly inhibited when compared to control plants. These results suggest that aboveground whitefly infestation elicits systemic defence responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand interactions between three organisms: whitefly, N. benthamiana and Agrobacterium. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  10. Expression of the maize proteinase inhibitor (mpi) gene in rice plants enhances resistance against the striped stem borer (Chilo suppressalis): effects on larval growth and insect gut proteinases.

    Science.gov (United States)

    Vila, Laura; Quilis, Jordi; Meynard, Donaldo; Breitler, Jean Christophe; Marfà, Victoria; Murillo, Isabel; Vassal, Jean Michel; Messeguer, Joaquima; Guiderdoni, Emmanuel; San Segundo, Blanca

    2005-03-01

    The maize proteinase inhibitor (mpi) gene was introduced into two elite japonica rice varieties. Both constitutive expression of the mpi gene driven by the maize ubiquitin 1 promoter and wound-inducible expression of the mpi gene driven by its own promoter resulted in the accumulation of MPI protein in the transgenic plants. No effect on plant phenotype was observed in mpi-expressing lines. The stability of transgene expression through successive generations of mpi rice lines (up to the T(4) generation) and the production of functional MPI protein were confirmed. Expression of the mpi gene in rice enhanced resistance to the striped stem borer (Chilo suppressalis), one of the most important pests of rice. In addition, transgenic mpi plants were evaluated in terms of their effects on the growth of C. suppressalis larvae and the insect digestive proteolytic system. An important dose-dependent reduction of larval weight of C. suppressalis larvae fed on mpi rice, compared with larvae fed on untransformed rice plants, was observed. Analysis of the digestive proteolytic activity from the gut of C. suppressalis demonstrated that larvae adapted to mpi transgene expression by increasing the complement of digestive proteolytic activity: the serine and cysteine endoproteinases as well as the exopeptidases leucine aminopeptidase and carboxypeptidases A and B. However, the induction of such proteolytic activity did not prevent the deleterious effects of MPI on larval growth. The introduction of the mpi gene into rice plants can thus be considered as a promising strategy to protect rice plants against striped stem borer.

  11. Ethylene production and peroxidase activity in aphid-infested barley.

    Science.gov (United States)

    Argandoña, V H; Chaman, M; Cardemil, L; Muñoz, O; Zúñiga, G E; Corcuera, L J

    2001-01-01

    The purpose of this work was to investigate whether ethylene is involved in the oxidative and defensive responses of barley to the aphids Schizaphis graminum (biotype C) and Rhopalophum padi. The effect of aphid infestation on ethylene production was measured in two barley cultivars (Frontera and Aramir) that differ in their susceptibility to aphids. Ethylene evolution was higher in plants infested for 16 hr than in plants infested for 4 hr in both cultivars. Under aphid infestation, the production of ethylene was higher in cv. Frontera than in Aramir, the more aphid susceptible cultivar. Ethylene production also increases with the degree of infestation. Maximum ethylene evolution was detected after 16 hr when plants were infested with 10 or more aphids. Comparing the two species of aphids, Schizaphis graminum induced more ethylene evolution than Rhopalosiphum padi. Infestation with S. graminum increased hydrogen peroxide content and total soluble peroxidase activity in cv. Frontera, with a maximum level of H2O2 observed after 20 min of infestation and the maximum in soluble peroxidase activity after 30 min of infestation. When noninfested barley seedlings from cv. Frontera were exposed to ethylene, an increase in hydrogen peroxide and in total peroxidase activity was detected at levels similar to those of infested plants from cv. Frontera. When noninfested plants were treated with 40 ppm of ethylene, the maximum levels of H2O2 and soluble peroxidase activity were at 10 and 40 min, respectively. Ethylene also increased the activity of both cell-wall-bound peroxidases types (ionically and covalently bound), comparable with infestation. These results suggest that ethylene is involved in the oxidative responses of barley plants induced by infestation.

  12. A review of the nest protection hypothesis: does inclusion of fresh green plant material in birds' nests reduce parasite infestation?

    Science.gov (United States)

    Scott-Baumann, James F; Morgan, Eric R

    2015-07-01

    The use of aromatic plants and their essential oils for ectoparasite treatment is a field of growing interest. Several species of birds regularly introduce aromatic herbs into their nests putatively to reduce parasites. The behaviour is most often seen in cavity nesting birds and after nest building has finished. The plants are included in a non-structural manner and are often strongly aromatic. Various different hypotheses have been proposed regarding the function of this behaviour; from the plants altering some non-living factor in the nest (crypsis, water loss and insulation hypotheses) to them being involved in mate selection (mate hypothesis) or even having a beneficial effect, direct or indirect, on chicks (drug or nest protection hypothesis, NPH). Many studies have been carried out over the years observing and experimentally testing these hypotheses. This review focuses on studies involving the most popular of these hypotheses, the NPH: that plants decrease nest parasites or pathogens, thereby conveying positive effects to the chicks, allowing the behaviour to evolve. Studies providing observational evidence towards this hypothesis and those experimentally testing it are discussed.

  13. Cross-tolerance to biotic and abiotic stresses in plants: a focus on resistance to aphid infestation.

    Science.gov (United States)

    Foyer, Christine H; Rasool, Brwa; Davey, Jack W; Hancock, Robert D

    2016-03-01

    Plants co-evolved with an enormous variety of microbial pathogens and insect herbivores under daily and seasonal variations in abiotic environmental conditions. Hence, plant cells display a high capacity to respond to diverse stresses through a flexible and finely balanced response network that involves components such as reduction-oxidation (redox) signalling pathways, stress hormones and growth regulators, as well as calcium and protein kinase cascades. Biotic and abiotic stress responses use common signals, pathways and triggers leading to cross-tolerance phenomena, whereby exposure to one type of stress can activate plant responses that facilitate tolerance to several different types of stress. While the acclimation mechanisms and adaptive responses that facilitate responses to single biotic and abiotic stresses have been extensively characterized, relatively little information is available on the dynamic aspects of combined biotic/abiotic stress response. In this review, we consider how the abiotic environment influences plant responses to attack by phloem-feeding aphids. Unravelling the signalling cascades that underpin cross-tolerance to biotic and abiotic stresses will allow the identification of new targets for increasing environmental resilience in crops.

  14. Effects of plant tannin extracts supplementation on animal performance and gastrointestinal parasites infestation in steers grazing winter wheat

    Science.gov (United States)

    Twenty-six stocker cattle (286.1 ± 25.7 kg) were used to quantify the effect of commercial plant tannin extracts (control vs. mimosa and chestnut tannins) on animal performance, gastrointestinal parasites control, and plasma metabolite changes in heifers grazing winter wheat forage (Triticum aestivu...

  15. Within-plant distribution and seasonal population dynamics of flower thrips (Thysanoptera: Thripidae) infesting French beans (Phaseolus vulgaris L.) in Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Kasina, M.; Nderitu, J.; Nyamasyo, G.; Waturu, C.; Olubayo, F.; Obudho, E.; Yobera, D.

    2009-07-01

    The aim of this research was to study spatial distribution of flower thrips on French beans (Phaseolus vulgaris L.) in Kenya. Their build up and seasonal population dynamics was monitored using sticky blue colour traps and sampling of leaves and flowers in two seasons in 2002. Thrips infested French beans from the second week after crop emergence. Their population peaked at peak flowering. The sticky trap catches were linearly related to the actual presence of thrips on the crop and could estimate population build up of adult thrips on leaves and flowers. On the plants, most adults were on flowers. Larvae mainly inhabited leaves, buds and pods. The two thrips species, Frankliniella occidentalis (Pergande) and Megalurothrips sjostedti Trybom were spatially separated. The former colonized lower-canopy leaves and early flowers while the latter inhabited middle-canopy leaves and mature flowers. Overall, M. sjostedti was less than 5% of the total thrips population, implying that F. occidentalis was the main thrips pest of French beans. This study suggests that French bean growers should monitor thrips population before initiating any control measure. In addition, they should commence thrips control early, at pre-flowering, using larvicides to reduce the thrips pool and their migration to flowers. A combination of monitoring with sticky traps and proper sampling would contribute to sustainable thrips management. (Author) 36 refs.

  16. Whole-genome resequencing and transcriptomic analysis to identify genes involved in leaf-color diversity in ornamental rice plants.

    Directory of Open Access Journals (Sweden)

    Chang-Kug Kim

    Full Text Available Rice field art is a large-scale art form in which people design rice fields using various kinds of ornamental rice plants with different leaf colors. Leaf color-related genes play an important role in the study of chlorophyll biosynthesis, chloroplast structure and function, and anthocyanin biosynthesis. Despite the role of different metabolites in the traditional relationship between leaf and color, comprehensive color-specific metabolite studies of ornamental rice have been limited. We performed whole-genome resequencing and transcriptomic analysis of regulatory patterns and genetic diversity among different rice cultivars to discover new genetic mechanisms that promote enhanced levels of various leaf colors. We resequenced the genomes of 10 rice leaf-color accessions to an average of 40× reads depth and >95% coverage and performed 30 RNA-seq experiments using the 10 rice accessions sampled at three developmental stages. The sequencing results yielded a total of 1,814 × 106 reads and identified an average of 713,114 SNPs per rice accession. Based on our analysis of the DNA variation and gene expression, we selected 47 candidate genes. We used an integrated analysis of the whole-genome resequencing data and the RNA-seq data to divide the candidate genes into two groups: genes related to macronutrient (i.e., magnesium and sulfur transport and genes related to flavonoid pathways, including anthocyanidin biosynthesis. We verified the candidate genes with quantitative real-time PCR using transgenic T-DNA insertion mutants. Our study demonstrates the potential of integrated screening methods combined with genetic-variation and transcriptomic data to isolate genes involved in complex biosynthetic networks and pathways.

  17. Whole-Genome Resequencing and Transcriptomic Analysis to Identify Genes Involved in Leaf-Color Diversity in Ornamental Rice Plants

    Science.gov (United States)

    Shin, Younhee; Lim, Hye-Min; Lee, Gang-Seob; Kim, A-Ram; Lee, Tae-Ho; Lee, Jae-Hee; Park, Dong-Suk; Yoo, Seungil; Kim, Yong-Hwan; Kim, Yong-Kab

    2015-01-01

    Rice field art is a large-scale art form in which people design rice fields using various kinds of ornamental rice plants with different leaf colors. Leaf color-related genes play an important role in the study of chlorophyll biosynthesis, chloroplast structure and function, and anthocyanin biosynthesis. Despite the role of different metabolites in the traditional relationship between leaf and color, comprehensive color-specific metabolite studies of ornamental rice have been limited. We performed whole-genome resequencing and transcriptomic analysis of regulatory patterns and genetic diversity among different rice cultivars to discover new genetic mechanisms that promote enhanced levels of various leaf colors. We resequenced the genomes of 10 rice leaf-color accessions to an average of 40× reads depth and >95% coverage and performed 30 RNA-seq experiments using the 10 rice accessions sampled at three developmental stages. The sequencing results yielded a total of 1,814 × 106 reads and identified an average of 713,114 SNPs per rice accession. Based on our analysis of the DNA variation and gene expression, we selected 47 candidate genes. We used an integrated analysis of the whole-genome resequencing data and the RNA-seq data to divide the candidate genes into two groups: genes related to macronutrient (i.e., magnesium and sulfur) transport and genes related to flavonoid pathways, including anthocyanidin biosynthesis. We verified the candidate genes with quantitative real-time PCR using transgenic T-DNA insertion mutants. Our study demonstrates the potential of integrated screening methods combined with genetic-variation and transcriptomic data to isolate genes involved in complex biosynthetic networks and pathways. PMID:25897514

  18. Bacillus oryzicola sp. nov., an Endophytic Bacterium Isolated from the Roots of Rice with Antimicrobial, Plant Growth Promoting, and Systemic Resistance Inducing Activities in Rice.

    Science.gov (United States)

    Chung, Eu Jin; Hossain, Mohammad Tofajjal; Khan, Ajmal; Kim, Kyung Hyun; Jeon, Che Ok; Chung, Young Ryun

    2015-06-01

    Biological control of major rice diseases has been attempted in several rice-growing countries in Asia during the last few decades and its application using antagonistic bacteria has proved to be somewhat successful for controlling various fungal diseases in field trials. Two novel endophytic Bacillus species, designated strains YC7007 and YC7010(T), with anti-microbial, plant growth-promoting, and systemic resistance-inducing activities were isolated from the roots of rice in paddy fields at Jinju, Korea, and their multifunctional activities were analyzed. Strain YC7007 inhibited mycelial growth of major rice fungal pathogens strongly in vitro. Bacterial blight and panicle blight caused by Xanthomonas oryzae pv. oryzae (KACC 10208) and Burkholderia glumae (KACC 44022), respectively, were also suppressed effectively by drenching a bacterial suspension (10(7) cfu/ml) of strain YC7007 on the rhizosphere of rice. Additionally, strain YC7007 promoted the growth of rice seedlings with higher germination rates and more tillers than the untreated control. The taxonomic position of the strains was also investigated. Phylogenetic analyses based on 16S rRNA gene sequences indicated that both strains belong to the genus Bacillus, with high similarity to the closely related strains, Bacillus siamensis KACC 15859(T) (99.67%), Bacillus methylotrophicus KACC 13105(T) (99.65%), Bacillus amyloliquefaciens subsp. plantarum KACC 17177(T) (99.60%), and Bacillus tequilensis KACC 15944(T) (99.45%). The DNA-DNA relatedness value between strain YC7010(T) and the most closely related strain, B. siamensis KACC 15859(T) was 50.4±3.5%, but it was 91.5±11.0% between two strains YC7007 and YC7010(T), indicating the same species. The major fatty acids of two strains were anteiso-C15:0 and iso C15:0. Both strains contained MK-7 as a major respiratory quinone system. The G+C contents of the genomic DNA of two strains were 50.5 mol% and 51.2 mol%, respectively. Based on these polyphasic studies

  19. Bacillus oryzicola sp. nov., an Endophytic Bacterium Isolated from the Roots of Rice with Antimicrobial, Plant Growth Promoting, and Systemic Resistance Inducing Activities in Rice

    Directory of Open Access Journals (Sweden)

    Eu Jin Chung

    2015-06-01

    Full Text Available Biological control of major rice diseases has been attempted in several rice-growing countries in Asia during the last few decades and its application using antagonistic bacteria has proved to be somewhat successful for controlling various fungal diseases in field trials. Two novel endophytic Bacillus species, designated strains YC7007 and YC7010T, with anti-microbial, plant growth-promoting, and systemic resistance-inducing activities were isolated from the roots of rice in paddy fields at Jinju, Korea, and their multifunctional activities were analyzed. Strain YC7007 inhibited mycelial growth of major rice fungal pathogens strongly in vitro. Bacterial blight and panicle blight caused by Xanthomonas oryzae pv. oryzae (KACC 10208 and Burkholderia glumae (KACC 44022, respectively, were also suppressed effectively by drenching a bacterial suspension (10⁷ cfu/ml of strain YC7007 on the rhizosphere of rice. Additionally, strain YC7007 promoted the growth of rice seedlings with higher germination rates and more tillers than the untreated control. The taxonomic position of the strains was also investigated. Phylogenetic analyses based on 16S rRNA gene sequences indicated that both strains belong to the genus Bacillus, with high similarity to the closely related strains, Bacillus siamensis KACC 15859T (99.67%, Bacillus methylotrophicus KACC 13105T (99.65%, Bacillus amyloliquefaciens subsp. plantarum KACC 17177T (99.60%, and Bacillus tequilensis KACC 15944T (99.45%. The DNA-DNA relatedness value between strain YC7010T and the most closely related strain, B. siamensis KACC 15859T was 50.4±3.5%, but it was 91.5±11.0% between two strains YC7007 and YC7010T, indicating the same species. The major fatty acids of two strains were anteiso-C15:0 and iso C15:0. Both strains contained MK-7 as a major respiratory quinone system. The G+C contents of the genomic DNA of two strains were 50.5 mol% and 51.2 mol%, respectively. Based on these polyphasic studies, the

  20. [Effects of increased planting density with reduced nitrogen fertilizer application on rice yield, N use efficiency and greenhouse gas emission in Northeast China].

    Science.gov (United States)

    Zhu, Xiang-cheng; Zhang, Zhen-ping; Zhang, Jun; Deng, Ai-xing; Zhang, Wei-jian

    2016-02-01

    The traditional rice growing practice has to change to save resource and protect environment, and it' s necessary to develop new technology in rice cultivation. Therefore, a two-year field experiment of Japonica rice (Liaoxing 1) was conducted in Northeast China in 2012 and 2013 to investigate the integrated effects of dense planting with less basal nitrogen (N) and unchanged top-dressing N (IR) on rice yield, N use efficiency (NUE) and greenhouse gas emissions. Compared with traditional practice (CK), we increased the rice seedling density by 33.3% and reduced the basal N rate by 20%. The results showed that the average N agronomy efficiency and partial factor productivity were improved by 49.6% (Pefficiency. Generally, proper dense planting with less basal N applicatior could be a good approach for the trade-off between rice yield, NUE and greenhouse gas emission.

  1. Exogenously Applied Plant Growth Regulators Enhance the Morpho-Physiological Growth and Yield of Rice under High Temperature.

    Science.gov (United States)

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Hassan, Shah; Ihsan, Zahid; Shah, Adnan N; Wu, Chao; Yousaf, Muhammad; Nasim, Wajid; Alharby, Hesham; Alghabari, Fahad; Huang, Jianliang

    2016-01-01

    A 2-year experiment was conducted to ascertain the effects of exogenously applied plant growth regulators (PGR) on rice growth and yield attributes under high day (HDT) and high night temperature (HNT). Two rice cultivars (IR-64 and Huanghuazhan) were subjected to temperature treatments in controlled growth chambers and four different combinations of ascorbic acid (Vc), alpha-tocopherol (Ve), brassinosteroids (Br), methyl jasmonates (MeJA), and triazoles (Tr) were applied. High temperature severely affected rice morphology, and also reduced leaf area, above-, and below-ground biomass, photosynthesis, and water use efficiency, while increased the leaf water potential of both rice cultivars. Grain yield and its related attributes except number of panicles, were reduced under high temperature. The HDT posed more negative effects on rice physiological attributes, while HNT was more detrimental for grain formation and yield. The Huanghuazhan performed better than IR-64 under high temperature stress with better growth and higher grain yield. Exogenous application of PGRs was helpful in alleviating the adverse effects of high temperature. Among PGR combinations, the Vc+Ve+MejA+Br was the most effective treatment for both cultivars under high temperature stress. The highest grain production by Vc+Ve+MejA+Br treated plants was due to enhanced photosynthesis, spikelet fertility and grain filling, which compensated the adversities of high temperature stress. Taken together, these results will be of worth for further understanding the adaptation and survival mechanisms of rice to high temperature and will assist in developing heat-resistant rice germplasm in future.

  2. Exogenously applied plant growth regulators enhance the morpho-physiological growth and yield of rice under high temperature

    Directory of Open Access Journals (Sweden)

    Shah Fahad

    2016-08-01

    Full Text Available A two-year experiment was conducted to ascertain the effects of exogenously applied plant growth regulators (PGR on rice growth and yield attributes under high day (HDT and high night temperature (HNT. Two rice cultivars (IR-64 and Huanghuazhan were subjected to temperature treatments in controlled growth chambers and four different combinations of ascorbic acid (Vc, alpha-tocopherol (Ve, brassinosteroids (Br, methyl jasmonates (MeJA and triazoles (Tr were applied. High temperature severely affected rice morphology, and also reduced leaf area, above- and below-ground biomass, photosynthesis, and water use efficiency, while increased the leaf water potential of both rice cultivars. Grain yield and its related attributes except number of panicles, were reduced under high temperature. The HDT posed more negative effects on rice physiological attributes, while HNT was more detrimental for grain formation and yield. The Huanghuazhan performed better than IR-64 under high temperature stress with better growth and higher grain yield. Exogenous application of PGRs was helpful in alleviating the adverse effects of high temperature. Among PGR combinations, the Vc+Ve+MejA+Br was the most effective treatment for both cultivars under high temperature stress. The highest grain production by Vc+Ve+MejA+Br treated plants was due to enhanced photosynthesis, spikelet fertility and grain filling, which compensated the adversities of high temperature stress. Taken together, these results will be of worth for further understanding the adaptation and survival mechanisms of rice to high temperature and will assist in developing heat-resistant rice germplasm in future.

  3. Cultivar specific plant-soil feedback overrules soil legacy effects of elevated ozone in a rice-wheat rotation system

    NARCIS (Netherlands)

    Li, Qi; Yang, Yue; Bao, Xuelian; Zhu, Jianguo; Liang, Wenju; Bezemer, T. Martijn

    2016-01-01

    Abstract Tropospheric ozone has been recognized as one of the most important air pollutants. Many studies have shown that elevated ozone negatively impacts yields of important crops such as wheat or rice, but how ozone influences soil ecosystems of these crops and plant growth in rotation systems is

  4. Cultivar specific plant-soil feedback overrules soil legacy effects of elevated ozone in a rice-wheat rotation system

    NARCIS (Netherlands)

    Li, Qi; Yang, Yue; Bao, Xuelian; Zhu, Jianguo; Liang, Wenju; Bezemer, T. Martijn

    2016-01-01

    Abstract Tropospheric ozone has been recognized as one of the most important air pollutants. Many studies have shown that elevated ozone negatively impacts yields of important crops such as wheat or rice, but how ozone influences soil ecosystems of these crops and plant growth in rotation systems is

  5. Induction of toxin-specific neutralizing immunity by molecularly uniform rice-based oral cholera toxin B subunit vaccine without plant-associated sugar modification.

    Science.gov (United States)

    Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Hiroiwa, Tomoko; Takahashi, Yuko; Tokuhara, Daisuke; Nochi, Tomonori; Katakai, Yuko; Kuroda, Masaharu; Takeyama, Natsumi; Kashima, Koji; Abe, Michiyo; Chen, Yingju; Nakanishi, Ushio; Masumura, Takehiro; Takeuchi, Yoji; Kozuka-Hata, Hiroko; Shibata, Hiroaki; Oyama, Masaaki; Tanaka, Kunisuke; Kiyono, Hiroshi

    2013-09-01

    Plants have been used as expression systems for a number of vaccines. However, the expression of vaccines in plants sometimes results in unexpected modification of the vaccines by N-terminal blocking and sugar-chain attachment. Although MucoRice-CTB was thought to be the first cold-chain-free and unpurified oral vaccine, the molecular heterogeneity of MucoRice-CTB, together with plant-based sugar modifications of the CTB protein, has made it difficult to assess immunological activity of vaccine and yield from rice seed. Using a T-DNA vector driven by a prolamin promoter and a signal peptide added to an overexpression vaccine cassette, we established MucoRice-CTB/Q as a new generation oral cholera vaccine for humans use. We confirmed that MucoRice-CTB/Q produces a single CTB monomer with an Asn to Gln substitution at the 4th glycosylation position. The complete amino acid sequence of MucoRice-CTB/Q was determined by MS/MS analysis and the exact amount of expressed CTB was determined by SDS-PAGE densitometric analysis to be an average of 2.35 mg of CTB/g of seed. To compare the immunogenicity of MucoRice-CTB/Q, which has no plant-based glycosylation modifications, with that of the original MucoRice-CTB/N, which is modified with a plant N-glycan, we orally immunized mice and macaques with the two preparations. Similar levels of CTB-specific systemic IgG and mucosal IgA antibodies with toxin-neutralizing activity were induced in mice and macaques orally immunized with MucoRice-CTB/Q or MucoRice-CTB/N. These results show that the molecular uniformed MucoRice-CTB/Q vaccine without plant N-glycan has potential as a safe and efficacious oral vaccine candidate for human use.

