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

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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.

The chloroplast-localized phospholipases D α4 and α5 regulate herbivore-induced direct and indirect defenses in rice.

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Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-12-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice.

γ-Oryzanol-Rich Black Rice Bran Extract Enhances the Innate Immune Response.

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Shin, Soon Young; Kim, Heon-Woong; Jang, Hwan-Hee; Hwang, Yu-Jin; Choe, Jeong-Sook; Lim, Yoongho; Kim, Jung-Bong; Lee, Young Han

2017-09-01

The innate immune response is an important host primary defense system against pathogens. γ-Oryzanol is one of the nutritionally important phytoceutical components in rice bran oil. The goal of this study was to investigate the effect of γ-oryzanol-rich extract from black rice bran (γORE) on the activation of the innate immune system. In this study, we show that γORE increased the expression of CD14 and Toll-like receptor 4 and enhanced the phagocytic activity of RAW264.7 macrophages. Furthermore, γORE and its active ingredient γ-oryzanol promoted the secretion of innate cytokines, interleukin-8, and CCL2, which facilitate phagocytosis by RAW264.7 cells. These findings suggest that γ-oryzanol in the γORE enhances innate immune responses.

The Commonly Used Bactericide Bismerthiazol Promotes Rice Defenses against Herbivores

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Pengyong Zhou

2018-04-01

Full Text Available Chemical elicitors that enhance plant resistance to pathogens have been extensively studied, however, chemical elicitors that induce plant defenses against insect pests have received little attention. Here, we found that the exogenous application of a commonly used bactericide, bismerthiazol, on rice induced the biosynthesis of constitutive and/or elicited jasmonic acid (JA, jasmonoyl-isoleucine conjugate (JA-Ile, ethylene and H2O2 but not salicylic acid. These activated signaling pathways altered the volatile profile of rice plants. White-backed planthopper (WBPH, Sogatella furcifera nymphs and gravid females showed a preference for feeding and/or oviposition on control plants: survival rates were better and more eggs were laid than on bismerthiazol-treated plants. Moreover, bismerthiazol treatment also increased both the parasitism rate of WBPH eggs laid on plants in the field by Anagrus nilaparvatae, and also the resistance of rice to the brown planthopper (BPH Nilaparvata lugens and the striped stem borer (SSB Chilo suppressalis. These findings suggest that the bactericide bismerthiazol can induce the direct and/or indirect resistance of rice to multiple insect pests, and so can be used as a broad-spectrum chemical elicitor.

Thiamine primed defense provides reliable alternative to systemic fungicide carbendazim against sheath blight disease in rice (Oryza sativa L.).

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Bahuguna, Rajeev Nayan; Joshi, Rohit; Shukla, Alok; Pandey, Mayank; Kumar, J

2012-08-01

A novel pathogen defense strategy by thiamine priming was evaluated for its efficacy against sheath blight pathogen, Rhizoctonia solani AG-1A, of rice and compared with that of systemic fungicide, carbendazim (BCM). Seeds of semidwarf, high yielding, basmati rice variety Vasumati were treated with thiamine (50 mM) and BCM (4 mM). The pot cultured plants were challenge inoculated with R. solani after 40 days of sowing and effect of thiamine and BCM on rice growth and yield traits was examined. Higher hydrogen peroxide content, total phenolics accumulation, phenylalanine ammonia lyase (PAL) activity and superoxide dismutase (SOD) activity under thiamine treatment displayed elevated level of systemic resistance, which was further augmented under challenging pathogen infection. High transcript level of phenylalanine ammonia lyase (PAL) and manganese superoxide dismutase (MnSOD) validated mode of thiamine primed defense. Though minimum disease severity was observed under BCM treatment, thiamine produced comparable results, with 18.12 per cent lower efficacy. Along with fortifying defense components and minor influence on photosynthetic pigments and nitrate reductase (NR) activity, thiamine treatment significantly reduced pathogen-induced loss in photosynthesis, stomatal conductance, chlorophyll fluorescence, NR activity and NR transcript level. Physiological traits affected under pathogen infection were found signatory for characterizing plant's response under disease and were detectable at early stage of infection. These findings provide a novel paradigm for developing alternative, environmentally safe strategies to control plant diseases. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.

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Alamgir, Kabir Md; Hojo, Yuko; Christeller, John T; Fukumoto, Kaori; Isshiki, Ryutaro; Shinya, Tomonori; Baldwin, Ian T; Galis, Ivan

2016-02-01

Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants. © 2015 John Wiley & Sons Ltd.

The Commonly Used Bactericide Bismerthiazol Promotes Rice Defenses against Herbivores

OpenAIRE

Pengyong Zhou; Xiaochang Mo; Wanwan Wang; Xia Chen; Yonggen Lou

2018-01-01

Chemical elicitors that enhance plant resistance to pathogens have been extensively studied, however, chemical elicitors that induce plant defenses against insect pests have received little attention. Here, we found that the exogenous application of a commonly used bactericide, bismerthiazol, on rice induced the biosynthesis of constitutive and/or elicited jasmonic acid (JA), jasmonoyl-isoleucine conjugate (JA-Ile), ethylene and H2O2 but not salicylic acid. These activated signaling pathways ...

The Chloroplast-Localized Phospholipases D α4 and α5 Regulate Herbivore-Induced Direct and Indirect Defenses in Rice1[C][W

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Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-01-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice. PMID:21984727

Two rice GRAS family genes responsive to N -acetylchitooligosaccharide elicitor are induced by phytoactive gibberellins: evidence for cross-talk between elicitor and gibberellin signaling in rice cells.

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Day, R Bradley; Tanabe, Shigeru; Koshioka, Masaji; Mitsui, Toshiaki; Itoh, Hironori; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Kaku, Hanae; Shibuya, Naoto; Minami, Eiichi

2004-01-01

In this study, we present data showing that two members of the GRAS family of genes from rice, CIGR1 and CIGR2 (chitin-inducible gibberellin-responsive), inducible by the potent elicitor N -acetylchitooligosaccharide (GN), are rapidly induced by exogenous gibberellins. The pattern of mRNA accumulation was dependent on the dose and biological activity of the gibberellins, suggesting that the induction of the genes by gibberellin is mediated by a biological receptor capable of specific recognition and signal transduction upon perception of the phytoactive compounds. Further pharmacological analysis revealed that the CIGR1 and CIGR2 mRNA accumulation by treatment with gibberellin is dependent upon protein phosphorylation/dephosphorylation events. In rice calli derived from slender rice 1, a constitutive gibberellin-responsive mutant, or d1, a mutant deficient in the alpha -subunit of the heterotrimeric G-protein, CIGR1 and CIGR2 were induced by a GN elicitor, yet not by gibberellin. Neither gibberellin nor GN showed related activities in defense or development, respectively. These results strongly suggested that the signal transduction cascade from gibberellin is independent of that from GN, and further implied that CIGR1 and CIGR2 have dual, distinct roles in defense and development.

Jasmonates induce both defense responses and communication in monocotyledonous and dicotyledonous plants.

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Okada, Kazunori; Abe, Hiroshi; Arimura, Gen-ichiro

2015-01-01

Jasmonic acid (JA) and its derivatives (jasmonates, JAs) are phytohormones with essential roles in plant defense against pathogenesis and herbivorous arthropods. Both the up- and down-regulation of defense responses are dependent on signaling pathways mediated by JAs as well as other stress hormones (e.g. salicylic acid), generally those involving the transcriptional and post-transcriptional regulation of transcription factors via protein modification and epigenetic regulation. In addition to the typical model plant Arabidopsis (a dicotyledon), advances in genetics research have made rice a model monocot in which innovative pest control traits can be introduced and whose JA signaling pathway can be studied. In this review, we introduce the dynamic functions of JAs in plant defense strategy using defensive substances (e.g. indole alkaloids and terpenoid phytoalexins) and airborne signals (e.g. green leaf volatiles and volatile terpenes) in response to biotrophic and necrotrophic pathogens as well as above-ground and below-ground herbivores. We then discuss the important issue of how the mutualism of herbivorous arthropods with viruses or bacteria can cause cross-talk between JA and other phytohormones to counter the defense systems. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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

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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.

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

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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

Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes

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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

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

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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

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

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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.

Antioxidant Defense Mechanisms of Salinity Tolerance in Rice Genotypes

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Mohammad Golam Kibria

2017-05-01

Full Text Available In order to elucidate the role of antioxidant responses in salinity tolerance in rice genotypes under salt stress, experiments were conducted using four rice varieties, including salt-sensitive BRRI dhan 28 and three salt-tolerant varieties BRRI dhan 47, BINA dhan 8 and BINA dhan 10. Thirty-day-old rice seedlings were transplanted into pots. At the active tillering stage (35 d after transplanting, plants were exposed to different salinity levels (0, 20, 40 and 60 mmol/L NaCl. Salt stress caused a significant reduction in growth for all the rice genotypes. Growth reduction was higher in the salt-sensitive genotype than in the salt-tolerant ones, and BINA dhan 10 showed higher salt tolerance in all measured physiological parameters. The reduction in shoot and root biomass was found to be minimal in BINA dhan 10. Chlorophyll content significantly decreased under salt stress except for BINA dhan 10. Proline content significantly increased in salt-tolerant rice genotypes with increased salt concentration, and the highest proline content was obtained from BINA dhan 10 under salt stress. Catalase and ascorbate peroxidase activities significantly decreased in salt-sensitive genotype whereas significantly increased in salt-tolerant ones with increasing salt concentration. However, salt stress significantly decreased guaiacol peroxidase activity in all the rice genotypes irrespective of salt tolerance. K+/Na+ ratio also significantly decreased in shoots and roots of all the rice genotypes. The salt-tolerant genotype BINA dhan 10 maintained higher levels of chlorophyll and proline contents as well as catalase and ascorbate peroxidase activities under salt stress, thus, this might be the underlying mechanism for salt tolerance.

Response Of Lowland Rice To Soil Compaction

International Nuclear Information System (INIS)

Idawati; Haryanto

2000-01-01

Soil compaction, as a new tillage practice for paddy soil, is to substitute pudding in order to reduce land preparation cost. To study response of lowland rice to soil compaction, a pot experiment has been conducted which took place in the greenhouse of P3TIR-BATAN. Soil for experiment was taken from pusakanegara. Two factors (degree of soil compaction and rice variety) were combined. Degree of compaction was split into 3 levels (DI = normal; D215% more compact than normal; 30 % more compact than normal), and rice variety into 2 levels (IR64 and Atomita IV). KH 2 32 PO 4 solution was injected into the soil surrounding rice clump to test the root activity at blooming stage of rice plant. Data resulted from this experiment is presented together with additional data from some other experiments of fertilization in the research s erie to study soil compaction. Some information's from experiment results are as following. Both rice varieties tested gave the same response to soil compaction. Root activity, according to data of 32 P absorbed by plant, was not harmed by soil compaction at the degree tested in the experiment. This prediction is supported by the growth by rice observed at generative growth stage, in pot experiment as well as in field experiment, which showed that soil compaction tested did not decrease rice yield but in opposite in tended to increase the yield. In practising soil compaction in land preparation, fertilizers should be applied by deep placement to have higher increasing is rice yield

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

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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.

Identification of gibberellin acid-responsive proteins in rice leaf sheath using proteomics.

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Gu, Jia-Yu; Wang, Ye; Zhang, Xu; Zhang, Shi-Hua; Gao, Yin; An, Cheng-Cai

2010-06-01

The phytohormone gibberellin acid (GA) controls many aspects of plant development. In this study, we identified proteins that are differentially expressed between the rice (Oryza sativa L.) GA-deficient cultivar, Aijiaonante, and its parental line, Nante. Proteins were extracted from rice leaf sheath and examined by 2DGE. Among more than 1200 protein spots reproducibly detected on each gel, 29 were found to be highly up-regulated by GAs in Nante, and 6 were down-regulated by GAs in Aijiaonante. These 35 proteins were identified by MALDI-TOF MS and were classified into three groups based on their putative function in metabolism, stress/defense processes and signal transduction. These data suggest that metabolic pathways are the main target of regulation by GAs during rice development. Our results provide new information about the involvement of GAs in rice development.

Allelopathic Responses of Rice Seedlings under Some Different Stresses

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Tran Dang Khanh

2018-05-01

Full Text Available The objective of this study was to evaluate the allelopathic responses of rice seedlings under submergence stress at different temperatures (10, 25, 32, and 37 °C. The results showed that a wide range of allelopathic responses of rice seedlings depended on varieties and stress conditions, with temperature was being a key factor. It showed that the extracts of rice seedlings induced significant suppression on lettuce and radish seedling germination, but had negligible allelopathic effects on growth of barnyardgrass, whilst the emergence and growth of natural weeds was stimulated. In contrast, the root exudates of Koshihikari rice seedlings (K32 at 32 °C reduced the number of total weeds by ≈60.0% and the total dry weight of weeds by 93.0%; i.e., to a greater extent than other root exudates. Among the 13 identified phenolic acids, p-hydroxybenzoic, vanillic, syringic, sinapic and benzoic acids—at concentrations of 0.360, 0.045, 3.052, 1.309 and 5.543 μg/mL might be involved in allelopathic responses of K32, inhibiting the growth of barnyardgrass and natural weeds. Findings of the present study may provide useful information on allelopathic responses of rice under environmental stresses and thus further understand of the competitive relationships between rice and weeds under natural conditions.

Label-Free Quantitative Proteomic Analysis of Chitosan Oligosaccharide-Treated Rice Infected with Southern Rice Black-Streaked Dwarf Virus.

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Yang, Anming; Yu, Lu; Chen, Zhuo; Zhang, Shanxue; Shi, Jing; Zhao, Xiaozhen; Yang, Yuanyou; Hu, Deyu; Song, Baoan

2017-05-18

Southern rice black-streaked dwarf virus (SRBSDV) has spread from thesouth of China to the north of Vietnam in the past few years and severelyinfluenced rice production. Its long incubation period and early symptoms are not evident; thus, controlling it is difficult. Chitosan oligosaccharide (COS) is a green plant immunomodulator. Early studies showed that preventing and controlling SRBSDV have a certain effect and reduce disease infection rate, but its underlying controlling and preventing mechanism is unclear. In this study, label-free proteomics was used to analyze differentially expressed proteins in rice after COS treatment. The results showed that COS can up-regulate the plant defense-related proteins and down-regulate the protein expression levels of SRBSDV. Meanwhile, quantitative real-time PCR test results showed that COS can improve defense gene expression in rice. Moreover, COS can enhance the defense enzymatic activities of peroxidase, superoxide dismutase and catalase through mitogen-activated protein kinase signaling cascade pathway, and enhance the rice disease resistance.

Elucidation of complex nature of PEG induced drought-stress response in rice root using comparative proteomics approach

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Lalit Agrawal

2016-09-01

Full Text Available Along with many adaptive strategies, dynamic changes in protein abundance seem to be the common strategy to cope up with abiotic stresses which can be best explored through proteomics. Understanding of drought response is the key to decipher regulatory mechanism of better adaptation. Rice (Oryza sativa L. proteome represents a phenomenal source of proteins that govern traits of agronomic importance, such as drought tolerance. In this study, a comparison of root cytoplasmic proteome was done for a drought tolerant rice (Heena cultivar in PEG induced drought conditions. A total of 510 protein spots were observed by PDQuest analysis and 125 differentially regulated spots were subjected for MALDI-TOF MS-MS analysis out of which 102 protein spots identified which further led to identification of 78 proteins with a significant score. These 78 differentially expressed proteins appeared to be involved in different biological pathways. The largest percentage of identified proteins was involved in bioenergy and metabolism (29% and mainly consists of malate dehydrogenase, succinyl-CoA, putative acetyl-CoA synthetase and pyruvate dehydrogenase etc. This was followed by proteins related to cell defense and rescue (22% such as monodehydroascorbate reductase and stress-induced protein sti1, then by protein biogenesis and storage class (21% e.g. putative thiamine biosynthesis protein, putative beta-alanine synthase and cysteine synthase. Further, cell signaling (9% proteins like actin and prolyl endopeptidase and proteins with miscellaneous function (19% like Sgt1 and some hypothetical protein were also represented a large contribution towards drought regulatory mechanism in rice. We propose that protein biogenesis, cell defense and superior homeostasis may render better drought-adaptation. These findings might expedite the functional determination of the drought-responsive proteins and their prioritisation as potential molecular targets for perfect adaptation.

The components of rice and watermelon root exudates and their effects on pathogenic fungus and watermelon defense.

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Ren, Lixuan; Huo, Hongwei; Zhang, Fang; Hao, Wenya; Xiao, Liang; Dong, Caixia; Xu, Guohua

2016-06-02

Watermelon (Citrullus lanatus) is susceptible to wilt disease caused by the fungus Fusarium oxysporum f. sp niveum (FON). Intercropping management of watermelon/aerobic rice (Oryza sativa) alleviates watermelon wilt disease, because some unidentified component(s) in rice root exudates suppress FON sporulation and spore germination. Here, we show that the phenolic acid p-coumaric acid is present in rice root exudates only, and it inhibits FON spore germination and sporulation. We found that exogenously applied p-coumaric acid up-regulated the expression of ClPR3 in roots, as well as increased chitinase activity in leaves. Furthermore, exogenously applied p-coumaric acid increased β-1,3-glucanase activity in watermelon roots. By contrast, we found that ferulic acid was secreted by watermelon roots, but not by rice roots, and that it stimulated spore germination and sporulation of FON. Exogenous application of ferulic acid down-regulated ClPR3 expression and inhibited chitinase activity in watermelon leaves. Salicylic acid was detected in both watermelon and rice root exudates, which stimulated FON spore germination at low concentrations and suppressed spore germination at high concentrations. Exogenously applied salicylic acid did not alter ClPR3 expression, but did increase chitinase and β-1,3-glucanase activities in watermelon leaves. Together, our results show that the root exudates of phenolic acids were different between rice and watermelon, which lead to their special ecological roles on pathogenic fungus and watermelon defense.

Rice terpene synthase 24 (OsTPS24) encodes a jasmonate-responsive monoterpene synthase that produces an antibacterial γ-terpinene against rice pathogen.

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Yoshitomi, Kayo; Taniguchi, Shiduku; Tanaka, Keiichiro; Uji, Yuya; Akimitsu, Kazuya; Gomi, Kenji

2016-02-01

Rice is one of the most important crops worldwide and is widely used as a model plant for molecular studies of monocotyledonous species. The plant hormone jasmonic acid (JA) is involved in rice-pathogen interactions. In addition, volatile compounds, including terpenes, whose production is induced by JA, are known to be involved in the rice defense system. In this study, we analyzed the JA-induced terpene synthase OsTPS24 in rice. We found that OsTPS24 was localized in chloroplasts and produced a monoterpene, γ-terpinene. The amount of γ-terpinene increased after JA treatment. γ-Terpinene had significant antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo); however, it did not show significant antifungal activity against Magnaporthe oryzae. The antibacterial activity of the γ-terpinene against Xoo was caused by damage to bacterial cell membranes. These results suggest that γ-terpinene plays an important role in JA-induced resistance against Xoo, and that it functions as an antibacterial compound in rice. Copyright © 2015 Elsevier GmbH. All rights reserved.

Integrative Analysis of the microRNAome and Transcriptome Illuminates the Response of Susceptible Rice Plants to Rice Stripe Virus.

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Jian Yang

Full Text Available Rice stripe virus (RSV is one of the most serious rice viruses in East Asia. To investigate how rice responds to RSV infection, we integrated miRNA expression with parallel mRNA transcription profiling by deep sequencing. A total of 570 miRNAs were identified of which 69 miRNAs (56 up-regulated and 13 down-regulated were significantly modified by RSV infection. Digital gene expression (DGE analysis showed that 1274 mRNAs (431 up-regulated and 843 down-regulated genes were differentially expressed as a result of RSV infection. The differential expression of selected miRNAs and mRNAs was confirmed by qRT-PCR. Gene ontology (GO and pathway enrichment analysis showed that a complex set of miRNA and mRNA networks were selectively regulated by RSV infection. In particular, 63 differentially expressed miRNAs were found to be significantly and negatively correlated with 160 target mRNAs. Interestingly, 22 up-regulated miRNAs were negatively correlated with 24 down-regulated mRNAs encoding disease resistance-related proteins, indicating that the host defense responses were selectively suppressed by RSV infection. The suppression of both osa-miR1423-5p- and osa-miR1870-5p-mediated resistance pathways was further confirmed by qRT-PCR. Chloroplast functions were also targeted by RSV, especially the zeaxanthin cycle, which would affect the stability of thylakoid membranes and the biosynthesis of ABA. All these modifications may contribute to viral symptom development and provide new insights into the pathogenicity mechanisms of RSV.

