WorldWideScience

Sample records for high-amylose rice resistant

  1. Resistant Starch: Variation among High Amylose Rice Varieties and Its Relationship with Apparent Amylose Content, Pasting Properties and Cooking Methods

    Science.gov (United States)

    Resistant starch (RS), which is not hydrolyzed in the small intestines, has proposed health benefits. We evaluated a set of 40 high amylose rice varieties for RS levels in cooked rice and approximately a 1.9-fold difference was found. The highest ones had more than two-fold greater RS concentration ...

  2. High Amylose White Rice Reduces Post-Prandial Glycemic Response but Not Appetite in Humans

    Directory of Open Access Journals (Sweden)

    Alison M. Zenel

    2015-07-01

    Full Text Available The present study compared the effects of three rice cultivars on postprandial glycemic control and appetite. A single-blind, randomized, crossover clinical trial was performed with 18 healthy subjects, nine males and nine females. Three treatments were administered at three separate study visits: commercially available conventional white rice (short grain, specialty high amylose white rice 1 (Dixiebelle, and specialty high amylose white rice 2 (Rondo. Postprandial capillary blood glucose, venous blood glucose and insulin measurements, and appetite visual analog scale (VAS surveys were done over the course of two hours. The capillary blood glucose concentrations were significantly lower for Rondo compared to short grain rice at 30 min, and for Dixiebelle and Rondo compared to short grain rice at 45, 60, and 120 min. Capillary blood glucose area under the curve (AUC was significantly lower for Dixiebelle and Rondo compared to short grain rice. Subjects were significantly more hungry at 30 min after Dixiebelle intake than Rondo intake, but there were no other significant effects in appetite ratings. The present study determined that intake of high amylose rice with resistant starch (RS can attenuate postprandial blood glucose and insulin response in comparison to short grain rice.

  3. Particle size fractionation of high-amylose rice (Goami 2) flour as an oil barrier in a batter-coated fried system

    Science.gov (United States)

    The particle size effects of high-amylose rice (Goami 2) flour on quality attributes of frying batters were characterized in terms of physicochemical, rheological, and oil-resisting properties. High-amylose rice flours were fractionated into four fractions (70, 198, 256, and 415 µm) of which morpho...

  4. Structural and functional properties of alkali-treated high-amylose rice starch.

    Science.gov (United States)

    Cai, Jinwen; Yang, Yang; Man, Jianmin; Huang, Jun; Wang, Zhifeng; Zhang, Changquan; Gu, Minghong; Liu, Qiaoquan; Wei, Cunxu

    2014-02-15

    Native starches were isolated from mature grains of high-amylose transgenic rice TRS and its wild-type rice TQ and treated with 0.1% and 0.4% NaOH for 7 and 14 days at 35 °C. Alkali-treated starches were characterised for structural and functional properties using various physical methods. The 0.1% NaOH treatment had no significant effect on structural and functional properties of starches except that it markedly increased the hydrolysis of starch by amylolytic enzymes. The 0.4% NaOH treatment resulted in some changes in structural and functional properties of starches. The alkali treatment affected granule morphology and decreased the electron density between crystalline and amorphous lamellae of starch. The effect of alkali on the crystalline structure including long- and short-range ordered structure was not pronounced. Compared with control starch, alkali-treated TRS starches had lower amylose content, higher onset and peak gelatinisation temperatures, and faster hydrolysis of starch by HCl and amylolytic enzymes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Sensory characteristics of high-amylose maize-resistant starch in three food products

    OpenAIRE

    Maziarz, Mindy; Sherrard, Melanie; Juma, Shanil; Prasad, Chandan; Imrhan, Victorine; Vijayagopal, Parakat

    2012-01-01

    Type 2 resistant starch from high-amylose maize (HAM-RS2) is considered a functional ingredient due to its positive organoleptic and physiochemical modifications associated with food and physiological benefits related to human health. The sensory characteristics of three types of food products (muffins, focaccia bread, and chicken curry) with and without HAM-RS2 were evaluated using a 9-point hedonic scale. The HAM-RS2-enriched muffins, focaccia bread, and chicken curry contained 5.50 g/100 g...

  6. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nosratola D Vaziri

    Full Text Available Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control or high fermentable fiber (amylose maize resistant starch, HAM-RS2 for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  7. ¬¬OPTIMASI PENGGUNAAN HIDROKOLOID TERHADAP PASTA MAKARONI BERBASIS BERAS BERAMILOSA TINGGI [Hydrocolloid Optimization on Maccaroni Pasta from High Amylose Rice

    Directory of Open Access Journals (Sweden)

    Eko Hari Purnomo

    2015-12-01

    Full Text Available Pasta is an extrusion product which is commonly produced from wheat flour. Gluten is key substance of wheat flour that affect quality of pasta, such as low cooking loss, low adhesiveness and firm pasta structure. However, gluten may cause health problem for consumers with celiac disease or gluten intolerance. Rice is safe for celiac disease sufferer, but it is technologically challenging to develop rice-based pasta. The objective of this research was to evaluate the effect of different ratio between xanthan gum and guar gum (2% on the physical characteristics of macaroni pasta from rice flour. This research consisted of several steps which include flour milling and characterization, formulation, and final product analysis. The result showed that different ratio of xanthan gum and guar gum had significant effect to cooking loss, adhesiveness, springiness and hue parameters (P0.05. The optimum formula was noodle by hydrocolloid ratio 2% of xanthan gum and 0 % of guar gum which had desirability value of 0.798. The selected formula was organoleptically accepted by panelists and containing 9.84 % of water, 1.65% of ash, 12.05% of protein, 1.41% of fat, 75.05% of carbohydrate, 24.49% of amylose, also 33.49 "μm" of pore size.

  8. Apparent mineral retention is similar in control and hyperinsulinemic men after consumption of high amylose cornstarch.

    Science.gov (United States)

    Behall, Kay M; Howe, Juliette C; Anderson, Richard A

    2002-07-01

    The effects on apparent mineral retention after long-term consumption of a high amylose diet containing 30 g resistant starch (RS) were investigated in 10 control and 14 hyperinsulinemic men. Subjects consumed products (bread, muffins, cookies, corn flakes and cheese puffs) made with standard (70% amylopectin, 30% amylose; AP) or high amylose (70% amylose, 30% amylopectin; AM) cornstarch for two 14-wk periods in a crossover pattern. Starch products replaced usual starches in the habitual diet for 10 wk followed by 4 wk of consuming the controlled diets. During wk 12, all urine, feces and duplicate foods were collected for 7 d. Urinary chromium losses after a glucose tolerance test or 24-h collections of the hyperinsulinemic and control subjects did not differ and were not altered by diet. Except for zinc, the two subject types did not differ significantly in apparent mineral balance. Apparent retentions of calcium and magnesium were not significantly affected by diet (AM vs. AP) or type-by-diet interaction. Apparent iron retention tended to be greater after AM than AP consumption (P copper retention was greater after consuming AP than after AM (P < 0.02), whereas apparent zinc retention was greater after consuming AM than after AP (P < 0.018). Zinc also showed a significant type-by-diet interaction (P < 0.034) with control subjects retaining less zinc after consuming AP than after AM. In summary, a high amylose cornstarch diet containing 30 g RS could be consumed long term without markedly affecting, and possibly enhancing, retention of some minerals.

  9. Effect of parboiling on the formation of resistant starch, digestibility and functional properties of rice flour from different varieties grown in Sri Lanka.

    Science.gov (United States)

    Gunaratne, Anil; Kao, Wu; Ratnayaka, Jennet; Collado, Lilia; Corke, Harold

    2013-08-30

    Hydrothermal treatment used in parboiling could induce formation of novel starch properties having potential food applications. In the current work, functional, digestible and retrogradation properties of flour from non-parboiled and steamed parboiled six rice varieties with high amylose content of around 30% but differing in length and width ratio were investigated and compared. The parboiling process reduced swelling volume and amylose leaching in all tested varieties. Among the varieties studied, the resistant starch content ranged from 1.6% in AT 306 to 0.46% in BG 357. Parboiling reduced the resistant starch content in AT 306 by about 50%, but it did not significantly affect the resistant starch content of the other varieties. The amylose-lipid complex remained unchanged after parboiling. Amylopectin retrogradation was not observed in parboiled rice. Amylose retrogradation was not seen except for AT 306. Pasting behaviour of parboiled rice flours showed high pasting stability and low setback. Flours were more susceptible to enzymatic hydrolysis after parboiling. Partial gelatinisation during parboiling was sufficient to produce grains with excellent milling quality showing a head rice recovery that ranged from 98% to 100% among the varieties studied. Degree of gelatinisation is the most important factor that determines the high head rice recovery. High pasting stability and low setback of flour of parboiled rice indicate some potential food applications. © 2013 Society of Chemical Industry.

  10. Production of high-amylose maize lines using RNA interference in ...

    African Journals Online (AJOL)

    amylose maize lines with a low T-DNA copy number, demonstrating that RNAi is an efficient method for the production of high-amylose maize lines. Key words: Maize, high-amylose, RNA interference, starch branching enzyme gene sbe2a.

  11. Compressive Load Resistance Characteristics of Rice Grain

    OpenAIRE

    Sumpun Chaitep; Chaiy R. Metha Pathawee; Pipatpong Watanawanyoo

    2008-01-01

    Investigation was made to observe the compressive load property of rice gain both rough rice and brown grain. Six rice varieties (indica and japonica) were examined with the moisture content at 10-12%. A compressive load with reference to a principal axis normal to the thickness of the grain were conducted at selected inclined angles of 0°, 15°, 30°, 45°, 60° and 70°. The result showed the compressive load resistance of rice grain based on its characteristic of yield s...

  12. Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch

    CSIR Research Space (South Africa)

    Wokadala, OC

    2014-06-01

    Full Text Available In this study, waxy and high amylose starches were modified through butyl-etherification to facilitatecompatibility with polylactide (PLA). Fourier transform infrared spectroscopy, proton nuclear magneticresonance spectroscopy and wettability tests...

  13. Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch.

    Science.gov (United States)

    Wokadala, Obiro Cuthbert; Emmambux, Naushad Mohammad; Ray, Suprakas Sinha

    2014-11-04

    In this study, waxy and high amylose starches were modified through butyl-etherification to facilitate compatibility with polylactide (PLA). Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and wettability tests showed that hydrophobic butyl-etherified waxy and high amylose starches were obtained with degree of substitution values of 2.0 and 2.1, respectively. Differential scanning calorimetry, tensile testing, and scanning electron microscopy (SEM) demonstrated improved PLA/starch compatibility for both waxy and high amylose starch after butyl-etherification. The PLA/butyl-etherified waxy and high amylose starch composite films had higher tensile strength and elongation at break compared to PLA/non-butyl-etherified composite films. The morphological study using SEM showed that PLA/butyl-etherified waxy starch composites had a more homogenous microstructure compared to PLA/butyl-etherified high amylose starch composites. Thermogravimetric analysis showed that PLA/starch composite thermal stability decreased with starch butyl-etherification for both waxy and high amylose starches. This study mainly demonstrates that PLA/starch compatibility can be improved through starch butyl-etherification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Induced mutation for tungro resistance in rice

    International Nuclear Information System (INIS)

    Ikeda, R.; Yumol, R.R.; Taura, S.

    2001-01-01

    Tungro is the most serious virus disease of rice in South and Southeast Asia. It is a composite disease of two kinds of viruses, rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). Damage to the plant is mostly caused by RTBV, while RTSV acts to facilitate RTBV acquisition and transmission by insect vector. Both viruses are transmitted mainly by green leafhopper (GLH). Resistance to GLH is common in rice germplasm but extremely rare for the two viruses. To induce mutations for tungro resistance, a susceptible variety IR22 was treated with N-methyl-N-nitrosourea (MNH) following the procedure of Satoh and Omura. The panicles of rice variety 'IR22' were soaked in 1 mM MNH solution for 45 minutes at 16 to 18 hours after flowering. Two thousand six hundred and forty fertile M 1 plants were produced. From these plants M 2 lines with 10 or more seedlings were planted in the field to evaluate their reaction against tungro under natural conditions in the 1990 dry season on the IRRI central research farm, Los Banos, the Philippines. Of these, 124 M 2 lines were selected by visual evaluation. Five plants were harvested individually from each selected line. A bulk was also made from all the remaining plants in the line. In the M 3 generation, each family consisted of five sister lines and one bulked line. One line (M 3 -723) showed no tungro symptoms and its related bulk segregated for resistance but all other M 3 lines from the same family were susceptible to tungro. The resistant line, M 3 -723, showed low infection with RTBV and RTSV when leaves were tested by enzyme-linked immunosorbent assay (ELISA) to diagnose tungro infection. All M 4 lines from M 3 -723 showed uniform resistance in the field. They were not infected with RTBV and were resistant to RTSV infection

  15. Performance of high amylose starch-composited gelatin films influenced by gelatinization and concentration.

    Science.gov (United States)

    Wang, Wenhang; Wang, Kun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana; Liu, Anjun

    2017-01-01

    In order to study the impact of starch in film performance, high amylose corn starch was composited in gelatin films under different gelatinization conditions and, in high and low concentrations (10 and 50wt.%). It was found that hot water gelatinized starch (Gel-Shw) increased film mechanical strength and was dependent upon the starch concentration. The addition of an alkali component to the starch significantly enhanced the swelling of the starch granules and expedited the gelatinization process. Incorporation of starch, especially the alkalized starch (Sha), into the gelatin films decreased film solubility which improved its water resistance and water vapor permeability (WVP). Multiple techniques (DSC, TGA, FT-IR, and XRD) were used to characterize the process and results, including the crosslinking of the dissolved starch molecules and the particles formed from gelatinized starch during retrogradation process, which played an important role in improving the thermal stability of the composited gelatin films. Overall, the starch-gelatin composition provides a potential approach to improve gelatin film performance and benefit its applications in the food industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

    Directory of Open Access Journals (Sweden)

    Yong-liang LU

    2014-09-01

    Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and

  17. Characteristics of bread prepared from wheat flours blended with various kinds of newly developed rice flours.

    Science.gov (United States)

    Nakamura, S; Suzuki, K; Ohtsubo, K

    2009-04-01

    Characteristics of the bread prepared from wheat flour blended with the flour of various kinds of newly developed rice cultivars were investigated. Qualities of the bread made from wheat flour blended with rice flour have been reported to be inferior to those from 100% wheat flour bread. To improve its qualities, we searched for the new-characteristic rice flours among the various kinds of newly developed rice cultivars to blend with the wheat flour for the bread preparation. The most suitable new characteristic rices are combination of purple waxy rice, high-amylose rice, and sugary rice. Specific volume of the bread from the combination of wheat and these 3 kinds of rice flours showed higher specific volume (3.93) compared with the traditional wheat/rice bread (3.58). We adopted the novel method, continuous progressive compression test, to measure the physical properties of the dough and the bread in addition to the sensory evaluation. As a result of the selection of the most suitable rice cultivars and blending ratio with the wheat flour, we could develop the novel wheat/rice bread, of which loaf volume, physical properties, and tastes are acceptable and resistant to firming on even 4 d after the bread preparation. To increase the ratio of rice to wheat, we tried to add a part of rice as cooked rice grains. The specific volume and qualities of the bread were maintained well although the rice content of total flour increased from 30% to 40%.

  18. Physical Characterization Of High Amylose/Pectin Mixtures Cross-Linked With Sodium Trimetaphosphate

    International Nuclear Information System (INIS)

    Carbinatto, F.M.; Cury, B.S.F.; Evangelista, R.C.

    2010-01-01

    Some researches have reported that pectin and high amylose mixtures presented superior mechanical properties in relation to those of the isolated polymers. In this work, mixtures at different ratios (1:4; 1:1) of pectin and high amylose were crosslinked with sodium trimetaphosphate at different degrees by varying reaction conditions. All samples were characterized by rheological and X-ray diffraction analyses. Samples without cross-linker were prepared as control. The oscillatory dynamic tests showed that all samples exhibited predominant elastic behavior, although cross-linked samples presented higher G' values, suggesting that crosslinking by phosphorylation resulted in more strength structures. The diffractograms showed that cross-linked samples underwent structural modifications that resulted in increase of crystallinity due to cross-linking process. (author)

  19. Laboratory Screening for Resistance in Rice to Rice Stem Borer Chilo Suppressalis Walker

    International Nuclear Information System (INIS)

    Singgih Sutrisno

    2004-01-01

    Rice stem borer Chilo suppressalis Walker is one of the major insect pests in rice in Indonesia. The use of insect pest resistant variety of rice is one of the effective techniques against pests. Breeding of resistance to insect pests rice crops often faced difficulties in obtaining a lot of insect amounts due to the unavailability of enough number insects pests in the field so that a laboratory bioassay is needed. In this experiments five rice varieties were used: a Pelita I/1, Atomita I, Cisadane, Cisanggarung, and IR 36. Rice seedling 7 days of age were put in 1 liter plastic vials for rice resistance test against the attack of insect pest C. suppressalis. The parameters observed were larval and pupal viability, pupal weight, and eggs production. The larval and pupal viability which were reared on of Pelita I/1 and Atomita I rice seedlings were 68.5 % - 55.5 % and 57.3 % - 46.7 % respectively. The respective lowest percentages were found in IR 36 which was about 41.3 % - 29.8 % .The experiment results on the parameters of pupal weight and egg production showed similar results to that on the parameters of larval and pupal viability. Rice variety of IR 36 showed more resistance to the other varieties, while Pelita I/1 and Atomita I showed the most susceptible to the attack of insect pest C. suppressalis. (author)

  20. Characterization and evaluation of rice blast resistance of Chinese indica hybrid rice parental lines

    Directory of Open Access Journals (Sweden)

    Yunyu Wu

    2017-12-01

    Full Text Available The development of resistant varieties and hybrid combinations has been the most effective and economical strategy to control blast disease caused by Magnaporthe oryzae. However, the distribution of major R genes and blast resistance characterization in hybrid rice parents has not been well investigated, resulting in their limited use in hybrid rice blast-resistance breeding. In the present study, 88 elite indica hybrid rice parental lines were evaluated with 30 isolates of M. oryzae collected from the main planting area of indica hybrid rice in China and were characterized for the presence of 11 major resistance genes using molecular markers. The pathogenicity assays showed that four types of hybrid rice parent line showed some resistance to M. oryzae. However, the proportions of highly resistant lines and the mean resistance frequency (RF varied among the four types, with resistance in decreasing order shown by three-line restorer lines, three-line maintainer lines, two-line sterile lines, and two-line restorer lines. All 88 hybrid rice parental lines carried more than one R gene, but none carried the R genes Pi1 and Pi2. Although Pid3 and Pi9 were present only in three-line restorer lines and Pigm only in three-line maintainer lines, the remaining six R genes (Pib, Pid2, Pi5, Pia, Pi54, and Pita were present in the four types of hybrid rice parent with significantly different distribution frequencies. The correlation between R genes and resistance reactions was investigated. The results are expected to provide useful information for rational utilization of major R genes in hybrid rice breeding programs. Keywords: Hybrid rice parental lines, Magnaporthe oryzae, Pi genes, Resistance evaluation, Molecular markers

  1. Induced lodging resistance in upland rice

    International Nuclear Information System (INIS)

    Arumugam Pillai, M.; Subramanian, M.

    1990-01-01

    Full text: Seeds of two short duration but tall upland rice varieties ''PMK 1'' and ''Poongar'', susceptible to lodging, were subjected to mutation breeding in 1988-1989. Dry seeds of these two varieties were treated with 20, 25 and 30 krad of gamma rays and soaked seeds were treated with 40, 50 and 60 mM concentration of EMS. In M 2 generation lodging was measured and a correlation study was made between the angle of lodging and various characters like plant height, length of lower internode, productive tiller number, culm diameter and panicle weight. The angle to which the main tiller can be bent before lodging on the 25th day after flowering was measured by using a protractor. Those plants which lodged at an angle beyond 30 deg. from the vertical plane were classified as lodging. From 60,000 M 2 plants, 78 lodging resistant semi-dwarf mutants and 5 dwarf mutants were selected. As expected, there was generally a negative correlation between internode length and lodging resistance and a positive correlation of culm diameter with lodging resistance. For plant height and tiller numbers, correlations were not so clear. (author)

  2. Breeding of ozone resistant rice: Relevance, approaches and challenges

    International Nuclear Information System (INIS)

    Frei, Michael

    2015-01-01

    Tropospheric ozone concentrations have been rising across Asia, and will continue to rise during the 21st century. Ozone affects rice yields through reductions in spikelet number, spikelet fertility, and grain size. Moreover, ozone leads to changes in rice grain and straw quality. Therefore the breeding of ozone tolerant rice varieties is warranted. The mapping of quantitative trait loci (QTL) using bi-parental populations identified several tolerance QTL mitigating symptom formation, grain yield losses, or the degradation of straw quality. A genome-wide association study (GWAS) demonstrated substantial natural genotypic variation in ozone tolerance in rice, and revealed that the genetic architecture of ozone tolerance in rice is dominated by multiple medium and small effect loci. Transgenic approaches targeting tolerance mechanisms such as antioxidant capacity are also discussed. It is concluded that the breeding of ozone tolerant rice can contribute substantially to the global food security, and is feasible using different breeding approaches. - Highlights: • Tropospheric ozone affects millions of hectares of rice land. • Ozone affects rice yield and quality. • Breeding approaches to adapt rice to high ozone are discussed. • Challenges in the breeding of ozone resistant rice are discussed. - This review summarizes the effects of tropospheric ozone on rice and outlines approaches and challenges in the breeding of adapted varieties

  3. Natural variation of rice blast resistance gene Pi-d2

    Science.gov (United States)

    Studying natural variation of rice resistance (R) genes in cultivated and wild rice relatives can predict resistance stability to rice blast fungus. In the present study, the protein coding regions of rice R gene Pi-d2 in 35 rice accessions of subgroups, aus (AUS), indica (IND), temperate japonica (...

  4. Increased Butyrate Production During Long-Term Fermentation of In Vitro-Digested High Amylose Cornstarch Residues with Human Feces.

    Science.gov (United States)

    Li, Li; Jiang, Hongxin; Kim, Hyun-Jung; Yum, Man-Yu; Campbell, Mark R; Jane, Jay-Lin; White, Pamela J; Hendrich, Suzanne

    2015-09-01

    An in vitro semi-continuous long-term (3 wk) anaerobic incubation system simulating lower gut fermentation was used to determine variability in gut microbial metabolism between 4 predigested high amylose-resistant starch residues (SR): SRV, SRVI, SRVII, and SRGEMS in human fecal samples. Subjects participated twice, 5 mo apart: 30 in Phase I (15 lean, 9 overweight and 6 obese), 29 in Phase II (15 lean, 9 overweight, 5 obese); 13 of 15 lean subjects participated in both phases. Of the 4 SRs, SRV displayed the highest gelatinization temperature, peak temperature, enthalpy changes, and the least digestibility compared with the other SRs. In both phases, compared with blank controls, all SRs increased butyrate ∼2-fold which stabilized at week 2 and only SRV caused greater propionate concentration (∼30%) after 3 wk which might have been partly mediated by its lesser digestibility. Fecal samples from lean and overweight/obese subjects incubated with SRs showed similar short-chain fatty acid production across both time points, which suggests that resistant starch may benefit individuals across BMIs. © 2015 Institute of Food Technologists®

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

    International Nuclear Information System (INIS)

    Nguyen Duc Thanh; Le Thi Bich Thuy; Dang Thi Minh Lua

    2008-01-01

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

  6. Formation of inclusion complexes between high amylose starch and octadecyl ferulate via steam jet cooking.

    Science.gov (United States)

    Kenar, James A; Compton, David L; Little, Jeanette A; Peterson, Steve C

    2016-04-20

    Amylose-ligand inclusion complexes represent an interesting approach to deliver bioactive molecules. However, ferulic acid has been shown not to form single helical inclusion complexes with amylose from high amylose maize starch. To overcome this problem a lipophilic ferulic acid ester, octadecyl ferulate, was prepared and complexed with amylose via excess steam jet cooking. Jet-cooking octadecyl ferulate and high amylose starch gave an amylose-octadecyl ferulate inclusion complex in 51.0% isolated yield. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed that a 61 V-type inclusion complex was formed. Amylose and extraction assays showed the complex to be enriched in amylose (91.9±4.3%) and contain 70.6±5.6mgg(-1) octadecyl ferulate, although, minor hydrolysis (∼4%) of the octadecyl ferulate was observed under the excess steam jet-cooking conditions utilized. This study demonstrates that steam jet cooking is a rapid and scalable process in which to prepare amylose-octadecyl ferulate inclusion complexes. Published by Elsevier Ltd.

  7. Major QTL Conferring Resistance to Rice Bacterial Leaf Streak

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropical and sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene was located in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS was identified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregation populations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markers RM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DI populations, respectively. The genetic pattern of rice resistance to BLS was discussed.

  8. Identification of Striga hermonthica-Resistant Upland Rice Varieties in Sudan and Their Resistance Phenotypes

    OpenAIRE

    Samejima, Hiroaki; Babiker, Abdel G.; Mustafa, Ahmed; Sugimoto, Yukihiro

    2016-01-01

    Rice has become a major staple cereal in sub-Saharan Africa. Currently, upland rice cultivation is expanding particularly in rainfed areas where the root parasitic weed Striga hermonthica, a major constraint to cereal production, is endemic. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. In the laboratory, 27 varieties were screened for post-attachment resistance using...

  9. Defensive Responses of Rice Genotypes for Resistance Against Rice Leaffolder Cnaphalocrocis medinalis

    Directory of Open Access Journals (Sweden)

    M. PUNITHAVALLI

    2013-09-01

    Full Text Available The experiment was carried out to assess the reaction of different categories of rice genotypes viz., resistant, susceptible, hybrid, scented, popular and wild in response to the infestation by rice leaffolder (RLF, Cnaphalocrocis medinalis (Guenee and to explore the possible use of these genotypes in developing RLF-resistant rice varieties. The changes of various biochemical constituents such as leaf soluble protein, phenol, ortho-dihydroxy phenol, tannin and enzymes viz., peroxidase, phenyl alanine ammonia lyase (PAL were assessed spectrophotometrically in all the rice genotypes before and after RLF infestation. The protein profile was analyzed using sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE method. A significant constituent of biochemical content such as tannin, phenol and ortho-dihydroxy phenol has been increased along with enzyme activities of peroxidase and PAL in the infested resistant (Ptb 33, TKM6 and LFR831311 and wild rice genotypes (Oryza minuta and O. rhizomatis. A decrease in leaf protein content was evident invariably in all the infested rice genotypes. It is also evident that the contents of biochemicals such as phenol, ortho-dihydroxy phenol and tannin were negatively correlated with leaffolder damage. However, leaf protein content was positively correlated with the damage by rice leaffolder. SDS-PAGE analysis for total protein profiling of healthy and C. medinalis-infested genotypes revealed the enhanced expression of a high molecular weight (> 97 kDa protein in all the genotypes. Besides, there was also an increased induction of a 38 kDa protein in C. medinalis infested resistant genotypes, which was absent in uninfested plants. The present investigation proved that the elevated levels of biochemicals and enzymes may play a vital role in rice plants resistance to RLF.

  10. Small brown planthopper resistance loci in wild rice (Oryza officinalis).

    Science.gov (United States)

    Zhang, Weilin; Dong, Yan; Yang, Ling; Ma, Bojun; Ma, Rongrong; Huang, Fudeng; Wang, Changchun; Hu, Haitao; Li, Chunshou; Yan, Chengqi; Chen, Jianping

    2014-06-01

    Host-plant resistance is the most practical and economical approach to control the rice planthoppers. However, up to date, few rice germplasm accessions that are resistant to the all three kinds of planthoppers (1) brown planthopper (BPH; Nilaparvata lugens Stål), (2) the small brown planthopper (SBPH; Laodelphax striatellus Fallen), and (3) the whitebacked planthopper (WBPH, Sogatella furcifera Horvath) have been identified; consequently, the genetic basis for host-plant broad spectrum resistance to rice planthoppers in a single variety has been seldom studied. Here, one wild species, Oryza officinalis (Acc. HY018, 2n = 24, CC), was detected showing resistance to the all three kinds of planthoppers. Because resistance to WBPH and BPH in O. officinalis has previously been reported, the study mainly focused on its SBPH resistance. The SBPH resistance gene(s) was (were) introduced into cultivated rice via asymmetric somatic hybridization. Three QTLs for SBPH resistance detected by the SSST method were mapped and confirmed on chromosomes 3, 7, and 12, respectively. The allelic/non-allelic relationship and relative map positions of the three kinds of planthopper resistance genes in O. officinalis show that the SBPH, WBPH, and BPH resistance genes in O. officinalis were governed by multiple genes, but not by any major gene. The data on the genetics of host-plant broad spectrum resistance to planthoppers in a single accession suggested that the most ideally practical and economical approach for rice breeders is to screen the sources of broad spectrum resistance to planthoppers, but not to employ broad spectrum resistance gene for the management of planthoppers. Pyramiding these genes in a variety can be an effective way for the management of planthoppers.

  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. Genetic analysis of rice blast disease resistance genes using USDA rice mini-core and a mapping population

    Science.gov (United States)

    Rice blast disease caused by the fungal pathogen Magnaporthe oryzae (M. oryzae) is one of the most destructive diseases of cultivated rice, resulting in significant yield loss each year all over the world. Developing and utilizing blast resistant rice varieties is the most economical and effective m...

  13. The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice.

    Science.gov (United States)

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D; Huang, Zhongyun; Hyma, Katie E; Gealy, David R; Caicedo, Ana L

    2014-11-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. © 2014 American Society of Plant Biologists. All Rights Reserved.

  14. Survey of rice blast race identity for blast resistance gene identification in the USA and Puerto Rico

    Science.gov (United States)

    Rice blast disease is a significant threat to stable rice production in the USA and worldwide. The major resistance gene (Pi-ta) located within a cluster of resistance genes on rice chromosome 12 has been demonstrated to confer resistance to the rice blast disease. Katy, a rice cultivar released in ...

  15. Identification of blast resistance expression in rice genotypes using ...

    African Journals Online (AJOL)

    Rice is the second most important cereal crop of developing countries and the staple food of about 65% of the world's population. In this endeavor, it is important to identify resistant gene(s) with the help of markers. Once a gene is tagged with a molecular marker, it can be transferred selectively into different genetic ...

  16. Genetic analysis of Resistance to Rice Bacterial blight in Uganda ...

    African Journals Online (AJOL)

    A full-diallel mating design involving three resistant and three susceptible rice cultivars was used to produce F1 and F2 progenies in a screen-house at the National Crop Resources Research Institute (NaCRRI), Namulonge in Uganda. The parents and F2 populations were challenged with the Xanthomonas oryzae ...

  17. Mechanisms of UVB-resistance in rice: Cultivar differences in the sensitivity to UVB radiation in rice

    International Nuclear Information System (INIS)

    Hidema, J.

    2001-01-01

    In a study on the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, results showed that the rice cultivars widely varied in UVB sensitivity; among the Japanese rice cultivars, Sasanishiki was more resistant to UVB, while Norin 1 was less resistant; UV-sensitive Norin 1 was deficient in photorepair of cyclobutane pyrimidine dimers (UV-induced DNA damage), and the sensitivity to UVB radiation significantly correlated with deficient CPD photorepair; and that this deficiency in Norin 1 resulted from a functionally altered photolyase. The results suggest that photorepair capacity is a principal factor in determining UVB sensitivity in rice. The effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars under field conditions were also studied in Japan since 1993. The results indicate that supplemental UVB radiation had inhibitory effects on the growth and yield of rice. Furthermore, grain size was smaller with supplemental UVB radiation

  18. Genetic mapping of the rice resistance-breaking gene of the brown planthopper Nilaparvata lugens

    OpenAIRE

    Kobayashi, Tetsuya; Yamamoto, Kimiko; Suetsugu, Yoshitaka; Kuwazaki, Seigo; Hattori, Makoto; Jairin, Jirapong; Sanada-Morimura, Sachiyo; Matsumura, Masaya

    2014-01-01

    Host plant resistance has been widely used for controlling the major rice pest brown planthopper (BPH, Nilaparvata lugens). However, adaptation of the wild BPH population to resistance limits the effective use of resistant rice varieties. Quantitative trait locus (QTL) analysis was conducted to identify resistance-breaking genes against the anti-feeding mechanism mediated by the rice resistance gene Bph1. QTL analysis in iso-female BPH lines with single-nucleotide polymorphism (SNP) markers d...

  19. Effect of amylose:amylopectin ratio and rice bran addition on starch films properties.

    Science.gov (United States)

    Cano, Amalia; Jiménez, Alberto; Cháfer, Maite; Gónzalez, Chelo; Chiralt, Amparo

    2014-10-13

    The influence of the amylose:amylopectin ratio on the properties of pea, potato and cassava starch films and the effect of the incorporation of rice bran of two different particle sizes were studied. The structural, mechanical, optical and barrier properties of the films were analyzed after 1 and 5 weeks. The high content of amylose gave rise to stiffer, more resistant to fracture, but less stretchable films, with lower oxygen permeability and greater water binding capacity. Although no changes in the water vapour permeability values of the films were observed during storage, their oxygen permeability decreased. Throughout storage, films became stiffer, more resistant to break, but less stretchable. Rice bran with the smallest particles improved the elastic modulus of the films, especially in high amylose content films, but reduced the film stretchability and its barrier properties, due to the enhancement of the water binding capacity and the introduction of discontinuities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Rheological Properties and Electrospinnability of High-Amylose Starch in Formic Acid.

    Science.gov (United States)

    Lancuški, Anica; Vasilyev, Gleb; Putaux, Jean-Luc; Zussman, Eyal

    2015-08-10

    Starch derivatives, such as starch-esters, are commonly used as alternatives to pure starch due to their enhanced mechanical properties. However, simple and efficient processing routes are still being sought out. In the present article, we report on a straightforward method for electrospinning high-amylose starch-formate nanofibers from 17 wt % aqueous formic acid (FA) dispersions. The diameter of the electrospun starch-formate fibers ranged from 80 to 300 nm. The electrospinnability window between starch gelatinization and phase separation was determined using optical microscopy and rheological studies. This window was shown to strongly depend on the water content in the FA dispersions. While pure FA rapidly gelatinized starch, yielding solutions suitable for electrospinning within a few hours at room temperature, the presence of water (80 and 90 vol % FA) significantly delayed gelatinization and dissolution, which deteriorated fiber quality. A complete destabilization of the electrospinning process was observed in 70 vol % FA dispersions. Optical micrographs showed that FA induced a disruption of starch granule with a loss of crystallinity confirmed by X-ray diffraction. As a result, starch fiber mats exhibited a higher elongation at break when compared to brittle starch films.

  1. RNAi-mediated resistance to rice black-streaked dwarf virus in transgenic rice.

    Science.gov (United States)

    Ahmed, Mohamed M S; Bian, Shiquan; Wang, Muyue; Zhao, Jing; Zhang, Bingwei; Liu, Qiaoquan; Zhang, Changquan; Tang, Shuzhu; Gu, Minghong; Yu, Hengxiu

    2017-04-01

    Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Development of resistant varieties by using conventional breeding methods is limited, as germplasm with high level of resistance to RBSDV have not yet been found. One of the most promising methods to confer resistance against RBSDV is the use of RNA interference (RNAi) technology. RBSDV non-structural protein P7-2, encoded by S7-2 gene, is a potential F-box protein and involved in the plant-virus interaction through the ubiquitination pathway. P8, encoded by S8 gene, is the minor core protein that possesses potent active transcriptional repression activity. In this study, we transformed rice calli using a mini-twin T-DNA vector harboring RNAi constructs of the RBSDV genes S7-2 or S8, and obtained plants harboring the target gene constructs and the selectable marker gene, hygromycin phosphotransferase (HPT). From the offspring of these transgenic plants, we obtained selectable marker (HPT gene)-free plants. Homozygous T 5 transgenic lines which harbored either S7-2-RNAi or S8-RNAi exhibited high level resistance against RBSDV under field infection pressure from indigenous viruliferous small brown planthoppers. Thus, our results showed that RNA interference with the expression of S7-2 or S8 genes seemed an effective way to induce high level resistance in rice against RBSD disease.

  2. Molecular evolution of the rice blast resistance gene Pi-ta in invasive weedy rice in the USA.

    Directory of Open Access Journals (Sweden)

    Seonghee Lee

    Full Text Available The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus, which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH, suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta, not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing.

  3. Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

    Science.gov (United States)

    Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

    2011-01-01

    The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312

  4. In vitro utilization of amylopectin and high-amylose maize (Amylomaize) starch granules by human colonic bacteria.

    Science.gov (United States)

    Wang, X; Conway, P L; Brown, I L; Evans, A J

    1999-11-01

    It has been well established that a certain amount of ingested starch can escape digestion in the human small intestine and consequently enters the large intestine, where it may serve as a carbon source for bacterial fermentation. Thirty-eight types of human colonic bacteria were screened for their capacity to utilize soluble starch, gelatinized amylopectin maize starch, and high-amylose maize starch granules by measuring the clear zones on starch agar plates. The six cultures which produced clear zones on amylopectin maize starch- containing plates were selected for further studies for utilization of amylopectin maize starch and high-amylose maize starch granules A (amylose; Sigma) and B (Culture Pro 958N). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to detect bacterial starch-degrading enzymes. It was demonstrated that Bifidobacterium spp., Bacteroides spp., Fusobacterium spp., and strains of Eubacterium, Clostridium, Streptococcus, and Propionibacterium could hydrolyze the gelatinized amylopectin maize starch, while only Bifidobacterium spp. and Clostridium butyricum could efficiently utilize high-amylose maize starch granules. In fact, C. butyricum and Bifidobacterium spp. had higher specific growth rates in the autoclaved medium containing high-amylose maize starch granules and hydrolyzed 80 and 40% of the amylose, respectively. Starch-degrading enzymes were cell bound on Bifidobacterium and Bacteroides cells and were extracellular for C. butyricum. Active staining for starch-degrading enzymes on SDS-PAGE gels showed that the Bifidobacterium cells produced several starch-degrading enzymes with high relative molecular (M(r)) weights (>160,000), medium-sized relative molecular weights (>66,000), and low relative molecular weights (spp. and C. butyricum degraded and utilized granules of amylomaize starch.

  5. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease

    Science.gov (United States)

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammoni...

  6. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease (CKD)

    Science.gov (United States)

    Patients with advanced CKD exhibit profound changes in the composition and function of the gut microbiome. This is, in part, mediated by: I- heavy influx of urea in the intestinal tract leading to the dominance of urease-possessing bacteria and II- dietary restriction of potassium-rich fruits and ve...

  7. Studies on induced resistance to blast in rice

    International Nuclear Information System (INIS)

    Zhang Mingxian

    1985-01-01

    Eleven rice varieties were treated with 60 Co gamma ray, laser and other mutagens. 154 mutants with different characters were developed. 154 mutants and their parents have been inoculated with blast (Piricularia oryzae) races. It was found that the mutants of disease-resistance could be produced. The disease-resistant mutants with various better cheracters were selected. The frequencies of mutation in disease-resistance are different with different parental varieties. After inoculation with 13 blast physiological races, the results showed that the spectrum of resistance of mutants, other characters were changed, when one character was changed. In order to get a veriety with higher yield and disease-resistance, it is important to take account of other economic charaters

  8. Transgenic strategies for improving rice disease resistance

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... practice. However, the useful life-span of many resistant cultivars is only a few years, due to the breakdown of the .... Thus, suppression of insect feeding by transgenic .... different types of defense-responsive genes were found.

  9. Transgenic rice plants expressing synthetic cry2AX1 gene exhibits resistance to rice leaffolder (Cnaphalocrosis medinalis).

    Science.gov (United States)

    Manikandan, R; Balakrishnan, N; Sudhakar, D; Udayasuriyan, V

    2016-06-01

    Bacillus thuringiensis is a major source of insecticidal genes imparting insect resistance in transgenic plants. Level of expression of transgenes in transgenic plants is important to achieve desirable level of resistance against target insects. In order to achieve desirable level of expression, rice chloroplast transit peptide sequence was fused with synthetic cry2AX1 gene to target its protein in chloroplasts. Sixteen PCR positive lines of rice were generated by Agrobacterium mediated transformation using immature embryos. Southern blot hybridization analysis of T 0 transgenic plants confirmed the integration of cry2AX1 gene in two to five locations of rice genome and ELISA demonstrated its expression. Concentration of Cry2AX1 in transgenic rice events ranged 5.0-120 ng/g of fresh leaf tissue. Insect bioassay of T 0 transgenic rice plants against neonate larvae of rice leaffolder showed larval mortality ranging between 20 and 80 % in comparison to control plant. Stable inheritance and expression of cry2AX1 gene was demonstrated in T 1 progenies through Southern and ELISA. In T 1 progenies, the highest concentration of Cry2AX1 and mortality of rice leaffolder larvae were recorded as 150 ng/g of fresh leaf tissue and 80 %, respectively. The Cry2AX1 expression even at a very low concentration (120-150 ng/g) in transgenic rice plants was found effective against rice leaffolder larvae.

  10. Drought resistant rice mutants, characteristics and discussions on possibilities for planting them in some Arab Countries which import rice

    International Nuclear Information System (INIS)

    Abo-Hegazi, A.M.T.

    1994-01-01

    A number of drought resistant mutants of rice were produced from ordinary rice varieties being planted in several parts of Egypt through utilization of gamma rays as a mutagen. The mutants have water requirements less than one half of that of their mother varieties. According to official data, authorities in Egypt insure about 18000 M 3 of irrigation water for every hectare (10000 M 2 ) of rice and about 6700 M 3 , 6900 M 3 for every hectare of corn and ground nuts, respectively. Peanuts and corn are summer crops like the drought resistant rice mutants. The mentioned mutants can produce good yield under water requirements very near to that of corn and peanuts. The wide gap in agricultural food stuffs for the Arab Countries (more than 20000 million US $ annually) includes rice imports usually exceeds 700 million US $ per year> Rice imports of Arab Countries such as Saudi Arabia, Yemen, Syria, Libya and the Sudan, reached 180, 47, 21, 16 and 14 million US $ in 1988 as an example. Such countries could make use of the drought resistant rice mutants for plantation on water requirements very near to those of usual summer crops such as corn and peanuts which is significantly less than one half of water requirements of their mother varieties. Some characteristics of such mutants as well as discussions on possibilities for planting them in some of the nominated Arab Countries are presented. However, arrangements for ensuring the minimum water requirements during the growing period irrespective to rain which in many cases did not accord the growing period of the mutants should be taken if such countries wants to make use of the drought resistant rice mutants. The author believe that most if not all requirements of rice of such countries could locally be ensured through planting of the above mentioned rice mutants. In this case, maximizing the efficiency of utilizing the limited water resources of such countries could also be counted as another cause for presenting this

  11. Identification of lead-resistant endophytic bacteria isolated from rice

    International Nuclear Information System (INIS)

    Perez-Cordero, Alexander; Barraza-Roman, Zafiro; Martinez-Pacheco, Dalila

    2015-01-01

    Resistance of endophytic bacteria in vitro was evaluated at different lead concentrations. The tissue samples of commercial rice varieties at tillering stage were collected during the first half of 2013, in Monteria, Cordoba, Colombia. Each tissue was subjected to surface cleaning. Endophytic bacteria were isolated in agar R_2A medium. The population density (CFU/g tissue) was determined from each tissue by direct counting of R_2A medium surface. Morphotypes were classified by shape, color, size and appearance. A total of 168 morphotypes were isolated from root, tillers and leaf of different commercial varieties of rice. The lead resistance test is performed in vitro, The lead resistance test was performed in vitro, by the suspensions of endophytic bacteria in log phase and inoculation in minimal medium with five concentrations of lead as Pb (NO_3)_2. The experiment was incubated at 32 degrees celsius and agitated at 150 rpm for five days. The measure of turbidimetry at 600 nm was conduced every hour afterstarting the test. Endophytic bacteria showed the ability to grow at concentrations of 100% of Pb as Pb (NO_3) _2. The presence of Burkholderia cepacia and Pseudomonas putida, which showed resistance to differents lead concentration was confirmed as result of the identification with kit API20E. (author) [es

  12. Geographic and Research Center Origins of Rice Resistance to Asian Planthoppers and Leafhoppers: Implications for Rice Breeding and Gene Deployment

    Directory of Open Access Journals (Sweden)

    Finbarr G. Horgan

    2017-09-01

    Full Text Available This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs indicated a clade of highly resistant varieties from South Asia with two further South Asian clades of moderate resistance. Greenhouse bioassays indicated that planthoppers can develop virulence against multiple resistance genes including genes introgressed from wild rice species. Nilaparvata lugens populations from Punjab (India and the Mekong Delta (Vietnam were highly virulent to a range of key resistance donors irrespective of variety origin. Sogatella furcifera populations were less virulent to donors than N. lugens; however, several genes for resistance to S. furcifera are now ineffective in East Asia. A clade of International Rice Research Institute (IRRI-bred varieties and breeding lines, without identified leafhopper-resistance genes, were highly resistant to the green leafhopper, Nephotettix virescens. Routine phenotyping during breeding programs likely maintains high levels of quantitative resistance to leafhoppers. We discuss these results in the light of breeding and deploying resistant rice in Asia.

  13. Identification of lead- resistant endophytic bacteria isolated from rice.

    Directory of Open Access Journals (Sweden)

    Alexander Pérez-Cordero

    2015-06-01

    Full Text Available   The objective of this study was to evaluate in vitro the endophytic bacteria resistance to different lead concentrations. The sampling was undertaken in the first half of 2013, when tissue samples of commercial varieties of rice at tillering stage were collected in Montería, Cordoba, Colombia. Each tissue was subjected to surface cleaning. Endophytic bacteria in agar R2A medium were isolated. Population density (CFU/g tissue was determined from each tissue, by direct counting of R2A medium surface. morphotypes were classified by shape, color, size, and appearance. A total of 168 morphotypes were isolated from root, tillers, and leaf of different commercial varieties of rice. The lead resistance test was performed in vitro, to do that, suspensions of endophytic bacteria in log phase were prepared and inoculated in minimal medium with five concentrations of lead as Pb(NO32. The experiment was incubated at 32 °C and agitated at 150 rpm, for five days. Every hour afterstarting the test, turbidimetry measuring at 600 nm was conducted. Results showed the ability of endophytic bacteria to grow at concentrations of 100% of Pb as Pb(NO32. The results of the identification with kit API20E confirmed the presence of Burkholderia cepacia and Pseudomonas putida, which showed resistance to different lead concentrations.

  14. Resistance of rice to insect pests mediated by suppression of serotonin biosynthesis.

    Science.gov (United States)

    Lu, Hai-Ping; Luo, Ting; Fu, Hao-Wei; Wang, Long; Tan, Yuan-Yuan; Huang, Jian-Zhong; Wang, Qing; Ye, Gong-Yin; Gatehouse, Angharad M R; Lou, Yong-Gen; Shu, Qing-Yao

    2018-05-07

    Rice is one of the world's most important foods, but its production suffers from insect pests, causing losses of billions of dollars, and extensive use of environmentally damaging pesticides for their control 1,2 . However, the molecular mechanisms of insect resistance remain elusive. Although a few resistance genes for planthopper have been cloned, no rice germplasm is resistant to stem borers. Here, we report that biosynthesis of serotonin, a neurotransmitter in mammals 3 , is induced by insect infestation in rice, and its suppression confers resistance to planthoppers and stem borers, the two most destructive pests of rice 2 . Serotonin and salicylic acid derive from chorismate 4 . In rice, the cytochrome P450 gene CYP71A1 encodes tryptamine 5-hydroxylase, which catalyses conversion of tryptamine to serotonin 5 . In susceptible wild-type rice, planthopper feeding induces biosynthesis of serotonin and salicylic acid, whereas in mutants with an inactivated CYP71A1 gene, no serotonin is produced, salicylic acid levels are higher and plants are more insect resistant. The addition of serotonin to the resistant rice mutant and other brown planthopper-resistant genotypes results in a loss of insect resistance. Similarly, serotonin supplementation in artificial diet enhances the performance of both insects. These insights demonstrate that regulation of serotonin biosynthesis plays an important role in defence, and may prove valuable for breeding insect-resistant cultivars of rice and other cereal crops.

  15. Resistance of Rice Varieties to the Stored-Product Insect, Sitophilus zeamais (Coleoptera: Curculionidae).

    Science.gov (United States)

    Antunes, Catarina; Mendes, Raquel; Lima, Arlindo; Barros, Graça; Fields, Paul; Da Costa, Luísa Beirão; Rodrigues, José Carlos; Silva, Maria José; Correia, Augusto Manuel; Carvalho, Maria Otilia

    2016-02-01

    Four common Portuguese rice varieties--Thaibonnet, Gladio, Albatros, and Eurosis--were tested for their relative susceptibility to Sitophilus zeamais Motschulsky, a common pest of stored rice in Portugal and in tropical countries. Physical (moisture content, hardness, length, and width) and chemical (by attenuated total reflection-Fourier transform infrared spectroscopy) properties of rice kernels were measured. Insect bioassays measured median developmental time, Dobie's index of susceptibility, percentage of damaged grains and weight loss, and progeny developed. This was done for paddy, brown rice, and polished rice for each variety. There were small, but significant, differences in insect resistance among the varieties. However, it was different for paddy and polished rice. In paddy, these differences were correlated with hull damage, and Eurosis was the most susceptible variety. In polished rice, resistance was correlated with hardness, and Thaibonnet was the most susceptible variety. In general, paddy rice was more resistant to insect attack, followed by polished rice and then brown rice. Paddy kernels selected with undamaged hull were completely resistant to attack. Implications for IPM and breeding for resistant varieties are discussed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Comparative study on resistant starch, amilose content and glycaemic index after precooked process in white rice

    Science.gov (United States)

    Pratiwi, V. N.

    2018-03-01

    Rice is a staple food and regarded as a useful carbohydrate source. In general rice is high in glycaemic index (GI) and low colonic fermentation. People are aware of the alterations in blood glucose levels or glycaemic index after consuming rice. Resistant starch (RS) and amylose content play an important role in controlling GI. GI and RS content have been established as important indicators of starch digestibility. The aim of this study was to determine the precooked process with hydrothermal (boiling at 80°C, 10 minutes) and cooling process with low temperature (4°C, 1 h) to increase potential content of RS and decrease of glycaemic index of white rice. There were two stages of this research, 1) preparation of white rice with precooked process; 2) analysis of precooked white rice characteristics (resistant starch, amylose content, and estimated glycaemic index). The result of analysis on precooked white rice showed an increased RS content (1.11%) and white rice (0.99%), but the difference was not statistically significant. The amylose content increased significantly after precooked process in white rice (24.70%) compared with white rice (20.89%). Estimated glycaemic index (EGI) decreased after precooked proses (65.63%) but not significant as compared to white rice (66.47%). From the present study it was concluded that precooked process had no significant impact on increasing RS and decreasing EGI of white rice. This may be due to the relatively short cooling time (1hour) in 4°C.

  17. 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.

  18. Symbiont-mediated adaptation by planthoppers and leafhoppers to resistant rice varieties

    NARCIS (Netherlands)

    Ferrater, J.B.; Jong, de P.W.; Dicke, M.; Chen, Y.H.; Horgan, F.G.

    2013-01-01

    For over 50 years, host plant resistance has been the principal focus of public research to reduce planthopper and leafhopper damage to rice in Asia. Several resistance genes have been identified from native varieties and wild rice species, and some of these have been incorporated into high-yielding

  19. Geographic and research center origins of rice resistance to asian planthoppers and leafhoppers: implications for rice breeding and gene deployment

    NARCIS (Netherlands)

    Horgan, F.G.; Srinivasan, Thanga Suja; Bentur, Jagadish S.; Kumar, R.; Bhanu, K.V.; Singh Sarao, Preetinder; Chien, Ho Van; Almazan, M.L.P.; Bernal, Carmencita C.; Ramal, Angelee Fame; Ferrater, J.B.; Huang, Shou Horng

    2017-01-01

    This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia.

  20. Insights into the swelling process and drug release mechanisms from cross-linked pectin/high amylose starch matrices

    Directory of Open Access Journals (Sweden)

    Fernanda M. Carbinatto

    2014-02-01

    Full Text Available Cross-linked pectin/high amylose mixtures were evaluated as a new excipient for matrix tablets formulations, since the mixing of polymers and cross-linking reaction represent rational tools to reach materials with modulated and specific properties that meet specific therapeutic needs. Objective: In this work the influence of polymer ratio and cross-linking process on the swelling and the mechanism driving the drug release from swellable matrix tablets prepared with this excipient was investigated. Methods: Cross-linked samples were characterized by their micromeritic properties (size and shape, density, angle of repose and flow rate and liquid uptake ability. Matrix tablets were evaluated according their physical properties and the drug release rates and mechanisms were also investigated. Results: Cross-linked samples demonstrated size homogeneity and irregular shape, with liquid uptake ability insensible to pH. Cross-linking process of samples allowed the control of drug release rates and the drug release mechanism was influenced by both polymer ratio and cross-linking process. The drug release of samples with minor proportion of pectin was driven by an anomalous transport and the increase of the pectin proportion contributed to the erosion of the matrix. Conclusion: The cross-linked mixtures of high amylose and pectin showed a suitable excipient for slowing the drug release rates.

  1. High-amylose sodium carboxymethyl starch matrices: development and characterization of tramadol hydrochloride sustained-release tablets for oral administration.

    Science.gov (United States)

    Nabais, Teresa; Leclair, Grégoire

    2014-01-01

    Substituted amylose (SA) polymers were produced from high-amylose corn starch by etherification of its hydroxyl groups with chloroacetate. Amorphous high-amylose sodium carboxymethyl starch (HASCA), the resulting SA polymer, was spray-dried to obtain an excipient (SD HASCA) with optimal binding and sustained-release (SR) properties. Tablets containing different percentages of SD HASCA and tramadol hydrochloride were produced by direct compression and evaluated for dissolution. Once-daily and twice-daily SD HASCA tablets containing two common dosages of tramadol hydrochloride (100 mg and 200 mg), a freely water-soluble drug, were successfully developed. These SR formulations presented high crushing forces, which facilitate further tablet processing and handling. When exposed to both a pH gradient simulating the pH variations through the gastrointestinal tract and a 40% ethanol medium, a very rigid gel formed progressively at the surface of the tablets providing controlled drug-release properties. These properties indicated that SD HASCA was a promising and robust excipient for oral, sustained drug-release, which may possibly minimize the likelihood of dose dumping and consequent adverse effects, even in the case of coadministration with alcohol.

  2. Identification of Striga hermonthica-resistant Upland Rice Varieties in Sudan and Their Resistance Phenotypes

    Directory of Open Access Journals (Sweden)

    Hiroaki eSamejima

    2016-05-01

    Full Text Available Rice has become a major staple cereal in sub-Saharan Africa. Currently, upland rice cultivation is expanding particularly in rainfed areas where the root parasitic weed Striga hermonthica, a major constraint to cereal production, is endemic. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. In the laboratory, 27 varieties were screened for post-attachment resistance using the rhizotron technique. Varieties displaying high post-attachment resistance, Umgar, NERICA5, and NERICA13 together with NERICA4, NERICA18, and Nipponbare, a lowland rice variety, were further evaluated for performance and Striga resistance in pot and semi-controlled open air experiments and for germination inducing activity in a laboratory. In addition, comparative studies on reaction of Umgar, Kosti1 and Kosti2, released varieties for commercial production in Sudan, to the parasite were performed in two pot experiments. In the pot experiments Umgar and NERICA5, consistently, sustained the lowest Striga emergence (< 2.2 Striga plants per pot, while NERICA13 and NERICA4 supported 1.8–5.7 and 8.7–16.4 Striga plants per pot, respectively. In an artificially Striga-infested field, number of emergent Striga plants per 10 rice hills, at harvest, was 2.0, 2.0, 4.8, 13.5, 13.3, and 18.3 on Umgar, NERICA5, NERICA13, NERICA4, NERICA18, and Nipponbare, respectively. Striga had no adverse effects on total above-ground parts and panicle dry weight (DW in Umgar and NERICA5. Germination-inducing activity of root exudates, at 14 days after sowing onwards, was markedly lower for Umgar than for NERICA5, NERICA13, NERICA4, and NERICA18. Based on these findings, Umgar has both pre and post-attachment resistance to a resident Striga population in Sudan. Kosti1 and Kosti2, did not exhibit Striga-resistance at the same level as Umgar. Further the resistance of NERICA5, a

  3. Identification of Striga hermonthica-Resistant Upland Rice Varieties in Sudan and Their Resistance Phenotypes.

    Science.gov (United States)

    Samejima, Hiroaki; Babiker, Abdel G; Mustafa, Ahmed; Sugimoto, Yukihiro

    2016-01-01

    Rice has become a major staple cereal in sub-Saharan Africa. Currently, upland rice cultivation is expanding particularly in rainfed areas where the root parasitic weed Striga hermonthica, a major constraint to cereal production, is endemic. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. In the laboratory, 27 varieties were screened for post-attachment resistance using the rhizotron technique. Varieties displaying high post-attachment resistance, Umgar, NERICA5, and NERICA13 together with NERICA4, NERICA18, and Nipponbare, a lowland rice variety, were further evaluated for performance and Striga resistance in pot and semi-controlled open air experiments and for germination inducing activity in a laboratory. In addition, comparative studies on reaction of Umgar, Kosti1 and Kosti2, released varieties for commercial production in Sudan, to the parasite were performed in two pot experiments. In the pot experiments Umgar and NERICA5, consistently, sustained the lowest Striga emergence (pot), while NERICA13 and NERICA4 supported 1.8-5.7 and 8.7-16.4 Striga plants per pot, respectively. In an artificially Striga-infested field, number of emergent Striga plants per 10 rice hills, at harvest, was 2.0, 2.0, 4.8, 13.5, 13.3, and 18.3 on Umgar, NERICA5, NERICA13, NERICA4, NERICA18, and Nipponbare, respectively. Striga had no adverse effects on total above-ground parts and panicle dry weight in Umgar and NERICA5. Germination-inducing activity of root exudates, at 14 days after sowing onward, was markedly lower for Umgar than for NERICA5, NERICA13, NERICA4, and NERICA18. Based on these findings, Umgar has both pre and post-attachment resistance to a resident Striga population in Sudan. Kosti1 and Kosti2 did not exhibit Striga-resistance at the same level as Umgar. Further the resistance of NERICA5, a variety reported to be endowed with a broad spectrum

  4. The Impact of Herbicide-Resistant Rice Technology on Phenotypic Diversity and Population Structure of United States Weedy Rice1[W][OPEN

    Science.gov (United States)

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D.; Huang, Zhongyun; Hyma, Katie E.; Gealy, David R.; Caicedo, Ana L.

    2014-01-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

  5. Molecular Scree ning of Blast Resistance Genes in Rice Germplasms Resistant to Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Liang Yan

    2017-01-01

    Full Text Available Molecular screening of major rice blast resistance genes was determined with molecular markers, which showed close-set linkage to 11 major rice blast resistance genes (Pi-d2, Pi-z, Piz-t, Pi-9, Pi-36, Pi-37, Pi5, Pi-b, Pik-p, Pik-h and Pi-ta2, in a collection of 32 accessions resistant to Magnaporthe oryzae. Out of the 32 accessions, the Pi-d2 and Pi-z appeared to be omnipresent and gave positive express. As the second dominant, Pi-b and Piz-t gene frequencies were 96.9% and 87.5%. And Pik-h and Pik-p gene frequencies were 43.8% and 28.1%, respectively. The molecular marker linkage to Pi-ta2 produced positive bands in eleven accessions, while the molecular marker linkage to Pi-36 and Pi-37 in only three and four accessions, respectively. The natural field evaluation analysis showed that 30 of the 32 accessions were resistant, one was moderately resistant and one was susceptible. Infection types were negatively correlated with the genotype scores of Pi-9, Pi5, Pi-b, Pi-ta2 and Pik-p, although the correlation coefficients were very little. These results are useful in identification and incorporation of functional resistance genes from these germplasms into elite cultivars through marker-assisted selection for improved blast resistance in China and worldwide.

  6. Transgenic rice plants harboring an introduced potato proteinase inhibitor II gene are insect resistant.

    Science.gov (United States)

    Duan, X; Li, X; Xue, Q; Abo-el-Saad, M; Xu, D; Wu, R

    1996-04-01

    We introduced the potato proteinase inhibitor II (PINII) gene (pin2) into several Japonica rice varieties, and regenerated a large number of transgenic rice plants. Wound-inducible expression of the pin2 gene driven by its own promoter, together with the first intron of the rice actin 1 gene (act1), resulted in high-level accumulation of the PINII protein in the transgenic plants. The introduced pin2 gene was stably inherited in the second, third, and fourth generations, as shown by molecular analyses. Based on data from the molecular analyses, several homozygous transgenic lines were obtained. Bioassay for insect resistance with the fifth-generation transgenic rice plants showed that transgenic rice plants had increased resistance to a major rice insect pest, pink stem borer (Sesamia inferens). Thus, introduction of an insecticidal proteinase inhibitor gene into cereal plants can be used as a general strategy for control of insect pests.

  7. Molecular Breeding Strategy and Challenges toward Improvement of Blast Disease Resistance in Rice Crops

    Directory of Open Access Journals (Sweden)

    Sadegh eAshkani

    2015-11-01

    Full Text Available Rice is a staple and most important security food crop consumed by almost half of the world’s population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improve blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges toward improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control.

  8. Induction of Xa10-like Genes in Rice Cultivar Nipponbare Confers Disease Resistance to Rice Bacterial Blight.

    Science.gov (United States)

    Wang, Jun; Tian, Dongsheng; Gu, Keyu; Yang, Xiaobei; Wang, Lanlan; Zeng, Xuan; Yin, Zhongchao

    2017-06-01

    Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive bacterial diseases throughout the major rice-growing regions in the world. The rice disease resistance (R) gene Xa10 confers race-specific disease resistance to X. oryzae pv. oryzae strains that deliver the corresponding transcription activator-like (TAL) effector AvrXa10. Upon bacterial infection, AvrXa10 binds specifically to the effector binding element in the promoter of the R gene and activates its expression. Xa10 encodes an executor R protein that triggers hypersensitive response and activates disease resistance. 'Nipponbare' rice carries two Xa10-like genes in its genome, of which one is the susceptible allele of the Xa23 gene, a Xa10-like TAL effector-dependent executor R gene isolated recently from 'CBB23' rice. However, the function of the two Xa10-like genes in disease resistance to X. oryzae pv. oryzae strains has not been investigated. Here, we designated the two Xa10-like genes as Xa10-Ni and Xa23-Ni and characterized their function for disease resistance to rice bacterial blight. Both Xa10-Ni and Xa23-Ni provided disease resistance to X. oryzae pv. oryzae strains that deliver the matching artificially designed TAL effectors (dTALE). Transgenic rice plants containing Xa10-Ni and Xa23-Ni under the Xa10 promoter provided specific disease resistance to X. oryzae pv. oryzae strains that deliver AvrXa10. Xa10-Ni and Xa23-Ni knock-out mutants abolished dTALE-dependent disease resistance to X. oryzae pv. oryzae. Heterologous expression of Xa10-Ni and Xa23-Ni in Nicotiana benthamiana triggered cell death. The 19-amino-acid residues at the N-terminal regions of XA10 or XA10-Ni are dispensable for their function in inducing cell death in N. benthamiana and the C-terminal regions of XA10, XA10-Ni, and XA23-Ni are interchangeable among each other without affecting their function. Like XA10, both XA10-Ni and XA23-Ni locate to the endoplasmic reticulum (ER) membrane

  9. Identification of transcription factors potential related to brown planthopper resistance in rice via microarray expression profiling

    Directory of Open Access Journals (Sweden)

    Wang Yubing

    2012-12-01

    Full Text Available Abstract Background Brown planthopper (BPH, Nilaparvata lugens Stål, is one of the most destructive insect pests of rice. The molecular responses of plants to sucking insects resemble responses to pathogen infection. However, the molecular mechanism of BPH-resistance in rice remains unclear. Transcription factors (TF are up-stream regulators of various genes that bind to specific DNA sequences, thereby controlling the transcription from DNA to mRNA. They are key regulators for transcriptional expression in biological processes, and are probably involved in the BPH-induced pathways in resistant rice varieties. Results We conducted a microarray experiment to analyze TF genes related to BPH resistance in a Sri Lankan rice cultivar, Rathu Heenati (RHT. We compared the expression profiles of TF genes in RHT with those of the susceptible rice cultivar Taichun Native 1 (TN1. We detected 2038 TF genes showing differential expression signals between the two rice varieties. Of these, 442 TF genes were probably related to BPH-induced resistance in RHT and TN1, and 229 may be related to constitutive resistance only in RHT. These genes showed a fold change (FC of more than 2.0 (P10, there were 37 induced TF genes and 26 constitutive resistance TF genes. Of these, 13 were probably involved in BPH-induced resistance, and 8 in constitutive resistance to BPH in RHT. Conclusions We explored the molecular mechanism of resistance to BPH in rice by comparing expressions of TF genes between RHT and TN1. We speculate that the level of gene repression, especially for early TF genes, plays an important role in the defense response. The fundamental point of the resistance strategy is that plants protect themselves by reducing their metabolic level to inhibit feeding by BPH and prevent damage from water and nutrient loss. We have selected 21 TF genes related to BPH resistance for further analyses to understand the molecular responses to BPH feeding in rice.