  6. Growth and Productivity of Response of Hybrid Rice to Application of Animal Manures, Plant Residues and Phosphorus

    Directory of Open Access Journals (Sweden)

    Dr. Amanullah

    2016-10-01

    Full Text Available The objective of this research was to evaluate the impact of organic sources (animal manures vs. plant residues at the rate of 10 t ha-1 each on the productivity profitability of small land rice (Oryza sativa L. grower under different levels of phosphorus (0, 30, 60 and 90 kg P ha-1 fertilization. Two separate field experiments were conducted. In experiment (1, impact of three animal manures sources (cattle, sheep & poultry manures and P levels was studied along with one control plot (no animal manure and P applied as check was investigated. In experiment (2, three plant residues sources (peach leaves, garlic residues & wheat straw and P levels was studied along with one control plot (no plant residues and P applied as check. Both the experiments were carried out on small land farmer field at District Swabi, Khyber Pakhtunkhwa Province (Northwest Pakistan during summer 2015. The results revealed that in both experiments the control plot had significantly (p≤0.05 less productivity than the average of all treated plots with organic sources and P level. The increase in P levels in both experiments (animal manure vs. plant residues had resulted in higher rice productivity (90 = 60 > 30 > 0 kg P ha-1. In the experiment under animal manures, application of poultry manure increased rice productivity as compared with sheep and cattle manures (poultry > sheep > cattle manures. In the experiment under plant residues, application of peach leaves or garlic resides had higher rice productivity over wheat straw (peach leaves = garlic residues > wheat straw. On the average, the rice grown under animal manures produced about 20% higher grain yield than the rice grown under crop residues. We concluded from this study that application of 90 kg P ha-1 along with combined application of animal manures especially poultry manure could increase rice productivity. We conclude from this study that application of 90 kg P ha-1 along with combined application of animal

  7. Retromer Is Essential for Autophagy-Dependent Plant Infection by the Rice Blast Fungus

    Science.gov (United States)

    He, Yunlong; Xie, Qiurong; Chen, Ahai; Zheng, Huawei; Shi, Lei; Zhao, Xu; Zhang, Chengkang; Huang, Qingping; Fang, Kunhai; Lu, Guodong; Ebbole, Daniel J.; Li, Guangpu; Naqvi, Naweed I.; Wang, Zonghua

    2015-01-01

    The retromer mediates protein trafficking through recycling cargo from endosomes to the trans-Golgi network in eukaryotes. However, the role of such trafficking events during pathogen-host interaction remains unclear. Here, we report that the cargo-recognition complex (MoVps35, MoVps26 and MoVps29) of the retromer is essential for appressorium-mediated host penetration by Magnaporthe oryzae, the causal pathogen of the blast disease in rice. Loss of retromer function blocked glycogen distribution and turnover of lipid bodies, delayed nuclear degeneration and reduced turgor during appressorial development. Cytological observation revealed dynamic MoVps35-GFP foci co-localized with autophagy-related protein RFP-MoAtg8 at the periphery of autolysosomes. Furthermore, RFP-MoAtg8 interacted with MoVps35-GFP in vivo, RFP-MoAtg8 was mislocalized to the vacuole and failed to recycle from the autolysosome in the absence of the retromer function, leading to impaired biogenesis of autophagosomes. We therefore conclude that retromer is essential for autophagy-dependent plant infection by the rice blast fungus. PMID:26658729

  8. Compatibility study of Trichoderma harzianum Rifai and rice fungicides, and effects on three fungal plant pathogens

    Directory of Open Access Journals (Sweden)

    Manuel Francisco Rodríguez Saldaña

    2017-04-01

    Full Text Available This research took place at the Provincial Plant Sanitation Laboratory, in Camaguey, Cuba, between September 2013 and September 2015. The in vitro compatibility and antagonistic capacity of Trichoderma harzianum Rifai (strain A-34 on rice pathogens (Bipolaris oryzae Breda de Haan, Sarocladium oryzae (Sawada w., Gams and D. Hawksworth and Magnaporthe grisea (Hebert Barr, was determined against pesticides used on rice. Assessment using traditional methods of microbiological isolation of mycelial growth, sporulation and conidial germination of the antagonist, to determine if the action mechanisms (antibiosis, competence, parasitism against fungal pathogens, was made between 24 and 216 hours of application. A bifactorial design in dual culture was used for statistical analysis, along with scales for determination of microbial antagonistic capacity. Active ingredients tebuconazol + procloraz, trifloxistrobin+ ciproconazole, and epoxiconazole + kresoxim-methyl, affected mycelial growth of the antagonist. Moreover, the antagonist against active ingredients carbendazim, copper oxychloride, azoxystrobin and tebuconazo + triadimenol showed mycelial growth, sporulation and pathogen interaction, affecting their growth by means of coiling, penetration, granulation, and cell lysis, between 96 and 216 hours.

  9. Evaluation of plant growth promoting and colonization ability of endophytic diazotrophs from deep water rice.

    Science.gov (United States)

    Verma, S C; Ladha, J K; Tripathi, A K

    2001-10-04

    A study of the diversity of endophytic bacteria present in seeds of a deepwater rice variety revealed the presence of seven types of BOX-PCR fingerprints. In order to evaluate the plant growth promoting potential the presence of nitrogenase, indole acetic acid production and mineral phosphate solubilization were estimated in the representative BOX-PCR types. The seven representatives of BOX-PCR types produced indole acetic acid, reduced acetylene and showed specific immunological cross-reaction with anti-dinitrogenase reductase antibody. Only four types showed mineral phosphate solubilizing ability. Comparison of cellulase and pectinase activities showed differences among different BOX-PCR types. PCR fingerprinting data showed that one strain isolated from the surface sterilized seeds as well as the aerial parts of the seedlings of rice variety showed low cellulase and pectinase but relatively high ARA. On the basis of 16S rDNA nucleotide sequence and BIOLOG system of bacterial identification, this strain was identified as Pantoea agglomerans. For studying the endophytic colonization this strain was genetically tagged with the reporter gene, gusA. Histochemical analysis of the seedling grown in hydroponics showed that the tagged strain colonized the root surface, root hairs, root cap, points of lateral root emergence, root cortex and the stelar region. Treatment of the roots with 2,4-D produced short thickened lateral roots which showed better colonization by P. agglomerans.

  10. Distribution of Leaf Color and Nitrogen Nutrition Diagnosis in Rice Plant

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-hua; CAO Wei-xing; WANG Qiang-sheng; DING Yan-feng; HUANG Pi-sheng; LING Qi-hong

    2002-01-01

    Greenness and nitrogen content of each leaf on main stem of different japonica and indica ricevarieties under different nitrogen levels were investigated. Results showed that the fourth leaf from the top ex-hibited active changes with the change of plant nitrogen status. When the plant nitrogen content was low, itscolor and nitrogen content were obviously lower than those of the three top leaves. With the increase of plantnitrogen content, the color and nitrogen content of the fourth leaf increased quickly, and the differences ofcolor and nitrogen content between the fourth leaf and the three top leaves decreased. So, the fourth leaf wasan ideal indication of plant nutrition status. In addition, color difference between the fourth and the third leaffrom the top was highly related to the plant nitrogen content regardless of the variety and development stage.Therefore, color difference between the fourth and the third leaf could be widely used for diagnosis of plantnutrition. Results also indicated that the minimized color difference between the fourth and the third leaf at the criticaleffective tillering, the emergence of the second leaf from the top, and the heading was the symbol of high yield. Plantnitrogen content of 27 g kg-1 DW for japonica rice and 25 g kg-1 DW for indica were the critical nitrogen concentrations.

  11. Generation and Analysis of Transposon Ac/Ds-Induced Chromosomal Rearrangements in Rice Plants.

    Science.gov (United States)

    Xuan, Yuan Hu; Peterson, Thomas; Han, Chang-Deok

    2016-01-01

    Closely-located transposable elements (TEs) have been known to induce chromosomal breakage and rearrangements via alternative transposition. To study genome rearrangements in rice, an Ac/Ds system has been employed. This system comprises an immobile Ac element expressed under the control of CaMV 35S promoter, and a modified Ds element. A starter line carried Ac and a single copy of Ds at the OsRLG5 (Oryza sativa receptor-like gene 5). To enhance the transpositional activity, seed-derived calli were cultured and regenerated into plants. Among 270 lines regenerated from the starter, one line was selected that contained a pair of inversely-oriented Ds elements at the OsRLG5 (Oryza sativa receptor-like gene 5). The selected line was again subjected to tissue culture to obtain a regenerant population. Among 300 regenerated plants, 107 (36 %) contained chromosomal rearrangements including deletions, duplications, and inversions of various sizes. From 34 plants, transposition mechanisms leading to such genomic rearrangements were analyzed. The rearrangements were induced by sister chromatid transposition (SCT), homologous recombination (HR), and single chromatid transposition (SLCT). Among them, 22 events (65 %) were found to be transmitted to the next generation. These results demonstrate a great potential of tissue culture regeneration and the Ac/Ds system in understanding alternative transposition mechanisms and in developing chromosome engineering in plants.

  12. Estimation of the rice-planting field in Bangladesh by satellite remote sensing

    Science.gov (United States)

    Furuta, E.; Suzuki, G.; Yamassaki, M.; Teraoka, T.; Fujiwara, H.; Ogino, Y.; Akashi, M.; Lahrita, L.; Naruse, N.; Takahashi, Y.

    2016-12-01

    In Bangladesh, price of rice has been unstable due to a large increase in production. To control the price can become a political issue, because rice agriculture is one of the most important industries in Bangladesh, whereas the total area of the paddy field is accurately unknown, owing to unsustainable and on-site surveys for the area (1). Satellite remote sensing is an effective solution to research the all area of domestic paddy field. Microwave satellite imaging has a large merit to be observable regardless of the weather conditions, however, research institutions have been limited to observing continuously since the cost is high for developing countries, such as Bangladesh. This study aims to establish the way to grasp the paddy field using optical satellite images for free of charge (Landsat-8). We have focused on seasonal changes in the water and the vegetation indices obtained from paddy fields. We have performed image calculations of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) of the well-known paddy field in Bangladesh Rice Research Institute. We found that there are seasonal changes of NDVI and NDWI calculated from paddy field. The characteristics are as follows; the NDVI and the NDWI values varies by 0.17-0.25 up and 0.11-0.19 down, respectively, at the transition from the dry to the rainy season, on the other hand, the NDVI and the NDWI changes by 0.21-0.29 down and 0.09-0.17 up from the rainy to the dry season. These features make us to distinguish the paddy field from the other cultivated area. The decrease of NDVI means that rice bares, The increase of NDWI can be interpreted that the paddy field is covered with water for the preparation for planting it. Our estimated area of paddy field in Bangladesh (85,900km ) corresponds well with the previous reported value of 117,700km (1). We have established the way to grasp the paddy field using optical satellite images for free of charge, on the bases of the

  13. DYNAMICS OF K +, NA +, CA2 + IONS IN RICE PLANTS (Oryza sativa L. IN ONTOGENESIS UNDER SOIL SALINITY

    Directory of Open Access Journals (Sweden)

    Tkacheva M. S.

    2014-06-01

    Full Text Available Under conditions of vegetation experiment at soil artificial chloride salinization the dynamics of accumulation and distribution of sodium, potassium and calcium in organs of rice plants (Oryza sativa L. have been studied, as well as their correlation with tissue hydration in ontogenesis. The significant restriction of salinization ions transport and accumulation, particularly sodium, in the actively functioning upper leaves and panicles has been observed. Whereas the content of calcium and potassium in the experimental and control plants differed slightly

  14. Influence of nutrient composition and plant growth regulators on callus induction and plant regeneration in glutinous rice (Oryza sativa L.).

    Science.gov (United States)

    Duangsee, K; Bunnag, S

    2014-01-01

    The potential for callus induction and regeneration depends on nutrient composition and plant growth regulators. The aim of the present study was to investigate the effect of nutrient composition and plant growth regulators on callus induction and plant regeneration in the glutinous rice cultivar Khunvang. The effect of 2,4-D concentrations (1, 2, 3, 4 and 5 mg L(-1)) on callus induction and growth were investigated. The results revealed that the highest percentage of callus induction (97%) was observed in MS medium supplemented with 5 mg L(-1) 2,4-D under 16 h Photoperiod. The effects of casein hydrolysate concentrations of casein hydrolysate (0, 300, 500, 700 and 900 mg L(-1)) and proline (0, 300, 500, 700 and 900 mg L(-1)) on callus induction and growth of Khunvang were also observed. The results indicated that the increasing casein hydrolysate and proline concentrations did not show a significant effect on callus growth. However, proline concentration of 900 mg L(-1) yielded 85.67% of callus growth.

  15. Circumnutation and its dependence on the gravity response in rice, morning glory and pea plants: verification by spaceflight experiments

    Science.gov (United States)

    Takahashi, Hideyuki; Kobayashi, Akie; Fujii, Nobuharu; Yano, Sachiko; Shimazu, Toru; Kim, Hyejeong; Tomita, Yuuta; Miyazawa, Yutaka

    Plant organs display helical growth movement known as circumnutation. This movement helps plant organs find suitable environmental cues. The amplitude, period and shape of the circumnutation differ depending on plant species or organs. Although the mechanism for circumnutation is unclear, it has long been argued whether circumnutation is involved with gravitropic response. Previously, we showed that shoots of weeping morning glory (we1 and we2) are impaired in not only the differentiation of endodermis (gravisensing cells) and gravitropic response, but also winding and circumnutation (Kitazawa et al., PNAS 102: 18742-18747, 2005). Here, we report a reduced circumnutation in the shoots of rice and the roots of pea mutants defective in gravitropic response. Coleoptiles of clinorotated rice seedlings and decapped roots of pea seedlings also showed a reduction of their circumnutational movement. These results suggest that circumnutation is tightly related with gravitropic response. In the proposed spaceflight experiments, “Plant Rotation”, we will verify the hypothesis that circumnutation requires gravity response, by using microgravity environment in KIBO module of the International Space Station. We will grow rice and morning glory plants under both muG and 1G conditions on orbit and monitor their growth by a camera. The downlinked images will be analyzed for the measurements of plant growth and nutational movements. This experiment will enable us to answer the question whether circumnutation depends on gravity response or not.

  16. Treatment of scabies infestations

    Directory of Open Access Journals (Sweden)

    Mumcuoglu K.Y.

    2008-09-01

    Full Text Available Scabies is an intensely pruritic disorder induced by an immune allergic response to infestation of the skin by the mite Sarcoptes scabiei. The biology of the mite, the clinical aspects and diagnosis of scabies infestations as well as the treatment of choice with 5 % permethrin dermal cream and the use of scabicides based on other chemical substances are reviewed.

  17. Qualitative and Quantitative Differences in Herbivore-Induced Plant Volatile Blends from Tomato Plants Infested by Either Tuta absoluta or Bemisia tabaci

    NARCIS (Netherlands)

    Bastos Silva, Diego; Weldegergis, Berhane T.; Loon, van Joop J.A.; Bueno, Vanda H.P.

    2017-01-01

    Plants release a variety of volatile organic compounds that play multiple roles in the interactions with other plants and animals. Natural enemies of plant-feeding insects use these volatiles as cues to find their prey or host. Here, we report differences between the volatile blends of tomato pla

  18. Influence of irradiated chitosan on rice plants growing in hydroponic medium contaminated with salt and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Lam, N.D.; Diep, T.B. [Institute for Nuclear Science and Technique-VAEC, Nghiado, Cau giay, Hanoi (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Effect of chitosan and radiation-degraded chitosan on rice seedlings of a Vietnam's original variety was investigated. Potential of irradiated chitosan in plant tolerance for several stress factors (salt, zinc, and vanadium) also was studied as well. Chitosan represented in hydroponic medium clearly inhibited the growth of rice seedlings at concentrations arranging from 50 ppm. Radiation processing of chitosan with dose higher than 100 kGy reduced toxicity of chitosan and the efficacy was of dose proportion. Rice plant of 203 origin was almost normally grown in hydroponic solution containing chitosan that has been irradiated with dose of 150 and 200 kGy. Irradiated chitosan increased plant resistance to environmental stress caused by vanadium (V); thereby the seedlings could be recovered completely, even gained in biomass. This effect was not appeared when applied chitosan to rice in media contaminated by zinc (Zn) and salt (NaCl). The selectness of irradiated chitosan on various stress factors partly clarified the assistant action of chitosan in the vanadium intoxication because chelating with metal ions could not be evaluated as main mechanism. (author)

  19. Water, Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

    Institute of Scientific and Technical Information of China (English)

    Maite MART(I)NEZ-EIXARCH; ZHU De-feng; Maria del Mar CATAL(A)-FORNER; Eva PLA-MAYOR; Nuria TOM(A)S-NAVARRO

    2013-01-01

    Field experiments were conducted in the Ebro Delta area (Spain),from 2007 to 2009 with two rice varieties:Gleva and Tebre.The experimental treatments included a series of seed rates,two different water management systems and two different nitrogen fertilization times.The number of leaves on the main stems and their emergence time were periodically tagged.The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles.Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems.Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems.Final leaf number on the main stems was negatively related to plant density.A relationship between leaf appearance and thermal time was established with a strong nonlinear function.In direct-seeded rice,the length of the phyllochron increases exponentially in line with the advance of plant development.A general model,derived from 2-year experimental data,was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf.An exponential model can be used to predict leaf emergence in direct-seeded rice.

  20. Water, Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

    Directory of Open Access Journals (Sweden)

    Maite MARTÍNEZ-EIXARCH

    2013-01-01

    Full Text Available Field experiments were conducted in the Ebro Delta area (Spain, from 2007 to 2009 with two rice varieties: Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.

  1. An osmotin from the resurrection plant Tripogon loliiformis (TlOsm) confers tolerance to multiple abiotic stresses in transgenic rice.

    Science.gov (United States)

    Le, Trang T T; Williams, Brett; Mundree, Sagadevan G

    2017-05-03

    Osmotin is a key protein associated with abiotic and biotic stress response in plants. In this study, an osmotin from the resurrection plant Tripogon loliiformis (TlOsm) was characterized and functionally analyzed under abiotic stress conditions in T. loliiformis as well as in transgenic Nicotiana tabacum (tobacco) and Oryza sativa (rice) plants. Real-time PCR analysis on mixed elicitor cDNA libraries from T. loliiformis showed that TlOsm was upregulated a 1000-fold during the early stages of osmotic stresses (cold, drought, and salinity) in both shoots and roots but downregulated in shoots during heat stress. There was no change in TlOsm gene expression in roots of heat-stressed plants and during plant development. The plasma membrane localization of TlOsm was showed in fluorescent-tagged TlOsm tobacco plants using confocal laser scanning microscopic analysis. Transgenic rice plants expressing TlOsm were assessed for enhanced tolerance to salinity, drought and cold stresses. Constitutively expressed TlOsm in transgenic rice plants showed increased tolerance to cold, drought and salinity stress when compared with the wild-type and vector control counterparts. This was evidenced by maintained growth, retained higher water content and membrane integrity, and improved survival rate of TlOsm-expressing plants. The results thus indicate the involvement of TlOsm in plant response to multiple abiotic stresses, possibly through the signaling pathway, and highlight its potential applications for engineering crops with improved tolerance to cold, drought and salinity stress. © 2017 Scandinavian Plant Physiology Society.

  2. Aboveground Whitefly Infestation-Mediated Reshaping of the Root Microbiota

    OpenAIRE

    Kong, Hyun G.; Kim, Byung K.; Song, Geun C.; Lee, Soohyun; Ryu, Choong-Min

    2016-01-01

    Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-depend...

  3. Aboveground Whitefly Infestation-mediated Reshaping of the Root Microbiota

    OpenAIRE

    Hyun Gi Kong; Byung Kwon Kim; Geun Cheol Song; Soohyun Lee; Choong-Min Ryu

    2016-01-01

    Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. The phloem-sucking insect infestation such as whitefly and aphid on plant leaves were previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-depende...

  4. Spatio-Temporal Changes in the Rice Planting Area and Their Relationship to Climate Change in Northeast China:A Model-Based Analysis

    Institute of Scientific and Technical Information of China (English)

    XIA Tian; WU Wen-bin; ZHOU Qing-bo; YU Qiang-yi; Peter H Verburg; YANG Peng; LU Zhong-jun; TANG Hua-jun

    2014-01-01

    Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980-2010 and to analyze their relationship to climate change. To do so, the CLUE-S (conversion of land use and its effects at small region extent) model was ifrst updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods: 1980-1990, 1990-2000 and 2000-2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980-2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This conifrmed that climate change, increases in temperature in particular, greatly inlfuenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1°C isoline migration pattern, but with an obvious time-lag effect. These ifndings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC.

  5. The NS3 protein of Rice hoja blanca tenuivirus suppresses RNA silencing in plant and insect hosts by efficiently binding both siRNAs and miRNAs

    NARCIS (Netherlands)

    Hemmes, J.C.; Lakatos, L.; Goldbach, R.W.; Burgyan, J.; Prins, M.W.

    2007-01-01

    RNA silencing plays a key role in antiviral defense as well as in developmental processes in plants and insects. Negative strand RNA viruses such as the plant virus Rice hoja blanca tenuivirus (RHBV) replicate in plants and in their insect transmission vector. Like most plant-infecting viruses, RHBV

  6. The NS3 protein of Rice hoja blanca tenuivirus suppresses RNA silencing in plant and insect hosts by efficiently binding both siRNAs and miRNAs

    NARCIS (Netherlands)

    Hemmes, J.C.; Lakatos, L.; Goldbach, R.W.; Burgyan, J.; Prins, M.W.

    2007-01-01

    RNA silencing plays a key role in antiviral defense as well as in developmental processes in plants and insects. Negative strand RNA viruses such as the plant virus Rice hoja blanca tenuivirus (RHBV) replicate in plants and in their insect transmission vector. Like most plant-infecting viruses, RHBV

  7. Cognitive empathy in inter-disciplinary research: the contrasting attitudes of plant breeders and molecular biologists towards rice

    Indian Academy of Sciences (India)

    E Haribabu

    2000-12-01

    I draw attention to the perceptions of and interactions between molecular biologists and scientists engaged in plant breeding in India, who have been attempting to employ molecular biology tools to understand and intervene to improve the rice crop. The present essay suggests that the concept of cognitive empathy is crucial for enabling basic scientists and applied scientists to begin to understand phenomena from the point of view of the other and from the point of view of society at large, and in arriving at solutions that are scientifically feasible and socially acceptable. Socialization into disciplinary cultures, organizational factors and individual anxieties seem to inhibit inter-disciplinary collaboration. The majority of rice breeders and a small group of molecular biologists emphasize the relative merits of marker-assisted selection (MAS) in the near term vis-à-vis the currently controversial transgenic approach for rice crop improvement in India.

  8. Effects of Long-Term Application of Inorganic Fertilizers on Biochemical Properties of a Rice-Planting Red Soil

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wen-Hui; CAI Zu-Cong; ZHANG He

    2007-01-01

    A long-term experiment was set up in Yingtan of Jiangxi Province to investigate the effects of long-term application of inorganic fertilizers on the biochemical properties of a rice-planting soil derived from Quaternary red earth. Noncultivated soils are extremely eroded and characterized by a low pH and deficiencies in available nutrients, in particular P and N. After 13 years of inorganic fertilization in cultivation for double-cropped rice, the biochemical properties of the soil were changed. The nitrification potential and urease activity were higher in the treatments with N application than those without N application. Acid phosphatase activity and dehydrogenase activity were also higher in the treatments with P application than in those without P application. The dehydrogenase activity correlated well with the concentrations of both total P and hydrolysable N and with rice crop yield, suggesting that dehydrogenase activity might be a suitable indicator for improvement in soil fertility.

  9. Efficient generation of marker-free transgenic rice plants using an improved transposon-mediated transgene reintegration strategy.

    Science.gov (United States)

    Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong; Qu, Shaohong

    2015-01-01

    Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops.

  10. Genome-Wide Association Study for Traits Related to Plant and Grain Morphology, and Root Architecture in Temperate Rice Accessions.

    Directory of Open Access Journals (Sweden)

    Filippo Biscarini

    Full Text Available In this study we carried out a genome-wide association analysis for plant and grain morphology and root architecture in a unique panel of temperate rice accessions adapted to European pedo-climatic conditions. This is the first study to assess the association of selected phenotypic traits to specific genomic regions in the narrow genetic pool of temperate japonica. A set of 391 rice accessions were GBS-genotyped yielding-after data editing-57000 polymorphic and informative SNPS, among which 54% were in genic regions.In total, 42 significant genotype-phenotype associations were detected: 21 for plant morphology traits, 11 for grain quality traits, 10 for root architecture traits. The FDR of detected associations ranged from 3 · 10-7 to 0.92 (median: 0.25. In most cases, the significant detected associations co-localised with QTLs and candidate genes controlling the phenotypic variation of single or multiple traits. The most significant associations were those for flag leaf width on chromosome 4 (FDR = 3 · 10-7 and for plant height on chromosome 6 (FDR = 0.011.We demonstrate the effectiveness and resolution of the developed platform for high-throughput phenotyping, genotyping and GWAS in detecting major QTLs for relevant traits in rice. We identified strong associations that may be used for selection in temperate irrigated rice breeding: e.g. associations for flag leaf width, plant height, root volume and length, grain length, grain width and their ratio. Our findings pave the way to successfully exploit the narrow genetic pool of European temperate rice and to pinpoint the most relevant genetic components contributing to the adaptability and high yield of this germplasm. The generated data could be of direct use in genomic-assisted breeding strategies.

  11. SET DOMAIN GROUP701 encodes a H3K4-methytransferase and regulates multiple key processes of rice plant development.

    Science.gov (United States)

    Liu, Kunpeng; Yu, Yu; Dong, Aiwu; Shen, Wen-Hui

    2017-07-01

    Chromatin-based epigenetic information plays an important role in developmental gene regulation, in response to environment, and in natural variation of gene expression levels. Histone H3 lysine 4 di/trimethylation (H3K4me2/3) is abundant in euchromatin and is generally associated with transcriptional activation. Strikingly, however, enzymes catalyzing H3K4me2/3 remain poorly characterized in crops so far. Here, we investigated the function of the rice SET DOMAIN GROUP 701 (SDG701) gene by molecular and biochemical characterization of the gene product, and by studying effects of its loss or gain of function on plant growth and development. We demonstrated that SDG701 encodes a methytransferase specifically catalyzing H3K4 methylation. Overexpression and knockdown experiments showed that SDG701 is crucial for proper sporophytic plant development as well as for gametophytic transmission that directly impacts rice grain production. In-depth analysis of plant flowering time revealed that SDG701 promotes rice flowering under either long-day or short-day photoperiods. Consistently, the SDG701 protein was found to bind chromatin to promote H3K4me3 and to enhance expression of the rice Hd3a and RFT1 florigens. Collectively, our results establish SDG701 as a major rice H3K4-specific methyltransferase and provide important insights into function of H3K4me3 deposition in transcription activation of florigens in promoting plant flowering. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  12. Genome-Wide Association Study for Traits Related to Plant and Grain Morphology, and Root Architecture in Temperate Rice Accessions.

    Science.gov (United States)

    Biscarini, Filippo; Cozzi, Paolo; Casella, Laura; Riccardi, Paolo; Vattari, Alessandra; Orasen, Gabriele; Perrini, Rosaria; Tacconi, Gianni; Tondelli, Alessandro; Biselli, Chiara; Cattivelli, Luigi; Spindel, Jennifer; McCouch, Susan; Abbruscato, Pamela; Valé, Giampiero; Piffanelli, Pietro; Greco, Raffaella

    2016-01-01

    In this study we carried out a genome-wide association analysis for plant and grain morphology and root architecture in a unique panel of temperate rice accessions adapted to European pedo-climatic conditions. This is the first study to assess the association of selected phenotypic traits to specific genomic regions in the narrow genetic pool of temperate japonica. A set of 391 rice accessions were GBS-genotyped yielding-after data editing-57000 polymorphic and informative SNPS, among which 54% were in genic regions. In total, 42 significant genotype-phenotype associations were detected: 21 for plant morphology traits, 11 for grain quality traits, 10 for root architecture traits. The FDR of detected associations ranged from 3 · 10-7 to 0.92 (median: 0.25). In most cases, the significant detected associations co-localised with QTLs and candidate genes controlling the phenotypic variation of single or multiple traits. The most significant associations were those for flag leaf width on chromosome 4 (FDR = 3 · 10-7) and for plant height on chromosome 6 (FDR = 0.011). We demonstrate the effectiveness and resolution of the developed platform for high-throughput phenotyping, genotyping and GWAS in detecting major QTLs for relevant traits in rice. We identified strong associations that may be used for selection in temperate irrigated rice breeding: e.g. associations for flag leaf width, plant height, root volume and length, grain length, grain width and their ratio. Our findings pave the way to successfully exploit the narrow genetic pool of European temperate rice and to pinpoint the most relevant genetic components contributing to the adaptability and high yield of this germplasm. The generated data could be of direct use in genomic-assisted breeding strategies.