32 CFR 13.4 - Duties and responsibilities of the defense.

Science.gov (United States)

2010-07-01

... COMMISSIONS RESPONSIBILITIES OF THE CHIEF DEFENSE COUNSEL, DETAILED DEFENSE COUNSEL, AND CIVILIAN DEFENSE COUNSEL § 13.4 Duties and responsibilities of the defense. (a) Regular duties. The Defense shall perform... 32 National Defense 1 2010-07-01 2010-07-01 false Duties and responsibilities of the defense. 13.4...

Gene response in rice plants treated with continuous fog influenced by pH, was similar to that treated with biotic stress.

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Satoh, Kouji; Saji, Shoko; Ito, Shoko; Shimizu, Hideyuki; Saji, Hikaru; Kikuchi, Shoshi

2014-01-01

Throughout Asia, including Japan, rice plants are cultivated in a wide range of areas from lowlands to highlands and are frequently exposed to fog, including acid fog. Some physiological studies have shown that acid fog can be a stress factor for plants. We analyzed the gene expression profiles of rice plants treated with artificially prepared simulated acid fog (SiAF) or simulated neutral fog (SiNF) for 1 or 7 days. Microarray analysis results suggested that both the SiAF and the SiNF treatments induced the expression of genes involved in the defense and stress responses in rice plants. Induction of such genes was detected in plants treated with SiAF for 1 day, and the number of induced genes increased in plants treated with SiAF for 7 days. The genes for defense and stress responses were also induced by SiNF for 7 days, although they were not induced by SiNF for 1 day. The gene expression profiles of the SiAF-treated and the SiNF-treated plants were compared to those of plants treated with other stress factors. The comparison revealed that both SiAF and SiNF treatments have similar effects to biotic stresses and ozone stress. The genes encoding NADPH oxidase and germin, which function in apoplasts, were also induced by SiAF, SiNF and biotic stresses. These findings suggest that both the SiAF and the SiNF treatments may result in oxidative stress through the apoplastic production of reactive oxygen species.

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

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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

Transcriptome profiling confirmed correlations between symptoms and transcriptional changes in RDV infected rice and revealed nucleolus as a possible target of RDV manipulation.

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Yang, Liang; Du, Zhenguo; Gao, Feng; Wu, Kangcheng; Xie, Lianhui; Li, Yi; Wu, Zujian; Wu, Jianguo

2014-05-06

Rice dwarf virus (RDV) is the causal agent of rice dwarf disease, which limits rice production in many areas of south East Asia. Transcriptional changes of rice in response to RDV infection have been characterized by Shimizu et al. and Satoh et al.. Both studies found induction of defense related genes and correlations between transcriptional changes and symptom development in RDV-infected rice. However, the same rice cultivar, namely Nipponbare belonging to the Japonic subspecies of rice was used in both studies. Gene expression changes of the indica subspecies of rice, namely Oryza sativa L. ssp. indica cv Yixiang2292 that show moderate resistance to RDV, in response to RDV infection were characterized using an Affymetrix Rice Genome Array. Differentially expressed genes (DEGs) were classified according to their Gene Ontology (GO) annotation. The effects of transient expression of Pns11 in Nicotiana benthaminana on the expression of nucleolar genes were studied using real-time PCR (RT-PCR). 856 genes involved in defense or other physiological processes were identified to be DEGs, most of which showed up-regulation. Ribosome- and nucleolus related genes were significantly enriched in the DEGs. Representative genes related to nucleolar function exhibited altered expression in N. benthaminana plants transiently expressing Pns11 of RDV. Induction of defense related genes is common for rice infected with RDV. There is a co-relation between symptom severity and transcriptional alteration in RDV infected rice. Besides ribosome, RDV may also target nucleolus to manipulate the translation machinery of rice. Given the tight links between nucleolus and ribosome, it is intriguing to speculate that RDV may enhance expression of ribosomal genes by targeting nucleolus through Pns11.

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

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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.

Comprehensive phenotypic analysis of rice (Oryza sativa) response to salinity stress

KAUST Repository

Pires, Inês S.

2015-07-22

Increase in soil salinity levels is becoming a major cause of crop yield losses worldwide. Rice (Oryza sativa) is the most salt-sensitive cereal crop, and many studies have focused on rice salinity tolerance, but a global understanding of this crop\\'s response to salinity is still lacking. We systematically analyzed phenotypic data previously collected for 56 rice genotypes to assess the extent to which rice uses three known salinity tolerance mechanisms: shoot-ion independent tolerance (or osmotic tolerance), ion exclusion, and tissue tolerance. In general, our analyses of different phenotypic traits agree with results of previous rice salinity tolerance studies. However, we also established that the three salinity tolerance mechanisms mentioned earlier appear among rice genotypes and that none of them is predominant. Against the pervasive view in the literature that the K+/Na+ ratio is the most important trait in salinity tolerance, we found that the K+ concentration was not significantly affected by salt stress in rice, which puts in question the importance of K+/Na+ when analyzing rice salt stress response. Not only do our results contribute to improve our global understanding of salt stress response in an important crop, but we also use our results together with an extensive literature research to highlight some issues commonly observed in salinity stress tolerance studies and to propose solutions for future experiments.

Phloem-exudate proteome analysis of response to insect brown plant-hopper in rice.

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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.

Uncooked rice of relatively low gelatinization degree resulted in lower metabolic glucose and insulin responses compared with cooked rice in female college students.

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Jung, Eun Young; Suh, Hyung Joo; Hong, Wan Soo; Kim, Dong Geon; Hong, Yang Hee; Hong, In Sun; Chang, Un Jae

2009-07-01

Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses.

Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

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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.

Comprehensive phenotypic analysis of rice (Oryza sativa) response to salinity stress

KAUST Repository

Pires, Inê s S.; Negrã o, Só nia; Oliveira, M. Margarida; Purugganan, Michael D.

2015-01-01

affected by salt stress in rice, which puts in question the importance of K+/Na+ when analyzing rice salt stress response. Not only do our results contribute to improve our global understanding of salt stress response in an important crop, but we also use

Extracellular Alkalinization as a Defense Response in Potato Cells.

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Moroz, Natalia; Fritch, Karen R; Marcec, Matthew J; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

2017-01-01

A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists ( Phytophthora infestans and Spongospora subterranea ) and fungi ( Verticillium dahliae and Colletotrichum coccodes ). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes.

Jasmonic Acid, Abscisic Acid, and Salicylic Acid Are Involved in the Phytoalexin Responses of Rice to Fusarium fujikuroi, a High Gibberellin Producer Pathogen.

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Siciliano, Ilenia; Amaral Carneiro, Greice; Spadaro, Davide; Garibaldi, Angelo; Gullino, Maria Lodovica

2015-09-23

Fusarium fujikuroi, the causal agent of bakanae disease, is the main seedborne pathogen on rice. To understand the basis of rice resistance, a quantitative method to simultaneously detect phytohormones and phytoalexins was developed by using HPLC-MS/MS. With this method dynamic profiles and possible interactions of defense-related phytohormones and phytoalexins were investigated on two rice cultivars, inoculated or not with F. fujikuroi. In the resistant cultivar Selenio, the presence of pathogen induced high production of phytoalexins, mainly sakuranetin, and symptoms of bakanae were not observed. On the contrary, in the susceptible genotype Dorella, the pathogen induced the production of gibberellin and abscisic acid and inhibited jasmonic acid production, phytoalexins were very low, and bakanae symptoms were observed. The results suggested that a wide range of secondary metabolites are involved in plant defense against pathogens and phytoalexin synthesis could be an important factor for rice resistance against bakanae disease.

The contrasting responses of soil microorganisms in two rice cultivars to elevated ground-level ozone

International Nuclear Information System (INIS)

Feng, Youzhi; Yu, Yongjie; Tang, Haoye; Zu, Qianhui; Zhu, Jianguo; Lin, Xiangui

2015-01-01

Although elevated ground-level O 3 has a species–specific impact on plant growth, the differences in soil biota responses to O 3 pollution among rice cultivars are rarely reported. Using O 3 Free-Air Concentration Enrichment, the responses of the rhizospheric bacterial communities in the O 3 -tolerant (YD6) and the O 3 -sensitive (IIY084) rice cultivars to O 3 pollution and their differences were assessed by pyrosequencing at rice tillering and anthesis stages. Elevated ground-level O 3 negatively influenced the bacterial community in cultivar YD6 at both rice growth stages by decreasing the bacterial phylogenetic diversities and response ratios. In contrast, in cultivar IIY084, the bacterial community responded positively at the rice tillering stage under O 3 pollution. However, several keystone bacterial guilds were consistently negatively affected by O 3 pollution in two rice cultivars. These findings indicate that continuously O 3 pollution would negatively influence rice agroecosystem and the crop cultivar is important in determining the soil biota responses to elevated O 3 . - Highlights: • We investigated the soil biota in two rice cultivars in presence of elevated O 3 . • The contrasting responses of soil biota were found between two rice cultivars. • Some keystone bacterial guilds were consistently negatively affected by O 3 pollution. • The crop cultivar is important in determining soil biota responses to elevated O 3 . - The crop cultivar is important in determining the soil biota responses to elevated O 3

The Rice Mitochondria Proteome and its Response During Development and to the Environment

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Shaobai eHuang

2013-02-01

Full Text Available Rice (Oryza sativa L. is both a major crop species and the key model grass for molecular and physiological research. Mitochondria are important in rice, as in all crops, as the main source of ATP for cell maintenance and growth. However, the practical significance of understanding the function of mitochondria in rice is increased by the widespread farming practice of using hybrids to boost rice production. This relies on cytoplasmic male-sterile (CMS lines with abortive pollen caused by dysfunctional mitochondria. We provide an overview of what is known about the mitochondrial proteome of rice seedlings. To date, more than 320 proteins have been identified in purified rice mitochondria using mass spectrometry. The insights from this work include a broad understanding of the major subunits of mitochondrial respiratory complexes and TCA cycle enzymes, carbon and nitrogen metabolism enzymes as well as details of the supporting machinery for biogenesis and the subset of stress-responsive mitochondrial proteins. Many proteins with unknown functions have also been found in rice mitochondria. Proteomic analysis has also revealed the features of rice mitochondrial protein presequences required for mitochondrial targeting, as well as cleavage site features for processing of precursors after import. Changes in the abundance of rice mitochondrial proteins in response to different stresses, especially anoxia and light, are summarized. Future research on quantitative analysis of the rice mitochondrial proteomes at the spatial and developmental level, its response to environmental stresses and recent advances in understanding of basis of rice CMS systems are highlighted.

The DELLA Protein SLR1 Integrates and Amplifies Salicylic Acid- and Jasmonic Acid-Dependent Innate Immunity in Rice1

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De Vleesschauwer, David; Seifi, Hamed Soren; Haeck, Ashley; Huu, Son Nguyen; Demeestere, Kristof

2016-01-01

Gibberellins are a class of tetracyclic plant hormones that are well known to promote plant growth by inducing the degradation of a class of nuclear growth-repressing proteins, called DELLAs. In recent years, GA and DELLAs are also increasingly implicated in plant responses to pathogen attack, although our understanding of the underlying mechanisms is still limited, especially in monocotyledonous crop plants. Aiming to further decipher the molecular underpinnings of GA- and DELLA-modulated plant immunity, we studied the dynamics and impact of GA and DELLA during infection of the model crop rice (Oryza sativa) with four different pathogens exhibiting distinct lifestyles and infection strategies. Opposite to previous findings in Arabidopsis (Arabidopsis thaliana), our findings reveal a prominent role of the DELLA protein Slender Rice1 (SLR1) in the resistance toward (hemi)biotrophic but not necrotrophic rice pathogens. Moreover, contrary to the differential effect of DELLA on the archetypal defense hormones salicylic acid (SA) and jasmonic acid (JA) in Arabidopsis, we demonstrate that the resistance-promoting effect of SLR1 is due at least in part to its ability to boost both SA- and JA-mediated rice defenses. In a reciprocal manner, we found JA and SA treatment to interfere with GA metabolism and stabilize SLR1. Together, these findings favor a model whereby SLR1 acts as a positive regulator of hemibiotroph resistance in rice by integrating and amplifying SA- and JA-dependent defense signaling. Our results highlight the differences in hormone defense networking between rice and Arabidopsis and underscore the importance of GA and DELLA in molding disease outcomes. PMID:26829979

The DELLA Protein SLR1 Integrates and Amplifies Salicylic Acid- and Jasmonic Acid-Dependent Innate Immunity in Rice.

Science.gov (United States)

De Vleesschauwer, David; Seifi, Hamed Soren; Filipe, Osvaldo; Haeck, Ashley; Huu, Son Nguyen; Demeestere, Kristof; Höfte, Monica

2016-03-01

Gibberellins are a class of tetracyclic plant hormones that are well known to promote plant growth by inducing the degradation of a class of nuclear growth-repressing proteins, called DELLAs. In recent years, GA and DELLAs are also increasingly implicated in plant responses to pathogen attack, although our understanding of the underlying mechanisms is still limited, especially in monocotyledonous crop plants. Aiming to further decipher the molecular underpinnings of GA- and DELLA-modulated plant immunity, we studied the dynamics and impact of GA and DELLA during infection of the model crop rice (Oryza sativa) with four different pathogens exhibiting distinct lifestyles and infection strategies. Opposite to previous findings in Arabidopsis (Arabidopsis thaliana), our findings reveal a prominent role of the DELLA protein Slender Rice1 (SLR1) in the resistance toward (hemi)biotrophic but not necrotrophic rice pathogens. Moreover, contrary to the differential effect of DELLA on the archetypal defense hormones salicylic acid (SA) and jasmonic acid (JA) in Arabidopsis, we demonstrate that the resistance-promoting effect of SLR1 is due at least in part to its ability to boost both SA- and JA-mediated rice defenses. In a reciprocal manner, we found JA and SA treatment to interfere with GA metabolism and stabilize SLR1. Together, these findings favor a model whereby SLR1 acts as a positive regulator of hemibiotroph resistance in rice by integrating and amplifying SA- and JA-dependent defense signaling. Our results highlight the differences in hormone defense networking between rice and Arabidopsis and underscore the importance of GA and DELLA in molding disease outcomes. © 2016 American Society of Plant Biologists. All Rights Reserved.

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

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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 .

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.

Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

OpenAIRE

Simon Swapna; Korukkanvilakath Samban Shylaraj

2017-01-01

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...

MARKET SUPPLY RESPONSE AND DEMAND FOR LOCAL RICE IN NIGERIA: IMPLICATIONS FOR SELF-SUFFICIENCY POLICY

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M RAHJI

2009-03-01

Full Text Available This study examined the supply response and demand for local rice in Nigeria between 1960 and 2004. A system of equations using secondary data was estimated by OLS and 2SLS techniques. Area planted with local rice is mainly affected by expected price of output, agriculture wage rate and by the partial adjustment coefficient. The short-run response elasticity is 0.077. The implied long-run response elasticity is 1.578. The partial adjustment measure is 0.049. This, points to the difficulty of supply response to changing economic conditions. The price elasticity of demand obtained is 0.841. The demand for local rice is thus price inelastic. Rice income elasticity is 0.3378. It is also inelastic. The ban on rice importation in Nigeria could be said to be a step in the right direction. This policy should be continued and policed. However, price, output and non-price incentives that can exert significant influence on rice supply response and demand are required if the self-sufficiency goal is to be achieved.

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

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Xiao-chan HE

2012-12-01

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

Brassinosteroids antagonize gibberellin- and salicylate-mediated root immunity in rice.

Science.gov (United States)

De Vleesschauwer, David; Van Buyten, Evelien; Satoh, Kouji; Balidion, Johny; Mauleon, Ramil; Choi, Il-Ryong; Vera-Cruz, Casiana; Kikuchi, Shoshi; Höfte, Monica

2012-04-01

Brassinosteroids (BRs) are a unique class of plant steroid hormones that orchestrate myriad growth and developmental processes. Although BRs have long been known to protect plants from a suite of biotic and abiotic stresses, our understanding of the underlying molecular mechanisms is still rudimentary. Aiming to further decipher the molecular logic of BR-modulated immunity, we have examined the dynamics and impact of BRs during infection of rice (Oryza sativa) with the root oomycete Pythium graminicola. Challenging the prevailing view that BRs positively regulate plant innate immunity, we show that P. graminicola exploits BRs as virulence factors and hijacks the rice BR machinery to inflict disease. Moreover, we demonstrate that this immune-suppressive effect of BRs is due, at least in part, to negative cross talk with salicylic acid (SA) and gibberellic acid (GA) pathways. BR-mediated suppression of SA defenses occurred downstream of SA biosynthesis, but upstream of the master defense regulators NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and OsWRKY45. In contrast, BR alleviated GA-directed immune responses by interfering at multiple levels with GA metabolism, resulting in indirect stabilization of the DELLA protein and central GA repressor SLENDER RICE1 (SLR1). Collectively, these data favor a model whereby P. graminicola coopts the plant BR pathway as a decoy to antagonize effectual SA- and GA-mediated defenses. Our results highlight the importance of BRs in modulating plant immunity and uncover pathogen-mediated manipulation of plant steroid homeostasis as a core virulence strategy.

Peptidoglycan from Fermentation By-Product Triggers Defense Responses in Grapevine

Science.gov (United States)

Chen, Yang; Takeda, Taito; Aoki, Yoshinao; Fujita, Keiko; Suzuki, Shunji; Igarashi, Daisuke

2014-01-01

Plants are constantly under attack from a variety of microorganisms, and rely on a series of complex detection and response systems to protect themselves from infection. Here, we found that a by-product of glutamate fermentation triggered defense responses in grapevine, increasing the expression of defense response genes in cultured cells, foliar chitinase activity, and resistance to infection by downy mildew in leaf explants. To identify the molecule that triggered this innate immunity, we fractionated and purified candidates extracted from Corynebacterium glutamicum, a bacterium used in the production of amino acids by fermentation. Using hydrolysis by lysozyme, a silkworm larva plasma detection system, and gel filtration analysis, we identified peptidoglycan as inducing the defense responses. Peptidoglycans of Escherichia coli, Bacillus subtilis, and Staphylococcus aureus also generated similar defensive responses. PMID:25427192

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

Effector Mimics and Integrated Decoys, the Never-Ending Arms Race between Rice and Xanthomonas oryzae

OpenAIRE

Zuluaga, Paola; Szurek, Boris; Koebnik, Ralf; Kroj, Thomas; Morel, Jean-Benoit

2017-01-01

Plants are constantly challenged by a wide range of pathogens and have therefore evolved an array of mechanisms to defend against them. In response to these defense systems, pathogens have evolved strategies to avoid recognition and suppress plant defenses (Brown and Tellier, 2011). Three recent reports dealing with the resistance of rice to Xanthomonas oryzae have added a new twist to our understanding of this fascinating co-evolutionary arms race (Ji et al., 2016; Read et al., 2016; Triplet...

QTL analysis of internode elongation in response to gibberellin in deepwater rice

OpenAIRE

Nagai, Keisuke; Kondo, Yuma; Kitaoka, Takuya; Noda, Tomonori; Kuroha, Takeshi; Angeles-Shim, Rosalyn B.; Yasui, Hideshi; Yoshimura, Atsushi; Ashikari, Motoyuki

2014-01-01

Gibberellin (GA) is a plant hormone that has important roles in numerous plant developmental phases. Rice plants known as deepwater rice respond to flooding by elongating their internodes to avoid anoxia. Previous studies reported that GA is essential for internode elongation in deepwater rice. Quantitative trait locus (QTL) analyses identified QTLs regulating internode elongation in response to deepwater conditions. However, the interaction between internode elongation and regulators of GA s...