  10. Antixenosis and Antibiosis Resistance in Rice Cultivars against Chilo suppressalis (Walker) (Lepidoptera: Crambidae).

    Science.gov (United States)

    Tabari, M A; Fathi, S A A; Nouri-Ganbalani, G; Moumeni, A; Razmjou, J

    2017-08-01

    The striped stem borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), is an important pest afflicting rice in most rice-growing countries in the world. Deliniating the categories of resistance in rice genotypes under field conditions could be helpful in managment of this pest. Two categories of resistance, antixenosis and antibiosis, were examined in ten popular and diverse rice genotypes of different origin that had been selected for their resistance to the striped stem borer in a previous study. Significant differences were found between genotypes for the number of egg masses, number of eggs, preference index, larval and pupal weight, larval development time, larval survival rate, larval mine length, and leaf trichome density. It was found that the rice genotypes Novator, A7801, and Nemat had the more pronounced antixenosis-type resistance, whereas AB1 and Shirodi had better antiobiosis-type resistance. Interestingly, the rice genotype AN-74 for which Nemat is the parental line showed both types of resistance and could be effectively used in an integrated pest management of the rice striped stem borer.

  11. Geographic and research center origins of rice resistance to asian planthoppers and leafhoppers: implications for rice breeding and gene deployment

    OpenAIRE

    Horgan, F.G.; Srinivasan, Thanga Suja; Bentur, Jagadish S.; Kumar, R.; Bhanu, K.V.; Singh Sarao, Preetinder; Chien, Ho Van; Almazan, M.L.P.; Bernal, Carmencita C.; Ramal, Angelee Fame; Ferrater, J.B.; Huang, Shou Horng

    2017-01-01

    This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs) indic...

  12. Overexpressing CYP71Z2 enhances resistance to bacterial blight by suppressing auxin biosynthesis in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available The hormone auxin plays an important role not only in the growth and development of rice, but also in its defense responses. We've previously shown that the P450 gene CYP71Z2 enhances disease resistance to pathogens through regulation of phytoalexin biosynthesis in rice, though it remains unclear if auxin is involved in this process or not.The expression of CYP71Z2 was induced by Xanthomonas oryzae pv. oryzae (Xoo inoculation was analyzed by qRT-PCR, with GUS histochemical staining showing that CYP71Z2 expression was limited to roots, blades and nodes. Overexpression of CYP71Z2 in rice durably and stably increased resistance to Xoo, though no significant difference in disease resistance was detected between CYP71Z2-RNA interference (RNAi rice and wild-type. Moreover, IAA concentration was determined using the HPLC/electrospray ionization/tandem mass spectrometry system. The accumulation of IAA was significantly reduced in CYP71Z2-overexpressing rice regardless of whether plants were inoculated or not, whereas it was unaffected in CYP71Z2-RNAi rice. Furthermore, the expression of genes related to IAA, expansin and SA/JA signaling pathways was suppressed in CYP71Z2-overexpressing rice with or without inoculation.These results suggest that CYP71Z2-mediated resistance to Xoo may be via suppression of IAA signaling in rice. Our studies also provide comprehensive insight into molecular mechanism of resistance to Xoo mediated by IAA in rice. Moreover, an available approach for understanding the P450 gene functions in interaction between rice and pathogens has been provided.

  13. Insect-resistant genetically modified rice in China: from research to commercialization.

    Science.gov (United States)

    Chen, Mao; Shelton, Anthony; Ye, Gong-yin

    2011-01-01

    From the first insect-resistant genetically modified (IRGM) rice transformation in 1989 in China to October 2009 when the Chinese Ministry of Agriculture issued biosafety certificates for commercial production of two cry1Ab/Ac Bacillus thuringiensis (Bt) lines, China made a great leap forward from IRGM rice basic research to potential commercialization of the world's first IRGM rice. Research has been conducted on developing IRGM rice, assessing its environmental and food safety impacts, and evaluating its socioeconomic consequences. Laboratory and field tests have confirmed that these two Bt rice lines can provide effective and economic control of the lepidopteran complex on rice with less risk to the environment than present practices. Commercializing these Bt plants, while developing other GM plants that address the broader complex of insects and other pests, will need to be done within a comprehensive integrated pest management program to ensure the food security of China and the world.

  14. Effects of different heat-moisture treatments on the physicochemical properties of brown rice flour.

    Science.gov (United States)

    Nakamura, Sumiko; Okumura, Hisako; Sugawara, Masayoshi; Noro, Wataru; Homma, Noriyuki; Ohtsubo, Ken'ichi

    2017-12-01

    We evaluated the effect of heat-moisture treatment (HMT) on the main chemical components, physical properties, and enzyme activities of two types of brown rice flour: high-amylose Koshinokaori and normal-quality Koshiibuki. Five different HMTs using brown rice (moisture content was 12.0%) were assessed: 0.1 MPa/120 °C for 5 or 10 min, 0.2 MPa/134 °C for 5 or 10 min and 0.3 MPa/144 °C for 10 min. HMT, decreased the α-amylase and lipase activities, and fat acidity, and slightly increased the dietary fiber and resistant starch levels. After 2 months' storage at 35 °C, rice samples that were treated with 0.2 MPa/134 °C or 0.3 MPa/144 °C for 10 min had a lower fat acidity than untreated samples, which would be useful for long-term storage and export of rice flour. And HMT exhibited inhibition of retrogradation in the pasting and physical properties, which is profitable to promote the qualities of the rice products.

  15. Genetics and Improvement of Bacterial Blight Resistance of Hybrid Rice in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi

    2009-01-01

    Since 1980s, rice breeding for resistance to bacterial blight has been rapidly progressing in China. The gene Xa4 was mainly used in three-line indica hybrid and two-line hybrid rice. The disease has been 'quiet' for 20 years in China, yet in recent years it has gradually emerged and been prevalent in fields planted with newly released rice varieties in the Changjiang River valley. Under the circumstances, scientists inevitably raised several questions: what causes the resurgence and what should we do next? And/or is resistance breeding still one of the main objectives in rice improvement? Which approach do we take on resistance breeding so that the resistance will be more durable, and the resistance gene will be used more efficiently? A combined strategy involving traditional method, molecular marker-assisted selection, and transgenic technology should bring a new era to the bacterial blight resistance hybrid rice breeding program. This review also briefly discusses and deliberates on issues related to the broadening of bacterial blight resistance, and suitable utilization of resistance genes, alternate planting of available resistance genes; and understands the virulent populations of the bacterial pathogen in China even in Asia.

  16. Analysis of QTL for resistance to radiation in rice

    International Nuclear Information System (INIS)

    Zhao Fei; Zhou Yifeng; Ren Sanjuan; Fu Junjie; Zhuang Jieyun; Shen Shengquan

    2010-01-01

    The recombinant inbred line (RIL) population derived from rice variates Zhenshan 97B/Miyang 46 and their genetic linkage maps were used to map QTLs controlling resistant to radiation. The trait was measured by the relative germination rate (RGR) and the relative surviving plant rate (RSPR) after the seeds of each line treated with γ-rays irradiation at two 350 and 550 Gy. The results indicated that the lines treated with γ-irradiation showed different performance in resistance to radiation. Under the treatment of 350 Gy, two QTLs with additive effects were detected, of which qRR (g) 81 was only significant for relative germination rate, and it had the positive additive effects from the male parent, explaining 6.53% of the total phenotypic variations. The qRR(s)2-2 was another significant one for relative surviving plant rate, whose positive effects came from the female parent,explaining 12.81% of the total phenotypic variations. Similarly, 4 QTLs were detected under irradiation dose of 550 Gy, and qRR(g)1-2 and qRR(g)8-2 were detected for relative germination rate, with positive effects coming from female and male parent,respectively,explaining 14.38% of the total variations. qRR(s)5-2 and qRR(s)10 were detected for relative surviving plant rate, with positive effects coming from the male parent, explaining 19.65% of total variations. Under different irradiation dose, 9 pairs of double QTL epistasis effects could be identified in this population. The results suggested that the expression of QTL with resistance to radiation might have relation with the irradiation dose. (authors)

  17. Current Status of Conventional and Molecular Interventions for Blast Resistance in Rice

    Directory of Open Access Journals (Sweden)

    Deepti Srivastava

    2017-11-01

    Full Text Available Pyricularia oryzae anamorph of Magnaporthe oryzae is one of the most notorious fungal pathogens causing severe economic loss in rice production worldwide. Various methods, viz. cultural, biological and molecular approaches, are utilized to counteract this pathogen. Moreover, some tolerant or resistant rice varieties have been developed with the help of breeding programmes. Isolation and molecular characterization of different blast resistance genes now open the gate for new possibilities to elucidate the actual allelic variants of these genes via various molecular breeding and transgenic approaches. However, the behavioral pattern of this fungus breakups the resistance barriers in the resistant or tolerant rice varieties. This host-pathogen barrier will be possibly countered in future research by comparative genomics data from available genome sequence data of rice and M. oryzae for durable resistance. Present review emphasized fascinating recent updates, new molecular breeding approaches, transgenic and genomics approaches (i.e. miRNA and genome editing for the management of blast disease in rice. The updated information will be helpful for the durable, resistance breeding programme in rice against blast pathogen.

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

    International Nuclear Information System (INIS)

    Mathur, S.C.

    1983-01-01

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

  19. Recent progress on the genetics and molecular breeding of brown planthopper resistance in rice.

    Science.gov (United States)

    Hu, Jie; Xiao, Cong; He, Yuqing

    2016-12-01

    Brown planthopper (BPH) is the most devastating pest of rice. Host-plant resistance is the most desirable and economic strategy in the management of BPH. To date, 29 major BPH resistance genes have been identified from indica cultivars and wild rice species, and more than ten genes have been fine mapped to chromosome regions of less than 200 kb. Four genes (Bph14, Bph26, Bph17 and bph29) have been cloned. The increasing number of fine-mapped and cloned genes provide a solid foundation for development of functional markers for use in breeding. Several BPH resistant introgression lines (ILs), near-isogenic lines (NILs) and pyramided lines (PLs) carrying single or multiple resistance genes were developed by marker assisted backcross breeding (MABC). Here we review recent progress on the genetics and molecular breeding of BPH resistance in rice. Prospect for developing cultivars with durable, broad-spectrum BPH resistance are discussed.

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

    International Nuclear Information System (INIS)

    Zhang Jingxin; Sun Dayuan; Wang Hui; Liu Yongzhu; Guo Tao; Chen Zhiqiang; Yang Qiyun; Zhu Xiaoyuan

    2012-01-01

    To screen the blast resistance mutants, the resistance of SP 1 progenies derived from rice variety Taihang-68 were evaluated after satellite flight by representative blast isolate GD0193 which had a broad pathogenic spectra, and then primary genetic analysis of resistant mutants and mapping of resistance gene, as well as resistance spectra at seedling and neck blast resistance at maturity were performed. The results showed that space-mutation was effective method to change the blast resistance of Taihang-68. The screened resistant mutants TH1 and TH2 showed that resistance to isolate GD0193 no disjunction and separation respectively, and the resistance separation ratio of TH2 indicated that its resistance was controlled by one pair of major genes, which was preliminary mapped on the long arm of chromosome 11. In blast resistance spectra and neck blast resistance, TH1 and TH2 were both enhanced remarkable compared with the wild-type at seedling and maturity, and their resistance could be inherited, the blast resistance of these two mutants were also increased comparing with several main cultivars in South China. (authors)

  1. Prospects of Understanding the Molecular Biology of Disease Resistance in Rice

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Singh

    2018-04-01

    Full Text Available Rice is one of the important crops grown worldwide and is considered as an important crop for global food security. Rice is being affected by various fungal, bacterial and viral diseases resulting in huge yield losses every year. Deployment of resistance genes in various crops is one of the important methods of disease management. However, identification, cloning and characterization of disease resistance genes is a very tedious effort. To increase the life span of resistant cultivars, it is important to understand the molecular basis of plant host–pathogen interaction. With the advancement in rice genetics and genomics, several rice varieties resistant to fungal, bacterial and viral pathogens have been developed. However, resistance response of these varieties break down very frequently because of the emergence of more virulent races of the pathogen in nature. To increase the durability of resistance genes under field conditions, understanding the mechanismof resistance response and its molecular basis should be well understood. Some emerging concepts like interspecies transfer of pattern recognition receptors (PRRs and transgenerational plant immunitycan be employed to develop sustainable broad spectrum resistant varieties of rice.

  2. Use of molecular markers in identification and characterization of resistance to rice blast in India.

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Yadav

    Full Text Available Rice blast disease caused by Magnaporthe oryzae is one of the most destructive disease causing huge losses to rice yield in different parts of the world. Therefore, an attempt has been made to find out the resistance by screening and studying the genetic diversity of eighty released rice varieties by National Rice Research Institute, Cuttack (NRVs using molecular markers linked to twelve major blast resistance (R genes viz Pib, Piz, Piz-t, Pik, Pik-p, Pikm Pik-h, Pita/Pita-2, Pi2, Pi9, Pi1 and Pi5. Out of which, nineteen varieties (23.75% showed resistance, twenty one were moderately resistant (26.25% while remaining forty varieties (50% showed susceptible in uniform blast nursery. Rice varieties possessing blast resistance genes varied from four to twelve and the frequencies of the resistance genes ranged from 0 to 100%. The cluster analysis grouped the eighty NRVs into two major clusters at 63% level of genetic similarity coefficient. The PIC value for seventeen markers varied from 0 to 0.37 at an average of 0.20. Out of seventeen markers, only five markers, 195R-1, Pi9-i, Pita3, YL155/YL87 and 40N23r corresponded to three broad spectrum R genes viz. Pi9, Pita/Pita2 and Pi5 were found to be significantly associated with the blast disease with explaining phenotypic variance from 3.5% to 7.7%. The population structure analysis and PCoA divided the entire 80 NRVs into two sub-groups. The outcome of this study would help to formulate strategies for improving rice blast resistance through genetic studies, plant-pathogen interaction, identification of novel R genes, development of new resistant varieties through marker-assisted breeding for improving rice blast resistance in India and worldwide.

  3. Use of molecular markers in identification and characterization of resistance to rice blast in India.

    Science.gov (United States)

    Yadav, Manoj Kumar; S, Aravindan; Ngangkham, Umakanta; Shubudhi, H N; Bag, Manas Kumar; Adak, Totan; Munda, Sushmita; Samantaray, Sanghamitra; Jena, Mayabini

    2017-01-01

    Rice blast disease caused by Magnaporthe oryzae is one of the most destructive disease causing huge losses to rice yield in different parts of the world. Therefore, an attempt has been made to find out the resistance by screening and studying the genetic diversity of eighty released rice varieties by National Rice Research Institute, Cuttack (NRVs) using molecular markers linked to twelve major blast resistance (R) genes viz Pib, Piz, Piz-t, Pik, Pik-p, Pikm Pik-h, Pita/Pita-2, Pi2, Pi9, Pi1 and Pi5. Out of which, nineteen varieties (23.75%) showed resistance, twenty one were moderately resistant (26.25%) while remaining forty varieties (50%) showed susceptible in uniform blast nursery. Rice varieties possessing blast resistance genes varied from four to twelve and the frequencies of the resistance genes ranged from 0 to 100%. The cluster analysis grouped the eighty NRVs into two major clusters at 63% level of genetic similarity coefficient. The PIC value for seventeen markers varied from 0 to 0.37 at an average of 0.20. Out of seventeen markers, only five markers, 195R-1, Pi9-i, Pita3, YL155/YL87 and 40N23r corresponded to three broad spectrum R genes viz. Pi9, Pita/Pita2 and Pi5 were found to be significantly associated with the blast disease with explaining phenotypic variance from 3.5% to 7.7%. The population structure analysis and PCoA divided the entire 80 NRVs into two sub-groups. The outcome of this study would help to formulate strategies for improving rice blast resistance through genetic studies, plant-pathogen interaction, identification of novel R genes, development of new resistant varieties through marker-assisted breeding for improving rice blast resistance in India and worldwide.

  4. Differences in phytoalexin response among rice cultivars of different resistance to blast

    International Nuclear Information System (INIS)

    Dillon, V.M.; Overton, J.; Grayer, R.J.; Harborne, J.B.

    1997-01-01

    he production of both flavonoid and diterpenoid phytoalexins after induction by UV irradiation was studied in five rice genotypes of different susceptibility to the rice blast fungus Pyricularia oryzae. Consistent qualitative and quatitative differences were found between the rice cultivars in the phytoalexins produced, and there was a strong correlation between the accumulation of the phytoalexins, sakuranetin, momilactone A and oryzalexin S, and rice resistance to blast. Production of phytoalexins was also investigated in rice genotype Tetep after inoculation with an incompatible race of P. oryzae. Similar levels of sakuranetin and oryzalexin E were formed 3 days after both inoculation and UV irradiation of the leaves, but there were different levels of momilactone A and the other oryzalexins. Although a given rice genotype may respond quite differently in its production of phytoalexins depending on whether it has been irradiated or inoculated with a fungus, and in the latter case on whether a compatible race of the pathogen has been used, the present results indicate that genetic differences in phytoalexin response between rice cultivars are likely to play an important role among the many factors that determine differences in blast resistance between different rice genotypes. (author)

  5. The improvement of rice varieties for major pest and diseases resistance

    International Nuclear Information System (INIS)

    Sahi, I.; Silitonga, T.S.

    1988-01-01

    Since 1971, the rice breeding program in Indonesia has developed on intensive program to improve varieties for yield potential, resistancy to major pests and diseases, early maturity good grain and eating quality. In recent years, the attacks of insects and diseases are very severe in rice cultivation in Asia. Much of the losses were due to acontinuous planting or certain varieties. Between 1966 and 1973 tungro occured in epidemic proportions on separate occasions in Indonesia, Thailand, Nort East India, Bangladesh, and Philippine. Since 1973, investation of brown planthopper and green leafhopper several damaged rice crop in most parts of Indonesia. Presently, rice improvement are directed to develop high yielding rice varieties that are resistant to brown planthopper, ragged stunt virus, blast, green leafhopper, and gallmidge. Screening for pests and diseases are conducted in the laboratory as well as in the field. The adoption of those improved varieties by farmers has contributed greatly in our efforts to attain self sufficiency in rice production in Indonesia. GH 147 -M-40 krad-Pn-89 (irradiated Barito) showed resistant to brown planthopper biotype 1 and 2 and moderately resistant to biotype 3. Napa 40 krad-St-12 has resistant reaction to blast. (authors). 4 refs, 8 tabs

  6. Jasmonate induction of the monoterpene linalool confers resistance to rice bacterial blight and its biosynthesis is regulated by JAZ protein in rice.

    Science.gov (United States)

    Taniguchi, Shiduku; Hosokawa-Shinonaga, Yumi; Tamaoki, Daisuke; Yamada, Shoko; Akimitsu, Kazuya; Gomi, Kenji

    2014-02-01

    Jasmonic acid (JA) is involved in the regulation of host immunity in plants. Recently, we demonstrated that JA signalling has an important role in resistance to rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice. Here, we report that many volatile compounds accumulate in response to exogenous application of JA, including the monoterpene linalool. Expression of linalool synthase was up-regulated by JA. Vapour treatment with linalool induced resistance to Xoo, and transgenic rice plants overexpressing linalool synthase were more resistance to Xoo, presumably due to the up-regulation of defence-related genes in the absence of any treatment. JA-induced accumulation of linalool was regulated by OsJAZ8, a rice jasmonate ZIM-domain protein involving the JA signalling pathway at the transcriptional level, suggesting that linalool plays an important role in JA-induced resistance to Xoo in rice. © 2013 John Wiley & Sons Ltd.

  7. Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3∶1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

  8. Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium -mediated system

    Institute of Scientific and Technical Information of China (English)

    翟文学; 李晓兵; 田文忠; 周永力; 潘学彪; 曹守云; 赵显峰; 赵彬; 章琦; 朱立煌

    2000-01-01

    A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3 : 1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transfor-mants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

  9. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus

    Directory of Open Access Journals (Sweden)

    Fangquan Wang

    2016-05-01

    Full Text Available Rice black-streaked dwarf virus (RBSDV belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21–24 nt small interfering RNA (siRNA. By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.

  10. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus.

    Science.gov (United States)

    Wang, Fangquan; Li, Wenqi; Zhu, Jinyan; Fan, Fangjun; Wang, Jun; Zhong, Weigong; Wang, Ming-Bo; Liu, Qing; Zhu, Qian-Hao; Zhou, Tong; Lan, Ying; Zhou, Yijun; Yang, Jie

    2016-05-11

    Rice black-streaked dwarf virus (RBSDV) belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA) construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21-24 nt small interfering RNA (siRNA). By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.

  11. Methyl jasmonate induced resistance in cheniere rice and soybean plants

    Science.gov (United States)

    Taplin, C.

    2017-12-01

    Methyl jasmonate (MJ) is a compound naturally occurring in certain plants that aids in plant defense. In this study, we examined the difference in herbivory of fall armyworm (FAW) on control plants (treated without MJ) and MJ-treated plants. Seeds of cheniere rice and soybean were soaked in MJ overnight and planted in the greenhouse, although the soybean never grew. Therefore, only the mature plant leaves of cheniere rice were fed to FAW and the difference in herbivory was looked at. Our results show there is no statistical difference in the herbivory of the cheniere rice plant leaves.

  12. Engineering the lodging resistance mechanism of post-Green Revolution rice to meet future demands.

    Science.gov (United States)

    Hirano, Ko; Ordonio, Reynante Lacsamana; Matsuoka, Makoto

    2017-01-01

    Traditional breeding for high-yielding rice has been dependent on the widespread cultivation of gibberellin (GA)-deficient semi-dwarf varieties. Dwarfism lowers the "center of gravity" of the plant body, which increases resistance against lodging and enables plants to support high grain yield. Although this approach was successful in latter half of the 20th century in rice and wheat breeding, this may no longer be enough to sustain rice with even higher yields. This is because relying solely on the semi-dwarf trait is subject to certain limitations, making it necessary to use other important traits to reinforce it. In this review, we present an alternative approach to increase lodging resistance by improving the quality of the culm by identifying genes related to culm quality and introducing these genes into high-yielding rice cultivars through molecular breeding technique.

  13. Molecular mapping of qBK1 WD , a major QTL for bakanae disease resistance in rice

    OpenAIRE

    Lee, Sais-Beul; Hur, Yeon-Jae; Cho, Jun-Hyeon; Lee, Jong-Hee; Kim, Tae-Heon; Cho, Soo-Min; Song, You-Chun; Seo, Young-Su; Lee, Jungkwan; Kim, Tae-sung; Park, Yong-Jin; Oh, Myung-Kyu; Park, Dong-Soo

    2018-01-01

    Background Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring ba...

  14. Identification of transcription factors potential related to brown planthopper resistance in rice via microarray expression profiling.

    Science.gov (United States)

    Wang, Yubing; Guo, Huimin; Li, Haichao; Zhang, Hao; Miao, Xuexia

    2012-12-10

    Brown planthopper (BPH), Nilaparvata lugens Stål, is one of the most destructive insect pests of rice. The molecular responses of plants to sucking insects resemble responses to pathogen infection. However, the molecular mechanism of BPH-resistance in rice remains unclear. Transcription factors (TF) are up-stream regulators of various genes that bind to specific DNA sequences, thereby controlling the transcription from DNA to mRNA. They are key regulators for transcriptional expression in biological processes, and are probably involved in the BPH-induced pathways in resistant rice varieties. We conducted a microarray experiment to analyze TF genes related to BPH resistance in a Sri Lankan rice cultivar, Rathu Heenati (RHT). We compared the expression profiles of TF genes in RHT with those of the susceptible rice cultivar Taichun Native 1 (TN1). We detected 2038 TF genes showing differential expression signals between the two rice varieties. Of these, 442 TF genes were probably related to BPH-induced resistance in RHT and TN1, and 229 may be related to constitutive resistance only in RHT. These genes showed a fold change (FC) of more than 2.0 (Pgenes related to BPH-induced resistance, most of them were readily induced in TN1 than in RHT by BPH feeding, for instance, 154 TF genes were up-regulated in TN1, but only 31 TF genes were up-regulated in RHT at 24 hours after BPH infestation; 2-4 times more TF genes were induced in TN1 than in RHT by BPH. At an FC threshold of >10, there were 37 induced TF genes and 26 constitutive resistance TF genes. Of these, 13 were probably involved in BPH-induced resistance, and 8 in constitutive resistance to BPH in RHT. We explored the molecular mechanism of resistance to BPH in rice by comparing expressions of TF genes between RHT and TN1. We speculate that the level of gene repression, especially for early TF genes, plays an important role in the defense response. The fundamental point of the resistance strategy is that plants

  15. Physical Characterization Of High Amylose/Pectin Mixtures Cross-Linked With Sodium Trimetaphosphate; Caracterizacao fisica de misturas alta amilose/pectina reticuladas com trimetafosfato de sodio

    Energy Technology Data Exchange (ETDEWEB)

    Carbinatto, F.M.; Cury, B.S.F.; Evangelista, R.C., E-mail: curybsf@fcfar.unesp.b [UNESP, Araraquara, SP (Brazil). Fac. de Ciencias Farmaceuticas

    2010-07-01

    Some researches have reported that pectin and high amylose mixtures presented superior mechanical properties in relation to those of the isolated polymers. In this work, mixtures at different ratios (1:4; 1:1) of pectin and high amylose were crosslinked with sodium trimetaphosphate at different degrees by varying reaction conditions. All samples were characterized by rheological and X-ray diffraction analyses. Samples without cross-linker were prepared as control. The oscillatory dynamic tests showed that all samples exhibited predominant elastic behavior, although cross-linked samples presented higher G' values, suggesting that crosslinking by phosphorylation resulted in more strength structures. The diffractograms showed that cross-linked samples underwent structural modifications that resulted in increase of crystallinity due to cross-linking process. (author)

  16. Comparison of phenotyping methods for resistance to stem rot and aggregated sheath spot in rice

    Science.gov (United States)

    Stem and sheath diseases caused by Sclerotium oryzae Cattaneo (SCL) and Rhizoctonia oryzae-sativae Sawada Mordue (ROS) can severely reduce rice (Oryza sativa L.) yield and grain quality. Genetic resistance is the best strategy to control them. Phenotypic selection for resistance is hampered due to a...

  17. Comparative Proteomic Analysis of Susceptible and Resistant Rice Plants during Early Infestation by Small Brown Planthopper

    Directory of Open Access Journals (Sweden)

    Yan Dong

    2017-10-01

    Full Text Available The small brown planthopper (Laodelphax striatellus Fallén, Homoptera, Delphacidae-SBPH is one of the major destructive pests of rice (Oryza sativa L.. Understanding on how rice responds to SBPH infestation will contribute to developing strategies for SBPH control. However, the response of rice plant to SBPH is poorly understood. In this study, two contrasting rice genotypes, Pf9279-4 (SBPH-resistant and 02428 (SBPH-susceptible, were used for comparative analysis of protein profiles in the leaf sheath of rice plants in responses to SBPH infestation. One hundred and thirty-two protein spots that were differentially expressed between the resistant and susceptible rice lines were identified with significant intensity differences (≥2-fold, P < 0.05 at 0, 6, and 12 h after SBPH infestation. Protein expression profile analysis in the leaf sheath of SBPH-resistant and SBPH-susceptible rice lines after SBPH infestation showed that proteins induced by SBPH feeding were involved mainly in stress response, photosynthesis, protein metabolic process, carbohydrate metabolic process, energy metabolism, cell wall-related proteins, amino acid metabolism and transcriptional regulation. Gene expression analysis of 24 differentially expressed proteins (DEPs showed that more than 50% DEPs were positively correlated with their mRNA levels. Analysis of some physiological indexes mainly involved in the removal of oxygen reactive species showed that the levels of superoxide dismutase (SOD and glutathione (GSH were considerably higher in Pf9279-4 than 02428 during SBPH infestation. The catalase (CAT activity and hydroxyl radical inhibition were lower in Pf9279-4 than 02428. Analysis of enzyme activities indicates that Pf9279-4 rice plants defend against SBPH through the activation of the pathway of the salicylic acid (SA-dependent systemic acquired resistance. In conclusion, this study provides some insights into the molecular networks involved on cellular and

  18. Two whitebacked planthopper resistance genes in rice share the same loci with those for brown planthopper resistance.

    Science.gov (United States)

    Tan, G X; Weng, Q M; Ren, X; Huang, Z; Zhu, L L; He, G C

    2004-03-01

    The whitebacked planthopper (WBPH), Sogatella furcifera, and brown planthopper (BPH) Nilaparvata lugens Stål are important sucking insects of rice (Oryza sativa L.) crops throughout the world. Rice 'B5', which has derived its resistance genes from the wild rice O. officinalis Wall ex Watt, is a line that is highly resistant to both WBPH and BPH. Previously, two resistance genes against BPH, Qbp1, and Qbp2 in 'B5' had been mapped onto chromosome 3 and chromosome 4, respectively. In this study, we employed a mapping population composed of 187 recombinant inbred lines (RILs), produced from a cross between 'B5' and susceptible variety 'Minghui63', to locate the WBPH and BPH resistance genes. A RFLP survey of the bulked extremes from the RIL population identified two genomic regions, one on chromosome 3 and the other on chromosome 4, likely containing the resistance genes to planthoppers. QTL analysis of the RILs further confirmed that two WBPH resistance genes were mapped on the same loci as Qbp1 and Qbp2, using a linkage map with 242 molecular markers distributed on 12 rice chromosomes. Of the two WBPH resistance genes, one designated Wbph7(t) was located within a 1.1-cM region between R1925 and G1318 on chromosome 3, the other designated Wbph8(t) was within a 0.3-cM region flanked by R288 and S11182 on chromosome 4. A two-way analysis of variance showed that two loci acted independently with each other in determining WBPH resistance. The results have significant implications in studying the interactions between sucking insects and plants and in breeding programs of resistance to rice planthoppers.

  19. Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus

    Science.gov (United States)

    Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, César P.; Calvert, Lee; Lorieux, Mathias

    2013-01-01

    Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

  20. Physical mapping of Bph3, a brown planthopper resistance locus in rice

    Directory of Open Access Journals (Sweden)

    Jirapong Jairin

    2007-09-01

    Full Text Available Resistance to brown planthopper (BPH, a destructive phloem feeding insect pest, is an important objective in rice breeding programs in Thailand. The broad-spectrum resistance gene Bph3 is one of the major BPH resistance genes identified so far in cultivated rice and has been widely used in rice improvement programs. This resistance gene has been identified and mapped on the short arm of chromosome 6. In this study, physical mapping of Bph3 was performed using a BC3F3 population derived from a cross between Rathu Heenati and KDML105. Recombinant BC3F3 individuals with the Bph3 genotype were determined by phenotypic evaluation using modified mass tiller screening at the vegetative stage of rice plants. The recombination events surrounding the Bph3 locus were used to identify the co-segregate markers. According to the genome sequence of Nipponbare, the Bph3 locus was finally localized approximately in a 190 kb interval flanked by markers RM19291 and RM8072, which contain twenty-two putative genes. Additional phenotypic experiment revealed that the resistance in Rathu Heenati was decreased by increasing nitrogen content in rice plants through remobilization of nitrogen. This phenomenon should be helpful for identifying the Bph3 gene.

  1. Silencing OsSLR1 enhances the resistance of rice to the brown planthopper Nilaparvata lugens.

    Science.gov (United States)

    Zhang, Jin; Luo, Ting; Wang, Wanwan; Cao, Tiantian; Li, Ran; Lou, Yonggen

    2017-10-01

    DELLA proteins, negative regulators of the gibberellin (GA) pathway, play important roles in plant growth, development and pathogen resistance by regulating multiple phytohormone signals. Yet, whether and how they regulate plant herbivore resistance remain unknown. We found that the expression of the rice DELLA gene OsSLR1 was down-regulated by an infestation of female adults of the brown planthopper (BPH) Nilaparvata lugens. On one hand, OsSLR1 positively regulated BPH-induced levels of two mitogen-activated protein kinase and four WRKY transcripts, and of jasmonic acid, ethylene and H 2 O 2 . On the other hand, silencing OsSLR1 enhanced constitutive levels of defence-related compounds, phenolic acids, lignin and cellulose, as well as the resistance of rice to BPH in the laboratory and in the field. The increased resistance in rice with silencing of OsSLR1 is probably due to impaired JA and ethylene pathways, and, at least in part, to the increased lignin level and mechanical hardness of rice leaf sheaths. Our findings illustrate that OsSLR1, acting as an early negative regulator, plays an important role in regulating the resistance of rice to BPH by activating appropriate defence-related signalling pathways and compounds. Moreover, our data also provide new insights into relationships between plant growth and defence. © 2017 John Wiley & Sons Ltd.

  2. Crown sheath rot of rice: host-range and varietal resistance to Gaeumannomyces graminis var. graminis

    Directory of Open Access Journals (Sweden)

    Cecília do Nascimento Peixoto

    2014-09-01

    Full Text Available Several gramineous plants occurring in rice fields show symptoms of crown sheath rot of rice, caused by Gaeumannomyces graminis var. graminis (Ggg, under natural conditions of infection. The pathogenicity of the Ggg-a 01 isolate, collected from rice, was tested on seven grass species and eight cereals, under greenhouse conditions, in order to get information on host-range and resistance of rice genotypes to crown sheath rot. The inoculation tests showed that the rice isolate was pathogenic to weeds such as Echinochloa crusgalli, Pennisetum setosum, Brachiaria sp., Digitaria horizontalis, Brachiaria plantaginea, Eleusine indica and Cenchrus echinatus, and that these species are potential hosts to the pathogen. Winter cereals such as wheat, oat, rye, barley and triticale, as well as sorghum, maize and millet, presented different degrees of susceptibility to the Ggg-a isolate. Significant differences were observed in relation to lesion height and production of hyphopodia and perithecia on culms. Perithecia were not observed on millet, sorghum, southern sandbur and maize. The resistance of 58 upland rice genotypes was tested, and the SCIA16 and SCIA08 genotypes presented lesion height significantly smaller, being considered resistant, when compared to the highly susceptible CNAS10351 genotype.

  3. Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

    Science.gov (United States)

    Ning, Dongfeng; Song, Alin; Fan, Fenliang; Li, Zhaojun; Liang, Yongchao

    2014-01-01

    It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.

  4. Genetic mapping of the rice resistance-breaking gene of the brown planthopper Nilaparvata lugens.

    Science.gov (United States)

    Kobayashi, Tetsuya; Yamamoto, Kimiko; Suetsugu, Yoshitaka; Kuwazaki, Seigo; Hattori, Makoto; Jairin, Jirapong; Sanada-Morimura, Sachiyo; Matsumura, Masaya

    2014-07-22

    Host plant resistance has been widely used for controlling the major rice pest brown planthopper (BPH, Nilaparvata lugens). However, adaptation of the wild BPH population to resistance limits the effective use of resistant rice varieties. Quantitative trait locus (QTL) analysis was conducted to identify resistance-breaking genes against the anti-feeding mechanism mediated by the rice resistance gene Bph1. QTL analysis in iso-female BPH lines with single-nucleotide polymorphism (SNP) markers detected a single region on the 10th linkage group responsible for the virulence. The QTL explained from 57 to 84% of the total phenotypic variation. Bulked segregant analysis with next-generation sequencing in F2 progenies identified five SNPs genetically linked to the virulence. These analyses showed that virulence to Bph1 was controlled by a single recessive gene. In contrast to previous studies, the gene-for-gene relationship between the major resistance gene Bph1 and virulence gene of BPH was confirmed. Identified markers are available for map-based cloning of the major gene controlling BPH virulence to rice resistance. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  5. A maize resistance gene functions against bacterial streak disease in rice.

    Science.gov (United States)

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-10-25

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, which causes bacterial streak disease. Bacterial streak is an important disease of rice in Asia, and no simply inherited sources of resistance have been identified in rice. Although X. o. pv. oryzicola does not cause disease on maize, we identified a maize gene, Rxo1, that conditions a resistance reaction to a diverse collection of pathogen strains. Surprisingly, Rxo1 also controls resistance to the unrelated pathogen Burkholderia andropogonis, which causes bacterial stripe of sorghum and maize. The same gene thus controls resistance reactions to both pathogens and nonpathogens of maize. Rxo1 has a nucleotide-binding site-leucine-rich repeat structure, similar to many previously identified R genes. Most importantly, Rxo1 functions after transfer as a transgene to rice, demonstrating the feasibility of nonhost R gene transfer between cereals and providing a valuable tool for controlling bacterial streak disease.

  6. Evaluation of Rice Resistance to Southern Rice Black-Streaked Dwarf Virus and Rice Ragged Stunt Virus through Combined Field Tests, Quantitative Real-Time PCR, and Proteome Analysis.

    Science.gov (United States)

    Wang, Zhenchao; Yu, Lu; Jin, Linhong; Wang, Wenli; Zhao, Qi; Ran, Longlu; Li, Xiangyang; Chen, Zhuo; Guo, Rong; Wei, Yongtian; Yang, Zhongcheng; Liu, Enlong; Hu, Deyu; Song, Baoan

    2017-02-22

    Diseases caused by southern rice black-streaked dwarf virus (SRBSDV) and rice ragged stunt virus (RRSV) considerably decrease grain yield. Therefore, determining rice cultivars with high resistance to SRBSDV and RRSV is necessary. In this study, rice cultivars with high resistance to SRBSDV and RRSV were evaluated through field trials in Shidian and Mangshi county, Yunnan province, China. SYBR Green I-based quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to quantitatively detect virus gene expression levels in different rice varieties. The following parameters were applied to evaluate rice resistance: acre yield (A.Y.), incidence of infected plants (I.I.P.), virus load (V.L.), disease index (D.I.), and insect quantity (I.Q.) per 100 clusters. Zhongzheyou1 (Z1) and Liangyou2186 (L2186) were considered the most suitable varieties with integrated higher A.Y., lower I.I.P., V.L., D.I. and I.Q. In order to investigate the mechanism of rice resistance, comparative label-free shotgun liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomic approaches were applied to comprehensively describe the proteomics of rice varieties' SRBSDV tolerance. Systemic acquired resistance (SAR)-related proteins in Z1 and L2186 may result in the superior resistance of these varieties compared with Fengyouxiangzhan (FYXZ).

  7. Altered Tuber Yield in Genetically Modified High-Amylose and Oil Potato Lines Is Associated With Changed Whole-Plant Nitrogen Economy

    Directory of Open Access Journals (Sweden)

    Fereshteh Pourazari

    2018-03-01

    Full Text Available Breeding for improved crop quality traits can affect non-target traits related to growth and resource use, and these effects may vary in different cultivation conditions (e. g., greenhouse vs. field. The objectives of this study are to investigate the growth and whole-plant nitrogen (N economy of two genetically modified (GM potato lines compared to their non-GM parental varieties and when grown in different cultivation conditions. A high-amylose GM potato line and its parent were grown under field and greenhouse conditions for one growing season in Sweden; and a GM oil potato line and its parent were grown in greenhouse conditions only. Tuber yield, above ground biomass, N uptake efficiency and other plant N economy traits were assessed. In both cultivation conditions, the GM lines produced between 1.5 and two times more tubers as compared with their parents. In the greenhouse, fresh tuber yield and N uptake efficiency were unaffected by the genetic modifications, but the GM-lines produced less tuber biomass per plant-internal N compared to their parents. In the field, the fresh tuber yield was 40% greater in the high-amylose line as compared with its parent; the greater fresh tuber yield in the high-amylose GM line was accomplished by higher water allocation to the harvested tubers, and associated with increased N recovery from soil (+20%, N uptake efficiency (+53%, tuber N content (+20%, and N accumulation (+120% compared with the non-GM parent. The cultivation conditions influenced the yield and N economy. For example, the final fresh above-ground plant biomass and N pool were considerably higher in the greenhouse conditions, whilst the tuber yield was higher in the field conditions. In conclusion, the genetic modification inducing high accumulation of amylose in potato tubers affected several non-target traits related to plant N economy, and increased the plant N uptake and accumulation efficiency of the field-grown plants. Due to strongly

  8. Altered Tuber Yield in Genetically Modified High-Amylose and Oil Potato Lines Is Associated With Changed Whole-Plant Nitrogen Economy.

    Science.gov (United States)

    Pourazari, Fereshteh; Andersson, Mariette; Weih, Martin

    2018-01-01

    Breeding for improved crop quality traits can affect non-target traits related to growth and resource use, and these effects may vary in different cultivation conditions (e. g., greenhouse vs. field). The objectives of this study are to investigate the growth and whole-plant nitrogen (N) economy of two genetically modified (GM) potato lines compared to their non-GM parental varieties and when grown in different cultivation conditions. A high-amylose GM potato line and its parent were grown under field and greenhouse conditions for one growing season in Sweden; and a GM oil potato line and its parent were grown in greenhouse conditions only. Tuber yield, above ground biomass, N uptake efficiency and other plant N economy traits were assessed. In both cultivation conditions, the GM lines produced between 1.5 and two times more tubers as compared with their parents. In the greenhouse, fresh tuber yield and N uptake efficiency were unaffected by the genetic modifications, but the GM-lines produced less tuber biomass per plant-internal N compared to their parents. In the field, the fresh tuber yield was 40% greater in the high-amylose line as compared with its parent; the greater fresh tuber yield in the high-amylose GM line was accomplished by higher water allocation to the harvested tubers, and associated with increased N recovery from soil (+20%), N uptake efficiency (+53%), tuber N content (+20%), and N accumulation (+120%) compared with the non-GM parent. The cultivation conditions influenced the yield and N economy. For example, the final fresh above-ground plant biomass and N pool were considerably higher in the greenhouse conditions, whilst the tuber yield was higher in the field conditions. In conclusion, the genetic modification inducing high accumulation of amylose in potato tubers affected several non-target traits related to plant N economy, and increased the plant N uptake and accumulation efficiency of the field-grown plants. Due to strongly increased

  9. A maize resistance gene functions against bacterial streak disease in rice

    OpenAIRE

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-01-01

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, wh...

  10. Induction of resistance to rice tungro virus disease in rice cultivar Pusa 2-21 through irradiation

    International Nuclear Information System (INIS)

    Mathur, S.C.; Rao, M.; Prakash, Jitendra

    1979-01-01

    The dry seeds of Pusa 2-21, a moderately resistant rice cultivar, were subjected to 10, 15 and 20 Krad (dose rate 12.3 Krad/min) radiation dosages of gamma rays to induce resistance against rice tungro virus disease. The height of M 1 seedling was significantly reduced in 15 and 20 Krad treatments. However, there was no effect of gamma irradiation on seed germination. A limited population of M 2 and M 3 generation was screened at the rate of 3 viruliferous leafhoppers/seedling using single plant caging technique. In M 2 generation 22.0, 17.6 and 25.0 percent seedlings exhibited green colour (symptomless) representing resistant reaction to the disease in 10, 15 and 20 Krad treatments, respectively. Out of 1470 seedlings in M 3 generation, 2.7 percent seedlings showing no symptoms of tungro could be isolated indicating the possibility of inducing higher degree of resistance than that of the parent to RTV through irradiation for the first time. (auth.)

  11. DNA tagging of blast resistant gene(s in three Brazilian rice cultivars

    Directory of Open Access Journals (Sweden)

    S.S. Sandhu

    2003-12-01

    Full Text Available Rice blast is the most important fungal disease of rice and is caused by Pyricularia oryzae Sacc. (Telomorph Magnoporthe grisea Barr.. Seven randomly amplified polymorphic DNA (RAPD markers OPA5, OPG17, OPG18, OPG19, OPF9, OPF17 and OPF19 showed very clear polymorphism in resistant cultivar lines which differed from susceptible lines. By comparing different susceptible lines, nine DNA amplifications of seven primers (OPA5(1000, OPA5(1200, OPG17(700, OPG18(850, OPG19(500, OPG19(600, OPF9(600, OPF17(1200 and OPF19(600 were identified as dominant markers for the blast resistant gene in resistant cultivar lines. These loci facilitate the indirect scoring of blast resistant and blast susceptible genotypes. The codomine RAPDs markers will facilitate marker-assisted selection of the blast resistant gene in two blast resistant genotypes of rice (Labelle and Line 11 and will be useful in rice breeding programs.

  12. Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice

    Directory of Open Access Journals (Sweden)

    Tilak R. Sharma

    2017-04-01

    Full Text Available Sheath blight disease (ShB, caused by the fungus Rhizoctonia solani Kühn, is one of the most destructive diseases of rice (Oryza sativa L., causing substantial yield loss in rice. In the present study, a novel rice chitinase gene, LOC_Os11g47510 was cloned from QTL region of R. solani tolerant rice line Tetep and used for functional validation by genetic transformation of ShB susceptible japonica rice line Taipei 309 (TP309. The transformants were characterized using molecular and functional approaches. Molecular analysis by PCR using a set of primers specific to CaMv 35S promoter, chitinase and HptII genes confirmed the presence of transgene in transgenic plants which was further validated by Southern hybridization. Further, qRT-PCR analysis of transgenic plants showed good correlation between transgene expression and the level of sheath blight resistance among transformants. Functional complementation assays confirmed the effectiveness of the chitinase mediated resistance in all the transgenic TP309 plants with varying levels of enhanced resistance against R. solani. Therefore, the novel chitinase gene cloned and characterized in the present study from the QTL region of rice will be of significant use in molecular plant breeding program for developing sheath blight resistance in rice.

  13. Blast resistance of space-induced variants derived from rice cultivar Hanghui 7

    International Nuclear Information System (INIS)

    Zhang Jingxin; Yang Qiyun; Zhu Xiaoyuan; Wang Hui; Zeng Liexian; Liu Yongzhu; Guo Tao; Chen Zhiqiang

    2010-01-01

    To screen the resistance lines to rice blast, the blast resistance of SP 3 and SP 4 progenies derived from rice variety Hanghui 7 were evaluated after satellite flight, and the genomic DNA polymorphism of the resistant variants selected from SP 3 was compared with the wild type by microsatellite markers. The results indicated that the SP 3 Variant line H24, which was selected from the 250 space-induced lines ( SP 3 ) with excellent agronomic and economical characters, showed resistance segregation (119R : 108S) against blast isolate GD3286. It was demonstrated that the resistance of H24 might be controlled by two dominant and complementary resistance genes. The resistance of H24 was still segregated in SP 4 , but the resistance spectrum of H24 was 84. 4% in SP 5 , much higher than the wild type, 40. 6%, and H24 especially showed resistant against some blast isolates of broad pathogenic spectrum or specialized pathogenicity; further more, the DNA polymorphism wasn't detected between H24 and its wild type by 229 SSR (simple sequence repeat) markers covering the rice genome equally. (authors)

  14. Association nitrogen fixation of rice inoculated with ammonia resistant engineering strain (alcaligenes faecalis)

    International Nuclear Information System (INIS)

    Chen Ming; Zhang Wei; Lin Min

    1999-01-01

    It showed that Alcaligenes faecalis could produce plant hormone (IAA) in LW medium. The pot experiment results showed that inoculation with A1501 and A1513 could promote the growth and grain yield of rice. Comparison with the non-inoculation, the grain yield of rice treated with A1501 and A1513 increased by 8.5% and 10.3% respectively. And %Ndfa of rice shoot and grain estimated by 15 N-isotope dilution method was 9.00% and 11.5%, respectively, which was consistent with the increment of the total N(8.5% and 11.6%, respectively). The study indicated that ammonia resistant engineering strain A1513 had more stimulative effect on the growth of rice and grain yield than A1501

  15. Comparative analysis of drought resistance genes in Arabidopsis and rice

    NARCIS (Netherlands)

    Trijatmiko, K.R.

    2005-01-01

    Keywords: rice, Arabidopsis, drought, genetic mapping,microarray, transcription factor, AP2/ERF, SHINE, wax, stomata, comparative genetics, activation tagging, Ac/Ds, En/IThis thesis describes the use of genomics information and tools from Arabidopsis and

  16. Cooking and Eating Quality of Rice Yellow Mottle Virus Resistant ...

    African Journals Online (AJOL)

    Cooking and Eating Quantity of Rice Yellow Mottle 195 varieties often out compete introduced varieties on local markets; even though the former have lower yield potential. Breeding work incorporating grain quality was started in 1972 with the aim of developing varieties which combine high grain yield and grain quality ...

  17. Understanding rice plant resistance to the Brown Planthopper (Nilaparvata lugens): a proteomic approach.

    Science.gov (United States)

    Wei, Zhe; Hu, Wei; Lin, Qishan; Cheng, Xiaoyan; Tong, Mengjie; Zhu, Lili; Chen, Rongzhi; He, Guangcun

    2009-05-01

    Engineering and breeding resistant plant varieties are the most effective and environmentally friendly ways to control agricultural pests and improve crop performance. However, the mechanism of plant resistance to pests is poorly understood. Here we used a quantitative mass-spectrometry-based proteomic approach for comparative analysis of expression profiles of proteins in rice leaf sheaths in responses to infestation by the brown planthopper (Nilaparvata lugens Stål, BPH), which is a serious rice crop pest. Proteins involved in multiple pathways showed significant changes in expression in response to BPH feeding, including jasmonic acid synthesis proteins, oxidative stress response proteins, beta-glucanases, protein; kinases, clathrin protein, glycine cleavage system protein, photosynthesis proteins and aquaporins. The corresponding genes of eight important proteins were further analyzed by quantitative RT-PCR. Proteomic and transcript responses that were related to wounding, oxidative and pathogen stress overlapped considerably between BPH-resistant (carrying the resistance gene BPH15) and susceptible rice lines. In contrast, proteins and genes related to callose metabolism remained unchanged and glycine cleavage system protein was up-regulated in the BPH-resistant lines, indicating that they have an efficient and specific defense mechanism. Our results provide new information about the interaction between rice and the BPH.

  18. Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

    Science.gov (United States)

    Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

    2016-07-01

    Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

  19. Use of P-32 for determining varietal resistance of rice to brown planthopper (Nilaparvata lugens stal)

    Energy Technology Data Exchange (ETDEWEB)

    Kuswadi, A.N. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

    1981-07-01

    The resistance was assessed based on the feeding activities of the insect on 15-day old seedling of six test varieties namely TN 1, Asahan, Brantas, Citarum, Serayu and Mudgo. A level of 175 ..mu..Ci per seedling appeared to give sufficiently high absorption of radiophosphorus by the brown planthoppers. The level of radioactivity in the brown planthopper fed for 24 hours on labelled rice plants appeared to be correlated with the susceptibility of the rice plant to brown planthopper. The radioactivity in the honeydew of those hoppers was less correlated with the rice susceptibility. The promising resistance screening method using P-32 tracer is thus more reliable when the radioactivity is detected in the insect rather than in the honeydew.

  20. SP-LL-37, human antimicrobial peptide, enhances disease resistance in transgenic rice.

    Science.gov (United States)

    Lee, In Hye; Jung, Yu-Jin; Cho, Yong Gu; Nou, Ill Sup; Huq, Md Amdadul; Nogoy, Franz Marielle; Kang, Kwon-Kyoo

    2017-01-01

    Human LL-37 is a multifunctional antimicrobial peptide of cathelicidin family. It has been shown in recent studies that it can serve as a host's defense against influenza A virus. We now demonstrate in this study how signal peptide LL-37 (SP-LL-37) can be used in rice resistance against bacterial leaf blight and blast. We synthesized LL-37 peptide and subcloned in a recombinant pPZP vector with pGD1 as promoter. SP-LL-37 was introduced into rice plants by Agrobacterium mediated transformation. Stable expression of SP-LL-37 in transgenic rice plants was confirmed by RT-PCR and ELISA analyses. Subcellular localization of SP-LL-37-GFP fusion protein showed evidently in intercellular space. Our data on testing for resistance to bacterial leaf blight and blast revealed that the transgenic lines are highly resistant compared to its wildtype. Our results suggest that LL-37 can be further explored to improve wide-spectrum resistance to biotic stress in rice.

  1. Association between QTLs and morphological traits toward sheath blight resistance in rice (Oryza sativa L.)

    Science.gov (United States)

    Hossain, Md Kamal; Jena, Kshirod Kumar; Bhuiyan, Md Atiqur Rahman; Wickneswari, Ratnam

    2016-01-01

    Sheath blight is considered the most significant disease of rice and causes enormous yield losses over the world. Breeding for resistant varieties is the only viable option to combat the disease efficiently. Seventeen diverged rice genotypes along with 17 QTL-linked SSR markers were evaluated under greenhouse conditions. Pearson’s correlation showed only the flag leaf angle had a significant correlation with sheath blight resistance under greenhouse screening. Multivariate analysis based on UPGMA clustering and principal component analysis (PCA) indicated that the flag leaf angle, flag leaf length, and plant compactness were significantly associated with the following SSR marker alleles: RM209 (116,130), RM202 (176), RM224 (126), RM257 (156), RM426 (175), and RM6971 (196), which are linked to the SB QTLs: QRlh11, qSBR11-3, qSBR11-1, qSBR9-1, qShB3-2, and qSB-9. A Mantel test suggested a weak relationship between the observed phenotypes and allelic variation patterns, implying the independent nature of morphological and molecular variations. Teqing and Tetep were found to be the most resistant cultivars. IR65482-4-136-2-2, MR219-4, and MR264 showed improved resistance potentials. These results suggest that the morphological traits and QTLs which have been found to associate with sheath blight resistance are a good choice to enhance resistance through pyramiding either 2 QTLs or QTLs and traits in susceptible rice cultivars. PMID:27795687

  2. RFLP-facilitated investigation of the quantitative resistance of rice to brown planthopper ( Nilaparvata lugens).

    Science.gov (United States)

    Xu, X. F.; Mei, H. W.; Luo, L. J.; Cheng, X. N.; Li, Z. K.

    2002-02-01

    Quantitative trait loci (QTLs), conferring quantitative resistance to rice brown planthopper (BPH), were investigated using 160 F(11) recombinant inbred lines (RILs) from the Lemont/Teqing cross, a complete RFLP map, and replicated phenotyping of seedbox inoculation. The paternal indica parent, Teqing, was more-resistant to BPH than the maternal japonica parent, Lemont. The RILs showed transgressive segregation for resistance to BPH. Seven main-effect QTLs and many epistatic QTL pairs were identified and mapped on the 12 rice chromosomes. Collectively, the main-effect and epistatic QTLs accounted for over 70% of the total variation in damage scores. Teqing has the resistance allele at four main-effect QTLs, and the Lemont allele resulted in resistance at the other three. Of the main-effect QTLs identified, QBphr5b was mapped to the vicinity of gl1, a major gene controlling leaf and stem pubescence. The Teqing allele controlling leaf and stem pubescence was associated with resistance, while the Lemont allele for glabrous stem and leaves was associated with susceptibility, indicating that this gene may have contributed to resistance through antixenosis. Similar to the reported BPH resistance genes, the other six detected main-effect QTLs were all mapped to regions where major disease resistance genes locate, suggesting they might have contributed either to antibiosis or tolerance. Our results indicated that marker-aided pyramiding of major resistance genes and QTLs should provide effective and stable control over this devastating pest.

  3. Overexpression of rice serotonin N-acetyltransferase 1 in transgenic rice plants confers resistance to cadmium and senescence and increases grain yield.

    Science.gov (United States)

    Lee, Kyungjin; Back, Kyoungwhan

    2017-04-01

    While ectopic overexpression of serotonin N-acetyltransferase (SNAT) in plants has been accomplished using animal SNAT genes, ectopic overexpression of plant SNAT genes in plants has not been investigated. Because the plant SNAT protein differs from that of animals in its subcellular localization and enzyme kinetics, its ectopic overexpression in plants would be expected to give outcomes distinct from those observed from overexpression of animal SNAT genes in transgenic plants. Consistent with our expectations, we found that transgenic rice plants overexpressing rice (Oryza sativa) SNAT1 (OsSNAT1) did not show enhanced seedling growth like that observed in ovine SNAT-overexpressing transgenic rice plants, although both types of plants exhibited increased melatonin levels. OsSNAT1-overexpressing rice plants did show significant resistance to cadmium and senescence stresses relative to wild-type controls. In contrast to tomato, melatonin synthesis in rice seedlings was not induced by selenium and OsSNAT1 transgenic rice plants did not show tolerance to selenium. T 2 homozygous OsSNAT1 transgenic rice plants exhibited increased grain yield due to increased panicle number per plant under paddy field conditions. These benefits conferred by ectopic overexpression of OsSNAT1 had not been observed in transgenic rice plants overexpressing ovine SNAT, suggesting that plant SNAT functions differently from animal SNAT in plants. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Induced mutations to develop sources of resistance to rice blast, Pyricularia grisea Sacc

    International Nuclear Information System (INIS)

    Correa-Victoria, F.J.

    2001-01-01

    Rice blast caused by Pyricularia grisea is the most important disease limiting yields worldwide. The pathogen has many virulent forms or pathotypes, hence durable blast resistance is lacking. Studies on strategy to develop durable blast resistance based on defining the genetic structure of the population, using DNA-fingerprinting, and virulence diversity are described. This strategy is leading to the identification of resistance genes/sources against all isolates within a genetic family of the pathogen. Combinations of genes showing complementary resistance to different genetic families of the fungus exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. Identifying and combining resistance genes to which combinations of corresponding virulence genes are absent in the pathogen population should confer more durable resistance than that previously obtained. The use of induced mutations in the development of resistance was limited, since in most cases single gene changes were responsible for the induced resistance against all the pathogen population. The main objective here is to develop many mutants, each with a gene resistant to just one or a few families of the blast pathogen; and crossing them can accumulate the different resistance genes. A total of 201 Latin American commercial cultivars, including Cuban, Brazilian and Venezuelan were analyzed with different genetic families of the blast pathogen to identify potential sources of resistance to blast and identify complementary resistance sources. Characterization of the resistance of 37 mutants of the Colombian rice cultivar Oryzica 1 was conducted in collaboration with the INEA in Colombia. Results suggested that mutations for resistance to genetic families to which Oryzica 1 is susceptible were induced, although one

  5. Identification of molecular markers linked to rice bacterial blight resistance genes from Oryza meyeriana

    Directory of Open Access Journals (Sweden)

    Jing WANG,Chen CHENG,Yanru ZHOU,Yong YANG,Qiong MEI,Junmin LI,Ye CHENG,Chengqi YAN,Jianping CHEN

    2015-09-01

    Full Text Available Y73 is a progeny of asymmetric somatic hybridization between Oryza sativa cv. Dalixiang and the wild rice species Oryza meyeriana. Inoculation with a range of strains of Xanthomonas oryzae pv. oryzae showed that Y73 had inherited a high level of resistance to rice bacterial blight (BB from its wild parent. An F2 population of 7125 individuals was constructed from the cross between Y73 and a BB-susceptible cultivar IR24. After testing 615 SSR and STS markers covering the 12 rice chromosomes, 186 markers were selected that showed polymorphism between Y73 and IR24. Molecular markers linked to the BB resistance genes in Y73 were scanned using the F2 population and the polymorphic markers. The SSR marker RM128 on chromosome 1, the STS marker R03D159 on chromosome 3 and the STS marker R05D104 on chromosome 5 were found to be linked to the rice BB resistance genes in Y73.

  6. Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

    Science.gov (United States)

    Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

    2015-07-01

    Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

  7. Biochar amendment changes jasmonic acid levels in two rice varieties and alters their resistance to herbivory.

    Science.gov (United States)

    Waqas, Muhammad; Shahzad, Raheem; Hamayun, Muhammad; Asaf, Sajjad; Khan, Abdul Latif; Kang, Sang-Mo; Yun, Sopheap; Kim, Kyung-Min; Lee, In-Jung

    2018-01-01

    Biochar addition to soil not only sequesters carbon for the long-term but enhances agricultural productivity. Several well-known benefits arise from biochar amendment, including constant provision of nutrients, increased soil moisture retention, decreased soil bulk density, and sometimes the induction of systemic resistance against foliar and soil borne plant pathogens. However, no research has investigated the potential of biochar to increase resistance against herbivory. The white-backed plant hopper (WBPH) (Sogatella furcifera Horváth) is a serious agricultural pest that targets rice (Oryza sativa L.), a staple crop that feeds half of the world's human population. Therefore, we investigated the (1) optimization of biochar amendment levels for two rice varieties ('Cheongcheong' and 'Nagdong') and (2) subsequent effects of different biochar amendments on resistance and susceptibility of these two varieties to WBPH infestation. Initial screening results for the optimization level revealed that the application of biochar 10% (w/w) to the rooting media significantly improved plant physiological characteristics of both rice varieties. However, levels of biochar amendment, mainly 1, 2, 3, and 20%, resulted in negative effects on plant growth characteristics. Cheongcheong and Nagdong rice plants grown with the optimum biochar level showed contrasting reactions to WBPH infestation. Specifically, biochar application significantly increased plant growth characteristics of Nagdong when exposed to WBPH infestation and significantly decreased these characteristics in Cheongcheong. The amount of WBPH-induced damage to plants was significantly lower and higher in Nagdong and Cheongcheong, respectively, compared to that in the controls. Higher levels of jasmonic acid caused by the biochar priming effect could have accumulated in response to WBPH infestation, resulting in a maladaptive response to stress, negatively affecting growth and resistance to WBPH in Cheongcheong. This

  8. Morphological Evaluation of Shoots Regenerated from Hygromycin-Resistant Rice Callus (cv IACuba-28

    Directory of Open Access Journals (Sweden)

    Maylin Pérez Bernal

    2007-01-01

    Full Text Available An evaluation system based on the morphological characteristics of regenerated hygromycin-resistant rice callus shoots was established for correlating such characteristics with shoot viability on hygromycin. Embryogenic rice calli were transformed by Agrobacterium tumefaciens (EHA105/ pCAMBIA1300, containing the hygromycin-phosphotransferase gene as selection marker. After two weeks on selection medium, hygromycin-resistant calli were transferred to regeneration medium. Regenerated shoots were extracted every 5 days (over a 30-day period and classified into three classes according to their morphological structure: class I: vigorous shoot having typical bipolar structure; class II: shoot having small root compared to apical length, or shoot without roots; class III: shoots having an abnormal appearance, such as malformed leaves or albinism. Individualised shoots were transferred to MS medium containing hygromycin for evaluating their resistance to antibiotics. A relationship was observed between regenerated shoots’ morphological characteristics and the percentage of shoots’ viability on hygromycin. Class I prevailed at early shoot extraction and was the most resistant to hygromycin. Drastic class I reduction was found with later shoot extraction, whilst classes II and III became increased. Likewise, shoot viability became radically reduced on MS medium containing hygromycin. This result might be applied for improving efficiency regarding obtaining transgenic rice plants, taking into account the best time for obtaining high percentages of hygromycin-resistant shoots having the best morphological characteristics.