  13. Role of silicon in alleviation of iron deficiency and toxicity in hydroponically-grown rice (Oryza sativa L. plants

    Directory of Open Access Journals (Sweden)

    A Abdol Zadeh

    2013-03-01

    Full Text Available Silicon (Si nutrition may alleviate biotic and abiotic stresses including heavy metal deficiency and toxicity in plants. Iron deficiency and toxicity are important limiting factors in growth of rice. In the present study, role of Si nutrition on alleviation of iron deficiency and toxicity was investigated in rice plants. Plants were cultivated in greenhouse in hydroponics, using Yoshida solution, under different iron treatments (0, 2, 10, 20, 50, 100 and 250 mg/L as Fe- EDTA and Si nutrition (0 and 1.5 mM as sodium silicate. Results revealed that both iron deficiency and toxicity imposed significant reduction in fresh and dry weight and length of plants. The activity of catalase was decreased in shoots due to iron deficiency. Activity of catalase in roots and cell wall peroxidase in shoots increased under iron toxicity compared with control plants. Si nutrition increased Si content in plants and improved plant growth in both iron deficiency (not in the absence of iron and toxicity. Application of Si increased the activity of catalase in shoots and polyphenol oxidase in both roots and shoots under iron deficiency. Also, the activity of catalase in roots and polyphenol oxidase in shoots raised following iron toxicity. This in turn may reduce the oxidative stress in plants. In addition, increase of lignin in extreme iron toxicity due to Si nutrition may enhance sites of iron absorption in plant cell walls and decrease iron toxicity. The results indicated that Si nutrition could ameliorate harmful effects of iron deficiency and toxicity in rice plants possibly through improvement of antioxidant enzyme activity and reduction of oxidative stress.

  14. Overexpression of the CC-type glutaredoxin, OsGRX6 affects hormone and nitrogen status in rice plants

    Directory of Open Access Journals (Sweden)

    Ashraf eEl-Kereamy

    2015-11-01

    Full Text Available Glutaredoxins (GRXs are small glutathione dependent oxidoreductases that belong to the Thioredoxin (TRX superfamily and catalyze the reduction of disulfide bonds of their substrate proteins. Plant GRXs include three different groups based on the motif sequence, namely CPYC, CGFS and CC-type proteins. The rice CC-type proteins, OsGRX6 was identified during the screening for genes whose expression changes depending on the level of available nitrate. Overexpression of OsGRX6 in rice displayed a semi-dwarf phenotype. The OsGRX6 overexpressors contain a higher nitrogen content than the wild type, indicating that OsGRX6 plays a role in homeostatic regulation of nitrogen use. Consistent with this, OsGRX6 overexpressors displayed delayed chlorophyll degradation and senescence compared to the wild type plants. To examine if the growth defect of these transgenic lines attribute to disturbed plant hormone actions, plant hormone levels were measured. The levels of two cytokinins (CKs, 2-isopentenyladenine and trans-zeatin, and gibberellin A1 (GA1 were increased in these lines. We also found that these transgenic lines were less sensitive to exogenously applied GA, suggesting that the increase in GA1 is a result of the feedback regulation. These data suggest that OsGRX6 affects hormone signaling and nitrogen status in rice plants.

  15. In vitro Antimicrobial Assay of Actinomycetes in Rice AgainstXanthomonas oryzae pv. oryzicola and as Potential Plant Growth Promoter

    Directory of Open Access Journals (Sweden)

    Erneeza Mohd Hata

    2015-12-01

    Full Text Available ABSTRACT The aim of this work was to invitro assay the antimicrobial activity of actinomycetes in rice against Xanthomonas oryzae pv. oryzicola and as potential plant growth promoter. A total of 92 actinomycete strains were isolated from different rice plant components and field locations. Of these, only 21.74% showed antagonistic activity against the Xoc pathogen. Molecular identification via 16s rRNA amplification revealed that 60% of the active antagonistic strains belonged to the genus Streptomyces. Isolates that demonstrated the highest antagonistic activity were also able to produce hydrolytic enzymes and plant growth-promoting hormones. Combination of preliminary screening based on in vitro antagonistic, hydrolytic enzyme and plant growth hormone activity facilitated the best selection of actinomycete candidates as evidenced by strains classification using cluster analysis (Ward's Method. Results from the preliminary screening showed that actinomycetes, especially Streptomycetes, could offer a promising source for both biocontrol and plant growth-promotion agents against BLS disease in rice.

  16. Influence of sulfur on the accumulation of mercury in rice plant (Oryza sativa L.) growing in mercury contaminated soils.

    Science.gov (United States)

    Li, Yunyun; Zhao, Jiating; Guo, Jingxia; Liu, Mengjiao; Xu, Qinlei; Li, Hong; Li, Yu-Feng; Zheng, Lei; Zhang, Zhiyong; Gao, Yuxi

    2017-09-01

    Sulfur (S) is an essential element for plant growth and its biogeochemical cycling is strongly linked to the species of heavy metals in soil. In this work, the effects of S (sulfate and elemental sulfur) treatment on the accumulation, distribution and chemical forms of Hg in rice growing in Hg contaminated soil were investigated. It was found that S could promote the formation of iron plaque on the root surface and decrease total mercury (T-Hg) and methylmercury (MeHg) accumulation in rice grains, straw, and roots. Hg in the root was dominated in the form of RS-Hg-SR. Sulfate treatment increased the percentage of RS-Hg-SR to T-Hg in the rice root and changed the Hg species in soil. The dominant Hg species (70%) in soil was organic substance bound fractions. Sulfur treatment decreased Hg motility in the rhizosphere soils by promoting the conversion of RS-Hg-SR to HgS. This study is significant since it suggests that low dose sulfur treatment in Hg-containing water irrigated soil can decrease both T-Hg and MeHg accumulation in rice via inactivating Hg in the soil and promoting the formation of iron plaque in rice root, which may reduce health risk for people consuming those crops. Copyright © 2017. Published by Elsevier Ltd.

  17. Evaluation of rhizosphere, rhizoplane and phyllosphere bacteria and fungi isolated from rice in Kenya for plant growth promoters.

    Science.gov (United States)

    Mwajita, Mwashasha Rashid; Murage, Hunja; Tani, Akio; Kahangi, Esther M

    2013-01-01

    Rice (Oryza sativa L.) is the most important staple food crop in many developing countries, and is ranked third in Kenya after maize and wheat. Continuous cropping without replenishing soil nutrients is a major problem in Kenya resulting to declining soil fertility. The use of chemical fertilizers to avert the problem of low soil fertility is currently limited due to rising costs and environmental concerns. Many soil micro-organisms are able to solubilize the unavailable phosphorus, increase uptake of nitrogen and also synthesize growth promoting hormones including auxin. The aim of this study was to isolate and characterize phyllosphere, rhizoplane and rhizosphere micro-organisms from Kenyan rice with growth promoting habits. In this study whole plant rice samples were collected from different rice growing regions of Kenya. 76.2%, over 80% and 38.5% of the bacterial isolates were positive for phosphate solubilization, nitrogenase activity and IAA production whereas 17.5% and 5% of the fungal isolates were positive for phosphate solubilization and IAA production respectively. Hence these micro-organisms have potential for utilization as bio-fertilizers in rice production.

  18. Toxic tetrapyrrole accumulation in protoporphyrinogen IX oxidase-overexpressing transgenic rice plants.

    Science.gov (United States)

    Jung, Sunyo; Lee, Hye-Jung; Lee, Yonghyuk; Kang, Kiyoon; Kim, Young Soon; Grimm, Bernhard; Back, Kyoungwhan

    2008-07-01

    We generated transgenic rice plants (Oryza sativa cv. Dongjin) over-expressing human protoporphyrinogen IX oxidase (PPO) with the aim to increase mitochondrial PPO activity and confer herbicide resistance (Lee et al., Pestic Biochem Physiol 80:65-74, 2004). The transgenic plants showed during further leaf development the formation of severe necrotic spots and growth retardation. Several experiments were performed to examine the reasons for the formation of necrotic leaf lesions. Human PPO is normally located in mitochondria. An in vitro organellar import experiment revealed translocation of human PPO into pea chloroplasts, but not into mitochondria. Using a specific antibody raised against human PPO confirmed its plastidic localisation. The heme and chlorophyll contents were lower in necrotic leaves than wild-type leaves. Interestingly, mature and necrotic leaves of 12-week-old transgenic plants contained up to 14- and 24-fold more protoporphyrin IX, respectively, than mature wild-type leaves. Enhanced levels of Mg-Protoporphyrin IX, Mg-Protoporphyrin IX monomethyl ester and protochlorophyllide were concurrently observed in transgenic plants relative to wild type. Accumulated porphyrins and Mg-porphyrins likely act as photosensitizers and cause high formation of the reactive oxygen species. These high levels of tetrapyrrole intermediates correlated with increased rates of 5-aminolevulinic acid synthesis in transgenic plants. Tetrapyrrole-induced photooxidation was confirmed by increased lipid peroxidation and subsequent cell death. The transgenic phenotype is the consequence of a highly modified tetrapyrrole metabolism due to additional expression of human PPO. A possible regulatory role of PPO in graminaceous seedlings is discussed.

  19. Soil properties and olive cultivar determine the structure and diversity of plant-parasitic nematode communities infesting olive orchards soils in southern Spain.

    Directory of Open Access Journals (Sweden)

    Juan E Palomares-Rius

    Full Text Available This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into

  20. Soil Properties and Olive Cultivar Determine the Structure and Diversity of Plant-Parasitic Nematode Communities Infesting Olive Orchards Soils in Southern Spain

    Science.gov (United States)

    Palomares-Rius, Juan E.; Castillo, Pablo; Montes-Borrego, Miguel; Navas-Cortés, Juan A.; Landa, Blanca B.

    2015-01-01

    This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into consideration the specific

  1. Soil properties and olive cultivar determine the structure and diversity of plant-parasitic nematode communities infesting olive orchards soils in southern Spain.

    Science.gov (United States)

    Palomares-Rius, Juan E; Castillo, Pablo; Montes-Borrego, Miguel; Navas-Cortés, Juan A; Landa, Blanca B

    2015-01-01

    This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into consideration the specific

  2. Single-base resolution maps of cultivated and wild rice methylomes and regulatory roles of DNA methylation in plant gene expression

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    Li Xin

    2012-07-01

    Full Text Available Abstract Background DNA methylation plays important biological roles in plants and animals. To examine the rice genomic methylation landscape and assess its functional significance, we generated single-base resolution DNA methylome maps for Asian cultivated rice Oryza sativa ssp. japonica, indica and their wild relatives, Oryza rufipogon and Oryza nivara. Results The overall methylation level of rice genomes is four times higher than that of Arabidopsis. Consistent with the results reported for Arabidopsis, methylation in promoters represses gene expression while gene-body methylation generally appears to be positively associated with gene expression. Interestingly, we discovered that methylation in gene transcriptional termination regions (TTRs can significantly repress gene expression, and the effect is even stronger than that of promoter methylation. Through integrated analysis of genomic, DNA methylomic and transcriptomic differences between cultivated and wild rice, we found that primary DNA sequence divergence is the major determinant of methylational differences at the whole genome level, but DNA methylational difference alone can only account for limited gene expression variation between the cultivated and wild rice. Furthermore, we identified a number of genes with significant difference in methylation level between the wild and cultivated rice. Conclusions The single-base resolution methylomes of rice obtained in this study have not only broadened our understanding of the mechanism and function of DNA methylation in plant genomes, but also provided valuable data for future studies of rice epigenetics and the epigenetic differentiation between wild and cultivated rice.

  3. Market Impacts of Adopting Herbicide-Resistant Rice in the Southern United States

    OpenAIRE

    Fuller, Frank H.; Annou, Mamane Malam; Wailes, Eric J.

    2003-01-01

    Herbicide-resistant (HR) rice varieties offer U.S. rice producers a powerful tool for control of red rice infestations. However, improved weed control can shorten crop rotations and boost yields, resulting in expanded rice production and lower domestic market prices. Declining market returns diminish the benefits of HR rice adoption and substantially reduce net returns for nonadopters. More competitive prices increase U.S. rice exports, causing a slight decline in world rice prices. The depen...

  4. Adaptational changes in the lipids and fatty acid profile of the cell and thylakoid membrane of rice plants exposed to sunlight.

    Science.gov (United States)

    Vaz, Janet F; Sharma, Prabhat Kumar

    2010-07-01

    Adaptational changes occurring in the lipids and fatty acids of the cell and the thylakoid membrane in response to high light treatment, was studied in 30 days old rice (Oryza sativa L. cv. Jyothi) plants grown under low (150-200 μmol m(-2) s(-1)) or moderate (600-800 μmol m(-2) s(-1)) light conditions. Results were compared with rice plants grown in high (1200-2200 μmol m(-2) s(-1)) light conditions. Exposure of rice plants and isolated chloroplast to high light, resulted in an increase in the amount of malonaldehyde, indicating oxidation of membrane lipids. Qualitative and quantitative changes in the phosphoglycolipids and quantitative changes in neutral lipids were observed in rice plants grown under the different growth conditions. A few of the phosphoglycolipids and neutral lipids were present exclusively in plants grown at low or moderate or high light, indicating requirement of different type of lipid composition of rice plants in response to their different growth irradiances. However, no significant quantitative changes were observed in the different saturated and unsaturated fatty acid groups of total lipids in low, moderate and high light grown rice plants, as a result of exposure to high light. No qualitative changes in the fatty acid composition due to difference in growth irradiance or high light treatment were seen. The changes observed in the phosphoglycolipids and neutral lipid composition of cell and thylakoid membrane of low, moderate and high light grown rice plants in response to high light, are probably the result of physiological changes in the rice plants, to sustain optimum structure and function of the cell and thylakoid membrane to maintain active physiological functions to endure high light conditions.

  5. Response of rice plants to heat stress during initiation of panicle primordia or grain-filling phases

    Directory of Open Access Journals (Sweden)

    Hermann Restrepo-Diaz

    2013-08-01

    Full Text Available Leaf photosynthesis, a major determinant for yield sustainability in rice, is greatly conditioned by high temperature stress during growth. The effect of short-term high temperatures on leaf photosynthesis, stomatal conductance, Fv/Fm, SPAD readings and yield characteristics was studied in two Colombian rice cultivars. Two genotypes, cv. Fedearroz 50 (F50 and cv. Fedearroz 733 (F733 were used in pot experiments with heat stress treatment (Plants were exposed to 40°C for two and half hours for five consecutive days and natural temperature (control treatment. Heat treatments were carried out at the initiation of panicle primordial (IP or grain-filling (GF phases. The results showed that short-term high temperature stress produced a reduction on the photosynthesis rate in both cultivars either IP or GF phases. Similar trends were found on stomatal conductance in all cases due to high temperatures. Although Fv/Fm and SPAD readings were not affected by high temperatures, these variables diminished significantly among phenological phases. 'F733' rice plants showed higher number spikelet sterility due to heat stress treatments. These results seem to indicate that heat-tolerant cultivars of rice is associated with high levels of photosynthesis rate in leaves.

  6. Genome-Wide Binding Analysis of the Transcription Activator IDEAL PLANT ARCHITECTURE1 Reveals a Complex Network Regulating Rice Plant Architecture[W

    Science.gov (United States)

    Lu, Zefu; Yu, Hong; Xiong, Guosheng; Wang, Jing; Jiao, Yongqing; Liu, Guifu; Jing, Yanhui; Meng, Xiangbing; Hu, Xingming; Qian, Qian; Fu, Xiangdong; Wang, Yonghong; Li, Jiayang

    2013-01-01

    IDEAL PLANT ARCHITECTURE1 (IPA1) is critical in regulating rice (Oryza sativa) plant architecture and substantially enhances grain yield. To elucidate its molecular basis, we first confirmed IPA1 as a functional transcription activator and then identified 1067 and 2185 genes associated with IPA1 binding sites in shoot apices and young panicles, respectively, through chromatin immunoprecipitation sequencing assays. The SQUAMOSA PROMOTER BINDING PROTEIN-box direct binding core motif GTAC was highly enriched in IPA1 binding peaks; interestingly, a previously uncharacterized indirect binding motif TGGGCC/T was found to be significantly enriched through the interaction of IPA1 with proliferating cell nuclear antigen PROMOTER BINDING FACTOR1 or PROMOTER BINDING FACTOR2. Genome-wide expression profiling by RNA sequencing revealed IPA1 roles in diverse pathways. Moreover, our results demonstrated that IPA1 could directly bind to the promoter of rice TEOSINTE BRANCHED1, a negative regulator of tiller bud outgrowth, to suppress rice tillering, and directly and positively regulate DENSE AND ERECT PANICLE1, an important gene regulating panicle architecture, to influence plant height and panicle length. The elucidation of target genes of IPA1 genome-wide will contribute to understanding the molecular mechanisms underlying plant architecture and to facilitating the breeding of elite varieties with ideal plant architecture. PMID:24170127

  7. Genome-wide binding analysis of the transcription activator ideal plant architecture1 reveals a complex network regulating rice plant architecture.

    Science.gov (United States)

    Lu, Zefu; Yu, Hong; Xiong, Guosheng; Wang, Jing; Jiao, Yongqing; Liu, Guifu; Jing, Yanhui; Meng, Xiangbing; Hu, Xingming; Qian, Qian; Fu, Xiangdong; Wang, Yonghong; Li, Jiayang

    2013-10-01

    Ideal plant architecture1 (IPA1) is critical in regulating rice (Oryza sativa) plant architecture and substantially enhances grain yield. To elucidate its molecular basis, we first confirmed IPA1 as a functional transcription activator and then identified 1067 and 2185 genes associated with IPA1 binding sites in shoot apices and young panicles, respectively, through chromatin immunoprecipitation sequencing assays. The Squamosa promoter binding protein-box direct binding core motif GTAC was highly enriched in IPA1 binding peaks; interestingly, a previously uncharacterized indirect binding motif TGGGCC/T was found to be significantly enriched through the interaction of IPA1 with proliferating cell nuclear antigen promoter binding factor1 or promoter binding factor2. Genome-wide expression profiling by RNA sequencing revealed IPA1 roles in diverse pathways. Moreover, our results demonstrated that IPA1 could directly bind to the promoter of rice teosinte branched1, a negative regulator of tiller bud outgrowth, to suppress rice tillering, and directly and positively regulate dense and erect panicle1, an important gene regulating panicle architecture, to influence plant height and panicle length. The elucidation of target genes of IPA1 genome-wide will contribute to understanding the molecular mechanisms underlying plant architecture and to facilitating the breeding of elite varieties with ideal plant architecture.

  8. Micronutrient and Silicon Uptake and Removal by Upland Rice Cultivars with Different Plant Architecture

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    Carlos Alexandre Costa Crusciol

    2016-01-01

    Full Text Available ABSTRACT Upland rice cultivars manifest different nutritional demands. A field study was conducted to quantify the extraction, distribution, and removal of micronutrients and silicon by the upland rice cultivars. The experiment was arranged in a randomized complete block-split plot design. Plots consisted of three cultivars (Caiapó – traditional, BRS Primavera – intermediate, and Maravilha – modern of upland rice. Split-plots consisted of plant samplings, which occurred at 39, 46, 55, 67, 75, 83, 92, 102, 111, 118, and 125 days after emergence (DAE. Up to the end of tillering (46 DAE, all cultivars exhibited low demand for most micronutrients and Si, and took up less than 24 % of the total B, Cu, and Si, but around 31 % of the total Zn. The period of greatest uptake of micronutrients and Si occurred from 65 to 80 DAE in the Caiapó and BRS Primavera cultivars, and after 80 DAE in the Maravilha cultivar. The Caiapó and BRS Primavera cultivars took up their necessary demand of B, Mn, and Fe in the first 98 DAE and Cu, Zn, and Si up to 105 DAE, but the Maravilha cultivar took up these nutrients for two to three weeks longer. The quantities of micronutrients and Si taken up by cultivars Caiapó, BRS Primavera, and Maravilha did not exhibit large differences, and these cultivars took up between 98-135 g B, 103-110 g Cu, 1,157-1,460 g Fe, 1,278-1,424 g Mn, 240-285 g Zn, and 111-124 kg Si per hectare. The BRS Primavera cultivar showed greater removal of nutrients, with average amounts per hectare of 19.7 g B, 25.8 g Cu, 200 g Fe, 234.2 g Mn, 102.4 g Zn, and 32.6 kg Si, while the other cultivars removed smaller amounts per hectare (14.4 g B, 19.9 g Cu, 160.7 g Fe, 136.3 g Mn, 67 g Zn, and 21.9 kg Si. The BRS Primavera showed a greater removal of nutrients because it has a higher yield and allocates a greater quantity of nutrients to the panicles.

  9. Degradation Behavior of Moroxydine Hydrochloride in Rice Plant and Field Water Using High Performance Liquid Chromatography-Tandem Mass Spectrometry

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    ZHAO Lin

    2014-10-01

    Full Text Available Through field experiments, which were conducted in Zhaodong County of Heilongjiang Province, Zhulou County of Henan Province and Jurong County of Jiangsu Province, the degradation dynamics of moroxydine hydrochloride in rice plant and field water were investigated.The detection was performed by tandem mass spectrometry with electrospray ionization in positive mode(ESI+. The results showed that the average recoveries of rice plant and field water at three spiked levels (0.005, 0.05, 0.5 mg·kg -1were found in the range of 92.50%-109.20% with RSD 6.10%-6.90% and 86.40%-107.2% with RSD 0.73%-3.10%, respectively. Limits of detection(LODof plant and water were 0.005 mg·kg -1. The degradation kinetic equation showed that the half-life of moroxydine hydrochloride in rice plant and field water was 1.2-4.7 d,1.0-3.5 d, respectively. The moroxydine hydrochloride was proved to be an easily degradable pesticide.

  10. A Study on the Tritium Behavior in the Rice Plant after a Short-Term Exposure of HTO

    Energy Technology Data Exchange (ETDEWEB)

    Yook, D-S.; Lee, K. J.; Choi, Y-H.

    2002-02-26

    In many Asian countries including Korea, rice is a very important food crop. Its grain is consumed by humans and its straw is used to feed animals. In Korea, there are four CANDU type reactors that release relatively large amounts of tritium into the environment. Since 1997, KAERI (Korea Atomic Energy Research Institute) has carried out the experimental studies to obtain domestic data on various parameters concerning the direct contamination of plant. In this study, the behavior of tritium in the rice plant is predicted and compared with the measurement performed at KAERI. Using the conceptual model of the soil-plant-atmosphere tritiated water transport system which was suggested by Charles E. Murphy, tritium concentrations in the soil and in leaves to time were derived. If the effect of tritium concentration in the soil is considered, the tritium concentration in leaves is described as a double exponential model. On the other hand if the tritium concentration in the soil is disregarded, the tritium concentration in leaves is described by a single exponential term as other models (e.g. Belot's or STAR-H3 model). Also concentration of organically bound tritium in the seed is predicted and compared with measurements. The results can be used to predict the tritium concentration in the rice plant at a field around the site and the ingestion dose following the release of tritium to the environment.

  11. ISOLATION AND CHARACTERIZATION OF RHIZOBIA AND PLANT GROWTH-PROMOTING RHIZOBACTERIA AND THEIR EFFECTS ON GROWTH OF RICE SEEDLINGS

    Directory of Open Access Journals (Sweden)

    K. Z. Tan

    2014-01-01

    Full Text Available Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an alternative to reduce chemical fertilizer usage. The selection of bacterial strains with multiple beneficial characteristics are important to maximize the effectiveness on the host plant. Due to aforementioned interest, several Plant Growth-Promoting Rhizobacterial (PGPR and rhizobial strains were isolated from rice and legume roots, respectively, at four locations in Malaysia namely Universiti Putra Malaysia (UPM, Serdang, Selangor; Besut, Terengganu; Tunjung, Kelantan and Sik, Kedah. Bacterial isolations were undertaken to select the best isolates which exhibit multiple beneficial effects to the rice plant and a total of 205 bacterial strains were isolated and categorized as follows; 94 rhizospheric and 107 endophytic bacteria from rice roots, one rhizobial strain from soybean and three from Mimosa pudica. These isolates were screened for their abilities to fix N2 and solubilize phosphate; 52 were positive for both tests. The selected isolates were then tested for IAA production and other biochemical tests such as potassium solubilization, hydrolyzing enzymes (cellulase and pectinase and iron siderophore productions. Four isolates, namely UPMB19 (rhizospheric PGPR from Tunjung, Kelantan, UPMB20 (endophytic PGPR from Besut, Terengganu, UPMR30 (rhizobia from soybean and UPMR31 (rhizobia from Mimosa were selected for subsequent plant inoculation tests with UPMB10, a PGPR isolated from oil palm root, as the reference strain. Based on 16S rDNA gene sequencing, these bacterial strains were identified under several genera: Lysinibacillus, Alcaligenes, Bradyrhizobium, Rhizobium and Bacillus, respectively. Results of plant inoculation test indicated that UPMB19 significantly enhanced the seedling height at the early growth stage (7 days after transplanting, DAT which could be attributed to the higher N2

  12. Integrative Analysis of the microRNAome and Transcriptome Illuminates the Response of Susceptible Rice Plants to Rice Stripe Virus.