Intraspecific responses of 188 rice cultivars to enhanced UVB radiation

International Nuclear Information System (INIS)

Dai, Q.; Peng, A.; Chavez, A.Q.; Vergara, B.S.

1994-01-01

Phytotron studies were conducted to determine the intraspecific variation in sensitivity of rice (Oryza sativa L.) to enhanced UVB and to test the hypothesis that rice cultivars originating from regions with higher ambient UVB radiation are more tolerant to enhanced UVB. Out of the 188 rice cultivars (from various rice growing regions and ecosystems) tested, 143 had significantly reduced plant height, 52 had smaller leaf area, 61 had lower plant dry weight and 41 had less tiller number under elevated UVB radiation (13.0 kJ m −2 day −1 ) for 3 weeks. Six cultivars showed significant positive growth response to enhanced UVB radiation, although the mechanism is not clear at present. These six cultivars were from the summer rice crop of Bangladesh and from high elevation rice areas where prevailing UVB radiation is most likely to be greater. However, there was no correlation between the dry matter changes under enhanced UVB and the ambient UVB level at the origin of the cultivar across the 188 cultivars tested. Therefore, cultivars originating from regions with higher ambient UVB are not necessarily more tolerant to enhanced UVB radiation. (author)

A salivary EF-hand calcium-binding protein of the brown planthopper Nilaparvata lugens functions as an effector for defense responses in rice

OpenAIRE

Ye, Wenfeng; Yu, Haixin; Jian, Yukun; Zeng, Jiamei; Ji, Rui; Chen, Hongdan; Lou, Yonggen

2017-01-01

The brown planthopper (BPH), Nilaparvata lugens (St?l) (Hemiptera: Delphacidae), a major pest of rice in Asia, is able to successfully puncture sieve tubes in rice with its piercing stylet and then to ingest phloem sap. How BPH manages to continuously feed on rice remains unclear. Here, we cloned the gene NlSEF1, which is highly expressed in the salivary glands of BPH. The NlSEF1 protein has EF-hand Ca2+-binding activity and can be secreted into rice plants when BPH feed. Infestation of rice ...

UV-B effects on crops: response of the irrigated rice ecosystem

International Nuclear Information System (INIS)

Olszyk, D.; Dai, Q.; Teng, P.; Leung, H.; Luo, Y.; Peng, S.

1996-01-01

Increasing ultraviolet-B (UV-B) radiation resulting from depletion of the stratospheric ozone layer could have damaging effects on crops. This paper reviews recent findings on direct effects of UV-B on rice growth and yield as well as indirect effects via impacts on other organisms in the rice (Oryza sativa) agroecosystem. The findings are based on research by scientists at the International Rice Research Institute (IRRI) in Los Baños, the Philippines, and their collaborators in China and the United States; with comparison to research by scientists in other countries. Current results indicate that while enhanced UV-B directly impacts many aspects of rice growth, physiology, and biochemistry under controlled phytotron conditions; in general rice growth and yield are not affected under natural field conditions. The difference in response may be related both to the levels of UV-B exposure used in phytotron vs. field studies and the lower ratio of UV-A to UV-B in the phytotron compared to field. In terms of indirect effects on rice blast disease, enhanced UV-B affected both the fungus itself (Pyricularia grisea) and the susceptibility of the rice plant to the fungus. Based on these data, simulation models estimated potential impacts of higher UV-B levels on blast severity and rice yield in different countries of southeast and east Asia. Ultimately, results from rice studies can be used to identify strategies to minimize any negative effects of UV-B on rice productivity

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.

Adjuvant activity of peanut, cottonseed and rice oils on cellular and humoral response

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Erika Freitas

2013-04-01

Full Text Available The potentiality of the usage of vegetable oils such as soybean, corn, olive, sesame, murici seed, rapeseed, linseed, rice and cashew nuts as adjuvant of the humoral and cellular immune response has been recently shown. In the present work, besides of evaluating the adjuvant action of peanut, cottonseed and rice oils on humoral and cellular immune responses against ovalbumin (OVA we also evaluated the protective immune response induced by Leishmania antigens. The peanut oil significantly increased the synthesis of anti-ovalbumin antibodies in the primary response, but it did not favor cellular response. Concerning mice immunized with L. amazonensis antigens emulsified with peanut oil exacerbated skin lesions and lymph node parasite load what suggests stimulation of the Th2 immune response and down regulation of Th1 response. The cottonseed oil was shown to have adjuvant effect to the humoral response, stimulating a secondary response and also favored the delayed-type hypersensitivity (DTH response to OVA. The rice oil stimulated a strong DTH reaction to OVA and enhanced the synthesis of antibodies after the third dose. Mice immunized with L. amazonensis antigens emulsified with rice oil or cotton seed oil were protected from developing skin lesions and lymph node parasite load. These results emphasize the interest and importance of the vegetable oils as tools in different procedures of immunization and their differential role in relation to the other adjuvant under usage.

Analysis of five rice 4-coumarate:coenzyme A ligase enzyme activity and stress response for potential roles in lignin and flavonoid biosynthesis in rice

International Nuclear Information System (INIS)

Sun, Haiyan; Li, Ying; Feng, Shengqiu; Zou, Weihua; Guo, Kai; Fan, Chunfen; Si, Shengli

2013-01-01

Highlights: ► 4CLs play important roles in both lignin and flavonoids biosynthesis. ► PA and FA are the two main substrates of 4CL (Os4CL1/3/4/5) for lignin biosynthesis. ► Os4CL2 is suggested for flavonoid formation in defense against UV radiation. -- Abstract: 4-Coumarate:coenzyme A ligase (4CL) catalyzes the conversion of hydroxycinnamates into corresponding CoA esters for biosynthesis of flavonoids and lignin. In this study, five members of the 4CL gene family from rice were cloned and analyzed. Recombinant 4CL data revealed that 4-coumaric acid and ferulic acid were the two main substrates of 4CL (Os4CL1/3/4/5) for monolignol biosynthesis in rice. Os4CL2 was specifically expressed in the anther and was strongly activated by UV irradiation, suggesting its potential involvement in flavonoid formation. Moreover, bioinformatics analysis showed that the existence of valine residue at the substrate-binding pocket may mainly affect rice 4CL activities toward sinapic acid

Analysis of five rice 4-coumarate:coenzyme A ligase enzyme activity and stress response for potential roles in lignin and flavonoid biosynthesis in rice

Energy Technology Data Exchange (ETDEWEB)

Sun, Haiyan [National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070 (China); Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); School of Biology and Food Engineering, Changshu Institute of Technology, Changshu 215500 (China); Li, Ying; Feng, Shengqiu; Zou, Weihua [National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070 (China); Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Guo, Kai [National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070 (China); Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Fan, Chunfen [National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070 (China); Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Si, Shengli [National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070 (China); Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); and others

2013-01-18

Highlights: ► 4CLs play important roles in both lignin and flavonoids biosynthesis. ► PA and FA are the two main substrates of 4CL (Os4CL1/3/4/5) for lignin biosynthesis. ► Os4CL2 is suggested for flavonoid formation in defense against UV radiation. -- Abstract: 4-Coumarate:coenzyme A ligase (4CL) catalyzes the conversion of hydroxycinnamates into corresponding CoA esters for biosynthesis of flavonoids and lignin. In this study, five members of the 4CL gene family from rice were cloned and analyzed. Recombinant 4CL data revealed that 4-coumaric acid and ferulic acid were the two main substrates of 4CL (Os4CL1/3/4/5) for monolignol biosynthesis in rice. Os4CL2 was specifically expressed in the anther and was strongly activated by UV irradiation, suggesting its potential involvement in flavonoid formation. Moreover, bioinformatics analysis showed that the existence of valine residue at the substrate-binding pocket may mainly affect rice 4CL activities toward sinapic acid.

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

Distinct roles of jasmonates and aldehydes in plant-defense responses.

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E Wassim Chehab

Full Text Available BACKGROUND: Many inducible plant-defense responses are activated by jasmonates (JAs, C(6-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS and hydroperoxide lyase (HPL branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C(6-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C(6-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae, an insect herbivore (leafminers: Liriomyza trifolii, and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola. We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani, a natural enemy of aphids. PRINCIPAL FINDINGS: This study conclusively establishes that jasmonates and C(6-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C(6-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C(6-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic

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...

Limited response of ponderosa pine bole defenses to wounding and fungi.

Science.gov (United States)

Gaylord, Monica L; Hofstetter, Richard W; Kolb, Thomas E; Wagner, Michael R

2011-04-01

Tree defense against bark beetles (Curculionidae: Scolytinae) and their associated fungi generally comprises some combination of constitutive (primary) and induced (secondary) defenses. In pines, the primary constitutive defense against bark beetles consists of preformed resin stored in resin ducts. Induced defenses at the wound site (point of beetle entry) in pines may consist of an increase in resin flow and necrotic lesion formation. The quantity and quality of both induced and constitutive defenses can vary by species and season. The inducible defense response in ponderosa pine is not well understood. Our study examined the inducible defense response in ponderosa pine using traumatic mechanical wounding, and wounding with and without fungal inoculations with two different bark beetle-associated fungi (Ophiostoma minus and Grosmannia clavigera). Resin flow did not significantly increase in response to any treatment. In addition, necrotic lesion formation on the bole after fungal inoculation was minimal. Stand thinning, which has been shown to increase water availability, had no, or inconsistent, effects on inducible tree defense. Our results suggest that ponderosa pine bole defense against bark beetles and their associated fungi is primarily constitutive and not induced.

A model for photothermal responses of flowering in rice. II. Model evaluation.

NARCIS (Netherlands)

Yin, X.; Kropff, M.J.; Nakagawa, H.; Horie, T.; Goudriaan, J.

1997-01-01

A detailed nonlinear model, the 3s-Beta model, for photothermal responses of flowering in rice (Oryza sativa L.) was evaluated for predicting rice flowering date in field conditions. This model was compared with other three models: a three-plane linear model and two nonlinear models, viz, the

Herbicidal and antioxidant responses of transgenic rice overexpressing Myxococcus xanthus protoporphyrinogen oxidase.

Science.gov (United States)

Jung, Sunyo; Back, Kyoungwhan

2005-05-01

We analyzed the herbicidal and antioxidant defense responses of transgenic rice plants that overexpressed the Myxococcus xanthus protoporphyrinogen oxidase gene. Leaf squares of the wild-type incubated with oxyfluorfen were characterized by necrotic leaf lesions and increases in conductivity and malonyldialdehyde levels, whereas transgenic lines M4 and M7 did not show any change with up to 100 microM oxyfluorfen. The wild-type had decreased F(v)/F(m) and produced a high level of H(2)O(2) at 18 h after foliar application of oxyfluorfen, whereas transgenic lines M4 and M7 were unaffected. In response to oxyfluorfen, violaxanthin, beta-carotene, and chlorophylls (Chls) decreased in wild-type plants, whereas antheraxanthin and zeaxanthin increased. Only a slight decline in Chls was observed in transgenic lines at 48 h after oxyfluorfen treatment. Noticeable increases of cytosolic Cu/Zn-superoxide dismutase, peroxidase isozymes 1 and 2, and catalase were observed after at 48 h of oxyfluorfen treatment in the wild-type. Non-enzymatic antioxidants appeared to respond faster to oxyfluorfen-induced photodynamic stress than did enzymatic antioxidants. Protective responses for the detoxification of active oxygen species were induced to counteract photodynamic stress in oxyfluorfen-treated, wild-type plants. However, oxyfluorfen-treated, transgenic plants suffered less oxidative stress, confirming increased herbicidal resistance resulted from dual expression of M. xanthus Protox in chloroplasts and mitochondria.

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)

A Genetic Screen Identifies a Requirement for Cysteine-Rich-Receptor-Like Kinases in Rice NH1 (OsNPR1-Mediated Immunity.

Directory of Open Access Journals (Sweden)

Mawsheng Chern

2016-05-01

Full Text Available Systemic acquired resistance, mediated by the Arabidopsis NPR1 gene and the rice NH1 gene, confers broad-spectrum immunity to diverse pathogens. NPR1 and NH1 interact with TGA transcription factors to activate downstream defense genes. Despite the importance of this defense response, the signaling components downstream of NPR1/NH1 and TGA proteins are poorly defined. Here we report the identification of a rice mutant, snim1, which suppresses NH1-mediated immunity and demonstrate that two genes encoding previously uncharacterized cysteine-rich-receptor-like kinases (CRK6 and CRK10, complement the snim1 mutant phenotype. Silencing of CRK6 and CRK10 genes individually in the parental genetic background recreates the snim1 phenotype. We identified a rice mutant in the Kitaake genetic background with a frameshift mutation in crk10; this mutant also displays a compromised immune response highlighting the important role of crk10. We also show that elevated levels of NH1 expression lead to enhanced CRK10 expression and that the rice TGA2.1 protein binds to the CRK10 promoter. These experiments demonstrate a requirement for CRKs in NH1-mediated immunity and establish a molecular link between NH1 and induction of CRK10 expression.

Capsicum annuum WRKY transcription factor d (CaWRKYd) regulates hypersensitive response and defense response upon Tobacco mosaic virus infection.

Science.gov (United States)

Huh, Sung Un; Choi, La Mee; Lee, Gil-Je; Kim, Young Jin; Paek, Kyung-Hee

2012-12-01

WRKY transcription factors regulate biotic, abiotic, and developmental processes. In terms of plant defense, WRKY factors have important roles as positive and negative regulators via transcriptional regulation or protein-protein interaction. Here, we report the characterization of the gene encoding Capsicum annuum WRKY transcription factor d (CaWRKYd) isolated from microarray analysis in the Tobacco mosaic virus (TMV)-P(0)-inoculated hot pepper plants. CaWRKYd belongs to the WRKY IIa group, a very small clade in the WRKY subfamily, and WRKY IIa group has positive/negative regulatory roles in Arabidopsis and rice. CaWRKYd transcripts were induced by various plant defense-related hormone treatments and TMV-P(0) inoculation. Silencing of CaWRKYd affected TMV-P(0)-mediated hypersensitive response (HR) cell death and accumulation of TMV-P(0) coat protein in local and systemic leaves. Furthermore, expression of some pathogenesis-related (PR) genes and HR-related genes was reduced in the CaWRKYd-silenced plants compared with TRV2 vector control plants upon TMV-P(0) inoculation. CaWRKYd was confirmed to bind to the W-box. Thus CaWRKYd is a newly identified Capsicum annuum WRKY transcription factor that appears to be involved in TMV-P(0)-mediated HR cell death by regulating downstream gene expression. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Rice rhizosphere soil and root surface bacterial community response to water management changes

Science.gov (United States)

Different water management practices could affect microbial populations in the rice rhizosphere. A field-scale study was conducted to evaluate microbial populations in the root plaque and rhizosphere of rice in response to continuous and intermittent flooding conditions. Microbial populations in rhi...

Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

Directory of Open Access Journals (Sweden)

Wijaya Edward

2010-01-01

Full Text Available Abstract Background The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10°C, an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach. Results Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10°C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters. Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2 spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters. Conclusion Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries.

Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

KAUST Repository

Yun, Kil-Young

2010-01-25

Background: The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10C), an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach.Results: Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters.Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters.Conclusion: Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries. 2010 Yun et al; licensee BioMed Central Ltd.

Radiobiological response of fast neutrons on seedling growth of rice varieties with different amylose content

International Nuclear Information System (INIS)

Baradjanegara, A.A.; Sugiyanto, T.; Rahayu, S.

1978-01-01

Many studies are reported on radiation effects and on factors modifying the biological response of radiation in rice. However, little attention was directed towards studying effects of fast neutrons on seedling growth response of rice as a function of chemical constituents (e.g. amylose content). Experiments were conducted to investigate the dependency of amylose content in 4 rice cultivars on radiosensitivity to fast neutrons. From the results obtained a clear relationship between amylose content and sensitivity to fast neutrons could be shown. (author)

Effector Mimics and Integrated Decoys, the Never-Ending Arms Race between Rice and Xanthomonas oryzae.

Science.gov (United States)

Zuluaga, Paola; Szurek, Boris; Koebnik, Ralf; Kroj, Thomas; Morel, Jean-Benoit

2017-01-01

Plants are constantly challenged by a wide range of pathogens and have therefore evolved an array of mechanisms to defend against them. In response to these defense systems, pathogens have evolved strategies to avoid recognition and suppress plant defenses (Brown and Tellier, 2011). Three recent reports dealing with the resistance of rice to Xanthomonas oryzae have added a new twist to our understanding of this fascinating co-evolutionary arms race (Ji et al., 2016; Read et al., 2016; Triplett et al., 2016). They show that pathogens also develop sophisticated effector mimics to trick recognition.

ANALYSIS OF SUPPLY RESPONSE AND PRICE RISK ON RICE PRODUCTION IN NIGERIA

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Opeyemi Eyitayo Ayinde

2017-03-01

Full Text Available  Nigeria, like most African countries, has engaged in agricultural liberalization since 1986 in the hope that reforms emphasizing price incentives will encourage producers to respond. Thus far, the reforms seem to have introduced greater uncertainty into the market given increasing rates of price volatility. This study amongst other things therefore seeks to determine and model the responsiveness of rice supply to price risk in Nigeria. Statistical information on domestic and imported quantities of rice was obtained for 41 years (1970 to 2011 from various sources, such as the Food and Agriculture Organization (FAO database, Federal Ministry of Agriculture statistical bulletins, Central Bank of Nigeria statistical bulletins and National Bureau of Statistic (NBS. Data were analyzed using equilibrium output supply function, co-integration models, and vector autoregressive distributed lag model. Rice importation was statistically significant and changes in output were also responsive to changes in price. The results indicate that producers are more responsive not only to price and non-price factor but also to price risk and exchange rate. It is therefore imperative to reduce the effects of price risk as to increase the response of producer to supply by bridging the gap in production

Responses of sri lankan traditional rice to photoperiod at early vegetative stage

International Nuclear Information System (INIS)

Rathnathunga, U.U.E.; Geekiyanage, S.

2017-01-01

Rice is a photoperiod sensitive plant for flowering initiation. Effect of photoperiod can be important in vegetative growth and yield determination in rice. The objective of the research was to determine the effect of photoperiod on the vegetative responses of Sri Lankan traditional rice germplasm (SLTRG). Forty five traditional rice accessions (TRA), 5 improved rice varieties (IR), Sri Lankan wild rice (Oryza nivara and Oryza rufipogan) and Oryza japonica accessions 6782 and 6752 were grown in short day (SD), day neutral (DN) and long day (LD) conditions. Days to reach the fifth leaf stage (DFL), plant height (PH) and tiller number (TN) at the fifth leaf stage were recorded. Twenty three genotypes including 21 TRA, Oryza japonica 6752 and Oryza nivara did not respond to photoperiod having non-significant values for DFL, PH and TN among photoperiods. The DFL was affected in 25 genotypes; among them both DFL and PH were affected in 7 genotypes. DFL was significantly increased during LD in 4 TRA while DFL was significantly reduced in all 5 IR and 5 TRA. DFL was significantly increased in Oryza japonica 6782 and 5 TRA under SD. In 4 TRA, DFL was reduced under SD. The TN was affected in Oryza japonica 6782 only under SD with increased DFL. The DFL was significantly increased under DN in Oryza rufipogan, 5 TRA and 2 IR. Both SD and LD photoperiods differently affected the interaction between DFL and PH in TRA while only LD affected that of IR. DN had an effect on the interaction between DFL and PH only in wild rice Oryza rufipogon. Variation of vegetative growth response to photoperiod may depict the wide genetic basis of SLTRG. (author)

Transcriptomic analysis of rice aleurone cells identified a novel abscisic acid response element.