  9. Novel QTLs affecting rice kernel fissure resistance discovered in the cultivar ‘Saber’ augment those from ‘Cybonnet’

    Science.gov (United States)

    Kernel fissures in rice (Oryza sativa L.) caused by pre- or post-harvest stresses are the leading cause of breakage among milled rice. Such breakage causes economic losses for producers, millers, and marketers. Five QTLs for kernel fissure resistance (FR) were identified among a set of 275 RILs de...

  10. Correlation of pasting behaviors with total phenolic compounds and starch digestibility of indigenous pigmented rice grown in upper Northern Thailand

    Directory of Open Access Journals (Sweden)

    Jirapa Ponjanta

    2016-03-01

    Full Text Available Background: Thailand has one of the most important rice genetic resources with white, light brown, brown, red, and purple rice bran colors. The latter believed to have potential for health benefits due to their phenolic content. Recently researchers have indicated that starch digestive enzymes, including salivary and pancreatic α-amylases and α-glucosidases, can be inhibited by phenolic compounds. Although pasting properties of rice flour are key determinants of quality significantly impacting the final product texture, there is no in-depth study on their correlation with phenolic compound and starch digestibility. Methods: Rice flour from twelve varieties, three from each of five bran colors (white, brown, red, and purple, were evaluated for pasting properties (RVA-3D, total phenolic compounds, amylose content, resistant starch and estimated glycemic index. Simple correlation coefficients were calculated for the relationships between pasting properties (final viscosity, breakdown, setback and pasting temperature and total phenolic compounds, resistant starch and estimated glycemic index. Results: Within each rice variety, red and purple pigmented flours had higher total phenolic compounds (TPC and more resistant starch than that of white flours. The TPC and resistant starch content of the flours ranged between 7.83- 47.3 mg/L and 2.44–10.50% respectively, and producing 60-80 of estimated glycemic index. Viscosity behavior showed that pigmented with low amylose rice had lower viscosity temperature than that of pigmented with high amylose rice flour, but higher in peak viscosity. Correlation coefficients of pasting temperature, final viscosity, break down and setback with TCP was observed to be inversely related to glycemic index. However, it was positively correlated to the resistant starch and amylose content. Conclusions: Pigmented rice flour is a better source of TPC and resistant starch which in turn provides low glycemic index. This

  11. Mechanisms of callose deposition in rice regulated by exogenous abscisic acid and its involvement in rice resistance to Nilaparvata lugens Stål (Hemiptera: Delphacidae).

    Science.gov (United States)

    Liu, Jinglan; Du, Haitao; Ding, Xu; Zhou, Yaodong; Xie, Pengfei; Wu, Jincai

    2017-12-01

    Callose is a plant cell wall polysaccharide controlled by β-1,3-glucanase and synthase. Abscisic acid (ABA) is an important plant hormone. Exogenous ABA promotes rice resistance to pests. Whether exogenous ABA could reduce the decline in rice yield after brown planthopper (Nilaparvata lugens Stål; BPH) feeding is an important question, however, the mechanisms behind rice resistance induced by ABA remain obscure. Electronic penetration graph (EPG) recording indicated a significant increase in rice resistance to BPH, and the number of BPH eggs decreased significantly upon application of exogenous ABA. As the concentration of ABA increased, the reduction in rice yield decreased significantly after BPH feeding. Further studies showed that β-1,3-glucanase activity was significantly lower, but synthase activity was higher after ABA treatment than in controls. Our results demonstrated that exogenous ABA suppressed β-1,3-glucanase and induced synthase activity, and promoted callose deposition. This is an important defense mechanism that prevents BPH from ingesting phloem sap. These studies provide support for an insect-resistance mechanism after ABA treatment and provide a reference for the integrated management of other piercing-sucking pests. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. GENETICS OF BROWN PLANTHOPPER (NILAPARVATA LUGENS STAL.) RESISTANCE IN ELITE DONORS OF RICE (ORYZA SATIVA L.)

    OpenAIRE

    B BALAKRISHNA; P V SATAYANARAYANA

    2013-01-01

    The inheritance of resistance to the brown planthopper (BPH) in four BPH resistant donors of rice i. e., Sinna Sivappu, Sudu Hondarawala, PTB 33 and BM 71 was studied both in field and greenhouse conditions. The F2 population of crosses involving donors Sinna Sivappu, Sudu Hondarawala and PTB 33 fit into the ratio of 13:3 indicating the resistance to BPH was controlled by two genes i. e., one dominant and one recessive gene segregating independent to each other. The F2 populat...

  13. The genetic variance of resistance in M3 lines of rice against leaf blight disease

    International Nuclear Information System (INIS)

    Mugiono

    1979-01-01

    Seeds of Pelita I/1 rice variety were irradiated with 20, 30, 40 and 50 krad of gamma rays from a 60 Co source. Plants of M 3 lines were inoculated with bacterial leaf blight, Xanthomonas oryzae (Uzeda and Ishiyama) Downson, using clipping method. The coefficient of genetic variability of resistance against leaf blight disease increased with increasing dose. Highly significant difference in the genetic variance of resistance were found between the treated samples and the control. Dose of 20 krad gave good probability for selection of plants resistant against leaf blight disease. (author)

  14. Development of the variety for resistance against bacterial leaf-blight in rice with thermal neutrons

    International Nuclear Information System (INIS)

    Nakai, Hirokazu

    1990-01-01

    In search for the development of genes for resistance against bacterial leaf-blight in rice, thermal neutrons generated from the Research Reactor at the Kyoto University have been applied to the breeding. In this paper, the developmental outcome is described, and a potential application of thermal neutrons for breeding the variety of resistance against bacterial leaf-blight in rice is reviewed. When thermal neutrons were delivered to the rice, the ratio of absorbed doses by B-10, which is contained in a small quantity in the plant, was found to be larger than expected. This implies characteristic effects of thermal neutrons on the plant. When boric acid was incorporated into the plant before irradiation, the effect of thermal neutrons per irradiation time was considered to become great. The frequency of mutations for resistance was significantly higher by thermal neutron, as compared with that induced by other mutagens, such as gamma radiation, ethylene-imine, ethyl-methane-sulfonate, and nitroso-methyl-urea. Genetic analysis of mutants for resistance revealed recessive genes and polygenes. Finally, the application of thermal neutrons and other radiations would contribute greatly to a resolution of serious pollution problems in global food and environment. (N.K.)

  15. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

  16. New target for rice lodging resistance and its effect in a typhoon.

    Science.gov (United States)

    Ishimaru, Ken; Togawa, Eiji; Ookawa, Taiichro; Kashiwagi, Takayuki; Madoka, Yuka; Hirotsu, Naoki

    2008-02-01

    We demonstrated the new target for lodging resistance in rice (Oryza sativa L.) by the analysis of physiological function of a locus for lodging resistance in a typhoon (lrt5) with the near isogenic line under rice "Koshihikari" genetic background (tentatively named S1). The higher lodging resistance of S1 was observed during a typhoon in September 2004 (28 days after heading), when most other plants in "Koshihikari" became lodged. Visual observations showed that bending of the upper stems triggered lodging during the typhoon; the upper stem of "Koshihikari" buckled completely, whereas that of S1 remained straight. In addition to the strong rain and winds during the typhoon, the weight of the buckled upper plant parts increased the pressure on adjacent plants and caused a domino effect in "Koshihikari". Young's modulus, an indicator of the rigidity of the culm, was significantly higher in S1 than in "Koshihikari". In the upper culm, the starch content in S1 was 4.8 times the value in "Koshihikari", and senescence was delayed in the upper leaves of S1. These results suggest that the rigidity of the upper culm by the higher starch content (as a result of delayed senescence in the upper leaves) may be responsible for the higher lodging resistance during a typhoon in rice.

  17. Evaluation of rice mutant lines for resistance to brown planthopper, nilaparvata lugens stall

    International Nuclear Information System (INIS)

    Mugiono

    1985-01-01

    The most important and common insect in rice cultivation in South East Asia is brown planthopper, nilaparvata lugens stall. Seven rice mutant lines produced by the National Atomic Energy Agency, Indonesia, were tested at IRRI, the Philippines for resistance to brown planthopper. Those mutant lines were Atomita 1, 627/10-3/PsJ, Atomita 2 and 627/4-E/PsJ originated from Pelita 1/1 which was irradiated with 0.2 kGy of gamma rays and A227/2/PsJ, A227/3/PsJ and A227/5/PsJ, originated from early maturing mutant A23/PsJ/72K from irradiated Pelita 1/1 which was irradiated with 0.1 kGy of gamma rays. Evaluation of resistance was carried out by seedling bulk screening, honeydew excretion, survival and population build up tests by using brown planthopper biotype 1, 2 and 3. Results of these tests showed that the seven tested mutant lines were resistant to biotype 1 but susceptible to biotype 2. Reaction to biotype 3 showed that six mutant lines tested were moderately resistant and only one mutant of 627/4-E/PsJ was susceptible. Reactions of the mutant lines to biotype 1, 2 and 3 were different from the resistant varieties, Mudgo or ASD-7. This indicated that mutant lines might have gene(s) for resistance which differed from those of resistant varieties. The results showed that resistance to brown planthopper is possible to be introduced in Indonesian rice varieties by means of mutations. (author)

  18. Molecular mapping and genetic analysis of a rice brown planthopper (Nilaparvata lugens Stål) resistance gene.

    Science.gov (United States)

    Yang, Haiyuan; Ren, Xiang; Weng, Qingmei; Zhu, Lili; He, Guangcun

    2002-01-01

    The brown planthopper (BPH), Nilaparvata lugens Stål, is a serious insect pest of rice (Oryza saliva L.). We have determined the chromosomal location of a BPH resistance gene in rice using SSR and RFLP techniques. A rice line 'B14', derived from the wild rice Oryza latifolia, showed high resistance to BPH. For tagging the resistance gene in 'B14X', an F2 population and a recombinant inbred (RI) population from a cross between Taichung Native 1 and 'B14' were developed and evaluated for BPH resistance. The results showed that a single dominant gene controlled the resistance of 'B14' to BPH. Bulked segregant SSR analysis was employed for identification of DNA markers linked to the resistance gene. From the survey of 302 SSR primer pairs, three SSR (RM335, RM261, RM185) markers linked to the resistance gene were identified. The closest SSR marker RM261 was linked to the resistance gene at a distance of 1.8 cM. Regions surrounding the resistance gene and the SSR markers were examined with additional RFLP markers on chromosome 4 to define the location of the resistance gene. Linkage of RFLP markers C820, R288, C946 with the resistance gene further confirmed its location on the short arm of chromosome 4. Closely linked DNA markers will facilitate selection for resistant lines in breeding programs and provide the basis for map-based cloning of this resistance gene.

  19. Overexpression of Phosphomimic Mutated OsWRKY53 Leads to Enhanced Blast Resistance in Rice

    Science.gov (United States)

    Ogawa, Satoshi; Masuda, Yuka; Shimizu, Takafumi; Kishi-Kaboshi, Mitsuko; Takahashi, Akira; Nishizawa, Yoko; Minami, Eiichi; Nojiri, Hideaki; Yamane, Hisakazu; Okada, Kazunori

    2014-01-01

    WRKY transcription factors and mitogen-activated protein kinase (MAPK) cascades have been shown to play pivotal roles in the regulation of plant defense responses. We previously reported that OsWRKY53-overexpressing rice plants showed enhanced resistance to the rice blast fungus. In this study, we identified OsWRKY53 as a substrate of OsMPK3/OsMPK6, components of a fungal PAMP-responsive MAPK cascade in rice, and analyzed the effect of OsWRKY53 phosphorylation on the regulation of basal defense responses to a virulence race of rice blast fungus Magnaporthe oryzae strain Ina86-137. An in vitro phosphorylation assay revealed that the OsMPK3/OsMPK6 activated by OsMKK4 phosphorylated OsWRKY53 recombinant protein at its multiple clustered serine-proline residues (SP cluster). When OsWRKY53 was coexpressed with a constitutively active mutant of OsMKK4 in a transient reporter gene assay, the enhanced transactivation activity of OsWRKY53 was found to be dependent on phosphorylation of the SP cluster. Transgenic rice plants overexpressing a phospho-mimic mutant of OsWRKY53 (OsWRKY53SD) showed further-enhanced disease resistance to the blast fungus compared to native OsWRKY53-overexpressing rice plants, and a substantial number of defense-related genes, including pathogenesis-related protein genes, were more upregulated in the OsWRKY53SD-overexpressing plants compared to the OsWRKY53-overexpressing plants. These results strongly suggest that the OsMKK4-OsMPK3/OsMPK6 cascade regulates transactivation activity of OsWRKY53, and overexpression of the phospho-mimic mutant of OsWRKY53 results in a major change to the rice transcriptome at steady state that leads to activation of a defense response against the blast fungus in rice plants. PMID:24892523

  20. Overexpression of phosphomimic mutated OsWRKY53 leads to enhanced blast resistance in rice.

    Directory of Open Access Journals (Sweden)

    Tetsuya Chujo

    Full Text Available WRKY transcription factors and mitogen-activated protein kinase (MAPK cascades have been shown to play pivotal roles in the regulation of plant defense responses. We previously reported that OsWRKY53-overexpressing rice plants showed enhanced resistance to the rice blast fungus. In this study, we identified OsWRKY53 as a substrate of OsMPK3/OsMPK6, components of a fungal PAMP-responsive MAPK cascade in rice, and analyzed the effect of OsWRKY53 phosphorylation on the regulation of basal defense responses to a virulence race of rice blast fungus Magnaporthe oryzae strain Ina86-137. An in vitro phosphorylation assay revealed that the OsMPK3/OsMPK6 activated by OsMKK4 phosphorylated OsWRKY53 recombinant protein at its multiple clustered serine-proline residues (SP cluster. When OsWRKY53 was coexpressed with a constitutively active mutant of OsMKK4 in a transient reporter gene assay, the enhanced transactivation activity of OsWRKY53 was found to be dependent on phosphorylation of the SP cluster. Transgenic rice plants overexpressing a phospho-mimic mutant of OsWRKY53 (OsWRKY53SD showed further-enhanced disease resistance to the blast fungus compared to native OsWRKY53-overexpressing rice plants, and a substantial number of defense-related genes, including pathogenesis-related protein genes, were more upregulated in the OsWRKY53SD-overexpressing plants compared to the OsWRKY53-overexpressing plants. These results strongly suggest that the OsMKK4-OsMPK3/OsMPK6 cascade regulates transactivation activity of OsWRKY53, and overexpression of the phospho-mimic mutant of OsWRKY53 results in a major change to the rice transcriptome at steady state that leads to activation of a defense response against the blast fungus in rice plants.

  1. Comparative transcriptome profiling of resistant and susceptible rice genotypes in response to the seedborne pathogen Fusarium fujikuroi.

    Science.gov (United States)

    Matić, Slavica; Bagnaresi, Paolo; Biselli, Chiara; Orru', Luigi; Amaral Carneiro, Greice; Siciliano, Ilenia; Valé, Giampiero; Gullino, Maria Lodovica; Spadaro, Davide

    2016-08-11

    Fusarium fujikuroi is the causal agent of bakanae, the most significant seed-borne disease of rice. Molecular mechanisms regulating defence responses of rice towards this fungus are not yet fully known. To identify transcriptional mechanisms underpinning rice resistance, a RNA-seq comparative transcriptome profiling was conducted on infected seedlings of selected rice genotypes at one and three weeks post germination (wpg). Twelve rice genotypes were screened against bakanae disease leading to the identification of Selenio and Dorella as the most resistant and susceptible cultivars, respectively. Transcriptional changes were more appreciable at 3 wpg, suggesting that this infection stage is essential to study the resistance mechanisms: 3,119 DEGs were found in Selenio and 5,095 in Dorella. PR1, germin-like proteins, glycoside hydrolases, MAP kinases, and WRKY transcriptional factors were up-regulated in the resistant genotype upon infection with F. fujikuroi. Up-regulation of chitinases and down-regulation of MAP kinases and WRKY transcriptional factors were observed in the susceptible genotype. Gene ontology (GO) enrichment analyses detected in Selenio GO terms specific to response to F. fujikuroi: 'response to chitin', 'jasmonic acid biosynthetic process', and 'plant-type hypersensitive response', while Dorella activated different mechanisms, such as 'response to salicylic acid stimulus' and 'gibberellin metabolic process', which was in agreement with the production of gibberellin A3 in Dorella plants. RNA-seq profiling was performed for the first time to analyse response of rice to F. fujikuroi infection. Our findings allowed the identification of genes activated in one- and three- week-old rice seedlings of two genotypes infected with F. fujikuroi. Furthermore, we found the pathways involved in bakanae resistance, such as response to chitin, JA-dependent signalling and hypersensitive response. Collectively, this provides important information to elucidate the

  2. The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Thomas, Nicholas C; Oksenberg, Nir; Liu, Furong; Caddell, Daniel; Nalyvayko, Alina; Nguyen, Yen; Schwessinger, Benjamin; Ronald, Pamela C

    2018-01-01

    Rice ( Oryza sativa ) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo . To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo . We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo . These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo .

  3. Characterization of a disease susceptibility locus for exploring an efficient way to improve rice resistance against bacterial blight

    Institute of Scientific and Technical Information of China (English)

    Qi Cheng; Weihua Mao; Wenya Xie; Qinsong Liu; Jianbo Cao; Meng Yuan; Qinglu Zhang; Xianghua Li; Shiping Wang

    2017-01-01

    Bacterial blight caused by Xanthomonas oryzae pv.oryzae (Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance (MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.

  4. Evaluating Sheath Blight Resistance in Rice Using Detached Tiller and Field Screening Method

    Directory of Open Access Journals (Sweden)

    Bedanand Chaudhary

    2015-12-01

    Full Text Available In present study physical resistance test on 12 rice varieties against sheath blight (ShB caused by Rhizoctonia solani was examined. A detached tiller test was used to measure components of ShB physiological resistance at Regional Agricultural Research Station (RARS, Tarahara, Nepal. The varieties were evaluated in a randomized complete block design (RCBD with 3 replications in year 2010-12. A sclerotium was inserted below the leaf collar of individual tillers maintained in tubes filled with water. Only the 56-day old susceptible plants were inoculated. After 7 days of inoculation, number of lesions, dead leaves, vertical sheath colonization and disease severity were measured. In 2011, field experiments were conducted with three replications to address morphological resistance in 28 rice genotypes. Disease incidence was recorded on 14, 21 and 28 days after inoculation. The number of dead leaves differed only numerically while disease variables significantly (P=0.004 varied among varieties. The other variables were highly correlated with each other. Cluster analysis of variables formed three varietal groups; Sabitri with lowest, and Jasmine-85 and Betichikon having highest values. Rice genotypes differed significantly (P=0.05 for disease incidence and area Under Disease Progress Curve (AUDPC. Tetep and IAC-165 had the lowest and highest terminal disease incidences and AUDPC, respectively. Sabitri, MTU-1010 and IR-26 recorded lower AUDPC values. Hence, Tetep and Sabitri could be used as donors in hybridization and their plant morphology could be considered as selection guide for improving ShB resistance in rice.

  5. Transcriptional Network Analysis Reveals Drought Resistance Mechanisms of AP2/ERF Transgenic Rice

    Directory of Open Access Journals (Sweden)

    Hongryul Ahn

    2017-06-01

    Full Text Available This study was designed to investigate at the molecular level how a transgenic version of rice “Nipponbare” obtained a drought-resistant phenotype. Using multi-omics sequencing data, we compared wild-type rice (WT and a transgenic version (erf71 that had obtained a drought-resistant phenotype by overexpressing OsERF71, a member of the AP2/ERF transcription factor (TF family. A comprehensive bioinformatics analysis pipeline, including TF networks and a cascade tree, was developed for the analysis of multi-omics data. The results of the analysis showed that the presence of OsERF71 at the source of the network controlled global gene expression levels in a specific manner to make erf71 survive longer than WT. Our analysis of the time-series transcriptome data suggests that erf71 diverted more energy to survival-critical mechanisms related to translation, oxidative response, and DNA replication, while further suppressing energy-consuming mechanisms, such as photosynthesis. To support this hypothesis further, we measured the net photosynthesis level under physiological conditions, which confirmed the further suppression of photosynthesis in erf71. In summary, our work presents a comprehensive snapshot of transcriptional modification in transgenic rice and shows how this induced the plants to acquire a drought-resistant phenotype.

  6. Mutational rectification for resistance to diseases in rice and bread wheat

    International Nuclear Information System (INIS)

    Chakrabarti, S.N.; Kar, G.N.; Sen, B.

    1976-01-01

    The mutation breeding programme with a view to rectify the defects of severe susceptibility to important diseases of a few varieties of rice and bread wheat was undertaken using different mutagenic treatments with radiation (X-rays and gamma rays), chemical mutagens (EMS, NMU, NEU) and combination of radiation and chemical mutagens (gamma rays + EMS). In rice two mutant strains have shown moderate resistance to helminthosporiose, one strain to both helminthosporiose and blast and five strains resistant to bacterial leaf blight under artificial epiphytotic conditions. In bread wheat, out of large M 2 population, derived from different mutagenic treatments, the frequencies of appearance of mutants resistant to rust diseases were observed to be 0.03 percent in H.D. 1944 from 0.2 percent EMS treatment, 0.06 percent in H.D. 1999 from 0.01 percent NEU treatment and 0.07 percent in Kalyan Sona from combined treatment with 20 krad gamma rays and 0.4 percent EMS. The mutants bred true for resistance upto M 6 generations. A few of the mutants, resistant to different diseases in rjce and bread wheat, proved to be very promising in yield. An early (earlier to Kalyan Sona by 25 days) mutant, derived from Kalyan Sona, topped in yield out of 49 varieties tested in 1974l75 in Delhi and Pusa. The Kalyan Sona early tested in 1974-75 in Delhi and Pusa. The Kalyan Sona early mutant is having resistance to yellow and brown rusts. (author)

  7. Expression Analysis of Genes Related to Rice Resistance Against Brown Planthopper, Nilaparvata lugens

    Directory of Open Access Journals (Sweden)

    Panatda Jannoey

    2017-05-01

    Full Text Available Brown planthopper (BPH is an insect species that feeds on the vascular system of rice plants. To examine the defence mechanism of rice plants against BPH, the pathogenesis-related genes (PR1a, PR2, PR3, PR4, PR6, PR9, PR10a, PR13, PR15 and PRpha, signaling molecule synthesis genes (AOS, AXR, ACO and LOX, antioxidant-related genes (CAT, TRX, GST and SOD and lignin biosynthesis-related genes (CHS, CHI and C4H were investigated in a resistant rice variety. AOS, PR6, PR9 and PR15 genes showed significantly increased relative expression levels at 24.38-, 19.17-, 14.71-, and 12.74-fold compared to the control. Moderate increased relative expression levels of lignin biosynthesis-related gene (C4H, pathogenesis-related genes (PR4, PR10a and PRpha, and antioxidant-related gene (GST were found, while CHI, LOX, SOD, TRX1 and AXR showed decreased relative expression levels. It was thus clearly shown that wound-induced response genes were activated in rice plants after BPH attacks through AOS activation. Jasmonic acid signaling molecule may activate PR6, PR15, GST and CAT subsequently increasing their expression for H2O2 detoxification. PR6 were expressed at the highest relative level among the PR genes. These genes therefore have also a considerable synergistic role with the other genes against BPH by interfered their digestion tract system.

  8. Identification of blast resistance expression in rice genotypes using ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... for pyramid resistance genes because the presence of one major gene ... of inoculums. Standard agronomic management practices were .... CSR-27. 80.00 ± 4.46. 85.00 ± 4.62. 2062.50 ± 192.25. 2098.81 ± 193.18. SVT-10.

  9. In-vitro vs in-vivo Inoculation: Screening for Resistance of Australian Rice Genotypes Against Blast Fungus

    Directory of Open Access Journals (Sweden)

    Vineela Challagulla

    2015-05-01

    Full Text Available To assist with rapid screening for rice blast resistance as a precursor in a breeding program, the susceptibility to rice blast of 13 rice genotypes from Australia was evaluated in May to June 2013 using three distinct inoculation methods (spot, filter paper and standard methods at seedling, vegetative and reproductive stages. The results revealed that the spot and filter paper inoculation methods were successful in discerning susceptibility to the rice blast disease (P ≤ 0.05. Disease susceptibility declined significantly from the vegetative to reproductive stages. The standard method was conducted at three different stages for pot plants grown inside the mist house. However, low temperatures did not produce disease symptoms except in a few genotypes. Among the 13 rice genotypes screened, AAT9 expressed a highly resistant response, and AAT4, AAT6, AAT10, AAT11, AAT13, AAT17 and AAT18 expressed resistance at various stages. The results will be useful for selecting elite genotypes for disease tolerance where rice blast is prevalent. In addition, the resistant genotypes can serve as a gene pool used in breeding programmes to develop new resistant genotypes.

  10. Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.

    Science.gov (United States)

    Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

    2013-10-01

    Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.

  11. Evolving ideas about genetics underlying insect virulence to plant resistance in rice-brown planthopper interactions.

    Science.gov (United States)

    Kobayashi, Tetsuya

    2016-01-01

    Many plant-parasite interactions that include major plant resistance genes have subsequently been shown to exhibit features of gene-for-gene interactions between plant Resistance genes and parasite Avirulence genes. The brown planthopper (BPH) Nilaparvata lugens is an important pest of rice (Oryza sativa). Historically, major Resistance genes have played an important role in agriculture. As is common in gene-for-gene interactions, evolution of BPH virulence compromises the effectiveness of singly-deployed resistance genes. It is therefore surprising that laboratory studies of BPH have supported the conclusion that virulence is conferred by changes in many genes rather than a change in a single gene, as is proposed by the gene-for-gene model. Here we review the behaviour, physiology and genetics of the BPH in the context of host plant resistance. A problem for genetic understanding has been the use of various insect populations that differ in frequencies of virulent genotypes. We show that the previously proposed polygenic inheritance of BPH virulence can be explained by the heterogeneity of parental populations. Genetic mapping of Avirulence genes indicates that virulence is a monogenic trait. These evolving concepts, which have brought the gene-for-gene model back into the picture, are accelerating our understanding of rice-BPH interactions at the molecular level. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Transgenic rice plants expressing a fused protein of Cry1Ab/Vip3H has resistance to rice stem borers under laboratory and field conditions.

    Science.gov (United States)

    Chen, Yang; Tian, Jun-Ce; Shen, Zhi-Chen; Peng, Yu-Fa; Hu, Cui; Guo, Yu-Yuan; Ye, Gong-Yin

    2010-08-01

    Six transgenic rice, Oryza sativa L., lines (G6H1, G6H2, G6H3, G6H4, G6H5, and G6H6) expressing a fused Cry1Ab/Vip3H protein, were evaluated for resistance against the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and the stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) in the laboratory and field. The bioassay results indicated that the mortality of Asiatic rice borer and S. inferens neonate larvae on six transgenic lines from seedling to filling stage was up to 100% at 168 h after infestation. The cumulative feeding area by Asiatic rice borer neonate larvae on all transgenic lines was significantly reduced compared with the untransformed parental 'Xiushui 110' rice. A 2-yr field evaluation showed that damage during the vegetative stage (deadheart) or during the reproductive stage (whitehead) caused by Asiatic rice borer and S. inferens for transgenic lines was much lower than the control. For three lines (G6H1, G6H2, and G6H6), no damage was found during the entire growing period. Estimation of fused Cry1Ab/Vip3H protein concentrations using PathoScreen kit for Bt-Cry1Ab/1Ac protein indicated that the expression levels of Cry1Ab protein both in main stems (within the average range of 0.006-0.073% of total soluble protein) and their flag leaves (within the average range of 0.001-0.038% of total soluble protein) were significantly different among six transgenic lines at different developmental stages. Both laboratory and field researches suggested that the transgenic rice lines have considerable potential for protecting rice from attack by both stem borers.

  13. Expressional and Biochemical Characterization of Rice Disease Resistance Gene Xa3/Xa26 Family

    Institute of Scientific and Technical Information of China (English)

    Songjie Xu; Yinglong Cao; Xianghua Li; Shiping Wang

    2007-01-01

    The rice (Oryza sativa L.) Xa3/Xa26 gene, conferring race-specific resistance to bacterial blight disease and encoding a leucine-rich repeat (LRR) receptor kinase-like protein, belongs to a multigene family consisting of tandem clustered homologous genes, colocalizing with several uncharacterized genes for resistance to bacterial blight or fungal blast. To provide more information on the expressional and biochemical characteristics of the Xa3/Xa26 family, we analyzed the family members. Four Xa3/Xa26 family members in the indica rice variety Teqing, which carries a bacterial blight resistance gene with a chromosomal location tightly linked to Xa3/Xa26, and five Xa3/Xa26 family members in the japonica rice variety Nipponbare, which carries at least one uncharacterized blast resistance gene, were constitutively expressed in leaf tissue. The result suggests that some of the family members may be candidates of these uncharacterized resistance genes. At least five putative N-glycosylation sites in the LRR domain of XA3/XA26 protein are not glycosylated. The XA3/XA26 and its family members MRKa and MRKc all possess the consensus sequences of paired cysteines, which putatively function in dimerization of the receptor proteins for signal transduction, immediately before the first LRR and immediately after the last LRR. However, no homo-dimer between the XA3/XA26 molecules or hetero-dimer between XA3/XA26 and MRKa or MRKc were formed, indicating that XA3/XA26 protein might function either as a monomer or a hetero-dimer formed with other protein outside of the XA3/XA26 family. These results provide valuable information for further extensive investigation into this multiple protein family.

  14. Isolation and Manipulation of Quantitative Tra it Loci for DIsease Resistance in Rice Using a Candid ate Gene Approach

    Institute of Scientific and Technical Information of China (English)

    Ke-Ming Hu; De-Yun Qiu; Xiang-Ling Shen; Xiang-Hua Li; Shi-Ping Wang

    2008-01-01

    Bacterial blight caused by Xanthomonas oryzae pv.oryzae and fungal blast caused by Magnaporthe grisea result in heavy production losses in rice,a main staple food for approximately 50%of the world's population.Application of host resistance to these pathogens iS the most economical and environment-friendly approach to solve this problem.Quantitative trait loci(QTLs)controlling quantitative resistance are valuable sources for broad.spectrum and durable disease resistance.Although large numbers of QTLs for bacteriaI blight and blast resistance have been identified.these sources have not been used effectively in rice improvement because of the complex genetic controI of quantitative resistance and because the genes underlying resistance QTLs are unknown.To isolate disease resistance QTLs,we established a candidate gene strategy that integrates linkage map,expression profile,and functionaI complementation analyses.This strategy has proven to be applicable for identifying the genes underlying minor resistance QTLs in rice-Xoo and rice-M grisea systems and it may also help to shed light on disease resistance QTLs of other cereals.Our results also suggest that a single minor QTL can be used in rice improvement by modulating the expression of the gene underlying the QTL.Pyramiding two or three minor QTL genes,whose expression can be managed and that function in different defense signaI transduction pathways,may allow the breeding of rice cultivars that are highly resistant to bacteriaI blight and blast.

  15. Influence of fertilization on the capability of rice resistance to diseases

    Science.gov (United States)

    Hu, Xue-Feng; Chang, Yue-Ya; Jiang, Ying; Yan, Xiao-Juan; Luo, Fan

    2013-04-01

    Organic cultivation of rice requires no use of any agricultural chemicals during the entire period of growth, and so the rice's self-prevention of diseases and pests is vitally important. A field experiment was carried out to study the possible influence of different fertilization on the capability of rice resistance to diseases and pests. A rice variety used for this experiment is Jia-He 218. Four treatments (A, B, C and D) were designed: A is a control, without using any fertilizers; B, after manuring of green azolla, 0.67 kg/m2; C, after manuring of rapeseed cake, 0.30 kg/m2; D, after fertilizing of ammonium bicarbonate, 0.025 kg/m2, and urea, 0.025 kg/m2. The experiment plot is 66.7 m2, with three replicates. The results indicated that the fertilization patterns significantly influence the growth of rice seedlings: The heights by A, B, C and D are 37 cm, 40 cm , 42 cm and 45 cm on average, respectively; the spike numbers, 45, 65, 73 and 75, respectively; chlorophyll contents in leaves, 1.84 mg/g, 2.42 mg/g, 3.02 mg/g and 3.97 mg/g, respectively. The rice with the different fertilization also varies in nutrient concentration in leaves: NH4-N concentration in leaves by A, B, C and D is 47.5 mg/kg, 61.1 mg/kg, 74.7 mg/kg and 135.8 mg/kg on average, respectively; NO3-N in leaves, 138.9 mg/kg, 185.2 mg/kg, 154.3 mg/kg and 293.2 mg/kg, respectively. The fertilization patterns, moreover, show a significant influence on the incidence of diseases and pests to rice seedlings: The incidence of rice cnaphalocrocis medinalis by A, B, C and D is 1.33 %, 1.50 %, 1.75 % and 89.0 % on average, respectively; that of bacterial leaf blight, 0, 1.25 %, 1.75 % and 85.0 %, respectively; number of rice planthopper in each plant, 20, 21, 21 and 30, respectively. As a result, the yield of rice grain by A, B, C and D is 4540 kg/ha, 4606 kg/ha, 4503 kg/ha and 4092 kg/ha on average, respectively. In conclusion, the rice seedlings treated with chemical fertilizers grow large and tender

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

    International Nuclear Information System (INIS)

    Nakai, H.

    1990-01-01

    Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M 3 or M 4 lines derived from selected resistant M 2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

  17. Breeding for earliness, high yield and disease resistance in rice by means of induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    Haq, M S; Ali, S M; Maniruzzaman, A F.M.; Mansur, A; Islam, R [Atomic Energy Centre, Dacca (Pakistan)

    1970-03-01

    Ten varieties of Boro, Aus and Aman rice were treated with 30 kR of gamma rays from the 500-Ci {sup 60}Co source of the Atomic Energy Centre of Dacca. In addition, two rice varieties were treated with EMS and dES. To suppress tillering, the seeds were sown late and at a high seed rate. 300 normal-looking fertile M{sub 1} plants from each variety were harvested at random. The M{sub 2} progenies were sown on a plant-to-row basis to select for high yield, earliness, blast resistance and response to large doses of nitrogen fertilizer. Characters like plant height, number of tillers, fertile tillers, length of panicle and time from sowing to maturity were checked. As the results showed great variability in the mutagen-treated material the chances for successful selection are promising. (author)

  18. Screening for rice mutant of resistance to piricularia oryzae by irradiation and in vitro technique

    International Nuclear Information System (INIS)

    Wang Cailian; Xu Gang; Chen Qiufang; Jin Wei

    2001-01-01

    The ability of callus formation and green plant regeneration was very different for different rice types and varieties in mature embryo. LS-5 was optimum medium for mature embryo. Increase in plant regeneration capacity was found with 100, 150 Gy gamma rays. The differentiation and regeneration of green plants were obviously improved when the anthers on induction medium were with 30 Gy of gamma rays. The change of free amino acids in subcultured callus tissue in rice were investigated after callus were treated with cultured filtrate from Piricularia oryzae. Fourteen kinds of free amino acid could be quantitatively analysed, among which, contents of serine and glutamate were the highest and made up about 20% of total amino acids respectively. The total amino acids in callus tissue of resistant varieties before treated with cultured filtrate were higher than that of susceptible varieties. However the total amino acids were decreased in the resistant varieties and increased in the susceptible varieties after treatment with the filtrate. Arginine was found in the variety of Zhen Kong No. 13. Disease resistance of R 2 plants screened with toxin was increased. Five mutants with resistance to Piricularia oryzae were selected

  19. Induction of bacterial blight resistance in elite Indian rice cultivars using gamma-rays and ethyl methanesulfonate

    International Nuclear Information System (INIS)

    Agrawal, P.K.; Gosal, S.S.; Sidhu, G.S.

    2001-01-01

    Rice is the most important cereal crop in the world feeding more than 50 percent of the human population. During the last 30 years, induced mutation breeding has played a significant role in rice breeding programmes. Rice mutants with higher yield, greater tolerance to diseases and pests and other agronomic qualities have been released for commercial cultivation in many countries. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae is the second important disease in Southeast Asia. In the Basmati field sometime the yield loss is up to 100%. Moreover, there is no resistance source available. In Basmati rice, which is known for its quality and aroma. Induction of bacterial blight resistance in Basmati will help in developing high yielding Basmati type cultivars without compromising the quality

  20. Coincidence in map positions between pathogen-induced defense-responsive genes and quantitative resistance loci in rice

    Institute of Scientific and Technical Information of China (English)

    熊敏; 王石平; 张启发

    2002-01-01

    Quantitative disease resistance conferred by quantitative trait loci (QTLs) is presumably of wider spectrum and durable. Forty-four cDNA clones, representing 44 defense-responsive genes, were fine mapped to 56 loci distributed on 9 of the 12 rice chromosomes. The locations of 32 loci detected by 27 cDNA clones were associated with previously identified resistance QTLs for different rice diseases, including blast, bacterial blight, sheath blight and yellow mottle virus. The loci detected by the same multiple-copy cDNA clones were frequently located on similar locations of different chromosomes. Some of the multiple loci detected by the same clones were all associated with resistance QTLs. These results suggest that some of the genes may be important components in regulation of defense responses against pathogen invasion and they may be the candidates for studying the mechanism of quantitative disease resistance in rice.

  1. Metabolite profiles of rice cultivars containing bacterial blight-resistant genes are distinctive from susceptible rice

    Institute of Scientific and Technical Information of China (English)

    Jiao Wu; Haichuan Yu; Haofu Dai; Wenli Mei; Xin Huang; Shuifang Zhu; Ming Peng

    2012-01-01

    The metabolic changes of bacterial blight-resistant line C418/Xa23 generated by molecular marker-assisted selection (n =12),transgenic variety C418-Xa21 generated by using the Agrobacterium-mediated system (n =12),and progenitor cultivar C418 (n =12) were monitored using gas chromatography/mass spectrometry.The validation,discrimination,and establishment of correlative relationships between metabolite signals were performed by cluster analysis,principal component analysis,and partial least squares-discriminant analysis.Significant and unintended changes were observed in 154 components in C418/Xa23 and 48 components in C418-Xa21 compared with C418 (P < 0.05,Fold change > 2.0).The most significant decreases detected (P< 0.001) in both C418/Xa23 and C418-Xa21 were in three amino acids: glycine,tyrosine,and alanine,and four identified metabolites: malic acid,ferulic acid,succinic acid,and glycerol.Linoleic acid was increased specifically in C418/Xa23 which was derived from traditional breeding.This line,possessing a distinctive metabolite profile as a positive control,shows more differences vs.the parental than the transgenic line.Only succinic acid that falls outside the boundaries of natural variability between the two non-transgenic varieties C418 and C418/Xa23 should be further investigated with respect to safety or nutritional impact.

  2. Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance

    Directory of Open Access Journals (Sweden)

    Jegadeesan Ramalingam

    2017-06-01

    Full Text Available Bacterial blight (BB, caused by Xanthomonas oryzae pv.oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes (xa5, xa13, and Xa21 in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes (xa5, xa13, and Xa21 in maintainer lines (CO 2B, CO 23B, and CO 24B of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A through functional markers assisted back cross breeding. IRBB60 with xa5, xa13, and Xa21 genes is used as a donor parent. BC2F1 and BC2F2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC2F1, plants with all three resistance genes (xa5, xa13, and Xa21 and high parent genome recovery was identified. In BC2F2, plants with all resistance genes and without fertility restorer (Rf3 and Rf4 were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line, test crosses were made to develop new rice hybrids. Hybrids combinations viz., CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13, and Xa21 genes in a separate breeding program. These new hybrids with resistance against bacterial blight

  3. Rice fissure resistance QTLs from ‘Saber’ complement those from ‘Cypress’

    Science.gov (United States)

    The economic value of broken rice is about half that of whole milled rice, so one goal of producers, millers, and rice breeders is to reduce grain breakage during the dehusking and milling processes. One of the primary causes of rice breakage is fissuring, or cracking, of the rice before it enters ...

  4. Evaluating the non-rice host plant species of Sesamia inferens (Lepidoptera: Noctuidae) as natural refuges: resistance management of Bt rice.

    Science.gov (United States)

    Liu, Zhuorong; Gao, Yulin; Luo, Ju; Lai, Fengxiang; Li, Yunhe; Fu, Qiang; Peng, Yufa

    2011-06-01

    Although rice (Oryza sativa L.) lines that express Bacillus thuringiensis (Bt) toxins have shown great potential for managing the major Lepidoptera pests of rice in southern China, including Sesamia inferens, their long-term use is dependent on managing resistance development to Bt toxins in pest populations. The maintenance of "natural" refuges, non-Bt expressing plants that are hosts for a target pest, has been proposed as a means to minimize the evolution of resistance to Bt toxins in transgenic plants. In the current study, field surveys and greenhouse experiments were conducted to identify host plants of S. inferens that could serve as "natural" refuges in rice growing areas of southern China. A field survey showed that 34 plant species in four families can be alternative host plants of S. inferens. Based on injury level under field conditions, rice (Oryza sativa L.); water oat (Zizania latifolia Griseb.); corn (Zea mays L.); tidalmarsh flatsedge (Cyperus serotinus Rottb.); and narrow-leaved cat-tail (Typha angustifolia Linn.) were identified as the primary host plant species of S. inferens. Greenhouse experiments further demonstrated that water oat, corn, and narrow-leaved cat-tail could support the survival and development of S. inferens. Interestingly, greenhouse experiments showed that S. inferens preferred to lay eggs on tidalmarsh flatsedge compared with the other three nonrice host species, although no pupae were found in the plants examined in field surveys. Few larvae were found to survive on tidalmarsh flatsedge in greenhouse bioassays, suggesting that tidalmarsh flatsedge could serve as a "dead-end" trap crop for S. inferens, but is not a candidate to serve as natural refuge to maintain susceptible S. inferens. Overall, these results suggest that water-oat, corn, and narrow-leaved cat-tail might serve as "natural refuge" for S. inferens in rice planting area of southern China when Bt rice varieties are planted.

  5. Novel Digital Features Discriminate Between Drought Resistant and Drought Sensitive Rice Under Controlled and Field Conditions

    Directory of Open Access Journals (Sweden)

    Lingfeng Duan

    2018-04-01

    Full Text Available Dynamic quantification of drought response is a key issue both for variety selection and for functional genetic study of rice drought resistance. Traditional assessment of drought resistance traits, such as stay-green and leaf-rolling, has utilized manual measurements, that are often subjective, error-prone, poorly quantified and time consuming. To relieve this phenotyping bottleneck, we demonstrate a feasible, robust and non-destructive method that dynamically quantifies response to drought, under both controlled and field conditions. Firstly, RGB images of individual rice plants at different growth points were analyzed to derive 4 features that were influenced by imposition of drought. These include a feature related to the ability to stay green, which we termed greenness plant area ratio (GPAR and 3 shape descriptors [total plant area/bounding rectangle area ratio (TBR, perimeter area ratio (PAR and total plant area/convex hull area ratio (TCR]. Experiments showed that these 4 features were capable of discriminating reliably between drought resistant and drought sensitive accessions, and dynamically quantifying the drought response under controlled conditions across time (at either daily or half hourly time intervals. We compared the 3 shape descriptors and concluded that PAR was more robust and sensitive to leaf-rolling than the other shape descriptors. In addition, PAR and GPAR proved to be effective in quantification of drought response in the field. Moreover, the values obtained in field experiments using the collection of rice varieties were correlated with those derived from pot-based experiments. The general applicability of the algorithms is demonstrated by their ability to probe archival Miscanthus data previously collected on an independent platform. In conclusion, this image-based technology is robust providing a platform-independent tool for quantifying drought response that should be of general utility for breeding and functional

  6. Genetic study of resistance to inhibitory effects of UV radiation in rice (Oryza sativa)

    International Nuclear Information System (INIS)

    Sato, T.; Kang, H.S.; Kumagai, T.

    1994-01-01

    Genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice (Oryza sativa L.) cultivars was carried out. Some experimental plants were grown in visible radiation supplemented with UV radiation containing a large amount of UV-B and a small amount of UV-C in a phytotron, while others were grown without UV radiation. The degree of resistance to UV radiation was estimated in terms of the degree of reduction caused by supplemental UV radiation in the fresh weight of the aboveground plant parts and the chlorophyll content per unit fresh weight. Fresh weight and chlorophyll content in F 2 plants generated by reciprocally crossing cv. Sasanishiki, a cultivar more resistant to UV radiation, and Norin 1, a cultivar less resistant to such radiation exhibited a normal frequency distribution. The heritabilities of these two properties in F 2 plants were low under conditions of non-supplemental UV radiation. Under elevated UV radiation, the F 2 population shifted to the lower range of fresh weight and chlorophyll content, and the means were close to those of Norin 1. The heritabilities of these two properties were the same in the reciprocal crosses, indicating that maternal inheritance was not involved. Inheritance of chlorophyll content per unit fresh weight was further determined in F 3 lines generated by self-fertilizing F 2 plants of Sasanishiki and Norin 1. The results showed that the F 3 population was segregated into three genotypes, namely, resistant homozygotes, segregated heterozygotes and sensitive homozygotes, with a ratio of 1:65:16. It was thus evident that the resistance to the inhibitory effect of elevated UV radiation in these rice plants was controlled by recessive polygenes. (author)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xiaoyan; Mou, Renxiang; Cao, Zhaoyun; Xu, Ping; Wu, Xiaoliang; Zhu, Zhiwei; Chen, Mingxue, E-mail: cmingxue@126.com

    2016-11-01

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

  9. XA23 is an executor R protein and confers broad-spectrum disease resistance in rice.

    Science.gov (United States)

    Wang, Chunlian; Zhang, Xiaoping; Fan, Yinglun; Gao, Ying; Zhu, Qinlong; Zheng, Chongke; Qin, Tengfei; Li, Yanqiang; Che, Jinying; Zhang, Mingwei; Yang, Bing; Liu, Yaoguang; Zhao, Kaijun

    2014-11-09

    The majority of plant disease resistance (R) genes encode proteins that share common structural features. However, the transcription activator-like effector (TALE) associated executor type R genes show no considerable sequence homology to any known R genes. We adopted a map-based cloning approach and TALE-based technology to isolate and characterize Xa23, a new executor R gene derived from the wild rice (Oryza rufipogon) that confers an extremely broad spectrum of resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo). Xa23 encodes a 113-amino acid protein that shares 50% identity to the known executor R protein XA10. The predicted transmembrane helices in XA23 also overlap with those of XA10. Unlike Xa10, however, Xa23 transcription is specifically activated by AvrXa23, a TALE present in all examined Xoo field isolates. Moreover, the susceptible xa23 allele has an identical open reading frame of Xa23, but differs in promoter region by lacking the TALE binding-element (EBE) for AvrXa23. XA23 can trigger strong hypersensitive response in rice, tobacco and tomato. Our results provide the first evidence that plant genomes have an executor R gene family in which members execute their function and spectrum of disease resistance by recognizing the cognate TALEs in pathogen. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  10. Development and evaluation of near-isogenic lines for brown planthopper resistance in rice cv. 9311

    OpenAIRE

    Cong Xiao; Jie Hu; Yi-Ting Ao; Ming-Xing Cheng; Guan-Jun Gao; Qing-Lu Zhang; Guang-Cun He; Yu-Qing He

    2016-01-01

    Brown planthopper (BPH) is the most destructive pest of rice in Asia. To date 29 BPH resistance genes have been identified, but only a few genes are being used in breeding due to inefficient markers for marker-assisted selection (MAS) and little knowledge of the real effects of the genes. In this study we individually transferred 13 genes or QTLs (Bph14, QBph3, QBph4, Bph17, Bph15, Bph20, Bph24, Bph6, Bph3, Bph9, Bph10, Bph18 and Bph21) into cultivar 9311 by marker assisted backcross breeding...

  11. Estimation of genetic divergence in rice (oryza sativa l) germplasms on the basis of paddy yield and rice stem borer's (pyralidae: lepidoptera) resistance

    International Nuclear Information System (INIS)

    Sarwar, M.

    2013-01-01

    Field trials were carried out to estimate resistance along with paddy yield in 55 rice germplasm lines (35 aromatic and 20 non-aromatic genotypes) for rice stem borers (Pyralidae: Lepidoptera) to expose their potential in pest management approach. The results expressed significant differences for pest damage build-up and paddy yield among the rice germplasm lines. The findings clearly portrayed that based upon the percentage of pest invasions (dead hearts and white heads damage), no genotype was exclusively resistant to stem borers damage under field conditions. Two aromatic genotypes, Jajai-15A/97 and Basmati-Cr-34, exhibited least borers prevalence and amplified paddy yield while Sonehri Sugdasi (P) and Sada Gulab (P) pointed out a peak pest invasion and declined paddy yield. The estimation of pest incidence build-up and paddy productivity within non-aromatic genotypes confirmed that IR8 (P), IR6-15-2 and IR6 (P) were mainly proficient for bearing condensed pest invasion and augmented paddy yield. IR8-2.5-4, IR6-15-10 and IR6-20-9 demonstrated elevated pest susceptibility and gave poor yield. Rest of the germplasms appeared to be least tolerant or vulnerable to pest build-up and reduced paddy production. The tolerant and high yielding genotypes should be popularised in rice borers endemic areas and can be used in varietals resistance breeding strategy. The outcome of current studies necessitates the integration of existing host plant tolerance along with other management strategies to accomplish a suitable control of rice stem borers and enhance paddy yield. (author)

  12. Inheritance patterns and identification of microsatellite markers linked to the rice blast resistance in BC2F1 population of rice breeding

    Directory of Open Access Journals (Sweden)

    Gous Miah

    2015-03-01

    Full Text Available The BC2F1 population was derived from a cross between rice variety, MR219 (susceptible to blast and Pongsu Seribu 1 (resistant to blast. The objectives of this research were to know the inheritance pattern of blast resistance and to identify the linked markers associated with blast resistance in BC2F1 population. Sixteen microsatellite markers were found as polymorphic between the parents related to blast resistant genes (Pi-genes. Among the selected blast resistant linked markers, two markers RM6836 and RM8225 showed expected testcross ratio (1:1 for single-gene model in the BC2F1 population with the association between resistant and susceptible progeny. A total of 333-BC2F1 plants were challenged with the most virulent pathotype P7.2 of Magnaporthe oryzae. Chi-square (χ2 analysis for phenotypic segregation in single-gene model showed goodness of fit (P = 0.4463 to the expected segregation ratio (1:1. In marker segregation analysis, two polymorphic markers (RM6836 and RM8225 clearly showed goodness of fit to the expected segregation testcross ratio (1:1 for the single-gene model. The marker RM8225 and RM6836 showed significant R2 values higher than 10 for the trait of the blast lesions degree (BLD. The positions of RM6836 and RM8225 markers on rice chromosome 6 and the distance between these two markers is 0.2 cM. We conclude that single dominant gene control the blast resistance in Pongsu Seribu 1 located on chromosome 6, which is linked to RM8225 and RM6836 microsatellite markers. This information could be useful in marker-assisted selection for blast resistance in rice breeding involving Pongsu Seribu 1.

  13. Simple screening strategy with only water bath needed for the identification of insect-resistant genetically modified rice.

    Science.gov (United States)

    Zhang, Fang; Wang, Liu; Wang, Rui; Ying, Yibin; Wu, Jian

    2015-02-03

    An informative, with simple instrument needed, rapid and easily updated strategy for the identification of insect-resistant genetically modified (GM) rice has been described. Such strategy is based on a parallel series of loop-mediated isothermal amplification (LAMP) reactions targeting the rice endogenous gene sucrose phosphate synthase (Sps), the top two most frequently used genetic elements (Agrobacterium tumefaciens nopaline synthase terminator (Nos) and Cauliflower mosaic virus 35S promoter (CaMV35S)), and an insect-resistant specific gene (Cry1Ac) and detected visually by phosphate ion (Pi)-induced coloration reaction. After a logical judgment of visible readouts has been obtained, three popular insect-resistant GM rice events in China can be successfully identified within 35 min, using either microwell strips or paper bases.

  14. A review of microsatellite markers and their applications in rice breeding programs to improve blast disease resistance.

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Islam, Kh Nurul; Latif, Mohammad Abdul

    2013-11-14

    Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR), and they are typically composed of 1-6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS) can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS in rice breeding

  15. A Review of Microsatellite Markers and Their Applications in Rice Breeding Programs to Improve Blast Disease Resistance

    Directory of Open Access Journals (Sweden)

    Mohammad Abdul Latif

    2013-11-01

    Full Text Available Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR, and they are typically composed of 1–6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS

  16. A novel blast resistance gene, Pi54rh cloned from wild species of rice, Oryza rhizomatis confers broad spectrum resistance to Magnaporthe oryzae.

    Science.gov (United States)

    Das, Alok; Soubam, D; Singh, P K; Thakur, S; Singh, N K; Sharma, T R

    2012-06-01

    The dominant rice blast resistance gene, Pi54 confers resistance to Magnaporthe oryzae in different parts of India. In our effort to identify more effective forms of this gene, we isolated an orthologue of Pi54 named as Pi54rh from the blast-resistant wild species of rice, Oryza rhizomatis, using allele mining approach and validated by complementation. The Pi54rh belongs to CC-NBS-LRR family of disease resistance genes with a unique Zinc finger (C(3)H type) domain. The 1,447 bp Pi54rh transcript comprises of 101 bp 5'-UTR, 1,083 bp coding region and 263 bp 3'-UTR, driven by pathogen inducible promoter. We showed the extracellular localization of Pi54rh protein and the presence of glycosylation, myristoylation and phosphorylation sites which implicates its role in signal transduction process. This is in contrast to other blast resistance genes that are predicted to be intracellular NBS-LRR-type resistance proteins. The Pi54rh was found to express constitutively at basal level in the leaves, but upregulates 3.8-fold at 96 h post-inoculation with the pathogen. Functional validation of cloned Pi54rh gene using complementation test showed high degree of resistance to seven isolates of M. oryzae collected from different geographical locations of India. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54rh cloned from wild species of rice provides broad spectrum resistance to M. oryzae hence can be used in rice improvement breeding programme.

  17. Fine mapping and characterization of BPH27, a brown planthopper resistance gene from wild rice (Oryza rufipogon Griff.).

    Science.gov (United States)

    Huang, D; Qiu, Y; Zhang, Y; Huang, F; Meng, J; Wei, S; Li, R; Chen, B

    2013-01-01

    The brown planthopper (Nilaparvata lugens Stål; BPH) is one of the most serious rice pests worldwide. Growing resistant varieties is the most effective way to manage this insect, and wild rice species are a valuable source of resistance genes for developing resistant cultivars. BPH27 derived from an accession of Guangxi wild rice, Oryza rufipogon Griff. (Accession no. 2183, hereafter named GX2183), was primarily mapped to a 17-cM region on the long arm of the chromosome four. In this study, fine mapping of BPH27 was conducted using two BC(1)F(2) populations derived from introgression lines of GX2183. Insect resistance was evaluated in the BC(1)F(2) populations with 6,010 individual offsprings, and 346 resistance extremes were obtained and employed for fine mapping of BPH27. High-resolution linkage analysis defined the BPH27 locus to an 86.3-kb region in Nipponbare. Regarding the sequence information of rice cultivars, Nipponbare and 93-11, all predicted open reading frames (ORFs) in the fine-mapping region have been annotated as 11 types of proteins, and three ORFs encode disease-related proteins. Moreover, the average BPH numbers showed significant differences in 96-120 h after release in comparisons between the preliminary near-isogenic lines (pre-NILs, lines harboring resistance genes) and BaiR54. BPH growth and development were inhibited and survival rates were lower in the pre-NIL plants compared with the recurrent parent BaiR54. The pre-NIL exhibited 50.7% reductions in population growth rates (PGR) compared to BaiR54. The new development in fine mapping of BPH27 will facilitate the efforts to clone this important resistant gene and to use it in BPH-resistance rice breeding.

  18. Diverse Rice Landraces of North-East India Enables the Identification of Novel Genetic Resources for Magnaporthe Resistance.

    Science.gov (United States)

    Umakanth, Bangale; Vishalakshi, Balija; Sathish Kumar, P; Rama Devi, S J S; Bhadana, Vijay Pal; Senguttuvel, P; Kumar, Sudhir; Sharma, Susheel Kumar; Sharma, Pawan Kumar; Prasad, M S; Madhav, Maganti S

    2017-01-01

    North-East (NE) India, the probable origin of rice has diverse genetic resources. Many rice landraces of NE India were not yet characterized for blast resistance. A set of 232 landraces of NE India, were screened for field resistance at two different hotspots of rice blast, viz., IIRR-UBN, Hyderabad and ICAR-NEH, Manipur in two consecutive seasons. The phenotypic evaluation as well as gene profiling for 12 major blast resistance genes ( Pitp , Pi33 , Pi54 , Pib , Pi20 , Pi38 , Pita2 , Pi1 , Piz , Pi9 , Pizt , and Pi40 ) with linked as well as gene-specific markers, identified 84 resistant landraces possessing different gene(s) either in singly or in combinations and also identified seven resistant landraces which do not have the tested genes, indicating the valuable genetic resources for blast resistance. To understand the molecular diversity existing in the population, distance and model based analysis were performed using 120 SSR markers. Results of both analyses are highly correlated by forming two distinct subgroups and the existence of high diversity (24.9% among the subgroups; 75.1% among individuals of each subgroup) was observed. To practically utilize the diversity in the breeding program, a robust core set having an efficiency index of 0.82 which consists of 33 landraces were identified through data of molecular, blast phenotyping, and important agro-morphological traits. The association of eight novel SSR markers for important agronomic traits which includes leaf and neck blast resistance was determined using genome-wide association analysis. The current study focuses on identifying novel resources having field resistance to blast as well as markers which can be explored in rice improvement programs. It also entails the development of a core set which can aid in representing the entire diversity for efficiently harnessing its properties to broaden the gene pool of rice.

  19. Development of heat resistant geopolymer-based materials from red mud and rice husk ash

    Science.gov (United States)

    Thang, Nguyen Hoc; Nhung, Le Thuy; Quyen, Pham Vo Thi Ha; Phong, Dang Thanh; Khe, Dao Thanh; Van Phuc, Nguyen

    2018-04-01

    Geopolymer is an inorganic polymer composite developed by Joseph Davidovits in 1970s. Such material has potentials to replace Ordinary Portland Cement (OPC)-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in this study, red mud and rice husk ash were used as raw materials for geopolymeric production, which are aluminum industrial and agricultural wastes that need to be managed to reduce their negative impact to the environment. The red mud and rice husk ash were mixed with sodium silicate (water glass) solution to form geopolymer paste. The geopolymer paste was filled into 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room temperature for 28 days. These products were then tested for compressive strength and volumetric weight. Results indicated that the material can be considered lightweight with a compressive strength at 28 days that are in the range of 6.8 to 15.5 MPa. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000oC for 2 hours. Results suggest high heat resistance with an increase of compressive strength from 262% to 417% after exposed at high temperature.

  20. Transcriptome analysis highlights defense and signaling pathways mediated by rice pi21 gene with partial resistance to Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2016-12-01

    Full Text Available Rice blast disease is one of the most destructive rice diseases worldwide. The pi21 gene confers partial and durable resistance to Magnaporthe oryzae. However, little is known regarding the molecular mechanisms of resistance mediated by the loss-of-function of Pi21. In this study, comparative transcriptome profiling of the Pi21-RNAi transgenic rice line and Nipponbare with M. oryzae infection at different time points (0, 12, 24, 48, and 72 hpi were investigated using RNA sequencing. The results generated 43,222 unique genes mapped to the rice genome. In total, 1,109 differentially expressed genes (DEGs were identified between the Pi21-RNAi line and Nipponbare with M. oryzae infection, with 103, 281, 209, 69, and 678 DEGs at 0, 12, 24, 48, and 72 hpi, respectively. Functional analysis showed that most of the DEGs were involved in metabolism, transport, signaling, and defense. Among the genes assigned to plant–pathogen interaction, we identified 43 receptor kinase genes associated with pathogen-associated molecular pattern recognition and calcium ion influx. The expression levels of brassinolide-insensitive 1, flagellin sensitive 2 and elongation factor Tu receptor, ethylene (ET biosynthesis and signaling genes, were higher in the Pi21-RNAi line than Nipponbare. This suggested that there was a more robust PTI response in Pi21-RNAi plants and that ET signaling was important to rice blast resistance. We also identified 53 transcription factor genes, including WRKY, NAC, DOF, and ERF families that show differential expression between the two genotypes. This study highlights possible candidate genes that may serve a function in the partial rice blast resistance mediated by the loss-of-function of Pi21 and increase our understanding of the molecular mechanisms involved in partial resistance against M. oryzae.

  1. Chloroplast-expressed MSI-99 in tobacco improves disease resistance and displays inhibitory effect against rice blast fungus.

    Science.gov (United States)

    Wang, Yun-Peng; Wei, Zheng-Yi; Zhang, Yu-Ying; Lin, Chun-Jing; Zhong, Xiao-Fang; Wang, Yue-Lin; Ma, Jing-Yong; Ma, Jian; Xing, Shao-Chen

    2015-03-02

    Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

  2. Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

    Directory of Open Access Journals (Sweden)

    Yun-Peng Wang

    2015-03-01

    Full Text Available Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

  3. Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase gene are resistant to diphenyl ether herbicide oxyfluorfen.

    Science.gov (United States)

    Lee, H J; Lee, S B; Chung, J S; Han, S U; Han, O; Guh, J O; Jeon, J S; An, G; Back, K

    2000-06-01

    Protoporphyrinogen oxidase (Protox), the penultimate step enzyme of the branch point for the biosynthetic pathway of Chl and hemes, is the target site of action of diphenyl ether (DPE) herbicides. However, Bacillus subtilis Protox is known to be resistant to the herbicides. In order to develop the herbicide-resistant plants, the transgenic rice plants were generated via expression of B. subtilis Protox gene under ubiquitin promoter targeted to the cytoplasm or to the plastid using Agrobacterium-mediated gene transformation. The integration and expression of the transgene were investigated at T0 generation by DNA and RNA blots. Most transgenic rice plants revealed one copy transgene insertion into the rice genome, but some with 3 copies. The expression levels of B. subtilis Protox mRNA appeared to correlate with the copy number. Furthermore, the plastidal transgenic lines exhibited much higher expression of the Protox mRNA than the cytoplasmic transgenic lines. The transgenic plants expressing the B. subtilis Protox gene at T0 generation were found to be resistant to oxyfluorfen when judged by cellular damage with respect to cellular leakage, Chl loss, and lipid peroxidation. The transgenic rice plants targeted to the plastid exhibited higher resistance to the herbicide than the transgenic plants targeted to the cytoplasm. In addition, possible resistance mechanisms in the transgenic plants to DPE herbicides are discussed.