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    Jian Yang

    Full Text Available Rice stripe virus (RSV is one of the most serious rice viruses in East Asia. To investigate how rice responds to RSV infection, we integrated miRNA expression with parallel mRNA transcription profiling by deep sequencing. A total of 570 miRNAs were identified of which 69 miRNAs (56 up-regulated and 13 down-regulated were significantly modified by RSV infection. Digital gene expression (DGE analysis showed that 1274 mRNAs (431 up-regulated and 843 down-regulated genes were differentially expressed as a result of RSV infection. The differential expression of selected miRNAs and mRNAs was confirmed by qRT-PCR. Gene ontology (GO and pathway enrichment analysis showed that a complex set of miRNA and mRNA networks were selectively regulated by RSV infection. In particular, 63 differentially expressed miRNAs were found to be significantly and negatively correlated with 160 target mRNAs. Interestingly, 22 up-regulated miRNAs were negatively correlated with 24 down-regulated mRNAs encoding disease resistance-related proteins, indicating that the host defense responses were selectively suppressed by RSV infection. The suppression of both osa-miR1423-5p- and osa-miR1870-5p-mediated resistance pathways was further confirmed by qRT-PCR. Chloroplast functions were also targeted by RSV, especially the zeaxanthin cycle, which would affect the stability of thylakoid membranes and the biosynthesis of ABA. All these modifications may contribute to viral symptom development and provide new insights into the pathogenicity mechanisms of RSV.

  13. Unusual botfly skin infestation.

    Science.gov (United States)

    Ono, Jill C; Navin, James J; Glamb, Roman W; Hardman, John M

    2004-03-01

    Myiasis, the infestation of humans and animals with fly larvae, is observed in tropical, lowland areas. Dermatobia hominis is a common cause of cutaneous human infestation in these areas. Patients often present with a furuncular lesion on the extremities, back, or scalp. We report a case of furuncular myiasis in a patient returning from a trip to South America. We will discuss the life-cycle of D. hominis and the clinical findings important in the diagnosis of myiasis.

  14. Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals.

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    Full Text Available Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores, their parasitoids, and a dipteran species (root herbivore.We tested the hypotheses that: (1 high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2 drought stress and root herbivory change the profile of volatile organic chemicals (VOCs emitted by the host plant; (3 parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference, plant volatile emissions, parasitism success (performance, and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40-55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial

  15. Identification of QTLs for Plant Height and Its Components by Using Single Segment Substitution Lines in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    HE Feng-hua; XI Zhang-ying; ZENG Rui-zhen; Akshay TALUKDAR; ZHANG Gui-quan

    2005-01-01

    QTLs for plant height and its components on the substituted segments of fifty-two single segment substitution lines (SSSLs)in rice were identified through t-test (P≤0.001) for comparison between each SSSL and recipient parent Huajingxian 74. On the 14 substituted segments, 24 QTLs were detected, 10 for plant height, 2 for panicle length, 4 for length of thefirst internode from the top,5 for length of the second internode from the top and 3 for length of the third internode from the top, respectively. All these QTLs were distributed on nine rice chromosomes except chromosomes 5, 9 and 11. The additive effect ranged from -4.08 to 3.98 cm, and the additive effect percentages varied from -19.35% to 10.43%.

  16. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants.

    Science.gov (United States)

    Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants have generally been developed using genes encoding proteins that control drought regulatory networks. These proteins include transcription factors, protein kinases, receptor-like kinases, enzymes related to osmoprotectant or plant hormone synthesis, and other regulatory or functional proteins. Of the drought-tolerant transgenic rice plants described in this review, approximately one-third show decreased plant height under non-stressed conditions or in response to abscisic acid treatment. In cereal crops, plant height is a very important agronomic trait directly affecting yield, although the improvement of lodging resistance should also be taken into consideration. Understanding the regulatory mechanisms of plant growth reduction under drought stress conditions holds promise for developing transgenic plants that produce high yields under drought stress conditions. Plant growth rates are reduced more rapidly than photosynthetic activity under drought conditions, implying that plants actively reduce growth in response to drought stress. In this review, we summarize studies on molecular regulatory networks involved in response to drought stress. In a separate section, we highlight progress in the development of transgenic drought-tolerant rice plants, with special attention paid to field trial investigations.

  17. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    Directory of Open Access Journals (Sweden)

    Daisuke eTodaka

    2015-02-01

    Full Text Available Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants have generally been developed using genes encoding proteins that control drought regulatory networks. These proteins include transcription factors, protein kinases, receptor-like kinases, enzymes related to osmoprotectant or plant hormone synthesis, and other regulatory or functional proteins. Of the drought-tolerant transgenic rice plants described in this review, approximately one-third show decreased plant height under non-stressed conditions or in response to abscisic acid treatment. In cereal crops, plant height is a very important agronomic trait directly affecting yield, although the improvement of lodging resistance should also be taken into consideration. Understanding the regulatory mechanisms of plant growth reduction under drought stress conditions holds promise for developing transgenic plants that produce high yields under drought stress conditions. Plant growth rates are reduced more rapidly than photosynthetic activity under drought conditions, implying that plants actively reduce growth in response to drought stress. In this review, we summarize studies on molecular regulatory networks involved in response to drought stress. In a separate section, we highlight progress in the development of transgenic drought-tolerant rice plants, with special attention paid to field trial investigations.

  18. The importance of Nyando river wetlands plant resources and agricultural products: A comparative study of papyrus and rice.

    OpenAIRE

    Omollow, Maurice Omondi

    2003-01-01

    This study assessed the community perceptions of the importance of wetland plants, particularly papyrus ( Cyperus papyrus) and compared it with that of agricultural products, mainly rice ( Oryza Sativa ), in the Nyando River Wetlands, Kenya. The goal was to suggest better mechanisms for the sustainable management of the two resources and the wetlands. It was conducted among communities living in NRW area namely Nyando, Lower Nyakach and Kadibo Divisions of Kisumu and Ny ando districts, from A...

  19. Ni2+ toxicity in rice: effect on membrane functionality and plant water content.

    Science.gov (United States)

    Llamas, Andreu; Ullrich, Cornelia I; Sanz, Amparo

    2008-10-01

    The heavy metal nickel is an essential mineral trace nutrient found at low concentrations in most natural soils. However, it may reach toxic levels in certain areas and affect a number of biochemical and physiological processes in plants. Wilting and leaf necrosis have been described as typical visible symptoms of Ni(2+) toxicity. The plasma membrane (PM) of root cells constitutes the first barrier for the entry of heavy metals but also a target of their toxic action. This work studies the relationship between disturbances of membrane functionality and the development of the typical symptoms of Ni(2+) toxicity. Rice plants (Oryza sativa L. cv. Bahia) grown in nutrient medium containing 0.5mM Ni(2+) showed a significant decrease in water content as a consequence of the stress. Addition of Ni(2+) to the solution bathing the roots induced a concentration-dependent PM depolarization but the activity of the PM-H(+)-ATPase was not inhibited by the presence of Ni(2+) and the initial resting potential recovered in less than 1h. In the short term (hours), membrane permeability of root cells was not significantly affected by Ni(2+) treatments. However, in the long term (days) a drastic loss of K(+) was measured in roots and shoots, which should be responsible for the changes in the water content measured, since stomatal conductance and the transpiration rate remained unaffected by Ni(2+) treatment. The effects induced by Ni(2+) were not permanent and could be reverted, at least in part, by transferring the plants to a medium without Ni(2+).

  20. Virus-mediated chemical changes in rice plants impact the relationship between non-vector planthopper Nilaparvata lugens Stål and its egg parasitoid Anagrus nilaparvatae Pang et Wang.

    Science.gov (United States)

    He, Xiaochan; Xu, Hongxing; Gao, Guanchun; Zhou, Xiaojun; Zheng, Xusong; Sun, Yujian; Yang, Yajun; Tian, Junce; Lu, Zhongxian

    2014-01-01

    In order to clarify the impacts of southern rice black-streaked dwarf virus (SRBSDV) infection on rice plants, rice planthoppers and natural enemies, differences in nutrients and volatile secondary metabolites between infected and healthy rice plants were examined. Furthermore, the impacts of virus-mediated changes in plants on the population growth of non-vector brown planthopper (BPH), Nilaparvata lugens, and the selectivity and parasitic capability of planthopper egg parasitoid Anagrus nilaparvatae were studied. The results showed that rice plants had no significant changes in amino acid and soluble sugar contents after SRBSDV infection, and SRBSDV-infected plants had no significant effect on population growth of non-vector BPH. A. nilaparvatae preferred BPH eggs both in infected and healthy rice plants, and tended to parasitize eggs on infected plants, but it had no significant preference for infected plants or healthy plants. GC-MS analysis showed that tridecylic aldehyde occurred only in rice plants infected with SRBSDV, whereas octanal, undecane, methyl salicylate and hexadecane occurred only in healthy rice plants. However, in tests of behavioral responses to these five volatile substances using a Y-tube olfactometer, A. nilaparvatae did not show obvious selectivity between single volatile substances at different concentrations and liquid paraffin in the control group. The parasitic capability of A. nilaparvatae did not differ between SRBSDV-infected plants and healthy plant seedlings. The results suggested that SRBSDV-infected plants have no significant impacts on the non-vector planthopper and its egg parasitoid, A. nilaparvatae.

  1. Mapping paddy rice planting area in cold temperate climate region through analysis of time series Landsat 8 (OLI), Landsat 7 (ETM+) and MODIS imagery

    Science.gov (United States)

    Qin, Yuanwei; Xiao, Xiangming; Dong, Jinwei; Zhou, Yuting; Zhu, Zhe; Zhang, Geli; Du, Guoming; Jin, Cui; Kou, Weili; Wang, Jie; Li, Xiangping

    2015-07-01

    Accurate and timely rice paddy field maps with a fine spatial resolution would greatly improve our understanding of the effects of paddy rice agriculture on greenhouse gases emissions, food and water security, and human health. Rice paddy field maps were developed using optical images with high temporal resolution and coarse spatial resolution (e.g., Moderate Resolution Imaging Spectroradiometer (MODIS)) or low temporal resolution and high spatial resolution (e.g., Landsat TM/ETM+). In the past, the accuracy and efficiency for rice paddy field mapping at fine spatial resolutions were limited by the poor data availability and image-based algorithms. In this paper, time series MODIS and Landsat ETM+/OLI images, and the pixel- and phenology-based algorithm are used to map paddy rice planting area. The unique physical features of rice paddy fields during the flooding/open-canopy period are captured with the dynamics of vegetation indices, which are then used to identify rice paddy fields. The algorithm is tested in the Sanjiang Plain (path/row 114/27) in China in 2013. The overall accuracy of the resulted map of paddy rice planting area generated by both Landsat ETM+ and OLI is 97.3%, when evaluated with areas of interest (AOIs) derived from geo-referenced field photos. The paddy rice planting area map also agrees reasonably well with the official statistics at the level of state farms (R2 = 0.94). These results demonstrate that the combination of fine spatial resolution images and the phenology-based algorithm can provide a simple, robust, and automated approach to map the distribution of paddy rice agriculture in a year.

  2. Mapping paddy rice planting area in cold temperate climate region through analysis of time series Landsat 8 (OLI), Landsat 7 (ETM+) and MODIS imagery.

    Science.gov (United States)

    Qin, Yuanwei; Xiao, Xiangming; Dong, Jinwei; Zhou, Yuting; Zhu, Zhe; Zhang, Geli; Du, Guoming; Jin, Cui; Kou, Weili; Wang, Jie; Li, Xiangping

    2015-07-01

    Accurate and timely rice paddy field maps with a fine spatial resolution would greatly improve our understanding of the effects of paddy rice agriculture on greenhouse gases emissions, food and water security, and human health. Rice paddy field maps were developed using optical images with high temporal resolution and coarse spatial resolution (e.g., Moderate Resolution Imaging Spectroradiometer (MODIS)) or low temporal resolution and high spatial resolution (e.g., Landsat TM/ETM+). In the past, the accuracy and efficiency for rice paddy field mapping at fine spatial resolutions were limited by the poor data availability and image-based algorithms. In this paper, time series MODIS and Landsat ETM+/OLI images, and the pixel- and phenology-based algorithm are used to map paddy rice planting area. The unique physical features of rice paddy fields during the flooding/open-canopy period are captured with the dynamics of vegetation indices, which are then used to identify rice paddy fields. The algorithm is tested in the Sanjiang Plain (path/row 114/27) in China in 2013. The overall accuracy of the resulted map of paddy rice planting area generated by both Landsat ETM+ and OLI is 97.3%, when evaluated with areas of interest (AOIs) derived from geo-referenced field photos. The paddy rice planting area map also agrees reasonably well with the official statistics at the level of state farms (R(2) = 0.94). These results demonstrate that the combination of fine spatial resolution images and the phenology-based algorithm can provide a simple, robust, and automated approach to map the distribution of paddy rice agriculture in a year.

  3. Special rice in China

    Institute of Scientific and Technical Information of China (English)

    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

  4. Design and Test on Sowing Device of the Multi-functional Machine for Rice-wheat Cyclic Planting

    Directory of Open Access Journals (Sweden)

    Yulun Chen

    2015-02-01

    Full Text Available In order to effectively eliminate the disadvantages of improper disposing of residues and fully exploit the advantages of no-tillage seed drill technology, a machine for rice-wheat cyclic planting was developed by designing and attaching drilling and ditching assembly to a combine harvesting assembly. Tests carried out on drilling practice showed that, multi-functional machine for rice-wheat rotation, rubber track was adopted to substitute the traditional land wheel for drilling driving, cannot only effectively get rid of the intermittent drilling, but also can easily achieve the speed synchronization of harvesting and sowing practice; within the limitation of designed walking velocity, mean values of the row consistency and stability of seeding quantity as well as seeding uniformity were 93.9±1.4%, 98.4±0.5% and 76.2±5.3% respectively, which could meet the performance requirement of rice direct seeding with soil cover; for a suitable broken rate, the working length of the fluted roller is preferred to be not less than 9.4 mm if NJ210-80 roller feed was chosen to drill rice, the transmission ratio can be increased to reduce the rotary speed of the fluted roller to acquire a suitable seeding quantity, if the value exceeds the agronomic requirement of the local seeding date.

  5. Aboveground Whitefly Infestation-mediated Reshaping of the Root Microbiota

    Directory of Open Access Journals (Sweden)

    Hyun Gi Kong

    2016-09-01

    Full Text Available Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. The phloem-sucking insect infestation such as whitefly and aphid on plant leaves were previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1–V3 region by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation and confirmed the recruitment of fluorescent Pseudomonas spp. exhibiting the insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly-infested plant rhizosphere. Our results indicate that whitefly infestation leads plant recruiting specific group of rhizosphere bacteria conferring beneficial traits for host plant. This study provides a new

  6. Aboveground Whitefly Infestation-Mediated Reshaping of the Root Microbiota

    Science.gov (United States)

    Kong, Hyun G.; Kim, Byung K.; Song, Geun C.; Lee, Soohyun; Ryu, Choong-Min

    2016-01-01

    Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1–V3 region) by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation, and the fluorescent Pseudomonas spp. recruited to the rhizosphere were confirmed to exhibit insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly infested plant rhizosphere. Our results indicate that whitefly infestation leads to the recruitment of specific groups of rhizosphere bacteria by the plant, which confer beneficial traits to the host plant. This

  7. Plant growth-promoting bacteria Bacillus amyloliquefaciens NBRISN13 modulates gene expression profile of leaf and rhizosphere community in rice during salt stress.

    Science.gov (United States)

    Nautiyal, Chandra Shekhar; Srivastava, Suchi; Chauhan, Puneet Singh; Seem, Karishma; Mishra, Aradhana; Sopory, Sudhir Kumar

    2013-05-01

    Growth and productivity of rice and soil inhabiting microbial population is negatively affected by soil salinity. However, some salt resistant, rhizosphere competent bacteria improve plant health in saline stress. Present study evaluated the effect of salt tolerant Bacillus amyloliquefaciens NBRISN13 (SN13) inoculation on rice plants in hydroponic and soil conditions exposed to salinity. SN13 increased plant growth and salt tolerance (NaCl 200 mM) and expression of at least 14 genes under hydroponic and soil conditions in rice. Among these 14 genes 4 (NADP-Me2, EREBP, SOSI, BADH and SERK1) were up-regulated and 2 (GIG and SAPK4) repressed under salt stress in hydroponic condition. In greenhouse experiment, salt stress resulted in accumulation of MAPK5 and down-regulation of the remaining 13 transcripts was observed. SN13 treatment, with or without salt gave similar expression for all tested genes as compared to control. Salt stress caused changes in the microbial diversity of the rice rhizosphere and stimulated population of betaine-, sucrose-, trehalose-, and glutamine-utilizing bacteria in salt-treated rice rhizosphere (SN13 + salt). The observations imply that SN13 confers salt tolerance in rice by modulating differential transcription in a set of at least 14 genes. Stimulation of osmoprotectant utilizing microbial population as a mechanism of inducing salt tolerance in rice is reported for the first time in this study to the best of our knowledge.

  8. Transcriptional profiling of the PDR gene family in rice roots in response to plant growth regulators, redox perturbations and weak organic acid stresses.

    Science.gov (United States)

    Moons, Ann

    2008-12-01

    The role of plant pleiotropic drug resistance (PDR) type ATP-binding cassette (ABC) transporters remains poorly understood. We characterized the expression of the rice pleiotropic drug resistance (PDR) gene family in roots, where PDR transporters are believed to have major functions. A prototypical oligonucleotide array was developed containing 70-mers chosen in the gene-specific 3' untranslated regions of the rice PDR genes, other full-molecule rice ABC transporter genes and relevant marker genes. Jasmonates, which are involved in plant defense and secondary metabolism, proved major inducers of PDR gene expression. Over half of the PDR genes were JA-induced in roots of rice; OsPDR9 to the highest level. Salicylic acid, involved in plant pathogen defense, markedly induced the expression of OsPDR20. OsPDR20 was cDNA cloned and characterized. Abscisic acid, typically involved in water deficit responses, particularly induced OsPDR3 in roots and shoot and OsPDR6 in rice leaves. OsPDR9 and OsPDR20 were furthermore up-regulated in response to dithiothreitol- or glutathione-induced redox perturbations. Exogenous application of the weak organic acids lactic acid, malic acid, and citric acid differentially induced the expression of OsPDR3, OsPDR8, OsPDR9 and OsPDR20 in rice seedling roots. This transcriptional survey represents a guide for the further functional analysis of individual PDR transporters in roots of rice.

  9. Transgenic Expression of a Functional Fragment of Harpin Protein Hpa1 in Wheat Represses English Grain Aphid Infestation

    Institute of Scientific and Technical Information of China (English)

    XU Man-yu; ZHOU Ting; ZHAO Yan-ying; LI Jia-bao; XU Heng; DONG Han-song; ZHANG Chun-ling

    2014-01-01

    The harpin protein Hpa1 produced by the rice bacterial blight pathogen promotes plant growth and induces plant resistance to pathogens and insect pests. The region of 10-42 residues (Hpa110-42) in the Hpa1 sequence is critical as the isolated Hpa110-42 fragment is 1.3-7.5-fold more effective than the full length in inducing plant growth and resistance. Here we report that transgenic expression of Hpa110-42 in wheat induces resistance to English grain aphid, a dominant species of wheat aphids. Hpa110-42-induced resistance is effective to inhibit the aphid behavior in plant preference at the initial colonization stage and repress aphid performances in the reproduction, nymph growth, and instar development on transgenic plants. The resistance characters are correlated with enhanced expression of defense-regulatory genes (EIN2, PP2-A, and GSL10) and consistent with induced expression of defense response genes (Hel, PDF1.2, PR-1b, and PR-2b). As a result, aphid infestations are alleviated in transgenic plants. The level of Hpa110-42-induced resistance in regard to repression of aphid infestations is equivalent to the effect of chemical control provided by an insecticide. These results suggested that the defensive role of Hpa110-42 can be integrated into breeding germplasm of the agriculturally signiifcant crop with a great potential of the agricultural application.

  10. Arbuscular mycorrhizal symbiosis ameliorates the optimum quantum yield of photosystem II and reduces non-photochemical quenching in rice plants subjected to salt stress.

    Science.gov (United States)

    Porcel, Rosa; Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Aroca, Ricardo; Garcia, Rosalva; Ruiz-Lozano, Juan Manuel

    2015-08-01

    Rice is the most important food crop in the world and is a primary source of food for more than half of the world population. However, salinity is considered the most common abiotic stress reducing its productivity. Soil salinity inhibits photosynthetic processes, which can induce an over-reduction of the reaction centres in photosystem II (PSII), damaging the photosynthetic machinery. The arbuscular mycorrhizal (AM) symbiosis may improve host plant tolerance to salinity, but it is not clear how the AM symbiosis affects the plant photosynthetic capacity, particularly the efficiency of PSII. This study aimed at determining the influence of the AM symbiosis on the performance of PSII in rice plants subjected to salinity. Photosynthetic activity, plant gas-exchange parameters, accumulation of photosynthetic pigments and rubisco activity and gene expression were also measured in order to analyse comprehensively the response of the photosynthetic processes to AM symbiosis and salinity. Results showed that the AM symbiosis enhanced the actual quantum yield of PSII photochemistry and reduced the quantum yield of non-photochemical quenching in rice plants subjected to salinity. AM rice plants maintained higher net photosynthetic rate, stomatal conductance and transpiration rate than nonAM plants. Thus, we propose that AM rice plants had a higher photochemical efficiency for CO2 fixation and solar energy utilization and this increases plant salt tolerance by preventing the injury to the photosystems reaction centres and by allowing a better utilization of light energy in photochemical processes. All these processes translated into higher photosynthetic and rubisco activities in AM rice plants and improved plant biomass production under salinity.

  11. Gibberellin homeostasis and plant height control by EUI and a role for gibberellin in root gravity responses in rice

    Institute of Scientific and Technical Information of China (English)

    Yingying Zhang; Yongyou Zhu; Yu Peng; Dawei Yan; Qun Li; Jianjun Wang; Linyou Wang; Zuhua He

    2008-01-01

    The rice Eui (ELONGATED UPPERMOST MTERNODE) gene encodes a cytochrome P450 monooxygenase that deactivates bioactive gibberellins (GAs). In this study, we investigated controlled expression of the Eui gene and its role in plant development. We found that Eui was differentially induced by exogenous GAs and that the Eui promoter had the highest activity in the vascular bundles. The eui mutant was defective in starch granule development in root caps and Eui overexpression enhanced starch granule generation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Experiments using embryoless half-seeds revealed that RAmy lA and GAmyb were highly upregulated in eui aleurone cells in the absence of exogenous GA. In addition, the GA biosynthesis genes GA3oxl and GA20ox2 were downregulated and GA2oxl was upregulated in eui seedlings. These results indicate that EUI is involved in GA homeostasis, not only in the internodes at the heading stage, but also in the seedling stage, roots and seeds. Disturbing GA homeostasis affected the expression of the GA signaling genes GID1 (GIBBERELLIN INSENSITIVE DWARF 1), GID2 and SLR1. Transgenic RNA interference of the Eui gene effectively increased plant height and improved heading performance. By contrast, the ectopic expression of Eui under the promoters of the rice GA biosynthesis genes GA3ox2 and GA20ox2 significantly reduced plant height. These results demonstrate that a slight increase in Eui expression could dramatically change rice morphology, indicating the practical application of the Eui gene in rice molecular breeding for a high yield potential.

  12. Performance evaluation of various classifiers for color prediction of rice paddy plant leaf

    Science.gov (United States)

    Singh, Amandeep; Singh, Maninder Lal

    2016-11-01

    The food industry is one of the industries that uses machine vision for a nondestructive quality evaluation of the produce. These quality measuring systems and softwares are precalculated on the basis of various image-processing algorithms which generally use a particular type of classifier. These classifiers play a vital role in making the algorithms so intelligent that it can contribute its best while performing the said quality evaluations by translating the human perception into machine vision and hence machine learning. The crop of interest is rice, and the color of this crop indicates the health status of the plant. An enormous number of classifiers are available to solve the purpose of color prediction, but choosing the best among them is the focus of this paper. Performance of a total of 60 classifiers has been analyzed from the application point of view, and the results have been discussed. The motivation comes from the idea of providing a set of classifiers with excellent performance and implementing them on a single algorithm for the improvement of machine vision learning and, hence, associated applications.

  13. Translocation and biotransformation of CuO nanoparticles in rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Peng, Cheng; Duan, Dechao; Xu, Chen; Chen, Yongsheng; Sun, Lijuan; Zhang, Hai; Yuan, Xiaofeng; Zheng, Lirong; Yang, Yuanqiang; Yang, Jianjun; Zhen, Xiangjun; Chen, Yingxu; Shi, Jiyan

    2015-02-01

    Metal-based nanoparticles (MNPs) may be translocated and biochemically modified in vivo, which may influence the fate of MNPs in the environment. Here, synchrotron-based techniques were used to investigate the behavior of CuO NPs in rice plants exposed to 100 mg/L CuO NPs for 14 days. Micro X-ray fluorescence (μ-XRF) and micro X-ray absorption near edge structure (μ-XANES) analysis revealed that CuO NPs moved into the root epidermis, exodermis, and cortex, and they ultimately reached the endodermis but could not easily pass the Casparian strip; however, the formation of lateral roots provided a potential pathway for MNPs to enter the stele. Moreover, bulk-XANES data showed that CuO NPs were transported from the roots to the leaves, and that Cu (II) combined with cysteine, citrate, and phosphate ligands and was even reduced to Cu (I). CuO NPs and Cu-citrate were observed in the root cells using soft X-ray scanning transmission microscopy (STXM).