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Watanabe, Kenneth A; Homayouni, Arielle; Gu, Lingkun; Huang, Kuan-Ying; Ho, Tuan-Hua David; Shen, Qingxi J

2017-09-01

Seeds serve as a great model to study plant responses to drought stress, which is largely mediated by abscisic acid (ABA). The ABA responsive element (ABRE) is a key cis-regulatory element in ABA signalling. However, its consensus sequence (ACGTG(G/T)C) is present in the promoters of only about 40% of ABA-induced genes in rice aleurone cells, suggesting other ABREs may exist. To identify novel ABREs, RNA sequencing was performed on aleurone cells of rice seeds treated with 20 μM ABA. Gibbs sampling was used to identify enriched elements, and particle bombardment-mediated transient expression studies were performed to verify the function. Gene ontology analysis was performed to predict the roles of genes containing the novel ABREs. This study revealed 2443 ABA-inducible genes and a novel ABRE, designated as ABREN, which was experimentally verified to mediate ABA signalling in rice aleurone cells. Many of the ABREN-containing genes are predicted to be involved in stress responses and transcription. Analysis of other species suggests that the ABREN may be monocot specific. This study also revealed interesting expression patterns of genes involved in ABA metabolism and signalling. Collectively, this study advanced our understanding of diverse cis-regulatory sequences and the transcriptomes underlying ABA responses in rice aleurone cells. © 2017 John Wiley & Sons Ltd.

A Hypersensitivity-Like Response to Meloidogyne graminicola in Rice (Oryza sativa).

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Phan, Ngan Thi; De Waele, Dirk; Lorieux, Mathias; Xiong, Lizhong; Bellafiore, Stephane

2018-04-01

Meloidogyne graminicola is a major plant-parasitic nematode affecting rice cultivation in Asia. Resistance to this nematode was found in the African rice genotypes Oryza glaberrima and O. longistaminata; however, due to interspecific hybrid sterility, the introgression of resistance genes in the widely consumed O. sativa varieties remains challenging. Recently, resistance was found in O. sativa and, here, we report for the first time the histological and genetic characterization of the resistance to M. graminicola in Zhonghua 11, an O. sativa variety. Bright-light microscopy and fluorescence observations of the root tissue of this variety revealed that the root cells surrounding the nematode displayed a hypersensitivity-like reaction with necrotic cells at early stages of infection when nematodes are migrating in the root's mesoderm. An accumulation of presumably phenolic compounds in the nematodes' neighboring root cells was also observed. In addition, at a later stage of infection, not only were few feeding sites observed but also the giant cells were underdeveloped, underlining an incompatible interaction. Furthermore, we generated a hybrid O. sativa population by crossing Zhonghua 11 with the susceptible O. sativa variety IR64 in order to describe the genetic background of this resistance. Our data suggested that the resistance to M. graminicola infection was qualitative rather than quantitative and, therefore, major resistance genes must be involved in this infection process. The full characterization of the defense mechanism and the preliminary study of the genetic inheritance of novel sources of resistance to Meloidogyne spp. in rice constitute a major step toward their use in crop breeding.

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.

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

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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.

Dose-dependent response of Trichoderma harzianum in improving drought tolerance in rice genotypes.

Science.gov (United States)

Pandey, Veena; Ansari, Mohammad W; Tula, Suresh; Yadav, Sandep; Sahoo, Ranjan K; Shukla, Nandini; Bains, Gurdeep; Badal, Shail; Chandra, Subhash; Gaur, A K; Kumar, Atul; Shukla, Alok; Kumar, J; Tuteja, Narendra

2016-05-01

This study demonstrates a dose-dependent response of Trichoderma harzianum Th-56 in improving drought tolerance in rice by modulating proline, SOD, lipid peroxidation product and DHN / AQU transcript level, and the growth attributes. In the present study, the effect of colonization of different doses of T. harzianum Th-56 strain in rice genotypes were evaluated under drought stress. The rice genotypes treated with increasing dose of T. harzianum strain Th-56 showed better drought tolerance as compared with untreated control plant. There was significant change in malondialdehyde, proline, higher superoxide dismutase level, plant height, total dry matter, relative chlorophyll content, leaf rolling, leaf tip burn, and the number of scorched/senesced leaves in T. harzianum Th-56 treated rice genotypes under drought stress. This was corroborated with altered expression of aquaporin and dehydrin genes in T. harzianum Th-56 treated rice genotypes. The present findings suggest that a dose of 30 g/L was the most effective in improving drought tolerance in rice, and its potential exploitation will contribute to the advancement of rice genotypes to sustain crop productivity under drought stress. Interaction studies of T. harzianum with three aromatic rice genotypes suggested that PSD-17 was highly benefitted from T. harzianum colonization under drought stress.

Comparative transcriptome analysis of two rice varieties in response to rice stripe virus and small brown planthoppers during early interaction.

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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.

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.

Crop response of aerobic rice and winter wheat to nitrogen, phosphorus and potassium in a double cropping system

NARCIS (Netherlands)

Dai, X.Q.; Zhang, H.Y.; Spiertz, J.H.J.; Yu, J.; Xie, G.H.; Bouman, B.A.M.

2010-01-01

In the aerobic rice system, adapted rice cultivars are grown in non-flooded moist soil. Aerobic rice may be suitable for double cropping with winter wheat in the Huai River Basin, northern China plain. Field experiments in 2005 and 2006 were conducted to study the response of aerobic rice and winter

Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.).

Science.gov (United States)

Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

2016-01-01

Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

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.

Improving Rice Modeling Success Rate with Ternary Non-structural Fertilizer Response Model.

Science.gov (United States)

Li, Juan; Zhang, Mingqing; Chen, Fang; Yao, Baoquan

2018-06-13

Fertilizer response modelling is an important technical approach to realize metrological fertilization on rice. With the goal of solving the problems of a low success rate of a ternary quadratic polynomial model (TPFM) and to expand the model's applicability, this paper established a ternary non-structural fertilizer response model (TNFM) based on the experimental results from N, P and K fertilized rice fields. Our research results showed that the TNFM significantly improved the modelling success rate by addressing problems arising from setting the bias and multicollinearity in a TPFM. The results from 88 rice field trials in China indicated that the proportion of typical TNFMs that satisfy the general fertilizer response law of plant nutrition was 40.9%, while the analogous proportion of TPFMs was only 26.1%. The recommended fertilization showed a significant positive linear correlation between the two models, and the parameters N 0 , P 0 and K 0 that estimated the value of soil supplying nutrient equivalents can be used as better indicators of yield potential in plots where no N or P or K fertilizer was applied. The theoretical analysis showed that the new model has a higher fitting accuracy and a wider application range.

Brassinosteroids Antagonize Gibberellin- and Salicylate-Mediated Root Immunity in Rice1[C][W][OA

Science.gov (United States)

De Vleesschauwer, David; Van Buyten, Evelien; Satoh, Kouji; Balidion, Johny; Mauleon, Ramil; Choi, Il-Ryong; Vera-Cruz, Casiana; Kikuchi, Shoshi; Höfte, Monica

2012-01-01

Brassinosteroids (BRs) are a unique class of plant steroid hormones that orchestrate myriad growth and developmental processes. Although BRs have long been known to protect plants from a suite of biotic and abiotic stresses, our understanding of the underlying molecular mechanisms is still rudimentary. Aiming to further decipher the molecular logic of BR-modulated immunity, we have examined the dynamics and impact of BRs during infection of rice (Oryza sativa) with the root oomycete Pythium graminicola. Challenging the prevailing view that BRs positively regulate plant innate immunity, we show that P. graminicola exploits BRs as virulence factors and hijacks the rice BR machinery to inflict disease. Moreover, we demonstrate that this immune-suppressive effect of BRs is due, at least in part, to negative cross talk with salicylic acid (SA) and gibberellic acid (GA) pathways. BR-mediated suppression of SA defenses occurred downstream of SA biosynthesis, but upstream of the master defense regulators NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and OsWRKY45. In contrast, BR alleviated GA-directed immune responses by interfering at multiple levels with GA metabolism, resulting in indirect stabilization of the DELLA protein and central GA repressor SLENDER RICE1 (SLR1). Collectively, these data favor a model whereby P. graminicola coopts the plant BR pathway as a decoy to antagonize effectual SA- and GA-mediated defenses. Our results highlight the importance of BRs in modulating plant immunity and uncover pathogen-mediated manipulation of plant steroid homeostasis as a core virulence strategy. PMID:22353574

Transcription Factor Functional Protein-Protein Interactions in Plant Defense Responses

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Murilo S. Alves

2014-03-01

Full Text Available Responses to biotic stress in plants lead to dramatic reprogramming of gene expression, favoring stress responses at the expense of normal cellular functions. Transcription factors are master regulators of gene expression at the transcriptional level, and controlling the activity of these factors alters the transcriptome of the plant, leading to metabolic and phenotypic changes in response to stress. The functional analysis of interactions between transcription factors and other proteins is very important for elucidating the role of these transcriptional regulators in different signaling cascades. In this review, we present an overview of protein-protein interactions for the six major families of transcription factors involved in plant defense: basic leucine zipper containing domain proteins (bZIP, amino-acid sequence WRKYGQK (WRKY, myelocytomatosis related proteins (MYC, myeloblastosis related proteins (MYB, APETALA2/ ETHYLENE-RESPONSIVE ELEMENT BINDING FACTORS (AP2/EREBP and no apical meristem (NAM, Arabidopsis transcription activation factor (ATAF, and cup-shaped cotyledon (CUC (NAC. We describe the interaction partners of these transcription factors as molecular responses during pathogen attack and the key components of signal transduction pathways that take place during plant defense responses. These interactions determine the activation or repression of response pathways and are crucial to understanding the regulatory networks that modulate plant defense responses.

Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance.

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Caroline Borges Bevilacqua

Full Text Available Rice (Oryza sativa L. cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1 classify the subspecies (ssp. grouping (japonica or indica of 21 accessions; 2 evaluate their sensitivity to cold stress; and 3 analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and

An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola.

Science.gov (United States)

Nagel, Raimund; Turrini, Paula C G; Nett, Ryan S; Leach, Jan E; Verdier, Valérie; Van Sluys, Marie-Anne; Peters, Reuben J

2017-05-01

Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA 4 , an additional step beyond production of the penultimate precursor GA 9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA 4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Dissection of cis-regulatory element architecture of the rice oleosin gene promoters to assess abscisic acid responsiveness in suspension-cultured rice cells.

Science.gov (United States)

Kim, Sol; Lee, Soo-Bin; Han, Chae-Seong; Lim, Mi-Na; Lee, Sung-Eun; Yoon, In Sun; Hwang, Yong-Sic

2017-08-01

Oleosins are the most abundant proteins in the monolipid layer surrounding neutral storage lipids that form oil bodies in plants. Several lines of evidence indicate that they are physiologically important for the maintenance of oil body structure and for mobilization of the lipids stored inside. Rice has six oleosin genes in its genome, the expression of all of which was found to be responsive to abscisic acid (ABA) in our examination of mature embryo and aleurone tissues. The 5'-flanking region of OsOle5 was initially characterized for its responsiveness to ABA through a transient expression assay system using the protoplasts from suspension-cultured rice cells. A series of successive deletions and site-directed mutations identified five regions critical for the hormonal induction of its promoter activity. A search for cis-acting elements in these regions deposited in a public database revealed that they contain various promoter elements previously reported to be involved in the ABA response of various genes. A gain-of-function experiment indicated that multiple copies of all five regions were sufficient to provide the minimal promoter with a distinct ABA responsiveness. Comparative sequence analysis of the short, but still ABA-responsive, promoters of OsOle genes revealed no common modular architecture shared by them, indicating that various distinct promoter elements and independent trans-acting factors are involved in the ABA responsiveness of rice oleosin multigenes. Copyright © 2017 Elsevier GmbH. All rights reserved.

Overexpression of miR169o, an Overlapping microRNA in Response to Both Nitrogen Limitation and Bacterial Infection, Promotes Nitrogen Use Efficiency and Susceptibility to Bacterial Blight in Rice.

Science.gov (United States)

Chao, Yu; Chen, Yutong; Cao, Yaqian; Chen, Huamin; Wang, Jichun; Bi, Yong-Mei; Tian, Fang; Yang, Fenghuan; Rothstein, Steven J; Zhou, Xueping; He, Chenyang

2018-03-15

Limiting nitrogen (N) supply contributes to improved resistance to bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) in susceptible rice (Oryza sativa). To understand the regulatory roles of microRNAs in this phenomenon, sixty-three differentially-expressed overlapping miRNAs in response to Xoo infection and N-limitation stress in rice were identified through deep RNA-sequence and stem loop qRT-PCR. Among these, miR169o was further assessed as a typical overlapping miRNA through the overexpression of the miR169o primary gene. Osa-miR169o-OX plants were taller, and had more biomass accumulation with significantly increased nitrate and total amino acid contents in roots than wild type (WT). Transcript level assays showed that under different N supply conditions miR169o opposite regulated NRT2 which is reduced under normal N supply condition but remarkably induced under N limiting stress. On the other hand, osa-miR169o-OX plants also displayed increased disease lesion lengths and reduced transcriptional levels of defense gene (PR1b, PR10a, PR10b and PAL) compared with WT after inoculation with Xoo. In addition, miR169o impeded Xoo-mediated NRT transcription. Therefore, the overlapping miR169o contributes to increase N use efficiency and negatively regulates the resistance to bacterial blight in rice. Consistently, transient expression of NF-YAs in rice protoplast promoted the transcripts of PR genes and NRT2 genes, while reduced the transcripts of NRT1 genes. Our results provide novel and additional insights into the coordinated regulatory mechanisms of crosstalk between Xoo infection and N-deficiency responses in rice.

A translational study on looming-evoked defensive response and the underlying subcortical pathway in autism.

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Hu, Yu; Chen, Zhuoming; Huang, Lu; Xi, Yue; Li, Bingxiao; Wang, Hong; Yan, Jiajian; Lee, Tatia M C; Tao, Qian; So, Kwok-Fai; Ren, Chaoran

2017-11-07

Rapidly approaching objects indicating threats can induce defensive response through activating a subcortical pathway comprising superior colliculus (SC), lateral posterior nucleus (LP), and basolateral amygdala (BLA). Abnormal defensive response has been reported in autism, and impaired synaptic connections could be the underlying mechanism. Whether the SC-LP-BLA pathway processes looming stimuli abnormally in autism is not clear. Here, we found that looming-evoked defensive response is impaired in a subgroup of the valproic acid (VPA) mouse model of autism. By combining the conventional neurotracer and transneuronal rabies virus tracing techniques, we demonstrated that synaptic connections in the SC-LP-BLA pathway were abnormal in VPA mice whose looming-evoked defensive responses were absent. Importantly, we further translated the finding to children with autism and observed that they did not present looming-evoked defensive response. Furthermore, the findings of the DTI with the probabilistic tractography showed that the structural connections of SC-pulvinar-amygdala in autism children were weak. The pulvinar is parallel to the LP in a mouse. Because looming-evoked defensive response is innate in humans and emerges much earlier than do social and language functions, the absence of defensive response could be an earlier sign of autism in children.

Glycemic Response to Black Beans and Chickpeas as Part of a Rice Meal: A Randomized Cross-Over Trial.

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Winham, Donna M; Hutchins, Andrea M; Thompson, Sharon V

2017-10-04

Legumes, such as black beans ( Phaseolus vulgaris L.) and chickpeas ( Cicer arietinum L.), have a low glycemic index, and may reduce the glycemic load of meals in which they are included. Although the low glycemic response of beans consumed alone has been documented, few studies have examined the glycemic response to traditional food combinations such as black beans and rice or chickpeas and rice. This randomized cross-over study examined the glycemic and insulinemic impact of 50 grams of available carbohydrate from three test meals: plain white rice (control), black beans with rice, and chickpeas with rice among healthy adult women ( n = 12, 18-65 years). Treatments were consumed on different mornings, a minimum of 7 days apart. Blood samples were collected at time 0 (fasting), and at 30, 60, 90, and 120 min postprandial, and were subsequently analyzed for glucose and insulin concentrations. Glucose response based on the incremental area under the curve showed a significant difference by treatment ( p = 0.027). Changes in blood glucose concentrations were significantly different for the black bean meal and the chickpea meal in comparison to rice alone at 60 min ( p = 0.026 and p = 0.024), 90 min ( p = 0.001 and p = 0.012) and 120 min post prandial ( p = 0.024; black bean meal). Findings indicate that combinations of black beans and chickpeas with white rice improve glycemic response, providing evidence that has promising implications for dietary guidance to reduce postprandial glucose and related health risks through traditional food patterns.

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

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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.

RiceMetaSys for salt and drought stress responsive genes in rice: a web interface for crop improvement.

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Sandhu, Maninder; Sureshkumar, V; Prakash, Chandra; Dixit, Rekha; Solanke, Amolkumar U; Sharma, Tilak Raj; Mohapatra, Trilochan; S V, Amitha Mithra

2017-09-30

Genome-wide microarray has enabled development of robust databases for functional genomics studies in rice. However, such databases do not directly cater to the needs of breeders. Here, we have attempted to develop a web interface which combines the information from functional genomic studies across different genetic backgrounds with DNA markers so that they can be readily deployed in crop improvement. In the current version of the database, we have included drought and salinity stress studies since these two are the major abiotic stresses in rice. RiceMetaSys, a user-friendly and freely available web interface provides comprehensive information on salt responsive genes (SRGs) and drought responsive genes (DRGs) across genotypes, crop development stages and tissues, identified from multiple microarray datasets. 'Physical position search' is an attractive tool for those using QTL based approach for dissecting tolerance to salt and drought stress since it can provide the list of SRGs and DRGs in any physical interval. To identify robust candidate genes for use in crop improvement, the 'common genes across varieties' search tool is useful. Graphical visualization of expression profiles across genes and rice genotypes has been enabled to facilitate the user and to make the comparisons more impactful. Simple Sequence Repeat (SSR) search in the SRGs and DRGs is a valuable tool for fine mapping and marker assisted selection since it provides primers for survey of polymorphism. An external link to intron specific markers is also provided for this purpose. Bulk retrieval of data without any limit has been enabled in case of locus and SSR search. The aim of this database is to facilitate users with a simple and straight-forward search options for identification of robust candidate genes from among thousands of SRGs and DRGs so as to facilitate linking variation in expression profiles to variation in phenotype. Database URL: http://14.139.229.201.

JAZ repressors: Possible Involvement in Nutrients Deficiency Response in Rice and Chickpea

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Ajit P. Singh

2015-11-01

Full Text Available Jasmonates (JA are well-known phytohormones which play important roles in plant development and defence against pathogens. Jasmonate ZIM domain (JAZ proteins are plant-specific proteins and act as transcriptional repressors of JA-responsive genes. JA regulates both biotic and abiotic stress responses in plants; however, its role in nutrient deficiency responses is very elusive. Although, JA is well-known for root growth inhibition, little is known about behaviour of JAZ genes in response to nutrient deficiencies, under which root architectural alteration is an important adaptation. Using protein sequence homology and a conserved-domains approach, here we identify ten novel JAZ genes from the recently sequenced Chickpea genome, which is one of the most nutrient efficient crops. Both rice and chickpea JAZ genes express in tissue- and stimuli-specific manners. Many of which are preferentially expressed in root. Our analysis further showed differential expression of JAZ genes under macro (NPK and micronutrients (Zn, Fe deficiency in rice and chickpea roots. While both rice and chickpea JAZ genes showed a certain level of specificity towards type of nutrient deficiency, generally majority of them showed induction under K deficiency. Generally, JAZ genes showed an induction at early stages of stress and expression declined at later stages of macro-nutrient deficiency. Our results suggest that JAZ genes might play a role in early nutrient deficiency response both in monocot and dicot roots, and information generated here can be further used for understanding the possible roles of JA in root architectural alterations for nutrient deficiency adaptations

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

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Benoît eDrogue

2014-11-01

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

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

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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.

Role of OsWAK124, a rice wall-associated kinase, in response to environmental heavy metal stresses

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Yin, X.; Hou, X.