  4. Tagging microsatellite marker to a blast resistance gene in the irrigated rice cultivar Cica-8

    Directory of Open Access Journals (Sweden)

    Thiago Martins Pinheiro

    2012-09-01

    Full Text Available The rice cultivar Cica-8 exhibit differential reaction to several pathotypes of Magnaporthe oryzae. The objective of the present investigation was to determine the number of alleles involved in the expression of resistance to leaf blast and identify microsatellite markers linked to these alleles. A cross between cultivar Metica-1 and Cica-8 susceptible and resistant, respectively, to pathotype IB-1 (Py1049 was made to obtain F1, F2, BC1:1 and BC1:2 progenies. Greenhouse tests for leaf blast reaction showed that resistance is controlled by a monogenic dominant gene. For testing microsatellite markers, DNA of both resistant and susceptible parents and F1 and F2 populations was extracted. As expected for single dominant gene the F2 populations segregated at a ratio of 3:1. Of the 11 microsatellite markers tested, one marker RM 7102 was found to be closely linked to the resistant allele at a distance of 2.7 cM, in the cultivar Cica-8 to pathotype IB-1.

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

    International Nuclear Information System (INIS)

    Xiao Wuming; Wang Hui; Liu Yongzhu; Guo Tao; Chen Zhiqiang; Yang Qiyun; Zhu Xiaoyuan

    2012-01-01

    The main agronomic traits and resistance to rice blast of 34 space-induced lines from an elite rice cultivar, Zhong-er-ruan-zhan were evaluated at their SP 4 . The resistance to blast of the mutant lines had been tested by two blast isolates previously. It was found that the mutant lines showed significant difference in plant height, effective panicles, panicle length and grains per panicle etc. from their parent. The range of variation in 1000-grain weight the largest, followed by the seed-setting rate, and that of effective panicles was the least among all the traits. Except for the line Z34, 33 mutant lines had broader resistance spectra than the wild-type based on the test with 38 different blast isolates, and all the 33 lines were also resistant to the panicle blast in the field. The result confirmed that selection for resistant to blast in lower generations was reliable. Taking account of agronomic traits and blast resistance, promising lines with resistance to blast and good agronomic characters could be selected from those mutant lines. Therefore, the elite rice germplasm with enhanced disease resistance can be produced. (authors)

  6. Development and characterization of japonica rice lines carrying the brown planthopper-resistance genes BPH12 and BPH6.

    Science.gov (United States)

    Qiu, Yongfu; Guo, Jianping; Jing, Shengli; Zhu, Lili; He, Guangcun

    2012-02-01

    The brown planthopper (Nilaparvata lugens Stål; BPH) has become a severe constraint on rice production. Identification and pyramiding BPH-resistance genes is an economical and effective solution to increase the resistance level of rice varieties. All the BPH-resistance genes identified to date have been from indica rice or wild species. The BPH12 gene in the indica rice accession B14 is derived from the wild species Oryza latifolia. Using an F(2) population from a cross between the indica cultivar 93-11 and B14, we mapped the BPH12 gene to a 1.9-cM region on chromosome 4, flanked by the markers RM16459 and RM1305. In this population, BPH12 appeared to be partially dominant and explained 73.8% of the phenotypic variance in BPH resistance. A near-isogenic line (NIL) containing the BPH12 locus in the background of the susceptible japonica variety Nipponbare was developed and crossed with a NIL carrying BPH6 to generate a pyramid line (PYL) with both genes. BPH insects showed significant differences in non-preference in comparisons between the lines harboring resistance genes (NILs and PYL) and Nipponbare. BPH growth and development were inhibited and survival rates were lower on the NIL-BPH12 and NIL-BPH6 plants compared to the recurrent parent Nipponbare. PYL-BPH6 + BPH12 exhibited 46.4, 26.8 and 72.1% reductions in population growth rates (PGR) compared to NIL-BPH12, NIL-BPH6 and Nipponbare, respectively. Furthermore, insect survival rates were the lowest on the PYL-BPH6 + BPH12 plants. These results demonstrated that pyramiding different BPH-resistance genes resulted in stronger antixenotic and antibiotic effects on the BPH insects. This gene pyramiding strategy should be of great benefit for the breeding of BPH-resistant japonica rice varieties.

  7. Acetylated rice starches films with different levels of amylose: Mechanical, water vapor barrier, thermal, and biodegradability properties.

    Science.gov (United States)

    Colussi, Rosana; Pinto, Vânia Zanella; El Halal, Shanise Lisie Mello; Biduski, Bárbara; Prietto, Luciana; Castilhos, Danilo Dufech; Zavareze, Elessandra da Rosa; Dias, Alvaro Renato Guerra

    2017-04-15

    Biodegradable films from native or acetylated starches with different amylose levels were prepared. The films were characterized according to the mechanical, water vapor barrier, thermal, and biodegradability properties. The films from acetylated high amylose starches had higher moisture content and water solubility than the native high amylose starch film. However, the acetylation did not affect acid solubility of the films, regardless of the amylose content. Films made from high and medium amylose rice starches were obtained; however low amylose rice starches, whether native or acetylated, did not form films with desirable characteristics. The acetylation decreased the tensile strength and increased the elongation of the films. The acetylated starch-based films had a lower decomposition temperature and higher thermal stability than native starch films. Acetylated starches films exhibited more rapid degradation as compared with the native starches films. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The use of P-32 for determining varietal resistance of rice to brown planthopper (Nilaparvata lugens stal)

    International Nuclear Information System (INIS)

    Kuswadi, Achmad Nasroh

    1981-01-01

    The resistance was assessed uased on the feeding activities of the insect on 15-day old seedling of six test varietes namely TN 1, Asahan, Brantas, Citarum, Serayu and Mudgo. A level of 175 μCi per seedling appeared to give sufficiently high absorption of radiophosphorus by the brown planthoppers. The level of radioactivity in the brown planthopper fed for 24 hours on labelled rice plants appeared to be correlated with the susceptibility of the rice plant to brown planthopper. The radioactivity in the honeydew of those hoppers was less correlated with the rice susceptibility. The promising resistance screening method using P-32 tracer is thus more reliable when the radioactivity is detected in the insect rather than in the honeydew. (author)

  9. Resistance monitoring and cross-resistance patterns of three rice planthoppers, Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus to dinotefuran in China.

    Science.gov (United States)

    Mu, Xi-Chao; Zhang, Wei; Wang, Li-Xiang; Zhang, Shuai; Zhang, Kai; Gao, Cong-Fen; Wu, Shun-Fan

    2016-11-01

    Three rice planthoppers, brown planthopper, Nilaparvata lugens, white-backed planthopper, Sogatella furcifera and small brown planthopper, Laodelphax striatellus, are important pests of cultivated rice in tropical and temperate Asia. They have caused severe economic loss and developed resistance to insecticides from most chemical classes. Dinotefuran is the third neonicotinoid which possesses a broad spectrum and systemic insecticidal activity. We determined the susceptibility of dinotefuran to field populations from major rice production areas in China from 2013 to 2015. All the populations of S. furcifera and L. striatellus were kept susceptible to dinotefuran (0.7 to 1.4-fold of S. furcifera and 1.1-to 3.4-fold of L. striatellus) However, most strains of N. lugens (except FQ15) collected in 2015 had developed moderate resistance to dinotefuran, with resistance ratios (RR) ranging from 23.1 to 100.0 folds. Cross-resistance studies showed that chlorpyrifos-resistant and buprofezin-resistant Sogatella furcifera, chlorpyrifos-resistant and fipronil-resistant L. striatellus, imidacloprid-resistant and buprofezin-resistant Nilaparvata lugens exhibited negligible or no cross-resistance to dinotefuran. Synergism tests showed that piperonyl butoxide (PBO) produced a high synergism of dinotefuran effects in the DY15 and JS15 populations (2.14 and 2.52-fold, respectively). The obvious increase in resistance to dinotefuran in N. lugens indicates that insecticide resistance management strategies are urgently needed to prevent or delay further increase of insecticide resistance in N. lugens. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Evaluation of sulfate resistance of cement mortars containing black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2009-03-01

    In this paper, black rice husk ashes (BRHAs), which are agrowastes from an electricity generating power plant and a rice mill, were ground and used as a partial cement replacement. The durability of mortars under sulfate attack including expansion and compressive strength loss were investigated. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 30%, and 50% by weight of binder. The water-to-binder ratios were 0.55 and 0.65. For the durability of mortar exposed to sulfate attack, 5% sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions were used. As a result, when increasing the percentage replacement of BRHA, the expansion and compressive strength loss of mortar decreased. At the replacement levels of 30% and 50% of BRHA, the expansion of the mortars was less than those mixed with sulfate-resistant cement. However, the expansion of the mortars exposed to Na2SO4 was more than those exposed to MgSO4. Increasing the replacement level of BRHA tends to reduce the compressive strength loss of mortars exposed to Na2SO4 attack. In contrary, under MgSO4 attack, when increasing the replacement level of BRHA, the compressive strength loss increases from 0% to 50% in comparison to Portland cement mortar. Results show that ground BRHA can be applied as a pozzolanic material to concrete and also improve resistance to sodium sulfate attack, but it can impair resistance to magnesium sulfate attack.

  11. New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.

    Directory of Open Access Journals (Sweden)

    Ayako Okuno

    Full Text Available Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA, and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass.

  12. New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.

    Science.gov (United States)

    Okuno, Ayako; Hirano, Ko; Asano, Kenji; Takase, Wakana; Masuda, Reiko; Morinaka, Yoichi; Ueguchi-Tanaka, Miyako; Kitano, Hidemi; Matsuoka, Makoto

    2014-01-01

    Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA)-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA), and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass.

  13. Aluminum resistance transcription factor 1 (ART1) contributes to natural variation in rice aluminum resistance

    Science.gov (United States)

    Transcription factors (TFs) mediate stress resistance indirectly via physiological mechanisms driven by the array of genes they regulate. Therefore, when studying TF-mediated stress resistance, it is important to understand how TFs interact with different genetic backgrounds. Here, we fine-mapped th...

  14. Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development

    Directory of Open Access Journals (Sweden)

    Yongxiang Liao

    2018-03-01

    Full Text Available Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 (lmm9150, exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H2O2. Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610 in lmm9150. Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150. Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150. Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

  15. Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development.

    Science.gov (United States)

    Liao, Yongxiang; Bai, Que; Xu, Peizhou; Wu, Tingkai; Guo, Daiming; Peng, Yongbin; Zhang, Hongyu; Deng, Xiaoshu; Chen, Xiaoqiong; Luo, Ming; Ali, Asif; Wang, Wenming; Wu, Xianjun

    2018-01-01

    Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA) synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 ( lmm9150 ), exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H 2 O 2 . Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610) in lmm9150 . Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150 . Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150 . Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

  16. Application of autoclaving-cooling cycling treatment to improve resistant starch content of corn-based rice analogues

    Science.gov (United States)

    Hidayat, B.; Muslihudin, M.; Akmal, S.

    2018-01-01

    Resistant starch is one important component determining the characteristics of a functional food. The aim of the research was to determine the cooling time optimum in the autoclaving-cooling treatment to increase the resistance starch content corn-based rice analogues, with 6 level of cooling time (0 hours/control, 12 hours, 24 hours, 36 hours, 48 hours and 60 hours). The results showed that cooling at 4°C for 60 hours would increase the resistant starch content (6.27% to 15.38%), dietary fiber content (14.53% to 20.17%); and decrease the digestible starch content (61.81% to 52.70%). Cooling time level at 4°C for 24 hours, would increase the sensory score of corn-based rice analogues then back down until cooling time level of 60 hours. Microscopic analysis of granular structure using SEM indicated that cooling time had a linear correlation with cracks intensity on the granule surface of the corn-based rice analogues. The high content of resistant starch showed that the application of cooling time level at 4°C for 24 hours would improve the functional properties of corn-based rice analogues with sensory characteristics remain favorable to panelists.

  17. Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed Rotation System

    Directory of Open Access Journals (Sweden)

    Xing-bin DU

    2014-07-01

    Full Text Available To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice (WDR variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding (NTDS mode and conventional tillage direct seeding (CTDS mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0–5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5–20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.

  18. THE SEGREGATION PATTERN OF INSECT RESISTANCE GENES IN THE PROGENIES AND CROSSES OF TRANSGENIC ROJOLELE RICE

    Directory of Open Access Journals (Sweden)

    Satoto Satoto

    2016-10-01

    Full Text Available Successful application of genetic transformation technique, especially in developing rice variety resistant to brown plant hopper and stem borer, will depend on transgene being expressed and the gene inherited in a stable and predictable manner. This study aimed to analyse transgene segregation pattern of the progenies and the crosses of transgenic rice cv. Rojolele harboring cry1Ab and gna genes. The third generation (T2 of fivetransgenic Rojolele events containing gna and/or cry1Ab were evaluated for two generations to identify the homozygous lines and to study their inheritance. The homozygous lines were selected based on the result of PCR technique. The segregation patterns of gna and cry1Ab were studied in eight F2 populations derived from Rojolele x transgenic Rojolele homozygous for cry1Ab and or gna and their reciprocal crosses. Data  resulted from PCR of F2 population were analysed using a Chi Square test. The study obtained six homozygous lines for gna, namely A22- 1-32, A22-1-37, C72-1-9, F11-1-48, K21-1-39, K21-1-48, and two homozygous lines for cry1Ab, namely K21-1-39 and K21- 1-48. Both cry1Ab and gna transgenes had been inherited through selfing and crossing with their wild type as indicated from the F1 containing gna and cry1Ab as many as 48.4% and 47.4%, respectively. In six of the eight crosses, gna was inherited in a 3:1 ratio consistent with Mendelian inheritance of a single dominant locus, while in the remaining two crosses, gna was segregated in a 1:1 ratio. The presence of cry1Ab in F2 populations also showed a 3:1 segregation ratio in all crosses. In the F2 population derived from F1 plant containing cry1Ab and gna, both transgenes segregated in a 9:3:3:1 dihybrid segregation ratio. This study will add to the diversity of genetic sources for insect resistance and allow further use of these transgenic lines for pyramiding resistance to brown plant hopper and stem borer or  separately in rice breeding programs whenever

  19. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    Science.gov (United States)

    Huangfu, Jiayi; Li, Jiancai; Li, Ran; Ye, Meng; Kuai, Peng; Zhang, Tongfang; Lou, Yonggen

    2016-01-01

    WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens) and by treatment with jasmonic acid (JA) or salicylic acid (SA). The antisense expression of OsWRKY45 (as-wrky) enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT) plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani) but higher susceptibility to rice blast (caused by Magnaporthe oryzae) than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice. PMID:27258255

  20. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    Directory of Open Access Journals (Sweden)

    Jiayi Huangfu

    2016-05-01

    Full Text Available WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens and by treatment with jasmonic acid (JA or salicylic acid (SA. The antisense expression of OsWRKY45 (as-wrky enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani but higher susceptibility to rice blast (caused by Magnaporthe oryzae than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice.

  1. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens.

    Science.gov (United States)

    Huangfu, Jiayi; Li, Jiancai; Li, Ran; Ye, Meng; Kuai, Peng; Zhang, Tongfang; Lou, Yonggen

    2016-05-31

    WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens) and by treatment with jasmonic acid (JA) or salicylic acid (SA). The antisense expression of OsWRKY45 (as-wrky) enhanced BPH-induced levels of H₂O₂ and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT) plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani) but higher susceptibility to rice blast (caused by Magnaporthe oryzae) than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice.

  2. Lodging Resistance of Japonica Rice (Oryza Sativa L.): Morphological and Anatomical Traits due to top-Dressing Nitrogen Application Rates.

    Science.gov (United States)

    Zhang, Wujun; Wu, Longmei; Wu, Xiaoran; Ding, Yanfeng; Li, Ganghua; Li, Jingyong; Weng, Fei; Liu, Zhenghui; Tang, She; Ding, Chengqiang; Wang, Shaohua

    2016-12-01

    Lodging in rice production often limits grain yield and quality by breaking or bending stems. Excessive nitrogen (N) fertilizer rates are the cause of poor lodging resistance in rice, but little is known about the effect of top-dressing N application rates on the mechanical strength of japonica rice plants, especially how the anatomical structure in culms is affected by N. In this study, field experiments on two japonica rice varieties with three top-dressing N application rates, 0 kg N ha(-1) (LN), 135 kg N ha(-1) (MN), and 270 kg N ha(-1) (HN) as urea, were conducted. Wuyunjing23, a lodging-resistant japonica rice cultivar and W3668, a lodging-susceptible japonica rice cultivar were used. The lodging index, breaking strength, morphological and anatomical traits in culms were measured in this study. The visual lodging rate in japonica rice differed remarkably between genotypes and top-dressing N treatments. The higher lodging index of rice plants was primarily attributed to the weak breaking strength of the lower internodes. The longer elongated basal internodes were responsible for higher plant height and a higher lodging index. Correlation analysis showed that breaking strength was significantly and positively correlated with the thickness of the mechanical tissue but was significantly and negatively correlated with the inner diameter of the major axis (b2). With increasing top-dressing N rates, the sclerenchyma cells of the mechanical tissues and the vascular bundles of the Wuyunjing23 cultivar varied little. The plant height, inner diameter of the minor axis (a2) and b2 increased significantly, but the area of the large vascular bundle (ALVB) and the area of the small vascular bundle (ASVB) decreased significantly and resulted in lower stem strength and a higher lodging index under higher top-dressing N conditions. The culm diameter of the W3668 cultivar increased slightly with no significant difference, and the sclerenchyma cells in the mechanical

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

    Science.gov (United States)

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

    2016-11-01

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

  4. Pyramiding and evaluation of three dominant brown planthopper resistance genes in the elite indica rice 9311 and its hybrids.

    Science.gov (United States)

    Hu, Jie; Cheng, Mingxing; Gao, Guanjun; Zhang, Qinglu; Xiao, Jinghua; He, Yuqing

    2013-07-01

    Brown planthopper (BPH), Nilaparvata lugens Stål, is the most devastating insect pest in rice-producing areas. Three dominant BPH resistance genes (Bph14, Bph15, Bph18) were pyramided into elite indica rice 9311 and its hybrids using marker-assisted selection. Gene effectiveness was evaluated on the basis of seedling and adult rice resistance, honeydew weight and survival rate of BPH. All three genes affected BPH growth and development and antibiotic factors, resulting in both seedling and adult resistance. Bph15 had the greatest effect on conferring resistance to BPH. The results showed an additive effect of pyramiding genes, the order of the gene effect being 14/15/18 ≥ 14/15 > 15/18 ≥ 15 > 14/18 ≥ 14 ≥ 18 > none. The pyramided or single-gene introgression hybrids showed greater resistance than conventional hybrids, although the heterozygous genotypes had weaker effects than the corresponding homozygous genotypes. Furthermore, field trial data demonstrated that yields of improved 9311 lines were higher than or similar to that of the control under natural field conditions. These improved versions can be immediately used in hybrid improvement and production. Compared with controls, pyramided lines and hybrids with three genes showed the strongest resistance to BPH, without a yield decrease. © 2012 Society of Chemical Industry.

  5. Marker-assisted introgression of broad-spectrum blast resistance genes into the cultivated MR219 rice variety.

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

    2017-07-01

    The rice cultivar MR219 is famous for its better yield and long and fine grain quality; however, it is susceptible to blast disease. The main objective of this study was to introgress blast resistance genes into MR219 through marker-assisted selection (MAS). The rice cultivar MR219 was used as the recurrent parent, and Pongsu Seribu 1 was used as the donor. Marker-assisted foreground selection was performed using RM6836 and RM8225 to identify plants possessing blast resistance genes. Seventy microsatellite markers were used to estimate recurrent parent genome (RPG) recovery. Our analysis led to the development of 13 improved blast resistant lines with Piz, Pi2 and Pi9 broad-spectrum blast resistance genes and an MR219 genetic background. The RPG recovery of the selected improved lines was up to 97.70% with an average value of 95.98%. Selected improved lines showed a resistance response against the most virulent blast pathogen pathotype, P7.2. The selected improved lines did not express any negative effect on agronomic traits in comparison with MR219. The research findings of this study will be a conducive approach for the application of different molecular techniques that may result in accelerating the development of new disease-resistant rice varieties, which in turn will match rising demand and food security worldwide. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Rheological, physical, and sensory attributes of gluten-free rice cakes containing resistant starch.

    Science.gov (United States)

    Tsatsaragkou, Kleopatra; Papantoniou, Maria; Mandala, Ioanna

    2015-02-01

    In this study the effect of resistant starch (RS) addition on gluten-free cakes from rice flour and tapioca starch physical and sensorial properties was investigated. Increase in RS concentration made cake batters less elastic (drop of G'(ω), G''(ω) values) and thinner (viscosity decreased). Cakes specific volume increased with an increase in RS level and was maximized for 15 g/100 g RS, although porosity values were significantly unaffected by RS content. Crumb grain analysis exhibited a decrease in surface porosity, number of pores and an increase in average pore diameter as RS concentration increased. During storage, cake crumb remained softer in formulations with increasing amounts of RS. Sensory evaluation of cakes demonstrated the acceptance of all formulations, with cake containing 20 g/100 g RS mostly preferred. Gluten-free cakes with improved quality characteristics and high nutritional value can be manufactured by the incorporation of RS. © 2015 Institute of Food Technologists®

  7. Effect of zinc on grain characteristics of draught-resistant rice mutants

    International Nuclear Information System (INIS)

    Abo-Hegazi, A.M.T.; Rofail, N.B.; Eissa, E.A.; Hassan, A.M.

    1996-01-01

    Through the use of Instrumental Neutron Activation Analysis (INAA), zinc concentration was determined in kernels resulted on plants of six drought-resistant rice mutant lines fertilized with zinc sulphate. It was found that zinc fertilization increased zinc residues in the kernels with varying concentrations depending on the line, each line reacted and responded to zinc independently. Zinc content in the kernels ranged from 5.63 to 91.4 ppm in the unfertilized control lines. This range was enlarged due to zinc fertilization of the plants to be from 93.51 to 554.53 ppm. It was also noticed that zinc fertilization increased seed heaviness in varying degrees depending on the line itself. This increase may be due to the increase in kernel thickness rather than in kernel width or length. (author). 26 refs., 3 figs

  8. Differential effectiveness of Serratia plymuthica IC1270-induced systemic resistance against hemibiotrophic and necrotrophic leaf pathogens in rice

    Directory of Open Access Journals (Sweden)

    Höfte Monica M

    2009-01-01

    Full Text Available Abstract Background Induced resistance is a state of enhanced defensive capacity developed by a plant reacting to specific biotic or chemical stimuli. Over the years, several forms of induced resistance have been characterized, including systemic acquired resistance, which is induced upon localized infection by an avirulent necrotizing pathogen, and induced systemic resistance (ISR, which is elicited by selected strains of nonpathogenic rhizobacteria. However, contrary to the relative wealth of information on inducible defense responses in dicotyledoneous plants, our understanding of the molecular mechanisms underlying induced resistance phenomena in cereal crops is still in its infancy. Using a combined cytomolecular and pharmacological approach, we analyzed the host defense mechanisms associated with the establishment of ISR in rice by the rhizobacterium Serratia plymuthica IC1270. Results In a standardized soil-based assay, root treatment with IC1270 rendered foliar tissues more resistant to the hemibiotrophic pathogen Magnaporthe oryzae, causal agent of the devastating rice blast disease. Analysis of the cytological and biochemical alterations associated with restriction of fungal growth in IC1270-induced plants revealed that IC1270 primes rice for enhanced attacker-induced accumulation of reactive oxygen species (ROS and autofluorescent phenolic compounds in and near epidermal cells displaying dense cytoplasmic granulation. Similar, yet more abundant, phenotypes of hypersensitively dying cells in the vicinity of fungal hyphae were evident in a gene-for-gene interaction with an avirulent M. oryzae strain, suggesting that IC1270-inducible ISR and R protein conditioned effector-triggered immunity (ETI target similar defense mechanisms. Yet, this IC1270-inducible ISR response seems to act as a double-edged sword within the rice defense network as induced plants displayed an increased vulnerability to the necrotrophic pathogens Rhizoctonia

  9. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Directory of Open Access Journals (Sweden)

    Hue Thi Nguyen

    2018-01-01

    Full Text Available Bacterial leaf blight of rice (BLB, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F3 5.1.5.1, BC3F3 5.1.5.12, BC3F3 8.5.6.44, BC3F3 9.5.4.1 and BC3F3 9.5.4.23 were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  10. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Institute of Scientific and Technical Information of China (English)

    Hue Thi NGUYEN; Trung Nguyen DINH; Nakano TOSHITSUGU; Liet Van VU; Quang Hong VU; Tan Van MAI; Thu Thi NGUYEN; Lam Duc VU; Tung Thanh NGUYEN; Long Viet NGUYEN; Hien Thu Thi VU; Hue Thi NONG

    2018-01-01

    Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F35.1.5.1, BC3F35.1.5.12, BC3F38.5.6.44, BC3F3 9.5.4.1 and BC3F39.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  11. Mapping and pyramiding of two major genes for resistance to the brown planthopper (Nilaparvata lugens [St?l]) in the rice cultivar ADR52

    OpenAIRE

    Myint, Khin Khin Marlar; Fujita, Daisuke; Matsumura, Masaya; Sonoda, Tomohiro; Yoshimura, Atsushi; Yasui, Hideshi

    2011-01-01

    The brown planthopper (BPH), Nilaparvata lugens (St?l), is one of the most serious and destructive pests of rice, and can be found throughout the rice-growing areas of Asia. To date, more than 24 major BPH-resistance genes have been reported in several Oryza sativa ssp. indica cultivars and wild relatives. Here, we report the genetic basis of the high level of BPH resistance derived from an Indian rice cultivar, ADR52, which was previously identified as resistant to the whitebacked planthoppe...

  12. Effect of Hydrothermal Treatment on the Physicochemical, Rheological, and Oil-Resistant Properties of Rice Flour

    Science.gov (United States)

    Rice flour was thermo-mechanically modified by steam jet-cooking and the physico-chemical and rheological properties of the resulting product were characterized. Then, its performance in frying batters was evaluated as an oil barrier. Compared to native rice flour, the steam jet-cooked rice flour ...

  13. Mechanical properties of a high amylose content corn starch based film, gelatinized at low temperature Propriedades mecânicas de filme a base de amido de milho de alto teor de amilose gelatinizado em baixa temperatura

    Directory of Open Access Journals (Sweden)

    Maria Alejandra Bertuzzi

    2012-09-01

    Full Text Available In the present study, a better knowledge of the influence of plasticizer content, storage relative humidity and film thickness on the mechanical properties of high amylose corn starch based films gelatinized at low temperature, is presented. The mechanical properties, tensile strength and percentage of elongation at break of high amylose corn starch films plasticized with glycerol were evaluated using tension tests. The films exhibited an increase in elongation and a decrease in tensile strength with increasing plasticizer concentration. When the glycerol level was high, some fissures were detected in the dry films, possible due to phase separation (starch-glycerol phenomena. Film crystallinity is related to the reorganization capacity of the polymer chain, and thus the relative film crystallinity should increase with plasticizer content (glycerol and water. The mechanical properties were found to be strongly dependent on the water content due to the hydrophilic nature of starch films. The influence of moisture sorption on tensile strength was similar to that of plasticization with glycerol. The relationship between polymer chain mobility and water content explained this behavior. Elongation suffered a different effect and maximum values were reached at 45% relative humidity. The final drop in elongation was due to a softening of the structure at high relative humidity. The thicker the film the longer the drying time required, leading to greater relative crystallinity due to the corresponding increase in the possibility for chain reorganization. As a consequence, linear increases in tensile strength and elongation were observed with film thickness over the whole range studied (30 to 100 µm.No presente estudo, é apresentado um melhor conhecimento da influência do teor em plastificante, da umidade relativa de armazenamento e da espessura do filme nas propriedades mecânicas do filme baseado em amido de milho de alto conteúdo de amilose

  14. Overexpression of Rice Wall-Associated Kinase 25 (OsWAK25) Alters Resistance to Bacterial and Fungal Pathogens

    Science.gov (United States)

    Harkenrider, Mitch; Sharma, Rita; De Vleesschauwer, David; Tsao, Li; Zhang, Xuting; Chern, Mawsheng; Canlas, Patrick; Zuo, Shimin; Ronald, Pamela C.

    2016-01-01

    Wall-associated kinases comprise a sub-family of receptor-like kinases that function in plant growth and stress responses. Previous studies have shown that the rice wall-associated kinase, OsWAK25, interacts with a diverse set of proteins associated with both biotic and abiotic stress responses. Here, we show that wounding and BTH treatments induce OsWAK25 transcript expression in rice. We generated OsWAK25 overexpression lines and show that these lines exhibit a lesion mimic phenotype and enhanced expression of rice NH1 (NPR1 homolog 1), OsPAL2, PBZ1 and PR10. Furthermore, these lines show resistance to the hemibiotrophic pathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Magnaporthe oryzae, yet display increased susceptibility to necrotrophic fungal pathogens, Rhizoctonia solani and Cochliobolus miyabeanus. PMID:26795719

  15. Molecular Breeding of Rice Restorer Lines and Hybrids for Brown Planthopper (BPH) Resistance Using the Bph14 and Bph15 Genes.

    Science.gov (United States)

    Wang, Hongbo; Ye, Shengtuo; Mou, Tongmin

    2016-12-01

    The development of hybrid rice is a practical approach for increasing rice production. However, the brown planthopper (BPH), Nilaparvata lugens Stål, causes severe yield loss of rice (Oryza sativa L.) and can threaten food security. Therefore, breeding hybrid rice resistant to BPH is the most effective and economical strategy to maintain high and stable production. Fortunately, numerous BPH resistance genes have been identified, and abundant linkage markers are available for molecular marker-assisted selection (MAS) in breeding programs. Hence, we pyramided two BPH resistance genes, Bph14 and Bph15, into a susceptive CMS restorer line Huahui938 and its derived hybrids using MAS to improve the BPH resistance of hybrid rice. Three near-isogenic lines (NILs) with pyramided Bph14 and Bph15 were obtained by molecular marker-assisted backcross (MAB) and phenotypic selection. The genomic components of these NILs were detected using the whole-genome SNP (Single nucleotide polymorphism) array, RICE6K, suggesting that the recurrent parent genome (RPG) recovery of the NILs was 87.88, 87.70 and 86.62 %, respectively. BPH bioassays showed that the improved NILs and their derived hybrids carrying homozygous Bph14 and Bph15 were resistant to BPH. However, the hybrids with heterozygous Bph14 and Bph15 remained susceptible to BPH. The developed NILs showed no significant differences in major agronomic traits and rice qualities compared with the recurrent parent. Moreover, the improved hybrids derived from the NILs exhibited better agronomic performance and rice quality compared with the controls under natural field conditions. This study demonstrates that it is essential to stack Bph14 and Bph15 into both the maternal and paternal parents for developing BPH-resistant hybrid rice varieties. The SNP array with abundant DNA markers is an efficient tool for analyzing the RPG recovery of progenies and can be used to monitor the donor segments in NILs, thus being extremely important

  16. Fine mapping and introgressing qFIS1-2, a major QTL for kernel fissure resistance in rice (Oryza sativa L.)

    Science.gov (United States)

    Rice (Oryza sativa L.) kernel fissuring increases breakage during milling and decreases the value of processed rice. This study employed molecular gene tagging methods to fine-map a fissure resistance (FR) locus in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as transfer this trait to...

  17. Introgression of Blast Resistance Genes (Putative Pi-b and Pi-kh) into Elite Rice Cultivar MR219 through Marker-Assisted Selection

    Science.gov (United States)

    Tanweer, Fatah A.; Rafii, Mohd Y.; Sijam, Kamaruzaman; Rahim, Harun A.; Ahmed, Fahim; Ashkani, Sadegh; Latif, Mohammad A.

    2015-01-01

    Blast is the most common biotic stress leading to the reduction of rice yield in many rice-growing areas of the world, including Malaysia. Improvement of blast resistance of rice varieties cultivated in blast endemic areas is one of the most important objectives of rice breeding programs. In this study, the marker-assisted backcrossing strategy was applied to improve the blast resistance of the most popular Malaysian rice variety MR219 by introgressing blast resistance genes from the Pongsu Seribu 2 variety. Two blast resistance genes, Pi-b and Pi-kh, were pyramided into MR219. Foreground selection coupled with stringent phenotypic selection identified 15 plants homozygous for the Pi-b and Pi-kh genes, and background selection revealed more than 95% genome recovery of MR219 in advanced blast resistant lines. Phenotypic screening against blast disease indicated that advanced homozygous blast resistant lines were strongly resistant against pathotype P7.2 in the blast disease endemic areas. The morphological, yield, grain quality, and yield-contributing characteristics were significantly similar to those of MR219. The newly developed blast resistant improved lines will retain the high adoptability of MR219 by farmers. The present results will also play an important role in sustaining the rice production of Malaysia. PMID:26734013

  18. Development of Elite BPH-Resistant Wide-Spectrum Restorer Lines for Three and Two Line Hybrid Rice.

    Science.gov (United States)

    Fan, Fengfeng; Li, Nengwu; Chen, Yunping; Liu, Xingdan; Sun, Heng; Wang, Jie; He, Guangcun; Zhu, Yingguo; Li, Shaoqing

    2017-01-01

    Hybrid rice has contributed significantly to the world food security. Breeding of elite high-yield, strong-resistant broad-spectrum restorer line is an important strategy for hybrid rice in commercial breeding programs. Here, we developed three elite brown planthopper (BPH)-resistant wide-spectrum restorer lines by pyramiding big-panicle gene Gn8.1 , BPH-resistant genes Bph6 and Bph9 , fertility restorer genes Rf3, Rf4, Rf5 , and Rf6 through molecular marker assisted selection. Resistance analysis revealed that the newly developed restorer lines showed stronger BPH-resistance than any of the single-gene donor parent Luoyang-6 and Luoyang-9. Moreover, the three new restorer lines had broad spectrum recovery capabilities for Honglian CMS, Wild abortive CMS and two-line GMS sterile lines, and higher grain yields than that of the recurrent parent 9,311 under nature field conditions. Importantly, the hybrid crosses also showed good performance for grain yield and BPH-resistance. Thus, the development of elite BPH-resistant wide-spectrum restorer lines has a promising future for breeding of broad spectrum BPH-resistant high-yield varieties.

  19. Ectopic Expression of Hrf1 Enhances Bacterial Resistance via Regulation of Diterpene Phytoalexins, Silicon and Reactive Oxygen Species Burst in Rice

    Science.gov (United States)

    Zhong, Weigong; Yang, Jie; Okada, Kazunori; Yamane, Hisakazu; Zhang, Lei; Wang, Guang; Wang, Dong; Xiao, Shanshan; Chang, Shanshan; Qian, Guoliang; Liu, Fengquan

    2012-01-01

    Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo), Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpinXoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H2O2) concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H2O2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens. PMID:22970151

  20. Ectopic expression of Hrf1 enhances bacterial resistance via regulation of diterpene phytoalexins, silicon and reactive oxygen species burst in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo, Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpin(Xoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H(2O(2 concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM and energy-dispersive X-ray spectrometer (EDS. Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H(2O(2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens.

  1. Molecular dynamics of detoxification and toxin-tolerance genes in brown planthopper (Nilaparvata lugens Stål., Homoptera: Delphacidae) feeding on resistant rice plants.

    Science.gov (United States)

    Yang, Zhifan; Zhang, Futie; He, Qing; He, Guangcun

    2005-06-01

    To investigate the molecular response of brown planthopper, Nilaparvata lugens (BPH) to BPH-resistant rice plants, we isolated cDNA fragments of the genes encoding for carboxylesterase (CAR), trypsin (TRY), cytochrome P450 monooxygenase (P450), NADH-quinone oxidoreductase (NQO), acetylcholinesterase (ACE), and Glutathione S-transferase (GST). Expression profiles of the genes were monitored on fourth instar nymphs feeding on rice varieties with different resistance levels. Northern blot hybridization showed that, compared with BPH reared on susceptible rice TN1, expression of the genes for P450 and CAR was apparently up-regulated and TRY mRNA decreased in BPH feeding on a highly resistant rice line B5 and a moderately resistant rice variety MH63, respectively. Two transcripts of GST increased in BPH feeding on B5; but in BPH feeding on MH63, this gene was inducible and its expression reached a maximum level at 24 h, and then decreased slightly. The expression of NQO gene was enhanced in BPH on B5 plants but showed a constant expression in BPH on MH63 plants. No difference in ACE gene expression among BPH on different rice plants was detected by the RT-PCR method. The results suggest these genes may play important roles in the defense response of BPH to resistant rice.

  2. An EAR-motif-containing ERF transcription factor affects herbivore-induced signaling, defense and resistance in rice.

    Science.gov (United States)

    Lu, Jing; Ju, Hongping; Zhou, Guoxin; Zhu, Chuanshu; Erb, Matthias; Wang, Xiaopeng; Wang, Peng; Lou, Yonggen

    2011-11-01

    Ethylene responsive factors (ERFs) are a large family of plant-specific transcription factors that are involved in the regulation of plant development and stress responses. However, little to nothing is known about their role in herbivore-induced defense. We discovered a nucleus-localized ERF gene in rice (Oryza sativa), OsERF3, that was rapidly up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis. Antisense and over-expression of OsERF3 revealed that it positively affects transcript levels of two mitogen-activated protein kinases (MAPKs) and two WRKY genes as well as concentrations of jasmonate (JA), salicylate (SA) and the activity of trypsin protease inhibitors (TrypPIs). OsERF3 was also found to mediate the resistance of rice to SSB. On the other hand, OsERF3 was slightly suppressed by the rice brown planthopper (BPH) Nilaparvata lugens (Stål) and increased susceptibility to this piercing sucking insect, possibly by suppressing H(2)O(2) biosynthesis. We propose that OsERF3 affects early components of herbivore-induced defense responses by suppressing MAPK repressors and modulating JA, SA, ethylene and H(2)O(2) pathways as well as plant resistance. Our results also illustrate that OsERF3 acts as a central switch that gears the plant's metabolism towards an appropriate response to chewing or piercing/sucking insects. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  3. Nucleotide diversity analysis of three major bacterial blight resistance genes in rice.

    Directory of Open Access Journals (Sweden)

    Waikhom Bimolata

    Full Text Available Nucleotide sequence polymorphisms among R gene alleles influence the process of co-evolutionary interaction between host and pathogen by shaping the response of host plants towards invading pathogens. Here, we present the DNA sequence polymorphisms and diversities present among natural alleles of three rice bacterial blight resistance genes, Xa21, Xa26 and xa5. The diversity was examined across different wild relatives and cultivars of Oryza species. Functional significance of selected alleles was evaluated through semi-quantitative reverse transcription polymerase chain reaction and real time PCR. The greatest nucleotide diversity and singleton variable sites (SVS were present in Xa26 (π = 0.01958; SVS = 182 followed by xa5 and Xa21 alleles. The highest frequency of single nucleotide polymorphisms were observed in Xa21 alleles and least in xa5. Transition bias was observed in all the genes and 'G' to 'A' transitions were more favored than other form of transitions. Neutrality tests failed to show the presence of selection at these loci, though negative Tajima's D values indicate the presence of a rare form of polymorphisms. At the interspecies level, O. nivara exhibited more diversity than O. sativa. We have also identified two nearly identical resistant alleles of xa5 and two sequentially identical alleles of Xa21. The alleles of xa5 showed basal levels of expression while Xa21 alleles were functionally not expressed.

  4. A rare sugar, d-allose, confers resistance to rice bacterial blight with upregulation of defense-related genes in Oryza sativa.

    Science.gov (United States)

    Kano, Akihito; Gomi, Kenji; Yamasaki-Kokudo, Yumiko; Satoh, Masaru; Fukumoto, Takeshi; Ohtani, Kouhei; Tajima, Shigeyuki; Izumori, Ken; Tanaka, Keiji; Ishida, Yutaka; Tada, Yasuomi; Nishizawa, Yoko; Akimitsu, Kazuya

    2010-01-01

    We investigated responses of rice plant to three rare sugars, d-altrose, d-sorbose, and d-allose, due to establishment of mass production methods for these rare sugars. Root growth and shoot growth were significantly inhibited by d-allose but not by the other rare sugars. A large-scale gene expression analysis using a rice microarray revealed that d-allose treatment causes a high upregulation of many defense-related, pathogenesis-related (PR) protein genes in rice. The PR protein genes were not upregulated by other rare sugars. Furthermore, d-allose treatment of rice plants conferred limited resistance of the rice against the pathogen Xanthomonas oryzae pv. oryzae but the other tested sugars did not. These results indicate that d-allose has a growth inhibitory effect but might prove to be a candidate elicitor for reducing disease development in rice.

  5. Molecular mapping of qBK1 WD , a major QTL for bakanae disease resistance in rice.

    Science.gov (United States)

    Lee, Sais-Beul; Hur, Yeon-Jae; Cho, Jun-Hyeon; Lee, Jong-Hee; Kim, Tae-Heon; Cho, Soo-Min; Song, You-Chun; Seo, Young-Su; Lee, Jungkwan; Kim, Tae-Sung; Park, Yong-Jin; Oh, Myung-Kyu; Park, Dong-Soo

    2018-01-10

    Bakanae or foot rot disease is a prominent disease of rice caused by Gibberella fujikuroi. This disease may infect rice plants from the pre-emergence stage to the mature stage. In recent years, raising rice seedlings in seed boxes for mechanical transplanting has increased the incidence of many seedling diseases; only a few rice varieties have been reported to exhibit resistance to bakanae disease. In this study, we attempted to identify quantitative trait loci (QTLs) conferring bakanae disease resistance from the highly resistant japonica variety Wonseadaesoo. A primary QTL study using the genotypes/phenotypes of the recombinant inbred lines (RILs) indicated that the locus qBK1 WD conferring resistance to bakanae disease from Wonseadaesoo was located in a 1.59 Mb interval delimited on the physical map between chr01_13542347 (13.54 Mb) and chr01_15132528 (15.13 Mb). The log of odds (LOD) score of qBK1 WD was 8.29, accounting for 20.2% of the total phenotypic variation. We further identified a gene pyramiding effect of two QTLs, qBK WD and previously developed qBK1. The mean proportion of healthy plant for 31 F 4 RILs that had no resistance genes was 35.3%, which was similar to that of the susceptible check variety Ilpum. The proportion of healthy plants for the lines with only qBK WD or qBK1 was 66.1% and 55.5%, respectively, which was significantly higher than that of the lines without resistance genes and that of Ilpum. The mean proportion of the healthy plant for 15 F 4 RILs harboring both qBK WD and qBK1 was 80.2%, which was significantly higher than that of the lines with only qBK WD or qBK1. Introducing qBK WD or pyramiding the QTLs qBK WD and qBK1 could provide effective tools for breeding rice with bakanae disease resistance. To our knowledge, this is the first report on a gene pyramiding effect that provides higher resistance against bakanae disease.

  6. A study on compatibilities on transgenic herbicide-resistant rice with wild relatives by using autoradiography of 32P labeled pollen

    International Nuclear Information System (INIS)

    Liu Linli; Qiang Sheng; Song Xiaoling

    2004-01-01

    To evaluate the possibility of gene flow through observation of the sexual compatibilities of transgenic herbicide-resistant rice with wild relative by using isotope tracer to label pollen grains, the experiments on radioactivity, tracer mode, autoradiography film and time were conducted. Better procedure was to label pollen grains of transgenic herbicide-resistant rice by culturing the rice in a 1.48 x 10 7 Bq/L 32 P nutrient liquid, to pollinate the labelled pollen grains on the stigmas of barnyard grass (Echinochloa crusgalli var. mitis), Oryza officinalis and weedy rice (Oryza sativa) respectively, and then 3 hour later, to fix these pistils on a piece of glass plate and cover the film of Luck 400 on it for autoradiography. The autoradiographs show that the tube of the transgenic rice's pollens cannot penetrate the stigma of barnyard grass and arrive at embryo sacs to fertilize, so that the possibility of gene flow between them is the lowest; the tube of the labelled pollens can penetrate the stigma of O officinalis and enter the style but can not arrive at embryo sacs to fertilize, so the possibility of gene flow between them is relatively low; and the pollen tube can arrive at the embryo sacs of the weedy rice, so that the possibility of gene flow is relatively high from transgenic herbicide-resistant rice to weedy rice. (authors)

  7. Intercellular production of tamavidin 1, a biotin-binding protein from Tamogitake mushroom, confers resistance to the blast fungus Magnaporthe oryzae in transgenic rice.

    Science.gov (United States)

    Takakura, Yoshimitsu; Oka, Naomi; Suzuki, Junko; Tsukamoto, Hiroshi; Ishida, Yuji

    2012-05-01

    The blast fungus Magnaporthe oryzae, one of the most devastating rice pathogens in the world, shows biotin-dependent growth. We have developed a strategy for creating disease resistance to M. oryzae whereby intercellular production of tamavidin 1, a biotin-binding protein from Pleurotus cornucopiae occurs in transgenic rice plants. The gene that encodes tamavidin 1, fused to the sequence for a secretion signal peptide derived from rice chitinase gene, was connected to the Cauliflower mosaic virus 35S promoter, and the resultant construct was introduced into rice. The tamavidin 1 was accumulated at levels of 0.1-0.2% of total soluble leaf proteins in the transgenic rice and it was localized in the intercellular space of rice leaves. The tamavidin 1 purified from the transgenic rice was active, it bound to biotin and inhibited in vitro growth of M. oryzae by causing biotin deficiency. The transgenic rice plants showed a significant resistance to M. oryzae. This study shows the possibility of a new strategy to engineer disease resistance in higher plants by taking advantage of a pathogen's auxotrophy.

  8. Evaluation of resistant starch, glycemic index and fortificants content of premix rice coated with various concentrations and types of edible coating materials

    Science.gov (United States)

    Yulianto, W. A.; Susiati, A. M.; Adhini, H. A. N.

    2018-01-01

    The incidence of diabetes in Indonesia has been increasing year by year. Diets with a low glycemic index and high resistant starch foods can assist diabetics in controlling their blood glucose levels. Diabetics are known to have micro-nutrient deficiencies of chromium, magnesium and vitamin D that can be overcome by consuming parboiled rice fortified by use of a coating method. The fortification of parboiled rice (premix rice) can be achieved by coating with HPMC (hydroxypropyl methyl cellulose), MC (methyl cellulose), CMC (carboxyl methyl cellulose), gum arabic and rice starch. This research aimed to evaluate the levels of resistant starch, glycemic index and fortificants of premix rice coated with different concentrations and types of edible coating materials. This research used completely randomized design, with treatments to the concentrations and the types of edible coating (HPMC, CMC, MC, gum arabic and rice starch). The concentrations of edible coating were 0.15%, 0.2% and 0.25% for cellulose derivative coatings; 25%, 30%, 35% for gum arabic and 2%, 3.5% and 5% for rice starch. This research shows that fortified premix rice coated with various concentrations and types of edible coating materials is high in resistant starch and has a low glycemic index. The coating treatment affects the levels of magnesium and vitamin D, but does not affect the levels of chromium in parboiled rice. The premix rice with a low glycemic index and high nutrient content (chromium, magnesium and vitamin D) was premix rice coated by CMC 0.25% and HPMC 0.25% with glycemic indeces of 39.34 and 38.50, respectively.

  9. Development of 25 near-isogenic lines (NILs) with ten BPH resistance genes in rice (Oryza sativa L.): production, resistance spectrum, and molecular analysis.

    Science.gov (United States)

    Jena, Kshirod K; Hechanova, Sherry Lou; Verdeprado, Holden; Prahalada, G D; Kim, Sung-Ryul

    2017-11-01

    A first set of 25 NILs carrying ten BPH resistance genes and their pyramids was developed in the background of indica variety IR24 for insect resistance breeding in rice. Brown planthopper (Nilaparvata lugens Stal.) is one of the most destructive insect pests in rice. Development of near-isogenic lines (NILs) is an important strategy for genetic analysis of brown planthopper (BPH) resistance (R) genes and their deployment against diverse BPH populations. A set of 25 NILs with 9 single R genes and 16 multiple R gene combinations consisting of 11 two-gene pyramids and 5 three-gene pyramids in the genetic background of the susceptible indica rice cultivar IR24 was developed through marker-assisted selection. The linked DNA markers for each of the R genes were used for foreground selection and confirming the introgressed regions of the BPH R genes. Modified seed box screening and feeding rate of BPH were used to evaluate the spectrum of resistance. BPH reaction of each of the NILs carrying different single genes was variable at the antibiosis level with the four BPH populations of the Philippines. The NILs with two- to three-pyramided genes showed a stronger level of antibiosis (49.3-99.0%) against BPH populations compared with NILs with a single R gene NILs (42.0-83.5%) and IR24 (10.0%). Background genotyping by high-density SNPs markers revealed that most of the chromosome regions of the NILs (BC 3 F 5 ) had IR24 genome recovery of 82.0-94.2%. Six major agronomic data of the NILs showed a phenotypically comparable agronomic performance with IR24. These newly developed NILs will be useful as new genetic resources for BPH resistance breeding and are valuable sources of genes in monitoring against the emerging BPH biotypes in different rice-growing countries.

  10. Tagging of blast resistance gene(s) to DNA markers and marker-assisted selection (MAS) in rice improvement

    International Nuclear Information System (INIS)

    Zhuang, J.Y.; Lu, J.; Qian, H.R.; Lin, H.X.; Zheng, K.L.

    1998-01-01

    This paper reports progress made on the tagging of blast resistance gene(s) to DNA markers and on the initiation of marker-assisted selection (MAS) for blast resistance in rice improvement. A pair of near isogenic lines, K8OR and K79S, were developed using a Chinese landrace Hong-jiao-zhan as the resistance donor. Ten putatively positive markers were identified by screening 177 mapped DNA markers. Using the F 2 population of 143 plants and the derived F 3 lines, three Restriction Fragment Length Polymorphism (RFLP) markers (RG81, RG869 and RZ397) on chromosome 12 of rice were identified to be closely linked to the blast resistance gene Pi-12(t). The genetic distance between Pi-12(t) and the closest marker RG869 was 5.1 cM. By employing the bulk segregant analysis (BSA) procedure, six of 199 arbitrary primers were found to produce positive Randomly Amplified Polymorphic DNA (RAPD) bands. Tight linkage between Pi-12(t) and three RAPD bands, each from a different primer, was confirmed after amplification of DNA of all F 2 individuals. Two fragments were cloned and sequenced, and two sequence characterised amplified re-ion (SCAR) markers were established. In two other F 3 populations, Xian-feng I/Tetep and Xian-feng, 1/Hong-jiao-zhan, the blast resistance was found to be controlled by interactions of two or more genes. One resistance gene was located in the vicinity of RG81 in both populations. Work to identify other gene(s) is currently under way. Marker assisted selection for blast resistance was initiated. Crosses were made between elite varieties and blast resistance donors to develop populations for DNA marker-assisted selection of blast resistance. In addition, 48 varieties widely used in current rice breeding programs were provided by rice breeders. DNA marker-based polymorphism among, these varieties and resistance donors were analysed to produce a database for future MAS program. (author)

  11. Resistência do arroz de terras altas ao alumínio Aluminum resistance of upland rice

    Directory of Open Access Journals (Sweden)

    Cleber M. Guimarães

    2006-12-01

    Full Text Available Objetivou-se, com este trabalho, identificar indicadores de resistência à toxicidade de alumínio em arroz de terras altas e linhagens com baixa susceptibilidade a esta toxicidade. Avaliaram-se 48 linhagens de arroz em solução nutritiva e dois níveis de estresse de alumínio: 0 e 40 mg dm-3 de Al; após 21 dias de teste, estimaram-se a massa da matéria seca das raízes e do dossel, o comprimento máximo das raízes e a altura das plantas e, também, índices de susceptibilidade à toxicidade de alumínio. Verificou-se que todos os indicadores de susceptibilidade ao alumínio, exceto aqueles relacionados à variabilidade do pH, se correlacionaram significativamente. O índice de susceptibilidade do crescimento radicular (S Rcm por se considerar, no seu cálculo, o crescimento radicular com e sem estresse de Al e a pressão de estresse de Al em que as linhagens foram avaliadas, constitui-se em importante parâmetro a ser usado na seleção para resistência à toxicidade ao alumínio. Conforme a distribuição das linhagens em quartis, delimitados pelo comprimento radicular superior a 47 cm e pelo SRcm menor que 0,92, selecionou-se o grupo de linhagens, CNA4120, CNA4164 e CNA1383, que apresenta raízes bem desenvolvidas, tanto na ausência como na presença de alumínio.The objective of this work was to identify indicators of resistance of aluminum toxicity in upland rice as well as lines with low susceptibility to this toxicity. Fifty one rice lines were evaluated in greenhouse, in nutrient solution, under two levels: 0 and 40 mg dm-3 of Al. Data of dry weight of roots and aerial parts, length of roots and plant height were obtained 21 days later. Also, the index of susceptibility to aluminum toxicity was calculated. The results showed significant correlation between all indicators with each other, except to those related to pH variability. Since root length susceptibility index (S Rcm was calculated taking into consideration the root

  12. A built-in mechanism to mitigate the spread of insect-resistance and herbicide-tolerance transgenes into weedy rice populations.

    Directory of Open Access Journals (Sweden)

    Chengyi Liu

    Full Text Available BACKGROUND: The major challenge of cultivating genetically modified (GM rice (Oryza sativa at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea. The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. METHODOLOGY/PRINCIPAL FINDINGS: An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m(2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F(2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13 and two weedy rice strains (PI-63 and PI-1401. CONCLUSIONS/SIGNIFICANCE: Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations.

  13. A Built-In Mechanism to Mitigate the Spread of Insect-Resistance and Herbicide-Tolerance Transgenes into Weedy Rice Populations

    Science.gov (United States)

    Liu, Chengyi; Li, Jingjing; Gao, Jianhua; Shen, Zhicheng; Lu, Bao-Rong; Lin, Chaoyang

    2012-01-01

    Background The major challenge of cultivating genetically modified (GM) rice (Oryza sativa) at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea). The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. Methodology/Principal Findings An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13) and two weedy rice strains (PI-63 and PI-1401). Conclusions/Significance Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations. PMID:22359609

  14. In silico Allergenicity Study of Insect resistant genetically Modified Rice (Oryza sativa L. for assessment of biosafety

    Directory of Open Access Journals (Sweden)

    S.K. Das

    2017-12-01

    Full Text Available India is one of the world's largest producers of rice (Oryza sativa, accounting for 20% of all world rice production. However, lepidopteran pests severely impact the harvest of rice, which leads to environmental pollution and increase production cost. Alternatively, genetic engineering methods may be used to prevent rice pests and increase production of rice in a safe and environmentally friendly manner. Bacillus thuringiensis (Bt genes have been widely used to generate genetically modified (GM crops because the expressed cry1Ab protein confers resistance to lepidopteron pests. The proteins expressed by these genes may lead to food safety problems. Thus, safety evaluations are necessary prior to commercialization. Bioinformatics analysis for allergenicity assessment of cry1Ab protein is performed using different allergen databases viz. FARRP SDAP, Allergome, and Algpred to identify any potential sequence matches to allergen proteins that might indicate allergenic cross-reactivity with the query sequence. A full FASTA search was performed to identify highly similar proteins. However; the full length search cannot identify discontinuous or conformational epitopes that depend upon the tertiary structure of the protein.So every possible contiguous 80-amino acid sequence of each query protein was searched for determining the similarity. The proteins sequence can be searched using FASTA/BLAST for broad homology to known allergens to identify any short sequence that might represent an allergenic epitope. The domains in the Cry protein sequences were searched using Interproscan for potential similarity at the domain level. The results showed neither significant alignment nor similarity of cry1Ab protein at full sequence, domain, and epitope level with any of the known allergen proteins in the full sequence matching. Matching the 80 amino acid and matching of 8 amino acids showed no similarity to determine the epitope potential. From literature survey

  15. Micro-aerobics: when rice plants lose their resistance against oxygen

    International Nuclear Information System (INIS)

    Reuss, J; Harren, F J M

    2008-01-01

    Photoacoustic determination of ethane, ethanol and acetaldehyde releases from 14 d old rice seedlings leads to the conclusion that rice seedlings start suffering significant lipid peroxidation under micro-aerobic conditions. To produce micro-aerobic conditions in otherwise normal atmospheres, the oxygen concentration has been reduced to a value between 0.3 and 0.05% (v/v). The defense of the rice seedlings against oxygenic radicals becomes insufficient under these almost anaerobic conditions. The findings presented here are relevant for the clarification of what causes non-survival of rice seedlings under prolonged submergence.

  16. Herbivore-induced callose deposition on the sieve plates of rice: an important mechanism for host resistance.

    Science.gov (United States)

    Hao, Peiying; Liu, Caixiang; Wang, Yuanyuan; Chen, Rongzhi; Tang, Ming; Du, Bo; Zhu, Lili; He, Guangcun

    2008-04-01

    The brown planthopper (Nilaparvata lugens Stål; BPH) is a specialist herbivore on rice (Oryza sativa) that ingests phloem sap from the plant through its stylet mouthparts. Electronic penetration graphs revealed that BPH insects spent more time wandering over plants carrying the resistance genes Bph14 and Bph15, but less time ingesting phloem than they did on susceptible plants. They also showed that their feeding was frequently interrupted. Tests with [(14)C]sucrose showed that insects ingested much less phloem sap from the resistant than the susceptible plants. BPH feeding up-regulated callose synthase genes and induced callose deposition in the sieve tubes at the point where the stylet was inserted. The compact callose remained intact in the resistant plants, but genes encoding beta-1,3-glucanases were activated, causing unplugging of the sieve tube occlusions in susceptible plants. Continuing ingestion led to a remarkable reduction in the susceptible plants' sucrose content and activation of the RAmy3D gene, leading to starch hydrolysis and ultimately carbohydrate deprivation in the plants. Our results demonstrate that BPH feeding induces the deposition of callose on sieve plates in rice and that this is an important defense mechanism that prevents insects from ingesting phloem sap. In response, however, the BPH can unplug sieve tube occlusions by activating beta-1,3-glucanase genes in rice plants.

  17. Effects of nitrogen on egg-laying inhibition and ovicidal response in planthopper-resistant rice varieties.

    Science.gov (United States)

    Horgan, Finbarr G; Srinivasan, Thanga Suja; Naik, Bhaskar S; Ramal, Angelee Fame; Bernal, Carmencita C; Almazan, Maria Liberty P

    2016-11-01

    A series of experiments was set up to examine the effects of nitrogen on rice ( Oryza sativa L.) resistance against Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth). Egg laying by N. lugens was reduced on the indica variety IR60. Nymph biomass ( N. lugens and S. furcifera ) was also lower on IR60: this was associated with low honeydew production and a high proportion of xylem-derived honeydew in N. lugens but not in S. furcifera . Nitrogen increased egg-laying by S. furcifera and increased N. lugens nymph biomass on all varieties tested. Oviposition and egg mortality in both planthopper species were examined on plants at 15, 30 and 45 days after sowing (DAS). Sogatella furcifera laid more eggs on plants at 15 DAS, but laid few eggs during darkness; N. lugens continued to lay eggs on older rice plants (30 DAS) and during darkness. Egg mortality was high on cv. Asiminori, highest at 45 DAS, and higher for S. furcifera than for N. lugens . Mortality of S. furcifera eggs was associated with lesions around the egg clusters. These were more common around clusters laid during the day and suggested induction by Asiminori of an ovicidal response. Egg mortality declined under higher soil nitrogen levels. Results are discussed in the light of improving rice resistance against planthoppers and reducing rates of planthopper adaptation to resistance genes.

  18. A new gene, developed through mutagenesis with thermal neutrons, for resistance of rice to bacterial leaf blight

    International Nuclear Information System (INIS)

    Nakai, H.; Shimozawa, H.; Saito, M.

    1992-01-01

    Dry seed lots of a rice variety, Harebare, susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons with and without pre-treatment of the seeds by boron-enrichment, gamma-rays and nitroso-methyl-urea (NMU). The selections were made on M 2 -M 3 materials by inoculation of Japanese BLB race III, with the result that several BLB resistant mutants to race III and the other differential races could be obtained. Mutagenic efficiency of thermal neutrons to the seeds without boron-enrichment for induction of BLB resistant mutants was found to be significantly higher than that of the other mutagens. Four mutant lines of all the selected ones were analyzed for genes for BLB resistance through cross tests between the mutants and the original variety. Harebare, indicating that the resistance in the mutants was conditioned by single recessive gene(s). The mutant designated 86M95 was especially noted for its gene conferring complete (or durable) resistance to multiple BLB races. The 86M95 mutant or the gene may be of practical value for breeding of rice for BLB resistance. (author)

  19. The identification of candidate rice genes that confer resistance to the brown planthopper (Nilaparvata lugens) through representational difference analysis.

    Science.gov (United States)

    Park, Dong-Soo; Lee, Sang-Kyu; Lee, Jong-Hee; Song, Min-Young; Song, Song-Yi; Kwak, Do-Yeon; Yeo, Un-Sang; Jeon, Nam-Soo; Park, Soo-Kwon; Yi, Gihwan; Song, You-Chun; Nam, Min-Hee; Ku, Yeon-Chung; Jeon, Jong-Seong

    2007-08-01

    The development of rice varieties (Oryza sativa L.) that are resistant to the brown planthopper (BPH; Nilaparvata lugens Stål) is an important objective in current breeding programs. In this study, we generated 132 BC(5)F(5) near-isogenic rice lines (NILs) by five backcrosses of Samgangbyeo, a BPH resistant indica variety carrying the Bph1 locus, with Nagdongbyeo, a BPH susceptible japonica variety. To identify genes that confer BPH resistance, we employed representational difference analysis (RDA) to detect transcripts that were exclusively expressed in one of our BPH resistant NIL, SNBC61, during insect feeding. The chromosomal mapping of the RDA clones that we subsequently isolated revealed that they are located in close proximity either to known quantitative trait loci or to an introgressed SSR marker from the BPH resistant donor parent Samgangbyeo. Genomic DNA gel-blot analysis further revealed that loci of all RDA clones in SNBC61 correspond to the alleles of Samgangbyeo. Most of the RDA clones were found to be exclusively expressed in SNBC61 and could be assigned to functional groups involved in plant defense. These RDA clones therefore represent candidate defense genes for BPH resistance.

  20. Contrasting effects of ethylene biosynthesis on induced plant resistance against a chewing and a piercing-sucking herbivore in rice.