  14. Microbial Community Analysis of Anodes from Sediment Microbial Fuel Cells Powered by Rhizodeposits of Living Rice Plants ▿ †

    Science.gov (United States)

    De Schamphelaire, Liesje; Cabezas, Angela; Marzorati, Massimo; Friedrich, Michael W.; Boon, Nico; Verstraete, Willy

    2010-01-01

    By placing the anode of a sediment microbial fuel cell (SMFC) in the rhizosphere of a rice plant, root-excreted rhizodeposits can be microbially oxidized with concomitant current generation. Here, various molecular techniques were used to characterize the composition of bacterial and archaeal communities on such anodes, as influenced by electrical circuitry, sediment matrix, and the presence of plants. Closed-circuit anodes in potting soil were enriched with Desulfobulbus-like species, members of the family Geobacteraceae, and as yet uncultured representatives of the domain Archaea. PMID:20097806

  15. The ability on hydraulic-lift from deeper rooted plants with a phytoassay of rice (Oryza sativa L.)

    OpenAIRE

    2009-01-01

    Hydraulic lift(HL), the exudation of water from root system of deeper rooted plants under soil desiccated conditions is considered as a potential irrigation system in drought areas. The ability of HL in sorghum(Sorghum bicolor(L.)Moench)was evaluated by a split root experiment with mixed-cropped rice(Oryza sativa L.)as an indicator plant for phytoassay. Growth parameters of rice and soil water conditions are measured after withholding irrigation with or without sorghum root connection between...

  16. Developing selection protocols for weed competitiveness in aerobic rice

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Aerobic rice production systems, wherein rice is dry-sown in non-puddled soil and grown as an upland crop, offer large water savings but are subject to severe weed infestation. Weed-competitive cultivars will be critical to the adoption of aerobic rice production by farmers. Breeding

  17. Transgenic rice plants expressing the snowdrop lectin gene (gna) exhibit high-level resistance to the whitebacked planthopper (Sogatella furcifera).

    Science.gov (United States)

    Nagadhara, D; Ramesh, S; Pasalu, I C; Rao, Y Kondala; Sarma, N P; Reddy, V D; Rao, K V

    2004-11-01

    Transgenic rice plants, expressing snowdrop lectin [Galanthus nivalis agglutinin (GNA)], obtained by Agrobacterium-mediated genetic transformation, were evaluated for resistance against the insect, the whitebacked planthopper (WBPH). The transgene gna was driven by the phloem-specific, rice-sucrose synthase promoter RSs1, and the bar was driven by the CaMV 35S promoter. In our previous study, the transgenic status of these lines was confirmed by Southern, Northern and Western blot analyses. Both the transgenes, gna and bar, were stably inherited and co-segregated into progenies in T1 to T5 generations. Insect bioassays on transgenic plants revealed the potent entomotoxic effects of GNA on the WBPH. Also, significant decreases were observed in the survival, development and fecundity of the insects fed on transgenic plants. Furthermore, intact GNA was detected in the total proteins of WBPHs fed on these plants. Western blot analysis revealed stable and consistent expression of GNA throughout the growth and development of transgenic plants. Transgenic lines expressing GNA exhibited high-level resistance against the WBPH. As reported earlier, these transgenics also showed substantial resistance against the brown planthopper and green leafhopper.

  18. Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae

    Directory of Open Access Journals (Sweden)

    Wiler Ribas Moreira

    2015-08-01

    Full Text Available Brown spot (BS, caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L. plants (cv. Metica-1 grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids, were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.

  19. Effect of Different Planting Dates on the Panicle Characteristics and Yield of Rice Cultivars in Northern Khuzestan

    Directory of Open Access Journals (Sweden)

    K. Limoochi

    2015-03-01

    Full Text Available This study aimed at evaluating the effect of different planting dates (different ambient temperature conditions on the characteristics of rice panicle and yield of its cultivars in Khuzestan climate in 2010. The experimental design was a split plot in a Randomized Block Design with four replications. The main factor was the planting date with three dates (May 25th , June 9th , and June 25th and the sub factor consisted of three rice cultivars including Red Anbori (long and short, and Champa. Results showed that the highest grain yield, seed weight in each panicle, grain number, and 1000-grain weight belonged to the third planting date the highest fertility percentage belonged to the second planting date and the highest number of unfilled seeds in panicle and weight of unfilled 1000-grain were observed in the first planting date. With an average of 3795.4 Kg/ ha, Champa cultivar had the highest grain yield. In addition, given the correlation coefficients, grain yield had the most positive and significant correlations with 1000-grain weight (0.779*, weight of each panicle`s seeds (0.755*, and the number of filled seeds per panicle (0.403*, which indicates the high and direct impact of these characteristics on the increase of yield as well as the necessity of conducting further studies to increase the yield.

  20. Cytosolic APX knockdown rice plants sustain photosynthesis by regulation of protein expression related to photochemistry, Calvin cycle and photorespiration.

    Science.gov (United States)

    Carvalho, Fabrício E L; Ribeiro, Carolina W; Martins, Márcio O; Bonifacio, Aurenivia; Staats, Charley C; Andrade, Cláudia M B; Cerqueira, João V; Margis-Pinheiro, Márcia; Silveira, Joaquim A G

    2014-04-01

    The biochemical mechanisms underlying the involvement of cytosolic ascorbate peroxidases (cAPXs) in photosynthesis are still unknown. In this study, rice plants doubly silenced in these genes (APX1/2) were exposed to moderate light (ML) and high light (HL) to assess the role of cAPXs in photosynthetic efficiency. APX1/2 mutants that were exposed to ML overexpressed seven and five proteins involved in photochemical activity and photorespiration, respectively. These plants also increased the pheophytin and chlorophyll levels, but the amount of five proteins that are important for Calvin cycle did not change. These responses in mutants were associated with Rubisco carboxylation rate, photosystem II (PSII) activity and potential photosynthesis, which were similar to non-transformed plants. The upregulation of photochemical proteins may be part of a compensatory mechanism for APX1/2 deficiency but apparently the finer-control for photosynthesis efficiency is dependent on Calvin cycle proteins. Conversely, under HL the mutants employed a different strategy, triggering downregulation of proteins related to photochemical activity, Calvin cycle and decreasing the levels of photosynthetic pigments. These changes were associated to strong impairment in PSII activity and Rubisco carboxylation. The upregulation of some photorespiratory proteins was maintained under that stressful condition and this response may have contributed to photoprotection in rice plants deficient in cAPXs. The data reveal that the two cAPXs are not essential for photosynthesis in rice or, alternatively, the deficient plants are able to trigger compensatory mechanisms to photosynthetic acclimation under ML and HL conditions. These mechanisms involve differential regulation in protein expression related to photochemistry, Calvin cycle and photorespiration.

  1. Two independent S-phase checkpoints regulate appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae

    Science.gov (United States)

    Osés-Ruiz, Míriam; Sakulkoo, Wasin; Littlejohn, George R.; Martin-Urdiroz, Magdalena

    2017-01-01

    To cause rice blast disease, the fungal pathogen Magnaporthe oryzae develops a specialized infection structure called an appressorium. This dome-shaped, melanin-pigmented cell generates enormous turgor and applies physical force to rupture the rice leaf cuticle using a rigid penetration peg. Appressorium-mediated infection requires septin-dependent reorientation of the F-actin cytoskeleton at the base of the infection cell, which organizes polarity determinants necessary for plant cell invasion. Here, we show that plant infection by M. oryzae requires two independent S-phase cell-cycle checkpoints. Initial formation of appressoria on the rice leaf surface requires an S-phase checkpoint that acts through the DNA damage response (DDR) pathway, involving the Cds1 kinase. By contrast, appressorium repolarization involves a novel, DDR-independent S-phase checkpoint, triggered by appressorium turgor generation and melanization. This second checkpoint specifically regulates septin-dependent, NADPH oxidase-regulated F-actin dynamics to organize the appressorium pore and facilitate entry of the fungus into host tissue. PMID:28028232

  2. The Phase-Formation Behavior of Composite Ceramic Powders Synthesized by Utilizing Rice Husk Ash from the Biomass Cogeneration Plant

    Directory of Open Access Journals (Sweden)

    Wenjie Yuan

    2015-01-01

    Full Text Available The development and utilization of biomass as a vital source of renewable energy were stimulated in order to reduce the global dependency on fossil fuels. A lot of rice husk ashes (RHA were generated as the waste after the rice husk as the main fuel was burnt in the biomass cogeneration plant. The phase-formation behavior of composite ceramic powders synthesized by using rice husk ash from the biomass cogeneration plant at the different carbon ratios and temperatures was investigated. The sequence of phase formation with the calcining temperatures ranging from 1773 K to 1853 K was followed by O′-Sialon→SiC + Si3N4→SiC in samples with C/SiO2  =  1 : 1–4 : 1. Ca-α-Sialon formed in samples with C/SiO2  =  5 : 1 and 6 : 1. The results highlighted that series of reactions happening sensitively depended on C/SiO2 and the temperature and demonstrated that the carbothermal nitridation provided an alternative for converting RHA waste into composite ceramic powders.

  3. Estimation of the age and amount of brown rice plant hoppers based on bionic electronic nose use.

    Science.gov (United States)

    Xu, Sai; Zhou, Zhiyan; Lu, Huazhong; Luo, Xiwen; Lan, Yubin; Zhang, Yang; Li, Yanfang

    2014-09-29

    The brown rice plant hopper (BRPH), Nilaparvata lugens (Stal), is one of the most important insect pests affecting rice and causes serious damage to the yield and quality of rice plants in Asia. This study used bionic electronic nose technology to sample BRPH volatiles, which vary in age and amount. Principal component analysis (PCA), linear discrimination analysis (LDA), probabilistic neural network (PNN), BP neural network (BPNN) and loading analysis (Loadings) techniques were used to analyze the sampling data. The results indicate that the PCA and LDA classification ability is poor, but the LDA classification displays superior performance relative to PCA. When a PNN was used to evaluate the BRPH age and amount, the classification rates of the training set were 100% and 96.67%, respectively, and the classification rates of the test set were 90.67% and 64.67%, respectively. When BPNN was used for the evaluation of the BRPH age and amount, the classification accuracies of the training set were 100% and 48.93%, respectively, and the classification accuracies of the test set were 96.67% and 47.33%, respectively. Loadings for BRPH volatiles indicate that the main elements of BRPHs' volatiles are sulfur-containing organics, aromatics, sulfur-and chlorine-containing organics and nitrogen oxides, which provide a reference for sensors chosen when exploited in specialized BRPH identification devices. This research proves the feasibility and broad application prospects of bionic electronic noses for BRPH recognition.

  4. The local impact of a coal-fired power plant on inorganic mercury and methyl-mercury distribution in rice (Oryza sativa L.).

    Science.gov (United States)

    Xu, Xiaohang; Meng, Bo; Zhang, Chao; Feng, Xinbin; Gu, Chunhao; Guo, Jianyang; Bishop, Kevin; Xu, Zhidong; Zhang, Sensen; Qiu, Guangle

    2017-04-01

    Emission from coal-fired power plants is one of the major anthropogenic sources of mercury (Hg) in the environment, because emitted Hg can be quickly deposited nearby the source, attention is paid to the effects of coal-burning facilities on levels of toxic methyl-mercury (MeHg) in biota near such sources. Since rice is an agricultural crop that can bio-accumulate MeHg, the potential effects of a large Hg-emitting coal-fired power plant in Hunan Province, China on both inorganic Hg (Hg(II)) and MeHg distributions in rice was investigated. Relatively high MeHg (up to 3.8 μg kg(-1)) and Hg(II) (up to 22 μg kg(-1)) concentrations were observed in rice samples collected adjacent to the plant, suggesting a potential impact of Hg emission from the coal fired power plant on the accumulation of Hg in rice in the area. Concentrations of MeHg in rice were positively correlated with soil MeHg, soil S, and gaseous elemental Hg (GEM) in ambient air. Soil MeHg was the most important factor controlling MeHg concentrations in rice. The methylation of Hg in soils may be controlled by factors such as the chemical speciation of inorganic Hg, soil S, and ambient GEM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Effects of Long-Term Winter Planted Green Manure on Distribution and Storage of Organic Carbon and Nitrogen in Water-Stable Aggregates of Reddish Paddy Soil Under a Double-Rice Cropping System

    Institute of Scientific and Technical Information of China (English)

    YANG Zeng-ping; ZHENG Sheng-xian; NIE Jun; LIAO Yu-lin; XIE Jian

    2014-01-01

    In agricultural systems, maintenance of soil organic matter has long been recognized as a strategy to reduce soil degradation. Manure amendments and green manures are management practices that can increase some nutrient contents and improve soil aggregation. We investigated the effects of 28 yr of winter planted green manure on soil aggregate-size distribution and aggregate-associated carbon (C) and nitrogen (N). The study was a randomized completed block design with three replicates. The treatments included rice-rice-fallow, rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass. The experiment was established in 1982 on a silty light clayey paddy soil derived from Quaternary red clay (classiifed as Fe-Accumuli-Stagnic Anthrosols) with continuous early and late rice. In 2009, soil samples were collected (0-15 cm depth) from the ifeld treatment plots and separated into water-stable aggregates of different sizes (i.e.,>5, 2-5, 1-2, 0.5-1, 0.25-0.5 and<0.25 mm) by wet sieving. The long-term winter planted green manure signiifcantly increased total C and N, and the formation of the 2-5-mm water-stable aggregate fraction. Compared with rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass, the rice-rice-fallow signiifcantly reduced 2-5-mm water-stable aggregates, with a signiifcant redistribution of aggregates into micro-aggregates. Long-term winter planted green manure obviously improved C/N ratio and macro-aggregate-associated C and N. The highest contribution to soil fertility was from macro-aggregates of 2-5 mm in most cases.

  6. Single- versus Multiple-Pest Infestation Affects Differently the Biochemistry of Tomato (Solanum lycopersicum 'Ailsa Craig').

    Science.gov (United States)

    Errard, Audrey; Ulrichs, Christian; Kühne, Stefan; Mewis, Inga; Drungowski, Mario; Schreiner, Monika; Baldermann, Susanne

    2015-11-25

    Tomato is susceptible to pest infestations by both spider mites and aphids. The effects of each individual pest on plants are known, whereas multiple-pest infestations have received little interest. We studied the effects of single- versus multiple-pest infestation by Tetranychus urticae and Myzus persicae on tomato biochemistry (Solanum lycopersicum) by combining a metabolomic approach and analyses of carotenoids using UHPLC-ToF-MS and volatiles using GC-MS. Plants responded differently to aphids and mites after 3 weeks of infestation, and a multiple infestation induced a specific metabolite composition in plants. In addition, we showed that volatiles emissions differed between the adaxial and abaxial leaf epidermes and identified compounds emitted particularly in response to a multiple infestation (cyclohexadecane, dodecane, aromadendrene, and β-elemene). Finally, the carotenoid concentrations in leaves and stems were more affected by multiple than single infestations. Our study highlights and discusses the interplay of biotic stressors within the terpenoid metabolism.

  7. Strong resistance against Rice grassy stunt virus is induced in transgenic rice plants expressing double-stranded RNA of the viral genes for nucleocapsid or movement proteins as targets for RNA interference.

    Science.gov (United States)

    Shimizu, Takumi; Ogamino, Takumi; Hiraguri, Akihiro; Nakazono-Nagaoka, Eiko; Uehara-Ichiki, Tamaki; Nakajima, Masami; Akutsu, Katsumi; Omura, Toshihiro; Sasaya, Takahide

    2013-05-01

    Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, causes significant economic losses in rice production in South, Southeast, and East Asian countries. Growing resistant varieties is the most efficient method to control RGSV; however, suitable resistance genes have not yet been found in natural rice resources. One of the most promising methods to confer resistance against RGSV is the use of RNA interference (RNAi). It is important to target viral genes that play important roles in viral infection and proliferation at an early stage of viral replication. Our recent findings obtained from an RNAi experiment with Rice stripe virus (RSV), a tenuivirus, revealed that the genes for nucleocapsid and movement proteins were appropriate targets for RNAi to confer resistance against RSV. In this study, we transformed rice plants by introducing an RNAi construct of the RGSV genes for the nucelocapsid protein pC5 or movement protein pC6. All progenies from self-fertilized transgenic plants had strong resistance against RGSV infection and did not allow the proliferation of RGSV. Thus, our strategy to target genes for nucleocapsid and movement proteins for conferring viral resistance might be applicable to the plant viruses in the genus Tenuivirus.

  8. Open-pit coal-mining effects on rice paddy soil composition and metal bioavailability to Oryza sativa L. plants in Cam Pha, northeastern Vietnam.

    Science.gov (United States)

    Martinez, Raul E; Marquez, J Eduardo; Hòa, Hoàng Thị Bích; Gieré, Reto

    2013-11-01

    This study quantified Cd, Pb, and Cu content, and the soil-plant transfer factors of these elements in rice paddies within Cam Pha, Quang Ninh province, northeastern Vietnam. The rice paddies are located at a distance of 2 km from the large Coc Sau open-pit coal mine. Electron microprobe analysis combined with backscattered electron imaging and energy-dispersive spectroscopy revealed a relatively high proportion of carbon particles rimmed by an iron sulfide mineral (probably pyrite) in the quartz-clay matrix of rice paddy soils at 20-30 cm depth. Bulk chemical analysis of these soils revealed the presence of Cd, Cu, and Pb at concentrations of 0.146±0.004, 23.3±0.1, and 23.5±0.1 mg/kg which exceeded calculated background concentrations of 0.006±0.004, 1.9±0.5, and 2.4±1.5 mg/kg respectively at one of the sites. Metals and metalloids in Cam Pha rice paddy soils, including As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn, were found in concentrations ranging from 0.2±0.1 to 140±3 mg/kg, which were in close agreement with toxic metal contents in mine tailings and Coc Sau coal samples, suggesting mining operations as a major cause of paddy soil contamination. Native and model Oryza sativa L. rice plants were grown in the laboratory in a growth medium to which up to 1.5 mg/kg of paddy soil from Cam Pha was added to investigate the effects on plant growth. A decrease in growth by up to 60% with respect to a control sample was found for model plants, whereas a decrease of only 10% was observed for native (Nep cai hoa vang variety) rice plants. This result suggests an adaptation of native Cam Pha rice plants to toxic metals in the agricultural lands. The Cd, Cu, and Pb contents of the native rice plants from Cam Pha paddies exceeded permitted levels in foods. Cadmium and Pb were highest in the rice plant roots with concentrations of 0.84±0.02 and 7.7±0.3 mg/kg, suggesting an intake of these metals into the rice plant as shown, for example, by Cd and Pb concentrations of 0

  9. Identification of Bt-transgenic Rice Plants for Resistance to Stripe Stem Borer (Chilo suppressalis) and Genetic Analysis of the Transgenes

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-xiang; YAO Fang-yin; LI Guang-xian; WEN Fu-jiang

    2002-01-01

    Resistance to herbicide Basta was used to identify Bt-transgenic rice plants and the progenies of crosses between the Bt-transgenic rice and the rice varieties cultivated in the Huang Huai area of China. The results demonstrated that the Basta-positive rice plants were highly resistant to stripe stem borer (Chilo suppressalis ) both in the laboratory and field tests. Both cryIA (b) and bar genes were expressed and co-inherited in both selfing and crossing progenies. Mendelian segregation of the marker gene bar was observed in F2 and BC1 progenies. The results implicates that it is possible to transfer cryIA (b) gene into other cultivated varieties through crosses and back crosses.

  10. Sclerotia of Rhizoctonia solani, Their Production on Infected Rice Plants and Their Population in Different Soil Types

    Directory of Open Access Journals (Sweden)

    I. Suwanto

    1997-12-01

    Full Text Available Production of sclerotia of Rhizoctonla solani on infected rice plants and their population in different soil types were evaluated during the year of 1992/1993 and 1993/1994. The production of sclerotia was estimated on 20 diseased rice plants and plant debris (rice straw placed on soil surface, in 10 cm depth, and in 20 cm depth. The population of sclerotia in the soil was estimated by separating the sclerotia from soil samples collected from different soil previously planted with different crops. Data indicated that during the rainy season of 1992/1993, the mean sclerotia produced were 14.85 and 10.95 per hill on the variety of IR64 and non-lR64, respectively. While during the dry season of 1993 the mean sclerotia produced on these varieties were 7.50 and 7 .25 per hill. On both varieties, the production of sclerotia was positively correlated with disease  severity of sheath blight, as indicated by the correlation coefficient of 0.90 and 0.70, for the variety of IR64 and non-IR64, reepectively. Their close relationship was estimated by the model of Y=-29.00+1.16x (R^2=0.82 and Y=-2.94+0.35x (R^2=0.45, for the variety of IR64 and non-IR.64, respectively. The production of sclerotia on the infected rice straw was significantly affected by the soil depth where the diseased straw were kept. On the straw of IR64, the sclerotia produced were 7.00, 5.25, and 1.25, when the straw were kept in the depth of 0, 10, and 20 cm, respectively. While on the straw of non-IR.64 variety, the sclerotia produced were 7.75, 5.25, and 0.50. when the straw were kept in the depth of 0, 10, and 20 cm, respectively. Highest number of sclerotia was observed in Ultisol soil previously planted with corn, while the smallest was in Ultisol previously planted with mungbean.

  11. Bioensaios para diagnóstico da resistência aos herbicidas imidazolinonas em arroz Bioassays for diagnosis of resistance to the herbicides imidazolinones in rice plants

    Directory of Open Access Journals (Sweden)

    A.C. Roso

    2010-06-01

    Full Text Available Cultivares de arroz resistentes aos herbicidas imidazolinonas têm proporcionado a utilização destes para o controle do arroz-vermelho, que é um dos principais problemas da cultura do arroz irrigado. No entanto, biótipos de arroz-vermelho resistentes aos herbicidas imidazolinonas têm ocorrido em várias lavouras dessa cultura. O objetivo deste trabalho foi desenvolver métodos expeditos para a identificação de plantas de arroz resistentes aos herbicidas imidazolinonas em diferentes fases do desenvolvimento da planta. Foram utilizados os cultivares de arroz IRGA 422 CL, SATOR CL e PUITÁ INTA CL como padrão resistente aos herbicidas imidazolinonas, e o cultivar IRGA 417, como padrão suscetível. Os bioensaios realizados em sementes, plântulas e afilhos discriminaram de forma efetiva e rápida plantas de arroz resistentes e suscetíveis. As concentrações discriminadoras aos herbicidas imazethapyr + imazapic para os bioensaios de sementes, plântulas e afilhos foram de 0,01, 4 e 3 mM, respectivamente. A utilização desses bioensaios permite a identificação de indivíduos resistentes mesmo durante o desenvolvimento da lavoura, proporcionando assim a adoção de medidas que possam manter a sustentabilidade do controle de arroz-vermelho por meio de cultivares resistentes aos herbicidas.Red rice is the most troublesome weed in rice paddy fields. Herbicide resistant rice cultivars allow red rice control through the herbicides imidazolinones. However, imidazolinone resistant red rice biotypes have occurred in several rice paddy fields. The aim of this study was to develop rapid methods to identify imidazolinone resistant rice plants at different stages of rice plant development. The rice cultivars IRGA 422 CL, SATOR CL and PUITÁ INTA CL were used as well-known resistant cultivars, and IRGA 417 as a well-known susceptible check. The seed, seedling, and tiller bioassays discriminated resistant and susceptible plants efficiently, being

  12. Effects of chlorantraniliprole and thiamethoxam rice seed treatments on egg numbers and first instar survival of Lissorhoptrus oryzophilus (Coleoptera: Curculionidae).

    Science.gov (United States)

    Lanka, S K; Ottea, J A; Beuzelin, J M; Stout, M J

    2013-02-01

    Effects of treatment of rice seeds with an anthranilic diamide, chlorantraniliprole, and a neonicotinoid, thiamethoxam, on egg laying and first instar survival in rice water weevil, Lissorhoptrus oryzophilus Kuschel, were examined under greenhouse conditions. Exposure of adult weevils to rice (6-7 leaf stage) grown from seeds treated with chlorantraniliprole and thiamethoxam resulted in reduction in numbers of eggs and first instars. The low egg numbers by adults exposed to chlorantraniliprole-treated plants was confirmed as a sublethal effect on adults: adult survival was not impacted after 4 d of feeding on foliage from chlorantraniliprole-treated plants but the number of eggs laid by these weevils was reduced when released on untreated plants. Furthermore, a comparison of first instar emergence from chlorantraniliprole-treated plants and from untreated plants infested with weevils previously exposed to this chemical suggested that chlorantraniliprole was also reducing egg or first instar survival. In contrast, adults that fed on foliage from thiamethoxam-treated plants showed increased mortality. Possible sublethal effects of thiamethoxam on the number of eggs laid by adults were investigated by infesting untreated plants with weevils that survived exposure to thiamethoxam via foliar feeding (7 microg active ingredient/seed). Prior exposure to thiamethoxam through adult feeding reduced egg numbers. However, potential larvicidal or ovicidal effects of thiamethoxam seed treatments could not be detected in this study because of low first instar emergence from both thiamethoxam-treated plants and from untreated plants infested with weevils previously exposed to this chemical. These experiments revealed that the two seed treatments accomplish weevil control in different ways.

  13. Response of leaf endophytic bacterial community to elevated CO2 at different growth stages of rice plant

    Directory of Open Access Journals (Sweden)

    Gaidi eRen

    2015-08-01

    Full Text Available Plant endophytic bacteria play an important role in plant growth and health. In the context of climate change, the response of plant endophytic bacterial communities to elevated CO2 at different rice growing stages is poorly understood. Using 454 pyrosequencing, we investigated the response of leaf endophytic bacterial communities to elevated CO2 (eCO2 at the tillering, filling and maturity stages of the rice plant under different nitrogen fertilization conditions (low nitrogen fertilization (LN and high nitrogen fertilization (HN. The results revealed that the leaf endophytic bacterial community was dominated by Gammaproteobacteria-affiliated families, such as Enterobacteriaceae and Xanthomonadaceae, which represent 28.7-86.8% and 2.14-42.6% of the total sequence reads, respectively, at all tested growth stages. The difference in the bacterial community structure between the different growth stages was greater than the difference resulting from the CO2 and nitrogen fertilization treatments. The eCO2 effect on the bacterial communities differed greatly under different nitrogen application conditions and at different growth stages. Specifically, eCO2 revealed a significant effect on the community structure under both LN and HN levels at the tillering stage; however, the significant effect of eCO2 was only observed under HN, rather than under the LN condition at the filling stage; no significant effect of eCO2 on the community structure at both the LN and HN fertilization levels was found at the maturity stage. These results provide useful insights into the response of leaf endophytic bacterial communities to elevated CO2 across rice growth stages.