2017-01-01

Members of the Arabidopsis cell wall-associated kinase (WAK) family play important roles in both development and stress responses. There are about one hundred and twenty five OsWAKs annotated in the rice genome but their functions in rice growth and development are largely unknown. In this paper, we reported a functional role of the OsWAK124 (Os12g0266200) in rice heavy metal responses. Confocal GFP experiments located OsWAK124 in the cell wall and analyses of OsWAK124 promoter GUS transgenic lines suggested that OsWAK124 promoter is primarily active at the meristematic tissues under normal growth condition. Under stress conditions, however, OsWAK124 promoter activity is induced in non-meristematic tissues, such as leaf, stem and root, and the activity in the meristematic tissues is further enhanced. Various transgenic rice lines carrying either RNA interference (RNAi) or overexpression constructs were generated. Transgenic lines were tested for their responses to various stress conditions including salicylic acid, NaCl, AlCl/sub 3/, CuSO/sub 4/ and CdSO/sub 4/. Our analyses showed that rice seedlings overexpressing OsWAK124 are more resistant to the three tested heavy metals (Al, Cu, and Cd), which suggested that OsWAK124, like some Arabidopsis WAK members, plays a role in environmental heavy metal stress responses. (author)

Growth responses of NaCl stressed rice (Oryza sativa L.) plants ...

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GREGORY

2010-09-27

Sep 27, 2010 ... Growth responses of NaCl stressed rice (Oryza sativa. L.) plants ... 2008), which is a real threat to human's food security. Existed situation may ..... content and composition of essential oil and minerals in black cumin. (Nigella ...

Reducing Defensive Responses to Thoughts of Death: Meditation, Mindfulness, and Buddhism.

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Park, Young Chin; Pyszczynski, Tom

2017-08-24

Three studies investigated the effects of meditation on responses to reminders of death. Study 1 took a quasi-experimental approach, comparing defensive responses to mortality salience (MS) of South Korean participants with varying levels of experience with Buddhism and meditation. Whereas non-Buddhists without meditation showed the typical increase in worldview defense after mortality salience (MS), this effect was not found among non-Buddhists immediately after an initial meditation experience, nor among lay Buddhists who meditated regularly or Buddhist monks with intensive meditation experience. Study 2, a fully randomized experiment, showed that MS increased worldview defense among South Koreans at a meditation training who were assessed before meditating but not among participants assessed after their first meditation experience. Study 3 showed that whereas American students without prior meditation experience showed increased worldview defense and suppression of death-related thoughts after MS, these effects were eliminated immediately after an initial meditation experience. Death thought accessibility mediated the effect of MS on worldview defense without meditation, but meditation eliminated this mediation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Arabidopsis thaliana defense response to the ochratoxin A-producing strain (Aspergillus ochraceus 3.4412).

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Hao, Junran; Wu, Weihong; Wang, Yan; Yang, Zhuojun; Liu, Yang; Lv, Yangjun; Zhai, Yanan; Yang, Jing; Liang, Zhihong; Huang, Kunlun; Xu, Wentao

2015-05-01

OTA-producing strain Aspergillus ochraceus induced necrotic lesions, ROS accumulation and defense responses in Arabidopsis . Primary metabolic and defense-related proteins changed in proteomics. Ascorbate-glutathione cycle and voltage-dependent anion-selective channel proteins fluctuated. Mycotoxigenic fungi, as widespread contaminants by synthesizing mycotoxins in pre-/post-harvest infected plants and even stored commercial cereals, could usually induce plant-fungi defense responses. Notably, ochratoxin A (OTA) is a nephrotoxic, hepatotoxic, teratogenic, immunotoxic and phytotoxic mycotoxin. Herein, defense responses of model system Arabidopsis thaliana detached leaves to infection of Aspergillus ochraceus 3.4412, an OTA high-producing strain, were studied from physiological, proteomic and transcriptional perspectives. During the first 72 h after inoculation (hai), the newly formed hypersensitive responses-like lesions, decreased chlorophyll content, accumulated reactive oxygen species and upregulated defense genes expressions indicated the defense response was induced in the leaves with the possible earlier motivated jasmonic acid/ethylene signaling pathways and the later salicylic acid-related pathway. Moreover, proteomics using two-dimensional gel electrophoresis 72 hai showed 16 spots with significantly changed abundance and 13 spots corresponding to 12 unique proteins were successfully identified by MALDI-TOF/TOF MS/MS. Of these, six proteins were involved in basic metabolism and four in defense-related processes, which included glutathione-S-transferase F7, voltage-dependent anion-selective channel protein 3 (VDAC-3), osmotin-like protein OSM34 and blue copper-binding protein. Verified from proteomic and/or transcriptional perspectives, it is concluded that the primary metabolic pathways were suppressed with the ascorbate-glutathione cycle fluctuated in response to A. ochraceus and the modulation of VDACs suggested the possibility of structural damage and

Parametric optimization of rice bran oil extraction using response surface methodology

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Ahmad Syed W.

2016-09-01

Full Text Available Use of bran oil in various edible and nonedible industries is very common. In this research work, efficient and optimized methodology for the recovery of rice bran oil has been investigated. The present statistical study includes parametric optimization, based on experimental results of rice bran oil extraction. In this study, three solvents, acetone, ethanol and solvent mixture (SM [acetone: ethanol (1:1 v/v] were employed in extraction investigations. Response surface methodology (RSM, an optimization technique, was exploited for this purpose. A five level central composite design (CCD consisting four operating parameter, like temperature, stirring rate, solvent-bran ratio and contact time were examined to optimize rice bran oil extraction. Experimental results showed that oil recovery can be enhanced from 71% to 82% when temperature, solvent-bran ratio, stirring rate and contact time were kept at 55°C, 6:1, 180 rpm and 45 minutes, respectively while fixing the pH of the mixture at 7.1.

Defense response in Nopal Cladodes infiltrated with Salmonella Typhimurium

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Foodborne outbreaks associated with fresh produce have increased in recent years. Pre-harvest contamination of fresh produce via irrigation water, soil, or other animal vectors may be responsible for many of these outbreaks. We evaluated defense response of nopal plants when contaminated in intern...

Involvement of Antioxidative Defense System in Rice Seedlings Exposed to Aluminum Toxicity and Phosphorus Deficiency

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Tian-rong GUO

2012-09-01

Full Text Available Plants growing in acid soils may suffer both phosphorus (P deficiency and aluminum (Al toxicity. Hydroponic experiments were undertaken to assess the single and combination effects of Al toxicity and low P stress on seedling growth, chlorophyll and proline contents, antioxidative response and lipid peroxidation of two rice genotypes (Yongyou 8 and Xiushui 132 differing in Al tolerance. Al toxicity and P deficiency both inhibited rice seedling growth. The development of toxic symptoms was characterized by reduced chlorophyll content, increased proline and malondialdehyde contents in both roots and leaves, and increased peroxidase and superoxide dismutase activities in roots, but decreased in leaves. The stress condition induced more severe growth inhibition and oxidative stress in Yongyou 8, and Xiushui 132 showed higher tolerance to both Al toxicity and P deficiency. P deficiency aggravated Al toxicity to plant growth and induced more severe lipid peroxidation.

Evaluation of mating type distribution and genetic diversity of three Magnaporthe oryzae avirulence genes, PWL-2, AVR-Pii and Avr-Piz-t, in Thailand rice blast isolates

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Thanyaluk Sirisathaworn

2017-02-01

Full Text Available Rice blast disease, caused by the filamentous ascomycete fungus Magnaporthe oryzae (anamorph Pyricularia oryzae, has been ranked among the most important diseases of rice. The molecular mechanisms against this fungus follow the idea of “gene-for-gene interaction”, in which a plant resistance (R gene product recognizes a fungal avirulence (Avr effector and triggers the defense response. However, the Avr genes have been shown to be rapidly evolving resulting in high levels of genetic diversity. This study investigated genetic diversity that is influenced by sexual recombination and mutation for the adaptation of rice blast fungus to overcome the defense response. Mating type distribution and the nucleotide sequence variation of three avirulence genes were evaluated—PWL-2, Avr-Pii and Avr-Piz-t. In total, 77 rice blast isolates collected from infected rice plants in northern, northeastern and central Thailand in 2005, 2010 and 2012, were used in the analysis with mating type and avirulence gene-specific primers. The results revealed that all the tested blast isolates belonged to the mating type MAT1-2, suggesting a lack of sexual recombination within the population. The successful rates of PWL-2, Avr-Pii and Avr-Piz-t gene-specific primer amplification were 100%, 60% and 54%, respectively. Base substitution mutation was observed in coding regions of the Avr-Pii and Avr-Piz-t genes. Although these results showed a low level of genetic diversity in Thai rice blast isolates, non-synonymous mutations did occur which revealed common mechanisms of selective pressure that are prone to adaptation of Avr genes. The information on nucleotide sequence variation and the genetic diversity of Avr genes obtained from this study could be useful for planning novel strategies in the development of rice breeding programs in Thailand.

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

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

2014-07-01

fine powder followed by extraction of total RNA whose quantity and quality were confirmed for downstream analysis. Selected gene expression profiles of internal control, DNA repair/damage, oxidative stress, photosynthesis, and defense/stress functions were examined by semi-quantitative RT-PCR. Results showed that low-level gamma radiation differentially regulated the expression of genes at both early (6 h, DNA repair/damage-related) genes and late (72 h, defense/stress-related). Fifth, genome-wide transcript profiling of genes at 6 and 72 h time points was performed using a rice 4 x 44K custom (eARRAY, AMAdid-017845) oligo DNA microarray chip (G2514F: Agilent Technologies, Palo Alto, CA, USA). Results revealed the induction of 4481 and 2291 genes greater than 2-fold, and the suppression of 3740 and 1474 lesser than 0.5-fold at 6 and 72 h post-exposure, respectively. Inventory of large number of gamma radiation-responsive genes in leaves provides new information and increased knowledge on the potential regulatory processes in rice. Document available in abstract form only. (authors)

Methyl jasmonate induced resistance in cheniere rice and soybean plants

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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.

Arabidopsis thaliana: A model host plant to study plant-pathogen interaction using rice false smut isolates of Ustilaginoidea virens

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Mebeaselassie eAndargie

2016-02-01

Full Text Available Rice false smut fungus which is a biotrophic fungal pathogen causes an important rice disease and bring a severe damage where rice is cultivated. We established a new fungal-plant pathosystem where Ustilaginoidea virens was able to interact compatibly with the model plant Arabidopsis thaliana. Disease symptoms were apparent on the leaves of the plants after 6 days of post inoculation in the form of chlorosis. Cytological studies showed that U. virens caused a heavy infestation inside the cells of the chlorotic tissues. Development and colonization of aerial mycelia in association with floral organ, particularly on anther and stigma of the flowers after 3 weeks of post inoculation was evident which finally caused infection on the developing seeds and pod tissues. The fungus adopts a uniquely biotrophic infection strategy in roots and spreads without causing a loss of host cell viability. We have also demonstrated that U. virens isolates infect Arabidopsis and the plant subsequently activates different defense response mechanisms which are witnessed by the expression of pathogenesis-related genes, PR-1, PR-2, PR-5, PDF1.1 and PDF1.2. The established A. thaliana–U. virens pathosystem will now permit various follow-up molecular genetics and gene expression experiments to be performed to identify the defense signals and responses that restrict fungal hyphae colonization in planta and also provide initial evidence for tissue-adapted fungal infection strategies.

Maternal programming of defensive responses through sustained effects on gene expression.

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Zhang, Tie-Yuan; Bagot, Rose; Parent, Carine; Nesbitt, Cathy; Bredy, Timothy W; Caldji, Christian; Fish, Eric; Anisman, Hymie; Szyf, Moshe; Meaney, Michael J

2006-07-01

There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype. In this paper we review data from the rat that suggest comparable forms of maternal effects on defensive responses stress, which are mediated by the effects of variations in maternal behavior on gene expression. Under conditions of environmental adversity maternal effects enhance the capacity for defensive responses in the offspring. In mammals, these effects appear to 'program' emotional, cognitive and endocrine systems towards increased sensitivity to adversity. In environments with an increased level of adversity, such effects can be considered adaptive, enhancing the probability of offspring survival to sexual maturity; the cost is that of an increased risk for multiple forms of pathology in later life.

Computational prediction and experimental verification of HVA1-like abscisic acid responsive promoters in rice (Oryza sativa).

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Ross, Christian; Shen, Qingxi J

2006-09-01

Abscisic acid (ABA) is one of the central plant hormones, responsible for controlling both maturation and germination in seeds, as well as mediating adaptive responses to desiccation, injury, and pathogen infection in vegetative tissues. Thorough analyses of two barley genes, HVA1 and HVA22, indicate that their response to ABA relies on the interaction of two cis-acting elements in their promoters, an ABA response element (ABRE) and a coupling element (CE). Together, they form an ABA response promoter complex (ABRC). Comparison of promoters of barley HVA1 and it rice orthologue indicates that the structures and sequences of their ABRCs are highly similar. Prediction of ABA responsive genes in the rice genome is then tractable to a bioinformatics approach based on the structures of the well-defined barley ABRCs. Here we describe a model developed based on the consensus, inter-element spacing and orientations of experimentally determined ABREs and CEs. Our search of the rice promoter database for promoters that fit the model has generated a partial list of genes in rice that have a high likelihood of being involved in the ABA signaling network. The ABA inducibility of some of the rice genes identified was validated with quantitative reverse transcription PCR (QPCR). By limiting our input data to known enhancer modules and experimentally derived rules, we have generated a high confidence subset of ABA-regulated genes. The results suggest that the pathways by which cereals respond to biotic and abiotic stresses overlap significantly, and that regulation is not confined to the level transcription. The large fraction of putative regulatory genes carrying HVA1-like enhancer modules in their promoters suggests the ABA signal enters at multiple points into a complex regulatory network that remains largely unmapped.

Stage-Related Defense Response Induction in Tomato Plants by Nesidiocoris tenuis

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Naselli, Mario; Urbaneja, Alberto; Siscaro, Gaetano; Jaques, Josep A.; Zappalà, Lucia; Flors, Víctor; Pérez-Hedo, Meritxell

2016-01-01

The beneficial effects of direct predation by zoophytophagous biological control agents (BCAs), such as the mirid bug Nesidiocoris tenuis, are well-known. However, the benefits of zoophytophagous BCAs’ relation with host plants, via induction of plant defensive responses, have not been investigated until recently. To date, only the females of certain zoophytophagous BCAs have been demonstrated to induce defensive plant responses in tomato plants. The aim of this work was to determine whether nymphs, adult females, and adult males of N. tenuis are able to induce defense responses in tomato plants. Compared to undamaged tomato plants (i.e., not exposed to the mirid), plants on which young or mature nymphs, or adult males or females of N. tenuis fed and developed were less attractive to the whitefly Bemisia tabaci, but were more attractive to the parasitoid Encarsia formosa. Female-exposed plants were more repellent to B. tabaci and more attractive to E. formosa than were male-exposed plants. When comparing young- and mature-nymph-exposed plants, the same level of repellence was obtained for B. tabaci, but mature-nymph-exposed plants were more attractive to E. formosa. The repellent effect is attributed to the signaling pathway of abscisic acid, which is upregulated in N. tenuis-exposed plants, whereas the parasitoid attraction was attributed to the activation of the jasmonic acid signaling pathway. Our results demonstrate that all motile stages of N. tenuis can trigger defensive responses in tomato plants, although these responses may be slightly different depending on the stage considered. PMID:27472328

Gibberellins regulate iron deficiency-response by influencing iron transport and translocation in rice seedlings (Oryza sativa).

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Wang, Baolan; Wei, Haifang; Xue, Zhen; Zhang, Wen-Hao

2017-04-01

Gibberellins (GAs) are a class of plant hormones with diverse functions. However, there has been little information on the role of GAs in response to plant nutrient deficiency. To evaluate the roles of GAs in regulation of Fe homeostasis, the effects of GA on Fe accumulation and Fe translocation in rice seedlings were investigated using wild-type, a rice mutant ( eui1 ) displaying enhnaced endogenous GA concentrations due to a defect in GA deactivation, and transgenic rice plants overexpressing OsEUI . Exposure to Fe-deficient medium significantly reduced biomass of rice plants. Both exogenous application of GA and an endogenous increase of bioactive GA enhanced Fe-deficiency response by exaggerating foliar chlorosis and reducing growth. Iron deficiency significantly suppressed production of GA 1 and GA 4 , the biologically active GAs in rice. Exogenous application of GA significantly decreased leaf Fe concentration regardless of Fe supply. Iron concentration in shoot of eui1 mutants was lower than that of WT plants under both Fe-sufficient and Fe-deficient conditions. Paclobutrazol, an inhibitor of GA biosynthesis, alleviated Fe-deficiency responses, and overexpression of EUI significantly increased Fe concentration in shoots and roots. Furthermore, both exogenous application of GA and endogenous increase in GA resulting from EUI mutation inhibited Fe translocation within shoots by suppressing OsYSL2 expression, which is involved in Fe transport and translocation. The novel findings provide compelling evidence to support the involvement of GA in mediation of Fe homeostasis in strategy II rice plants by negatively regulating Fe transport and translocation. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Erwinia carotovora elicitors and Botrytis cinerea activate defense responses in Physcomitrella patens

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Bentancor Marcel

2007-10-01

Full Text Available Abstract Background Vascular plants respond to pathogens by activating a diverse array of defense mechanisms. Studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. However, very little is known about the infection and defense responses of the bryophyte, Physcomitrella patens, to well-studied phytopathogens. The purpose of this study was to determine: i whether two representative broad host range pathogens, Erwinia carotovora ssp. carotovora (E.c. carotovora and Botrytis cinerea (B. cinerea, could infect Physcomitrella, and ii whether B. cinerea, elicitors of a harpin (HrpN producing E.c. carotovora strain (SCC1 or a HrpN-negative strain (SCC3193, could cause disease symptoms and induce defense responses in Physcomitrella. Results B. cinerea and E.c. carotovora were found to readily infect Physcomitrella gametophytic tissues and cause disease symptoms. Treatments with B. cinerea spores or cell-free culture filtrates from E.c. carotovoraSCC1 (CF(SCC1, resulted in disease development with severe maceration of Physcomitrella tissues, while CF(SCC3193 produced only mild maceration. Although increased cell death was observed with either the CFs or B. cinerea, the occurrence of cytoplasmic shrinkage was only visible in Evans blue stained protonemal cells treated with CF(SCC1 or inoculated with B. cinerea. Most cells showing cytoplasmic shrinkage accumulated autofluorescent compounds and brown chloroplasts were evident in a high proportion of these cells. CF treatments and B. cinerea inoculation induced the expression of the defense-related genes: PR-1, PAL, CHS and LOX. Conclusion B. cinerea and E.c. carotovora elicitors induce a defense response in Physcomitrella, as evidenced by enhanced expression of conserved plant defense-related genes. Since cytoplasmic shrinkage is the most common morphological change observed in plant PCD, and that harpins and B

Evaluating Crossbred Red Rice Variants for Postprandial Glucometabolic Responses: A Comparison with Commercial Varieties

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Chee-Hee Se

2016-05-01

Full Text Available Consumption of white rice predisposes some Asian populations to increased risk of type 2 diabetes. We compared the postprandial glucometabolic responses to three newly-developed crossbred red rice variants (UKMRC9, UKMRC10, UKMRC11 against three selected commercial rice types (Thai red, Basmati white, Jasmine white using 50-g carbohydrate equivalents provided to 12 normoglycaemic adults in a crossover design. Venous blood was drawn fasted and postprandially for three hours. Glycaemic (GI and insulin (II indices, incremental areas-under-the-curves for glucose and insulin (IAUCins, indices of insulin sensitivity and secretion, lactate and peptide hormones (motilin, neuropeptide-Y, orexin-A were analyzed. The lowest to highest trends for GI and II were similar i.e., UKMRC9 < Basmati < Thai red < UKMRC10 < UKMRC11 < Jasmine. Postprandial insulinaemia and IAUCins of only UKMRC9 were significantly the lowest compared to Jasmine. Crude protein and fiber content correlated negatively with the GI values of the test rice. Although peptide hormones were not associated with GI and II characteristics of test rice, early and late phases of prandial neuropeptide-Y changes were negatively correlated with postprandial insulinaemia. This study indicated that only UKMRC9 among the new rice crossbreeds could serve as an alternative cereal option to improve diet quality of Asians with its lowest glycaemic and insulinaemic burden.