    Science.gov (United States)

    Lu, Jing; Li, Jiancai; Ju, Hongping; Liu, Xiaoli; Erb, Matthias; Wang, Xia; Lou, Yonggen

    2014-11-01

    Ethylene is a stress hormone with contrasting effects on herbivore resistance. However, it remains unknown whether these differences are plant- or herbivore-specific. We cloned a rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, OsACS2, whose transcripts were rapidly up-regulated in response to mechanical wounding and infestation by two important pests: the striped stem borer (SSB) Chilo suppressalis and the brown planthopper (BPH) Nilaparvata lugens. Antisense expression of OsACS2 (as-acs) reduced elicited ethylene emission, SSB-elicited trypsin protease inhibitor (TrypPI) activity, SSB-induced volatile release, and SSB resistance. Exogenous application of ACC restored TrypPI activity and SSB resistance. In contrast to SSB, BPH infestation increased volatile emission in as-acs lines. Accordingly, BPH preferred to feed and oviposit on wild-type (WT) plants--an effect that could be attributed to two repellent volatiles, 2-heptanone and 2-heptanol, that were emitted in higher amounts by as-acs plants. BPH honeydew excretion was reduced and natural enemy attraction was enhanced in as-acs lines, resulting in higher overall resistance to BPH. These results demonstrate that ethylene signaling has contrasting, herbivore-specific effects on rice defense responses and resistance against a chewing and a piercing-sucking insect, and may mediate resistance trade-offs between herbivores of different feeding guilds in rice. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  1. Categories and inheritance of resistance to Nilaparvata lugens (Hemiptera: Delphacidae) in mutants of indica rice 'IR64'.

    Science.gov (United States)

    Sangha, Jatinder Singh; Chen, Yolanda H; Palchamy, Kadirvel; Jahn, Gary C; Maheswaran, M; Adalla, Candida B; Leung, Hei

    2008-04-01

    Varietal mutants can be useful for developing durable resistance, understanding categories of resistance, and identifying candidate genes involved in defense responses. We used mutants of rice 'IR64' to isolate new sources of resistance to the planthopper Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). We compared two mutants that showed a gain and loss of resistance to N. lugens, to determine the categories of resistance to this pest. Under choice tests, female planthoppers avoided settling and laid fewer eggs on the resistant mutant 'D518' than on the susceptible mutant D1131, susceptible check 'TN1', and wild-type IR64, indicating that antixenosis was the resistance category. Similarly, under no-choice conditions, planthoppers laid 29% fewer eggs in D518 than in IR64, but they oviposited more in 'D1131' and TN1. Honeydew excretion was greater on D1131 seedlings but slightly lower on D518 than on IR64. Nymphal survival and adult female weight did not differ among rice cultivars. D518 showed higher tolerance of N. lugens infestations than IR64. Genetic analysis of the F1, F2, and F3 populations derived from D518 x IR64 revealed that resistance in D518 is dominant and controlled by a single gene. Despite the variation in resistance to N. lugens, both mutants and IR64 performed similarly in the field. The mutant D518 is a new source of durable resistance to N. lugens, mainly due to enhanced antixenosis to female hoppers for settling and oviposition.

  2. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Ga Young Jung

    2016-08-01

    Full Text Available ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1 is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus.

  3. Genome-Wide Distribution, Organisation and Functional Characterization of Disease Resistance and Defence Response Genes across Rice Species

    Science.gov (United States)

    Singh, Sangeeta; Chand, Suresh; Singh, N. K.; Sharma, Tilak Raj

    2015-01-01

    The resistance (R) genes and defense response (DR) genes have become very important resources for the development of disease resistant cultivars. In the present investigation, genome-wide identification, expression, phylogenetic and synteny analysis was done for R and DR-genes across three species of rice viz: Oryza sativa ssp indica cv 93-11, Oryza sativa ssp japonica and wild rice species, Oryza brachyantha. We used the in silico approach to identify and map 786 R -genes and 167 DR-genes, 672 R-genes and 142 DR-genes, 251 R-genes and 86 DR-genes in the japonica, indica and O. brachyanth a genomes, respectively. Our analysis showed that 60.5% and 55.6% of the R-genes are tandemly repeated within clusters and distributed over all the rice chromosomes in indica and japonica genomes, respectively. The phylogenetic analysis along with motif distribution shows high degree of conservation of R- and DR-genes in clusters. In silico expression analysis of R-genes and DR-genes showed more than 85% were expressed genes showing corresponding EST matches in the databases. This study gave special emphasis on mechanisms of gene evolution and duplication for R and DR genes across species. Analysis of paralogs across rice species indicated 17% and 4.38% R-genes, 29% and 11.63% DR-genes duplication in indica and Oryza brachyantha, as compared to 20% and 26% duplication of R-genes and DR-genes in japonica respectively. We found that during the course of duplication only 9.5% of R- and DR-genes changed their function and rest of the genes have maintained their identity. Syntenic relationship across three genomes inferred that more orthology is shared between indica and japonica genomes as compared to brachyantha genome. Genome wide identification of R-genes and DR-genes in the rice genome will help in allele mining and functional validation of these genes, and to understand molecular mechanism of disease resistance and their evolution in rice and related species. PMID:25902056

  4. Genetic and biochemical basis of Gall Midge resistance in some cultivars of Indica Rice. Final report for the period 1 October 1980 - 30 November 1986

    International Nuclear Information System (INIS)

    Reddy, G.M.

    1986-01-01

    The stability of high productivity of modern rice varieties is greatly affected by insect pests. Rice gall midge is a serious insect pest of rice that is prevalent in several south eastern asian countries. Gall midge resistance has been mainly attributed to antibiosis. No progress has so far been made in identifying the exact biochemical nature of resistance. In Indica subspecies the understanding of chemical nature of disease would be helpful in the control of the disease and also in breeding programme aimed at developing resistance varieties. Studies were undertaken to establish the biochemical basis of resistance. Biochemical characterization of resistant and susceptible varieties were carried out. The parameters considered were: total sugar and reducing sugar content, total phenol content, amino acid profile, post infectional changes in sugar and phenol, isozyme studies. 2 figs, 6 tabs

  5. Genetic and biochemical basis of Gall Midge resistance in some cultivars of Indica Rice. Final report for the period 1 October 1980 - 30 November 1986

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, G M [Osmania Univ., Hyderabad (India). Dept. of Genetics

    1987-12-31

    The stability of high productivity of modern rice varieties is greatly affected by insect pests. Rice gall midge is a serious insect pest of rice that is prevalent in several south eastern asian countries. Gall midge resistance has been mainly attributed to antibiosis. No progress has so far been made in identifying the exact biochemical nature of resistance. In Indica subspecies the understanding of chemical nature of disease would be helpful in the control of the disease and also in breeding programme aimed at developing resistance varieties. Studies were undertaken to establish the biochemical basis of resistance. Biochemical characterization of resistant and susceptible varieties were carried out. The parameters considered were: total sugar and reducing sugar content, total phenol content, amino acid profile, post infectional changes in sugar and phenol, isozyme studies. 2 figs, 6 tabs.

  6. Expression of hybrid fusion protein (Cry1Ac::ASAL) in transgenic rice plants imparts resistance against multiple insect pests.

    Science.gov (United States)

    Boddupally, Dayakar; Tamirisa, Srinath; Gundra, Sivakrishna Rao; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

    2018-05-31

    To evolve rice varieties resistant to different groups of insect pests a fusion gene, comprising DI and DII domains of Bt Cry1Ac and carbohydrate binding domain of garlic lectin (ASAL), was constructed. Transgenic rice lines were generated and evaluated to assess the efficacy of Cry1Ac::ASAL fusion protein against three major pests, viz., yellow stem borer (YSB), leaf folder (LF) and brown planthopper (BPH). Molecular analyses of transgenic plants revealed stable integration and expression of the fusion gene. In planta insect bioassays on transgenics disclosed enhanced levels of resistance compared to the control plants. High insect mortality of YSB, LF and BPH was observed on transgenics compared to that of control plants. Furthermore, honeydew assays revealed significant decreases in the feeding ability of BPH on transgenic plants as compared to the controls. Ligand blot analysis, using BPH insects fed on cry1Ac::asal transgenic rice plants, revealed a modified receptor protein-binding pattern owing to its ability to bind to additional receptors in insects. The overall results authenticate that Cry1Ac::ASAL protein is endowed with remarkable entomotoxic effects against major lepidopteran and hemipteran insects. As such, the fusion gene appears promising and can be introduced into various other crops to control multiple insect pests.

  7. RNA-Seq analysis reveals insight into enhanced rice Xa7-mediated bacterial blight resistance at high temperature.

    Directory of Open Access Journals (Sweden)

    Stephen P Cohen

    Full Text Available Plant disease is a major challenge to agriculture worldwide, and it is exacerbated by abiotic environmental factors. During some plant-pathogen interactions, heat stress allows pathogens to overcome host resistance, a phenomenon which could severely impact crop productivity considering the global warming trends associated with climate change. Despite the importance of this phenomenon, little is known about the underlying molecular mechanisms. To better understand host plant responses during simultaneous heat and pathogen stress, we conducted a transcriptomics experiment for rice plants (cultivar IRBB61 containing Xa7, a bacterial blight disease resistance (R gene, that were infected with Xanthomonas oryzae, the bacterial blight pathogen of rice, during high temperature stress. Xa7-mediated resistance is unusual relative to resistance mediated by other R genes in that it functions better at high temperatures. Using RNA-Seq technology, we identified 8,499 differentially expressed genes as temperature responsive in rice cultivar IRBB61 experiencing susceptible and resistant interactions across three time points. Notably, genes in the plant hormone abscisic acid biosynthesis and response pathways were up-regulated by high temperature in both mock-treated plants and plants experiencing a susceptible interaction and were suppressed by high temperature in plants exhibiting Xa7-mediated resistance. Genes responsive to salicylic acid, an important plant hormone for disease resistance, were down-regulated by high temperature during both the susceptible and resistant interactions, suggesting that enhanced Xa7-mediated resistance at high temperature is not dependent on salicylic acid signaling. A DNA sequence motif similar to known abscisic acid-responsive cis-regulatory elements was identified in the promoter region upstream of genes up-regulated in susceptible but down-regulated in resistant interactions. The results of our study suggest that the plant

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-15

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

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

    Science.gov (United States)

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

    2013-07-01

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

  11. Role of hydroperoxide lyase in white-backed planthopper (Sogatella furcifera Horváth)-induced resistance to bacterial blight in rice, Oryza sativa L.

    Science.gov (United States)

    Gomi, Kenji; Satoh, Masaru; Ozawa, Rika; Shinonaga, Yumi; Sanada, Sachiyo; Sasaki, Katsutomo; Matsumura, Masaya; Ohashi, Yuko; Kanno, Hiroo; Akimitsu, Kazuya; Takabayashi, Junji

    2010-01-01

    A pre-infestation of the white-backed planthopper (WBPH), Sogatella furcifera Horváth, conferred resistance to bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice (Oryza sativa L.) under both laboratory and field conditions. The infestation of another planthopper species, the brown planthopper (BPH) Nilaparvata lugens Stål, did not significantly reduce the incidence of bacterial blight symptoms. A large-scale screening using a rice DNA microarray and quantitative RT-PCR revealed that WBPH infestation caused the upregulation of more defence-related genes than did BPH infestation. Hydroperoxide lyase 2 (OsHPL2), an enzyme for producing C(6) volatiles, was upregulated by WBPH infestation, but not by BPH infestation. One C(6) volatile, (E)-2-hexenal, accumulated in rice after WBPH infestation, but not after BPH infestation. A direct application of (E)-2-hexenal to a liquid culture of Xoo inhibited the growth of the bacterium. Furthermore, a vapour treatment of rice plants with (E)-2-hexenal induced resistance to bacterial blight. OsHPL2-overexpressing transgenic rice plants exhibited increased resistance to bacterial blight. Based on these data, we conclude that OsHPL2 and its derived (E)-2-hexenal play some role in WBPH-induced resistance in rice.

  12. Mapping and marker-assisted selection of a brown planthopper resistance gene bph2 in rice (Oryza sativa L.).

    Science.gov (United States)

    Sun, Li-Hong; Wang, Chun-Ming; Su, Chang-Chao; Liu, Yu-Qiang; Zhai, Hu-Qu; Wan, Jian-Min

    2006-08-01

    Nilaparvata lugens Stål (brown planthopper, BPH), is one of the major insect pests of rice (Oryza sativa L.) in the temperate rice-growing region. In this study, ASD7 harboring a BPH resistance gene bph2 was crossed to a susceptible cultivar C418, a japonica restorer line. BPH resistance was evaluated using 134 F2:3 lines derived from the cross between "ASD7" and "C418". SSR assay and linkage analysis were carried out to detect bph2. As a result, the resistant gene bph2 in ASD7 was successfully mapped between RM7102 and RM463 on the long arm of chromosome 12, with distances of 7.6 cM and 7.2 cM, respectively. Meanwhile, both phenotypic selection and marker-assisted selection (MAS) were conducted in the BC1F1 and BC2F1 populations. Selection efficiencies of RM7102 and RM463 were determined to be 89.9% and 91.2%, respectively. It would be very beneficial for BPH resistance improvement by using MAS of this gene.

  13. High-resolution genetic mapping at the Bph15 locus for brown planthopper resistance in rice (Oryza sativa L.).

    Science.gov (United States)

    Yang, Haiyuan; You, Aiqing; Yang, Zhifan; Zhang, Futie; He, Ruifeng; Zhu, Lili; He, Guangcun

    2004-12-01

    Resistance to the brown planthopper (BPH), Nilaparvata lugens Stal, a devastating sucking insect pest of rice, is an important breeding objective in rice improvement programs. Bph15, one of the 17 major BPH resistance genes so far identified in both cultivated and wild rice, has been identified in an introgression line, B5, and mapped on chromosome 4 flanked by restriction fragment length polymorphism markers C820 and S11182. In order to pave the way for positional cloning of this gene, we have developed a high-resolution genetic map of Bph15 by positioning 21 DNA markers in the target chromosomal region. Mapping was based on a PCR-based screening of 9,472 F(2) individuals derived from a cross between RI93, a selected recombinant inbred line of B5 bearing the resistance gene Bph15, and a susceptible variety, Taichung Native 1, in order to identify recombinant plants within the Bph15 region. Recombinant F(2) individuals with the Bph15 genotype were determined by phenotype evaluation. Analysis of recombination events in the Bph15 region delimited the gene locus to an interval between markers RG1 and RG2 that co-segregated with the M1 marker. A genomic library of B5 was screened using these markers, and bacterial artificial chromosome clones spanning the Bph15 chromosome region were obtained. An assay of the recombinants using the sub-clones of these clones in combination with sequence analysis delimited the Bph15 gene to a genomic segment of approximately 47 kb. This result should serve as the basis for eventual isolation of the Bph15 resistance gene.

  14. The Novel Kasugamycin 2′-N-Acetyltransferase Gene aac(2′)-IIa, Carried by the IncP Island, Confers Kasugamycin Resistance to Rice-Pathogenic Bacteria

    OpenAIRE

    Yoshii, Atsushi; Moriyama, Hiromitsu; Fukuhara, Toshiyuki

    2012-01-01

    Kasugamycin (KSM), a unique aminoglycoside antibiotic, has been used in agriculture for many years to control not only rice blast caused by the fungus Magnaporthe grisea but also rice bacterial grain and seedling rot or rice bacterial brown stripe caused by Burkholderia glumae or Acidovorax avenae subsp. avenae, respectively. Since both bacterial pathogens are seed-borne and cause serious injury to rice seedlings, the emergence of KSM-resistant B. glumae and A. avenae isolates highlights the ...

  15. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho Outcrossing potential of glufosinate-resistant rice to red rice

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2002-08-01

    Full Text Available A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino e o arroz daninho como doador de pólen foi de 0,22 e 0,02%, respectivamente para os ecótipos de arroz daninho com glumas de cor palha e com glumas pretas. No caso inverso, quando o arroz daninho foi o receptor feminino e o arroz GM o doador de pólen, a taxa de cruzamento foi de 0,26 e 0,14%, para o arroz daninho com glumas palha e com glumas pretas, respectivamente. Os resultados deste estudo evidenciaram que ocorreu cruzamento natural entre o arroz GM e o arroz daninho em percentuais que variaram de 0,14 e 0,48%, respectivamente para o arroz preto e para o arroz vermelho. A fim de minimizar a possibilidade de hibridação, medidas de controle eficientes devem ser adotadas no sentido de prevenir a coincidência de floração das plantas de arroz daninho com a das plantas de arroz GM cultivado.The broad spectrum non-selective herbicide ammonium glufosinate, combined with genetically modified glufosinate-resistant rice cultivars (GM rice, may comprise a rice weed control system for red rice and other weeds that infest Brazilian rice fields. The objective of this study was to evaluate the potential for outcrossing and gene flow of GM rice to red rice. Natural outcrossing between adjacent field plots (1 m x 1 m was measured during the 1999/2000 production season in Brazil. The outcrossing rate of the GM rice as the female parent to red rice, as the pollen donor, was 0.22% for strawhull and 0.02% for the blackhull red rice, respectively. In the reciprocal

  16. Higher taxa as surrogates of species richness of spiders in insect-resistant transgenic rice

    Institute of Scientific and Technical Information of China (English)

    Sheng Lin; Min-Sheng You; Liette Vasseur; Guang Yang; Feng-Jing Liu; Feng Guo

    2012-01-01

    Biodiversity assessments can often be time- and resource-consuming.Several alternative approaches have been proposed to reduce sampling efforts,including indicator taxa and surrogates.In this study,we examine the reliability of higher taxon surrogates to predict species richness in two experimental rice fields of Fujian Province,southeastern China during 2005 and 2009.Spider samples in transgenic and nontransgenic plots were collected using a suction sampler.Both the genus and family surrogates had significant and positive linear relationships with species richness in the transgenic and nontransgenic rice fields.The rice varieties did not significantly influence the linear relationships.Our findings suggest that higher-taxon surrogacy could be a useful alternative to complete species inventory for risk assessments of transgenic rice.

  17. Mice fed a high-fat diet supplemented with resistant starch display marked shifts in the liver metabolome concurrent with altered gut bacteria

    Science.gov (United States)

    High-amylose maize resistant starch type 2 (HAMRS2) is a fermentable dietary fiber known to alter the gut milieu, including the gut microbiota, which may explain reported effects of resistant starch to ameliorate obesity-associated metabolic dysfunction. Our working hypothesis is that HAMRS2-induced...

  18. Utilization of rice husk ash to enhance radon resistant potential of concrete

    International Nuclear Information System (INIS)

    Jain, Ravinder; Kant, Krishan; Yadav, Mani Kant; Chauhan, R.P.

    2013-01-01

    The radiological and health implication posed by radon and their decay products are well known. The soil containing varying amount of radionuclides is the primary source of indoor radon. The indoor radon level depends upon its entrance through the pores of the ground and floor. Thus it is necessary to restrict the radon from soil to enter indoors by application of materials with low radon diffusion coefficient. The method used for radon shielding purpose in present study utilizes the rice husk ash for substitution with cement to achieve low diffusion coefficient. The study describes the method to optimize the condition of preparation of rice husk ash using X-ray diffraction and fluorescence spectroscopy techniques. The rice husk substitution with cement was optimized by compressive and porosity test of concrete cubes. The diffusion coefficient through concrete modified by rice husk ash was carried out by scintillation radon monitor and specially design radon diffusion chamber. The radon exhalation rates from concrete carried out using active technique decreasing radon emanation from concrete with increase of rice husk ash. The result of present study suggest substitution of 20-30% rice husk ash with cement to achieve lower radon diffusion and exhalation rates with higher compressive strength as compared to control concrete. (author)

  19. TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice.

    Science.gov (United States)

    Geng, Shuaifeng; Li, Aili; Tang, Lichuan; Yin, Lingjie; Wu, Liang; Lei, Cailin; Guo, Xiuping; Zhang, Xin; Jiang, Guanghuai; Zhai, Wenxue; Wei, Yuming; Zheng, Youliang; Lan, Xiujin; Mao, Long

    2013-08-01

    Calcium-dependent protein kinases (CPKs) are important Ca2+ signalling components involved in complex immune and stress signalling networks; but the knowledge of CPK gene functions in the hexaploid wheat is limited. Previously, TaCPK2 was shown to be inducible by powdery mildew (Blumeria graminis tritici, Bgt) infection in wheat. Here, its functions in disease resistance are characterized further. This study shows the presence of defence-response and cold-response cis-elements on the promoters of the A subgenome homoeologue (TaCPK2-A) and D subgenome homoeologue (TaCPK2-D), respectively. Their expression patterns were then confirmed by quantitative real-time PCR (qRT-PCR) using genome-specific primers, where TaCPK2-A was induced by Bgt treatment while TaCPK2-D mainly responded to cold treatment. Downregulation of TaCPK2-A by virus-induced gene silencing (VIGS) causes loss of resistance to Bgt in resistant wheat lines, indicating that TaCPK2-A is required for powdery mildew resistance. Furthermore, overexpression of TaCPK2-A in rice enhanced bacterial blight (Xanthomonas oryzae pv. oryzae, Xoo) resistance. qRT-PCR analysis showed that overexpression of TaCPK2-A in rice promoted the expression of OsWRKY45-1, a transcription factor involved in both fungal and bacterial resistance by regulating jasmonic acid and salicylic acid signalling genes. The opposite effect was found in wheat TaCPK2-A VIGS plants, where the homologue of OsWRKY45-1 was significantly repressed. These data suggest that modulation of WRKY45-1 and associated defence-response genes by CPK2 genes may be the common mechanism for multiple disease resistance in grass species, which may have undergone subfunctionalization in promoters before the formation of hexaploid wheat.

  20. High-resolution mapping of the brown planthopper resistance gene Bph6 in rice and characterizing its resistance in the 9311 and Nipponbare near isogenic backgrounds.

    Science.gov (United States)

    Qiu, Yongfu; Guo, Jianping; Jing, Shengli; Zhu, Lili; He, Guangcun

    2010-11-01

    Brown planthopper (Nilaparvata lugens Stål, BPH) is one of the most destructive insect pests of rice. Exploring resistance genes from diverse germplasms and incorporating them into cultivated varieties are critical for controlling this insect. The rice variety Swarnalata was reported to carry a resistance gene (designated Bph6), which has not yet been assigned to a chromosome location and the resistance mechanism is still unknown. In this study, we identified and mapped this gene using the F(2) and backcrossing populations and characterized its resistance in indica 9311 and japonica Nipponbare using near isogenic lines (NILs). In analysis of 9311/Swarnalata F(2) population, the Bph6 gene was located on the long arm of chromosome 4 between the SSR markers RM6997 and RM5742. The gene was further mapped precisely to a 25-kb region delimited between the STS markers Y19 and Y9; and the distance between these markers is 25-kb in Nipponbare genome. The Bph6 explained 77.5% of the phenotypic variance of BPH resistance in F(2) population and 84.9% in BC(2)F(2) population. Allele from Swarnalata significantly increased resistance to the BPH, resulted in a reduced damage score. In characterization of Bph6-mediated resistance, the BPH insects showed significant preference between NIL-9311 and 9311 in 3 h and between NIL-NIP and Nipponbare in 120 h after release. BPH growth and development were inhibited, and the insect's survival rates were lower on Bph6-NIL plants, compared with the parents 9311 and Nipponbare. The results indicate that the Bph6 exerted prolonged antixenotic and antibiotic effects in Bph6-NIL plants, and NIL-9311 plants showed a quicker and stronger effect toward BPH than NIL-NIP plants.

  1. Transgenerational variations in DNA methylation induced by drought stress in two rice varieties with distinguished difference to drought resistance.

    Directory of Open Access Journals (Sweden)

    Xiaoguo Zheng

    Full Text Available Adverse environmental conditions have large impacts on plant growth and crop production. One of the crucial mechanisms that plants use in variable and stressful natural environments is gene expression modulation through epigenetic modification. In this study, two rice varieties with different drought resistance levels were cultivated under drought stress from tilling stage to seed filling stage for six successive generations. The variations in DNA methylation of the original generation (G0 and the sixth generation (G6 of these two varieties in normal condition (CK and under drought stress (DT at seedling stage were assessed by using Methylation Sensitive Amplification Polymorphism (MSAP method. The results revealed that drought stress had a cumulative effect on the DNA methylation pattern of both varieties, but these two varieties had different responses to drought stress in DNA methylation. The DNA methylation levels of II-32B (sensitive and Huhan-3 (resistant were around 39% and 32%, respectively. Genome-wide DNA methylation variations among generations or treatments accounted for around 13.1% of total MSAP loci in II-32B, but was only approximately 1.3% in Huhan-3. In II-32B, 27.6% of total differentially methylated loci (DML were directly induced by drought stress and 3.2% of total DML stably transmitted their changed DNA methylation status to the next generation. In Huhan-3, the numbers were 48.8% and 29.8%, respectively. Therefore, entrainment had greater effect on Huhan-3 than on II-32B. Sequence analysis revealed that the DML were widely distributed on all 12 rice chromosomes and that it mainly occurred on the gene's promoter and exon region. Some genes with DML respond to environmental stresses. The inheritance of epigenetic variations induced by drought stress may provide a new way to develop drought resistant rice varieties.

  2. Gene manipulation for salt tolerance and blast resistance through in vitro techniques in rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Reddy, G.M.

    1990-01-01

    Full text: Rice calli generally lose regenerating ability in about 90 days. However, plant regeneration (60-70%) from 1500 day old embryo calli of 'Thellahamsa' cultivar has been established with 3% sorbitol/mannitol on LS media for efficient genetic manipulation at the cellular level. Matured embryo calli of four susceptible cultivars, 'Tellahamsa', 'Jaya', 'HR-2' and 'Zenith' were irradiated (0.1-0.5 kR) and challenged with Pyricularia oryzae spore suspensions (10 5 /ml) and with the major toxin d-picolinic acid (125-200 ppm). A total of 514 plants were regenerated from the resistant calli. The TC-2 plants exhibited varying degrees of resistance (66-78%). The genetic basis of resistance of regenerated plants and their progeny may help in understanding the mechanism. Rice embryo calli of nine scented and non-scented cultivars were challenged with NaCI (0.5-2%) and 25-50% sea water with or without proline. A total of 222 plants were regenerated. The progeny of TC-2 plants were evaluated with normal and saline soil (EC 13.5 ds/m) for yield parameters. These studies suggested that stable tolerant TC-2 plants under stress exhibited superior yield parameters and the salinity index ranged from 89.4-98.4. (author)

  3. Gene manipulation for salt tolerance and blast resistance through in vitro techniques in rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, G M [Department of Genetics, Osmania University, Hyderabad (India)

    1990-01-01

    Full text: Rice calli generally lose regenerating ability in about 90 days. However, plant regeneration (60-70%) from 1500 day old embryo calli of 'Thellahamsa' cultivar has been established with 3% sorbitol/mannitol on LS media for efficient genetic manipulation at the cellular level. Matured embryo calli of four susceptible cultivars, 'Tellahamsa', 'Jaya', 'HR-2' and 'Zenith' were irradiated (0.1-0.5 kR) and challenged with Pyricularia oryzae spore suspensions (10{sup 5}/ml) and with the major toxin d-picolinic acid (125-200 ppm). A total of 514 plants were regenerated from the resistant calli. The TC-2 plants exhibited varying degrees of resistance (66-78%). The genetic basis of resistance of regenerated plants and their progeny may help in understanding the mechanism. Rice embryo calli of nine scented and non-scented cultivars were challenged with NaCI (0.5-2%) and 25-50% sea water with or without proline. A total of 222 plants were regenerated. The progeny of TC-2 plants were evaluated with normal and saline soil (EC 13.5 ds/m) for yield parameters. These studies suggested that stable tolerant TC-2 plants under stress exhibited superior yield parameters and the salinity index ranged from 89.4-98.4. (author)

  4. Insect resistance to Nilaparvata lugens and Cnaphalocrocis medinalis in transgenic indica rice and the inheritance of gna+sbti transgenes.

    Science.gov (United States)

    Li, Guiying; Xu, Xinping; Xing, Hengtai; Zhu, Huachen; Fan, Qin

    2005-04-01

    Molecular genetic analysis and insect bioassay of transgenic indica rice 'Zhuxian B' plants carrying snowdrop lectin gene (gna) and soybean trypsin inhibitor gene (sbti) were investigated in detail. PCR, 'dot' blot and PCR-Southern blot analysis showed that both transgenes had been incorporated into the rice genome and transmitted up to R3 progeny in most lines tested. Some transgenic lines exhibited Mendelian segregation, but the other showed either 1:1 (positive: negative for the transgenes) or other aberrant segregation patterns. The segregation patterns of gna gene crossed between R2 and R3 progeny. In half of transgenic R3 lines, gna and sbti transgenes co-segregated. Two independent homozygous lines expressing double transgenes were identified in R3 progeny. Southern blot analysis demonstrated that the copy numbers of integrated gna and sbti transgenes varied from one to ten in different lines. Insect bioassay data showed that most transgenic plants had better resistance to both Nilaparvata lugens (Stahl) and Cnaphalocrocis medinalis (Guenee) than wild-type plants. The insect resistance of transgenic lines increased with the increase in transgene positive ratio in most of the transgenic lines. In all, we obtained nine lines of R3 transgenic plants, including one pure line, which had better resistance to both N lugens and C medinalis than wild-type plants. Copyright 2005 Society of Chemical Industry.

  5. Co-evolutionary interactions between host resistance and pathogen avirulence genes in rice-Magnaporthe oryzae pathosystem.

    Science.gov (United States)

    Singh, Pankaj Kumar; Ray, Soham; Thakur, Shallu; Rathour, Rajeev; Sharma, Vinay; Sharma, Tilak Raj

    2018-06-01

    Rice and Magnaporthe oryzae constitutes an ideal pathosystem for studying host-pathogen interaction in cereals crops. There are two alternative hypotheses, viz. Arms race and Trench warfare, which explain the co-evolutionary dynamics of hosts and pathogens which are under continuous confrontation. Arms race proposes that both R- and Avr- genes of host and pathogen, respectively, undergo positive selection. Alternatively, trench warfare suggests that either R- or Avr- gene in the pathosystem is under balanced selection intending to stabilize the genetic advantage gained over the opposition. Here, we made an attempt to test the above-stated hypotheses in rice-M. oryzae pathosystem at loci of three R-Avr gene pairs, Piz-t-AvrPiz-t, Pi54-AvrPi54 and Pita-AvrPita using allele mining approach. Allele mining is an efficient way to capture allelic variants existing in the population and to study the selective forces imposed on the variants during evolution. Results of nucleotide diversity, neutrality statistics and phylogenetic analyses reveal that Piz-t, Pi54 and AvrPita are diversified and under positive selection at their corresponding loci, while their counterparts, AvrPiz-t, AvrPi54 and Pita are conserved and under balancing selection, in nature. These results imply that rice-M. oryzae populations are engaged in a trench warfare at least at the three R/Avr loci studied. It is a maiden attempt to study the co-evolution of three R-Avr gene pairs in this pathosystem. Knowledge gained from this study will help in understanding the evolutionary dynamics of host-pathogen interaction in a better way and will also aid in developing new durable blast resistant rice varieties in future. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Three-generation reproduction toxicity study of genetically modified rice with insect resistant genes.

    Science.gov (United States)

    Hu, Yichun; Zhuo, Qin; Gong, Zhaolong; Piao, Jianhua; Yang, Xiaoguang

    2017-01-01

    In the present work, we evaluated the three generation reproductive toxicity of the genetically modified rice with insectresistant cry1Ac and sck genes. 120 Sprague-Dawley (SD) rats were divided into three groups which were fed with genetically modified rice diet (GM group), parental control rice diet (PR group) and AIN-93 control diet (both used as negative control) respectively. Bodyweight, food consumption, reproductive data, hematological parameters, serum chemistry, relative organ weights and histopathology for each generation were examined respectively. All the hematology and serum chemistry parameters, organ/body weight indicators were within the normal range or no change to the adverse direction was observed, although several differences in hematology and serum chemistry parameters (WBC, BUN, LDH of male rat, PLT, PCT, MPV of female rats), reproductive data (rate of morphologically abnormal sperm) were observed between GM rice group and two control groups. No macroscopic or histological adverse effects were found or considered as treatment-related, either. Overall, the three generation study of genetically modified rice with cry1Ac and sck genes at a high level showed no unintended adverse effects on rats's reproductive system. Copyright © 2016. Published by Elsevier Ltd.

  7. Ortholog Alleles at Xa3/Xa26 Locus Confer Conserved Race-Specific Resistance against Xanthomonas oryzae in Rice

    Institute of Scientific and Technical Information of China (English)

    Hong-Jing Li; Xiang-Hua Li; Jing-Hua Xiao; Rod A. Wing; Shi-Ping Wang

    2012-01-01

    The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv.oryzae (Xoo),which causes bacterial blight disease,belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.).This family encodes leucine-rich repeat (LRR) receptor kinasetype proteins.Here,we show that the orthologs (alleles) of Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3,from wild Oryza species O.officinalis (CC genome) and O.minuta (BBCC genome),respectively,were also R genes against Xoo.Xa3/Xa26-2 and Xa3/Xa26-3 conferred resistance to 16 of the 18 Xoo strains examined.Comparative sequence analysis of the Xa3/Xa26 families in the two wild Oryza species showed that Xa3/Xa26-3 appeared to have originated from the CC genome of O.minuta.The predicted proteins encoded by Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3 share 91-99% sequence identity and 94-99% sequence similarity.Transgenic plants carrying a single copy of Xa3/Xa26,Xa3/Xa26-2,or Xa3/Xa26-3,in the same genetic background,showed a similar resistance spectrum to a set of Xoo strains,although plants carrying Xa3/Xa26-2 or Xa3/Xa26-3 showed lower resistance levels than the plants carrying Xa3/Xa26.These results suggest that the Xa3/Xa26 locus predates the speciation of A and C genome,which is approximately 7.5 million years ago.Thus,the resistance specificity of this locus has been conserved for a long time.

  8. Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat.

    Science.gov (United States)

    Mao, Donghai; Yu, Li; Chen, Dazhou; Li, Lanying; Zhu, Yuxing; Xiao, Yeqing; Zhang, Dechun; Chen, Caiyan

    2015-07-01

    Dongxiang wild rice is phylogenetically close to temperate japonica and contains multiple cold resistance loci conferring its adaptation to high-latitude habitat. Understanding the nature of adaptation in wild populations will benefit crop breeding in the development of climate-resilient crop varieties. Dongxiang wild rice (DXWR), the northernmost common wild rice known, possesses a high degree of cold tolerance and can survive overwintering in its native habitat. However, to date, it is still unclear how DXWR evolved to cope with low-temperature environment, resulting in limited application of DXWR in rice breeding programs. In this study, we carried out both QTL mapping and phylogenetic analysis to discern the genetic mechanism underlying the strong cold resistance. Through a combination of interval mapping and single locus analysis in two genetic populations, at least 13 QTLs for seedling cold tolerance were identified in DXWR. A phylogenetic study using both genome-wide InDel markers and markers associated with cold tolerance loci reveals that DXWR belongs to the Or-III group, which is most closely related to cold-tolerant Japonica rice rather than to the Indica cultivars that are predominant in the habitat where DXWR grows. Our study paves the way toward an understanding of the nature of adaptation to a northern habitat in O. rufipogon. The QTLs identified in DXWR in this study will be useful for molecular breeding of cold-tolerant rice.

  9. The Caryopsis of Red-Grained Rice Has Enhanced Resistance to Fungal Attack

    Directory of Open Access Journals (Sweden)

    Alberto Gianinetti

    2018-06-01

    Full Text Available Seed persistence in the soil is threatened by microorganisms, but the seed coat helps protect the seed from them. Although modern rice (Oryza sativa L. cultivars have a whitish caryopsis, some varieties have a red caryopsis coat, a trait typical of wild Oryza species. The red colour is due to the oxidation of proanthocyanidins, a class of flavonoids that is found in the outer layers of the seed in many species. We aimed to assess whether these natural compounds (proanthocyanidins and proanthocyanidin-derived pigment have some protective effect against microbial attacks. Dehulled caryopses of white-grained and red-grained rice genotypes were employed to assay fungal infection. Specifically, three white-grained rice cultivars (Perla, Augusto, and Koral and three red-grained rice varieties (Perla Rosso, Augusto Rosso, and Koral Rosso were used. In a first test, the caryopses were infected with Epicoccum nigrum at 10 °C, and seedling growth was then assessed at 30 °C. In a second test, the degree of infection by the mycotoxigenic fungus Fusarium sporotrichioides was assayed by measuring the accumulation of T-2/HT-2 toxins in the caryopses. Infection was performed at 10 °C to prevent rice germination while allowing fungal growth. In both the tests, red caryopses showed reduced, or delayed, infection with respect to white ones. One black-grained cultivar (Venere was assayed for the accumulation of T-2/HT-2 toxins as well, with results corresponding to those of the red-grained rice varieties. We argue that the red pigment accumulating in the caryopsis coat, and/or the proanthocyanidins associated with it, provides a protective barrier against challenging microorganisms.

  10. Overexpression of miR529a confers enhanced resistance to oxidative stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Yue, Erkui; Liu, Zhen; Li, Chao; Li, Yu; Liu, Qiuxiang; Xu, Jian-Hong

    2017-07-01

    Overexpressing miR529a can enhance oxidative stress resistance by targeting OsSPL2 and OsSPL14 genes that can regulate the expression of their downstream SOD and POD related genes. MicroRNAs are involved in the regulation of plant developmental and physiological processes, and their expression can be altered when plants suffered environment stresses, including salt, oxidative, drought and Cadmium. The expression of microRNA529 (miR529) can be induced under oxidative stress. However, its biological function under abiotic stress responses is still unclear. In this study, miR529a was overexpressed to investigate the function of miR529a under oxidative stress in rice. Our results demonstrated that the expression of miR529a can be induced by exogenous H 2 O 2 , and overexpressing miR529a can increase plant tolerance to high level of H 2 O 2 , resulting in increased seed germination rate, root tip cell viability, reduced leaf rolling rate and chlorophyll retention. The expression of oxidative stress responsive genes and the activities of superoxide dismutase (SOD) and peroxidase (POD) were increased in miR529a overexpression plant, which could help to reduce redundant reactive oxygen species (ROS). Furthermore, only OsSPL2 and OsSPL14 were targeted by miR529a in rice seedlings, repressing their expression in miR529aOE plants could lead to strengthen plant tolerance to oxidation stress. Our study provided the evidence that overexpression of miR529a could strengthen oxidation resistance, and its target genes OsSPL2 and OsSPL14 were responsible for oxidative tolerance, implied the manipulation of miR529a and its target genes regulation on H 2 O 2 related response genes could improve oxidative stress tolerance in rice.

  11. Fine mapping of the rice bacterial blight resistance gene Xa-4 and its co-segregation marker

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An F2 population developed from the Xa-4 near isogenic lines,IR24 and IRBB4,was used for fine mapping of the rice bacterial blight resistance gene,Xa-4.Some restriction fragment length polymorphism (RFLP) markers on the high-density map constructed by Harushima et al.and the amplified DNA fragments homologous to the conserved domains of plant disease resistance (R) genes were used to construct the genetic linkage map around the gene Xa-4 by scoring susceptible individuals in the population.Xa-4 was mapped between the RFLP marker G181 and the polymerase chain reaction (PCR) marker M55.The R gene homologous fragment marker RS13 was found co-segregating with Xa-4 by analyzing all the plants in the population.This result opened an approach to map-based cloning of this gene,and marker RS13 can be applied to molecular marker-assisted selection of Xa-4 in rice breeding programs.

  12. Release of a new lodging-resistant mutant cultivar produced by gamma-rays in glutinous rice

    International Nuclear Information System (INIS)

    Yamaguchi, Hikoyuki; Igarashi, Isao; Sato, Takeshi

    2001-01-01

    To obtain short culm mutants with lodging resistance, while retaining the other desirable traits, such as an excellent quality of the original variety, dry seeds of a glutinous rice cultivar Mezuru were exposed to gamma-rays. In M3, thirty plants were selected from 4020 plants, based on the short culm length. From the results of the subsequent yield and adaptability tests, a promising mutant line was called by the name of Sakata-Mezuru as a new cultivar in 1996. This mutant variety was mainly characterized by shortening of each internode, especially the lowest internode, and at harvest it was more adaptable to mechanical work due to the lodging resistance than its parent. It was demonstrated that the grain quality of the mutant equals to or slightly surpasses that of the parent. Sakata-Mezuru has been registered in February of 2001 and officially released. (author)

  13. Rice Gene Network Inferred from Expression Profiling of Plants Overexpressing OsWRKY13,a Positive Regulator of Disease Resistance

    Institute of Scientific and Technical Information of China (English)

    Deyun Qiu; Jun Xiao; Weibo Xie; Hongbo Liu; Xianghua Li; Lizhong Xiong; Shiping Wang

    2008-01-01

    Accumulating information indicates that plant disease resistance signaling pathways frequently interact with other pathways regulating developmental processes or abiotic stress responses. However, the molecular mechanisms of these types of crosstalk remain poorly understood in most cases. Here we report that OsWRKY13, an activator of rice resistance to both bacterial and fungal pathogens, appears to function as a convergent point for crosstalk among the pathogen-induced salicylate-dependent defense pathway and five other physiologic pathways. Genome-wide analysis of the expression profiles of OsWRKY13-overexpressing lines suggests that OsWRKY13 directly or indirectly regulates the expression of more than 500 genes that are potentially involved in different physiologic processes according to the classification of the Gene Ontology database. By comparing the expression patterns of genes functioning in known pathways or cellular processes of pathogen infection and the phenotypes between OsWRKY13-overexpressing and wildtype plants, our data suggest that OsWRKY13 is also a regulator of other physiologic processes during pathogen infection. The OsWRKY13-associated disease resistance pathway synergistically interacts via OsWRKY13 with the glutathione/glutaredoxin system and flavonoid biosynthesis pathway to monitor redox homeostasis and to putatively enhance the biosynthesis of antimicrobial flavonoid phytoalexins, respectively, in OsWRKY13-overexpressing lines. Meanwhile, the OsWRKY13-associated disease resistance pathway appears to interact antagonistically with the SNAC1-mediated abiotic stress defense pathway, jasmonic acid signaling pathway, and terpenoid metabolism pathway via OsWRKY13 to suppress salt and cold defense responses as well as to putatively retard rice growth and development.

  14. Evaluation of RNA extraction methods in rice and their application in expression analysis of resistance genes against Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Parisa Azizi

    2017-01-01

    Full Text Available Extraction of RNA of high quality and integrity is essential for gene expression studies and all downstream RNA-based techniques. The leaves of 16 merit Malaysian rice varieties were used to isolate total RNA using five different methods. The quantity, quality and integrity of extracted RNA were confirmed using three different means. The ratios of A260/280 ranged from 2.12 to 2.20. Electrophoresis (1.5% agarose gel was performed, illustrating intact and sharp bands representing the 28S, 18S, 5.8S and 5S ribosomal subunits of RNA, presenting intact RNA. RNA quality was verified using semi-quantitative polymerase chain reaction (sqPCR. The objective of this study was to identify different genes involved in the resistance of rice plants using high-quality RNA extracted 31 h after inoculation of Magnaporthe oryzae pathotype P7.2. The expression levels of eight blast resistance genes, Pikh, Pib, Pita, Pi21, Pi9, Os11gRGA8, OsWRKY22 and OsWRKY45, were evaluated by real-time PCR (RT-PCR. Real-time PCR was performed to identify candidate genes using RNA extracted by the TRIzol method, which showed the highest score compared with other methods in terms of RNA quantity, purity and integrity. In addition, the results of real-time PCR confirmed that the up-regulation of seven blast resistance genes may confer stronger resistance for the MR 276 variety against M. oryzae pathotype P7.2.

  15. Selectable antibiotic resistance marker gene-free transgenic rice harbouring the garlic leaf lectin gene exhibits resistance to sap-sucking planthoppers.

    Science.gov (United States)

    Sengupta, Subhadipa; Chakraborti, Dipankar; Mondal, Hossain A; Das, Sampa

    2010-03-01

    Rice, the major food crop of world is severely affected by homopteran sucking pests. We introduced coding sequence of Allium sativum leaf agglutinin, ASAL, in rice cultivar IR64 to develop sustainable resistance against sap-sucking planthoppers as well as eliminated the selectable antibiotic-resistant marker gene hygromycin phosphotransferase (hpt) exploiting cre/lox site-specific recombination system. An expression vector was constructed containing the coding sequence of ASAL, a potent controlling agent against green leafhoppers (GLH, Nephotettix virescens) and brown planthopper (BPH, Nilaparvata lugens). The selectable marker (hpt) gene cassette was cloned within two lox sites of the same vector. Alongside, another vector was developed with chimeric cre recombinase gene cassette. Reciprocal crosses were performed between three single-copy T(0) plants with ASAL- lox-hpt-lox T-DNA and three single-copy T(0) plants with cre-bar T-DNA. Marker gene excisions were detected in T(1) hybrids through hygromycin sensitivity assay. Molecular analysis of T(1) plants exhibited 27.4% recombination efficiency. T(2) progenies of L03C04(1) hybrid parent showed 25% cre negative ASAL-expressing plants. Northern blot, western blot and ELISA showed significant level of ASAL expression in five marker-free T(2) progeny plants. In planta bioassay of GLH and BPH performed on these T(2) progenies exhibited radical reduction in survivability and fecundity compared with the untransformed control plants.

  16. Bph32, a novel gene encoding an unknown SCR domain-containing protein, confers resistance against the brown planthopper in rice

    Science.gov (United States)

    Ren, Juansheng; Gao, Fangyuan; Wu, Xianting; Lu, Xianjun; Zeng, Lihua; Lv, Jianqun; Su, Xiangwen; Luo, Hong; Ren, Guangjun

    2016-01-01

    An urgent need exists to identify more brown planthopper (Nilaparvata lugens Stål, BPH) resistance genes, which will allow the development of rice varieties with resistance to BPH to counteract the increased incidence of this pest species. Here, using bioinformatics and DNA sequencing approaches, we identified a novel BPH resistance gene, LOC_Os06g03240 (MSU LOCUS ID), from the rice variety Ptb33 in the interval between the markers RM19291 and RM8072 on the short arm of chromosome 6, where a gene for resistance to BPH was mapped by Jirapong Jairin et al. and renamed as “Bph32”. This gene encodes a unique short consensus repeat (SCR) domain protein. Sequence comparison revealed that the Bph32 gene shares 100% sequence identity with its allele in Oryza latifolia. The transgenic introgression of Bph32 into a susceptible rice variety significantly improved resistance to BPH. Expression analysis revealed that Bph32 was highly expressed in the leaf sheaths, where BPH primarily settles and feeds, at 2 and 24 h after BPH infestation, suggesting that Bph32 may inhibit feeding in BPH. Western blotting revealed the presence of Pph (Ptb33) and Tph (TN1) proteins using a Penta-His antibody, and both proteins were insoluble. This study provides information regarding a valuable gene for rice defence against insect pests. PMID:27876888

  17. Bph32, a novel gene encoding an unknown SCR domain-containing protein, confers resistance against the brown planthopper in rice.

    Science.gov (United States)

    Ren, Juansheng; Gao, Fangyuan; Wu, Xianting; Lu, Xianjun; Zeng, Lihua; Lv, Jianqun; Su, Xiangwen; Luo, Hong; Ren, Guangjun

    2016-11-23

    An urgent need exists to identify more brown planthopper (Nilaparvata lugens Stål, BPH) resistance genes, which will allow the development of rice varieties with resistance to BPH to counteract the increased incidence of this pest species. Here, using bioinformatics and DNA sequencing approaches, we identified a novel BPH resistance gene, LOC_Os06g03240 (MSU LOCUS ID), from the rice variety Ptb33 in the interval between the markers RM19291 and RM8072 on the short arm of chromosome 6, where a gene for resistance to BPH was mapped by Jirapong Jairin et al. and renamed as "Bph32". This gene encodes a unique short consensus repeat (SCR) domain protein. Sequence comparison revealed that the Bph32 gene shares 100% sequence identity with its allele in Oryza latifolia. The transgenic introgression of Bph32 into a susceptible rice variety significantly improved resistance to BPH. Expression analysis revealed that Bph32 was highly expressed in the leaf sheaths, where BPH primarily settles and feeds, at 2 and 24 h after BPH infestation, suggesting that Bph32 may inhibit feeding in BPH. Western blotting revealed the presence of Pph (Ptb33) and Tph (TN1) proteins using a Penta-His antibody, and both proteins were insoluble. This study provides information regarding a valuable gene for rice defence against insect pests.

  18. Nitrogen fertilizer application affects lodging resistance by altering secondary cell wall synthesis in japonica rice (Oryza sativa).

    Science.gov (United States)

    Zhang, Wujun; Wu, Longmei; Ding, Yanfeng; Yao, Xiong; Wu, Xiaoran; Weng, Fei; Li, Ganghua; Liu, Zhenghui; Tang, She; Ding, Chengqiang; Wang, Shaohua

    2017-09-01

    Stem mechanical strength is an important agricultural quantitative trait that is closely related to lodging resistance in rice, which is known to be reduced by fertilizer with higher levels of nitrogen. To understand the mechanism that regulates stem mechanical strength in response to nitrogen, we analysed stem morphology, anatomy, mechanical properties, cell wall components, and expression of cell wall-related genes, in two varieties of japonica rice, namely, Wuyunjing23 (lodging-resistant variety) and W3668 (lodging-susceptible variety). The results showed that higher nitrogen fertilizer increased the lodging index in both varieties due to a reduction in breaking strength and bending stress, and these changes were larger in W3668. Cellulose content decreased slightly under higher nitrogen fertilizer, whereas lignin content reduced remarkably. Histochemical staining revealed that high nitrogen application decreased lignin deposition in the secondary cell wall of the sclerenchyma cells and vascular bundle cells compared with the low nitrogen treatments, while it did not alter the pattern of cellulose deposition in these cells in both Wuyunjing23 and W3668. In addition, the expression of the genes involved in lignin biosynthesis, OsPAL, OsCoMT, Os4CL3, OsCCR, OsCAD2, OsCAD7, OsCesA4, and OsCesA7, were also down-regulated under higher nitrogen conditions at the early stage of culm growth. These results suggest that the genes involved in lignin biosynthesis are down-regulated by higher nitrogen fertilizer, which causes lignin deficiency in the secondary cell walls and the weakening of mechanical tissue structure. Subsequently, this results in these internodes with reduced mechanical strength and poor lodging resistance.

  19. CRISPR/Cas9-Mediated Gene Editing in Rice (Oryza sativa L. japonica cv. Katy) for Stable Resistance against Blast Fungus (Magnaporthe oryzae)

    Science.gov (United States)

    Rice blast is a recurring and devastating disease in the USA and worldwide. In the USA, the blast-resistance (R) genes found in a tropical japonica cultivar, Katy, reduce blast damages from 1990 to present. The cultivar is still used as a principal donor of blast R genes in developing numerous elit...

  20. A genome-wide association study of a global rice panel reveals resistance in Oryza sativa to root-knot nematodes.

    Science.gov (United States)

    Dimkpa, Stanley O N; Lahari, Zobaida; Shrestha, Roshi; Douglas, Alex; Gheysen, Godelieve; Price, Adam H

    2016-02-01

    The root-knot nematode Meloidogyne graminicola is one of the most serious nematode pests worldwide and represents a major constraint on rice production. While variation in the susceptibility of Asian rice (Oryza sativa) exists, so far no strong and reliable resistance has been reported. Quantitative trait loci for partial resistance have been reported but no underlying genes have been tagged or cloned. Here, 332 accessions of the Rice Diversity Panel 1 were assessed for gall formation, revealing large variation across all subpopulations of rice and higher susceptibility in temperate japonica accessions. Accessions Khao Pahk Maw and LD 24 appeared to be resistant, which was confirmed in large pot experiments where no galls were observed. Detailed observations on these two accessions revealed no nematodes inside the roots 2 days after inoculation and very few females after 17 days (5 in Khao Pahk Maw and 100 in the susceptible controls). These two cultivars appear ideal donors for breeding root-knot nematode resistance. A genome-wide association study revealed 11 quantitative trait loci, two of which are close to epistatic loci detected in the Bala x Azucena population. The discussion highlights a small number of candidate genes worth exploring further, in particular many genes with lectin domains and genes on chromosome 11 with homology to the Hordeum Mla locus. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  1. The novel kasugamycin 2'-N-acetyltransferase gene aac(2')-IIa, carried by the IncP island, confers kasugamycin resistance to rice-pathogenic bacteria.

    Science.gov (United States)

    Yoshii, Atsushi; Moriyama, Hiromitsu; Fukuhara, Toshiyuki

    2012-08-01

    Kasugamycin (KSM), a unique aminoglycoside antibiotic, has been used in agriculture for many years to control not only rice blast caused by the fungus Magnaporthe grisea but also rice bacterial grain and seedling rot or rice bacterial brown stripe caused by Burkholderia glumae or Acidovorax avenae subsp. avenae, respectively. Since both bacterial pathogens are seed-borne and cause serious injury to rice seedlings, the emergence of KSM-resistant B. glumae and A. avenae isolates highlights the urgent need to understand the mechanism of resistance to KSM. Here, we identified a novel gene, aac(2')-IIa, encoding a KSM 2'-N-acetyltransferase from both KSM-resistant pathogens but not from KSM-sensitive bacteria. AAC(2')-IIa inactivates KSM, although it reveals no cross-resistance to other aminoglycosides. The aac(2')-IIa gene from B. glumae strain 5091 was identified within the IncP genomic island inserted into the bacterial chromosome, indicating the acquisition of this gene by horizontal gene transfer. Although excision activity of the IncP island and conjugational gene transfer was not detected under the conditions tested, circular intermediates containing the aac(2')-IIa gene were detected. These results indicate that the aac(2')-IIa gene had been integrated into the IncP island of a donor bacterial species. Molecular detection of the aac(2')-IIa gene could distinguish whether isolates are resistant or susceptible to KSM. This may contribute to the production of uninfected rice seeds and lead to the effective control of these pathogens by KSM.

  2. Green tissue-specific co-expression of chitinase and oxalate oxidase 4 genes in rice for enhanced resistance against sheath blight.

    Science.gov (United States)

    Karmakar, Subhasis; Molla, Kutubuddin Ali; Chanda, Palas K; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2016-01-01

    Green tissue-specific simultaneous overexpression of two defense-related genes ( OsCHI11 & OsOXO4 ) in rice leads to significant resistance against sheath blight pathogen ( R. solani ) without distressing any agronomically important traits. Overexpressing two defense-related genes (OsOXO4 and OsCHI11) cloned from rice is effective at enhancing resistance against sheath blight caused by Rhizoctonia solani. These genes were expressed under the control of two different green tissue-specific promoters, viz. maize phosphoenolpyruvate carboxylase gene promoter, PEPC, and rice cis-acting 544-bp DNA element, immediately upstream of the D54O translational start site, P D54O-544 . Putative T0 transgenic rice plants were screened by PCR and integration of genes was confirmed by Southern hybridization of progeny (T1) rice plants. Successful expression of OsOXO4 and OsCHI11 in all tested plants was confirmed. Expression of PR genes increased significantly following pathogen infection in overexpressing transgenic plants. Following infection, transgenic plants exhibited elevated hydrogen peroxide levels, significant changes in activity of ROS scavenging enzymes and reduced membrane damage when compared to their wild-type counterpart. In a Rhizoctonia solani toxin assay, a detached leaf inoculation test and an in vivo plant bioassay, transgenic plants showed a significant reduction in disease symptoms in comparison to non-transgenic control plants. This is the first report of overexpression of two different PR genes driven by two green tissue-specific promoters providing enhanced sheath blight resistance in transgenic rice.

  3. Induction of resistance to blast disease in an elite rice cultivar 'IR 50'

    International Nuclear Information System (INIS)

    Sarma, N.P.; Rao, G.J.N.; Row, K.V.S.R.K.

    2001-01-01

    Full text: One of the most promising techniques for producing disease resistant forms of plants is the use of mutagenic agents. It has been demonstrated by several workers that genetic variability for several desired characters can be induced successfully through mutations and its practical value in plant improvement programmes has been well established. The main advantage of mutation breeding is the possibility of improving one or two characters without changing the rest of the genotype. The elite cultivar, 'IR 50' (IR 2153-14-1-6-2/IR 28//IR 36) was developed at IRRI, Los Banos, The Philippines and was released in India for the State of Tamil Nadu in 1982. It is highly responsive to fertilizer, records high yields and possesses good grain characters. It matured in just more than 100 days and was ideal for both samba and navarai seasons in Tamil Nadu. But, the cultivar was shown to be highly susceptible to blast (causative organism Magnaportha grisea) causing extensive losses year after year. With the objective of developing high yielding, blast tolerant mutant lines from IR 50, the mutation approach was adopted and both physical (gamma-rays from 60 Co) and chemical mutagens (EMS - ethyl methanesulphonate and sodium azide) were employed on dry seeds. The M1 generation was grown in closely spaced plants. One hundred and sixty-eight derived families were grown in M 2 . In M 3 generation, 128 M 3 families were further selected for evaluation in M4 and M5. Based on evaluation of yield and other attributes, a total of 85 mutants were finally selected and evaluated for their stability. In selection of the mutants, it was ensured that all the selected mutants resemble the parent for both agronomic and quality characteristics. The evaluation of these mutant lines for the level of tolerance to blast disease was conducted at CRRI over a number of years under both artificial and natural conditions. These mutant lines showed varied levels of tolerance to blast in comparison

  4. In vitro Starch Hydrolysis Rate, Physico-chemical Properties and Sensory Evaluation of Butter Cake Prepared Using Resistant Starch Type III Substituted for Wheat Flour.

    Science.gov (United States)

    Pongjanta, J; Utaipattanaceep, A; Naivikul, O; Piyachomkwan, K

    2008-09-01

    Resistant starch type III (RS III) derived from enzymatically debranched high amylose rice starch was prepared and used to make butter cake at different levels (0, 5, 10, 15 and 20%) in place of wheat flour. Physico-chemical properties, sensory evaluation, and in vitro starch hydrolysis rate of the developed butter cake were investigated. This study showed that the content of resistant starch in butter cake increased significantly (Pcake with RS III replacement had a significantly lower in vitro starch hydrolysis rate compared to the control cake (0% RS III). The rates of starch hydrolysis from 0 to 180 min digestion time for 0, 5, 10 15, and 20% RS III in place of wheat flour in butter cakes were 3.70 to 67.65%, 2.97 to 64.86%, 2.86 to 59.99%, 2.79 to 55.96 and 2.78 to 53.04% respectively. The physico-chemical properties of 5 to 10% RS III substituted with wheat flour in the butter cake were not significantly different from the control cake and were moderately accepted by panellists in the sensory evaluation test.

  5. Effects of seed mixture sowing with resistant and susceptible rice on population dynamics of target planthoppers and non-target stemborers and leaffolders.

    Science.gov (United States)

    Li, Zhuo; Wan, Guijun; Wang, Long; Parajulee, Megha N; Zhao, Zihua; Chen, Fajun

    2018-07-01

    The widespread planting of insect-resistant crops has caused a dramatic shift in agricultural landscapes, thus raising concerns about the potential impact on both target and non-target pests worldwide. In this study, we examined the potential effects of six seed mixture ratios of insect-resistance dominance [100% (R100), 95% (S05R95), 90% (S10R90), 80% (S20R80), 60% (S40R60), and 0% (S100)] on target and non-target pests in a 2-year field trial in southern China. The occurrence of the target pests Nilaparvata lugens and Sogatella furcifera decreased with an increase in the ratio of resistant rice, and mixture ratios with ≥90% resistant rice significantly increased the pest suppression efficiency, with the lowest occurrences of the non-target pests Sesamia inferens, Chilo suppressalis and Cnaphalocrocis medinalis for S100 and S10R90 seed mixture ratios. Furthermore, there were no significant differences in the 1000-grain dry weight and grain yield between R100 and other treatments with ≥80% resistant seeds in the mixture (S20R80, S10R90 and S05R95). S10R90 produced a good yield and provided the most effective control of both target and non-target pests, with the potential to significantly reduce the application of chemical pesticides for integrated pest management in paddy fields. It is further presumed that the strategy of seed mixture with resistant and susceptible rice would be advantageous for rice yield stability. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  6. Rice mutation breeding for resistance against leaf blight disease and brown planthopper

    International Nuclear Information System (INIS)

    Mugiono; Ismachin, M

    1981-01-01

    Seeds of Pelita 1/1 were treated variously with EMS 1%, 20, 30, 35, 40 and 50 krad doses gamma rays from a Co 60 source. The 1% EMS treatment, of presoaking for 36 hours in distilled water and stored for one week before sowing, yielded more mutants resistant against bacterial leaf blight compared to other treatments with EMS. Treatment with 20 krad of gamma rays gave an indication of a good probability for improving resistance. Screening for brown planthopper resistance among 350 M 4 lines yielded 4 moderate resistant (MR) lines. However, no resistant line was found. From 36 crosses between the mutants and IR-26 or mutants with Mudgo 86 promising lines were found. The promising lines, beside resistant against brown planthopper, were selected based on early maturity and short stem. (author)

  7. Effects of a treatment with Se-rich rice flour high in resistant starch on enteric dysbiosis and chronic inflammation in diabetic ICR mice.

    Science.gov (United States)

    Yuan, Huaibo; Wang, Wenjuan; Chen, Deyi; Zhu, Xiping; Meng, Lina

    2017-05-01

    Enteric dysbiosis is associated with chronic inflammation and interacts with obesity and insulin resistance. Obesity and diabetes are induced in ICR (Institute of Cancer Research) mice fed a high-fat diet and administered a streptozocin injection. These mice were treated with normal rice (NR), normal rice with a high resistant starch content (NRRS) or Se-rich rice (selenium-enriched rice) with a high resistant starch content (SRRS). Faecal cell counts of Bifidobacterium, Lactobacillus and Enterococcus were significantly higher in SRRS-treated mice than in diabetic controls, while Enterobacter cloacae were lower. Similar results were also found in NRRS-treated mice. In contrast, no significant difference was found between NR-treated and diabetic control groups. The treatments with SRRS and NRRS reduced the faecal pH values of the diabetic mice. Regarding the inflammatory factor levels, lower levels of serum C-reactive protein (CRP), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), nuclear factor-k-gene binding (NF-κB) and leptin (LEP) and higher adiponutrin (ADPN) levels were found in the SRRS and NRRS-treated mice compared with the diabetic and NR-treated mice. In addition, the CRP, IL-6 and NF-κB levels in the SRRS-treated mice were significantly reduced compared with those observed in the NRRS-treated mice. The reverse transcription-PCR (RT-PCR) results showed that the SRRS and NRRS-treated mice presented higher expression levels of orphan G protein-coupled receptor 41 (GPR41) and orphan G protein-coupled receptor 43 (GPR43) proteins compared with diabetic mice and NR-treated mice. These results indicate that treatments with rice high in RS exert beneficial effects by improving enteric dysbiosis and chronic inflammation. In addition, selenium and RS may exert synergistic effects on chronic inflammation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires

    Directory of Open Access Journals (Sweden)

    M. B. Barbosa

    Full Text Available The paper discusses the application of High Strength Concrete (HSC technology for concrete production with the incorporation of Rice Husk Ash (RHA residues by replacing a bulk of the material caking and rubber tires with partial aggregate volume, assessing their influence on the mechanical properties and durability. For concrete with RHA and rubber, it was possible to reduce the brittleness by increasing the energy absorbing capacity. With respect to abrasion, the RHA and rubber concretes showed lower mass loss than the concrete without residues, indicating that this material is attractive to be used in paving. It is thus hoped that these residues may represent a technological and ecological alternative for the production of concrete in construction works.

  9. Auxin-dependent microtubule responses and seedling development are affected in a rice mutant resistant to EPC

    International Nuclear Information System (INIS)

    Nick, P.; Yatou, O.; Furuya, M.; Lambert, A.M.