  14. Generation of poly-β-hydroxybutyrate from acetate in higher plants: Detection of acetoacetyl CoA reductase- and PHB synthase- activities in rice.

    Science.gov (United States)

    Tsuda, Hirohisa; Shiraki, Mari; Inoue, Eri; Saito, Terumi

    2016-08-20

    It has been reported that Poly-β-hydroxybutyrate (PHB) is generated from acetate in the rice root. However, no information is available about the biosynthetic pathway of PHB from acetate in plant cells. In the bacterium Ralstonia eutropha H16 (R. eutropha), PHB is synthesized from acetyl CoA by the consecutive reaction of three enzymes: β-ketothiolase (EC: 2.3.1.9), acetoacetyl CoA reductase (EC: 1.1.1.36) and PHB synthase (EC: 2.3.1.-). Thus, in this study, we examined whether the above three enzymatic activities were also detected in rice seedlings. The results clearly showed that the activities of the above three enzymes were all detected in rice. In particular, the PHB synthase activity was detected specifically in the sonicated particulate fractions (2000g 10min precipitate (ppt) and the 8000g 30min ppt) of rice roots and leaves. In addition to these enzyme activities, several new experimental results were obtained on PHB synthesis in higher plants: (a) (14)C-PHB generated from 2-(14)C-acetate was mainly localized in the 2000g 10min ppt and the 8000g 30min ppt of rice root. (b) Addition of acetate (0.1-10mM) to culture medium of rice seedlings did not increase the content of PHB in the rice root or leaf. (c) In addition to C3 plants, PHB was generated from acetate in a C4 plant (corn) and in a CAM plant (Bryophyllum pinnatum). d) Washing with ethylenediaminetetraacetic acid (EDTA) strongly suggested that the PHB synthesized from acetate was of plant origin and was not bacterial contamination.

  15. Development of Selectable Marker-Free Transgenic Rice Plants with Enhanced Seed Tocopherol Content through FLP/FRT-Mediated Spontaneous Auto-Excision.

    Directory of Open Access Journals (Sweden)

    Hee-Jong Woo

    Full Text Available Development of marker-free transgenic plants is a technical alternative for avoiding concerns about the safety of selectable marker genes used in genetically modified (GM crops. Here, we describe the construction of a spontaneous self-excision binary vector using an oxidative stress-inducible modified FLP/FRT system and its successful application to produce marker-free transgenic rice plants with enhanced seed tocopherol content. To generate selectable marker-free transgenic rice plants, we constructed a binary vector using the hpt selectable marker gene and the rice codon-optimized FLP (mFLP gene under the control of an oxidative stress-inducible promoter between two FRT sites, along with multiple cloning sites for convenient cloning of genes of interest. Using this pCMF binary vector with the NtTC gene, marker-free T1 transgenic rice plants expressing NtTC were produced by Agrobacterium-mediated stable transformation using hygromycin as a selective agent, followed by segregation of selectable marker genes. Furthermore, α-, γ-, and total tocopherol levels were significantly increased in seeds of the marker-free transgenic TC line compared with those of wild-type plants. Thus, this spontaneous auto-excision system, incorporating an oxidative stress-inducible mFLP/FRT system to eliminate the selectable marker gene, can be easily adopted and used to efficiently generate marker-free transgenic rice plants. Moreover, nutritional enhancement of rice seeds through elevation of tocopherol content coupled with this marker-free strategy may improve human health and public acceptance of GM rice.

  16. Lowering intercellular melatonin levels by transgenic analysis of indoleamine 2,3-dioxygenase from rice in tomato plants.

    Science.gov (United States)

    Okazaki, Masateru; Higuchi, Kenji; Aouini, Asma; Ezura, Hiroshi

    2010-10-01

    Melatonin exists in numerous living organisms including vertebrates, insects, fungi, bacteria, and plants. Extensive studies have been conducted on the physiological roles of melatonin in various plant species. In plants, melatonin seems to act in antioxidant protection, as a growth promoter, and in photoperiodism. However, the mechanisms by which melatonin carries out these roles remain unclear. We manipulated the endogenous melatonin content in tomato plants by modifying the metabolic enzyme indoleamine 2,3-dioxygenase (IDO). The OsIDO gene was isolated from rice (Oryza sativa) and characterized using 3-D homology modeling and reverse genetic approaches. The amino acid sequence of OsIDO showed high homology to the Ustilago maydis IDO. The 3-D model structure of OsIDO is composed of a small and a large domain. Transgenic tomato plants constitutively expressing the OsIDO gene exhibited a decrease in their melatonin content. Moreover, the number of lateral leaflets decreased in transgenic plants. Protein extracts taken from these plants showed activity degradation, demonstrating the function of OsIDO. These results suggest the involvement of IDO in plant melatonin metabolism and a possible role in plant leaf development. © 2010 The Authors. Journal of Pineal Research © 2010 John Wiley & Sons A/S.

  17. Development and Transition of Rice Planting in China%我国水稻种植方式发展与转型(英文)

    Institute of Scientific and Technical Information of China (English)

    张玉屏; 朱德峰; 熊洪; 陈惠哲; 向镜; 林贤青

    2012-01-01

    [Objective] This paper aimed to clarify the rice planting methods and its supporting technology to be developed in rice producing areas in China. [Method] Evolvement of rice planting methods in rice producing areas in China and in representative rice-growth countries abroad, its characteristics, adaptability and key issues were analyzed. [Result] The analysis of development of rice planting method in China and abroad indicated that rice planting method was adapted to rice-based cropping system and ecological environment, and its transition accompanied with social and economic development. With agricultural labor transfer from agriculture to other industries since 1990’s, rice seedling throwing was gradually applied and in recent decades, while direct seeding and machine transplanting were practiced. Now, hand transplanting is still the main rice planting method, adopted in 50% of national rice planting area; seedling throwing, direct seeding and machine transplanting are conducted in 25% , 12% and 13% of the national rice planting area. [Conclusion] Machine transplanting should be a leading rice planting method. Though area covered with machine direct seeding is still small up to now, it can be practiced in some rice growing area due to labor saving and low cost. Leading planting methods and its supporting key technologies are proposed in various rice producing areas in the future.%[目的]分析我国水稻种植方式发展和转型特点,明确各稻区水稻种植方式的发展方向及需要研发的关键技术。[方法]分析国外代表性产稻国及我国主要稻区水稻种植方式的演变,水稻种植方式的特点,适应性及问题。[结果]国内外水稻种植方式的发展分析表明,水稻种植方式与水稻种植制度和生态环境相适应,随社会经济发展的发展而演变。我国90年代以来,随农村劳动力的转移,水稻抛秧面积逐渐发展,近十年来,水稻直播和机插秧面积发展较快。目前,手工

  18. Infestation Level Influences Oviposition Site Selection in the Tomato Leafminer Tuta absoluta (Lepidoptera: Gelechiidae

    Directory of Open Access Journals (Sweden)

    Thomas Bawin

    2014-11-01

    Full Text Available The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae, is a devastating pest that develops principally on solanaceous plants throughout South and Central America and Europe. In this study, we tested the influence of three levels of T. absoluta infestations on the attraction and oviposition preference of adult T. absoluta. Three infestation levels (i.e., non-infested plants, plants infested with 10 T. absoluta larvae, and plants infested with 20 T. absoluta larvae were presented by pairs in a flying tunnel to groups of T. absoluta adults. We found no differences in terms of adult attraction for either level of infestations. However, female oviposition choice is influenced by larvae density on tomato plants. We discuss the underlying mechanisms and propose recommendations for further research.

  19. The occurrence of arthropods in processed rice products in Malaysia

    Institute of Scientific and Technical Information of China (English)

    Mariana A; Heah SK; Wong AL; Ho TM

    2010-01-01

    Objective:To determine distribution of arthropods in processed rice products such as rice flour and rice cereal-based infant food. Methods: Random samples of rice flour and rice cereal-based infant food purchased from commercial outlets were examined for the presence of arthropods using a modified Berlese Tullgren Funnel Method. Mites were mounted prior to identification and weevils were directly identified. Results: For non-expired products, infestation was found in 6.7%of rice flour and none was found in rice cereal-based infant food samples. The arthropods found in the flour samples were Cheyletus spp., Suidasia pontifica (S. pontifica), Tarsonemus spp., Tyrophagus putrescentiae (T. putrescentiae), Sitophilus granarius (S. granarius) and Sitophilus oryzae (S. oryzae). Others which cannot be identified were Oribatid and Prostigmatid mites. The most common mites in rice flour were Tarsonemus spp. (69.1%), followed by S. pontifica (18.2%). For expired products, only one sample of rice cereal-based infant food was infested and the infestation was by mites of the family Tydeidae. Conclusions:This study demonstrates the presence of 4 allergenic species of S. pontifica, T. putrescentiae, S. granarius and S. oryzae in rice flour. These arthropods can contribute to the incidence of anaphylaxis upon consumption by atopic individuals. There was no infestation of arthropods in rice cereal-based infant food surveyed except for an expired product in a moderate rusty tin container.

  20. Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance.

    Science.gov (United States)

    Kumar, S; Arul, L; Talwar, D

    2010-01-01

    We report on generation of marker-free (‘clean DNA’) transgenic rice (Oryza sativa), carrying minimal gene-expression-cassettes of the genes of interest, and evaluation of its resistance to yellow stem borer Scirpophaga incertulas (Lepidoptera: Pyralidae). The transgenic indica rice harbours a translational fusion of 2 different Bacillus thuringiensis (Bt) genes, namely cry1B-1Aa, driven by the green-tissue-specific phosphoenol pyruvate carboxylase (PEPC) promoter. Mature seed-derived calli of an elite indica rice cultivar Pusa Basmati-1 were co-bombarded with gene-expression-cassettes (clean DNA fragments) of the Bt gene and the marker hpt gene, to generate marker-free transgenic rice plants. The clean DNA fragments for bombardment were obtained by restriction digestion and gel extraction. Through biolistic transformation, 67 independent transformants were generated. Transformation frequency reached 3.3%, and 81% of the transgenic plants were co-transformants. Stable integration of the Bt gene was confirmed, and the insert copy number was determined by Southern analysis. Western analysis and ELISA revealed a high level of Bt protein expression in transgenic plants. Progeny analysis confirmed stable inheritance of the Bt gene according to the Mendelian (3:1) ratio. Insect bioassays revealed complete protection of transgenic plants from yellow stem borer infestation. PCR analysis of T2 progeny plants resulted in the recovery of up to 4% marker-free transgenic rice plants.

  1. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances.

    Science.gov (United States)

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot(-1)). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot(-1)) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot(-1)) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.

  2. Improving Lowland Rice (O. sativa L. cv. MR219 Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    Directory of Open Access Journals (Sweden)

    Perumal Palanivell

    2015-01-01

    Full Text Available High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1. Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1 significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot−1 and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.

  3. Infestation caused by acanthocephala

    Directory of Open Access Journals (Sweden)

    Daniele Crotti

    2009-03-01

    Full Text Available An on-line case of infestation caused by M. moniliformis is descripted. This rodents’ worm, belonging to acanthocephala, can be rarely responsible of human intestinal pathology. The case is the pretext for a brief revision on this parasitosis. So, biological, epidemiological, clinical and diagnostical findings are reported.

  4. GUS组织化学染色法--一种快速筛选抗二化螟转Bt cry1Ab基因水稻的方法%GUS histochemical assay: A rapid way to screen striped stem boren (chilo suppressalis) resistant transgenic rice with a cry1ab gene from Bt (Bacillus thuringiensis)

    Institute of Scientific and Technical Information of China (English)

    吴刚; 崔海瑞; 舒庆尧; 叶恭银; 夏英武

    2000-01-01

    @@ The time-consuming in vitro bioassay is the frequently used method to screen insect resistant transgenic rice and often remains a tedious task for us. Here we reported the resistance of Bt transgenic rice to striped stem borer by means of field natural infestation and in vitro bioassay. We found that there was a significant correlation between the number of GUS positive plants and the number of insect resistant plants, thus GUS histochemical assay could be used as a rapid and convenient method to screen insect resistant plants.

  5. 广东省水稻种植机械化的SWOT分析%SWOT analysis of rice planting mechanization in Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    郑俊敏; 张璐

    2014-01-01

    文章以水稻种植机械化为着眼点,通过应用SWOT分析研究的理论和方法,结合广东省水稻生产的特点,对水稻种植机械化发展过程中存在的优势、劣势、机会与威胁进行综合分析;建立了广东省水稻种植机械化的SWOT矩阵,分析广东省水稻种植机械化的现实情况,构建四种战略组合,以期为广东省水稻种植机械化发展提出政策与建议,为管理决策提供参考。%This paper takes the rice planting mechanization as the starting point and conducts comprehensive analysis on advantage, disadvantage, opportunity and threat in the process of rice planting mechanization, through application of theory and method of SWOT analysis.The SWOT matrix of rice planting mechanization is established in Guangdong Province, with analysis on the reality of rice planting mechanization in Guangdong province. Four kinds of strategy is con-structed for the rice planting mechanization and development in Guangdong Province.

  6. The method for detecting biological parameter of rice growth and early planting of paddy crop by using multi temporal remote sensing data

    Science.gov (United States)

    Domiri, D. D.

    2017-01-01

    Rice crop is the most important food crop for the Asian population, especially in Indonesia. During the growth of rice plants have four main phases, namely the early planting or inundation phase, the vegetative phase, the generative phase, and bare land phase. Monitoring the condition of the rice plant needs to be conducted in order to know whether the rice plants have problems or not in its growth. Application of remote sensing technology, which uses satellite data such as Landsat 8 and others which has a spatial and temporal resolution is high enough for monitoring the condition of crops such as paddy crop in a large area. In this study has been made an algorithm for monitoring rapidly of rice growth condition using Maximum of Vegetation Index (EVI Max). The results showed that the time of early planting can be estimated if known when EVI Max occurred. The value of EVI Max and when it occured can be known by trough spatial analysis of multitemporal EVI Landsat 8 or other medium spatial resolution satellites.

  7. TPS46, a Rice Terpene Synthase Conferring Natural Resistance to Bird Cherry-Oat Aphid, Rhopalosiphum padi (Linnaeus)

    Science.gov (United States)

    Sun, Yang; Huang, Xinzheng; Ning, Yuese; Jing, Weixia; Bruce, Toby J. A.; Qi, Fangjun; Xu, Qixia; Wu, Kongming; Zhang, Yongjun; Guo, Yuyuan

    2017-01-01

    Plant terpene synthases (TPSs) are key enzymes responsible for terpene biosynthesis, and can play important roles in defense against herbivore attack. In rice, the protein sequence of TPS46 was most closely related to maize TPS10. However, unlike maize tps10, tps46 was also constitutively expressed in rice even in the absence of herbivore attack. Potential roles or constitutive emissions of specific volatiles may due to the constitutive expressions of tps46 in rice. Therefore, in the present study, RNA interference (Ri) and overexpression (Oe) rice lines were generated to investigate the potential function of TPS46 in Oryza sativa sp. japonica. Interestingly, the rice plants become more susceptible to Rhopalosiphum padi when expression of tps46 was silenced compared with Wt in greenhouse conditions. Artificial infestation bioassays further confirmed that Ri rice lines were susceptible to R. padi, whereas Oe rice lines were repellent to R. padi. Based on GC-MS and ToF-MS analysis, a total of eight volatile products catalyzed by TPS46 in rice were identified. Among them, only limonene and Eβf could be detected in all the Ri, Oe, and Wt lines, whereas other six volatiles were only found in the blend of volatiles from Oe lines. Moreover, the amount of constitutive limonene and Eβf in the Ri lines was significantly lower than in Wt lines, while the amounts of these two volatiles in the Oe line were obviously higher than in control rice. Our data suggested that the constitutive emissions of Eβf and limonene regulated by the constitutive expression of tps46 may play a crucial role in rice defense against R. padi. Consequently, tps46 could be a potential target gene to be employed for improving the resistance of plants to aphids. PMID:28217135

  8. Phenotypic Expression of Whitebacked Planthopper Resistance in the Newly Established japonica / indica Doubled Haploid Rice Population

    Institute of Scientific and Technical Information of China (English)

    Kazushige SOGAWA; SUN Zong-xiu; QIAN Qian; ZENG Da-li

    2004-01-01

    A new doubled haploid (DH) rice population was established from a cross between WBPH-resistant japonica Chunjiang 06 (C J-06) and susceptible indica TN1. Sucking inhibitory and ovicidal resistance of the DH rice lines were evaluated on the basis of non-preference response of WBPH immigrants and honeydew excretion by WBPH females, and appearance of watery lesions in the necrotic discoloration of leaf sheaths ovipositied by WBPH,respectively. Both the major gene resistance to WBPH, sucking inhibitory and ovicidal resistance, showed 1 (resistant): 1 (susceptible) segregation ratio in the DH population. Relative density of WBPH populations and damage scores in the DH population indicated combined functions of both the major resistance genes as well as QTLs affecting the host plant response to WBPH infestations. Thus, the newly developed CJ-06/TN1 DH population could be a useful material to analyze major genes and QTLs for WBPH resistance in japonica rice.

  9. Backbone cyclised peptides from plants show molluscicidal activity against the rice pest Pomacea canaliculata (golden apple snail).

    Science.gov (United States)

    Plan, Manuel Rey R; Saska, Ivana; Cagauan, Arsenia G; Craik, David J

    2008-07-09

    Golden apple snails ( Pomacea canaliculata) are serious pests of rice in South East Asia. Cyclotides are backbone cyclized peptides produced by plants from Rubiaceae and Violaceae. In this study, we investigated the molluscicidal activity of cyclotides against golden apple snails. Crude cyclotide extracts from both Oldenlandia affinis and Viola odorata plants showed molluscicidal activity comparable to the synthetic molluscicide metaldehyde. Individual cyclotides from each extract demonstrated a range of molluscicidal activities. The cyclotides cycloviolacin O1, kalata B1, and kalata B2 were more toxic to golden apple snails than metaldehyde, while kalata B7 and kalata B8 did not cause significant mortality. The toxicity of the cyclotide kalata B2 on a nontarget species, the Nile tilapia ( Oreochromis niloticus), was three times lower than the common piscicide rotenone. Our findings suggest that the existing diversity of cyclotides in plants could be used to develop natural molluscicides.

  10. Dual RNA-seq reveals Meloidogyne graminicola transcriptome and candidate effectors during the interaction with rice plants.

    Science.gov (United States)

    Petitot, Anne-Sophie; Dereeper, Alexis; Agbessi, Mawusse; Da Silva, Corinne; Guy, Julie; Ardisson, Morgane; Fernandez, Diana

    2016-08-01

    Root-knot nematodes secrete proteinaceous effectors into plant tissues to facilitate infection by suppressing host defences and reprogramming the host metabolism to their benefit. Meloidogyne graminicola is a major pest of rice (Oryza sativa) in Asia and Latin America, causing important crop losses. The goal of this study was to identify M. graminicola pathogenicity genes expressed during the plant-nematode interaction. Using the dual RNA-sequencing (RNA-seq) strategy, we generated transcriptomic data of M. graminicola samples covering the pre-parasitic J2 stage and five parasitic stages in rice plants, from the parasitic J2 to the adult female. In the absence of a reference genome, a de novo M. graminicola transcriptome of 66 396 contigs was obtained from those reads that were not mapped on the rice genome. Gene expression profiling across the M. graminicola life cycle revealed key genes involved in nematode development and provided insights into the genes putatively associated with parasitism. The development of a 'secreted protein prediction' pipeline revealed a typical set of proteins secreted by nematodes, as well as a large number of cysteine-rich proteins and putative nuclear proteins. Combined with expression data, this pipeline enabled the identification of 15 putative effector genes, including two homologues of well-characterized effectors from cyst nematodes (CLE-like and VAP1) and a metallothionein. The localization of gene expression was assessed by in situ hybridization for a subset of candidates. All of these data represent important molecular resources for the elucidation of M. graminicola biology and for the selection of potential targets for the development of novel control strategies for this nematode species.

  11. Rice Germplasm Resources in China

    Institute of Scientific and Technical Information of China (English)

    YINGCunshan

    1994-01-01

    China is one of the origin countries in Asia of cultiv ated rice (O. sativaL.), and rice is one of the aged-long food crops in the country. The results of the 14C evaluation on the carbonified rice grains unearthed from Hemudu in Yuyao County and Luojiajiao in Tongxiang County of Zhejiang Province indicated that rice in these area has been planted more than 7,000 yrs and indica (hsien) and japonica (keng) rices coexisted with each other.

  12. A conserved function for Arabidopsis SUPERMAN in regulating floral-whorl cell proliferation in rice, a monocotyledonous plant.

    Science.gov (United States)

    Nandi, A K; Kushalappa, K; Prasad, K; Vijayraghavan, U

    2000-02-24

    Studies of floral organ development in two dicotyledonous plants, Arabidopsis thaliana and Antirrhinum majus, have shown that three sets of genes (A, B and C) can pattern sepals, petals, stamens and carpels [1] [2]. Mechanisms that define boundaries between these floral whorls are unclear, however. The Arabidopsis gene SUPERMAN (SUP), which encodes a putative transcription factor, maintains the boundary between stamens and carpels [3] [4] [5], possibly by regulating cell proliferation. By overexpressing SUP cDNA in rice, we examined whether its effects on whorl boundaries are conserved in a divergent monocotyledonous species. High-level ectopic SUP expression in transgenic rice resulted in juvenile death or dwarf plants with decreased axillary growth. Plants with lower levels of SUP RNA were vegetatively normal, but the flowers showed ubiquitous ventral carpel expansion. This was often coupled with reduced stamen number, or occurrence of third-whorl stamen-carpel mosaic organs. Additionally, proliferation of second-whorl ventral cells produced adventitious lodicules, and flowers lost the asymmetry that is normally inherent to this whorl. We predict that SUP is a conserved regulator of floral whorl boundaries and that it affects cell proliferation.

  13. Characterization of IRE1 ribonuclease-mediated mRNA decay in plants using transient expression analyses in rice protoplasts.

    Science.gov (United States)

    Hayashi, Shimpei; Wakasa, Yuhya; Ozawa, Kenjirou; Takaiwa, Fumio

    2016-06-01

    In some eukaryotes, endoplasmic reticulum (ER) stress induces regulated inositol-requiring enzyme 1 (IRE1)-dependent decay (RIDD) of mRNAs. Recently, the expression levels of the mRNAs encoding some secretory proteins were reported to be downregulated by RIDD in the vegetative tissues of plants. However, the characteristics of plant RIDD have been insufficiently investigated due to difficulty of in planta analyses. Here, the RIDD susceptibilities of various mRNAs that are difficult to analyze in planta were examined using transient expression analyses of rice protoplasts. In this system, the mRNAs encoding three rice seed storage proteins (SSPs) - namely α-globulin, 16-kDa prolamin and 10-kDa prolamin - were downregulated in response to ER stress. The rapid ER stress-induced degradation of these mRNAs was repressed in cells in which the ribonuclease activity of IRE1 was specifically abolished by genome editing, suggesting that the mRNAs encoding certain SSPs are strong targets of RIDD. Furthermore, we investigated whether these RIDD targets are substrates of the IRE1 ribonuclease using a recombinant IRE1 protein, and identified candidate IRE1-mediated cleavage sites. Overall, the results demonstrate the existence of a post-transcriptional mechanism of regulation of SSPs, and illustrate the basic and multifaceted characteristics of RIDD in higher plants.

  14. Migration of Azospirillum brasilense Yu62 from Root to Stem and Leaves Inside Rice and Tobacco Plants

    Institute of Scientific and Technical Information of China (English)

    CHIFeng; SHENShi-Hua; CHENSan-Feng; JINGYu-Xiang

    2004-01-01

    Azospirillum brasilense Tarrand, Krieg et Doebereiner is one of the important plant growthpromotion endophytes. A. brasilense Yu62 tagged with gfp gene was inoculated into roots of rice and tobacco seedlings, which were then, cultured in gnotobiotic condition. At a certain days after inoculation the different portions of the seedling were observed under laser confocal microscope, resulting in that A.brasilense Yu62 bacteria were colonized in epidermal and cortical cells, intercellular spaces and vascular system of stem and leaf tissue interiors besides in roots. Higher populations of the bacteria isolated from roots, stems and leaves indicated that A. brasilense Yu62 bacteria could ascend themselves from roots to stems and leaves of rice and tobacco. This observation lays down the foundation for ecology and cell morphology of bacterial migration inside plants, interaction between A. brasilense Yu62 bacteria and host cells as well as the plant-growth promotion, provides scientific basis for further application, and is of importance in science and practice.

  15. Indoleacetic acid production and plant growth promoting potential of bacterial endophytes isolated from rice (Oryza sativa L.) seeds.

    Science.gov (United States)

    Shahzad, Raheem; Waqas, Muhammad; Khan, Abdul Latif; Al-Hosni, Khadija; Kang, Sang-Mo; Seo, Chang-Woo; Lee, In-Jung

    2017-06-01

    Bacterial endophytes from the phyllosphere and rhizosphere have been used to produce bioactive metabolites and to promote plant growth. However, little is known about the endophytes residing in seeds. This study aimed to isolate and identify seed-borne bacterial endophytes from rice and elucidate their potential for phytohormone production and growth enhancement. The isolated endophytes included Micrococcus yunnanensis RWL-2, Micrococcus luteus RWL-3, Enterobacter soli RWL-4, Leclercia adecarboxylata RWL-5, Pantoea dispersa RWL-6, and Staphylococcus epidermidis RWL-7, which were identified using 16S rRNA sequencing and phylogenetic analysis. These strains were analyzed for indoleacetic acid (IAA) production by using GC-MS and IAA was found in the range of 11.50 ± 0.77 μg ml(-1) to 38.80 ± 1.35 μg ml(-1). We also assessed the strains for plant growth promoting potential because these isolates were able to produce IAA in pure culture. Most of the growth attributes of rice plants (shoot and root length, fresh and dry biomass, and chlorophyll content) were significantly increased by bacterial endophytes compared to the controls. These results show that IAA producing bacterial endophytes can improve hostplant growth traits and can be used as bio-fertilizers.