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

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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.

Response of Nerica Rice to Nitrogen Fertilization

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R Shultana

2015-12-01

Full Text Available An experiment was conducted during T. Aman season, 2014 at the Agronomy Research Field, Bangladesh Rice Research Institute, Gazipur to determine the optimum rate of nitrogen fertilizer for higher yield in nerica rice. The experiment comprised of three rice varieties viz. NERICA1, NERICA10 and BRRI dhan57; and five nitrogen levels viz. 0, 23, 46, 69 and 92 kg ha-1. The rice var. BRRI dhan57 with 69 and 92 kg N ha-1 produced significantly identical with higher panicles m-2. But NERICA1 and NERICA10 produced higher number of panicles with 46 and 69 kg N ha-1, respectively. However, BRRI dhan57 with 46 kg N ha-1 produced highest grains panicle-1 but NERICA1 and NERICA10 produced higher number of grains panicle-1 with 23 kg N ha-1. The highest percentage of sterility was recorded in NERICA10 with 69 kg N ha-1. The regression analysis gave the optimum dose of nitrogen for NERICA1, NERICA10 and BRRI dhan57 which were 69.25, 74.25 and 85.75 kg N ha-1, respectively.

Overcompensation of herbivore reproduction through hyper-suppression of plant defenses in response to competition.

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Schimmel, Bernardus C J; Ataide, Livia M S; Chafi, Rachid; Villarroel, Carlos A; Alba, Juan M; Schuurink, Robert C; Kant, Merijn R

2017-06-01

Spider mites are destructive arthropod pests on many crops. The generalist herbivorous mite Tetranychus urticae induces defenses in tomato (Solanum lycopersicum) and this constrains its fitness. By contrast, the Solanaceae-specialist Tetranychus evansi maintains a high reproductive performance by suppressing tomato defenses. Tetranychus evansi outcompetes T. urticae when infesting the same plant, but it is unknown whether this is facilitated by the defenses of the plant. We assessed the extent to which a secondary infestation by a competitor affects local plant defense responses (phytohormones and defense genes), mite gene expression and mite performance. We observed that T. evansi switches to hyper-suppression of defenses after its tomato host is also invaded by its natural competitor T. urticae. Jasmonate (JA) and salicylate (SA) defenses were suppressed more strongly, albeit only locally at the feeding site of T. evansi, upon introduction of T. urticae to the infested leaflet. The hyper-suppression of defenses coincided with increased expression of T. evansi genes coding for salivary defense-suppressing effector proteins and was paralleled by an increased reproductive performance. Together, these observations suggest that T. evansi overcompensates its reproduction through hyper-suppression of plant defenses in response to nearby competitors. We hypothesize that the competitor-induced overcompensation promotes competitive population growth of T. evansi on tomato. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

IBR5 Modulates Temperature-Dependent, R Protein CHS3-Mediated Defense Responses in Arabidopsis.

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Jingyan Liu

2015-10-01

Full Text Available Plant responses to low temperature are tightly associated with defense responses. We previously characterized the chilling-sensitive mutant chs3-1 resulting from the activation of the Toll and interleukin 1 receptor-nucleotide binding-leucine-rich repeat (TIR-NB-LRR-type resistance (R protein harboring a C-terminal LIM (Lin-11, Isl-1 and Mec-3 domains domain. Here we report the identification of a suppressor of chs3, ibr5-7 (indole-3-butyric acid response 5, which largely suppresses chilling-activated defense responses. IBR5 encodes a putative dual-specificity protein phosphatase. The accumulation of CHS3 protein at chilling temperatures is inhibited by the IBR5 mutation. Moreover, chs3-conferred defense phenotypes were synergistically suppressed by mutations in HSP90 and IBR5. Further analysis showed that IBR5, with holdase activity, physically associates with CHS3, HSP90 and SGT1b (Suppressor of the G2 allele of skp1 to form a complex that protects CHS3. In addition to the positive role of IBR5 in regulating CHS3, IBR5 is also involved in defense responses mediated by R genes, including SNC1 (Suppressor of npr1-1, Constitutive 1, RPS4 (Resistance to P. syringae 4 and RPM1 (Resistance to Pseudomonas syringae pv. maculicola 1. Thus, the results of the present study reveal a role for IBR5 in the regulation of multiple R protein-mediated defense responses.

Gene expression profiles deciphering rice phenotypic variation between Nipponbare (Japonica and 93-11 (Indica during oxidative stress.

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Fengxia Liu

Full Text Available Rice is a very important food staple that feeds more than half the world's population. Two major Asian cultivated rice (Oryza sativa L. subspecies, japonica and indica, show significant phenotypic variation in their stress responses. However, the molecular mechanisms underlying this phenotypic variation are still largely unknown. A common link among different stresses is that they produce an oxidative burst and result in an increase of reactive oxygen species (ROS. In this study, methyl viologen (MV as a ROS agent was applied to investigate the rice oxidative stress response. We observed that 93-11 (indica seedlings exhibited leaf senescence with severe lesions under MV treatment compared to Nipponbare (japonica. Whole-genome microarray experiments were conducted, and 1,062 probe sets were identified with gene expression level polymorphisms between the two rice cultivars in addition to differential expression under MV treatment, which were assigned as Core Intersectional Probesets (CIPs. These CIPs were analyzed by gene ontology (GO and highlighted with enrichment GO terms related to toxin and oxidative stress responses as well as other responses. These GO term-enriched genes of the CIPs include glutathine S-transferases (GSTs, P450, plant defense genes, and secondary metabolism related genes such as chalcone synthase (CHS. Further insertion/deletion (InDel and regulatory element analyses for these identified CIPs suggested that there may be some eQTL hotspots related to oxidative stress in the rice genome, such as GST genes encoded on chromosome 10. In addition, we identified a group of marker genes individuating the japonica and indica subspecies. In summary, we developed a new strategy combining biological experiments and data mining to study the possible molecular mechanism of phenotypic variation during oxidative stress between Nipponbare and 93-11. This study will aid in the analysis of the molecular basis of quantitative traits.

Response of Transplanted Aman Rice Varieties to Herbicides in Strip-Tilled Non-Puddled Soil

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Taslima Zahan1

2017-12-01

Full Text Available BACKGROUND: Sensitivity of crop cultivars may vary to commonly used herbicides resulting in potential yield loss and reduce farm profit. Transplanting of rice seedlings in strip-tilled non-puddled field is a new practice for which herbicide tolerant varieties need to select. Therefore, a study was executed at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the response of some popular transplanted aman rice varieties to different herbicides at their recommended rate and to select most tolerant aman rice variety or varieties for strip-tilled non-puddled transplanting. METHODOLOGY: Twelve aman rice varieties (BR11, BRRI dhan33, BRRI dhan39, BRRI dhan44, BRRI dhan46, BRRI dhan49, BRRI dhan51, BRRI dhan52, BRRI dhan56, BRRI dhan57, BRRI hybrid dhan-4 and BINA dhan7 were examined in the study against six herbicides (2 pre-emergence: pyrazosulfuron-ethyl and butachlor; 1 early post-emergence: orthosulfamuron and 3 late post-emergence: acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine along with one untreated manually weed-free control. KEY FINDINGS: The study revealed that aman rice varieties responded differentially to different herbicides. All rice varieties performed better in pyrazosulfuron-ethyl treated plots relative to the other herbicide treated plots and even than the control plots. Pyrazosulfuron-ethyl increased grain yield of all aman rice varieties by 0.6-32.6% over control and butachlor + propanil provided increased grain yield in all rice varieties by 2.0-25.5% except BRRI hybrid dhan-4. The study also disclosed that BRRI dhan57 and BRRI hybrid dhan-4 gone through the yield loss by application of 2,4-D amine and BRRI dhan56 by application of butachlor and orthosulfamuron. Moreover, acetochlor + bensulfuron methyl produced shorter plants and caused yield loss by 7.8-27.1% in all aman rice varieties compared to the control and BRRI dhan39 was the most susceptible

Identification and characterization of salt responsive miRNA-SSR markers in rice (Oryza sativa).

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Mondal, Tapan Kumar; Ganie, Showkat Ahmad

2014-02-10

Salinity is an important abiotic stress that affects agricultural production and productivity. It is a complex trait that is regulated by different molecular mechanisms. miRNAs are non-coding RNAs which are highly conserved and regulate gene expression. Simple sequence repeats (SSRs) are robust molecular markers for studying genetic diversity. Although several SSR markers are available now, challenge remains to identify the trait-specific SSRs which can be used for marker assisted breeding. In order to understand the genetic diversity of salt responsive-miRNA genes in rice, SSR markers were mined from 130 members of salt-responsive miRNA genes of rice and validated among the contrasting panels of tolerant as well as susceptible rice genotypes, each with 12 genotypes. Although 12 miR-SSRs were found to be polymorphic, only miR172b-SSR was able to differentiate the tolerant and susceptible genotypes in 2 different groups. It had also been found that miRNA genes were more diverse in susceptible genotypes than the tolerant one (as indicated by polymorphic index content) which might interfere to form the stem-loop structure of premature miRNA and their subsequent synthesis in susceptible genotypes. Thus, we concluded that length variations of the repeats in salt responsive miRNA genes may be responsible for a possible sensitivity to salinity adaptation. This is the first report of characterization of trait specific miRNA derived SSRs in plants. Copyright © 2013 Elsevier B.V. All rights reserved.

Genes and co-expression modules common to drought and bacterial stress responses in Arabidopsis and rice.

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Rafi Shaik

Full Text Available Plants are simultaneously exposed to multiple stresses resulting in enormous changes in the molecular landscape within the cell. Identification and characterization of the synergistic and antagonistic components of stress response mechanisms contributing to the cross talk between stresses is of high priority to explore and enhance multiple stress responses. To this end, we performed meta-analysis of drought (abiotic, bacterial (biotic stress response in rice and Arabidopsis by analyzing a total of 386 microarray samples belonging to 20 microarray studies and identified approximately 3100 and 900 DEGs in rice and Arabidopsis, respectively. About 38.5% (1214 and 28.7% (272 DEGs were common to drought and bacterial stresses in rice and Arabidopsis, respectively. A majority of these common DEGs showed conserved expression status in both stresses. Gene ontology enrichment analysis clearly demarcated the response and regulation of various plant hormones and related biological processes. Fatty acid metabolism and biosynthesis of alkaloids were upregulated and, nitrogen metabolism and photosynthesis was downregulated in both stress conditions. WRKY transcription family genes were highly enriched in all upregulated gene sets while 'CO-like' TF family showed inverse relationship of expression between drought and bacterial stresses. Weighted gene co-expression network analysis divided DEG sets into multiple modules that show high co-expression and identified stress specific hub genes with high connectivity. Detection of consensus modules based on DEGs common to drought and bacterial stress revealed 9 and 4 modules in rice and Arabidopsis, respectively, with conserved and reversed co-expression patterns.

Molecular Analysis of Rice CIPKs Involved in Both Biotic and Abiotic Stress Responses

Institute of Scientific and Technical Information of China (English)

CHEN Xi-feng; Gu Zhi-min; LIU Feng; MA Bo-jun; ZHANG Hong-sheng

2011-01-01

Plant calcineurin B-like (CBL) proteins have been proposed as important Ca2+ sensors and specifically interact with CBL-interacting protein kinases (CIPKs) in plant-specific calcium signaling.Here,we identified and isolated 15 CIPK genes in a japonica rice variety Nipponbare based on the predicted sequences of rice CIPK gene family.Gene structure analysis showed that these 15 genes were divided into intron-less and intron-rich groups,and OsCIPK3 and OsCIPK24 exhibited alternative splicing in their mature process.The phylogenetic analyses indicated that rice CIPKs shared an ancestor with Arabidopsis and poplar CIPKs.Analyses of gene expression showed that these OsCIPK genes were differentially induced by biotic stresses such as bacterial blight and abiotic stresses (heavy metal such as Hg2+,high salinity,cold and ABA).Interestingly,five OsCIPK genes,OsCIPK1,2,10,11 and 12,were transcriptionally up-regulated after bacterial blight infection whereas four OsCIPK genes,OsCIPK2,10,11 and 14,were induced by all treatments,indicating that some of OsCIPK genes are involved in multiple stress response pathways in plants.Our finding suggests that CIPKs play a key role in both biotic and abiotic stress responses.

A rice kinase-protein interaction map.

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Ding, Xiaodong; Richter, Todd; Chen, Mei; Fujii, Hiroaki; Seo, Young Su; Xie, Mingtang; Zheng, Xianwu; Kanrar, Siddhartha; Stevenson, Rebecca A; Dardick, Christopher; Li, Ying; Jiang, Hao; Zhang, Yan; Yu, Fahong; Bartley, Laura E; Chern, Mawsheng; Bart, Rebecca; Chen, Xiuhua; Zhu, Lihuang; Farmerie, William G; Gribskov, Michael; Zhu, Jian-Kang; Fromm, Michael E; Ronald, Pamela C; Song, Wen-Yuan

2009-03-01

Plants uniquely contain large numbers of protein kinases, and for the vast majority of the 1,429 kinases predicted in the rice (Oryza sativa) genome, little is known of their functions. Genetic approaches often fail to produce observable phenotypes; thus, new strategies are needed to delineate kinase function. We previously developed a cost-effective high-throughput yeast two-hybrid system. Using this system, we have generated a protein interaction map of 116 representative rice kinases and 254 of their interacting proteins. Overall, the resulting interaction map supports a large number of known or predicted kinase-protein interactions from both plants and animals and reveals many new functional insights. Notably, we found a potential widespread role for E3 ubiquitin ligases in pathogen defense signaling mediated by receptor-like kinases, particularly by the kinases that may have evolved from recently expanded kinase subfamilies in rice. We anticipate that the data provided here will serve as a foundation for targeted functional studies in rice and other plants. The application of yeast two-hybrid and TAPtag analyses for large-scale plant protein interaction studies is also discussed.

Effect of Various Types of Herbs on Sensory Properties and Blood Glucosa Response Adan Instant Black Rice

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Bernatal Saragih

2013-06-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE Management based on the carbohydrate diet is very important to do and not to be avoided but how diet and variations of carbohydrate consumed is set mainly the source of rice that does not fast respond to an increase in blood glucose. Therefore, Evaluation of nutritional and instant rice production that is the functional food and have a low glycemic index rice sourced locally as the East Kalimantan native rice black Adan will be very beneficial for health. The aim of this research was to evaluate of the nutritional and effect of various herbal on sensory properties and blood glucose response Adan instant black rice. Adan black rice has a protein content of 8.10%, Fe 3.61 mg/1000g and 3.33 g/100g total dietary fiber and includes a group of rice with low amylose. Organoleptic value of instant rice black Adan produced the most preferred by panellists also from the addition of ginger extract and pandan leaves , water, onion tiwai, tea and last turmeric. The digestibility of starch decreased 19.04 (mg/1000g after being a functional of instant rice black Adan. Difference in reduction of blood glucose levels in volunteers who consumed black Adan instant rice by 14.20 mg/dL, whereas the provision of a reference food (glucose of 71.50 mg/dL, this indicates of instant rice functional black Adan provide availability of glucose in the blood longer available.

Overexpression of Rat Neurons Nitric Oxide Synthase in Rice Enhances Drought and Salt Tolerance.

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Wei Cai

Full Text Available Nitric oxide (NO has been shown to play an important role in the plant response to biotic and abiotic stresses in Arabidopsis mutants with lower or higher levels of endogenous NO. The exogenous application of NO donors or scavengers has also suggested an important role for NO in plant defense against environmental stress. In this study, rice plants under drought and high salinity conditions showed increased nitric oxide synthase (NOS activity and NO levels. Overexpression of rat neuronal NO synthase (nNOS in rice increased both NOS activity and NO accumulation, resulting in improved tolerance of the transgenic plants to both drought and salt stresses. nNOS-overexpressing plants exhibited stronger water-holding capability, higher proline accumulation, less lipid peroxidation and reduced electrolyte leakage under drought and salt conditions than wild rice. Moreover, nNOS-overexpressing plants accumulated less H2O2, due to the observed up-regulation of OsCATA, OsCATB and OsPOX1. In agreement, the activities of CAT and POX were higher in transgenic rice than wild type. Additionally, the expression of six tested stress-responsive genes including OsDREB2A, OsDREB2B, OsSNAC1, OsSNAC2, OsLEA3 and OsRD29A, in nNOS-overexpressing plants was higher than that in the wild type under drought and high salinity conditions. Taken together, our results suggest that nNOS overexpression suppresses the stress-enhanced electrolyte leakage, lipid peroxidation and H2O2 accumulation, and promotes proline accumulation and the expression of stress-responsive genes under stress conditions, thereby promoting increased tolerance to drought and salt stresses.

The impact of seasonal rice price changes on rice self-consumption in farm household of rural Java

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Ani, S. W.; Antriyandarti, E.

2018-03-01

Seasonal rice price changes are very volatile and not predictable. This price changes have a heterogeneous impact on public consumption. The problem of seasonal rice price changes is not only experienced by consumers, but also in the farmers side as producers. The objective of this study is to provide a detail overview and description of the changing seasonal rice self-consumption of farm households in rural Java in response to seasonal rice price changes and income shocks to anticipate seasonal scarcity. This paper constructs a theoretical model to address such seasonality of food deprivation by using one year of seasonally farm household panel data, empirically tests the extent to which farmers in rural Java can smooth their rice self-consumption from season to season in response to income shocks. The result shows that rice farmers increase their rice self-consumption when prices are high.

Enhancement of defense responses by oligandrin against Botrytis ...

African Journals Online (AJOL)

Oligandrin is an elicitin-like protein with a molecular mass of ∼10 kDa secreted by Pythium oligandrum. Here, the effect of oligandrin on defense response against Botrytis cinerea in tomato leaves is reported. Tomato seedlings were pretreated with 5 ml oligandrin (10 g/ml) by root submerging and then inoculated with B.

Comparison of gene co-networks reveals the molecular mechanisms of the rice (Oryza sativa L.) response to Rhizoctonia solani AG1 IA infection.

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Zhang, Jinfeng; Zhao, Wenjuan; Fu, Rong; Fu, Chenglin; Wang, Lingxia; Liu, Huainian; Li, Shuangcheng; Deng, Qiming; Wang, Shiquan; Zhu, Jun; Liang, Yueyang; Li, Ping; Zheng, Aiping

2018-05-05

Rhizoctonia solani causes rice sheath blight, an important disease affecting the growth of rice (Oryza sativa L.). Attempts to control the disease have met with little success. Based on transcriptional profiling, we previously identified more than 11,947 common differentially expressed genes (TPM > 10) between the rice genotypes TeQing and Lemont. In the current study, we extended these findings by focusing on an analysis of gene co-expression in response to R. solani AG1 IA and identified gene modules within the networks through weighted gene co-expression network analysis (WGCNA). We compared the different genes assigned to each module and the biological interpretations of gene co-expression networks at early and later modules in the two rice genotypes to reveal differential responses to AG1 IA. Our results show that different changes occurred in the two rice genotypes and that the modules in the two groups contain a number of candidate genes possibly involved in pathogenesis, such as the VQ protein. Furthermore, these gene co-expression networks provide comprehensive transcriptional information regarding gene expression in rice in response to AG1 IA. The co-expression networks derived from our data offer ideas for follow-up experimentation that will help advance our understanding of the translational regulation of rice gene expression changes in response to AG1 IA.