    1994-01-01

    Mutants in rice (Oryza sativa L. cv. japonica) were used to study the role of the cytoskeleton in signal-dependent morphogenesis. Mutants obtained by gamma ray irradiation were selected that failed to show inhibition of coleoptile elongation by the anti microtubular drug ethyl-N-phenylcarbamate (EPC). The mutation EPC-Resistant 31 (ER31), isolated from such a screen, caused lethality in putatively homozygous embryos. Heterozygotes exhibited drug resistance, impaired development of crown roots, and characteristic changes in the pattern of cell elongation: cell elongation was enhanced in mesocotyls and leaf sheaths, but inhibited in coleoptiles. The orientation of cortical microtubules changed correspondingly: for etiolated seedlings, compared with the wild-type, they were more transverse with respect to the long cell axis in mesocotyls and leaf sheaths, but more longitudinal in coleoptiles. In mutant coleoptiles, in contrast to wild-type, microtubules did not reorient in response to auxin, and their response to microtubule-eliminating and microtubule-stabilizing drugs was conspicuously reduced. In contrast, they responded normally to other stimuli such as gibberellins or red light. Auxin sensitivity as assayed by the dose-response for callus induction did not show any significant differences between wild-type and mutant. The mutant phenotype is interpreted in terms of an interrupted link between auxin-triggered signal transduction and microtubule reorientation. (author)

  10. Does Nilaparvata lugens gain tolerance to rice resistance genes through conspecifics at shared feeding sites?

    NARCIS (Netherlands)

    Ferrater, Jedeliza B.; Horgan, Finbarr G.

    2016-01-01

    This study examines the possibility of horizontal and vertical transmission of virulence (the ability to tolerate a given resistant plant or resistance gene) between individuals from brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), populations with distinct feeding abilities

  11. Map-based Cloning and Characterization of the BPH18 Gene from Wild Rice Conferring Resistance to Brown Planthopper (BPH) Insect Pest.

    Science.gov (United States)

    Ji, Hyeonso; Kim, Sung-Ryul; Kim, Yul-Ho; Suh, Jung-Pil; Park, Hyang-Mi; Sreenivasulu, Nese; Misra, Gopal; Kim, Suk-Man; Hechanova, Sherry Lou; Kim, Hakbum; Lee, Gang-Seob; Yoon, Ung-Han; Kim, Tae-Ho; Lim, Hyemin; Suh, Suk-Chul; Yang, Jungil; An, Gynheung; Jena, Kshirod K

    2016-09-29

    Brown planthopper (BPH) is a phloem sap-sucking insect pest of rice which causes severe yield loss. We cloned the BPH18 gene from the BPH-resistant introgression line derived from the wild rice species Oryza australiensis. Map-based cloning and complementation test revealed that the BPH18 encodes CC-NBS-NBS-LRR protein. BPH18 has two NBS domains, unlike the typical NBS-LRR proteins. The BPH18 promoter::GUS transgenic plants exhibited strong GUS expression in the vascular bundles of the leaf sheath, especially in phloem cells where the BPH attacks. The BPH18 proteins were widely localized to the endo-membranes in a cell, including the endoplasmic reticulum, Golgi apparatus, trans-Golgi network, and prevacuolar compartments, suggesting that BPH18 may recognize the BPH invasion at endo-membranes in phloem cells. Whole genome sequencing of the near-isogenic lines (NILs), NIL-BPH18 and NIL-BPH26, revealed that BPH18 located at the same locus of BPH26. However, these two genes have remarkable sequence differences and the independent NILs showed differential BPH resistance with different expression patterns of plant defense-related genes, indicating that BPH18 and BPH26 are functionally different alleles. These findings would facilitate elucidation of the molecular mechanism of BPH resistance and the identified novel alleles to fast track breeding BPH resistant rice cultivars.

  12. Mapping and pyramiding of two major genes for resistance to the brown planthopper (Nilaparvata lugens [Stål]) in the rice cultivar ADR52.

    Science.gov (United States)

    Myint, Khin Khin Marlar; Fujita, Daisuke; Matsumura, Masaya; Sonoda, Tomohiro; Yoshimura, Atsushi; Yasui, Hideshi

    2012-02-01

    The brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most serious and destructive pests of rice, and can be found throughout the rice-growing areas of Asia. To date, more than 24 major BPH-resistance genes have been reported in several Oryza sativa ssp. indica cultivars and wild relatives. Here, we report the genetic basis of the high level of BPH resistance derived from an Indian rice cultivar, ADR52, which was previously identified as resistant to the whitebacked planthopper (Sogatella furcifera [Horváth]). An F(2) population derived from a cross between ADR52 and a susceptible cultivar, Taichung 65 (T65), was used for quantitative trait locus (QTL) analysis. Antibiosis testing showed that multiple loci controlled the high level of BPH resistance in this F(2) population. Further linkage analysis using backcross populations resulted in the identification of BPH-resistance (antibiosis) gene loci from ADR52. BPH25 co-segregated with marker S00310 on the distal end of the short arm of chromosome 6, and BPH26 co-segregated with marker RM5479 on the long arm of chromosome 12. To characterize the virulence of the most recently migrated BPH strain in Japan, preliminary near-isogenic lines (pre-NILs) and a preliminary pyramided line (pre-PYL) carrying BPH25 and BPH26 were evaluated. Although both pre-NILs were susceptible to the virulent BPH strain, the pre-PYL exhibited a high level of resistance. The pyramiding of resistance genes is therefore likely to be effective for increasing the durability of resistance against the new virulent BPH strain in Japan.

  13. Effects of water-saving irrigation practices and drought resistant rice variety on greenhouse gas emissions from a no-till paddy in the central lowlands of China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Ge, Junzhu; Tian, Shaoyang; Li, Shuya [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Nguy-Robertson, Anthony L. [Center for Advanced Land Management Information Technologies, School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583-0973 (United States); Zhan, Ming, E-mail: zhanming@mail.hzau.edu.cn [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Cao, Cougui, E-mail: ccgui@mail.hzau.edu.cn [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2015-02-01

    As pressure on water resources increases, alternative practices to conserve water in paddies have been developed. Few studies have simultaneously examined the effectiveness of different water regimes on conserving water, mitigating greenhouse gases (GHG), and maintaining yields in rice production. This study, which was conducted during the drought of 2013, examined all three factors using a split-plot experiment with two rice varieties in a no-till paddy managed under three different water regimes: 1) continuous flooding (CF), 2) flooded and wet intermittent irrigation (FWI), and 3) flooded and dry intermittent irrigation (FDI). The Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions were measured using static chamber-gas measurements, and the carbon dioxide (CO{sub 2}) emissions were monitored using a soil CO{sub 2} flux system (LI-8100). Compared with CF, FWI and FDI irrigation strategies reduced CH{sub 4} emissions by 60% and 83%, respectively. In contrast, CO{sub 2} and N{sub 2}O fluxes increased by 65% and 9%, respectively, under FWI watering regime and by 104% and 11%, respectively, under FDI managed plots. Although CO{sub 2} and N{sub 2}O emissions increased, the global warming potential (GWP) and greenhouse gas intensity (GHGI) of all three GHG decreased by up to 25% and 29% (p < 0.01), respectively, using water-saving irrigation strategies. The rice variety also affected yields and GHG emissions in response to different water regimes. The drought-resistance rice variety (HY3) was observed to maintain yields, conserve water, and reduce GHG under the FWI irrigation management compared with the typical variety (FYY299) planted in the region. The FYY299 only had significantly lower GWP and GHGI when the yield was reduced under FDI water regime. In conclusion, FWI irrigation strategy could be an effective option for simultaneously saving water and mitigating GWP without reducing rice yields using drought-resistant rice varieties, such as HY3

  14. Agronomic characters and lodging resistance of plant height mutants of rice

    International Nuclear Information System (INIS)

    Zhang Zhonggui; Wu Yuejin; Liu Binmei; Xu Xue; Zhang Lili; Wang Min

    2010-01-01

    Fourteen plant height mutants of Nipponbare were used to study the effect of plant height on the agronomic characters and lodging resistance. The results indicated that the plant height was positively correlated with spike length, third internode length, height of gravity center, fresh weight of main stem, dry weight of main stem, thousand-grain weight, grain-yield per plant and biological yield, and the second internode length. Meanwhile, plant height played an important role in lodging resistance, it was significantly positively correlated with lodging index and negatively correlated with bending moment and culm type index. The correlation between agronomic characters and lodging resistance showed that several agronomic characters had strong impact on the lodging resistance, such as spike length, height of gravity center, basal internode length ( first and second internode), fresh and dry weight of main stem, dry weight of basal internode, seed setting, thousand-grain weight, grain-weight per plant and biological yield. (authors)

  15. Physiological studies on photochemical oxidants injury in rice plants. I. Varietal difference of abscisic acid content and its relation to the resistance to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y.H.; Nakamura, H.; Ota, Y.

    1980-01-01

    In order to determine the abscisic acid relationships in the resistance of the rice plants to ozone, endogeneous abscisic acid content in varieties with different sensitivity to ozone was examined. The cultivars differed in their visible injury to ozone fumigation. Nipponbare and Jinheung were more sensitive than Tongil, Milyang No. 23 and Te-tep. Endogeneous abscisic acid content in the resistant variety (Tongil) was higher than in the sensitive one (Nipponbare). Visible injury caused by ozone fumigation was decreased by application of abscisic acid. Abscisic acid content in rice cultivars was found to increase differently depending on varieties response to ozone fumigation (0.3 ppM for 3 hours). The increase of abscisic acid content caused by ozone fumigation was higher in Nipponbare than in Tongil, although the endogeneous level of abscisic acid was higher in Tongil than Nipponbare.

  16. Construction of Double Right-Border Binary Vector Carrying Non-Host Gene Rxol Resistant to Bacterial Leaf Streak of Rice

    Institute of Scientific and Technical Information of China (English)

    Xu Mei-rong; XIA Zhi-hui; ZHAI Wen-xue; XU Jian-long; ZHOU Yong-li; LI Zhi-kang

    2008-01-01

    Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxol was digested with Sca Ⅰ and NgoM Ⅳ and the double right-border binary vector pMNDRBBin6 was digested with Hpa Ⅰ and Xma Ⅰ.pMNDRBBin6 carrying the gene Rxol was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxol gene had been cloned into pMNDRBBin6. This double right-border binary vector,named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation.

  17. Lightweight Heat Resistant Geopolymer-based Materials Synthesized from Red Mud and Rice Husk Ash Using Sodium Silicate Solution as Alkaline Activator

    Directory of Open Access Journals (Sweden)

    Hoc Thang Nguyen

    2017-01-01

    Full Text Available Geopolymer is an inorganic polymer composite with potentials to replace Ordinary Portland Cement (OPC-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in our study, the raw materials we used are red mud and rice husk ash, which are are industrial and agricultural wastes that need to be managed to reduce their impact to the environment. The red mud and rice husk ash combined with sodium silicate (water glass solution were mixed to form geopolymer materials. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000°C for 2 hours. Results suggest high heat resistance with an increase of compressive strength after exposed at high temperature.

  18. Improving Blast Resistance of a Thermo-Sensitive Genic Male Sterile Rice Line GD-8S by Molecular Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Wu-ge LIU

    2008-09-01

    Full Text Available The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%. On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.

  19. Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

    Science.gov (United States)

    Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-08-01

    Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Characterization of the beta-carotene hydroxylase gene DSM2 conferring drought and oxidative stress resistance by increasing xanthophylls and abscisic acid synthesis in rice.

    Science.gov (United States)

    Du, Hao; Wang, Nili; Cui, Fei; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2010-11-01

    Drought is a major limiting factor for crop production. To identify critical genes for drought resistance in rice (Oryza sativa), we screened T-DNA mutants and identified a drought-hypersensitive mutant, dsm2. The mutant phenotype was caused by a T-DNA insertion in a gene encoding a putative β-carotene hydroxylase (BCH). BCH is predicted for the biosynthesis of zeaxanthin, a carotenoid precursor of abscisic acid (ABA). The amounts of zeaxanthin and ABA were significantly reduced in two allelic dsm2 mutants after drought stress compared with the wild type. Under drought stress conditions, the mutant leaves lost water faster than the wild type and the photosynthesis rate, biomass, and grain yield were significantly reduced, whereas malondialdehyde level and stomata aperture were increased in the mutant. The mutant is also hypersensitive to oxidative stresses. The mutant had significantly lower maximal efficiency of photosystem II photochemistry and nonphotochemical quenching capacity than the wild type, indicating photoinhibition in photosystem II and decreased capacity for eliminating excess energy by thermal dissipation. Overexpression of DSM2 in rice resulted in significantly increased resistance to drought and oxidative stresses and increases of the xanthophylls and nonphotochemical quenching. Some stress-related ABA-responsive genes were up-regulated in the overexpression line. DSM2 is a chloroplast protein, and the response of DSM2 to environmental stimuli is distinctive from the other two BCH members in rice. We conclude that the DSM2 gene significantly contributes to control of the xanthophyll cycle and ABA synthesis, both of which play critical roles in the establishment of drought resistance in rice.

  1. A resistance locus in the American heirloom rice variety Carolina Gold Select is triggered by TAL effectors with diverse predicted targets and is effective against African strains of Xanthomonas oryzae pv. oryzicola.

    Science.gov (United States)

    Triplett, Lindsay R; Cohen, Stephen P; Heffelfinger, Christopher; Schmidt, Clarice L; Huerta, Alejandra I; Tekete, Cheick; Verdier, Valerie; Bogdanove, Adam J; Leach, Jan E

    2016-09-01

    The rice pathogens Xanthomonas oryzae pathovar (pv.) oryzae and pv. oryzicola produce numerous transcription activator-like (TAL) effectors that increase bacterial virulence by activating expression of host susceptibility genes. Rice resistance mechanisms against TAL effectors include polymorphisms that prevent effector binding to susceptibility gene promoters, or that allow effector activation of resistance genes. This study identifies, in the heirloom variety Carolina Gold Select, a third mechanism of rice resistance involving TAL effectors. This resistance manifests through strong suppression of disease development in response to diverse TAL effectors from both X. oryzae pathovars. The resistance can be triggered by an effector with only 3.5 central repeats, is independent of the composition of the repeat variable di-residues that determine TAL effector binding specificity, and is independent of the transcriptional activation domain. We determined that the resistance is conferred by a single dominant locus, designated Xo1, that maps to a 1.09 Mbp fragment on chromosome 4. The Xo1 interval also confers complete resistance to the strains in the African clade of X. oryzae pv. oryzicola, representing the first dominant resistance locus against bacterial leaf streak in rice. The strong phenotypic similarity between the TAL effector-triggered resistance conferred by Xo1 and that conferred by the tomato resistance gene Bs4 suggests that monocots and dicots share an ancient or convergently evolved mechanism to recognize analogous TAL effector epitopes. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  2. Transcriptional profiling of rice treated with MoHrip1 reveal the function of protein elicitor in enhancement of disease resistance and plant growth

    Directory of Open Access Journals (Sweden)

    Shun Lv

    2016-12-01

    Full Text Available MoHrip1 is a protein elicitor isolated from Magnaporthe oryzae and was found to induce blast-resistance in rice. To investigate the comprehensive functions of MoHrip1, next-generation sequencing (NGS-based digital gene expression (DGE profiling was performed to collect the transcriptional data of differentially expressed genes induced by MoHrip1. A total of 308 genes were identified with differential expression, and 80 genes were predicted to be induced specifically by MoHrip1. Among these 308 genes, a series of genes associated with the salicylic acid (SA pathway, phytoalexin, transcription factors and pathogen-related proteins were identified. Both the SA signaling pathway and the gibberellin (GA pathway were activated, while the jasmonic acid (JA signaling pathway was repressed. The contents of endogenous SA and GA and the morphological characteristics of the rice after treatment were measured to provide evidence supporting the predictions made based on the DGE data. The 80 genes mentioned above might be candidate genes for studying interactions with MoHrip1. The transcriptional data provided global effect information in rice induced by MoHrip1, and all the results demonstrated that MoHrip1 could induce pathogen resistance and promote plant growth by regulating the contents of SA and GA directly or indirectly.

  3. Analysis of DNA methylation related to rice adult plant resistance to bacterial blight based on methylation-sensitive AFLP (MSAP) analysis.

    Science.gov (United States)

    Sha, A H; Lin, X H; Huang, J B; Zhang, D P

    2005-07-01

    DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. The rice cultivar Wase Aikoku 3 becomes resistant to the blight pathogen Xanthomonas oryzae pv. oryzae at the adult stage. Using methylation-sensitive amplified polymorphism (MSAP) analysis, we compared the patterns of cytosine methylation in seedlings and adult plants of the rice cultivar Wase Aikoku 3 that had been inoculated with the pathogen Xanthomonas oryzae pv. oryzae, subjected to mock inoculation or left untreated. In all, 2000 DNA fragments, each representing a recognition site cleaved by either or both of two isoschizomers, were amplified using 60 pairs of selective primers. A total of 380 sites were found to be methylated. Of these, 45 showed differential cytosine methylation among the seedlings and adult plants subjected to different treatments, and overall levels of methylation were higher in adult plants than in seedlings. All polymorphic fragments were sequenced, and six showed homology to genes that code for products of known function. Northern analysis of three fragments indicated that their expression varied with methylation pattern, with hypermethylation being correlated with repression of transcription, as expected. The results suggest that significant differences in cytosine methylation exist between seedlings and adult plants, and that hypermethylation or hypomethylation of specific genes may be involved in the development of adult plant resistance (APR) in rice plants.

  4. Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

    2017-12-01

    The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

  5. Transcriptional Profiling of Rice Treated with MoHrip1 Reveal the Function of Protein Elicitor in Enhancement of Disease Resistance and Plant Growth.

    Science.gov (United States)

    Lv, Shun; Wang, Zhenzhen; Yang, Xiufen; Guo, Lihua; Qiu, Dewen; Zeng, Hongmei

    2016-01-01

    MoHrip1 is a protein elicitor isolated from Magnaporthe oryzae and was found to induce blast-resistance in rice. To investigate the comprehensive functions of MoHrip1, next-generation sequencing (NGS)-based digital gene expression (DGE) profiling was performed to collect the transcriptional data of differentially expressed genes (DEGs) induced by MoHrip1. A total of 308 genes were identified with differential expression, and 80 genes were predicted to be induced specifically by MoHrip1. Among these 308 genes, a series of genes associated with the salicylic acid (SA) pathway, phytoalexin, transcription factors, and pathogen-related proteins were identified. Both the SA signaling pathway and the gibberellin (GA) pathway were activated, while the jasmonic acid (JA) signaling pathway was repressed. The contents of endogenous SA and GA and the morphological characteristics of the rice after treatment were measured to provide evidence supporting the predictions made based on the DGE data. The 80 genes mentioned above might be candidate genes for studying interactions with MoHrip1. The transcriptional data provided global effect information in rice induced by MoHrip1, and all the results demonstrated that MoHrip1 could induce pathogen resistance and promote plant growth by regulating the contents of SA and GA directly or indirectly.

  6. Avirulence (AVR) Gene-Based Diagnosis Complements Existing Pathogen Surveillance Tools for Effective Deployment of Resistance (R) Genes Against Rice Blast Disease.

    Science.gov (United States)

    Selisana, S M; Yanoria, M J; Quime, B; Chaipanya, C; Lu, G; Opulencia, R; Wang, G-L; Mitchell, T; Correll, J; Talbot, N J; Leung, H; Zhou, B

    2017-06-01

    Avirulence (AVR) genes in Magnaporthe oryzae, the fungal pathogen that causes the devastating rice blast disease, have been documented to be major targets subject to mutations to avoid recognition by resistance (R) genes. In this study, an AVR-gene-based diagnosis tool for determining the virulence spectrum of a rice blast pathogen population was developed and validated. A set of 77 single-spore field isolates was subjected to pathotype analysis using differential lines, each containing a single R gene, and classified into 20 virulent pathotypes, except for 4 isolates that lost pathogenicity. In all, 10 differential lines showed low frequency (95%), inferring the effectiveness of R genes present in the respective differential lines. In addition, the haplotypes of seven AVR genes were determined by polymerase chain reaction amplification and sequencing, if applicable. The calculated frequency of different AVR genes displayed significant variations in the population. AVRPiz-t and AVR-Pii were detected in 100 and 84.9% of the isolates, respectively. Five AVR genes such as AVR-Pik-D (20.5%) and AVR-Pik-E (1.4%), AVRPiz-t (2.7%), AVR-Pita (0%), AVR-Pia (0%), and AVR1-CO39 (0%) displayed low or even zero frequency. The frequency of AVR genes correlated almost perfectly with the resistance frequency of the cognate R genes in differential lines, except for International Rice Research Institute-bred blast-resistant lines IRBLzt-T, IRBLta-K1, and IRBLkp-K60. Both genetic analysis and molecular marker validation revealed an additional R gene, most likely Pi19 or its allele, in these three differential lines. This can explain the spuriously higher resistance frequency of each target R gene based on conventional pathotyping. This study demonstrates that AVR-gene-based diagnosis provides a precise, R-gene-specific, and differential line-free assessment method that can be used for determining the virulence spectrum of a rice blast pathogen population and for predicting the

  7. A Nucleotide Phosphatase Activity in the Nucleotide Binding Domain of an Orphan Resistance Protein from Rice*

    Science.gov (United States)

    Fenyk, Stepan; de San Eustaquio Campillo, Alba; Pohl, Ehmke; Hussey, Patrick J.; Cann, Martin J.

    2012-01-01

    Plant resistance proteins (R-proteins) are key components of the plant immune system activated in response to a plethora of different pathogens. R-proteins are P-loop NTPase superfamily members, and current models describe their main function as ATPases in defense signaling pathways. Here we show that a subset of R-proteins have evolved a new function to combat pathogen infection. This subset of R-proteins possesses a nucleotide phosphatase activity in the nucleotide-binding domain. Related R-proteins that fall in the same phylogenetic clade all show the same nucleotide phosphatase activity indicating a conserved function within at least a subset of R-proteins. R-protein nucleotide phosphatases catalyze the production of nucleoside from nucleotide with the nucleotide monophosphate as the preferred substrate. Mutation of conserved catalytic residues substantially reduced activity consistent with the biochemistry of P-loop NTPases. Kinetic analysis, analytical gel filtration, and chemical cross-linking demonstrated that the nucleotide-binding domain was active as a multimer. Nuclear magnetic resonance and nucleotide analogues identified the terminal phosphate bond as the target of a reaction that utilized a metal-mediated nucleophilic attack by water on the phosphoester. In conclusion, we have identified a group of R-proteins with a unique function. This biochemical activity appears to have co-evolved with plants in signaling pathways designed to resist pathogen attack. PMID:22157756

  8. A nucleotide phosphatase activity in the nucleotide binding domain of an orphan resistance protein from rice.

    Science.gov (United States)

    Fenyk, Stepan; Campillo, Alba de San Eustaquio; Pohl, Ehmke; Hussey, Patrick J; Cann, Martin J

    2012-02-03

    Plant resistance proteins (R-proteins) are key components of the plant immune system activated in response to a plethora of different pathogens. R-proteins are P-loop NTPase superfamily members, and current models describe their main function as ATPases in defense signaling pathways. Here we show that a subset of R-proteins have evolved a new function to combat pathogen infection. This subset of R-proteins possesses a nucleotide phosphatase activity in the nucleotide-binding domain. Related R-proteins that fall in the same phylogenetic clade all show the same nucleotide phosphatase activity indicating a conserved function within at least a subset of R-proteins. R-protein nucleotide phosphatases catalyze the production of nucleoside from nucleotide with the nucleotide monophosphate as the preferred substrate. Mutation of conserved catalytic residues substantially reduced activity consistent with the biochemistry of P-loop NTPases. Kinetic analysis, analytical gel filtration, and chemical cross-linking demonstrated that the nucleotide-binding domain was active as a multimer. Nuclear magnetic resonance and nucleotide analogues identified the terminal phosphate bond as the target of a reaction that utilized a metal-mediated nucleophilic attack by water on the phosphoester. In conclusion, we have identified a group of R-proteins with a unique function. This biochemical activity appears to have co-evolved with plants in signaling pathways designed to resist pathogen attack.

  9. The pepper Bs4C proteins are localized to the endoplasmic reticulum (ER) membrane and confer disease resistance to bacterial blight in transgenic rice.

    Science.gov (United States)

    Wang, Jun; Zeng, Xuan; Tian, Dongsheng; Yang, Xiaobei; Wang, Lanlan; Yin, Zhongchao

    2018-03-30

    Transcription activator-like effector (TALE)-dependent dominant disease resistance (R) genes in plants, also referred to as executor R genes, are induced on infection by phytopathogenic bacteria of the genus Xanthomonas harbouring the corresponding TALE genes. Unlike the traditional R proteins, the executor R proteins do not determine the resistance specificity and may function broadly in different plant species. The executor R gene Bs4C-R in the resistant genotype PI 235047 of the pepper species Capsicum pubescens (CpBs4C-R) confers disease resistance to Xanthomonas campestris pv. vesicatoria (Xcv) harbouring the TALE genes avrBsP/avrBs4. In this study, the synthetic genes of CpBs4C-R and two other Bs4C-like genes, the susceptible allele in the genotype PI585270 of C. pubescens (CpBs4C-S) and the CaBs4C-R homologue gene in the cultivar 'CM334' of Capsicum annum (CaBs4C), were characterized in tobacco (Nicotiana benthamiana) and rice (Oryza sativa). The Bs4C genes induced cell death in N. benthamiana. The functional Bs4C-eCFP fusion proteins were localized to the endoplasmic reticulum (ER) membrane in the leaf epidermal cells of N. benthamiana. The Xa10 promoter-Bs4C fusion genes in transgenic rice conferred strain-specific disease resistance to Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight in rice, and were specifically induced by the Xa10-incompatible Xoo strain PXO99 A (pHM1avrXa10). The results indicate that the Bs4C proteins from pepper species function broadly in rice and the Bs4C protein-mediated cell death from the ER is conserved between dicotyledonous and monocotyledonous plants, which can be utilized to engineer novel and enhanced disease resistance in heterologous plants. © 2018 TEMASEK LIFE SCIENCES LABORATORY. MOLECULAR PLANT PATHOLOGY © 2018 JOHN WILEY & SONS LTD.

  10. The 9-lipoxygenase Osr9-LOX1 interacts with the 13-lipoxygenase-mediated pathway to regulate resistance to chewing and piercing-sucking herbivores in rice.

    Science.gov (United States)

    Zhou, Guoxin; Ren, Nan; Qi, Jingfeng; Lu, Jing; Xiang, Caiyu; Ju, Hongping; Cheng, Jiaan; Lou, Yonggen

    2014-09-01

    Oxylipins produced by the 13-lipoxygenase (LOX) have been reported to play an important role in plant defense responses to herbivores. Yet, the role of oxylipins produced by the 9-LOX pathway in this process remains largely unknown. Here we cloned a gene encoding a chloroplast-localized 9-LOX, Osr9-LOX1, from rice. Transcriptional analysis revealed that herbivore infestation, mechanical wounding and jasmonic acid (JA) treatment either repressed or did not enhance the level of Osr9-LOX1 transcripts at early stages but did at later stages, whereas salicylic acid (SA) treatment quickly increased the transcript level of Osr9-LOX1. Antisense expression of Osr9-lox1 (as-r9lox1) decreased the amount of wound-induced (Z)-3-hexenal but increased levels of striped stem borer (SSB)-induced linolenic acid, JA, SA and trypsin protease inhibitors. These changes were associated with increased resistance in rice to the larvae of the SSB Chilo suppressalis. In contrast, although no significant differences were observed in the duration of the nymph stage or the number of eggs laid by female adults between the brown planthopper (BPH) Nilaparvata lugens that fed on as-r9lox1 lines and BPH that fed on wild-type (WT) rice plants, the survival rate of BPH nymphs that fed on as-r9lox1 lines was higher than that of nymphs that fed on WT plants, possibly because of a higher JA level. The results demonstrate that Osr9-LOX1 plays an important role in regulating an herbivore-induced JA burst and cross-talk between JA and SA, and in controlling resistance in rice to chewing and phloem-feeding herbivores. © 2014 Scandinavian Plant Physiology Society.

  11. Resistance and tolerance to the brown planthopper, Nilaparvata lugens (Stål), in rice infested at different growth stages across a gradient of nitrogen applications.

    Science.gov (United States)

    Horgan, Finbarr G; Peñalver Cruz, Ainara; Bernal, Carmencita C; Ramal, Angelee Fame; Almazan, Maria Liberty P; Wilby, Andrew

    2018-03-01

    High resource availability can reduce anti-herbivore resistance (a plant's ability to defend against herbivores and reduce damage) in rice, Oryza sativa L, but may also increase tolerance (a plant's ability to withstand damage by, for example, compensatory growth). Through a series of greenhouse, screenhouse and field experiments, this study examines fitness (survival and development × reproduction) of the brown planthopper, Nilaparvata lugens (Stål), on resistant (IR62) and susceptible (IR22) rice varieties and age-related rice tolerance to planthopper damage under varying resource (nitrogenous fertilizer) availability. Planthoppers reared on IR62 in the greenhouse had lower fitness than planthoppers on IR22. IR62 became increasingly resistant as plants aged. IR22 was generally more tolerant of planthopper damage, and tolerance increased in IR22, but declined in IR62, as the plants aged. Rice plants infested at pre-tillering stages (3-4 leaf stage) in the screenhouse had greater losses to root, shoot and grain yield per unit weight of planthopper than plants infested at tillering stages, particularly in IR22. These trends were mainly due to the impact of planthoppers during pre-tillering stages and the length of exposure to the planthoppers. High nitrogen compromised IR62 resistance, particularly in tillering plants in the greenhouse study; however, high nitrogen did not increase planthopper biomass-density on IR62 in greenhouse or field cages. Tolerance to damage in IR62 at mid-tillering stages declined under increasing levels of nitrogen, but nitrogen increased tolerance during late-tillering stages. Planthopper damage to IR22 in field cages was severe and hopperburn (plant death) occurred in 83% of IR22 plants under high nitrogen (60-150 kg N ha -1 ). In contrast, despite planthopper infestations, damage to IR62 was low in field-grown plants and productivity (tillers, roots, shoots and grain) increased in IR62 under increasing nitrogen. Our results

  12. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    OpenAIRE

    Huangfu, Jiayi; Li, Jiancai; Li, Ran; Ye, Meng; Kuai, Peng; Zhang, Tongfang; Lou, Yonggen

    2016-01-01

    WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens) and by treatment with jasmonic acid (JA) or salic...

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

    International Nuclear Information System (INIS)

    Majd, F.; Rahimi, M.; Rezazadeh, M.

    2003-01-01

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

  14. Analysis of nucleotide diversity among alleles of the major bacterial blight resistance gene Xa27 in cultivars of rice (Oryza sativa) and its wild relatives.

    Science.gov (United States)

    Bimolata, Waikhom; Kumar, Anirudh; Sundaram, Raman Meenakshi; Laha, Gouri Shankar; Qureshi, Insaf Ahmed; Reddy, Gajjala Ashok; Ghazi, Irfan Ahmad

    2013-08-01

    Xa27 is one of the important R-genes, effective against bacterial blight disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo). Using natural population of Oryza, we analyzed the sequence variation in the functionally important domains of Xa27 across the Oryza species. DNA sequences of Xa27 alleles from 27 rice accessions revealed higher nucleotide diversity among the reported R-genes of rice. Sequence polymorphism analysis revealed synonymous and non-synonymous mutations in addition to a number of InDels in non-coding regions of the gene. High sequence variation was observed in the promoter region including the 5'UTR with 'π' value 0.00916 and 'θ w ' = 0.01785. Comparative analysis of the identified Xa27 alleles with that of IRBB27 and IR24 indicated the operation of both positive selection (Ka/Ks > 1) and neutral selection (Ka/Ks ≈ 0). The genetic distances of alleles of the gene from Oryza nivara were nearer to IRBB27 as compared to IR24. We also found the presence of conserved and null UPT (upregulated by transcriptional activator) box in the isolated alleles. Considerable amino acid polymorphism was localized in the trans-membrane domain for which the functional significance is yet to be elucidated. However, the absence of functional UPT box in all the alleles except IRBB27 suggests the maintenance of single resistant allele throughout the natural population.

  15. Expressing OsMPK4 Impairs Plant Growth but Enhances the Resistance of Rice to the Striped Stem Borer Chilo suppressalis

    Directory of Open Access Journals (Sweden)

    Xiaoli Liu

    2018-04-01

    Full Text Available Mitogen-activated protein kinases (MPKs play a central role not only in plant growth and development, but also in plant responses to abiotic and biotic stresses, including pathogens. Yet, their role in herbivore-induced plant defenses and their underlying mechanisms remain largely unknown. Here, we cloned a rice MPK gene, OsMPK4, whose expression was induced by mechanical wounding, infestation of the striped stem borer (SSB Chilo suppressalis, and treatment with jasmonic acid (JA, but not by treatment with salicylic acid (SA. The overexpression of OsMPK4 (oe-MPK4 enhanced constitutive and/or SSB-induced levels of JA, jasmonoyl-l-isoleucine (JA-Ile, ethylene (ET, and SA, as well as the activity of elicited trypsin proteinase inhibitors (TrypPIs, and reduced SSB performance. On the other hand, compared to wild-type plants, oe-MPK4 lines in the greenhouse showed growth retardation. These findings suggest that OsMPK4, by regulating JA-, ET-, and SA-mediated signaling pathways, functions as a positive regulator of rice resistance to the SSB and a negative regulator of rice growth.

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

    International Nuclear Information System (INIS)

    Cui Hairui; Wu Dianxing; Shen Shengquan; Shu Qingyao

    2004-01-01

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

  17. A putative gene sbe3-rs for resistant starch mutated from SBE3 for starch branching enzyme in rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Ruifang Yang

    Full Text Available Foods high in resistant starch (RS are beneficial to prevent various diseases including diabetes, colon cancers, diarrhea and chronic renal or hepatic diseases. Elevated RS in rice is important for public health since rice is a staple food for half of the world population. A japonica mutant 'Jiangtangdao 1' (RS = 11.67% was crossed with an indica cultivar 'Miyang 23' (RS = 0.41%. The mutant sbe3-rs that explained 60.4% of RS variation was mapped between RM6611 and RM13366 on chromosome 2 (LOD = 36 using 178 F(2 plants genotyped with 106 genome-wide polymorphic SSR markers. Using 656 plants from four F(3:4 families, sbe3-rs was fine mapped to a 573.3 Kb region between InDel 2 and InDel 6 using one STS, five SSRs and seven InDel markers. SBE3 which codes for starch branching enzyme was identified as a candidate gene within the putative region. Nine pairs of primers covering 22 exons were designed to sequence genomic DNA of the wild type for SBE3 and the mutant for sbe3-rs comparatively. Sequence analysis identified a missense mutation site where Leu-599 of the wild was changed to Pro-599 of the mutant in the SBE3 coding region. Because the point mutation resulted in the loss of a restriction enzyme site, sbe3-rs was not digested by a CAPS marker for SpeI site while SBE3 was. Co-segregation of the digestion pattern with RS content among 178 F(2 plants further supported sbe3-rs responsible for RS in rice. As a result, the CAPS marker could be used in marker-assisted breeding to develop rice cultivars with elevated RS which is otherwise difficult to accurately assess in crops. Transgenic technology should be employed for a definitive conclusion of the sbe3-rs.

  18. Cultivar difference in physicochemical properties of starches and flours from temperate rice of Indian Himalayas.

    Science.gov (United States)

    Mir, Shabir Ahmad; Bosco, Sowriappan John Don

    2014-08-15

    Starch and flour of seven temperate rice cultivars grown in Himalayan region were evaluated for composition, granule structure, crystallinity, Raman spectrometry, turbidity, swelling power, solubility, pasting properties and textural properties. The rice cultivars showed medium to high amylose content for starch (24.69-32.76%) and flour (17.78-24.86%). SKAU-382 showed the highest amount of amylose (32.76%). Rice starch showed polyhedral granule shapes and differences in their mean granule size (2.3-6.5 μm) were noted among the samples. The starch and flour samples showed type A-pattern with strong reflection at 15, 18, and 23. Pasting profile and textural analysis of rice starch and flour showed that all the cultivars differences, probably due to variation in amylose content. The present study can be used for identifying differences between rice genotypes for starch and flour quality and could provide guidance to possible industries for their end use. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Genetic analysis and fine mapping of a rice brown planthopper (Nilaparvata lugens Stål) resistance gene bph19(t).

    Science.gov (United States)

    Chen, J W; Wang, L; Pang, X F; Pan, Q H

    2006-04-01

    Genetic analysis and fine mapping of a resistance gene against brown planthopper (BPH) biotype 2 in rice was performed using two F(2) populations derived from two crosses between a resistant indica cultivar (cv.), AS20-1, and two susceptible japonica cvs., Aichi Asahi and Lijiangxintuanheigu. Insect resistance was evaluated using F(1) plants and the two F(2) populations. The results showed that a single recessive gene, tentatively designated as bph19(t), conditioned the resistance in AS20-1. A linkage analysis, mainly employing microsatellite markers, was carried out in the two F(2) populations through bulked segregant analysis and recessive class analysis (RCA), in combination with bioinformatics analysis (BIA). The resistance gene locus bph19(t) was finely mapped to a region of about 1.0 cM on the short arm of chromosome 3, flanked by markers RM6308 and RM3134, where one known marker RM1022, and four new markers, b1, b2, b3 and b4, developed in the present study were co-segregating with the locus. To physically map this locus, the bph19(t)-linked markers were landed on bacterial artificial chromosome or P1 artificial chromosome clones of the reference cv., Nipponbare, released by the International Rice Genome Sequencing Project. Sequence information of these clones was used to construct a physical map of the bph19(t) locus, in silico, by BIA. The bph19(t) locus was physically defined to an interval of about 60 kb. The detailed genetic and physical maps of the bph19(t) locus will facilitate marker-assisted gene pyramiding and cloning.

  20. Compositional analyses of white, brown and germinated forms of popular Malaysian rice to offer insight into the growing diet-related diseases

    Directory of Open Access Journals (Sweden)

    Bilyaminu Abubakar

    2018-04-01

    Full Text Available Diet-related metabolic diseases, and especially obesity, are metabolic disorders with multifactorial aetiologies. Diet has been a cornerstone in both the aetiology and management of this metabolic disorders. Rice, a staple food for over half of the world's population, could be exploited as part of the solution to check this menace which has been skyrocketing in the last decade. The present study investigated nine forms of rice from three widely grown Malaysian rice cultivars for in vitro and in vivo (glycaemic index and load properties that could translate clinically into a lower predisposition to diet-related diseases. The germinated brown forms of MRQ 74 and MR 84 rice cultivars had high amylose content percentages (25.7% and 25.0%, high relative percentage antioxidant scavenging abilities of 85.0% and 91.7%, relatively low glycaemic indices (67.6 and 64.3 and glycaemic load (32.3 and 30.1 values, and modest glucose uptake capabilities of 33.69% and 31.25%, respectively. The results show that all things being equal, rice cultivars that are germinated and high in amylose content when compared to their white and low amylose counterparts could translate into a lower predisposition to diet-related diseases from the dietary point of view in individuals who consume this cereal as a staple food. Keywords: Brown rice, Diet-related metabolic diseases, Germinated brown rice, White rice

  1. Screening of IR50 x Rathu Heenati F7 RILs and identification of SSR markers linked to brown planthopper (Nilaparvata lugens Stål) resistance in rice (Oryza sativa L.).

    Science.gov (United States)

    Kumari, Sanju; M Sheba, Jennifer; Marappan, Maheshwaran; Ponnuswamy, Shanmugasunderam; Seetharaman, Suresh; Pothi, Nagarajan; Subbarayalu, Mohankumar; Muthurajan, Raveendran; Natesan, Senthil

    2010-09-01

    Brown planthopper (Nilaparvata lugens Stål) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F(7) RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.

  2. Enhanced resistance to blast fungus in rice (Oryza sativa L.) by expressing the ribosome-inactivating protein α-momorcharin.

    Science.gov (United States)

    Qian, Qian; Huang, Lin; Yi, Rong; Wang, Shuzhen; Ding, Yi

    2014-03-01

    Rice blast caused by Magnaporthe grisea is one of the three major diseases that seriously affect the rice production. Alpha-momorcharin (α-MC), a ribosome-inactivating protein (RIP) isolated from Momordica charantia seeds, has antifungal effects in vitro. In this study, the α-MC gene was constitutively expressed under the control of the 2×35S promoter in transgenic rice (Oryza sativa L.) using an Agrobacterium tumefaciens-mediated method. The nine transgenic plants were obtained and confirmed by PCR and RT-PCR, and the four (B2, B4, B7 and B9) of them whose copy numbers were 1, 2, 3 and 3, respectively, were shown to express the α-MC protein by Western blot. The molecular weight of α-MC in transgenic plants was approximately 38 kDa larger than the purified α-MC protein (28 kDa) in vitro. When the confirmed T1 generations were inoculated with a suspension of M. grisea spores for ten days, the lesions on leaves of transgenic plants were much lesser than those found on wild type (WT). According to the criteria of International Rice Research Institute standard, the mean values for morbidity and disease index numbers were 29.8% and 14.9%, respectively, which were lower than for WT. It is unclear whether RIPs could impact plant fitness and however our results suggest that the α-MC protein is an effective antifungal protein preventing rice blast in transgenic rice. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Ectopic expression of ubiquitin-conjugating enzyme gene from wild rice, OgUBC1, confers resistance against UV-B radiation and Botrytis infection in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Jeon, En Hee; Pak, Jung Hun; Kim, Mi Jin; Kim, Hye Jeong; Shin, Sang Hyun; Lee, Jai Heon; Kim, Doh Hoon; Oh, Ju Sung; Oh, Boung-Jun; Jung, Ho Won; Chung, Young Soo

    2012-01-01

    Highlights: ► We isolated a novel E2 ubiquitin-conjugating enzyme from leaves of wild rice plants. ► The OgUBC1 was highly expressed in leaves treated with SA and UV-B radiation. ► The recombinant OgUBC1 has an enzymatic activity of E2 in vitro. ► The OgUBC1 could protect disruption of plant cells by UV-B radiation. ► OgUBC1 confers disease resistance and UV-B tolerance in transgenic Arabidopsis plants. -- Abstract: A previously unidentified gene encoding ubiquitin-conjugating enzyme was isolated from leaves of wild rice plant treated with wounding and microbe-associated molecular patterns. The OgUBC1 gene was composed of 148 amino acids and contained a typical active site and 21 ubiquitin thioester intermediate interaction residues and 4 E3 interaction residues. Both exogenous application of salicylic acid and UV-B irradiation triggered expression of OgUBC1 in leaves of wild rice. Recombinant OgUBC1 proteins bound to ubiquitins in vitro, proposing that the protein might act as E2 enzyme in planta. Heterologous expression of the OgUBC1 in Arabidopsis thaliana protected plants from cellular damage caused by an excess of UV-B radiation. A stable expression of chalcone synthase gene was detected in leaves of OgUBC1-expressing Arabidopsis, resulting in producing higher amounts of anthocyanin than those in wild-type Col-0 plants. Additionally, both pathogenesis-related gene1 and 5 were transcribed in the transgenic Arabidopsis in the absence of pathogen infection. The OgUBC1-expressing plants were resistant to the infection of Botrytis cinerea. Taken together, we suggested that the OgUBC1 is involved in ubiquitination process important for cellular response against biotic and abiotic stresses in plants.

  4. Ectopic expression of ubiquitin-conjugating enzyme gene from wild rice, OgUBC1, confers resistance against UV-B radiation and Botrytis infection in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, En Hee; Pak, Jung Hun; Kim, Mi Jin; Kim, Hye Jeong [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Shin, Sang Hyun [National Crop Experiment Station, Rural Development Administration, Suwon 441-100 (Korea, Republic of); Lee, Jai Heon; Kim, Doh Hoon; Oh, Ju Sung [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Oh, Boung-Jun [BioControl Center, Jeonnam 516-942 (Korea, Republic of); Jung, Ho Won, E-mail: hwjung@dau.ac.kr [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Chung, Young Soo, E-mail: chungys@dau.ac.kr [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer We isolated a novel E2 ubiquitin-conjugating enzyme from leaves of wild rice plants. Black-Right-Pointing-Pointer The OgUBC1 was highly expressed in leaves treated with SA and UV-B radiation. Black-Right-Pointing-Pointer The recombinant OgUBC1 has an enzymatic activity of E2 in vitro. Black-Right-Pointing-Pointer The OgUBC1 could protect disruption of plant cells by UV-B radiation. Black-Right-Pointing-Pointer OgUBC1 confers disease resistance and UV-B tolerance in transgenic Arabidopsis plants. -- Abstract: A previously unidentified gene encoding ubiquitin-conjugating enzyme was isolated from leaves of wild rice plant treated with wounding and microbe-associated molecular patterns. The OgUBC1 gene was composed of 148 amino acids and contained a typical active site and 21 ubiquitin thioester intermediate interaction residues and 4 E3 interaction residues. Both exogenous application of salicylic acid and UV-B irradiation triggered expression of OgUBC1 in leaves of wild rice. Recombinant OgUBC1 proteins bound to ubiquitins in vitro, proposing that the protein might act as E2 enzyme in planta. Heterologous expression of the OgUBC1 in Arabidopsis thaliana protected plants from cellular damage caused by an excess of UV-B radiation. A stable expression of chalcone synthase gene was detected in leaves of OgUBC1-expressing Arabidopsis, resulting in producing higher amounts of anthocyanin than those in wild-type Col-0 plants. Additionally, both pathogenesis-related gene1 and 5 were transcribed in the transgenic Arabidopsis in the absence of pathogen infection. The OgUBC1-expressing plants were resistant to the infection of Botrytis cinerea. Taken together, we suggested that the OgUBC1 is involved in ubiquitination process important for cellular response against biotic and abiotic stresses in plants.

  5. Influence of the agrochemicals used for rice and vegetable cultivation on insecticide resistance in malaria vectors in southern Côte d'Ivoire.

    Science.gov (United States)

    Chouaïbou, Mouhamadou S; Fodjo, Behi K; Fokou, Gilbert; Allassane, Ouattara F; Koudou, Benjamin G; David, Jean-Philippe; Antonio-Nkondjio, Christophe; Ranson, Hilary; Bonfoh, Bassirou

    2016-08-24

    Vector control can contribute to the development of resistance to insecticides in malaria vectors. As the swamps and wetlands used for some agricultural activities constitute productive breeding sites for many mosquito species, agricultural pest control may increase the selection pressure for insecticide resistance in mosquitoes. Understanding the use of agrochemicals by farmers is important to plan and initiate effective integrated pest and vector management interventions. A knowledge-attitude-practice study, using questionnaires, was undertaken with 102 rice farmers in Tiassalé and 106 vegetable farmers in Dabou (South Côte d'Ivoire) in order to generate information on pesticide usage. In addition, insecticide susceptibility bioassays were conducted using adult mosquitoes obtained from larvae collected within farms, and the persistence of agricultural pesticides in the farming environment, including sediment and mosquito breeding site water, was investigated by HPLC. Herbicides and insecticides appeared to be the most frequently used pesticides for both crops. Amino phosphonates (mostly glyphosate) represented the most used herbicides (45 % for rice up to 89 % for vegetables). Pyrethroids appeared to be the most used insecticides (accounting for 90 % of all the insecticide use reported). Approximately 75 % of respondents had not been to school and do not understand product labels. Only about 45 % of farmers respect the recommended pesticide dosage and about 10-15 % of pesticides used for rice and vegetable, respectively, are not recommended for these crops. As per WHO criteria, the mosquito local populations from the two localities were resistant to three of the four insecticides tested, as mortalities were less than 35 % for deltamethrin, DDT and bendiocarb. Higher susceptibility was observed for malathion, although the population was considered resistant in Dabou (80 % mortality) and susceptible in Tiassalé (98 % mortality). With the exception of

  6. Expression of BrD1, a plant defensin from Brassica rapa, confers resistance against brown planthopper (Nilaparvata lugens) in transgenic rices.

    Science.gov (United States)

    Choi, Man-Soo; Kim, Yul-Ho; Park, Hyang-Mi; Seo, Bo-Yoon; Jung, Jin-Kyo; Kim, Sun-Tae; Kim, Min-Chul; Shin, Dong-Bum; Yun, Hong-Tai; Choi, Im-Soo; Kim, Chung-Kon; Lee, Jang-Yong

    2009-08-31

    Plant defensins are small (5-10 kDa) basic peptides thought to be an important component of the defense pathway against fungal and/or bacterial pathogens. To understand the role of plant defensins in protecting plants against the brown planthopper, a type of insect herbivore, we isolated the Brassica rapa Defensin 1 (BrD1) gene and introduced it into rice (Oryza sativa L.) to produce stable transgenic plants. The BrD1 protein is homologous to other plant defensins and contains both an N-terminal endoplasmic reticulum signal sequence and a defensin domain, which are highly conserved in all plant defensins. Based on a phylogenetic analysis of the defensin domain of various plant defensins, we established that BrD1 belongs to a distinct subgroup of plant defensins. Relative to the wild type, transgenic rices expressing BrD1 exhibit strong resistance to brown planthopper nymphs and female adults. These results suggest that BrD1 exhibits insecticidal activity, and might be useful for developing cereal crop plants resistant to sap-sucking insects, such as the brown planthopper.

  7. Dynamics of multiple insecticide resistance in the malaria vector Anopheles gambiae in a rice growing area in South-Western Burkina Faso

    Directory of Open Access Journals (Sweden)

    Ouédraogo Jean-Bosco

    2008-09-01

    Full Text Available Abstract Background Insecticide resistance of the main malaria vector, Anopheles gambiae, has been reported in south-western Burkina Faso, West Africa. Cross-resistance to DDT and pyrethroids was conferred by alterations at site of action in the sodium channel, the Leu-Phe kdr mutation; resistance to organophosphates and carbamates resulted from a single point mutation in the oxyanion hole of the acetylcholinesterase enzyme designed as ace-1R. Methods An entomological survey was carried out during the rainy season of 2005 at Vallée du Kou, a rice growing area in south-western Burkina Faso. At the Vallée du Kou, both insecticide resistance mechanisms have been previously described in the M and S molecular forms of An. gambiae. This survey aimed i to update the temporal dynamics and the circumsporozoite infection rate of the two molecular forms M and S of An. gambiae ii to update the frequency of the Leu-Phe kdr mutation within these forms and finally iii to investigate the occurrence of the ace-1R mutation. Mosquitoes collected by indoor residual collection and by human landing catches were counted and morphologically identified. Species and molecular forms of An. gambiae, ace-1R and Leu-Phe kdr mutations were determined using PCR techniques. The presence of the circumsporozoite protein of Plasmodium falciparum was determined using ELISA. Results Anopheles gambiae populations were dominated by the M form. However the S form occurred in relative important proportion towards the end of the rainy season with a maximum peak in October at 51%. Sporozoite rates were similar in both forms. The frequency of the Leu-Phe kdr mutation in the S form reached a fixation level while it is still spreading in the M form. Furthermore, the ace-1R mutation prevailed predominately in the S form and has just started spreading in the M form. The two mutations occurred concomitantly both in M and S populations. Conclusion These results showed that the Vallée du Kou

  8. Marker-assisted pyramiding of brown planthopper (Nilaparvata lugens Stål) resistance genes Bph1 and Bph2 on rice chromosome 12.

    Science.gov (United States)

    Sharma, Prem N; Torii, Akihide; Takumi, Shigeo; Mori, Naoki; Nakamura, Chiharu

    2004-01-01

    Brown planthopper (BPH) (Nilaparvata lugens Stål) is a significant insect pest of rice (Oryza sativa L.). We constructed a gene-pyramided japonica line, in which two BPH resistance genes Bph1 and Bph2 on the long arm of chromosome 12 independently derived from two indica resistance lines were combined through the recombinant selection. The gene-pyramiding was achieved based on the previously constructed high-resolution linkage maps of the two genes. Two co-dominant and four dominant PCR-based markers flanking the loci were used to select for a homozygous recombinant line in a segregating population that was derived from a cross between the parental homozygous single-gene introgression lines. BPH bioassay showed that the resistance level of the pyramided line was equivalent to that of the Bph1-single introgression line, which showed a higher level of resistance than the Bph2-single introgression line. The pyramid line should provide a useful experimental means for studying the fine structure of the chromosomal region covering these two major BPH resistance genes.

  9. ENZYME RESISTANCE OF GENETICALLY MODIFIED STARCH POTATOES

    Directory of Open Access Journals (Sweden)

    A. Sh. Mannapova

    2015-01-01

    Full Text Available Here in this article the justification of expediency of enzyme resistant starch use in therapeutic food products is presented . Enzyme resistant starch is capable to resist to enzymatic hydrolysis in a small intestine of a person, has a low glycemic index, leads to decrease of postprandial concentration of glucose, cholesterol, triglycerides in blood and insulin reaction, to improvement of sensitivity of all organism to insulin, to increase in sense of fulness and to reduction of adjournment of fats. Resistant starch makes bifidogenшс impact on microflora of a intestine of the person, leads to increase of a quantity of lactobacillus and bifidobacterium and to increased production of butyric acid in a large intestine. In this regard the enzyme resistant starch is an important component in food for prevention and curing of human diseases such as diabetes, obesity, colitis, a cancer of large and direct intestine. One method is specified by authors for imitation of starch digestion in a human body. This method is based on the definition of an enzyme resistance of starch in vitro by its hydrolysis to glucose with application of a glucoamylase and digestive enzyme preparation Pancreatin. This method is used in researches of an enzyme resistance of starch, of genetically modified potato, high amylose corn starch Hi-Maize 1043 and HYLON VII (National Starch Food Innovation, USA, amylopectin and amylose. It is shown that the enzyme resistance of the starch emitted from genetically modified potatoes conforms to the enzyme resistance of the high amylose corn starch “Hi-Maize 1043 and HYLON VII starch”, (National Starch Food Innovation, the USA relating to the II type of enzyme resistant starch. It is established that amylopectin doesn't have the enzyme resistant properties. The results of researches are presented. They allow us to make the following conclusion: amylose in comparison with amylopectin possesses higher enzyme resistance and gives to

  10. Mechanism of Antibacterial Activities of a Rice Hull Smoke Extract (RHSE) Against Multidrug-Resistant Salmonella Typhimurium In Vitro and in Mice.

    Science.gov (United States)

    Kim, Sung Phil; Lee, Sang Jong; Nam, Seok Hyun; Friedman, Mendel

    2018-02-01

    The present study tested antibacterial activity of a rice hull smoke extract (RHSE) against a multidrug-resistant strain of Salmonella Typhimurium and examined its mode of suppressive action in vitro and in mice. In vitro studies showed that the minimum inhibitory concentration (MIC) value of RHSE was 1.29% (v/v). The inactivation was confirmed by complete loss of cell viability in the range of 10 4 to 10 7 colony forming units of the resistant Salmonella Typhimurium strain. Agarose and sodium dodecyl sulfate-polyacrylamide gel electrophoreses were used to evaluate the integrities of bacterial genomic DNA and total cellular protein profiles. The antibacterial action of RHSE results from a leakage of intracellular macromolecules following rupture of bacterial cells. Scanning electron microscopy of the cells shows that RHSE also induced deleterious morphological changes in the bacterial cell membrane of the pathogens. In vivo antibacterial activity of RHSE at a 1 × MIC concentration was examined in a bacterial gastroenteritis model using Balb/c mice orally infected with the Salmonella Typhimurium. The results show greatly decreased excretion of the bacteria into the feces and suppressed translocation of the bacteria to internal organs (cecum, mesenteric lymph node, spleen, and liver) compared with the infected mice not subjected to the RHSE treatment. Collectively, the present findings indicate that the mechanism of the antibacterial activities both in vitro and in the gastroenteritis environment of the animal model is the result of the direct disruption of cell structure, leading to cell death. RHSE has the potential to serve as a multifunctional food additive that might protect consumers against infections by antibiotic-resistant microorganisms. The rice hull derived liquid smoke has the potential to complement widely used wood-derived smoke as an antimicrobial flavor and health-promoting formulation for application in foods and feeds. Published 2017. This article

  11. Effects of temperature on growth and photosynthesis in the seedling stage of the sheath blight-resistant rice genotype 32R

    Directory of Open Access Journals (Sweden)

    Huynh Van Kiet

    2016-04-01

    Full Text Available The 32R rice genotype is resistant to sheath blight disease (ShB, with a high-yield potential. We examined effects of temperature on the plant responses of 32R in comparison with those of the ShB-susceptible rice genotype (29S and Nipponbare (Nb, a Japonica standard cultivar. The seedlings at the 4th leaf stage of rice genotypes were exposed to 14/14, 19/14, 25/20, 31/26, 37/32 and 37/37 °C (day/night for 5, 10 and 15 days. The dry weight, leaf area, photosynthesis, contents of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco and chlorophyll contents were examined. The dry weight showed lower in 32R than in 29S and Nb at a low temperature, and total dry weight correlated strongly with root dry weight and leaf area. The relative growth rate (RGR correlated strongly with the net assimilation rate (NAR. Rubisco, chlorophyll contents and the photosynthetic rates were limited at a low temperature and showed lower in 32R than in 29S and Nb. The strong correlations between Rubisco and the rates of maximum photosynthesis and initial slope were found in 32R, but not found in 29S and Nb. In addition, RGR and NAR of 32R correlated positively with Rubisco. These suggest that 32R contains traits of cold-sensitive genotypes that are related to limiting Rubisco at a low temperature, thus diminishing photosynthesis and limiting plant growth. Differences of growth among 32R, 29S and Nb were discussed in the relation of genotypes.

  12. Development of library preparation method able to correct gene expression levels in rice anther and isolate a trace expression gene mediated in cold-resistance

    International Nuclear Information System (INIS)

    Yamaguchi, Tomoya; Koike, Setsuo

    2000-01-01

    When cDNA library is prepared by a previously developed method, genes of which expression level is high are apt to be cloned at a high frequency, whereas genes of which expression level are low, are difficult to be cloned. A low-expression gene has been cloned at very low frequency. Therefore, the gene encoding the key enzyme that is involved in growth disturbance of rice pollen has not been identified. In this study, development of a library preparing method able to correct the expression level was attempted using highly sensitive detection method with radioisotope and some genes related to cold-resistance of rice were isolated. Double strand DNAs were synthesized using mRNA extract from rice anthers and annealed following heat-denaturation. It has been known that single strand DNA molecules abundantly existing in DNA solution can easily aggregate to form double strand DNA, but single stranded DNA molecules poor in the solution are apt to still remain as single strand after annealing. Thus, the amount of single strand DNA would be balanced in the solution between abundant DNA and poor DNA species. The authors succeeded to prepare a gene library including low and high expression genes at similar proportions. Moreover, spin trap method that allows RI labeling of DNA bound to latex particle, was developed to detect with high sensitivity, especially for genes that are expressed at low level. The present method could be used for recovery, detection and quantitative analysis of radiolabeled single strand DNA. Thus, it was demonstrated that the stage from tetrad sperm to small sperm might be easily affected by cold stress. The present results suggest that the expressions of β-1 and β-3 glucanase, which are involved in the release of small sperms following meiosis in the pollen formation, might be easily affected by cold stress. (M.N.)

  13. Development of library preparation method able to correct gene expression levels in rice anther and isolate a trace expression gene mediated in cold-resistance

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Tomoya; Koike, Setsuo [Tohoku National Agricultural Experiment Station, Morioka (Japan)

    2000-02-01

    When cDNA library is prepared by a previously developed method, genes of which expression level is high are apt to be cloned at a high frequency, whereas genes of which expression level are low, are difficult to be cloned. A low-expression gene has been cloned at very low frequency. Therefore, the gene encoding the key enzyme that is involved in growth disturbance of rice pollen has not been identified. In this study, development of a library preparing method able to correct the expression level was attempted using highly sensitive detection method with radioisotope and some genes related to cold-resistance of rice were isolated. Double strand DNAs were synthesized using mRNA extract from rice anthers and annealed following heat-denaturation. It has been known that single strand DNA molecules abundantly existing in DNA solution can easily aggregate to form double strand DNA, but single stranded DNA molecules poor in the solution are apt to still remain as single strand after annealing. Thus, the amount of single strand DNA would be balanced in the solution between abundant DNA and poor DNA species. The authors succeeded to prepare a gene library including low and high expression genes at similar proportions. Moreover, spin trap method that allows RI labeling of DNA bound to latex particle, was developed to detect with high sensitivity, especially for genes that are expressed at low level. The present method could be used for recovery, detection and quantitative analysis of radiolabeled single strand DNA. Thus, it was demonstrated that the stage from tetrad sperm to small sperm might be easily affected by cold stress. The present results suggest that the expressions of {beta}-1 and {beta}-3 glucanase, which are involved in the release of small sperms following meiosis in the pollen formation, might be easily affected by cold stress. (M.N.)

  14. Rice microstructure

    Science.gov (United States)

    An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...

  15. Effect of methyl salicylate (MeSA), an elicitor on growth, physiology and pathology of resistant and susceptible rice varieties.

    Science.gov (United States)

    Kalaivani, Kandaswamy; Kalaiselvi, Marimuthu Maruthi; Senthil-Nathan, Sengottayan

    2016-10-11

    Methyl salicylate (MeSA) is a volatile organic compound synthesized from salicylic acid (SA) a plant hormone that helps to fight against plant disease. Seed treatment with MeSA, is an encouraging method to the seed industry to produce more growth and yield. The aim of our study is to find out the growth, development and disease tolerance of rice seed treated with different concentrations of MeSA. Also the seed treatments were studied to determine whether they directly influenced seedling emergence and growth in rice (Oryza sativa L) cultivars 'IR 20, IR 50, IR 64, ASD 16, ASD 19 and ADT 46' under greenhouse condition. MeSA seed treatments at 25, 50, 75 and 100 mg/L significantly increased seedling emergence. Effects were stronger in IR 50, and IR 64 and the effects were dose dependent, although the relationship between dose and effect was not always linear. MeSA seed treated rice plant against bacterial blight were analyzed. Bacterial blight was more effectively controlled by the seed treated with 100 mg/L than others. These results suggest that seed treatment with MeSA alters plant physiology in ways that may be useful for crop production as well as protection.