  16. Plant Temperature for Sterile Alteration of a Temperature-Sensitive Genic Male Sterile Rice, Peiai64S

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The forecast of sterile alteration for the temperature-sensitive genic male sterile (TGMS) line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter,the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively,whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter.Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.

  17. Identification of rice cultivars resistant to Lissorhoptrus oryzophilus (Coleoptera: Curculionidae), and their use in an integrated management program.

    Science.gov (United States)

    Stout, M J; Rice, W C; Linscombe, S D; Bollich, P K

    2001-08-01

    The rice water weevil, Lissorhoptrus oryzophilus Kuschel, is the most destructive insect pest of rice in the United States and is a particularly severe pest in Louisiana. The current management program for this insect in Louisiana relies heavily on insecticides, most notably the seed treatment fipronil (Icon). Diversification of the management program by incorporation of alternative strategies is needed to improve the effectiveness and long-term stability of the program. In the three experiments reported here, three components of a diversified management program for the rice water weevil in Louisiana--host plant resistance, treatment of seeds with Icon, aid the cultural practice of delayed flooding--were investigated. Comparison of the densities of weevil larvae on the roots of several commercial cultivars indicated that the long-grain cultivar 'Jefferson' was more resistant to infestation by the rice water weevil than the other cultivars. The medium-grain cultivars 'Bengal', 'Earl' and 'Mars' and the long-grain variety 'Cocodrie' were the most susceptible to infestation. Comparison of yield data from untreated plots and plots treated with Icon indicated that the long-grain cultivars Cocodrie, Lemont, and Jefferson were more tolerant of weevil injury than the other cultivars. A 2-wk delay in flooding was associated with yield benefits in plots not treated with Icon. Treatment of seeds with Icon controlled weevils in all three screening experiments. The implications of these results for the development of an integrated management program for the rice water weevil are discussed.

  18. Genetic variation and host-parasite specificity of Striga resistance and tolerance in rice: the need for predictive breeding.

    Science.gov (United States)

    Rodenburg, Jonne; Cissoko, Mamadou; Kayongo, Nicholas; Dieng, Ibnou; Bisikwa, Jenipher; Irakiza, Runyambo; Masoka, Isaac; Midega, Charles A O; Scholes, Julie D

    2017-02-13

    The parasitic weeds Striga asiatica and Striga hermonthica cause devastating yield losses to upland rice in Africa. Little is known about genetic variation in host resistance and tolerance across rice genotypes, in relation to virulence differences across Striga species and ecotypes. Diverse rice genotypes were phenotyped for the above traits in S. asiatica- (Tanzania) and S. hermonthica-infested fields (Kenya and Uganda) and under controlled conditions. New rice genotypes with either ecotype-specific or broad-spectrum resistance were identified. Resistance identified in the field was confirmed under controlled conditions, providing evidence that resistance was largely genetically determined. Striga-resistant genotypes contributed to yield security under Striga-infested conditions, although grain yield was also determined by the genotype-specific yield potential and tolerance. Tolerance, the physiological mechanism mitigating Striga effects on host growth and physiology, was unrelated to resistance, implying that any combination of high, medium or low levels of these traits can be found across rice genotypes. Striga virulence varies across species and ecotypes. The extent of Striga-induced host damage results from the interaction between parasite virulence and genetically determined levels of host-plant resistance and tolerance. These novel findings support the need for predictive breeding strategies based on knowledge of host resistance and parasite virulence.

  19. Whole-plant growth and N utilization in transgenic rice plants with increased or decreased Rubisco content under different CO2 partial pressures.

    Science.gov (United States)

    Sudo, Emi; Suzuki, Yuji; Makino, Amane

    2014-11-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) strongly limits photosynthesis at lower CO2 concentration [CO2] whereas [corrected] Rubisco limitation is cancelled by elevated [CO2]. Therefore, increase or reduction in Rubisco content by transformation with a sense or an antisense RBCS construct are expected to alter the biomass production under different CO2 levels. RBCS-sense (125% Rubisco of wild-type) and -antisense (35% Rubisco of wild-type) rice (Oryza sativa L.) plants were grown for 63 days at three different CO2 levels: low [CO2] (28 Pa), normal [CO2] (40 Pa) and elevated [CO2] (120 Pa). The biomass of RBCS-sense plants was 32% and 15% greater at low [CO2] and normal [CO2] than that of the wild-type plants, respectively, but did not differ at elevated [CO2]. Conversely, the biomass of RBCS-antisense plants was the smallest at low [CO2]. Thus, overproduction of Rubisco was effective for biomass production at low [CO2]. Greater biomass production at low [CO2] in RBCS-sense plants was caused by an increase in the net assimilation rate, and associated with an increase in the amount of N uptake. Furthermore, Rubisco overproduction in RBCS-sense plants was also promoted at low [CO2]. Although it seems that low [CO2]-growth additionally stimulates the effect of RBCS overexpression, such a phenomenon observed at low [CO2] was mediated through an increase in total leaf N content. Thus, the dependence of the growth improvement in RBCS-sense rice on growth [CO2] was closely related to the degree of Rubisco overproduction which was accompanied not only by leaf N content but also by whole plant N content.

  20. Endophytic colonization of rice (Oryza sativa L. by the diazotrophic bacterium Burkholderia kururiensis and its ability to enhance plant growth

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    Katherine A. Mattos

    2008-09-01

    Full Text Available Burkholderia kururiensis is a diazotrophic bacterium originally isolated from a polluted aquifer environment and presents a high level of similarity with the rice endophyte "B. brasilensis" species. This work assessed the ability of B. kururiensis to endophytically colonize rice plantlets by monitoring different tissues of root-inoculated plants for the presence of bacterial growth in different media, electron microscopy and by 16S rDNA analysis. Observations of roots, stems and leaves of inoculated rice plantlets by electron microscopy revealed B. kururiensis colonization predominantly on root hair zones, demonstrating endophytic colonization primarily through the endodermis, followed by spreading into xylem vessels, a possible pathway leading to aerial parts. Although indifferent for the bacterial growth itself, addition of a nitrogen source was a limiting factor for endophytic colonization. As endophytic colonization was directly associated to an enhanced plant development, production of phytohormone auxin/indole-3-acetic acid by B. kururiensis was assayed with transgenic rice plantlets containing an auxin-responsive reporter (DR5-GUS. Our findings suggest the ability of auxin production by plant-associated B. kururiensis which may have a stimulatory effect on plant development, as evidenced by activation of DR5-GUS. We hereby demonstrate, for the first time, the ability of B. kururiensis to endophytically colonize rice, promoting both plant growth and rice grain yield.Burkholderia kururiensis é uma bactéria diazotrófica, originalmente isolada de um ambiente aquático poluído e apresenta alto nível de similaridade com a espécie endofítica "B. brasilensis" encontrada na planta de arroz. Este artigo demonstrou a habilidade de B. kururiensis colonizar endofiticamente plântulas de arroz, após esta bactéria ter sido inoculada na raiz das plantas. Esta capacidade foi confirmada pelo crescimento bacteriano em diferentes tecidos da planta

  1. ZINC-INDUCED FACILITATOR-LIKE family in plants: lineage-specific expansion in monocotyledons and conserved genomic and expression features among rice (Oryza sativa paralogs

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    Lopes Karina L

    2011-01-01

    Full Text Available Abstract Background Duplications are very common in the evolution of plant genomes, explaining the high number of members in plant gene families. New genes born after duplication can undergo pseudogenization, neofunctionalization or subfunctionalization. Rice is a model for functional genomics research, an important crop for human nutrition and a target for biofortification. Increased zinc and iron content in the rice grain could be achieved by manipulation of metal transporters. Here, we describe the ZINC-INDUCED FACILITATOR-LIKE (ZIFL gene family in plants, and characterize the genomic structure and expression of rice paralogs, which are highly affected by segmental duplication. Results Sequences of sixty-eight ZIFL genes, from nine plant species, were comparatively analyzed. Although related to MSF_1 proteins, ZIFL protein sequences consistently grouped separately. Specific ZIFL sequence signatures were identified. Monocots harbor a larger number of ZIFL genes in their genomes than dicots, probably a result of a lineage-specific expansion. The rice ZIFL paralogs were named OsZIFL1 to OsZIFL13 and characterized. The genomic organization of the rice ZIFL genes seems to be highly influenced by segmental and tandem duplications and concerted evolution, as rice genome contains five highly similar ZIFL gene pairs. Most rice ZIFL promoters are enriched for the core sequence of the Fe-deficiency-related box IDE1. Gene expression analyses of different plant organs, growth stages and treatments, both from our qPCR data and from microarray databases, revealed that the duplicated ZIFL gene pairs are mostly co-expressed. Transcripts of OsZIFL4, OsZIFL5, OsZIFL7, and OsZIFL12 accumulate in response to Zn-excess and Fe-deficiency in roots, two stresses with partially overlapping responses. Conclusions We suggest that ZIFL genes have different evolutionary histories in monocot and dicot lineages. In rice, concerted evolution affected ZIFL duplicated genes

  2. Bioaccumulation and translocation of polyhalogenated compounds in rice (Oryza sativa L.) planted in paddy soil collected from an electronic waste recycling site, South China.

    Science.gov (United States)

    Zhang, Yun; Luo, Xiao-Jun; Mo, Ling; Wu, Jiang-Ping; Mai, Bi-Xian; Peng, Yong-Hong

    2015-10-01

    The bioaccumulation and translocation of polyhalogenated compounds (PHCs) in rice planted in the paddy soils of an electronic waste (e-waste) recycling site were investigated, along with the effect of contaminated soils on rice growth. The PHCs included polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and dechlorane plus (DPs). The morphological development and all measured physiological parameters of rice plants except for peroxidase were significantly inhibited by e-waste contaminated soils. Specifically, soil-root bioaccumulation factors (RCFs) increased with increasing logarithm of octanol-water partition coefficient (logKow) for PCBs, but decreased for PBDEs. During translocation from root to stem, translocation factors (TFs) and logKow were positively correlated. However, the accumulation mechanism in the leaf was concentration-dependent. In the high concentration exposure group, translocation play more important role in determination PHCs burden in leaf than atmospheric uptake, with logTF (from stem to leaf) being positively correlated with logKow. In contrast, in the low exposure and control groups, logTF (from stem to leaf) was negatively correlated with logKow. In addition, Syn-DP was selectively accumulated in plant tissues. In conclusion, this study demonstrates that e-waste contaminated soils affect rice growth, revealed the rule of the bioaccumulation and translocation of PHCs in rice plants.

  3. Plant Type and Its Effects on Canopy Structure at Heading Stage in Various Ecological Areas for a Two-line Hybrid Rice Combination, Liangyoupeijiu

    Institute of Scientific and Technical Information of China (English)

    LU Chuan-gen; HU Ning; YAO Ke-min; XIA Shi-jian; QI Qing-ming

    2010-01-01

    A two-line hybrid rice combination, Liangyoupeijiu, was used to estimate several factors of plant type, and environmental models for these factors at the heading stage were established using the data of eight ecological experimental sites in 2006 and 2007. According to climatic data from 1951 to 2005, the differences in those factors and their effects on plant canopy were analyzed for four rice cropping areas in China, including South China, the middle-lower reaches of the Yangtze River, Sichuan Basin, and river valley in Yunnan, China. The thickness of leaf layer (the distance from pulvinus of the third leaf from the top to the tip of flag leaf) and distribution of leaf area could be used as candidate indices for the plant type of a rice canopy.

  4. Retention of OsNMD3 in the cytoplasm disturbs protein synthesis efficiency and affects plant development in rice.

    Science.gov (United States)

    Shi, Yanyun; Liu, Xiangling; Li, Rui; Gao, Yaping; Xu, Zuopeng; Zhang, Baocai; Zhou, Yihua

    2014-07-01

    The ribosome is the basic machinery for translation, and biogenesis of ribosomes involves many coordinated events. However, knowledge about ribosomal dynamics in higher plants is very limited. This study chose a highly conserved trans-factor, the 60S ribosomal subunit nuclear export adaptor NMD3, to characterize the mechanism of ribosome biogenesis in the monocot plant Oryza sativa (rice). O. sativa NMD3 (OsNMD3) shares all the common motifs and shuttles between the nucleus and cytoplasm via CRM1/XPO1. A dominant negative form of OsNMD3 with a truncated nuclear localization sequence (OsNMD3(ΔNLS)) was retained in the cytoplasm, consequently interfering with the release of OsNMD3 from pre-60S particles and disturbing the assembly of ribosome subunits. Analyses of the transactivation activity and cellulose biosynthesis level revealed low protein synthesis efficiency in the transgenic plants compared with the wild-type plants. Pharmaceutical treatments demonstrated structural alterations in ribosomes in the transgenic plants. Moreover, global expression profiles of the wild-type and transgenic plants were investigated using the Illumina RNA sequencing approach. These expression profiles suggested that overexpression of OsNMD3(ΔNLS) affected ribosome biogenesis and certain basic pathways, leading to pleiotropic abnormalities in plant growth. Taken together, these results strongly suggest that OsNMD3 is important for ribosome assembly and the maintenance of normal protein synthesis efficiency.

  5. Overexpression of OsDPR, a novel rice gene highly expressed under iron deficiency, suppresses plant growth.

    Science.gov (United States)

    Naren; Zhang, Peng; Ma, Dengke; Wang, Yi; Li, Shuang; Yin, Liping

    2012-12-01

    Preliminary microarray analysis of cDNA from rice roots revealed an up-regulated transcript that was highly expressed in a five-day iron deficiency treatment. The entire sequence of this gene was determined by bioinformatics analysis. There were no proteins with significant levels of similarity detected in public databases. This novel gene with unknown biological function was designated as OsDPR (dwarf phenotype-related gene). We constructed a stable plant expression vector pCAMBIA1302-OsDPR::GFP and produced transgenic tobacco plants. The phenotypes suggested that OsDPR restrained the growth of transformed plants. To understand the mechanisms of this suppression effect, cell size and number were compared between transformants and wild-type plants. The cell proliferation rate was lower in OsDPR transgenic BY-2 cells than in wild-type cells, but OsDPR expression did not affect cell size. Moreover, the cell division-related gene CyclinD2.1, which is involved in plant growth, was down-regulated in transgenic tobacco plants. These findings suggested that the novel iron-regulated gene OsDPR is responsible for the nanism phenotype of transgenic seedlings because of the inhibition of plant cell proliferation.

  6. 水稻镉代谢与控制研究进展%Advances in Research of Cadmium Metabolism and Control in Rice Plants

    Institute of Scientific and Technical Information of China (English)

    朱智伟; 陈铭学; 牟仁祥; 曹赵云; 张卫星; 林晓燕

    2014-01-01

    水稻具有吸附镉的特性,使得镉成为稻米产品的主要污染物,影响粮食供给安全和食品安全。本文从水稻吸收积累镉的3个环节,即根系对镉的活化和吸收、木质部的装载和运输、经节间韧皮部富集到水稻籽粒中,综合评述了镉在水稻生长过程中的代谢规律,运转蛋白和关键基因的控制机制,环境和投入品对水稻吸收镉的影响,以及水稻镉控制的研究进展。并结合中国实际情况,从农业可持续生产、控制稻米安全角度,辨证地探讨水稻镉控制的研究方向。%Cadmium (Cd) is one of the major pollutants in rice grains, for rice plants can absorb Cd easily. Thus, it becomes the potential important pollutant for the food supply and food safety in China. In this review, the authors attempt to show three important steps in the bio-accumulation of Cd in rice plants, including the activation and absorption of Cd by rice roots, the loading and transportation of Cd by rice xylem, and the enrichment of Cd in rice grains by the phloem from rice internodes. The metabolic process of Cd at different rice growing stages, the control mechanism of Cd through transport protein and key genes, and the influence of environmental conditions and inputs to Cd accumulation in rice plants were discussed. The future research of Cd control mechanism in rice was also highlighted from the viewpoint of the sustainable agricultural development and the management of rice safety.

  7. Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

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    Lei Wang

    2008-06-01

    Full Text Available MODIS (Moderate Resolution Imaging Spectroradiometer is a key instrument aboard the Terra (EOS AM and Aqua (EOS PM satellites. Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers. Shaoxing county of Zhejiang Province in China was chosen to be the study site and early rice was selected as the study crop. The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day, which implies that MODIS data could be used as satellite data source for rice cultivation area estimation, possibly rice growth monitoring and yield forecasting on the regional scale.

  8. Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    MODIS (Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites.Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers.Shaoxing county of Zhcjiang Province in China was chosen to be the study site and early rice was selected as the study crop.The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day,which implies that MODIS data could be used as satellite data source for rice cultivation area estimation,possibly rice growth monitoring and yield forecasting on the regional scale.

  9. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    Directory of Open Access Journals (Sweden)

    Nadal Anna

    2012-09-01

    Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

  10. Differences between rice and wheat in temperature responses of photosynthesis and plant growth.

    Science.gov (United States)

    Nagai, Takeshi; Makino, Amane

    2009-04-01

    The temperature responses of photosynthesis (A) and growth were examined in rice and wheat grown hydroponically under day/night temperature regimes of 13/10, 19/16, 25/19, 30/24 and 37/31 degrees C. Irrespective of growth temperature, the maximal rates of A were found to be at 30-35 degrees C in rice and at 25-30 degrees C in wheat. Below 25 degrees C the rates were higher in wheat, while above 30 degrees C they were higher in rice. However, in both species, A measured at the growth temperature remained almost constant irrespective of temperature. Biomass production and relative growth rate (RGR) were greatest in rice grown at 30/24 degrees C and in wheat grown at 25/19 degrees C. Although there was no difference between the species in the optimal temperature of the leaf area ratios (LARs), the net assimilation rate (NAR) in rice decreased at low temperature (19/16 degrees C) while the NAR in wheat decreased at high temperature (37/31 degrees C). For both species, the N-use efficiency (NUE) for growth rate (GR), estimated by dividing the NAR by leaf-N content, correlated with GR and with biomass production. Similarly, when NUE for A at growth temperature was estimated, the temperature response of NUE for A was similar to that of NUE for GR in both species. The results suggest that the difference between rice and wheat in the temperature response of biomass production depends on the difference in temperature dependence of NUE for A.

  11. Influence of Rice Genotypes on Folding and Spinning Behaviour of Leaffolder (Cnaphalocrocis medinalis) and Its Interaction with Leaf Damage

    Institute of Scientific and Technical Information of China (English)

    M. PUNITHAVALLI; N. M. MUTHUKRISHNAN; M. BALAJI RAJKUMAR

    2013-01-01

    Folding and spinning behavior of Cnaphalocrocis medinalis (Guenee) (Lepidoptera:Pyralidae) in different categories of rice genotypes viz., resistant, susceptible, hybrid, scented, popular and wild rice genotypes were significantly different. Longer leaf selection time and folding time per primary fold;shorter primary fold and whole leaf fold; lower number of binds per primary fold and whole leaf fold were recorded in resistant and wild rice genotypes. In the correlation analysis, it was found that the leaf folding parameters were positively correlated to leaf folder damage whereas the leaf spinning parameters were negatively correlated. Similarly, the morphological characters differed significantly among the chosen genotypes and were related to leaffolder damage. The leaf width and total productive tiller number were positively correlated to leaffolder infestation. Results also indicated that the trichome density and length, leaf length and plant height might contribute to resistance whereas total number of green leaves had no effect on leaffolder infestation. In the scatter plot analysis between leaf folding and spinning characters and leaffolder damage, the genotypes were separated into four groups viz., resistant (TKM6, Ptb 33, LFR831311, Oryza rhizomatis and O. minuta), moderately resistant (ASD16 and CORH1), moderately susceptible (ADT36, Pusa Basmati and CB200290) and susceptible (IR36 and TN1). The present investigation proved that the leaf morphology viz., leaf length and width, plant height and trichome density and length may play a vital role in resistance against rice leaffolder.

  12. Impact of rice-straw biochars amended soil on the biological Si cycle in soil-plant ecosystem

    Science.gov (United States)

    Li, Zimin; Delvaux, Bruno; Struyf, Eric; Unzué-Belmonte, Dácil; Ronsse, Frederik; Cornelis, Jean-Thomas

    2017-04-01

    Biochar used as soil amendment can enhance soil fertility and plant growth. It may also contribute to increase the plant mineralomass of silicon (Si). However, very little studies have focused on the plant Si cycling in biochar amended soils. Here, we study the impact of two contrasting biochars derived from rice straws on soil Si availability and plant Si uptake. Rice plants were grown in a hydroponic device using Yoshida nutrient solution, respectively devoid of H4SiO4 (0 ppm Si: Si-) and enriched with it (40 ppm Si: Si+). After 12 weeks, the plants were harvested for further pyrolysis, conducted with holding time of 1h at 500˚ C. The respective rice-biochars are Si-/biochar and Si+/biochar. They exhibit contrasting phytolith contents (0.3 g Si kg-1 vs. 51.3 g Si kg-1), but identical physico-chemical properties. They were applied in two soils differing in weathering stage: a weathered Cambisol (CA) and a highly weathered Nitisol (NI). We then studied the effects of the amended biochar on CaCl2 extractable Si using a 64-days kinetic approach, on the content of soil biogenic Si, and on the uptake of Si by wheat plants grown for 5 weeks. We also quantified Si mineralomass in plants. We compared the effects of biochars to that of wollastonite (Wo)-(CaSiO3), a common Si-fertilizer. Our results show that Si+/biochar significantly increase the content of BSi in both soils. In CA, the cumulative content of CaCl2 extractable Si amounts to 85 mg kg-1 after Si+/biochar amendment, which is below the amount extracted after Wo application (100 mg kg-1). In contrast, in NI, the cumulative content of CaCl2 extractable Si is 198 mg kg-1 in the Si+/biochar amended treatment, which is far above the one measured after Wo application (93 mg kg-1). The Si-/biochar has no effect on the cumulative content of CaCl2 extractable Si in either soil type. Biochars and wollastonite increase the biomass of wheat on both soils. The increase is, however, larger in NI than in CA. In terms of Si

  13. Cloning of the Arabidopsis and Rice Formaldehyde Dehydrogenase Genes: Implications for the Origin of Plant Adh Enzymes

    Science.gov (United States)

    Dolferus, R.; Osterman, J. C.; Peacock, W. J.; Dennis, E. S.

    1997-01-01

    This article reports the cloning of the genes encoding the Arabidopsis and rice class III ADH enzymes, members of the alcohol dehydrogenase or medium chain reductase/dehydrogenase superfamily of proteins with glutathione-dependent formaldehyde dehydrogenase activity (GSH-FDH). Both genes contain eight introns in exactly the same positions, and these positions are conserved in plant ethanol-active Adh genes (class P). These data provide further evidence that plant class P genes have evolved from class III genes by gene duplication and acquisition of new substrate specificities. The position of introns and similarities in the nucleic acid and amino acid sequences of the different classes of ADH enzymes in plants and humans suggest that plant and animal class III enzymes diverged before they duplicated to give rise to plant and animal ethanol-active ADH enzymes. Plant class P ADH enzymes have gained substrate specificities and evolved promoters with different expression properties, in keeping with their metabolic function as part of the alcohol fermentation pathway. PMID:9215914

  14. Functional characterization of a pheromone-binding protein from rice leaffolder Cnaphalocrocis medinalis in detecting pheromones and host plant volatiles.

    Science.gov (United States)

    Sun, X; Zhao, Z-F; Zeng, F-F; Zhang, A; Lu, Z-X; Wang, M-Q

    2016-12-01

    Pheromone-binding proteins (PBPs) are believed to be involved in the recognition of semiochemicals. In the present study, western blot analysis, fluorescence-binding characteristics and immunolocalization of CmedPBP4 from the rice leaffolder, Cnaphalocrocis medinalis, were investigated. Western blot analysis revealed that CmedPBP4 showed obvious antenna-specific expression patterns in female and male antenna, and made a clearly different sex-biased expression. Immunocytochemical labeling revealed that CmedPBP4 showed specific expression in the trichoid sensilla. Competitive fluorescence binding assays indicated that CmedPBP4 could selectively recognize three sex pheromone components (Z13-18:Ac, Z11-16:Al and Z13-18:OH) and eleven rice plant volatiles, including cyclohexanol, nerolidol, cedrol, dodecanal, ionone, (-)-α-cedrene, (Z)-farnesene, β-myrcene, R-(+)-limonene, (-)-limonene, and (+)-3-carene. Meanwhile the CmedPBP4 detection of sex pheromones and host odorants was pH-dependent. Our results, for the first time, provide further evidence that trichoid sensilla might be play an important role in detecting sex pheromones and host plant volatiles in the C. medinalis moth. Our systematic studies provided further detailed evidence for the function of trichoid sensilla in insect semiochemical perception.

  15. Role of peroxidases in the compensation of cytosolic ascorbate peroxidase knockdown in rice plants under abiotic stress.