Co-Ingestion of Rice Bran Soymilk or Plain Soymilk with White Bread: Effects on the Glycemic and Insulinemic Response

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Stefan Gerardus Camps

2018-04-01

Full Text Available The regular consumption of soy products is associated with inverse incidence of type 2 diabetes, and there has been an increasing interest in the glycemia reducing potential of rice bran and its components. In this study, we investigated whether consuming soymilk with the addition of rice bran (fiber can reduce the glycemic response of a carbohydrate meal. Seventeen healthy Asian men (BMI: 18.5–29 kg/m2 participated in this randomized crossover trial. On four occasions, they consumed white bread (two times and white bread with two different soymilks differing in protein and rice bran content. Blood samples were taken to measure glucose and insulin response over a period of 3 hours. Taking the glycemic index (GI value of white bread as a reference value of 100, the GI of white bread when co-ingested with rice bran soymilk (RBS was 83.1 (±7.7 and sugar-free soymilk (SFS was 77.5 (±10.1, both were lower than white bread (p < 0.05. The insulin response of both soymilk treatments was similar to white bread (p > 0.05. The glucose/insulin ratio of RBS and SFS were respectively 43.1 (±6.1 and 60.0 (±17.0 and were lower (p < 0.05 than white bread (123.5 ± 21.1 during the first 30 min. In conclusion, co-ingestion of low amounts of soy protein with a carbohydrate meal stimulated early-phase insulin secretion and thereby increased blood glucose clearance effectiveness. Furthermore, rice bran-fortified soymilk reduced the glycemic response similarly to soymilk with a greater dose of soy protein. Rice bran and its components offer therapeutic potential for glycemic and insulinemic control.

Alterations in growth, oxidative damage, and metal uptake of five aromatic rice cultivars under lead toxicity.

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Ashraf, Umair; Hussain, Saddam; Anjum, Shakeel Ahmad; Abbas, Farhat; Tanveer, Mohsin; Noor, Mehmood Ali; Tang, Xiangru

2017-06-01

Lead (Pb) affects plant growth and its related physio-biochemical functions negatively. The present study investigated the responses of five different fragrant rice cultivars viz., Meixiangzhan (MXZ-2), Xiangyaxiangzhan (XYXZ), Guixiangzhan (GXZ), Basmati-385 (B-385), and Nongxiang-18 (NX-18) to four different Pb concentrations viz., 0, 400, 800 and 1200 μM. Results depicted that Pb toxicity significantly (P rice plants; nonetheless, a significant variation was found in the sensitivity of rice cultivars to Pb toxicity. Soluble sugars increased significantly only at 1200 μM in GXZ and 800 μM in B-385, whilst the maximum reductions in protein contents were observed at 1200 μM Pb for all rice cultivars. Proline contents were reduced for XYXZ and NX-18 at Pb1200 μM. Activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) as well as reduced glutathione (GSH) and oxidized glutathione (GSSG) showed differential behavior among Pb treatments and rice cultivars. Among rice cultivars, GXZ showed better antioxidative defense system under Pb toxicity compared with all other cultivars. For all rice cultivars, the trend for Pb accumulation was recorded as: roots > stems > leaves. Furthermore, significant but negative correlations among Pb uptake and plant height (r = -0.79), tillers per plant (r = -0.91) and plant dry biomass (r = -0.81) were recorded for all rice cultivars whereas the values of translocation factor (TF) from stems to leaves were higher than roots to stems. In sum, Pb reduced the early growth and caused physio-biochemical changes in all rice cultivars, nonetheless, GXZ proved better able to tolerate Pb stress than all other rice cultivars under study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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.

The MAP kinase substrate MKS1 is a regulator of plant defense responses

DEFF Research Database (Denmark)

Andreasson, E.; Jenkins, T.; Brodersen, P.

2005-01-01

Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used...

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

Interactions among spectral components of radiation in the growth responses of rice, tomato and strawberry

International Nuclear Information System (INIS)

Inada, K.; Matsuno, A.

1985-01-01

Effects of spectral components and their ratios of radiation on simultaneous growth responses were investigated with rice, tomato and strawberry plants exposed to lights with a high fluence rate (350 or 408 μmol m -2 s -1 , 400-700 nm) during every daytime. Both elongation growth and Ieaf area development in rice and strawberry were promoted by red (R) but inhibited by blue (B) component depending on the each fluence rate. However, leaf area in tomato responded in opposite direction to these. The elongation growth was remarkably increased with the fluence rate of far-red (FR) in tomato and strawberry, but not in rice. These responses were lineary increased, except FR and UV effects, with logarithmic R/B ratio in rice and strawberry but not in tomato. A very low R/FR ratio caused a strong promotion of both elongation and leaf area in tomato, while it promoted petiole elengation but inhibited leaf area development in strawberry. The elongation and leaf area development responded to R/FR in reverse way between rice and strawberry. Chlorophyll content of leaves was generally decreased with the increase of logarithmic R/B ratio in all the species. Areal weight of leaf and dry weight increment/leaf area were more or less increased with R/B and R/ FR ratios, Dry weight increment varied with the spectral ratios in almost the same way as leaf area, suggesting that spectral dependence of photosynthetic production was not much different between the species. Some discussions were made on the photoreceptor pigments involved in the elongation growth and leaf area development, and on the selection of light quantity to ensure a normal growth of each plant species

Herbivore Oral Secreted Bacteria Trigger Distinct Defense Responses in Preferred and Non-Preferred Host Plants.

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Wang, Jie; Chung, Seung Ho; Peiffer, Michelle; Rosa, Cristina; Hoover, Kelli; Zeng, Rensen; Felton, Gary W

2016-06-01

Insect symbiotic bacteria affect host physiology and mediate plant-insect interactions, yet there are few clear examples of symbiotic bacteria regulating defense responses in different host plants. We hypothesized that plants would induce distinct defense responses to herbivore- associated bacteria. We evaluated whether preferred hosts (horsenettle) or non-preferred hosts (tomato) respond similarly to oral secretions (OS) from the false potato beetle (FPB, Leptinotarsa juncta), and whether the induced defense triggered by OS was due to the presence of symbiotic bacteria in OS. Both horsenettle and tomato damaged by antibiotic (AB) treated larvae showed higher polyphenol oxidase (PPO) activity than those damaged by non-AB treated larvae. In addition, application of OS from AB treated larvae induced higher PPO activity compared with OS from non-AB treated larvae or water treatment. False potato beetles harbor bacteria that may provide abundant cues that can be recognized by plants and thus mediate corresponding defense responses. Among all tested bacterial isolates, the genera Pantoea, Acinetobacter, Enterobacter, and Serratia were found to suppress PPO activity in tomato, while only Pantoea sp. among these four isolates was observed to suppress PPO activity in horsenettle. The distinct PPO suppression caused by symbiotic bacteria in different plants was similar to the pattern of induced defense-related gene expression. Pantoea inoculated FPB suppressed JA-responsive genes and triggered a SA-responsive gene in both tomato and horsenettle. However, Enterobacter inoculated FPB eliminated JA-regulated gene expression and elevated SA-regulated gene expression in tomato, but did not show evident effects on the expression levels of horsenettle defense-related genes. These results indicate that suppression of plant defenses by the bacteria found in the oral secretions of herbivores may be a more widespread phenomenon than previously indicated.

Lead toxicity in rice: effects, mechanisms, and mitigation strategies--a mini review.

Science.gov (United States)

Ashraf, Umair; Kanu, Adam Sheka; Mo, Zhaowen; Hussain, Saddam; Anjum, Shakeel Ahmad; Khan, Imran; Abbas, Rana Nadeem; Tang, Xiangru

2015-12-01

Lead (Pb) is a major environmental pollutant that affects plant morpho-physiological and biochemical attributes. Its higher levels in the environment are not only toxic to human beings but also harmful for plants and soil microbes. We have reviewed the uptake, translocation, and accumulation mechanisms of Pb and its toxic effects on germination, growth, yield, nutrient relation, photosynthesis, respiration, oxidative damage, and antioxidant defense system of rice. Lead toxicity hampers rice germination, root/shoot length, growth, and final yield. It reduces nutrient uptake through roots, disrupts chloroplastic ultrastructure and cell membrane permeability, induces alterations in leaves respiratory activities, produces reactive oxygen species (ROS), and triggers some enzyme and non-enzymatic antioxidants (as defense to oxidative damage). In the end, biochar amendments and phytoremediation technologies have been proposed as soil remediation approaches for Pb tainted soils.

Demethylation of methylmercury in growing rice plants: An evidence of self-detoxification

International Nuclear Information System (INIS)

Xu, Xiaohan; Zhao, Jiating; Li, Yunyun; Fan, Yuqin; Zhu, Nali; Gao, Yuxi; Li, Bai; Liu, Hanyu; Li, Yu-Feng

2016-01-01

Mercury (Hg) is a global pollutant that poses a serious threat to human and the environment. Rice was found as an important source for human exposure to Hg in some areas. In this study, the transportation and transformation of IHg and MeHg in rice plants exposed to IHg or MeHg were investigated. The IHg and MeHg concentrations in rice roots and shoots collected every five days were analyzed by HPLC-ICP-MS and SR-XANES. When exposed to MeHg, the percent of IHg in rice roots and shoots increased while MeHg decreased significantly, suggesting prominent demethylation of MeHg occurred. However no notable MeHg was found in both roots and shoots of rice plant when exposed to IHg. SR-XANES analysis further confirmed the demethylation of MeHg with rice. This study provides a new finding that demethylation of MeHg could occur in growing rice, which may be a self-defense process of rice plant. - Graphical abstract: Inorganic mercury in Rice (Oryza sativa L.) plants exposed to methylmercury was detected: An evidence of rice plant against methylmercury phytotoxicity. Display Omitted - Highlights: • Demethylation of MeHg in rice plant was found in rice root. • Hg in rice roots mainly present as MeHg-SR or RS-Hg-SR form. • MeHg-SR in roots can be gradually transformed to RS-Hg-SR with rice growth. - Demethylation of MeHg in growing rice.

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.

Effects and mechanism of UV-B radiation on rice growth

International Nuclear Information System (INIS)

Gao Xiaoxiao; Gao Zhaohua; Zu Yanqun

2009-01-01

The enhancement of UV-B radiation influences the growth of rice and physiology in different levels and this performances as changes in morphology destroyed photosynthetic system unstable anti-oxidation system changes of endogenous hormone content exacerbated rice diseases decreased biomass and developmental stage delay. Through the establishment of the response index we can evaluate the varietal differences in responses of the rice to UV-B radiation. Reasons for such varietal differences were differences in rice gene physiology and morphology developmental stage and environmental factors. The main mechanism in responses of the rice to UV-B radiation was induction of flavonoid compounds and accumulation of anthocyanins. Based on the analysis of the influence of enhanced UV-B radiation to rice and the varietal differences in responses to UV-B radiation and mechanism of rice the direction of the further research about the relationship between the rice and UV-B was put forward

Differentially expressed genes distributed over chromosomes and implicated in certain biological processes for site insertion genetically modified rice Kemingdao.

Science.gov (United States)

Liu, Zhi; Li, Yunhe; Zhao, Jie; Chen, Xiuping; Jian, Guiliang; Peng, Yufa; Qi, Fangjun

2012-01-01

Release of genetically modified (GM) plants has sparked off intensive debates worldwide partly because of concerns about potential adverse unintended effects of GM plants to the agro system and the safety of foods. In this study, with the aim of revealing the molecular basis for unintended effects of a single site insertion GM Kemingdao (KMD) rice transformed with a synthetic cry1Ab gene, and bridging unintended effects of KMD rice through clues of differentially expressed genes, comparative transcriptome analyses were performed for GM KMD rice and its parent rice of Xiushui11 (XS11). The results showed that 680 differentially expressed transcripts were identified from 30-day old seedlings of GM KMD rice. The absolute majority of these changed expression transcripts dispersed and located over all rice chromosomes, and existed physical distance on chromosome from the insertion site, while only two transcripts were found to be differentially expressed within the 21 genes located within 100 kb up and down-stream of the insertion site. Pathway and biology function analyses further revealed that differentially expressed transcripts of KMD rice were involved in certain biological processes, and mainly implicated in two types of pathways. One type was pathways implicated in plant stress/defense responses, which were considerably in coordination with the reported unintended effects of KMD rice, which were more susceptible to rice diseases compared to its parent rice XS11; the other type was pathways associated with amino acids metabolism. With this clue, new unintended effects for changes in amino acids synthesis of KMD rice leaves were successfully revealed. Such that an actual case was firstly provided for identification of unintended effects in GM plants by comparative transciptome analysis.

Orienting-defense responses and psychophysiological reactivity in isolated clinic versus sustained hypertension.

Science.gov (United States)

García-Vera, María Paz; Sanz, Jesús; Labrador, Francisco J

2007-04-01

This study sought to determine whether patients with white-coat or isolated clinic hypertension (ICH) show, in comparison to patients with sustained hypertension (SH), a defense response pattern to novel stimuli and an enhanced psychophysiological reactivity to stress. Forty-three patients with essential hypertension were divided into two groups after 16 days of self-monitoring blood pressure (BP): ICH (24 men; self-measured BP men; self-measured BP >or= 135/85 mmHg). Defense responses were measured as the cardiac changes to phasic non-aversive auditory stimuli. Psychophysiological reactivity (heart and breath rate, blood volume pulse, electromyography, and skin conductance) was measured during mental arithmetic and video game tasks. The standard deviation of self-measured BPs and the difference between mean BPs at work and at home were used as indicators of cardiovascular reactivity to daily stress. No significant differences were seen in defense responses or psychophysiological reactivity to laboratory or naturally occurring stressors. These results do not support the hypothesis that ICH can be explained in terms of a generalized hyperreactivity to novel or stressful stimuli.

Responses of Four Rice Varieties to Elevated CO2 and Different Salinity Levels

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Sheidollah Kazemi

2018-05-01

Full Text Available Abstract:: This study was carried out in 2014 at Isfahan University of Technology, Iran, to evaluate the responses of four rice varieties (Neda, Deylamani, Shiroudi and Domsorkh to ambient (360 ± 50 μmol/mol and elevated (700 ± 50 μmol/mol air carbon dioxide (CO2 concentrations under four salinity levels (0, 30, 60 and 90 mmol/L NaCl. There was significant variation among rice varieties in response to elevated CO2 concentration under the four salinity levels. Under non-saline condition, elevated CO2 increased the dry weight of Neda, Deylamani and Domsorkh by 8%, 50% and 8%, respectively, but reversely decreased that of Shiroudi by 34%. Increasing CO2 concentration significantly reduced the negative effects of salinity on Shiroudi, but these effects were even increased in Deylamani and Domsorkh under all the salinity levels and in Neda only under 30 and 60 mmol/L NaCl. Significant correlations were established between plant dry weight, SPAD value and leaf area under both CO2 levels. However, this trend was observed only at ambient CO2 concentration in the presence of soluble carbohydrates. The results revealed the genotype and salinity dependence of the effects of CO2 concentrations on the rice traits investigated. Key words: CO2 concentration, genetic diversity, salt tolerance, water soluble carbohydrate

Co-Ingestion of Rice Bran Soymilk or Plain Soymilk with White Bread: Effects on the Glycemic and Insulinemic Response.

Science.gov (United States)

Camps, Stefan Gerardus; Lim, Joseph; Ishikado, Atsushi; Inaba, Yumi; Suwa, Makoto; Matsumoto, Motonobu; Henry, Christiani Jeyakumar

2018-04-04

The regular consumption of soy products is associated with inverse incidence of type 2 diabetes, and there has been an increasing interest in the glycemia reducing potential of rice bran and its components. In this study, we investigated whether consuming soymilk with the addition of rice bran (fiber) can reduce the glycemic response of a carbohydrate meal. Seventeen healthy Asian men (BMI: 18.5-29 kg/m²) participated in this randomized crossover trial. On four occasions, they consumed white bread (two times) and white bread with two different soymilks differing in protein and rice bran content. Blood samples were taken to measure glucose and insulin response over a period of 3 hours. Taking the glycemic index (GI) value of white bread as a reference value of 100, the GI of white bread when co-ingested with rice bran soymilk (RBS) was 83.1 (±7.7) and sugar-free soymilk (SFS) was 77.5 (±10.1), both were lower than white bread ( p 0.05). The glucose/insulin ratio of RBS and SFS were respectively 43.1 (± 6.1) and 60.0 (± 17.0) and were lower ( p < 0.05) than white bread (123.5 ± 21.1) during the first 30 min. In conclusion, co-ingestion of low amounts of soy protein with a carbohydrate meal stimulated early-phase insulin secretion and thereby increased blood glucose clearance effectiveness. Furthermore, rice bran-fortified soymilk reduced the glycemic response similarly to soymilk with a greater dose of soy protein. Rice bran and its components offer therapeutic potential for glycemic and insulinemic control.

A Benzothiadiazole Primes Parsley Cells for Augmented Elicitation of Defense Responses

Science.gov (United States)

Katz, Vera A.; Thulke, Oliver U.; Conrath, Uwe

1998-01-01

Systemic acquired resistance is an important component of the disease-resistance arsenal of plants, and is associated with an enhanced potency for activating local defense responses upon pathogen attack. Here we demonstrate that pretreatment with benzothiadiazole (BTH), a synthetic activator of acquired resistance in plants, augmented the sensitivity for low-dose elicitation of coumarin phytoalexin secretion by cultured parsley (Petroselinum crispum L.) cells. Enhanced coumarin secretion was associated with potentiated activation of genes encoding Phe ammonia-lyase (PAL). The augmentation of PAL gene induction was proportional to the length of pretreatment with BTH, indicating time-dependent priming of the cells. In contrast to the PAL genes, those for anionic peroxidase were directly induced by BTH in the absence of elicitor, thus confirming a dual role for BTH in the activation of plant defenses. Strikingly, the ability of various chemicals to enhance plant disease resistance correlated with their capability to potentiate parsley PAL gene elicitation, emphasizing an important role for defense response potentiation in acquired plant disease resistance. PMID:9701589

Responses of endogenous proline in rice seedlings under chromium exposure

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X.Z. Yu

2016-12-01

Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p

Response of rice genotypes to weed competition in dry direct-seeded rice in India.

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Mahajan, Gulshan; Ramesha, Mugalodi S; Chauhan, Bhagirath S

2014-01-01

The differential weed-competitive abilities of eight rice genotypes and the traits that may confer such attributes were investigated under partial weedy and weed-free conditions in naturally occurring weed flora in dry direct-seeded rice during the rainy seasons of 2011 and 2012 at Ludhiana, Punjab, India. The results showed genotypic differences in competitiveness against weeds. In weed-free plots, grain yield varied from 6.6 to 8.9 t ha(-1) across different genotypes; it was lowest for PR-115 and highest for the hybrid H-97158. In partial weedy plots, grain yield and weed biomass at flowering varied from 3.6 to 6.7 t ha(-1) and from 174 to 419 g m(-2), respectively. In partial weedy plots, grain yield was lowest for PR-115 and highest for PR-120. Average yield loss due to weed competition ranged from 21 to 46% in different rice genotypes. The study showed that early canopy closure, high leaf area index at early stage, and high root biomass and volume correlated positively with competitiveness. This study suggests that some traits (root biomass, leaf area index, and shoot biomass at the early stage) could play an important role in conferring weed competitiveness and these traits can be explored for dry-seeded rice.

Priming of antiherbivore defensive responses in plants

Institute of Scientific and Technical Information of China (English)

Jinwon Kim; Gary W.Felton

2013-01-01

Defense priming is defined as increased readiness of defense induction.A growing body of literature indicates that plants (or intact parts of a plant) are primed in anticipation of impending environmental stresses,both biotic and abiotic,and upon the following stimulus,induce defenses more quickly and strongly.For instance,some plants previously exposed to herbivore-inducible plant volatiles (HIPVs) from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding.Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently,but significant advances were made in the past three years,including non-HIPV-mediated defense priming,epigenetic modifications as the molecular mechanism of priming,and others.It is timely to consider the advances in research on defense priming in the plantinsect interactions.

Characterization of rice black-streaked dwarf virus- and rice stripe virus-derived siRNAs in singly and doubly infected insect vector Laodelphax striatellus.