  16. The Novel Kasugamycin 2′-N-Acetyltransferase Gene aac(2′)-IIa, Carried by the IncP Island, Confers Kasugamycin Resistance to Rice-Pathogenic Bacteria

    Science.gov (United States)

    Moriyama, Hiromitsu; Fukuhara, Toshiyuki

    2012-01-01

    Kasugamycin (KSM), a unique aminoglycoside antibiotic, has been used in agriculture for many years to control not only rice blast caused by the fungus Magnaporthe grisea but also rice bacterial grain and seedling rot or rice bacterial brown stripe caused by Burkholderia glumae or Acidovorax avenae subsp. avenae, respectively. Since both bacterial pathogens are seed-borne and cause serious injury to rice seedlings, the emergence of KSM-resistant B. glumae and A. avenae isolates highlights the urgent need to understand the mechanism of resistance to KSM. Here, we identified a novel gene, aac(2′)-IIa, encoding a KSM 2′-N-acetyltransferase from both KSM-resistant pathogens but not from KSM-sensitive bacteria. AAC(2′)-IIa inactivates KSM, although it reveals no cross-resistance to other aminoglycosides. The aac(2′)-IIa gene from B. glumae strain 5091 was identified within the IncP genomic island inserted into the bacterial chromosome, indicating the acquisition of this gene by horizontal gene transfer. Although excision activity of the IncP island and conjugational gene transfer was not detected under the conditions tested, circular intermediates containing the aac(2′)-IIa gene were detected. These results indicate that the aac(2′)-IIa gene had been integrated into the IncP island of a donor bacterial species. Molecular detection of the aac(2′)-IIa gene could distinguish whether isolates are resistant or susceptible to KSM. This may contribute to the production of uninfected rice seeds and lead to the effective control of these pathogens by KSM. PMID:22660700

  17. Identification of a Rice stripe necrosis virus resistance locus and yield component QTLs using Oryza sativa × O. glaberrima introgression lines

    Directory of Open Access Journals (Sweden)

    Prado Gustavo

    2010-01-01

    Full Text Available Abstract Background Developing new population types based on interspecific introgressions has been suggested by several authors to facilitate the discovery of novel allelic sources for traits of agronomic importance. Chromosome segment substitution lines from interspecific crosses represent a powerful and useful genetic resource for QTL detection and breeding programs. Results We built a set of 64 chromosome segment substitution lines carrying contiguous chromosomal segments of African rice Oryza glaberrima MG12 (acc. IRGC103544 in the genetic background of Oryza sativa ssp. tropical japonica (cv. Caiapó. Well-distributed simple-sequence repeats markers were used to characterize the introgression events. Average size of the substituted chromosomal segments in the substitution lines was about 10 cM and covered the whole donor genome, except for small regions on chromosome 2 and 4. Proportions of recurrent and donor genome in the substitution lines were 87.59% and 7.64%, respectively. The remaining 4.78% corresponded to heterozygotes and missing data. Strong segregation distortion was found on chromosomes 3 and 6, indicating the presence of interspecific sterility genes. To illustrate the advantages and the power of quantitative trait loci (QTL detection using substitution lines, a QTL detection was performed for scored traits. Transgressive segregation was observed for several traits measured in the population. Fourteen QTLs for plant height, tiller number per plant, panicle length, sterility percentage, 1000-grain weight and grain yield were located on chromosomes 1, 3, 4, 6 and 9. Furthermore, a highly significant QTL controlling resistance to the Rice stripe necrosis virus was located between SSR markers RM202-RM26406 (44.5-44.8 cM on chromosome 11. Conclusions Development and phenotyping of CSSL libraries with entire genome coverage represents a useful strategy for QTL discovery. Mapping of the RSNV locus represents the first identification

  18. OsMPK3 positively regulates the JA signaling pathway and plant resistance to a chewing herbivore in rice.

    Science.gov (United States)

    Wang, Qi; Li, Jiancai; Hu, Lingfei; Zhang, Tongfang; Zhang, Guren; Lou, Yonggen

    2013-07-01

    KEY MESSAGE : Silencing OsMPK3 decreased elicited JA levels, which subsequently reduced levels of herbivore-induced trypsin protease inhibitors (TrypPIs) and improved the performance of SSB larvae, but did not influence BPH. Mitogen-activated protein kinases (MPKs) are known to play an important role in plant defense by transferring biotic and abiotic signals into programmed cellular responses. However, their functions in the herbivore-induced defense response in rice remain largely unknown. Here, we identified a MPK3 gene from rice, OsMPK3, and found that its expression levels were up-regulated in response to infestation by the larvae of the striped stem borer (SSB) (Chilo suppressalis), to mechanical wounding and to treatment with jasmonic acid (JA), but not to infestation by the brown planthopper (BPH) Nilaparvata lugens or to treatment with salicylic acid. Moreover, mechanical wounding and SSB infestation induced the expression of OsMPK3 strongly and quickly, whereas JA treatment induced the gene more weakly and slowly. Silencing OsMPK3 (ir-mpk3) reduced the expression of the gene by 50-70 %, decreased elicited levels of JA and diminished the expression of a lipoxygenase gene OsHI-LOX and an allene oxide synthase gene OsAOS1. The reduced JA signaling in ir-mpk3 plants decreased the levels of herbivore-induced trypsin protease inhibitors (TrypPIs) and improved the performance of SSB larvae, but did not influence BPH. Our findings suggest that the gene OsMPK3 responds early in herbivore-induced defense and can be regulated by rice plants to activate a specific and appropriate defense response to different herbivores.

  19. Identification of a rice gene (Bph 1) conferring resistance to brown planthopper (Nilaparvata lugens Stal) using STS markers.

    Science.gov (United States)

    Kim, Suk-Man; Sohn, Jae-Keun

    2005-08-31

    This study was carried out to identify a high-resolution marker for a gene conferring resistance to brown planthopper (BPH) biotype 1, using japonica type resistant lines. Bulked segregant analyses were conducted using 520 RAPD primers to identify RAPD fragments linked to the BPH resistance gene. Eleven RAPDs were shown to be polymorphic amplicons between resistant and susceptible progeny. One of these primers, OPE 18, which amplified a 923 bp band tightly linked to resistance, was converted into a sequence-tagged-site (STS) marker. The STS marker, BpE18-3, was easily detectable as a dominant band with tight linkage (3.9cM) to Bph1. It promises to be useful as a marker for assisted selection of resistant progeny in backcross breeding programs to introgress the resistance gene into elite japonica cultivars.

  20. A correlation study of proximate composition, physical and cooking properties of new high yielding and disease resistant rice varieties

    Directory of Open Access Journals (Sweden)

    Nuzhat Rasool

    2015-12-01

    Full Text Available The present study was aimed to compare proximate composition, physical, and cooking properties of locally cultivated rice varieties of Kashmir division viz.; SR-1, K-448, and K-39. Various physiochemical properties were studied. The relationship between physical, proximate composition, and cooking properties was determined using Pearson’s correlation. Length–breadth (L/B ratio showed a significant positive correlation with kernel length and negative correlation with thousand kernel weight, with a correlation coefficient (r of 0.893 and −0.855, respectively, (p  0.05. Solid loss in gruel was observed to have a negative correlation with L/B ratio (r = −0.432, p > 0.05, water uptake ratio (r = −0.742, p < 0.05, and cooking time (r = −0.678, p < 0.05. The rice cultivars with higher cooking time showed lower gruel solid loss and vice versa. Water uptake was observed to be positively correlated with L/B ratio (r = 0.768, p < 0.05. Among all the cultivars studied, K-448 variety has potential for consumers’ preference and it could be used for breeding programs for the improvement of valuable grain quality traits.

  1. 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.

  2. Influences of the disease resistance conferred by the individual ...

    African Journals Online (AJOL)

    To research possible influences of the disease resistance conferred by different trans-resistance genes on the transgenic rice plants in their yields and grain quality, three transgenic rice lines, including two with the resistance genes Pi-d2 and Pi-d3, respectively, for rice blast, and one with the resistance gene Xa21 for rice ...

  3. Clustering of 18 Local Black Rice Base on Total Anthocyanin

    Directory of Open Access Journals (Sweden)

    Kristamtini Kristamtini

    2017-10-01

    Full Text Available Black rice has a high anthocyanin content in the pericarp layer, which provides a dark purple color. Anthocyanin serve as an antioxidant that control cholesterol level in the blood, prevent anemia, potentially improve the body's resistance to disease, improve damage to liver cells (hepatitis and chirrosis, prevent impaired kidney function, prevent cancer/tumors, slows down antiaging, and prevent atherosclerosis and cardiovascular disease. Exploration results at AIAT Yogyakarta, Indonesia from 2011 to 2014 obtained 18 cultivar of local black rice Indonesia. The names of the rice are related to the color (black, red or purple formed by anthocyanin deposits in the pericarp layer, seed coat or aleuron. The objective of the study was to classify several types of local black rice from explorations based on the total anthocyanin content. The study was conducted by clustering analyzing the total anthocyanin content of 18 local black rice cultivars in Indonesia. Cluster analysis of total anthocyanin content were done using SAS ver. 9.2. Clustering dendogram shows that there were 4 groups of black rice cultivars based on the total anthocyanin content. Group I consists of Melik black rice, Patalan black rice, Yunianto black rice, Muharjo black rice, Ngatijo black rice, short life of Tugiyo black rice, Andel hitam 1, Jlitheng, and Sragen black rice. Group II consists of Pari ireng, Magelang black hairy rice, Banjarnegara-Wonosobo black rice, and Banjarnegara black rice. Group III consists of NTT black rice, Magelang non hairy black rice, Sembada hitam, and longevity Tugiyo black rice. Group IV consist only one type of black rice namely Cempo ireng. The grouping result indicate the existence of duplicate names among the black rice namely Patalan with Yunianto black rice, and short life Tugiyo with Andel hitam 1 black rice.

  4. Rice production in relation to soil quality under different rice-based cropping systems

    Science.gov (United States)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P < 0.01) between rice plant parameters, rice yield and soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal

  5. Improvement of local varieties of rice (Oryza glaberrima) for resistance to shattering and grain quality by induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    Cisse, F; Dione, M; Kelly, S [Institute d` Economie Rurale, Station de Recherche Agronomique, Mopti (Mali)

    1997-12-01

    In Mali, a large area of rice is planted with the local rice, O. glaberrima which under conditions of low rainfall and flood water is more hardy to stress than the introduced O. sativa cultivars. A program to improve the local varieties of O. glaberrima by induced mutations was started in 1988. Ten local varieties were irradiated with 20 and 30 krad. In M{sub 4} of cv. `Gorbal`, irradiated with 20 krads, 13 variants were selected. Five of these were evaluated in M{sub 5} for their agronomic performance. The induced mutants in the remaining 9 varieties were highly sterile with 90% or more sterility in the M{sub 2} and M{sub 3}. Irradiation with 20-30 krad gave high survival (70-95%), and several mutants with white kernel were obtained from the red seeded types. Nearly two-third of the identified mutants had white caryopsis. There is better consumer acceptance of the white seeded type of rice than the red seeded varieties in Mali and the white seeded mutants may have an added premium in the market. The field performance of the M{sub 5} mutants was investigated. Preliminary results showed that some of mutants derived from cv. `Gorbal` were early in maturity and had more panicles per plant, but had a lower 1000-kernel weight, and did not differ from the parent in grain yield. Additional trials are planned to establish potential of the mutants for yield and quality. Three more cultivars of O. glaberrima - `Haira`, `Tombo` and `Yele` - were irradiated with 20 and 60 krads, and gave 75, 81 and 72% seed viability, respectively. M{sub 1} showed reduced plant height. Selection for non-shattering of grains shall be carried out in M{sub 2}. Any plants which are non-shattering but sterile shall be crossed with the parent to recover the mutant types. The taxonomic status of cv. `Gorbal` is not very clear. Isozyme patterns suggest that this cultivar may belong to O. sativa and not to O. glaberrima. To establish its taxonomic status, crosses shall be made with O. sativa and O

  6. Improvement of local varieties of rice (Oryza glaberrima) for resistance to shattering and grain quality by induced mutations

    International Nuclear Information System (INIS)

    Cisse, F.; Dione, M.; Kelly, S.

    1997-01-01

    In Mali, a large area of rice is planted with the local rice, O. glaberrima which under conditions of low rainfall and flood water is more hardy to stress than the introduced O. sativa cultivars. A program to improve the local varieties of O. glaberrima by induced mutations was started in 1988. Ten local varieties were irradiated with 20 and 30 krad. In M 4 of cv. 'Gorbal', irradiated with 20 krads, 13 variants were selected. Five of these were evaluated in M 5 for their agronomic performance. The induced mutants in the remaining 9 varieties were highly sterile with 90% or more sterility in the M 2 and M 3 . Irradiation with 20-30 krad gave high survival (70-95%), and several mutants with white kernel were obtained from the red seeded types. Nearly two-third of the identified mutants had white caryopsis. There is better consumer acceptance of the white seeded type of rice than the red seeded varieties in Mali and the white seeded mutants may have an added premium in the market. The field performance of the M 5 mutants was investigated. Preliminary results showed that some of mutants derived from cv. 'Gorbal' were early in maturity and had more panicles per plant, but had a lower 1000-kernel weight, and did not differ from the parent in grain yield. Additional trials are planned to establish potential of the mutants for yield and quality. Three more cultivars of O. glaberrima - 'Haira', 'Tombo' and 'Yele' - were irradiated with 20 and 60 krads, and gave 75, 81 and 72% seed viability, respectively. M 1 showed reduced plant height. Selection for non-shattering of grains shall be carried out in M 2 . Any plants which are non-shattering but sterile shall be crossed with the parent to recover the mutant types. The taxonomic status of cv. 'Gorbal' is not very clear. Isozyme patterns suggest that this cultivar may belong to O. sativa and not to O. glaberrima. To establish its taxonomic status, crosses shall be made with O. sativa and O. glaberrima. (author). 2 tabs

  7. Fine mapping of the rice Bph1 gene, which confers resistance to the brown planthopper (Nilaparvata lugens stal), and development of STS markers for marker-assisted selection.

    Science.gov (United States)

    Cha, Young-Soon; Ji, Hyeonso; Yun, Doh-Won; Ahn, Byoung-Ohg; Lee, Myung Chul; Suh, Seok-Cheol; Lee, Chun Seok; Ahn, Eok Keun; Jeon, Yong-Hee; Jin, Il-Doo; Sohn, Jae-Keun; Koh, Hee-Jong; Eun, Moo-Young

    2008-08-31

    The brown planthopper (BPH) is a major insect pest in rice, and damages these plants by sucking phloem-sap and transmitting viral diseases. Many BPH resistance genes have been identified in indica varieties and wild rice accessions, but none has yet been cloned. In the present study we report fine mapping of the region containing the Bph1 locus, which enabled us to perform marker-aided selection (MAS). We used 273 F8 recombinant inbred lines (RILs) derived from a cross between Cheongcheongbyeo, an indica type variety harboring Bph1 from Mudgo, and Hwayeongbyeo, a BPH susceptible japonica variety. By random amplification of polymorphic DNA (RAPD) analysis using 656 random 10-mer primers, three RAPD markers (OPH09, OPA10 and OPA15) linked to Bph1 were identified and converted to SCAR (sequence characterized amplified region) markers. These markers were found to be contained in two BAC clones derived from chromosome 12: OPH09 on OSJNBa0011B18, and both OPA10 and OPA15 on OSJNBa0040E10. By sequence analysis of ten additional BAC clones evenly distributed between OSJNBa0011B18 and OSJNBa0040E10, we developed 15 STS markers. Of these, pBPH4 and pBPH14 flanked Bph1 at distances of 0.2 cM and 0.8 cM, respectively. The STS markers pBPH9, pBPH19, pBPH20, and pBPH21 co-segregated with Bph1. These markers were shown to be very useful for marker-assisted selection (MAS) in breeding populations of 32 F6 RILs from a cross between Andabyeo and IR71190, and 32 F5 RILs from a cross between Andabyeo and Suwon452.

  8. Evaluation of nitric and acetic acid resistance of cement mortars containing high-volume black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2014-01-15

    This paper presents the performance of cement mortar containing black rice husk ash (BRHA) under nitric and acetic acid attacks. The BRHA, collected from an electrical generating power plant that uses rice husk as fuel, was ground using a grinding machine. The compressive strength loss, weight loss, and expansion of mortars under nitric and acetic acid attack were investigated. The test results of BRHA properties in accordance with the ASTM C 618 standard found that the optimal grinding time was 4 h as this achieved a Blaine fineness of 5370 cm(2)/g. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 20%, 30%, 40%, and 50% by weight of binder. The water-to-binder ratios were 0.55, 0.60, and 0.65. From test results, when the percentage replacements of BRHA in cement increased, it was observed that the strength loss and weight loss of mortars containing BRHA under acetic acid attack were higher than those of the mortars against nitric acid attack. It was found that, of the various BHRA mortars, the strength loss and weight loss due to nitric and acetic acid attacks were the lowest in the mortar with 10% BRHA replacement. For 10%, 20% and 30% BRHA replacements, the rate of expansion of the BRHA mortar decreased when compared with the control mortar. For the mortars with other percentage replacements of BRHA, the rate of expansion increased. Furthermore, the effective water-to-binder ratios of control and BRHA mortars were the primary factor for determining the durability of mortar mixed with BRHA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Genome-wide DNA polymorphisms in Kavuni, a traditional rice cultivar with nutritional and therapeutic properties.

    Science.gov (United States)

    Rathinasabapathi, Pasupathi; Purushothaman, Natarajan; Parani, Madasamy

    2016-05-01

    Although rice genome was sequenced in the year 2002, efforts in resequencing the large number of available accessions, landraces, traditional cultivars, and improved varieties of this important food crop are limited. We have initiated resequencing of the traditional cultivars from India. Kavuni is an important traditional rice cultivar from South India that attracts premium price for its nutritional and therapeutic properties. Whole-genome sequencing of Kavuni using Illumina platform and SNPs analysis using Nipponbare reference genome identified 1 150 711 SNPs of which 377 381 SNPs were located in the genic regions. Non-synonymous SNPs (62 708) were distributed in 19 251 genes, and their number varied between 1 and 115 per gene. Large-effect DNA polymorphisms (7769) were present in 3475 genes. Pathway mapping of these polymorphisms revealed the involvement of genes related to carbohydrate metabolism, translation, protein-folding, and cell death. Analysis of the starch biosynthesis related genes revealed that the granule-bound starch synthase I gene had T/G SNPs at the first intron/exon junction and a two-nucleotide combination, which were reported to favour high amylose content and low glycemic index. The present study provided a valuable genomics resource to study the rice varieties with nutritional and medicinal properties.

  10. Desempenho de populações híbridas F2 de arroz-vermelho (Oryza sativa com arroz transgênico (O. sativa resistente ao herbicida amonio-glufosinate Performance of F2 hybrid populations of red rice (Oryza sativa with ammonium-glufosinate-resistant transgenic rice (O. sativa

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2004-09-01

    -preto. Mesmo assim, os usuários dessa tecnologia deverão adotar, obrigatoriamente, medidas que evitem a possibilidade de cruzamento entre o arroz transgênico e o arroz-vermelho ou arroz-preto.Red rice is an important weed in paddy rice fields. The use of ammonium glufosinate - resistant genetically modified (GM rice cultivars is a viable alternative for controlling red rice in cultivated rice crops. The objective of this study was to evaluate the behavior of F2 hybrid population derivates of crossing between ammonium glufosinate - resistant GM rice and red rice. The F2 hybrid population derivates of crossing between GM rice and red rice are viable but do not present any apparent competitive advantage over red rice. The morphological characteristics of the F2 hybrid populations, such as tillering capacity, number of leaves produced and average plant height were partly reduced and partly unaffected by the introgression of the bar gene. The period between rice planting and 50% flowering increased in the red rice x GM rice F2 hybrids, compared to the parental red rice and GM rice. Average seed shattering rate in the four hybrid families was lower than in the red rice ecotypes, with such aspect also being unfavorable to the persistence of red rice in the environment. Seed dormancy of the hybrids was similar to that of the red rice ecotypes. However, management practices should be adopted to avoid crossing between transgenic rice and red rice.

  11. In utero exposure to germinated brown rice and its oryzanol-rich extract attenuated high fat diet-induced insulin resistance in F1 generation of rats.

    Science.gov (United States)

    Adamu, Hadiza Altine; Imam, Mustapha Umar; Ooi, Der-Jiun; Esa, Norhaizan Mohd; Rosli, Rozita; Ismail, Maznah

    2017-01-21

    The development of insulin resistance is multifactorial, with maternal pre- and postnatal nutrition having significant influences. In this regard, high fat diet (HFD) feeding in pregnancy has been shown to increase risks of metabolic diseases. Thus, we investigated the effects of supplementation of HFD with germinated brown rice (GBR) and GBR-derived gamma oryzanol-rich extract (OE) on insulin resistance and its epigenetic implications in pregnant rats and their offsprings. Pregnant female Sprague dawley rats were fed with HFD alone, HFD + GBR or HFD + OE (100 or 200 mg/kg/day) throughout pregnancy and lactation. Their offsprings were weaned at 4 weeks post-delivery and were followed up until 8 weeks. Serum levels of adipokines were measured in dams and their offsprings, and global DNA methylation and histone acetylation patterns were estimated from the liver. The dams and offsprings of the GBR and OE groups had lower weight gain, glycemic response, 8-Iso prostaglandin, retinol binding protein 4 and fasting insulin, and elevated adiponectin levels compared with the HFD group. Fasting leptin levels were lower only in the GBR groups. Hepatic global DNA methylation was lower in the GBR groups while hepatic H4 acetylation was lower in both GBR and OE dams. In the offsprings, DNA methylation and H4 acetylation were only lower in the OE group. However, dams and offsprings of the GBR and OE groups had higher hepatic H3 acetylation. GBR and OE can be used as functional ingredients for the amelioration of HFD-induced epigeneticallymediated insulin resistance.

  12. Compositional analyses of white, brown and germinated forms of popular Malaysian rice to offer insight into the growing diet-related diseases.

    Science.gov (United States)

    Abubakar, Bilyaminu; Yakasai, Hafeez Muhammad; Zawawi, Norhasnida; Ismail, Maznah

    2018-04-01

    Diet-related metabolic diseases, and especially obesity, are metabolic disorders with multifactorial aetiologies. Diet has been a cornerstone in both the aetiology and management of this metabolic disorders. Rice, a staple food for over half of the world's population, could be exploited as part of the solution to check this menace which has been skyrocketing in the last decade. The present study investigated nine forms of rice from three widely grown Malaysian rice cultivars for in vitro and in vivo (glycaemic index and load) properties that could translate clinically into a lower predisposition to diet-related diseases. The germinated brown forms of MRQ 74 and MR 84 rice cultivars had high amylose content percentages (25.7% and 25.0%), high relative percentage antioxidant scavenging abilities of 85.0% and 91.7%, relatively low glycaemic indices (67.6 and 64.3) and glycaemic load (32.3 and 30.1) values, and modest glucose uptake capabilities of 33.69% and 31.25%, respectively. The results show that all things being equal, rice cultivars that are germinated and high in amylose content when compared to their white and low amylose counterparts could translate into a lower predisposition to diet-related diseases from the dietary point of view in individuals who consume this cereal as a staple food. Copyright © 2017. Published by Elsevier B.V.

  13. Evolution of new rice varieties by induced mutations to increase yield and resistance to diseases and to improve seed quality

    International Nuclear Information System (INIS)

    Miah, A.J.; Bhatti, I.M.

    1968-01-01

    Seeds of two indica rice varieties namely, Kangni-27 (a coarse variety) and Dokri Basmati (a fine variety) were irradiated with 20, 25, 30, 35, 40, 45 and 50 kR of gamma rays from a 13,000-Ci 60 Co source. In the M 1 generation (1964), germination percentage, seedling height and seed fertility were studied. The data indicated that Kangni-27 is more radioresistant than Dokri Basmati. In the M 2 generation (1965) two polygenic traits, i.e. leaf size and grains per unit length were studied. From the analysis of the data it was found that variability was greater in the irradiated populations than in the non-irradiated controls. Apart from the study of the polygenic traits, several mutants which appeared to be useful to the breeder (e.g. dwarf, short-culm and early flowering) were isolated form the irradiated populations of Kangni-27. In the M 3 generation (1966) several agronomically important characters were studied in all the mutants isolated in the M 2 generation. It was noticed that the mean values of most of the characters of all the mutants deviated from the mean values of the respective controls. These deviations were both negative and positive. Further analysis is in progress. Three more experiments were started, two in the year 1965 on the effects of gamma rays and one in 1966 to compare the effects of EMS and gamma rays. (author). 31 refs, 3 figs, 6 tabs

  14. EFFECTS OF PARBOILING AND PHYSICO-CHEMICAL CHARACTERISTICS OF RICE ON THE GLYCEMIC AND INSULINEMIC INDICES IN TYPE 2 DIABETIC SUBJECT

    Directory of Open Access Journals (Sweden)

    Shahana Parvin

    2008-01-01

    Full Text Available Background and Purposes: To observe the influence of parboiling, amylose content and gelatinization temperature of rice on plasma glucose and insulin responses in type 2 diabetic subjects because diabetic subjects are especially prescribed usage of starchy foods with low glycemic responses. Methods: Seventeen type 2 diabetic subjects ingested five test meals of 50g available carbohydrate as white bread, cooked rice with high (29% and low amylose content (13%, undergoing different processing and gelatinization temperatures. The diets were taken in a random order after a 10h overnight fast with approximately 7 days interval as wash out period. Results: The glycemic index (GI of all rice varieties were lower than that of white bread (p<0.001. Furthermore, GI of parboiled rice with a high amylose content was lower than that of parboiled low amylose rice (50±7 vs 71±5, p <0.01. No differences were observed between parboiled rice with high and low gelatinization temperature (50±7 vs 47± 4, nor between non-parboiled and parboiled rice (52±7 vs 50±7. Insulin responses to the five test foods did not differ significantly in the study subjects. Conclusions: In type 2 diabetic subjects the investigated rices were all low glycemic as compared to white bread, independent of parboiling and physico-chemical characteristics. The study showed that the amylose content, but not the gelatinization temperature, may be an useful criteria in selection of low GI rices irrespective of parboiling status. Ibrahim Med. Coll. J. 2008; 2(1: 12-16

  15. Functional Study of Cytochrome P450 Enzymes from the Brown Planthopper (Nilaparvata lugens Stål) to Analyze Its Adaptation to BPH-Resistant Rice.

    Science.gov (United States)

    Peng, Lei; Zhao, Yan; Wang, Huiying; Song, Chengpan; Shangguan, Xinxin; Ma, Yinhua; Zhu, Lili; He, Guangcun

    2017-01-01

    Plant-insect interactions constitute a complex of system, whereby plants synthesize toxic compounds as the main defense strategy to combat herbivore assault, and insects deploy detoxification systems to cope with toxic plant compounds. Cytochrom P450s are among the main detoxification enzymes employed by insects to combat the chemical defenses of host plants. In this study, we used Nilaparvata lugens (BPH) to constitute an ideal system for studying plant-insect interactions. By feeding BPHs with artificial diets containing ethanol extracts, we show that biotype Y BPHs have a greater ability to metabolize exogenous substrates than biotype 1 BPHs. NlCPR knockdown inhibited the ability of BPHs to feed on YHY15. qRT-PCR was used to screen genes in the P450 family, and upregulation of CYP4C61, CYP6AX1 , and CYP6AY1 induced by YHY15 was investigated. When the three P450 genes were knocked down, only CYP4C61 dsRNA treatment was inhibited the ability of BPHs to feed on YHY15. These results indicate that BPH P450 enzymes are a key factor in the physiological functions of BPH when feeding on BPH-resistant rice.

  16. Functional Study of Cytochrome P450 Enzymes from the Brown Planthopper (Nilaparvata lugens Stål to Analyze Its Adaptation to BPH-Resistant Rice

    Directory of Open Access Journals (Sweden)

    Lei Peng

    2017-11-01

    Full Text Available Plant-insect interactions constitute a complex of system, whereby plants synthesize toxic compounds as the main defense strategy to combat herbivore assault, and insects deploy detoxification systems to cope with toxic plant compounds. Cytochrom P450s are among the main detoxification enzymes employed by insects to combat the chemical defenses of host plants. In this study, we used Nilaparvata lugens (BPH to constitute an ideal system for studying plant-insect interactions. By feeding BPHs with artificial diets containing ethanol extracts, we show that biotype Y BPHs have a greater ability to metabolize exogenous substrates than biotype 1 BPHs. NlCPR knockdown inhibited the ability of BPHs to feed on YHY15. qRT-PCR was used to screen genes in the P450 family, and upregulation of CYP4C61, CYP6AX1, and CYP6AY1 induced by YHY15 was investigated. When the three P450 genes were knocked down, only CYP4C61 dsRNA treatment was inhibited the ability of BPHs to feed on YHY15. These results indicate that BPH P450 enzymes are a key factor in the physiological functions of BPH when feeding on BPH-resistant rice.

  17. Silicon induces resistance to the brown spot fungus Cochliobolus miyabeanus by preventing the pathogen from hijacking the rice ethylene pathway

    Czech Academy of Sciences Publication Activity Database

    Van Bockhaven, J.; Spíchal, L.; Novák, Ondřej; Strnad, Miroslav; Asano, T.; Kikuchi, S.; Hofte, M.; De Vleesschauwer, D.

    2015-01-01

    Roč. 206, č. 2 (2015), s. 761-773 ISSN 0028-646X R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Bipolaris oryzae * Cochliobolus miyabeanus * disease resistance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.210, year: 2015

  18. Evaluation Some Properties of NanoMetakaolin or Rice Husk Ash Cement Mortar and its Resistance to Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Jassim Atiya Alwan

    2016-12-01

    Full Text Available The objective of this research is to find the optimum value of some properties like compressive, flexural strength of blended cement mortar by nanometakaolin ( NMK or rice husk ash (RHA and to evaluate the effect of high temperature on these properties. The ordinary Portland cement(OPC of mortar was partially substituted by NMK or RHA of 5,10,15 and 20% by weight of cement. (108 control and blended specimens were casted and tested at ambient temperature (33 ºC for compressive and flexural strength for 28 and 90 days. Another (270 of the control and blended specimens were casted and cured for 90 days and exposed to elevated temperature of a gradual increase in temperature up to 200 ºC,300 ºC, 400 ºC,600 ºC and 800 ºC for two hours in an electrical furnace and they were under the same previous tests. The test results at ambient temperature indicate that the optimum compressive and flexural strength was with ratio of 15% NMK cement replacement in mortar for 28 and 90 days but for RHA was ratio of 10% for 28 days and 15% of cement weight in mortar for 90 days compared to control specimens. The results of exposing control and blended specimens of (90 days to elevated temperature showed that the optimum strength for control and the best MK replacement ratio were found at 200 ºC, and the best RHA replacement ratio specimens was found at 300 ºC. It is also found that exposing the mortar to more than these temperatures destroyed its strength and it was detrimental to its properties.

  19. Overwintering physiology of the rice stem borer larvae, Chilo ...

    African Journals Online (AJOL)

    The rice stem borer, Chilo suppressalis (Walker), is a major rice pest around the world. A strong ability of the rice stem borer to adapt/resist cold temperature (cold hardiness) contributes to its survival through winter. However, the physiological mechanism of its cold hardiness is poorly understood. In this study, we ...

  20. Molecular dissection of the response of the rice Systemic Acquired Resistance Deficient 1 (SARD1) gene to different types of ionizing radiation.

    Science.gov (United States)

    Jung, In Jung; Hwang, Jung Eun; Han, Sung Min; Kim, Dong Sub; Ahn, Joon-Woo; Choi, Hong-Il; Kwon, Soon-Jae; Kang, Si-Yong; Kim, Jin-Baek

    2017-07-01

    Exposure to ionizing radiation induces plant defenses by regulating the expression of response genes. The systemic acquired resistance deficient 1 (SARD1) is a key gene in plant defense response. In this study, the function of Oryza sativa SARD1 (OsSARD1) was investigated after exposure of seeds/plants to ionizing radiation, jasmonic acid (JA) or salicylic acid (SA). Rice seeds exposed to two types of ionizing radiations (gamma ray [GR] and ion beam [IB]) were analyzed by quantitative reverse transcription PCR (qRT-PCR) to identify the genes that are altered in response to ionizing radiation. Then, OsSARD1-overexpressing homozygous Arabidopsis plants were generated to assess the effects of OsSARD1 in the response to irradiation. The phenotypes of these transgenic plants, as well as control plants, were monitored after GR irradiation at doses of 200 and 300 Gray (Gy). The OsSARD1 transcript was strongly downregulated after exposure to GR and IB irradiation. Previous phylogenetic analysis showed that the Arabidopsis SARD1 (AtSARD1) protein is closely related to Arabidopsis calmodulin-binding protein 60g (AtCBP60g), which is known to be required for activation of SA biosynthesis. In this study, phylogenetic analysis showed that OsSARD1 was grouped with AtSARD1. The OsSARD1 gene was induced after exposure to SA and JA. The biological phenotype of OsSARD1-overexpressing Arabidopsis plants was examined. OsSARD1-overexpressing plants displayed resistance to GR; in comparison with wild-type plants, the height and weight of OsSARD1-overexpressing plants were significantly greater after GR irradiation. In addition, OsSARD1 protein was abundantly accumulated in the nucleus. The results indicate that OsSARD1 plays an important role in the regulation of the defense responses to GR and IB irradiation and exhibits phytohormone induced expression.

  1. Characterization of the β-Carotene Hydroxylase Gene DSM2 Conferring Drought and Oxidative Stress Resistance by Increasing Xanthophylls and Abscisic Acid Synthesis in Rice1[C][W][OA

    Science.gov (United States)

    Du, Hao; Wang, Nili; Cui, Fei; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2010-01-01

    Drought is a major limiting factor for crop production. To identify critical genes for drought resistance in rice (Oryza sativa), we screened T-DNA mutants and identified a drought-hypersensitive mutant, dsm2. The mutant phenotype was caused by a T-DNA insertion in a gene encoding a putative β-carotene hydroxylase (BCH). BCH is predicted for the biosynthesis of zeaxanthin, a carotenoid precursor of abscisic acid (ABA). The amounts of zeaxanthin and ABA were significantly reduced in two allelic dsm2 mutants after drought stress compared with the wild type. Under drought stress conditions, the mutant leaves lost water faster than the wild type and the photosynthesis rate, biomass, and grain yield were significantly reduced, whereas malondialdehyde level and stomata aperture were increased in the mutant. The mutant is also hypersensitive to oxidative stresses. The mutant had significantly lower maximal efficiency of photosystem II photochemistry and nonphotochemical quenching capacity than the wild type, indicating photoinhibition in photosystem II and decreased capacity for eliminating excess energy by thermal dissipation. Overexpression of DSM2 in rice resulted in significantly increased resistance to drought and oxidative stresses and increases of the xanthophylls and nonphotochemical quenching. Some stress-related ABA-responsive genes were up-regulated in the overexpression line. DSM2 is a chloroplast protein, and the response of DSM2 to environmental stimuli is distinctive from the other two BCH members in rice. We conclude that the DSM2 gene significantly contributes to control of the xanthophyll cycle and ABA synthesis, both of which play critical roles in the establishment of drought resistance in rice. PMID:20852032

  2. Effects of Population Density and Host Availability on The Migration Process of Brown Planthopper Fed Using Susceptible and Resistant Rice Varieties

    Directory of Open Access Journals (Sweden)

    Imam Habibi

    2016-12-01

    Full Text Available Brown planthopper, Nilaparvata lugens Stal. (Hemiptera: Delphacidae, is an important pest of rice. This pest can cause hopperburn and field failure. This research aimed to determine the effects of population density and host availability on migration of N. lugens. The criteria used to justify the effects of host availability and population density on migration of N. lugens were based the hardness and tannin tests of the rice stems, fecundity of N. lugens, and the life cycle of N. lugens. The research was conducted under the temperature of 29.42°C with relative humidity of 61% and Light 12: Dark 12 times, using ten pairs of N. lugens brachypterous (F0 constant and then was added with five male adults on fifth days after the first infestation (F0 changed. The varieties used were IR64, as a resistant variety, and Ketan Lusi, as a susceptible variety. The results showed that the adding of the macropterous males did not affect the number of macropterous, because of that has been preplanned by the F0. Therefore, the percentage of existing macropterous was 51−52%.   INTISARI   Wereng Batang Cokelat (WBC merupakan salah satu hama tanaman padi yang sangat penting. Kerusakan parah dapat menyebabkan hopperburn dan puso (gagal panen. Tujuan penelitian ini adalah mengetahui pengaruh kepadatan populasi dan tanaman inang sebagai tempat migrasi WBC. Parameter yang dikaji untuk mengetahui pengaruh kepadatan populasi WBC dan tanaman inang tempat migrasi WBC berdasarkan tingkat kekerasan dan kandungan tanin batang tanaman padi, fekunditas WBC, dan siklus hidup WBC. Penelitian ini dilakukan pada temperatur 29.42˚C dengan kelembapan relatif 61% dan durasi siang hari 12 jam: durasi malam hari 12 jam. Metode yang dilakukan adalah dengan menggunakan 10 pasang imago WBC brakhiptera (F0 konstan, kemudian dilakukan penambahan 5 ekor imago jantan pada hari kelima setelah infestasi awal (F0 diubah. Varietas padi yang digunakan yaitu padi varietas IR64 sebagai varietas

  3. Estabilidade de géis de amido de milho normal, ceroso e com alto teor de amilose adicionados de gomas guar e xantana durante os processos de congelamento e descongelamento Freeze-thaw stability of normal, waxy and high amylose corn starch gels with added guar and xanthan gums

    Directory of Open Access Journals (Sweden)

    Fernanda Hart Weber

    2008-06-01

    Full Text Available O objetivo do presente trabalho foi estudar os efeitos das gomas guar e xantana sobre a estabilidade dos géis de amido de milho normal, ceroso e com alto teor de amilose submetidos aos processos de congelamento e descongelamento. Os géis desses amidos, com concentração total de sólidos de 10% e adicionados das gomas (0,15; 0,50; 0,85 e 1%, foram submetidos a 5 ciclos de congelamento (20 horas a -18 °C e descongelamento (4 horas a 25 °C, com exceção dos géis com alto teor de amilose, que foram submetidos a apenas 1 ciclo, devido à perda da estrutura de gel. A determinação da sinérese (porcentagem de água liberada foi realizada pela diferença entre a massa inicial e a massa final das amostras. O gel de amido de milho normal liberou 74,45% de água, sendo que a adição de 1% da goma xantana reduziu significativamente a sinérese para 66,43%. A adição de 0,85 e 1% da goma xantana também reduziu a sinérese dos géis de amido ceroso. O menor teor de sinérese foi obtido com a utilização de 1% de goma xantana ao gel de amido de milho com alto teor de amilose, evidenciando a ação crioprotetora desta goma.The objective of the present work was to study the effects of guar and xanthan gums on the stability of normal, waxy and high amylose corn starch gels, submitted to freeze-thaw processes. The gels of these starches with a total solids content of 10% and added gums (0.15;0.50;0.85and1%, were submitted to 5 freezing (20 hours, -18 °C and thawing (4 hours, 25 °C cycles, with exception of the high amylose gels that were submitted to only 1 cycle. Syneresis (% water released was determined by the difference between the initial and final masses of the samples. The normal corn starch gel released 74.45% water and the addition of 1% xanthan gum significantly reduced syneresis to 66.43%. The incorporation of 0.85 and 1% xanthan gum also reduced syneresis of waxy starch gels. The lowest level of syneresis was reached with the use of 1

  4. Caracterização físico-química, reológica, morfológica e térmica dos amidos de milho normal, ceroso e com alto teor de amilose Physicochemical, rheological, morphological, and thermal characterization of normal, waxy, and high amylose corn starches

    Directory of Open Access Journals (Sweden)

    Fernanda Hart Weber

    2009-12-01

    Full Text Available O objetivo do presente estudo foi avaliar os amidos de milho normal, ceroso e com alto teor de amilose, fabricados pela National Starch, por meio da determinação das suas características físico-químicas, morfológicas, térmicas e reológicas. O amido de milho com alto teor de amilose (AM apresentou teor de amilose igual a 71%, sendo que os valores obtidos para o amido de milho normal (M e o amido de milho ceroso (AP foram de 27,8 e 1,8%, respectivamente. Traços de proteína e lipídios foram encontrados nas amostras. O amido de milho ceroso apresentou maior viscosidade máxima e uma menor tendência à retrogradação, se comparado ao amido de milho normal. O amido AP apresentou menor entalpia de gelatinização, como pode ser observado nas análises de calorimetria exploratória diferencial (DSC, na qual a temperatura de gelatinização foi de 75 °C e o ΔH de 3,34 J.g-1, e também na análise de RVA (Rapid Visco Analyser, em que a temperatura de pasta foi de 71 °C. Apresentando, dessa forma, valores inferiores aos verificados para os outros amidos. O valor do ΔH de retrogradação do amido AP, mostrou-se 25,8% inferior ao ΔH do amido M. O amido AM apresentou o valor de 26,38 J.g-1, demonstrando o maior envolvimento da molécula de amilose no processo de retrogradação. Isso também foi evidenciado pela medida da força dos géis: o gel de AM apresentou força 99,18% superior, retrogradando mais que os outros amidos. As análises de difração de raio X mostraram que os amidos de milho normal e ceroso apresentaram um padrão de difração do tipo A e o amido de milho com alto teor de amilose apresentou padrão do tipo B.The objective of this work was to evaluate normal, waxy, and high amylose corn starches from National Starch, through the determination of the physicochemical, morphological, thermal, and rheological properties. The high amylose corn starch (AM presented amylose content of 71%, and the value of this component for the

  5. Differences in the arbuscular mycorrhizal fungi-improved rice resistance to low temperature at two N levels: aspects of N and C metabolism on the plant side.

    Science.gov (United States)

    Liu, Zhi-Lei; Li, Yuan-Jing; Hou, Hong-Yan; Zhu, Xian-Can; Rai, Vandna; He, Xing-Yuan; Tian, Chun-Jie

    2013-10-01

    We performed an experiment to determine how N and C metabolism is involved in the low-temperature tolerance of mycorrhizal rice (Oryza sativa) at different N levels and examined the possible signaling molecules involved in the stress response of mycorrhizal rice. Pot cultures were performed, and mycorrhizal rice growth was evaluated based on treatments at two temperatures (15 °C and 25 °C) and two N levels (20 mg pot(-1) and 50 mg pot(-1)). The arbuscular mycorrhizal fungi (AMF) colonization of rice resulted in different responses of the plants to low and high N levels. The mycorrhizal rice with the low N supplementation had more positive feedback from the symbiotic AMF, as indicated by accelerated N and C metabolism of rice possibly involving jasmonic acid (JA) and the up-regulation of enzyme activities for N and C metabolism. Furthermore, the response of the mycorrhizal rice plants to low temperature was associated with P uptake and nitric oxide (NO). Crown Copyright © 2013. Published by Elsevier Masson SAS. All rights reserved.

  6. Intra lines uniformity and inter lines variation of rice mutants resulting from irradiation of South Kalimantan local varieties

    International Nuclear Information System (INIS)

    Raihani Wahdah; Gusti Rumayadi; Rahmi Zulhidiani

    2016-01-01

    The preference of farmer in tidal swamp on local rice varieties are quite high, but local varieties have a long life and low yield characters, so it needs to be improved for the trait. This study is part of activities of the local rice varieties improvement to generate promising lines were short-moderate aged, but the slimming and pera (high amylose content) grains maintained. The aims of this study were to determine the intra lines uniformity and the inter lines variation of M5 generation of rice mutant lines. The experiment was carried out in the Experimental Station of Agriculture Faculty, Lambung Mangkurat University from March to September 2014. The experiment used 150 earliest flowering lines of 300 M5 mutant lines that were planted. Intra lines uniformity were analysed by comparing the variance of each mutant lines with variance of its parent, while the variation among lines were analyzed by comparing the variance of all lines with variance of its parent. More than 85 % M5 mutant lines from Siam Harli as parent and > 79 % of Siam Kuatek as parent are uniform. The uniform character at all M5 mutant lines, both of Siam Harli or Siam Kuatek parent are the harvest age, the filled grains number, and the empty grains number. There is no variability between M5 mutant lines, but some of M5 mutant lines from Siam Harli and Siam Kuatek have some better characters than their parents, so there is an opportunity for selection. (author)

  7. Long branch-chains of amylopectin with B-type crystallinity in rice seed with inhibition of starch branching enzyme I and IIb resist in situ degradation and inhibit plant growth during seedling development : Degradation of rice starch with inhibition of SBEI/IIb during seedling development.

    Science.gov (United States)

    Pan, Ting; Lin, Lingshang; Wang, Juan; Liu, Qiaoquan; Wei, Cunxu

    2018-01-08

    Endosperm starch provides prime energy for cereal seedling growth. Cereal endosperm with repression of starch branching enzyme (SBE) has been widely studied for its high resistant starch content and health benefit. However, in barley and maize, the repression of SBE changes starch component and amylopectin structure which affects grain germination and seedling establishment. A high resistant starch rice line (TRS) has been developed through inhibiting SBEI/IIb, and its starch has very high resistance to in vitro hydrolysis and digestion. However, it is unclear whether the starch resists in situ degradation in seed and influences seedling growth after grain germination. In this study, TRS and its wild-type rice cultivar Te-qing (TQ) were used to investigate the seedling growth, starch property changes, and in situ starch degradation during seedling growth. The slow degradation of starch in TRS seed restrained the seedling growth. The starch components including amylose and amylopectin were simultaneously degraded in TQ seeds during seedling growth, but in TRS seeds, the amylose was degraded faster than amylopectin and the amylopectin long branch-chains with B-type crystallinity had high resistance to in situ degradation. TQ starch was gradually degraded from the proximal to distal region of embryo and from the outer to inner in endosperm. However, TRS endosperm contained polygonal, aggregate, elongated and hollow starch from inner to outer. The polygonal starch similar to TQ starch was completely degraded, and the other starches with long branch-chains of amylopectin and B-type crystallinity were degraded faster at the early stage of seedling growth but had high resistance to in situ degradation during TRS seedling growth. The B-type crystallinity and long branch-chains of amylopectin in TRS seed had high resistance to in situ degradation, which inhibited TRS seedling growth.

  8. Not any type of rice performs equally to improve lactose-induced diarrhea characteristics in rats: is amylose an antidiarrheal factor?

    Directory of Open Access Journals (Sweden)

    Ana Lia Felipoff

    Full Text Available The effectiveness of different types of rice in relation to their ability to accelerate diarrhea recovering was evaluated in a rat model of osmotic diarrhea (OD. Animals (90-100 g received protein free diet until reaching up to 20% weight loss, followed by lactose rich diet (LRD to induce osmotic diarrhea. Rats presenting osmotic diarrhea were divided into 4 groups, which received lactose rich diet for 4 days from 8 am to 8 pm, and one of three experimental products containing 6% rice flour differing in amylose content during the night: high (HA, intermediate (IA, and low (LA. A group fed stock diet containing equivalent amount of lactose was taken as control and allowed to recover spontaneously. Amylose and viscosity (cp at 25 °C, 10 rpm of final products were determined. Effectiveness was expressed as the ratio between percentages of normal vs. diarrheic stools during the treatment. Fecal characteristics in this rat model improved only as result of feeding high amylose content (HA type of rice. In this experimental model of osmotic diarrhea in young rats, the antidiarrheal effects of rice were strongly dependent on the type of diet used and appear to be related to its amylose content.

  9. Changes in DNA Methylation Pattern at Two Seedling Stages in Water Saving and Drought-Resistant Rice Variety after Drought Stress Domestication

    Directory of Open Access Journals (Sweden)

    Xiao-guo ZHENG

    2014-09-01

    Full Text Available Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tillering to grain-filling stages in six successive growth cycles. The variations in DNA methylation pattern between the original generation (G0 and the sixth generation (G6 were analyzed by using methylation sensitive amplification polymorphism method. The results revealed that the methylated loci accounted for 34.3% to 34.8% of the total loci. Among these methylated loci, 83.1% to 84.8% were full- and hyper-methylated and 15.2% to 16.9% were hemi-methylated. The DNA methylation level decreased from the three-leaf to four-leaf stages in Huhan 3. Differentially methylated loci (DML between generations or/and between different developmental stages accounted for 4.0% of the total loci, most of which were only related to plant development (57.9%. Compared to G0, the DNA methylation pattern of G6 changed after drought domestication, at the three-leaf stage, de-methylation accounting for 59.1%, while at the four-leaf stage, re-methylation for 47.9%. Genome-wide alternations of DNA methylation were observed between the two seedling stages, and DML mainly occurred on the gene's promoter and exon region. The genes related to DML involved in a wide range of functional biology and participated in many important biological processes.

  10. OsCESA9 conserved-site mutation leads to largely enhanced plant lodging resistance and biomass enzymatic saccharification by reducing cellulose DP and crystallinity in rice.

    Science.gov (United States)

    Li, Fengcheng; Xie, Guosheng; Huang, Jiangfeng; Zhang, Ran; Li, Yu; Zhang, Miaomiao; Wang, Yanting; Li, Ao; Li, Xukai; Xia, Tao; Qu, Chengcheng; Hu, Fan; Ragauskas, Arthur J; Peng, Liangcai

    2017-09-01

    Genetic modification of plant cell walls has been posed to reduce lignocellulose recalcitrance for enhancing biomass saccharification. Since cellulose synthase (CESA) gene was first identified, several dozen CESA mutants have been reported, but almost all mutants exhibit the defective phenotypes in plant growth and development. In this study, the rice (Oryza sativa) Osfc16 mutant with substitutions (W481C, P482S) at P-CR conserved site in CESA9 shows a slightly affected plant growth and higher biomass yield by 25%-41% compared with wild type (Nipponbare, a japonica variety). Chemical and ultrastructural analyses indicate that Osfc16 has a significantly reduced cellulose crystallinity (CrI) and thinner secondary cell walls compared with wild type. CESA co-IP detection, together with implementations of a proteasome inhibitor (MG132) and two distinct cellulose inhibitors (Calcofluor, CGA), shows that CESA9 mutation could affect integrity of CESA4/7/9 complexes, which may lead to rapid CESA proteasome degradation for low-DP cellulose biosynthesis. These may reduce cellulose CrI, which improves plant lodging resistance, a major and integrated agronomic trait on plant growth and grain production, and enhances biomass enzymatic saccharification by up to 2.3-fold and ethanol productivity by 34%-42%. This study has for the first time reported a direct modification for the low-DP cellulose production that has broad applications in biomass industries. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Creation of transgenic rice plants producing small interfering RNA of Rice tungro spherical virus.

    Science.gov (United States)

    Le, Dung Tien; Chu, Ha Duc; Sasaya, Takahide

    2015-01-01

    Rice tungro spherical virus (RTSV), also known as Rice waika virus, does not cause visible symptoms in infected rice plants. However, the virus plays a critical role in spreading Rice tungro bacilliform virus (RTBV), which is the major cause of severe symptoms of rice tungro disease. Recent studies showed that RNA interference (RNAi) can be used to develop virus-resistance transgenic rice plants. In this report, we presented simple procedures and protocols needed for the creation of transgenic rice plants capable of producing small interfering RNA specific against RTSV sequences. Notably, our study showed that 60 out of 64 individual hygromycin-resistant lines (putative transgenic lines) obtained through transformation carried transgenes designed for producing hairpin double-stranded RNA. Northern blot analyses revealed the presence of small interfering RNA of 21- to 24-mer in 46 out of 56 confirmed transgenic lines. Taken together, our study indicated that transgenic rice plants carrying an inverted repeat of 500-bp fragments encoding various proteins of RTSV can produce small interfering RNA from the hairpin RNA transcribed from that transgene. In light of recent studies with other viruses, it is possible that some of these transgenic rice lines might be resistant to RTSV.

  12. (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... tics, led us to predict that pollen cell abortion in this type of rice when ... averages of natural day-light-lengths and temperatures were used. A natural long ... blocks were allowed to grow under natural growth conditions (which.

  13. Indica rice (Oryza sativa, BR29 and IR64).

    Science.gov (United States)

    Datta, Karabi; Datta, Swapan Kumar

    2006-01-01

    Rice is the world's most important food crop. Indica-type rice provides the staple food for more than half of the world population. To satisfy the growing demand of the ever-increasing population, more sustained production of indica-type rice is needed. In addition, because of the high per capita consumption of indica rice, improvement of any traits including its nutritive value may have a significant positive health outcome for the rice-consuming population. Rice yield productivity is greatly affected by different biotic stresses, like diseases and insect pests, and abiotic stresses like drought, cold, and salinity. Attempts to improve resistance in rice to these stresses by conventional breeding through introgression of traits have limited success owing to a lack of resistance germplasm in the wild relatives. Gene transfer technology with genes from other sources can be used to make rice plants resistant or tolerant to insect pests, diseases, and different environmental stresses. For improving the nutritional value of the edible endosperm part of the rice, genes for increasing iron, beta-carotene, or better quality protein can be introduced in rice plants by genetic engineering. Different crops have been transformed using various gene transfer methods, such as protoplast transformation, biolistic, and Agrobacterium-mediated transformation. This chapter describes the Agrobacterium-mediated transformation protocol for indica-type rice. The selectable marker genes used are hygromycin phosphotransferase (hpt), neomycin phosphotransferase (nptII), or phosphomannose isomerase (pmi), and, accordingly, the selection agents are hygromycin, kanamycin (G418), or mannose, respectively.

  14. Immunotoxicological Evaluation of Genetically Modified Rice Expressing Cry1Ab/Ac Protein (TT51-1) by a 6-Month Feeding Study on Cynomolgus Monkeys

    OpenAIRE

    Tan, Xiaoyan; Zhou, Xiaobing; Tang, Yao; Lv, Jianjun; Zhang, Lin; Sun, Li; Yang, Yanwei; Miao, Yufa; Jiang, Hua; Chen, Gaofeng; Huang, Zhiying; Wang, Xue

    2016-01-01

    The present study was performed to evaluate the food safety of TT51-1, a new type of genetically modified rice that expresses the Cry1Ab/Ac protein (Bt toxin) and is highly resistant to most lepidopteran pests. Sixteen male and 16 female cynomolgus monkeys were randomly divided into four groups: conventional rice (non-genetically modified rice, non-GM rice), positive control, 17.5% genetically modified rice (GM rice) and 70% GM rice. Monkeys in the non-GM rice, positive control, and GM rice g...

  15. The rice terpene synthase gene OsTPS19 functions as an (S)-limonene synthase in planta, and its overexpression leads to enhanced resistance to the blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Chen, Xujun; Chen, Hao; Yuan, Joshua S; Köllner, Tobias G; Chen, Yuying; Guo, Yufen; Zhuang, Xiaofeng; Chen, Xinlu; Zhang, Yong-Jun; Fu, Jianyu; Nebenführ, Andreas; Guo, Zejian; Chen, Feng

    2018-03-06

    Rice blast disease, caused by the fungus Magnaporthe oryzae, is the most devastating disease of rice. In our ongoing characterization of the defence mechanisms of rice plants against M. oryzae, a terpene synthase gene OsTPS19 was identified as a candidate defence gene. Here, we report the functional characterization of OsTPS19, which is up-regulated by M. oryzae infection. Overexpression of OsTPS19 in rice plants enhanced resistance against M. oryzae, while OsTPS19 RNAi lines were more susceptible to the pathogen. Metabolic analysis revealed that the production of a monoterpene (S)-limonene was increased and decreased in OsTPS19 overexpression and RNAi lines, respectively, suggesting that OsTPS19 functions as a limonene synthase in planta. This notion was further supported by in vitro enzyme assays with recombinant OsTPS19, in which OsTPS19 had both sesquiterpene activity and monoterpene synthase activity, with limonene as a major product. Furthermore, in a subcellular localization experiment, OsTPS19 was localized in plastids. OsTPS19 has a highly homologous paralog, OsTPS20, which likely resulted from a recent gene duplication event. We found that the variation in OsTPS19 and OsTPS20 enzyme activities was determined by a single amino acid in the active site cavity. The expression of OsTPS20 was not affected by M. oryzae infection. This indicates functional divergence of OsTPS19 and OsTPS20. Lastly, (S)-limonene inhibited the germination of M. oryzae spores in vitro. OsTPS19 was determined to function as an (S)-limonene synthase in rice and plays a role in defence against M. oryzae, at least partly, by inhibiting spore germination. © 2018 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  16. ROOT ANATOMICAL PLASTICITY IN RESPONSE TO SALT STRESS UNDER REAL AND FULL-SEASON FIELD CONDITIONS AND DETERMINATION OF NEW ANATOMIC SELECTION CHARACTERS FOR BREEDING SALT-RESISTANT RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Mehmet AYBEKE

    2016-12-01

    Full Text Available Specific understanding of root anatomy plasticity under salt stress is lacking and requires creation of efficient screening techniques for stress condition s. To fill this gap, this study aimed to determine the anatomical plasticity in root chracteristics of 31 different rice cultivars (from ‘Best’ to ‘Low’ yielding grown under real field conditions (saline and non-saline from planting to harvesting and to reveal detailed root anatomical parameters that can be used to select and breed salt-tolerant rice. Anatomical and histochemical features of all cultivars and thin structures of the apoplastic barriers were investigated. The amount of silica (Si, 35 different anatomical characteristics, anatomical plasticity characteristics, plasticity rates, plasticity trends and changes and strategies of each group under saline and non-saline conditions were compared. The results showed that protective anatomical characters improved/remained equal to, and worsened/remained equal to those of the controls, in the ‘Best’ and other groups, respectively, from non-saline to saline conditions. Anatomical plasticity is essentially directly related to apoplastic barrier features. High genotypic variation was observed in root anatomy in all cultivars, but foremost traits were as follows: (1 cell size, (2 Si presence, (3 Si accumulation shape, (4 Si distribution towards root stele, (5 xylem arch features, (6 lignification-suberization properties in apoplastic barriers and their degrees, (7 presence/absence of idioblast cells filled with gummic and phenolic substances and (8 moderate anatomical plasticity. Cultivars with the most stabile anatomy under saline and non-saline conditions should be used to select and breed salt-resistant rice.

  17. Perinatal exposure to germinated brown rice and its gamma amino-butyric acid-rich extract prevents high fat diet-induced insulin resistance in first generation rat offspring

    Directory of Open Access Journals (Sweden)

    Hadiza Altine Adamu

    2016-02-01

    Full Text Available Background: Evidence suggests perinatal environments influence the risk of developing insulin resistance. Objective: The present study was aimed at determining the effects of intrauterine exposure to germinated brown rice (GBR and GBR-derived gamma (γ aminobutyric acid (GABA extract on epigenetically mediated high fat diet–induced insulin resistance. Design: Pregnant Sprague Dawley rats were fed high-fat diet (HFD, HFD+GBR, or HFD+GABA throughout pregnancy until 4 weeks postdelivery. The pups were weighed weekly and maintained on normal pellet until 8 weeks postdelivery. After sacrifice, biochemical markers of obesity and insulin resistance including oral glucose tolerance test, adiponectin, leptin, and retinol binding protein-4 (RBP4 were measured. Hepatic gene expression changes and the global methylation and histone acetylation levels were also evaluated. Results: Detailed analyses revealed that mothers given GBR and GABA extract, and their offspring had increased adiponectin levels and reduced insulin, homeostasis model assessment of insulin resistance, leptin, oxidative stress, and RBP4 levels, while their hepatic mRNA levels of GLUT2 and IPF1 were increased. Furthermore, GBR and GABA extract lowered global DNA methylation levels and modulated H3 and H4 acetylation levels. Conclusions: These results showed that intrauterine exposure to GBR-influenced metabolic outcomes in offspring of rats with underlying epigenetic changes and transcriptional implications that led to improved glucose homeostasis.

  18. Expressing OsMPK4 Impairs Plant Growth but Enhances the Resistance of Rice to the Striped Stem Borer Chilo suppressalis

    OpenAIRE

    Xiaoli Liu; Jiancai Li; Liping Xu; Qi Wang; Yonggen Lou

    2018-01-01

    Mitogen-activated protein kinases (MPKs) play a central role not only in plant growth and development, but also in plant responses to abiotic and biotic stresses, including pathogens. Yet, their role in herbivore-induced plant defenses and their underlying mechanisms remain largely unknown. Here, we cloned a rice MPK gene, OsMPK4, whose expression was induced by mechanical wounding, infestation of the striped stem borer (SSB) Chilo suppressalis, and treatment with jasmonic acid (JA), but not ...

  19. Effect of transgenic Bacillus thuringiensis rice lines on mortality and feeding behavior of rice stem borers (Lepidoptera: Crambidae).

    Science.gov (United States)

    Chen, Hao; Zhang, Guoan; Zhang, Qifa; Lin, Yongjun

    2008-02-01

    Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future.

  20. Comparative physical mapping of rice BAC clones linked to resistance genes Glh,Bph-3 and xa-5 in Oryza sativa L.and O.granulata Nees et Am.ex Watt.

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhiyong; TAN Guangxuan; YOU Aiqing; HE Guangyuan; SHE Chaowen; LI Lijia; SONG Yunchun

    2004-01-01

    Oryza granulata Nees et Arn. ex Watt. is one of the three wild relatives of rice, which are the most valuable for study and utilization in China. In this study, the homology and physical locations of three rice resistance genes, Glh,Bph-3 and xa-5 are comparatively analyzed between O. sativa and O. granulata by Southern blotting and fluorescence in situ hybridization (FISH). The results of Southern blotting indicate that there exist homologous sequences of the tested RFLP markers in O. granulata. By using three bacterial artificial chromosome (BAC) clones scanned by the tested RFLP as probes, FISH signals are detected on both mitotic and pachytene chromosomes in O. sativa and O. granulata.Dual-color FISH demonstrates that two of the three BAC clones (14E16 and 38J9) are located on the short arm of the same chromosome pair in O. granulata. Additionally, colinearity is shown for the two clones between O. sativa and O.granulata. Another BAC clone 44B4 is located on the end of the short arm of other chromosome pair in these two species.Although the phylogenetic relationship between O. sativa and O. granulata is the most distinct in Oryza and these two species have evidently different biological features and ecological habits, the relative lengths and arm ratios of the detected chromosomes and the relative positions of the tested clone signals on chromosomes in O. granulata are quite similar to those in O. sativa.

  1. Induced Mutations in Thai Rice

    International Nuclear Information System (INIS)

    Klakhaeng, Kanchana

    2014-01-01

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

  2. Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

  3. MULTI-COUNTRY ASSESSMENT OF BARRIERS TO ACCEPTANCE OF GM RICE

    OpenAIRE

    Durand-Morat, Alvaro; Wailes, Eric; Alam, MJ; Mwaijande, Francis; Tsiboe, Francis

    2015-01-01

    Genetically modified (GM) rice has been developed to confer pest resistance, herbicide tolerance and health benefits, yet regulatory, policy and market barriers prevent commercialization of GM rice. This study assesses factors based on consumer survey results that assess acceptance of GM rice in 5 selected countries, namely, Bangladesh, Colombia, Ghana, Honduras, and Tanzania.

  4. A Novel Reference Plasmid for the Qualitative Detection of Genetically Modified Rice in Food and Feed

    OpenAIRE

    Li, Liang; Dong, Mei; An, Na; Liang, Lixia; Wan, Yusong; Jin, Wujun

    2015-01-01

    Rice is one of the most important food crops in the world. Genetically modified (GM) technology has been used in rice to confer herbicide tolerance and pathogen or insect resistance. China invests heavily in research on GM rice. By the end of 2014, at least 250 transgenic rice lines had been developed in China. To monitor the presence of GM rice in food and feed, we collected information on foreign elements from 250 transgenic rice lines and found 5 elements, including the Agrobacterium tumef...

  5. Efficacy and economics of different herbicides in aerobic rice system ...

    African Journals Online (AJOL)

    Aerobic rice system, the most promising irrigation water saving rice production technology, is highly impeded by severe weed pressure. Weed control through the use of same herbicide causes development of herbicide resistant weed biotypes and serious problem in weed management. This study was aimed at finding out ...

  6. Deficiencies in both starch synthase IIIa and branching enzyme IIb lead to a significant increase in amylose in SSIIa-inactive japonica rice seeds.