    Science.gov (United States)

    Bonifacio, Aurenivia; Martins, Marcio O; Ribeiro, Carolina W; Fontenele, Adilton V; Carvalho, Fabricio E L; Margis-Pinheiro, Márcia; Silveira, Joaquim A G

    2011-10-01

    Current studies, particularly in Arabidopsis, have demonstrated that mutants deficient in cytosolic ascorbate peroxidases (APXs) are susceptible to the oxidative damage induced by abiotic stress. In contrast, we demonstrate here that rice mutants double silenced for cytosolic APXs (APx1/2s) up-regulated other peroxidases, making the mutants able to cope with abiotic stress, such as salt, heat, high light and methyl viologen, similar to non-transformed (NT) plants. The APx1/2s mutants exhibited an altered redox homeostasis, as indicated by increased levels of H₂O₂ and ascorbate and glutathione redox states. Both mutant and NT plants exhibited similar photosynthesis (CO₂) assimilation and photochemical efficiency) under both normal and stress conditions. Overall, the antioxidative compensatory mechanism displayed by the mutants was associated with increased expression of OsGpx genes, which resulted in higher glutathione peroxidase (GPX) activity in the cytosolic and chloroplastic fractions. The transcript levels of OsCatA and OsCatB and the activities of catalase (CAT) and guaiacol peroxidase (GPOD; type III peroxidases) were also up-regulated. None of the six studied isoforms of OsApx were up-regulated under normal growth conditions. Therefore, the deficiency in cytosolic APXs was effectively compensated for by up-regulation of other peroxidases. We propose that signalling mechanisms triggered in rice mutants could be distinct from those proposed for Arabidopsis.

  16. CONFIGURATION OF CULTURAL NORMS IN TRADITIONAL RICE PLANTING RITUAL DISCOURSE THE TRADITIONAL FARMING COMMUNITY OF BAYAN, NORTH LOMBOK

    Directory of Open Access Journals (Sweden)

    I Made Netra

    2015-01-01

    Full Text Available This is the study of traditional rice planting ritual discourse of the traditional farming community of Bayan, North Lombok in an ethno-pragmatic perspective.  It is specifically aimed at describing the cultural norms and their meaning configurations.  The theory used in the study is the cultural scripts developed by Wierzbicka (2002a considering that cultural norms constitute rules and regulations in social interaction practices. They can be investigated from the use of grammatical aspects of language and linguistic routines which are context-bound. They can be configured by paraphrasing in simple and mini language using single space. The results of the study showed that there were some cultural norms found on the traditional rice planting ritual discourse of the traditional farming community of Bayan, North Lombok. They included: (1 asserting thought and hope, (2 respecting other entities, (3 apologizing, (4 promising, and (5 giving advice. The configuration of these cultural norms was in accordance with the understanding of local cultural scripts and wisdom in terms of rituals of the local farming system. The configuration is constructed in low-level script with components of “when” and “if”. It contains the aspects of thinking, speaking, and doing. It is derived from the semantic primes of both evaluation and perception.

  17. Little white lies: pericarp color provides insights into the origins and evolution of Southeast Asian weedy rice

    Science.gov (United States)

    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy ...

  18. Mexican rice borer (Lepidoptera: Crambidae) injury to corn greater than to sorghum and sugarcane under field conditions.

    Science.gov (United States)

    Showler, Allan T; Wilson, Blake E; Reagan, Thomas E

    2012-10-01

    The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is the key pest of sugarcane (Saccharum spp.) in Texas; it can attack several grassy crop and noncrop host plants and has spread into Louisiana. Through small-plot, commercial field, and pheromone trap experiments, this study demonstrates that the pest uses corn, Zea mays L., more than sugarcane and sorghum, Sorghum bicolor (L.) Moench, but when corn is harvested in late summer, injury to nearby sugarcane strongly increases during the next approximately equal to 2 mo to harvest. Corn was more infested than sugarcane and sorghum in commercial fields regardless of whether sampling occurred on field edges or farther into field interiors. Differences in numbers of infested stalks and in numbers of larval entry holes between field edges and interiors were not detected. We found that Mexican rice borer infestation of corn can cause loss of ears, and lodging, shattering, and complete destruction of maturing stalks. The larger quantities of adult Mexican rice borers captured in pheromone-based traps placed at corn field edges compared with sorghum and sugarcane field edges further indicates that corn is preferred to sugarcane and sorghum. The basis for the pest's attraction to corn and implications to potential range expansion to other U.S. sugarcane-growing regions are discussed.

  19. Influence of nitrogen loading and plant nitrogen assimilation on nitrogen leaching and N₂O emission in forage rice paddy fields fertilized with liquid cattle waste.

    Science.gov (United States)

    Riya, Shohei; Zhou, Sheng; Kobara, Yuso; Sagehashi, Masaki; Terada, Akihiko; Hosomi, Masaaki

    2015-04-01

    Livestock wastewater disposal onto rice paddy fields is a cost- and labor-effective way to treat wastewater and cultivate rice crops. We evaluated the influence of nitrogen loading rates on nitrogen assimilation by rice plants and on nitrogen losses (leaching and N2O emission) in forage rice fields receiving liquid cattle waste (LCW). Four forage rice fields were subjected to nitrogen loads of 107, 258, 522, and 786 kg N ha(-1) (N100, N250, N500, and N750, respectively) using basal fertilizer (chemical fertilizer) (50 kg N ha(-1)) and three LCW topdressings (each 57-284 kg N ha(-1)). Nitrogen assimilated by rice plants increased over time. However, after the third topdressing, the nitrogen content of the biomass did not increase in any treatment. Harvested aboveground biomass contained 93, 60, 33, and 31 % of applied nitrogen in N100, N250, N500, and N750, respectively. The NH4 (+) concentration in the pore water at a depth of 20 cm was less than 1 mg N L(-1) in N100, N250, and N500 throughout the cultivation period, while the NH4 (+) concentration in N750 increased to 3 mg N L(-1) after the third topdressing. Cumulative N2O emissions ranged from -0.042 to 2.39 kg N ha(-1); the highest value was observed in N750, followed by N500. In N750, N2O emitted during the final drainage accounted for 80 % of cumulative N2O emissions. This study suggested that 100-258 kg N ha(-1) is a recommended nitrogen loading rate for nitrogen recovery by rice plants without negative environmental impacts such as groundwater pollution and N2O emission.

  20. Rice hull mulch affects germination of bittercress and creeping woodsorrel in container plant culture

    Science.gov (United States)

    Mulches are commonly used to control weeds in container nursery crops, especially in sites where preemergence herbicides are either not labeled or potentially phytotoxic to the crop. Parboiled rice hulls have been shown to provide effective weed control when applied 1.25 to 2.5 cm deep over the con...

  1. Differences between Rice Cultivars in Iron Plaque Formation on Roots and Plant Lead Tolerance

    Directory of Open Access Journals (Sweden)

    Xinmei Ma

    2013-02-01

    Full Text Available The aim of this study was to understand some mechanisms on the variations between rice cultivars in lead (Pb tolerance. Pot soil experiments were conducted with two rice cultivars under different soil Pb levels and the relationships between Pb phytotoxicity, uptake and iron plaque formation on roots were investigated. The results showed that the rice cultivar with indica consanguinity (Shanyou 63 were more sensitive to soil Pb stress than the cultivar with japonica consanguinity (Wuyunjing 7, particularly for the roots. Pb concentrations and distribution ratios in root tissues were higher for Shan you 63 than for Wuyunjing 7, but those in the plaques showed a reverse order. Fe distribution ratios in plaques were also larger for Wuyunjing 7 than for Shanyou 63, but the ratios in root tissues showed a reverse order. The results indicate that iron plaque formation on rice roots can provide a barrier to soil Pb stress in Pb-contaminated soils. The plaque will increase the sequestration of Pb on root surface, providing a means of external exclusion of soil Pb. But the function of the plaque is limited, only effective in relatively lower or moderate levels of soil Pb contamination.

  2. Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.

  3. Road of Introducing Rice Planting into Japan and Zhoushan Archipelago%稻作东传之路与舟山群岛

    Institute of Scientific and Technical Information of China (English)

    陶和平

    2000-01-01

    The rice planting in Japan was introduced from ancient China. It seems to be most possible for rice planting to be introduced into Japan directly from the mouths of Changjiang River and Qiantang River among the various lines of introducing rice planting into Japan which are being discussed in the Chinese and Japanese studies. And Zhoushan Archipelago, with its favorable conditions of peculiar geographical position, oceanic current, climate and transport, played a role of relay station and "springboard" in the introduction of Chinese rice-planting culture into Japan. The introduction of rice planting into Japan, however, cannot rule out its contingency.%日本的水稻种植由古代中国传入。中日学者在论述稻作东传的诸多路线,似以长江口与钱塘江口直接东传的可能性最大。而舟山群岛由于其独特的地理位置、洋流、气候与交通诸条件,对中国稻作文化东传日本起到了中继站与“跳板”的作用。但稻作东传也不能排除其偶然性因素。

  4. Heavy metal contaminations in soil-rice system: source identification in relation to a sulfur-rich coal burning power plant in Northern Guangdong Province, China.

    Science.gov (United States)

    Wang, Xiangqin; Zeng, Xiaoduo; Chuanping, Liu; Li, Fangbai; Xu, Xianghua; Lv, Yahui

    2016-08-01

    Heavy metal contents (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in 99 pairs of soil-rice plant samples were evaluated from the downwind directions of a large thermal power plant in Shaoguan City, Guangdong Province, China. Results indicate that there is a substantial buildup of As, Cd, Cu, Pb, and Zn in the predominant wind direction of the power plant. The significant correlations between S and heavy metals in paddy soil suggest that the power plant represents a source of topsoil heavy metals in Shaoguan City due to sulfur-rich coal burning emissions. Elevated Cd concentrations were also found in rice plant tissues. Average Cd (0.69 mg kg(-1)) and Pb (0.39 mg kg(-1)) contents in rice grain had exceeded their maximum permissible limits (both were 0.2 mg kg(-1)) in foods of China (GB2762-2005). The enrichment of Cd and Pb in rice grain might pose a potential health risk to the local residents.

  5. Expression profiling of two stress-inducible genes encoding for miraculin-like proteins in citrus plants under insect infestation or salinity stress.

    Science.gov (United States)

    Podda, A; Simili, M; Del Carratore, R; Mouhaya, W; Morillon, R; Maserti, B E

    2014-01-01

    The expression of two genes, namely Mir1 and Mir3 and the abundance of their encoded proteins, the putative miraculin-like proteins, MLP1 and MLP3, showing similarity to the Kunitz family of protease inhibitors, were monitored in the leaves of the citrus variety, 'Clementine' after Tetranychus urticae infestation and elicitor treatments, or in the leaves of three other diploid citrus: 'Willow leaf', 'Cleopatra' mandarins and 'Trifoliate' orange, as well as their respective doubled diploids and the allotetraploid somatic hybrid 'FLHORAG1' under salt stress. RT-PCR and 2-DE indicated that Mir1 and Mir3 and their products were present at low-basal expression in all citrus genotypes. Both genes and products were induced in the 'Clementine' leaves infested by T. urticae, but a contrasting profile was observed under elicitor treatments. Under salt stress, the two genes showed an expression pattern contrasting each other and depending on the genotypes. 'Cleopatra' mandarin, 'Trifoliate' orange and 'FLHORAG1' presented overexpression of Mir3 and MLP3 and decreased levels of Mir1 and MPL1. The opposite behaviour was found in 'Willow leaf' mandarin. The positive correlation of the expression profile of the two genes with that of a gene encoding a putative apoplastic cysteine protease (CysP) might suggest a possible interaction of the respective encoded proteins during the response to biotic stress. Under salt stress, CysP and Mir 1 showed a similar expression pattern but only at transcript level. The possible occurrence of post-translational CysP regulation is discussed.

  6. Plant growth-promoting traits of epiphytic and endophytic yeasts isolated from rice and sugar cane leaves in Thailand.

    Science.gov (United States)

    Nutaratat, Pumin; Srisuk, Nantana; Arunrattiyakorn, Panarat; Limtong, Savitree

    2014-08-01

    A total of 1035 yeast isolates, obtained from rice and sugar cane leaves, were screened primarily for indole-3-acetic acid (IAA) production. Thirteen isolates were selected, due to their IAA production ranging from 1.2 to 29.3 mg g(-)(1) DCW. These isolates were investigated for their capabilities of calcium phosphate and ZnO(3) solubilisation, and also for production of NH(3), polyamine, and siderophore. Their 1-aminocyclopropane-1-carboxylate (ACC) deaminase, catalase and fungal cell wall-degrading enzyme activities were assessed. Their antagonism against rice fungal pathogens was also evaluated. Strain identification, based on molecular taxonomy, of the thirteen yeast isolates revealed that four yeast species - i.e. Hannaella sinensis (DMKU-RP45), Cryptococcus flavus (DMKU-RE12, DMKU-RE19, DMKU-RE67, and DMKU-RP128), Rhodosporidium paludigenum (DMKU-RP301) and Torulaspora globosa (DMKU-RP31) - were capable of high IAA production. Catalase activity was detected in all yeast strains tested. The yeast R. paludigenum DMKU-RP301 was the best IAA producer, yielding 29.3 mg g(-)(1) DCW, and showed the ability to produce NH3 and siderophore. Different levels of IAA production (7.2-9.7 mg g(-)(1) DCW) were found in four strains of C. flavus DMKU-RE12, DMKU-RE19, and DMKU-RE67, which are rice leaf endophytes, and strain DMKU-RP128, which is a rice leaf epiphyte. NH(3) production and carboxymethyl cellulase (CMCase) activity was also detected in these four strains. Antagonism to fungal plant pathogens and production of antifungal volatile compounds were exhibited in T. globosa DMKU-RP31, as well as a moderate level of IAA production (4.9 mg g(-)(1) DCW). The overall results indicated that T. globosa DMKU-RP31 might be used in two ways: enhancing plant growth and acting as a biocontrol agent. In addition, four C. flavus were also found to be strains of interest for optimal IAA production.

  7. Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

    Directory of Open Access Journals (Sweden)

    Kazi Md Kamrul Huda

    Full Text Available BACKGROUND: Plasma membrane Ca(2+ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+ from the cell, hence regulating Ca(2+ level within cells. Though plant Ca(2+ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied. RESULTS: The 1478 bp promoter sequence of rice plasma membrane Ca(2+ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs. CONCLUSIONS: The rice plasma membrane Ca(2+ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the

  8. Characterization of QTL for unique agronomic traits of new-plant-type rice varieties using introgression lines of IR64

    Directory of Open Access Journals (Sweden)

    Analiza G. Tagle

    2016-02-01

    Full Text Available To enhance the yield potential of an elite indica rice cultivar, an introgression (BC3-derived line of IR64, YTH288, was developed using a new-plant-type cultivar, IR66215-44-2-3, as a donor parent. YTH288 has agronomically valuable characteristics such as large panicles, few unproductive tillers, and large leaves inherited from NPT. To identify the genetic basis of these traits, we used 167 F2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits: days to heading (DTH, culm length (CL, flag leaf length (FLL, flag leaf width (FLW, and filled spikelet number per panicle (FSN. Six putative QTL were detected: four on chromosome 4 (for CL, FLL, FLW, and FSN and two on chromosome 2 (for DTH and FLL. All QTL with the IR66215-44-2-3 allele, except that for FLL on chromosome 2, had positive effects on each trait. To confirm the effects of these putative QTL, we developed NILs with the IR64 genetic background by marker-assisted selection. We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes 2 and 4. Additionally, four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropic effects for unique agronomic traits. These NILs can be used as research materials for studying each trait and as breeding materials for yield improvement of indica rice cultivars. Abbreviations NPT, new plant type; QTL, quantitative trait loci (locus; GF, grain fertility; DTH, days to heading; CL, culm length; PL, panicle length; LL, leaf length; FLL, flag leaf length; LW, leaf width; FLW, flag leaf width; FSN, filled spikelet number per panicle; TSN, total spikelet number per panicle; PN, panicle number per plant; IRRI, International Rice Research Institute; NIL, near-isogenic line; IL, introgression line; SSR, simple sequence repeat; PCR, polymerase chain reaction

  9. Responses of Rapid Viscoanalyzer Profile and Other Rice Grain Qualities to Exogenously Applied Plant Growth Regulators under High Day and High Night Temperatures.

    Science.gov (United States)

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Hassan, Shah; Chauhan, Bhagirath Singh; Khan, Fahad; Ihsan, Muhammad Zahid; Ullah, Abid; Wu, Chao; Bajwa, Ali Ahsan; Alharby, Hesham; Amanullah; Nasim, Wajid; Shahzad, Babar; Tanveer, Mohsin; Huang, Jianliang

    2016-01-01

    High-temperature stress degrades the grain quality of rice; nevertheless, the exogenous application of plant growth regulators (PGRs) might alleviate the negative effects of high temperatures. In the present study, we investigated the responses of rice grain quality to exogenously applied PGRs under high day temperatures (HDT) and high night temperatures (HNT) under controlled conditions. Four different combinations of ascorbic acid (Vc), alpha-tocopherol (Ve), brassinosteroids (Br), methyl jasmonates (MeJA) and triazoles (Tr) were exogenously applied to two rice cultivars (IR-64 and Huanghuazhan) prior to the high-temperature treatment. A Nothing applied Control (NAC) was included for comparison. The results demonstrated that high-temperature stress was detrimental for grain appearance and milling qualities and that both HDT and HNT reduced the grain length, grain width, grain area, head rice percentage and milled rice percentage but increased the chalkiness percentage and percent area of endosperm chalkiness in both cultivars compared with ambient temperature (AT). Significantly higher grain breakdown, set back, consistence viscosity and gelatinization temperature, and significantly lower peak, trough and final viscosities were observed under high-temperature stress compared with AT. Thus, HNT was more devastating for grain quality than HDT. The exogenous application of PGRs ameliorated the adverse effects of high temperature in both rice cultivars, and Vc+Ve+MejA+Br was the best combination for both cultivars under high temperature stress.

  10. Effects of mercury contaminated rice from typical chemical plant area in China on nitric oxide changes and c-fos expression of rats brain

    Institute of Scientific and Technical Information of China (English)

    CHENG Jin-ping; WANG Wen-hua; JIA Jin-ping; HU Wei-xuan; SHI Wei; Lin Xue-yu

    2005-01-01

    China is one of countries with the highest mercury production in the world. The Guizhou Province in Southwestern China is currently one of the world's most important mercury production areas. In order to study the neurotoxicity of rice from Qingzhen Chemical Plant area and probe into the signal transduction molecular mechanism of injury in rat brain stimulation by mercury contaminated rice. The rats were exposed to mercury contaminated rice for 20 d. Both of the measurements of NO and NOS were processed according to the protocol of the kit. The effect of Hg contaminated rice on the expression of c-fos mRNA in rat brain and the expression of c-FOS protein in cortex, hippocampus were observed using reverse transcription polymerase chain reaction(RT-PCR) and immunocytochemical methods.The results showed the neural transmitter NO and NOS in brain were significantly change between exposure groups and control group; the mercury polluted rice induced significantly the expression of c-fos mRNA; the c-FOS positive cells in hippocampus and cortex of exposure groups were significant different from control group( p < 0.01). It could be concluded that nitric oxide was involved in mercury contaminated rice induced immediate early gene c-fos expressions in the rat brain. Through food chain, local ecosystem and health of local people iave been deteriorated seriously by mercury. This serious situation will last a long period. In order to alleviate mercury pollution, more work needs to do.

  11. Weed infestation of onion in soil reduced cultivation system

    Directory of Open Access Journals (Sweden)

    Marzena Błażej-Woźniak

    2013-12-01

    Full Text Available Field experiment was conducted in the years 1998-2000 in GD Felin. The influence of no-tillage cultivation and conventional tillage with spring ploughing on weed infestation of onion was compared. In experiment four cover crop mulches (Sinapis alba L., Vicia sativa L., Phacelia tanacetifolia B., Avena sativa L. were applied. From annual weeds in weed infestation of onion in great number Matricaria chamomilla L., and Senecio vulgaris L. stepped out. and from perennial - Agropyron repens (L.P.B. Reduced soil cultivation system (no-tillage caused the significant growth of primary weed infestation of onion in comparison with conventional tillage. In all years of investigations the executed pre-sowing ploughing limited significantly the annual weeds' number in primary weed infestation. The applied mulches from cover plants limited in considerable degree the number of primary weed infestation. In all years of investigations the most weeds stepped out on control object. Among investigated cover crop mulches Vicia sativa L. and Avena sativa L. had a profitable effect on decrease of onion`s primary weed infestation. Soil cultivation system and cover crop mulches had no signi ficant residual influence on the secondary weed infestation of onion.

  12. Cyanide, a Coproduct of Plant Hormone Ethylene Biosynthesis, Contributes to the Resistance of Rice to Blast Fungus1[W][OA

    Science.gov (United States)

    Seo, Shigemi; Mitsuhara, Ichiro; Feng, Jiao; Iwai, Takayoshi; Hasegawa, Morifumi; Ohashi, Yuko

    2011-01-01

    Rice (Oryza sativa) plants carrying the Pi-i resistance gene to blast fungus Magnaporthe oryzae restrict invaded fungus in infected tissue via hypersensitive reaction or response (HR), which is accompanied by rapid ethylene production and formation of small HR lesions. Ethylene biosynthesis has been implicated to be important for blast resistance; however, the individual roles of ethylene and cyanide, which are produced from the precursor 1-aminocyclopropane-1-carboxylic acid, remain unevaluated. In this study, we found that Pi-i-mediated resistance was compromised in transgenic rice lines, in which ethylene biosynthetic enzyme genes were silenced and then ethylene production was inhibited. The compromised resistance in transgenic lines was recovered by exogenously applying cyanide but not ethephon, an ethylene-releasing chemical in plant tissue. In a susceptible rice cultivar, treatment with cyanide or 1-aminocyclopropane-1-carboxylic acid induced the resistance to blast fungus in a dose-dependent manner, while ethephon did not have the effect. Cyanide inhibited the growth of blast fungus in vitro and in planta, and application of flavonoids, secondary metabolites that exist ubiquitously in the plant kingdom, enhanced the cyanide-induced inhibition of fungal growth. These results suggested that cyanide, whose production is triggered by HR in infected tissue, contributes to the resistance in rice plants via restriction of fungal growth. PMID:21075959

  13. Assessing green-processing technologies for wet milling freshly hulled and germinated brown rice, leading to naturally fortified plant-based beverages

    Science.gov (United States)

    Rice milk beverages can well balanced nutrition. With healthier nutrition in consumer’s minds, national. Worldwide consumption/production of plant-based milk beverages are increasing. Much past research and invention was based on enzymatic conversion processes for starch that were uncomplicated be...

  14. Polyamines as biomarkers for plant regeneration capacity: improvement of regeneration by modulation of polyamine metabolism in different genotypes of indica rice.

    Science.gov (United States)

    Shoeb, F; Yadav, J S.; Bajaj, S; Rajam, M V.

    2001-05-01

    The importance of cellular polyamine (PA) levels and the ratio of putrescine (Put) to spermidine (Spd) for plant regeneration ability via somatic embryogenesis in several commercially grown indica rice varieties is reported here. The genotypes namely NDR-624, IR-20, IR-36, BJ-1 (having Put:Spd ratio approximately 2.3) showed superior plant regeneration while KL, PB-1 and TN-1 (having Put:Spd ratio approximately 3.8) showed moderate plant regeneration ability. The genotypes namely HS, Bindli, DV-85, ACB-72, IR-64 and IR-72 (having Put:Spd ratio approximately 5.0) showed poor plant regeneration ability. In contrast KH-7 (Put:Spd ratio approximately 10.0) showed no response at all. Favorable modification of cellular PA titers and their Put:Spd ratio by the addition of exogenous PAs (Put, Spd) or their biosynthesis inhibitor, difluoromethylarginine (DFMA) led to the induction/promotion of plant regeneration in poorly responding genotypes. These results showed a close relationship between cellular PA levels and their Put:Spd ratio with in vitro morphogenetic capacity in indica rice and suggest that the cellular PAs and Put:Spd ratios are important determinants (biomarkers) of plant regeneration ability in indica rice, and the improvement/induction of plant regeneration in morphogenetically poor and recalcitrant species could be achieved by modulating PA metabolism.

  15. Dynamics of seed-borne rice endophytes on early plant growth stages

    NARCIS (Netherlands)

    Hardoim, Pablo R.; Hardoim, Cristiane C. P.; van Overbeek, Leonard S.; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However,

  16. Dynamics of Seed-Borne Rice Endophytes on Early Plant Growth Stages

    NARCIS (Netherlands)

    Hardoim, P.R.; Hardoim, C.C.P.; Overbeek, van L.S.; Elsas, van J.D.

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However,

  17. Effects of nitrogen form on growth,CO2 assimilation,chlorophyll fluorescence,and photosynthetic electron allocation in cucumber and rice plants

    Institute of Scientific and Technical Information of China (English)

    Yan-hong ZHOU; Yi-li ZHANG; Xue-min WANG; Jin-xia CUI; Xiao-jian XIA; Kai SHI; Jing-quan YU

    2011-01-01

    Cucumber and rice plants with varying ammonium(NH4+)sensitivities were used to examine the effects of different nitrogen(N)sources on gas exchange,chlorophyll(ChI)fluorescence quenching,and photosynthetic electron allocation.Compared to nitrate(NO3-)-grown plants,cucumber plants grown under NH4+-nutdtion showed decreased plant growth,net photosynthetic rate,stomatal conductance,intercellular carbon dioxide(CO2)level,transpiration rate,maximum photochemical efficiency of photosystem Ⅱ,and O2-independent alternative electron flux,and increased O2-dependent alternative electron flux.However,the N source had little effect on gas exchange,ChI a fluorescence parameters,and photosynthetic electron allocation in rice plants,except that NH4+-grown plants had a higher O2-independent alternative electron flux than NO3--grown plants.NO3-reduction activity was rarely detected in leaves of NH4+-grown cucumber plants,but was high in NH4+-grown rice plants.These results demonstrate that significant amounts of photosynthetic electron transport were coupled to NO3-assimilation,an effect more significant in NO3--grown plants than in NH4+-grown plants.Meanwhile,NH4+-tolerant plants exhibited a higher demand for the reduced form of nicotinamide adenine dinucleotide phosphate(NADPH)for NO3-reduction,regardless of the N form supplied,while NH4+-sensitive plants had a high water-water cycle activity when NH4+was supplied as the sole N source.

  18. Use of Linear Spectral Mixture Model to Estimate