    Science.gov (United States)

    Asai, Hiroki; Abe, Natsuko; Matsushima, Ryo; Crofts, Naoko; Oitome, Naoko F; Nakamura, Yasunori; Fujita, Naoko

    2014-10-01

    Starch synthase (SS) IIIa has the second highest activity of the total soluble SS activity in developing rice endosperm. Branching enzyme (BE) IIb is the major BE isozyme, and is strongly expressed in developing rice endosperm. A mutant (ss3a/be2b) was generated from wild-type japonica rice which lacks SSIIa activity. The seed weight of ss3a/be2b was 74-94% of that of the wild type, whereas the be2b seed weight was 59-73% of that of the wild type. There were significantly fewer amylopectin short chains [degree of polymerization (DP) ≤13] in ss3a/be2b compared with the wild type. In contrast, the amount of long chains (DP ≥25) connecting clusters of amylopectin in ss3a/be2b was higher than in the wild type and lower than in be2b. The apparent amylose content of ss3a/be2b was 45%, which was >1.5 times greater than that of either ss3a or be2b. Both SSIIIa and BEIIb deficiencies led to higher activity of ADP-glucose pyrophosphorylase (AGPase) and granule-bound starch synthase I (GBSSI), which partly explains the high amylose content in the ss3a/be2b endosperm. The percentage apparent amylose content of ss3a and ss3a/be2b at 10 days after flowering (DAF) was higher than that of the wild type and be2b. At 20 DAF, amylopectin biosynthesis in be2b and ss3a/be2b was not observed, whereas amylose biosynthesis in these lines was accelerated at 30 DAF. These data suggest that the high amylose content in the ss3a/be2b mutant results from higher amylose biosynthesis at two stages, up to 20 DAF and from 30 DAF to maturity. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. Purification, molecular cloning and heterologous expression of a glutathione S-transferase involved in insecticide resistance from the rice brown planthopper, Nilaparvata lugens.

    OpenAIRE

    Vontas, John G; Small, Graham J; Nikou, Dimitra C; Ranson, Hilary; Hemingway, Janet

    2002-01-01

    A novel glutathione S-transferase (GST)-based pyrethroid resistance mechanism was recently identified in Nilaparvata lugens [Vontas, Small and Hemingway (2001) Biochem. J. 357, 65-72]. To determine the nature of GSTs involved in conferring this resistance, the GSTs from resistant and susceptible strains of N. lugens were partially purified by anion exchange and affinity chromatography. The majority of peroxidase activity, previously correlated with resistance, was confined to the fraction tha...

  8. Comparative transcriptome analysis of two rice varieties in response to rice stripe virus and small brown planthoppers during early interaction.

    Directory of Open Access Journals (Sweden)

    Wenjing Zheng

    Full Text Available Rice stripe, a virus disease, transmitted by a small brown planthopper (SBPH, has greatly reduced production of japonica rice in East Asia, especially in China. Although we have made great progress in mapping resistance genes, little is known about the mechanism of resistance. By de novo transcriptome assembling, we gained sufficient transcript data to analyze changes in gene expression of early interaction in response to SBPH and RSV infection in rice. Respectively 648 and 937 DEGs were detected from the disease-resistant (Liaonong 979 and the susceptible (Fengjin varieties, most of which were up-regulated. We found 37 genes related to insect resistance, which mainly included genes for jasmonate-induced protein, TIFY protein, lipoxygenase, as well as trypsin inhibitor genes and transcription factor genes. In the interaction process between RSV and rice, 87 genes were thought to be related to RSV resistance; these primarily included 12 peroxidase biosynthesis genes, 12 LRR receptor-like protein kinase genes, 6 genes coding pathogenesis-related proteins, 4 glycine-rich cell wall structural protein genes, 2 xyloglucan hydrolase genes and a cellulose synthase. The results indicate that the rice-pathogen interaction happened both in disease-resistant and susceptible varieties, and some genes related to JA biosynthesis played key roles in the interaction between SBPHs and rice. When rice was infected by RSV a hypersensitive reaction (HR in the disease-resistant variety was suppressed, which resulted from an increase in peroxidase expression and down-regulation of LRR receptor-like protein kinase and pathogenesis-related proteins, while, the changes of peroxidase biosynthesis, glycine-rich cell wall structural protein, cellulose synthase and xyloglucan endotransglucosylase/hydrolase could lead to the strengthening of physical barriers of rice, which may be an important resistance mechanism to RSV in rice.

  9. Comparative transcriptome analysis of two rice varieties in response to rice stripe virus and small brown planthoppers during early interaction.

    Science.gov (United States)

    Zheng, Wenjing; Ma, Li; Zhao, Jiaming; Li, Zhiqiang; Sun, Fuyu; Lu, Xiaochun

    2013-01-01

    Rice stripe, a virus disease, transmitted by a small brown planthopper (SBPH), has greatly reduced production of japonica rice in East Asia, especially in China. Although we have made great progress in mapping resistance genes, little is known about the mechanism of resistance. By de novo transcriptome assembling, we gained sufficient transcript data to analyze changes in gene expression of early interaction in response to SBPH and RSV infection in rice. Respectively 648 and 937 DEGs were detected from the disease-resistant (Liaonong 979) and the susceptible (Fengjin) varieties, most of which were up-regulated. We found 37 genes related to insect resistance, which mainly included genes for jasmonate-induced protein, TIFY protein, lipoxygenase, as well as trypsin inhibitor genes and transcription factor genes. In the interaction process between RSV and rice, 87 genes were thought to be related to RSV resistance; these primarily included 12 peroxidase biosynthesis genes, 12 LRR receptor-like protein kinase genes, 6 genes coding pathogenesis-related proteins, 4 glycine-rich cell wall structural protein genes, 2 xyloglucan hydrolase genes and a cellulose synthase. The results indicate that the rice-pathogen interaction happened both in disease-resistant and susceptible varieties, and some genes related to JA biosynthesis played key roles in the interaction between SBPHs and rice. When rice was infected by RSV a hypersensitive reaction (HR) in the disease-resistant variety was suppressed, which resulted from an increase in peroxidase expression and down-regulation of LRR receptor-like protein kinase and pathogenesis-related proteins, while, the changes of peroxidase biosynthesis, glycine-rich cell wall structural protein, cellulose synthase and xyloglucan endotransglucosylase/hydrolase could lead to the strengthening of physical barriers of rice, which may be an important resistance mechanism to RSV in rice.

  10. Habilidade competitiva de plantas de arroz com biótipos de capim-arroz resistente ou suscetível ao quinclorac Competitive ability of rice plants with barnyardgrass biotypes resistant or susceptible to quinclorac

    Directory of Open Access Journals (Sweden)

    S.P. Tironi

    2009-06-01

    Full Text Available Objetivou-se com este trabalho avaliar a habilidade competitiva de plantas de arroz cultivar BRS Pelota com biótipos de capim-arroz resistente ou suscetível ao herbicida quinclorac. Para isso, foi instalado experimento em casa de vegetação, em delineamento completamente casualizado com quatro repetições, sendo os tratamentos dispostos em esquema fatorial 2 x 6. As unidades experimentais constaram de vasos plásticos contendo 10 dm³ de solo, cujo pH e nível de nutrientes foram previamente corrigidos. Os tratamentos consistiram na competição entre uma planta de arroz, cultivar BRS Pelota, com populações (0, 1, 2, 3, 4 ou 5 plantas por vaso dos biótipos de capim-arroz resistente (ECH-13 ou suscetível (ECH-12 ao herbicida quinclorac. As avaliações foram realizadas aos 40 dias após emergência, sendo avaliados; massa seca da parte aérea (MSPA, taxa de crescimento (TC, área foliar específica (AFE, razão de massa foliar (RMF, razão de área foliar (RAF e índice de área foliar (IAF. A interferência no desenvolvimento do cultivar de arroz BRS Pelota foi proporcionalmente maior com o aumento da população de ambos os biótipos de capim-arroz. Os biótipos apresentaram, em geral, habilidade competitiva similar.The objective of this study was to evaluate the competitive ability of the rice cultivar BRS Pelota with biotypes resistant or susceptible to the herbicide Quinclorac. The experiment was conducted under greenhouse conditions in a completely randomized design with four replications, with the treatments arranged in a 2 x 6 factorial. The experimental units consisted of plastic pots containing 10 dm³ of soil, with pH and nutrient level being previously corrected. The treatments consisted of a competition between a rice plant, BRS Pelota cultivar, with populations (0, 1, 2, 3, 4 or 5 plants per pot of the barnyardgrass biotypes resistant (ECH-13 or susceptible (ECH -12 to the herbicide Quinclorac. The evaluations were performed

  11. Economic and Environmental Impacts of Adoption of Genetically Modified Rice in California

    OpenAIRE

    Bond, Craig A.; Carter, Colin A.; Farzin, Y. Hossein

    2005-01-01

    Rice production in California is intensive in input usage. Weed resistance has led to growing chemical usage and has raised costs for many rice producers in California. In recent years, widespread adoption of genetically modified (GM) soybeans, corn, canola, and cotton has provided growers of those crops with new production alternatives that reduce chemical usage. But GM rice has not yet been approved for commercial production in California or elsewhere. One reason that GM rice production has...

  12. Purification, molecular cloning and heterologous expression of a glutathione S-transferase involved in insecticide resistance from the rice brown planthopper, Nilaparvata lugens.

    Science.gov (United States)

    Vontas, John G; Small, Graham J; Nikou, Dimitra C; Ranson, Hilary; Hemingway, Janet

    2002-03-01

    A novel glutathione S-transferase (GST)-based pyrethroid resistance mechanism was recently identified in Nilaparvata lugens [Vontas, Small and Hemingway (2001) Biochem. J. 357, 65-72]. To determine the nature of GSTs involved in conferring this resistance, the GSTs from resistant and susceptible strains of N. lugens were partially purified by anion exchange and affinity chromatography. The majority of peroxidase activity, previously correlated with resistance, was confined to the fraction that bound to the affinity column, which was considerably elevated in the resistant insects. A cDNA clone encoding a GST (nlgst1-1) - the first reported GST sequence from Hemiptera with up to 54% deduced amino-acid identity with other insect class I GSTs - was isolated from a pyrethroid-resistant strain. Northern analysis showed that nlgst1-1 was overexpressed in resistant insects. nlgst1-1 was expressed in Escherichia coli, purified and characterized. The ability of the recombinant protein to bind to the S-hexylglutathione affinity matrix, its substrate specificities and its immunological properties confirmed that this GST was one from the elevated subset of N. lugens GSTs. Peroxidase activity of the recombinant nlgst1-1 indicated that it had a role in resistance, through detoxification of lipid peroxidation products induced by pyrethroids. Southern analysis of genomic DNA from the resistant and susceptible strains indicated that GST-based insecticide resistance may be associated with gene amplification in N. lugens.

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

    Directory of Open Access Journals (Sweden)

    LONG Si-si

    2016-09-01

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

  14. Current Insights into Research on Rice stripe virus

    Directory of Open Access Journals (Sweden)

    Won Kyong Cho

    2013-09-01

    Full Text Available Rice stripe virus (RSV is one of the most destructive viruses of rice, and greatly reduces rice production in China, Japan, and Korea, where mostly japonica cultivars of rice are grown. RSV is transmitted by the small brown plant-hopper (SBPH in a persistent and circulative-propagative manner. Several methods have been developed for detection of RSV, which is composed of four single-stranded RNAs that encode seven proteins. Genome sequence data and comparative phylogenetic analysis have been used to identify the origin and diversity of RSV isolates. Several rice varieties resistant to RSV have been selected and QTL analysis and fine mapping have been intensively performed to map RSV resistance loci or genes. RSV genes have been used to generate several genetically modified transgenic rice plants with RSV resistance. Recently, genome-wide transcriptome analyses and deep sequencing have been used to identify mRNAs and small RNAs involved in RSV infection; several rice host factors that interact with RSV proteins have also been identified. In this article, we review the current statues of RSV research and propose integrated approaches for the study of interactions among RSV, rice, and the SBPH.

  15. Rice peasants and rice research in Colombia

    NARCIS (Netherlands)

    Spijkers, P.A.N.M.

    1983-01-01

    Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp

  16. Rice breeding with induced mutations in France

    Energy Technology Data Exchange (ETDEWEB)

    Marie, R [Station d' Amelioration des Plantes, Institut National de Recherches Agronomiques, Montpellier (France)

    1970-03-01

    Mutation experiments with rice at Montpellier yielded strains with improved lodging resistance, grain size, maturing time, milling quality and other characters. The general performance of these mutant strains was tested in field trials. Further mutagenic treatments were made to improve the high-yielding short grain varieties with regard to grain quality and seed dormancy. (author)

  17. In vitro gastric digestion of cooked white and brown rice using a dynamic rat stomach model.

    Science.gov (United States)

    Wu, Peng; Deng, Renpan; Wu, Xuee; Wang, Yong; Dong, Zhizhong; Dhital, Sushil; Chen, Xiao Dong

    2017-12-15

    The changes in physical, rheological and enzyme-digestive behaviours of cooked white and brown rice, with similar amylose content, were investigated using a dynamic in vitro rat stomach (DIVRS) model and a static soaking method. The brown rice had a higher resistance on disintegration and lower gastric emptying rate with 53% of the brown rice particles retained in the stomach at the end compared to 32% for the white rice. Furthermore, the release rate of maltose from the starch hydrolysis was higher in the white rice throughout the digestion suggesting the lower glycemic potency of the brown rice. These differences could be contributed from the rigid bran layer in the brown rice which would inhibit the moisture absorption into rice kernels, limit textural degradation, and generate higher gastric digesta viscosity leading to lower mixing and mass transfer efficiency. This study suggests that the structural difference could affect physiochemical properties during gastric digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Studies on the application of gamma rays and chemical substances to rice growing

    Energy Technology Data Exchange (ETDEWEB)

    Gi, Ha Byong

    1985-01-10

    It was suggested that highly salt-resistant strains can be primarily selected among plenty of strains by constrasting the coefficient of biological salt-resistance in the early developing stage of the rice plant, and high-yielding strains can be firmly selected among these salt-resistant strains in the early developing stage, by transplanting these strains into the rice-field and by contrasting the coefficient of biological salt-resistance of them. It was confirmed that the salt-resistant character of the rice strains are differently manifested according to each developmental stage.

  19. Water management, rice varieties and mycorrhizal inoculation influence arsenic concentration and speciation in rice grains.

    Science.gov (United States)

    Zhang, Xin; Wu, Songlin; Ren, Baihui; Chen, Baodong

    2016-05-01

    A pot experiment was carried out to investigate the effects of water management and mycorrhizal inoculation on arsenic (As) uptake by two rice varieties, the As-resistant BRRI dhan 47 (B47) and As-sensitive BRRI dhan 29 (B29). Grain As concentration of B47 plants was significantly lower than that of B29, and grain As concentration of B47 was higher under flooding conditions than that under aerobic conditions. In general, mycorrhizal inoculation (Rhizophagus irregularis) had no significant effect on grain As concentrations, but decreased the proportion of inorganic arsenic (iAs) in grains of B47. The proportion of dimethylarsinic acid (DMA) in the total grain As was dramatically higher under flooding conditions. Results demonstrate that rice variety selection and appropriate water management along with mycorrhizal inoculation could be practical countermeasures to As accumulation and toxicity in rice grains, thus reducing health risks of As exposure in rice diets.

  20. Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae) Alleviation in the United States.

    Science.gov (United States)

    Nalley, Lawton; Tsiboe, Francis; Durand-Morat, Alvaro; Shew, Aaron; Thoma, Greg

    2016-01-01

    Rice blast (Magnaporthe oryzae) is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA) show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion) impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in production.

  1. Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae Alleviation in the United States.

    Directory of Open Access Journals (Sweden)

    Lawton Nalley

    Full Text Available Rice blast (Magnaporthe oryzae is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in

  2. Thermoplastic starch materials prepared from rice starch

    International Nuclear Information System (INIS)

    Pontes, Barbara R.B.; Curvelo, Antonio A.S.

    2009-01-01

    Rice starch is a source still little studied for the preparation of thermoplastic materials. However, its characteristics, such as the presence of proteins, fats and fibers may turn into thermoplastics with a better performance. The present study intends the evaluation of the viability of making starch thermoplastic from rice starch and glycerol as plasticizer. The results of X-ray diffraction and scanning electronic microscopy demonstrate the thermoplastic acquisition. The increase of plasticizer content brings on more hydrophilic thermoplastics with less resistance to tension and elongation at break. (author)

  3. Burkholderia glumae: next major pathogen of rice?

    Science.gov (United States)

    Ham, Jong Hyun; Melanson, Rebecca A; Rush, Milton C

    2011-05-01

    Burkholderia glumae causes bacterial panicle blight of rice, which is an increasingly important disease problem in global rice production. Toxoflavin and lipase are known to be major virulence factors of this pathogen, and their production is dependent on the TofI/TofR quorum-sensing system, which is mediated by N-octanoyl homoserine lactone. Flagellar biogenesis and a type III secretion system are also required for full virulence of B. glumae. Bacterial panicle blight is thought to be caused by seed-borne B. glumae; however, its disease cycle is not fully understood. In spite of its economic importance, neither effective control measures for bacterial panicle blight nor rice varieties showing complete resistance to the disease are currently available. A better understanding of the molecular mechanisms underlying B. glumae virulence and of the rice defence mechanisms against the pathogen would lead to the development of better methods of disease control for bacterial panicle blight. Bacteria; Proteobacteria; Betaproteobacteria; Burkholderiales; Burkholderiaceae; Burkholderia. Gram-negative, capsulated, motile, lophotrichous flagella, pectolytic. Aborted seed, empty grains as a result of failure of grain filling, brown spots on panicles, seedling rot. Seed sterilization, planting partially resistant lines (no completely resistant line is available). KNOWN VIRULENCE FACTORS: Toxoflavin, lipase, type III effectors. © 2010 LSU AGCENTER. MOLECULAR PLANT PATHOLOGY © 2010 BSPP AND BLACKWELL PUBLISHING LTD.

  4. Study of the Effects of Monacolin K and Other Constituents of Red Yeast Rice on Obesity, Insulin-Resistance, Hyperlipidemia, and Nonalcoholic Steatohepatitis Using a Mouse Model of Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Makoto Fujimoto

    2012-01-01

    Full Text Available Purpose. Nonalcoholic fatty liver disease (NAFLD is a progressive and intractable disease associated with metabolic syndrome. Red yeast rice (RYR contains monacolin K, a potent inhibitor of HMG-CoA reductase, and its consumption decreases cholesterol and triglyceride levels. We examined the efficacy of RYR constituents using a novel metabolic syndrome-NAFLD mouse model (MSG mice. Methods. Two types of RYR grown under different culture conditions were used. 1P-DU contained only 0.002 g/100 g of monacolin K, whereas 3P-D1 contained 0.131 g/100 g. MSG mice were divided into three groups: control (C group fed standard food, RYR-C group fed standard food with 1% 1P-DU, and RYR-M group fed standard food with 1% 3P-D1. Mice were examined from 12 to 24 weeks of age. Results. Serum insulin, leptin, and liver damage as well as macrophage aggregation in visceral fat in RYR-C and RYR-M groups were lower than those in C group. The serum adiponectin levels in RYR-C group were significantly higher than those in RYR-M and C groups. Conclusions. RYR was effective against obesity-related inflammation, insulin resistance, and NAFLD in MSG mice irrespective of monacolin K levels. GABA and various peptides produced during fermentation were determined as the active constituents of RYR.

  5. Effects of partially replacing dietary soybean meal or cottonseed meal with completely hydrolyzed feather meal (defatted rice bran as the carrier) on production, cytokines, adhesive gut bacteria, and disease resistance in hybrid tilapia (Oreochromis niloticus ♀ × Oreochromis aureus ♂).

    Science.gov (United States)

    Zhang, Zhen; Xu, Li; Liu, Wenshu; Yang, Yalin; Du, Zhenyu; Zhou, Zhigang

    2014-12-01

    We formulated experimental diets for hybrid tilapia to investigate the effects of replacing dietary soybean meal (SBM) or cottonseed meal (CSM) by completely hydrolyzed feather meal (defatted rice bran as the carrier; abbreviated as CHFM), with emphasis on fish growth, the composition of adhesive gut bacteria, intestinal and hepatic immune responses, and disease resistance. A series of four isonitrogenous (33% crude protein) and isolipidic (6% crude lipid) diets were formulated to replace the isonitrogenous percentages of CSM or SBM by 6% or 12% CHFM. Quadruplicate groups of healthy and uniformly sized hybrid tilapia were assigned to each experimental diet. Fish were hand fed three times a day for 8 weeks at a rearing temperature of 25-28 °C. The growth performance of hybrid tilapia fed diets with partial replacement of dietary SBM or CSM with CHFM was comparable to the group of fish fed the control diet. The CHFM-containing diets affected the intestinal autochthonous bacterial community in similar ways. All CHFM-containing diets stimulated the expression of heat shock protein 70 in the intestine but suppressed its expression in the liver. Only the CHFM6/SBM diet stimulated the expression of interleukin-1β in intestine, and no effects were observed in all diets to the expression of interleukin-1β in liver. Thus, regarding the immune response in the intestine and liver, CHFM is a good alternative protein source that induces less stress in the host. CHFM did not affect disease resistance to Aeromonas hydrophila infection in hybrid tilapia. These data suggest that CHFM is a good alternative to partially replace SBM and CSM in tilapia feed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Immunotoxicological Evaluation of Genetically Modified Rice Expressing Cry1Ab/Ac Protein (TT51-1) by a 6-Month Feeding Study on Cynomolgus Monkeys

    Science.gov (United States)

    Tan, Xiaoyan; Zhou, Xiaobing; Tang, Yao; Lv, Jianjun; Zhang, Lin; Sun, Li; Yang, Yanwei; Miao, Yufa; Jiang, Hua; Chen, Gaofeng; Huang, Zhiying; Wang, Xue

    2016-01-01

    The present study was performed to evaluate the food safety of TT51-1, a new type of genetically modified rice that expresses the Cry1Ab/Ac protein (Bt toxin) and is highly resistant to most lepidopteran pests. Sixteen male and 16 female cynomolgus monkeys were randomly divided into four groups: conventional rice (non-genetically modified rice, non-GM rice), positive control, 17.5% genetically modified rice (GM rice) and 70% GM rice. Monkeys in the non-GM rice, positive control, and GM rice groups were fed on diets containing 70% non-GM rice, 17.5% GM rice or 70% GM rice, respectively, for 182 days, whereas animals in the positive group were intravenously injected with cyclophosphamide every other day for a total of four injections before the last treatment. Six months of treatment did not yield abnormal observations. Specifically, the following parameters did not significantly differ between the non-GM rice group and GM rice groups: body weight, food consumption, electrocardiogram, hematology, immuno-phenotyping of lymphocytes in the peripheral blood, mitogen-induced peripheral blood lymphocyte proliferation, splenocyte proliferation, KLH-T cell-dependent antibody response, organ weights and ratios, and histological appearance (p>0.05). Animals from the GM rice group differed from animals in the non-GM rice group (pGM rice. In conclusion, a 6-month feeding study of TT51-1 did not show adverse immunotoxicological effects on cynomolgus monkeys. PMID:27684490

  7. Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes

    Directory of Open Access Journals (Sweden)

    Siré Christelle

    2008-03-01

    Full Text Available Abstract Background The effects of viral infection involve concomitant plant gene variations and cellular changes. A simple system is required to assess the complexity of host responses to viral infection. The genome of the Rice yellow mottle virus (RYMV is a single-stranded RNA with a simple organisation. It is the most well-known monocotyledon virus model. Several studies on its biology, structure and phylogeography have provided a suitable background for further genetic studies. 12 rice chromosome sequences are now available and provide strong support for genomic studies, particularly physical mapping and gene identification. Results The present data, obtained through the cDNA-AFLP technique, demonstrate differential responses to RYMV of two different rice cultivars, i.e. susceptible IR64 (Oryza sativa indica, and partially resistant Azucena (O. s. japonica. This RNA profiling provides a new original dataset that will enable us to gain greater insight into the RYMV/rice interaction and the specificity of the host response. Using the SIM4 subroutine, we took the intron/exon structure of the gene into account and mapped 281 RYMV stress responsive (RSR transcripts on 12 rice chromosomes corresponding to 234 RSR genes. We also mapped previously identified deregulated proteins and genes involved in partial resistance and thus constructed the first global physical map of the RYMV/rice interaction. RSR transcripts on rice chromosomes 4 and 10 were found to be not randomly distributed. Seven genes were identified in the susceptible and partially resistant cultivars, and transcripts were colocalized for these seven genes in both cultivars. During virus infection, many concomitant plant gene expression changes may be associated with host changes caused by the infection process, general stress or defence responses. We noted that some genes (e.g. ABC transporters were regulated throughout the kinetics of infection and differentiated susceptible and

  8. Genetic Analysis and Preliminary Mapping of Two Recessive Resistance Genes to Brown Planthopper, Nilaparvata lugens Stål in Rice

    Directory of Open Access Journals (Sweden)

    Li-yuan HOU

    2011-09-01

    Full Text Available An F2 population derived from the cross of WB01, an introgression line resistant to brown planthopper (BPH originated from Oryza rufipogon Griff. and a susceptible indica variety 9311, was developed for genetic analysis and gene mapping. The population with 303 F2:3 families was genotyped by 141 simple sequence repeat (SSR markers and used for gene mapping. Two softwares, Mapmaker/Exp 3.0 and Windows QTL Cartographer V2.0 were applied to detect QTLs. Totally, two QTLs resistant to BPH, named temporarily as bph22(t and bph23(t, were identified to locate on chromosomes 4 and 8, individually had LOD values of 2.92 and 3.15, and explained 11.3% and 14 .9% of the phenotypic variation, respectively.

  9. Phloem-exudate proteome analysis of response to insect brown plant-hopper in rice.

    Science.gov (United States)

    Du, Ba; Wei, Zhe; Wang, Zhanqi; Wang, Xiaoxiao; Peng, Xinxin; Du, Bo; Chen, Rongzhi; Zhu, Lili; He, Guangcun

    2015-07-01

    Brown plant-hopper (Nilaparvata lugens Stål, BPH), one of the most devastating agricultural insect pests of rice throughout Asia, ingests nutrients from rice sieve tubes and causes a dramatic yield loss. Planting resistant variety is an efficient and economical way to control this pest. Understanding the mechanisms of host resistance is extremely valuable for molecular design of resistant rice variety. Here, we used an iTRAQ-based quantitative proteomics approach to perform analysis of protein expression profiles in the phloem exudates of BPH-resistant and susceptible rice plants following BPH infestation. A total of 238 proteins were identified, most of which were previously described to be present in the phloem of rice and other plants. The expression of genes for selected proteins was confirmed using a laser capture micro-dissection method and RT-PCR. The mRNAs for three proteins, RGAP, TCTP, and TRXH, were further analyzed by using in situ mRNA hybridization and localized in the phloem cells. Our results showed that BPH feeding induced significant changes in the abundance of proteins in phloem sap of rice involved in multiple pathways, including defense signal transduction, redox regulation, and carbohydrate and protein metabolism, as well as cell structural proteins. The results presented provide new insights into rice resistance mechanisms and should facilitate the breeding of novel elite BPH-resistant rice varieties. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Rice (Oryza) hemoglobins

    Science.gov (United States)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  11. Using the concept of pseudo amino acid composition to predict resistance gene against Xanthomonas oryzae pv. oryzae in rice: an approach from chaos games representation.

    Science.gov (United States)

    Jingbo, Xia; Silan, Zhang; Feng, Shi; Huijuan, Xiong; Xuehai, Hu; Xiaohui, Niu; Zhi, Li

    2011-09-07

    To evaluate the possibility of an unknown protein to be a resistant gene against Xanthomonas oryzae pv. oryzae, a different mode of pseudo amino acid composition (PseAAC) is proposed to formulate the protein samples by integrating the amino acid composition, as well as the Chaos games representation (CGR) method. Some numerical comparisons of triangle, quadrangle and 12-vertex polygon CGR are carried to evaluate the efficiency of using these fractal figures in classifiers. The numerical results show that among the three polygon methods, triangle method owns a good fractal visualization and performs the best in the classifier construction. By using triangle + 12-vertex polygon CGR as the mathematical feature, the classifier achieves 98.13% in Jackknife test and MCC achieves 0.8462. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Adaptive Epigenetic Differentiation between Upland and Lowland Rice Ecotypes Revealed by Methylation-Sensitive Amplified Polymorphism

    OpenAIRE

    Xia, Hui; Huang, Weixia; Xiong, Jie; Tao, Tao; Zheng, Xiaoguo; Wei, Haibin; Yue, Yunxia; Chen, Liang; Luo, Lijun

    2016-01-01

    The stress-induced epimutations could be inherited over generations and play important roles in plant adaption to stressful environments. Upland rice has been domesticated in water-limited environments for thousands of years and accumulated drought-induced epimutations of DNA methylation, making it epigenetically differentiated from lowland rice. To study the epigenetic differentiation between upland and lowland rice ecotypes on their drought-resistances, the epigenetic variation was investig...

  13. Semi-dwarf mutants for rice improvement

    International Nuclear Information System (INIS)

    Othman, Ramli; Osman, Mohammad; Ibrahim, Rusli

    1990-01-01

    Full text: MARDI and the National University of Malaysia embarked on a programme to induce resistance against blast in rice in 1978. MARDI also obtained semi dwarf mutants of cvs 'Mahsuri', 'Muda', 'Pongsu seribu' and 'Jarum Mas', which are under evaluation. The popular local rice variety 'Manik' was subjected to gamma irradiation (15-40 krad) and 101 promising semidwarf mutants have been obtained following selection in M 2 -M 6 . 29 of them show grain yields of 6.0-7.3 t/ha, compared with 5.7t for 'Manik'. Other valuable mutants were found showing long grain, less shattering, earlier maturity, and glutinous endosperm. One mutant, resistant to brown plant hopper yields 6.3t/ha. (author)

  14. Effects of cooking methods and starch structures on starch hydrolysis rates of rice.

    Science.gov (United States)

    Reed, Michael O; Ai, Yongfeng; Leutcher, Josh L; Jane, Jay-lin

    2013-07-01

    This study aimed to understand effects of different cooking methods, including steamed, pilaf, and traditional stir-fried, on starch hydrolysis rates of rice. Rice grains of 3 varieties, japonica, indica, and waxy, were used for the study. Rice starch was isolated from the grain and characterized. Amylose contents of starches from japonica, indica, and waxy rice were 13.5%, 18.0%, and 0.9%, respectively. The onset gelatinization temperature of indica starch (71.6 °C) was higher than that of the japonica and waxy starch (56.0 and 56.8 °C, respectively). The difference was attributed to longer amylopectin branch chains of the indica starch. Starch hydrolysis rates and resistant starch (RS) contents of the rice varieties differed after they were cooked using different methods. Stir-fried rice displayed the least starch hydrolysis rate followed by pilaf rice and steamed rice for each rice variety. RS contents of freshly steamed japonica, indica, and waxy rice were 0.7%, 6.6%, and 1.3%, respectively; those of rice pilaf were 12.1%, 13.2%, and 3.4%, respectively; and the stir-fried rice displayed the largest RS contents of 15.8%, 16.6%, and 12.1%, respectively. Mechanisms of the large RS contents of the stir-fried rice were studied. With the least starch hydrolysis rate and the largest RS content, stir-fried rice would be a desirable way of preparing rice for food to reduce postprandial blood glucose and insulin responses and to improve colon health of humans. © 2013 Institute of Food Technologists®

  15. Performance of different rice cultivars and insecticides against tryporyza incertulas (walker) and cnaphalocrocis medinalis (guenee)

    International Nuclear Information System (INIS)

    Rashid, M.M.U.; Khattak, M.K.; Momin, A.; Amir, M.; Latif, A.

    2013-01-01

    Studies were conducted to determine the toxicity of Roll Up (7.2% G), Furadan (3G), Solomon (300-0-Teq), Belt (48% SC), Karuz (4% GR) and Shark Super (6% G) and relative resistance of rice varieties IRRI-6, KSK-282, DR-83, Basmati-370, Basmati-385 and Super Basmati against rice stem borer and rice leaf folder and their effect on yield ha/sup -1/. Roll Up and Shark Super ranked first in their efficacy against rice stem borer; as 0.64% and 0.63% dead hearts and 0.32 and 0.33% white heads were recorded, respectively, and which were significantly (P < 0.05) lower than control. Solomon with 0.73% infestation was the most effective insecticide against rice leaf folder. Rice varieties IRRI-6 and KSK-282 were the most resistant varieties against rice stem borer; as 14.73% and 18.34% dead hearts, and 4.33% and 4.77% white heads were significantly (P < 0.05) lower than the other tested varieties. Similarly IRRI-6, KSK-282 and DR-83 also showed resistance to rice leaf folder. Basmati-385 was the most susceptible variety against rice leaf folder. KSK-282 with 5656 kg ha/sup -1/ yield ranked first. Plots treated with shark super resulted in to highest (7014 kg ha/sup -1/) yield whereas; plots treated with Karuz resulted into lowest (5984 kg ha/sup -1/) yield. (author)

  16. Effects of Sorghum [Sorghum bicolor (L. Moench] Crude Extracts on Starch Digestibility, Estimated Glycemic Index (EGI, and Resistant Starch (RS Contents of Porridges

    Directory of Open Access Journals (Sweden)

    Dilek Lemlioglu-Austin

    2012-09-01

    Full Text Available Bran extracts (70% aqueous acetone of specialty sorghum varieties (tannin, black, and black with tannin were used to investigate the effects of sorghum phenolic compounds on starch digestibility, Estimated Glycemic Index (EGI, and Resistant Starch (RS of porridges made with normal corn starch, enzyme resistant high amylose corn starch, and ground whole sorghum flours. Porridges were cooked with bran extracts in a Rapid Visco-analyser (RVA. The cooking trials indicated that bran extracts of phenolic-rich sorghum varieties significantly reduced EGI, and increased RS contents of porridges. Thus, there could be potential health benefits associated with the incorporation of phenolic-rich sorghum bran extracts into foods to slow starch digestion and increase RS content.

  17. Transcriptional changes of rice in response to rice black-streaked dwarf virus.

    Science.gov (United States)

    Ahmed, Mohamed M S; Ji, Wen; Wang, Muyue; Bian, Shiquan; Xu, Meng; Wang, Weiyun; Zhang, Jiangxiang; Xu, Zhihao; Yu, Meimei; Liu, Qiaoquan; Zhang, Changquan; Zhang, Honggen; Tang, Shuzhu; Gu, Minghong; Yu, Hengxiu

    2017-09-10

    Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Although a great deal of effort has been made to elucidate the interactions among the virus, insect vectors, host and environmental conditions, few RBSDV proteins involved in pathogenesis have been identified, and the biological basis of disease development in rice remains largely unknown. Transcriptomic information associated with the disease development in rice would be helpful to unravel the biological mechanism. To determine how the rice transcriptome changes in response to RBSDV infection, we carried out RNA-Seq to perform a genome-wide gene expression analysis of a susceptible rice cultivar KTWYJ3. The transcriptomes of RBSDV-infected samples were compared to those of RBSDV-free (healthy) at two time points (time points are represented by group I and II). The results derived from the differential expression analysis in RBSDV-infected libraries vs. healthy ones in group I revealed that 102 out of a total of 281 significant differentially expressed genes (DEGs) were up-regulated and 179 DEGs were down-regulated. Of the 2592 identified DEGs in group II, 1588 DEGs were up-regulated and 1004 DEGs were down-regulated. A total of 66 DEGs were commonly identified in both groups. Of these 66 DEGs, expression patterns for 36 DEGs were similar in both groups. Our analysis demonstrated that some genes related to disease defense and stress resistance were up-regulated while genes associated with chloroplast were down-regulated in response to RBSDV infection. In addition, some genes associated with plant-height were differentially expressed. This result indicates those genes might be involved in dwarf symptoms caused by RBSDV. Taken together, our results provide a genome-wide transcriptome analysis for rice plants in response to RBSDV infection which may contribute to the

  18. Marker-assisted improvement of the elite restorer line of rice, RPHR ...

    Indian Academy of Sciences (India)

    V. ABHILASH KUMAR

    Introduction. Rice plays an important role in feeding the world's popula- ... requirement of the increasing population. This can be ... the gene has shown promising levels of durable resistance ... of fertility-linked alleles with respect to the major fertility restorer ..... in India. In Hybrid rice for food security, poverty alleviation and.

  19. Molecular screening of rice ( Oryza sativa L.) germplasm for Xa4 ...

    African Journals Online (AJOL)

    DNA fingerprinting results indicated the presence of Xa4 gene in 41 entries, while 14 lines were positive for xa5 gene. Only one local line was carrying Xa21 gene along with Xa4. Thus, the present study will not only be helpful for rice breeders to develop new rice varieties carrying disease resistant genes, but will also ...

  20. Climate variability impacts on rice crop production in pakistan

    International Nuclear Information System (INIS)

    Shakoor, U.; Saboor, A.; Baig, I.

    2015-01-01

    The climate variability has affected the agriculture production all over the globe. This concern has motivated important changes in the field of research during the last decade. Climate changes are believed to have declining effects towards crop production in Pakistan. This study carries an empirical investigation of the effects of climate change on rice crop of Pakistan by employing Vector Auto Regression (VAR) model. Annual seasonal data of the climatic variables from 1980 to 2013 has been used. Results confirmed that rising mean maximum temperature would lead to reduction in rice production while increase in mean minimum temperature would be advantageous towards rice production. Variation in mean minimum temperature brought about seven percent increase in rice productivity as shown by Variance Decomposition. Mean precipitation and mean temperature would increase rice production but simulations scenarios for 2030 confirmed that much increase in rainfall and mean temperature in long run will negatively affect rice production in future. It is therefore important to follow adequate policy action to safeguard crop productions from disastrous effects. Development of varieties resistant to high temperatures as well as droughts will definitely enhance resilience of rice crop in Pakistan. (author)

  1. Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice

    International Nuclear Information System (INIS)

    Sumiya, Misako; Uchida, Shigeo; Muramatsu, Yasuyuki; Ohmomo, Yoichiro; Yamaguchi, Shuho; Obata, Hitoshi.

    1987-01-01

    Experiments were carried out in order to obtain information required for establishing transfer coefficients of gaseous iodine (I 2 ) to rough rice, brown rice and polished rice. The gaseous iodine deposited on young rice plants before the heading period was scarcely found in the rough rice harvested at the full ripe stage. The biological half life of iodine in hull, however, was much slower than that in leaves of 14 days. The translocation of iodine from leaves and stalks to rough rice was not clearly recognized. Therefore, it was deduced that iodine found in brown rice mainly should originate from that deposited on the hull. The distribution ratios of iodine between rough rice and brown rice, and between brown rice and polished rice were 100:4 and 100:30 on 100 grains basis, respectively. If average normalized deposition velocity (V d(m) ) or derived deposition velocity (V s ) are given, the transfer coefficients of gaseous iodine to rough rice (TF r ), brown rice (TF b ) and polished rice (TF p ) could be calculated. (author)

  2. Genomics of interaction between the brown planthopper and rice.

    Science.gov (United States)

    Jing, Shengli; Zhao, Yan; Du, Bo; Chen, Rongzhi; Zhu, Lili; He, Guangcun

    2017-02-01

    Rice (Oryza sativa L.) and the brown planthopper (Nilaparvata lugens (Stål)) form a model system for dissection of the mechanism of interaction between insect pest and crop. In this review, we focus on the genomics of BPH-rice interaction. On the side of rice, a number of BPH-resistance genes have been identified genetically. Thirteen of these genes have been cloned which shed a light on the molecular basis of the interaction. On the aspect of BPH, a lot of salivary proteins have been identified using transcriptome and proteome techniques. The genetic loci of virulence were mapped in BPH genome based on the linkage map. The understanding of interaction between BPH and rice will provide novel insights into efficient control of this pest. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. The role of biotechnology to ensure rice food security

    International Nuclear Information System (INIS)

    Teng, P.S.

    2002-01-01

    Rice as a food is key to the survival of more than 60% of the world population, most of whom live in Asia. Food security in Asia is therefore strongly dependent on an adequate, available supply of affordable rice. Experts estimate that global rice supply would need to increase at an average of 1.7% per annum for the next 20 years, and average rice yields must roughly double in the next 20 years in both the irrigated and favourable rainfed lowland environments, if a global shortage is to be avoided. At the same time that the need to increase total production, and unit area productivity is being felt, society is also demanding that agricultural practices be environment friendly and be part of a sustainable agricultural system. Rice breeders have seen increased difficulties to source and utilize new genetic resources for genetic improvement of yield potential from within the rice genome. As with other cereals, rice yield potential has not been dramatically increased in the last decade when compared to the quantum increase of the early Green Revolution years. Furthermore, pest-induced losses currently account for up to 30% of the loss in yield potential. Biotechnology, especially recombinant DNA technology, offers tools to transfer genes from outside the rice genome to address the critical issues of raising the yield potential, increasing tolerance or resistance to insects, diseases and a biotic stresses, to increase the efficiency of pest management, and also to improve the nutritive value of the rice grain. Genetically modified crops have a demonstrated record of environmental and food safety, and all such crops undergo a process of safety assessment and regulatory approval before they are put into the marketplace. Serious social issues, however, arise in matching the capacity of biotechnology to change crops, and in what changes society is willing to accept; and at this early stage of biotechnology applications, science-based approaches are important so that emotion

  4. Prevalence of Rice Yellow Mottle Virus (RYMV) on Rice Plants ...

    African Journals Online (AJOL)

    Abstract. Incidence of Rice yellow mottle virus (RYMV) on rice plants (ofada) grown in two local government areas (LGAs) of Ogun State had been evaluated during a two year field survey. Six month old rice plants were observed for symptom expression and leaf samples collected for serological indexing. Of the 60 leaf ...

  5. Marker-assisted backcrossing: a useful method for rice improvement.

    Science.gov (United States)

    Hasan, Muhammad Mahmudul; Rafii, Mohd Y; Ismail, Mohd R; Mahmood, Maziah; Rahim, Harun A; Alam, Md Amirul; Ashkani, Sadegh; Malek, Md Abdul; Latif, Mohammad Abdul

    2015-03-04

    The world's population is increasing very rapidly, reducing the cultivable land of rice, decreasing table water, emerging new diseases and pests, and the climate changes are major issues that must be addressed to researchers to develop sustainable crop varieties with resistance to biotic and abiotic stresses. However, recent scientific discoveries and advances particularly in genetics, genomics and crop physiology have opened up new opportunities to reduce the impact of these stresses which would have been difficult if not impossible as recently as the turn of the century. Marker assisted backcrossing (MABC) is one of the most promising approaches is the use of molecular markers to identify and select genes controlling resistance to those factors. Regarding this, MABC can contribute to develop resistant or high-yielding or quality rice varieties by incorporating a gene of interest into an elite variety which is already well adapted by the farmers. MABC is newly developed efficient tool by which using large population sizes (400 or more plants) for the backcross F 1 generations, it is possible to recover the recurrent parent genotype using only two or three backcrosses. So far, many high yielding, biotic and abiotic stresses tolerance, quality and fragrance rice varieties have been developed in rice growing countries through MABC within the shortest timeframe. Nowadays, MABC is being used widely in plant breeding programmes to develop new variety/lines especially in rice. This paper reviews recent literature on some examples of variety/ line development using MABC strategy.

  6. Application of gamma-ray irradiation technique to select, create and develop super rice with high quality to substitute the imported hybrid rice

    International Nuclear Information System (INIS)

    Tran Duy Quy; Tran Duy Vuong; Tran Duy Duong; Bui Huy Thuc

    2015-01-01

    Three varieties NPT3, BQ and TQ14 were selected by irradiation ray source Gamma Co-60 with dry seed, 13% grain moisture and created at 25-30 krad. NPT3 is super rice varieties with characteristics such as: extremely short growing period (105-110 day crop; 130- 135 days in the spring, the average yield of 9-10 tones/ha), quality, stem, leaf stand, suitable for intensive capability, able to resist pests and unfavorable conditions especially the elements of productivity (amylase from 15-16%) and mass produced including hybrid rice as Nhi Uu 868, Thien Nguyen Uu 9, HYT100, etc. BQ rice varieties were high quality, average productivity gain of 7.5- 8.0 ton/ha, equivalent to hybrid rice, short growth period (105-110 days in summer season; 120- 130 days in spring season), and quality rice: content 18-20% amylose, rice delicious, supple as BC15. TQ14 varieties was planted in 2 seasons/ year, with agricultural and biological characteristics as Khang-Dan18 mutant with wide adaptation, high yield potential, the average gain from 5.9 to 6.2 tones/ha, short growth period (105-110 days in summer season, 130-135 days in spring season), insect resistance, quality of rice suitable for manufacturing technology like noodles, instant noodles, rice noodles, Ethanol. (author)

  7. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Science.gov (United States)

    2010-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice...

  8. Safety assessment of lepidopteran insect-protected transgenic rice with cry2A* gene.

    Science.gov (United States)

    Zou, Shiying; Huang, Kunlun; Xu, Wentao; Luo, Yunbo; He, Xiaoyun

    2016-04-01

    Numerous genetically modified (GM) crops expressing proteins for insect resistance have been commercialized following extensive testing demonstrating that the foods obtained from them are as safe as that obtained from their corresponding non-GM varieties. In this paper, we report the outcome of safety studies conducted on a newly developed insect-resistant GM rice expressing the cry2A* gene by a subchronic oral toxicity study on rats. GM rice and non-GM rice were incorporated into the diet at levels of 30, 50, and 70% (w/w), No treatment-related adverse or toxic effects were observed based on an examination of the daily clinical signs, body weight, food consumption, hematology, serum biochemistry, and organ weight or based on gross and histopathological examination. These results demonstrate that the GM rice with cry2A* gene is as safe for food as conventional non-GM rice.

  9. Extraction of rice bran oil from local rice husk

    International Nuclear Information System (INIS)

    Anwar, J.; Zaman, W.; Salman, M.; Jabeen, N.

    2006-01-01

    Rice Bran Oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In the present work, extraction of rice bran oil from different samples of rice husk collected from local rice shellers by solvent extraction method has been studied. Experiments were conducted using a soxhelt apparatus, to extract rice bran oil using hexane, petroleum ether, ethanol and methanol as the solvents and the yields obtained under different conditions were compared. Batch extraction tests showed that the rate of extraction decreases with time and the solution approaches saturation at an exponential rate. (author)

  10. Effects of Salt Stress on Germination and Early Seedling Growth of Some Kenyan Rice Cultivars

    International Nuclear Information System (INIS)

    Ochieng, C.A.; Onkware, A.O.

    1999-01-01

    Four rice cultivars (Basmati-217, BW-196, Sindano and Ita-310) were subjected to increasing substrate salinity (0-1.5 Sm -1 ECe), under both laboratory and soil experiments. The salt stress significantly (P -1 ECe) completely inhibited germination in potted soil, but not petri dish tests in the laboratory.It was concluded that the three rice cultivars are susceptible to even mild substrate salinity, and cannot be relied upon for cultivation in saline soils. There is a need to assess the response many of the rice cvv for resistance to salt stress, and, if possible isolate and develop high yielding, resistant cultivars

  11. Gasification of rice husks

    Energy Technology Data Exchange (ETDEWEB)

    Marzetti, P. (ENEA, Rome (Italy). Dipt. Fonti Alternative e Risparmio Energetico)

    The paper outlines the thermochemical processes and equipment involved in the gasification of rice husks. An assessment is made of the feasibility (availability, technology requirements, economics of production and marketing) of this renewable energy source. Results, reported here in tabular form, of experimental trials at an Italian pilot plant (producing, with the use of 165 kg/h of rice husks, 350,000 kcal/h of gas with a conversion yield of 70%) indicated good feasibility. More research is required to improve the combustion qualities of the final product.

  12. Application of induced mutations and modern technologies for rice improvement at the Philippine Rice Research Institute (PhilRice)

    International Nuclear Information System (INIS)

    Padolina, Thelma F.

    2015-01-01

    The application of mutation techniques, i.e. gamma rays and other physical and chemical mutagens has generated a vast amount of genetic variability and has played a significant role in plant breeding and genetics. The widespread use of mutation techniques in plant breeding programs throughout the world has led to the official release of more than 3000 mutant varieties from different plant species. These varieties provide higher yields, better quality, resistance to diseases and resilience to climate change and variability. In the Philippine Rice Research Institute (PhilRice), classical induced mutagenesis and/or in combination with modern technologies as an important tool in rice breeding have been widely utilized by breeders. These recent advances offered new and exciting challenges for the development of new varieties. Moreover, it has the advantage of free regulatory restrictions imposed on genetically modified organisms. To date, high generation of new varieties, elite lines and pre-breeding materials have been derived from chemical and physical mutagenesis, another culture, in vitro mutagenesis, and molecular marker technologies. Directly benefitting the farmers are three Philippine released varieties: PSB Rc78 developed through gamma ray induction in year 2000; and NSIC Rc272 (2011) and Rc346 (2013) developed by combination of Co60 induction and another culture technology. These varieties are intended for the lowlands. In the current works, diverse mutant lines and pre-breeding materials of different target traits were generated and are now under evaluation as potential varieties and/or for use in the inbred and hybrid breeding programs. These genetic materials are in the background of traditional and modern rice varieties. Accordingly, for inbreds, mutated traits ranged from changes in morphological traits, yield, maturity, grain quality, nutritional traits, abiotic resistance such as heat, salinity, and drought tolerance, biotic resistance such as bacterial

  13. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  14. Introduction and Utilization of INGER Rice Germplasm in China

    Institute of Scientific and Technical Information of China (English)

    TANGSheng-xiang; WEIXing-hua; ELJavier

    2004-01-01

    The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5 million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

  15. Introduction and Utilization of INGER Rice Germplasm in China

    Institute of Scientific and Technical Information of China (English)

    TANG Sheng-xiang; WEI Xing-hua; E L Javier

    2004-01-01

    The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

  16. Competição entre plantas de arroz e biótipos de capim-arroz (Echinochloa spp. resistente e suscetível ao quinclorac Competition between rice plants and Echinochloa spp. biotypes resistant or susceptible to quinclorac

    Directory of Open Access Journals (Sweden)

    L. Galon

    2009-01-01

    Full Text Available Objetivou-se com este trabalho avaliar a competitividade interespecífica de biótipos de capim-arroz resistente (R e suscetível (S ao herbicida quinclorac com a cultura do arroz irrigado. O experimento foi instalado em casa de vegetação e os tratamentos consistiram em manter uma planta de arroz cv. BRS Pelota no centro da unidade experimental, variando-se na periferia as densidades de capim-arroz em: 0, 1, 2, 3, 4 ou 5 plantas do biótipo R (ITJ-13 ou S (ITJ-17 oriundos da região de Itajaí-SC. O delineamento experimental utilizado foi o completamente casualizado, em esquema fatorial 2 x 6 com quatro repetições. Aos 40 dias após a emergência, foram avaliados as massas fresca e seca e o conteúdo de água de folhas, colmos e total da parte aérea do arroz e do capim-arroz. Houve efeito significativo dos tratamentos para todas as variáveis estudadas quando a cultura do arroz foi cultivada na presença de biótipos de capim-arroz R ou S. Esse efeito foi aditivo na proporção de 1 planta m-2. Entretanto, a capacidade competitiva dos biótipos de capim-arroz resistente e suscetível ao quinclorac, com as plantas de arroz, apresentou comportamento similar quando se variou a densidade de plantas por área.This work aimed to evaluate the interspecific competitiveness of Echinochloa spp. biotypes resistant or susceptible to the herbicide quinclorac. The trial was installed under greenhouse conditions, with the biotypes resistant (ITJ-13 and susceptible (ITJ-17 to quinclorac under competition with the rice plants. The treatments consisted of maintaining one rice plant at the center of the experimental unit, surrounded by 0, 1, 2, 3, 4 or 5 Echinochloa plants, according to the treatment. The trial was arranged in a completely randomized blocks design and factorial scheme 2 x 6, with four replications. Forty days after emergence, fresh dry weights and water content of the shoots were evaluated. There was a significant effect for all the variables

  17. RICE-HUSK ASH-CARBIDE-WASTE STABILIZATION OF ...

    African Journals Online (AJOL)

    This paper present results of the laboratory evaluation of the characteristics of carbide waste and rice husk ash stabilized reclaimed asphalt pavement waste with a ... of 5.7 % and resistance to loss in strength of 84.1 %, hence the recommendation of the mixture for use as sub-base material in flexible pavement construction.

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

    Science.gov (United States)

    In this research, we investigated the accumulation of arsenic (As), selenium (Se), molybdenum (Mo), and cadmium (Cd) in rice grain under different soil conditions in standard straighthead-resistant and straighthead-susceptible cultivars, Zhe 733 and Cocodrie, respectively. Results demonstrated that,...

  19. Comparative Transcriptome Analysis of Salivary Glands of Two Populations of Rice Brown Planthopper, Nilaparvata lugens, That Differ in Virulence

    OpenAIRE

    Ji, Rui; Yu, Haixin; Fu, Qiang; Chen, Hongdan; Ye, Wenfeng; Li, Shaohui; Lou, Yonggen

    2013-01-01

    BACKGROUND: The brown planthopper (BPH), Nilaparvata lugens (Stål), a destructive rice pest in Asia, can quickly overcome rice resistance by evolving new virulent populations. Herbivore saliva plays an important role in plant-herbivore interactions, including in plant defense and herbivore virulence. However, thus far little is known about BPH saliva at the molecular level, especially its role in virulence and BPH-rice interaction. METHODOLOGY/PRINCIPAL FINDINGS: Using cDNA amplification in c...

  20. Studies on changes in fatty acid composition and content of endogenous antioxidants during gamma irradiation of rice seeds

    International Nuclear Information System (INIS)

    Ramarathnam, N.; Osawa, T.; Namiki, M.; Kawakishi, S.

    1989-01-01

    Accelerated aging effects, induced by y irradiation, were investigated on the fatty acid composition of lipids and on the content of endogenous antioxidants of four Indica and four Japonica rice seeds with and without intact hull. While the linoleic acid content of the phospholipids decreased gradually with the increase in irradiation doses, there was a corresponding increase in the linoleic acid content of the free fatty acids. Such changes were drastic, especially in the case of Japonica rice seeds irradiated without intact hull. However, the neutral lipids were found to be resistant to γ irradiation. The α-tocopherol content was found to decrease (markedly) in rice seeds irradiated with or without hull, especially in the Japonica rice seeds. At a dose of 15 kGy only traces of a-tocopherol could be detected in Japonica and Indica rice seeds irradiated with and without intact hull. Oryzanol, a relatively weaker anti-oxidant, was found to be more resistant to oxidative damage than a-tocopherol. At 15 kGy, the oryzanol content ranged from 59 μg to 170 μg/g lipid in rice seeds irradiated with intact hull, while the corresponding value for rice seeds irradiated without hull was 52 μg to 153 μg/g lipid. The overall susceptibility to oxidative damage was less in Indica rice seeds, indicating that the antioxidative defense system offered better protection in overcoming oxidative stress in Indica rice hull than in Japonica rice hull

  1. Rice as commodity and anti-commodity

    NARCIS (Netherlands)

    Richards, P.

    2016-01-01

    On the Upper West Africa coast rice belongs to two species — African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.). African rice was domesticated in the region, perhaps three millennia ago, from a presumed wild ancestor, O. barthii. Asian rice was introduced via trans-Saharan

  2. Diseases of wild rice

    Science.gov (United States)

    Diseases are much more pronounced in cultivated wild rice than in natural stands, most likely due to the narrower genetic base of the populations, plant stress due to high planting density and floodwater removal prior to harvest, and high relative humidity in the plant canopy. Yield losses occur as ...

  3. Promising rice mutants

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1988-01-01

    Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

  4. Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

    Science.gov (United States)

    Kukusamude, C.; Kongsri, S.

    2017-10-01

    We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sungyod rice). Thai jasmine rice and Sungyod rice were cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sungyod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali 105) was cultivated from Thung Kula Rong Hai area, whereas Sungyod rice was cultivated from Phathalung province. Hypothesis testing of difference of each isotope between Thai jasmine rice and Sungyod rice was also studied. The study was the feasibility test whether the light stable isotopes can be the variables to identify Thai jasmine rice and Sungyod rice. The result shows that there was difference in the isotope patterns of Thai jasmine rice and Sungyod rice. Our results may provide the useful information in term of stable isotope profiles of Thai rice.

  5. Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

    Directory of Open Access Journals (Sweden)

    Simon Swapna

    2017-09-01

    Full Text Available Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000, and followed by the pot planted experiments in the rain-out-zone. The activities of antioxidant enzymes, relative water content, cell membrane stability, photosynthetic pigments, proline content, along with plant growth parameters of the varieties under drought condition were evaluated. Moreover, the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice. Among the 42 rice varieties, we identified 2 rice varieties, Swarnaprabha and Kattamodan, with less leaf rolling, better drought recovery ability as well as relative water content, increased membrane stability index, osmolyte accumulation, and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress. The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.

  6. A novel reference plasmid for the qualitative detection of genetically modified rice in food and feed.

    Science.gov (United States)

    Li, Liang; Dong, Mei; An, Na; Liang, Lixia; Wan, Yusong; Jin, Wujun

    2015-01-01

    Rice is one of the most important food crops in the world. Genetically modified (GM) technology has been used in rice to confer herbicide tolerance and pathogen or insect resistance. China invests heavily in research on GM rice. By the end of 2014, at least 250 transgenic rice lines had been developed in China. To monitor the presence of GM rice in food and feed, we collected information on foreign elements from 250 transgenic rice lines and found 5 elements, including the Agrobacterium tumefaciens nopaline synthase terminator (T-NOS), the cauliflower mosaic virus 35S promoter (CaMV35S), the ubiquitin gene (Ubi), the bar gene, and the hygromycin phosphotransferase gene (Hpt), that are commonly present in GM rice. Therefore, we constructed a novel plasmid (pBJGMM001) that contains fragments of these elements and two endogenous reference genes (the sucrose phosphate synthase gene, SPS, and the phosphoenolpyruvate carboxylase gene, PEPC). pBJGMM001 can serve as a standard for detecting 96% of GM rice lines in China. The primers, amplicons, reaction mixture, and PCR program were developed based on Chinese National Standards. The protocol was validated and determined to be suitable for practical use in monitoring and identifying GM rice.

  7. A Novel Reference Plasmid for the Qualitative Detection of Genetically Modified Rice in Food and Feed

    Directory of Open Access Journals (Sweden)

    Liang Li

    2015-01-01

    Full Text Available Rice is one of the most important food crops in the world. Genetically modified (GM technology has been used in rice to confer herbicide tolerance and pathogen or insect resistance. China invests heavily in research on GM rice. By the end of 2014, at least 250 transgenic rice lines had been developed in China. To monitor the presence of GM rice in food and feed, we collected information on foreign elements from 250 transgenic rice lines and found 5 elements, including the Agrobacterium tumefaciens nopaline synthase terminator (T-NOS, the cauliflower mosaic virus 35S promoter (CaMV35S, the ubiquitin gene (Ubi, the bar gene, and the hygromycin phosphotransferase gene (Hpt, that are commonly present in GM rice. Therefore, we constructed a novel plasmid (pBJGMM001 that contains fragments of these elements and two endogenous reference genes (the sucrose phosphate synthase gene, SPS, and the phosphoenolpyruvate carboxylase gene, PEPC. pBJGMM001 can serve as a standard for detecting 96% of GM rice lines in China. The primers, amplicons, reaction mixture, and PCR program were developed based on Chinese National Standards. The protocol was validated and determined to be suitable for practical use in monitoring and identifying GM rice.

  8. Radiation disinfestation of Basmati rice

    International Nuclear Information System (INIS)

    Rao, V.S.; Gholap, A.S.; Adhikari, H.R.; Nair, P.M.

    1994-01-01

    Effect of low dose γ-radiation on prepackaged Basmati rice was studied in order to achieve disinfestation of rice. Basmati rice procured from local market was repacked in 1 kg pouches made from high density polyethylene (HDP) and biaxially oriented polypropylene: low density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25-1.0 kGy. Within one month of storage at room temperature, unirradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted due to irradiation in the functional properties of rice such as swelling index and water absorption and in total volatile components responsible for flavour of Basmati rice. In organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses at present due to infestation. (author). 24 refs., 5 tabs., 1 fig

  9. Assessment of reference gene stability in Rice stripe virus and Rice black streaked dwarf virus infection rice by quantitative Real-time PCR.

    Science.gov (United States)

    Fang, Peng; Lu, Rongfei; Sun, Feng; Lan, Ying; Shen, Wenbiao; Du, Linlin; Zhou, Yijun; Zhou, Tong

    2015-10-24

    Stably expressed reference gene(s) normalization is important for the understanding of gene expression patterns by quantitative Real-time PCR (RT-qPCR), particularly for Rice stripe virus (RSV) and Rice black streaked dwarf virus (RBSDV) that caused seriously damage on rice plants in China and Southeast Asia. The expression of fourteen common used reference genes of Oryza sativa L. were evaluated by RT-qPCR in RSV and RBSDV infected rice plants. Suitable normalization reference gene(s) were identified by geNorm and NormFinder algorithms. UBQ 10 + GAPDH and UBC + Actin1 were identified as suitable reference genes for RT-qPCR normalization under RSV and RBSDV infection, respectively. When using multiple reference genes, the expression patterns of OsPRIb and OsWRKY, two virus resistance genes, were approximately similar with that reported previously. Comparatively, by using single reference gene (TIP41-Like), a weaker inducible response was observed. We proposed that the combination of two reference genes could obtain more accurate and reliable normalization of RT-qPCR results in RSV- and RBSDV-infected plants. This work therefore sheds light on establishing a standardized RT-qPCR procedure in RSV- and RBSDV-infected rice plants, and might serve as an important point for discovering complex regulatory networks and identifying genes relevant to biological processes or implicated in virus.

  10. Induction of drought tolerant mutants of rice

    International Nuclear Information System (INIS)

    El-Hissewy, A.A.; Abd Allah, A.

    2001-01-01

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

  11. Breeding of a new special rice variety Hangxiangnuo

    International Nuclear Information System (INIS)

    Zhou Hanqin; Pang Dajian; Fan Zhilan; Liu Chuanguang; Li Chen; Chen Jianyou

    2011-01-01

    A new special rice variety Hangxiangnuo was bred by several generation selections of the progeny of the rice variety Nanfengnuo which was carried by the spacecraft Shenzhou No 4. Hangxiangnuo was permitted to release by the Crop Examination and Approval Committee of Guangdong Province in January, 2009. Compared with its parent variety Nanfengnuo, Hangxiangnuo has better resistance to blast, greater length-width ratio of grain, more panicles per plant, filled grains per panicle and fragrance. The efficiency of space mutation breeding and the generation at which mutant traits become homozygous were also discussed in the paper. (authors)

  12. Improvement of rice through induced mutations

    International Nuclear Information System (INIS)

    Miah, A.J.; Mansur, M.A.; Jalal Uddin, M.

    1981-01-01

    In a field trial conducted in randomized blocks with 4 replications during November to April 1977-78, 4 radiation-induced mutants of rice (Oryza sativa Linn.) were found to be 23 to 41 days earlier than 'IR 8'. 'Mut 1-2' gave the highest grain yield (2,884 kg/ha), followed by 'Mut 1-1' (2, 183 kg/ha) and 'BR 3' (1,825 kg/ha). Though all the mutant lines were suceptible to bacterial leaf-blight in greenhouse, in the field 'Mut 1-2' was moderately resistant and 'Mut 1-1' moderately susceptible. (auth.)

  13. Genetic analysis and identification of SSR markers associated with rice blast disease in a BC2F1 backcross population.

    Science.gov (United States)

    Hasan, N; Rafii, M Y; Abdul Rahim, H; Nusaibah, S A; Mazlan, N; Abdullah, S

    2017-01-23

    Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are