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Junmin Li

Full Text Available Replication of RNA viruses in insect cells triggers an antiviral defense that is mediated by RNA interference (RNAi which generates viral-derived small interfering RNAs (siRNAs. However, it is not known whether an antiviral RNAi response is also induced in insects by reoviruses, whose double-stranded RNA genome replication is thought to occur within core particles. Deep sequencing of small RNAs showed that when the small brown planthopper (Laodelphax striatellus was infected by Rice black-streaked dwarf virus (RBSDV (Reoviridae; Fijivirus, more viral-derived siRNAs accumulated than when the vector insect was infected by Rice stripe virus (RSV, a negative single-stranded RNA virus. RBSDV siRNAs were predominantly 21 and 22 nucleotides long and there were almost equal numbers of positive and negative sense. RBSDV siRNAs were frequently generated from hotspots in the 5'- and 3'-terminal regions of viral genome segments but these hotspots were not associated with any predicted RNA secondary structures. Under laboratory condition, L. striatellus can be infected simultaneously with RBSDV and RSV. Double infection enhanced the accumulation of particular genome segments but not viral coat protein of RBSDV and correlated with an increase in the abundance of siRNAs derived from RBSDV. The results of this study suggest that reovirus replication in its insect vector potentially induces an RNAi-mediated antiviral response.

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

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

2015-04-01

Cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. The activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ARA), and DNA fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. Microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and shoot tissues. Among the six cyanobacterial strains employed, Calothrix sp. (RPC1), Anabaena laxa (RPAN8), and Anabaena azollae (C16) were the best performing strains, in terms of colonization in roots and stem. These strains also enhanced nitrogen fixation and stimulated the activity of plant defense/cell wall-degrading enzymes. A significantly high correlation was also recorded between the elicited plant enzymes, growth, and ARA. DNA fingerprinting using highly iterated palindromic sequences (HIP-TG) further helped in proving the establishment of inoculated organisms in the roots/shoots of rice plants. This study illustrated that the colonization of cyanobacteria in the plant tissues is facilitated by increased elicitation of plant enzymes, leading to improved plant growth, nutrient mobilization, and enhanced plant fitness. Such strains can be promising candidates for developing "cyanobacteria colonized-nitrogen-fixing rice plants" in the future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Genome-wide analysis of ABA-responsive elements ABRE and CE3 reveals divergent patterns in Arabidopsis and rice

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Riaño-Pachón Diego

2007-08-01

Full Text Available Abstract Background In plants, complex regulatory mechanisms are at the core of physiological and developmental processes. The phytohormone abscisic acid (ABA is involved in the regulation of various such processes, including stomatal closure, seed and bud dormancy, and physiological responses to cold, drought and salinity stress. The underlying tissue or plant-wide control circuits often include combinatorial gene regulatory mechanisms and networks that we are only beginning to unravel with the help of new molecular tools. The increasing availability of genomic sequences and gene expression data enables us to dissect ABA regulatory mechanisms at the individual gene expression level. In this paper we used an in-silico-based approach directed towards genome-wide prediction and identification of specific features of ABA-responsive elements. In particular we analysed the genome-wide occurrence and positional arrangements of two well-described ABA-responsive cis-regulatory elements (CREs, ABRE and CE3, in thale cress (Arabidopsis thaliana and rice (Oryza sativa. Results Our results show that Arabidopsis and rice use the ABA-responsive elements ABRE and CE3 distinctively. Earlier reports for various monocots have identified CE3 as a coupling element (CE associated with ABRE. Surprisingly, we found that while ABRE is equally abundant in both species, CE3 is practically absent in Arabidopsis. ABRE-ABRE pairs are common in both genomes, suggesting that these can form functional ABA-responsive complexes (ABRCs in Arabidopsis and rice. Furthermore, we detected distinct combinations, orientation patterns and DNA strand preferences of ABRE and CE3 motifs in rice gene promoters. Conclusion Our computational analyses revealed distinct recruitment patterns of ABA-responsive CREs in upstream sequences of Arabidopsis and rice. The apparent absence of CE3s in Arabidopsis suggests that another CE pairs with ABRE to establish a functional ABRC capable of

Genome-wide analysis of ABA-responsive elements ABRE and CE3 reveals divergent patterns in Arabidopsis and rice.

Science.gov (United States)

Gómez-Porras, Judith L; Riaño-Pachón, Diego Mauricio; Dreyer, Ingo; Mayer, Jorge E; Mueller-Roeber, Bernd

2007-08-01

In plants, complex regulatory mechanisms are at the core of physiological and developmental processes. The phytohormone abscisic acid (ABA) is involved in the regulation of various such processes, including stomatal closure, seed and bud dormancy, and physiological responses to cold, drought and salinity stress. The underlying tissue or plant-wide control circuits often include combinatorial gene regulatory mechanisms and networks that we are only beginning to unravel with the help of new molecular tools. The increasing availability of genomic sequences and gene expression data enables us to dissect ABA regulatory mechanisms at the individual gene expression level. In this paper we used an in-silico-based approach directed towards genome-wide prediction and identification of specific features of ABA-responsive elements. In particular we analysed the genome-wide occurrence and positional arrangements of two well-described ABA-responsive cis-regulatory elements (CREs), ABRE and CE3, in thale cress (Arabidopsis thaliana) and rice (Oryza sativa). Our results show that Arabidopsis and rice use the ABA-responsive elements ABRE and CE3 distinctively. Earlier reports for various monocots have identified CE3 as a coupling element (CE) associated with ABRE. Surprisingly, we found that while ABRE is equally abundant in both species, CE3 is practically absent in Arabidopsis. ABRE-ABRE pairs are common in both genomes, suggesting that these can form functional ABA-responsive complexes (ABRCs) in Arabidopsis and rice. Furthermore, we detected distinct combinations, orientation patterns and DNA strand preferences of ABRE and CE3 motifs in rice gene promoters. Our computational analyses revealed distinct recruitment patterns of ABA-responsive CREs in upstream sequences of Arabidopsis and rice. The apparent absence of CE3s in Arabidopsis suggests that another CE pairs with ABRE to establish a functional ABRC capable of interacting with transcription factors. Further studies will be

Responses of wheat and rice to factorial combinations of ambient and elevated CO

NARCIS (Netherlands)

Cai, Chuang; Yin, Xinyou; He, Shuaiqi; Jiang, Wenyu; Si, Chuanfei; Struik, Paul C.; Luo, Weihong; Li, Gang; Xie, Yingtian; Xiong, Yan; Pan, Genxing

2016-01-01

Elevated CO₂ and temperature strongly affect crop production, but understanding of the crop response to combined CO₂ and temperature increases under field conditions is still limited while data are scarce. We grew wheat (Triticum aestivum L.) and rice (Oryza sativa L.) under

PAMP-induced defense responses in potato require both salicylic acid and jasmonic acid.

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Halim, Vincentius A; Altmann, Simone; Ellinger, Dorothea; Eschen-Lippold, Lennart; Miersch, Otto; Scheel, Dierk; Rosahl, Sabine

2009-01-01

To elucidate the molecular mechanisms underlying pathogen-associated molecular pattern (PAMP)-induced defense responses in potato (Solanum tuberosum), the role of the signaling compounds salicylic acid (SA) and jasmonic acid (JA) was analyzed. Pep-13, a PAMP from Phytophthora, induces the accumulation of SA, JA and hydrogen peroxide, as well as the activation of defense genes and hypersensitive-like cell death. We have previously shown that SA is required for Pep-13-induced defense responses. To assess the importance of JA, RNA interference constructs targeted at the JA biosynthetic genes, allene oxide cyclase and 12-oxophytodienoic acid reductase, were expressed in transgenic potato plants. In addition, expression of the F-box protein COI1 was reduced by RNA interference. Plants expressing the RNA interference constructs failed to accumulate the respective transcripts in response to wounding or Pep-13 treatment, neither did they contain significant amounts of JA after elicitation. In response to infiltration of Pep-13, the transgenic plants exhibited a highly reduced accumulation of reactive oxygen species as well as reduced hypersensitive cell death. The ability of the JA-deficient plants to accumulate SA suggests that SA accumulation is independent or upstream of JA accumulation. These data show that PAMP responses in potato require both SA and JA and that, in contrast to Arabidopsis, these compounds act in the same signal transduction pathway. Despite their inability to fully respond to PAMP treatment, the transgenic RNA interference plants are not altered in their basal defense against Phytophthora infestans.

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 ...

Understanding the immune system architecture and transcriptome responses to southern rice black-streaked dwarf virus in Sogatella furcifera.

Science.gov (United States)

Wang, Lin; Tang, Nan; Gao, Xinlei; Guo, Dongyang; Chang, Zhaoxia; Fu, Yating; Akinyemi, Ibukun A; Wu, Qingfa

2016-11-02

Sogatella furcifera, the white-backed planthopper (WBPH), has become one of the most destructive pests in rice production owing to its plant sap-sucking behavior and efficient transmission of Southern rice black-streaked dwarf virus (SRBSDV) in a circulative, propagative and persistent manner. The dynamic and complex SRBSDV-WBPH-rice plant interaction is still poorly understood. In this study, based on a homology-based genome-wide analysis, 348 immune-related genes belonging to 28 families were identified in WBPH. A transcriptome analysis of non-viruliferous (NVF) and viruliferous groups with high viral titers (HVT) and median viral titers (MVT) revealed that feeding on SRBSDV-infected rice plants has a significant impact on gene expression, regardless of viral titers in insects. We identified 278 up-regulated and 406 down-regulated genes shared among the NVF, MVT, and HVT groups and detected significant down-regulation of primary metabolism-related genes and oxidoreductase. In viruliferous WBPH with viral titer-specific transcriptome changes, 1,906 and 1,467 genes exhibited strict monotonically increasing and decreasing expression, respectively. The RNAi pathway was the major antiviral response to increasing viral titers among diverse immune responses. These results clarify the responses of immune genes and the transcriptome of WBPH to SRBSDV and improve our knowledge of the functional relationship between pathogen, vector, and host.

Rice ethylene-response AP2/ERF factor OsEATB restricts internode elongation by down-regulating a gibberellin biosynthetic gene.

Science.gov (United States)

Qi, Weiwei; Sun, Fan; Wang, Qianjie; Chen, Mingluan; Huang, Yunqing; Feng, Yu-Qi; Luo, Xiaojin; Yang, Jinshui

2011-09-01

Plant height is a decisive factor in plant architecture. Rice (Oryza sativa) plants have the potential for rapid internodal elongation, which determines plant height. A large body of physiological research has shown that ethylene and gibberellin are involved in this process. The APETALA2 (AP2)/Ethylene-Responsive Element Binding Factor (ERF) family of transcriptional factors is only present in the plant kingdom. This family has various developmental and physiological functions. A rice AP2/ERF gene, OsEATB (for ERF protein associated with tillering and panicle branching) was cloned from indica rice variety 9311. Bioinformatic analysis suggested that this ERF has a potential new function. Ectopic expression of OsEATB showed that the cross talk between ethylene and gibberellin, which is mediated by OsEATB, might underlie differences in rice internode elongation. Analyses of gene expression demonstrated that OsEATB restricts ethylene-induced enhancement of gibberellin responsiveness during the internode elongation process by down-regulating the gibberellin biosynthetic gene, ent-kaurene synthase A. Plant height is negatively correlated with tiller number, and higher yields are typically obtained from dwarf crops. OsEATB reduces rice plant height and panicle length at maturity, promoting the branching potential of both tillers and spikelets. These are useful traits for breeding high-yielding crops.

Effect of an extruded pea or rice diet on postprandial insulin and cardiovascular responses in dogs.

Science.gov (United States)

Adolphe, J L; Drew, M D; Silver, T I; Fouhse, J; Childs, H; Weber, L P

2015-08-01

Peas are increasing in popularity as a source of carbohydrate, protein and fibre in extruded canine diets. The aim of this study was to test the health effects of two canine diets with identical macronutrient profiles, but containing either yellow field peas or white rice as the carbohydrate source on metabolism, cardiovascular outcomes and adiposity. First, the acute glycemic, insulinemic and cardiovascular responses to the pea- or rice-based diets were determined in normal weight beagles (n = 7 dogs). The glycemic index did not differ between the pea diet (56 ± 12) and rice diet (63 ± 9). Next, obese beagles (n = 9) were fed the yellow field pea diet or white rice diet ad libitum for 12 weeks in a crossover study. Adiposity (measured using computed tomography), metabolic (oral glucose tolerance test, plasma leptin, adiponectin, C-reactive protein) and cardiovascular assessments (echocardiography and blood pressure) were performed before and after each crossover study period. After 12 weeks on each diet, peak insulin (p = 0.05) and area under the curve (AUC) for insulin after a 10 g oral glucose tolerance test (p = 0.05) were lower with the pea than the rice diet. Diet did not show a significant effect on body weight, fat distribution, cardiovascular variables, adiponectin or leptin. In conclusion, a diet containing yellow field peas reduced the postprandial insulin response after glucose challenge in dogs despite continued obesity, indicating improved metabolic health. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Spatiotemporal heterogeneity of tomato induced defense responses affects spider mite performance and behavior.

Science.gov (United States)

Schimmel, Bernardus C J; Ataide, Livia M S; Kant, Merijn R

2017-10-03

When feeding from tomato (Solanum lycopersicum), the generalist spider mite Tetranychus urticae induces jasmonate (JA)- and salicylate (SA)-regulated defense responses that hamper its performance. The related T. evansi, a Solanaceae-specialist, suppresses these defenses, thereby upholding a high performance. On a shared leaf, T. urticae can be facilitated by T. evansi, likely via suppression of defenses by the latter. Yet, when infesting the same plant, T. evansi outcompetes T. urticae. Recently, we found that T. evansi intensifies suppression of defenses locally, i.e., at its feeding site, after T. urticae mites were introduced onto adjacent leaf tissue. This hyper-suppression is paralleled by an increased oviposition rate of T. evansi, probably promoting its competitive population growth. Here we present additional data that not only provide insight into the spatiotemporal dynamics of defense induction and suppression by mites, but that also suggest T. evansi to manipulate more than JA and SA defenses alone.

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...

Manganese-induced cadmium stress tolerance in rice seedlings: Coordinated action of antioxidant defense, glyoxalase system and nutrient homeostasis.

Science.gov (United States)

Rahman, Anisur; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

The accumulation of cadmium (Cd) alters different physiological and biochemical attributes that affect plant growth and yield. In our study, we investigated the regulatory role of supplemental manganese (Mn) on hydroponically grown rice (Oryza sativa L. cv. BRRI dhan29) seedlings under Cd-stress conditions. Exposure of 14-d-old seedlings to 0.3mM CdCl 2 for three days caused growth inhibition, chlorosis, nutrient imbalance, and higher Cd accumulation. Higher Cd uptake caused oxidative stress through lipid peroxidation, loss of plasma membrane integrity, and overproduction of reactive oxygen species (ROS) and methylglyoxal (MG). The exogenous application of 0.3mM MnSO 4 to Cd-treated seedlings partly recovered Cd-induced water loss, chlorosis, growth inhibition, and nutrient imbalance by reducing Cd uptake and its further translocation to the upper part of the plant. Supplemental Mn also reduced Cd-induced oxidative damage and lipid peroxidation by improved antioxidant defense and glyoxalase systems through enhancing ROS and MG detoxification, respectively. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

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

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.

Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

KAUST Repository

Yun, Kil-Young; Park, Myoung Ryoul; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Mauleon, Ramil; Wijaya, Edward; Bajic, Vladimir B.; Bruskiewich, Richard; de los Reyes, Benildo G

2010-01-01

-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress

[Response of soil hydrolase and oxidoreductase activities to free-air carbon dioxide enrichment (FACE) under rice-wheat rotation].

Science.gov (United States)

Zhang, Yulan; Zhang, Lili; Chen, Lijun; Wu, Zhijie

2004-06-01

This paper studied the response of soil urease, phosphatase, arylsulphatase and dehydrogenase to 200 micromol x mol(-1) CO2 elevation under rice-wheat rotation. The results showed that under CO2 elevation, the urease activity in 0-10 cm soil layer was decreased at the early growth stages of wheat but increased at its booting stage; the activity increased at the early growth stages of rice but decreased at its ripening stage. Phosphatase activity was increased during the whole growth period of wheat; the activity increased at the tillering stage of rice but decreased at its later growth stages. Arylsulphatase activity was decreased at the over-wintering and booting stages of wheat but increased at its tillering and ripening stages. Dehydrogenase activity was decreased at the early growth stages of wheat and rice, but increased at their late growth stages.

Isolation of a novel PP2C gene from rice and its response to abiotic ...

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... versely affect plant growth and crop production (Duan et al., 2009; Xiong et al., ... events, growth fac- tors responses, hormone and environmental stimuli res- ... Rice cold, heat and water-deficit treatment. For the drought tests ...

Data set from a comprehensive phosphoproteomic analysis of rice variety IRBB5 in response to bacterial blight

Directory of Open Access Journals (Sweden)

Yuxuan Hou

2016-03-01

Full Text Available Bacterial blight (BB caused by Xanthomonas oryzae pv. oryzae (Xoo has become one of the most devastating diseases for rice, a major food source for over half of the world populations. To investigate the roles of protein phosphorylation in rice bacterial blight resistance, a quantitative phosphoproteomic study was conducted in rice variety IRBB5 at 0 h and 24 h after Xoo infection. 2367 and 2223 phosphosites on 1334 and 1297 representative proteins were identified in 0 h and 24 h after Xoo infection, respectively, out of which 762 proteins were found to be differentially phosphorylated. In associated with the published article “A comprehensive quantitative phosphoproteome analysis of rice in response to bacterial blight” in BMC Plant Biology (Hou et al., 2015 [1], this dataset article provided the detailed information of experimental designing, methods, features as well as the raw data of mass spectrometry (MS identification. The MS proteomics data could be fully accessed from the ProteomeXchange Consortium with the dataset identifier http://www.ebi.ac.uk/pride/archive/projects/PXD002222. Keywords: Rice (Oryza sativa L., Bacterial blight, Phosphoproteome

Response to Competitive Entry: A Rationale for Delayed Defensive Reaction

OpenAIRE

Ajay Kalra; Surendra Rajiv; Kannan Srinivasan

1998-01-01

Empirical studies examining responses to new product entries come to the puzzling conclusion that, in general, an incumbent reacts to a new entrant after a significant delay. Even easy-to-implement price cuts are observed after significant lag following entry. These findings seem to contradict the existing literature that either implicitly assumes or strongly advocates immediate defensive responses to limit competitive encroachment. When a competing firm enters the market, consumers may be un...

Role of salicylic acid in alleviating oxidative damage in rice roots (Oryza sativa) subjected to cadmium stress

International Nuclear Information System (INIS)

Guo, B.; Liang, Y.C.; Zhu, Y.G.; Zhao, F.J.

2007-01-01

Time-dependent changes in enzymatic and non-enzymatic antioxidants, and lipid peroxidation were investigated in roots of rice (Oryza sativa) grown hydroponically with Cd, with or without pretreatment of salicylic acid (SA). Exposure to 50 μM Cd significantly decreased root growth, and activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), but increased the concentrations of H 2 O 2 , malondialdehyde (MDA), ascorbic acid (AsA), glutathione (GSH) and non-protein thiols (NPT). However, pretreatment with 10 μM SA enhanced the activities of antioxidant enzymes and the concentrations of non-enzymatic antioxidants, but lowered the concentrations of H 2 O 2 and MDA in the Cd-stressed rice compared with the Cd treatment alone. Pretreatment with SA alleviated the Cd-induced inhibition of root growth. The results showed that pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. The possible mechanism of SA-induced H 2 O 2 signaling in mediating Cd tolerance was discussed. - Pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance

Overexpression of a Pathogenesis-Related Protein 10 Enhances Biotic and Abiotic Stress Tolerance in Rice

Directory of Open Access Journals (Sweden)

Jingni Wu

2016-12-01

Full Text Available Pathogenesis-related proteins play multiple roles in plant development and biotic and abiotic stress tolerance. Here, we characterize a rice defense related gene named “jasmonic acid inducible pathogenesis-related class 10” (JIOsPR10 to gain an insight into its functional properties. Semi-quantitative RT-PCR analysis showed up-regulation of JIOsPR10 under salt and drought stress conditions. Constitutive over-expression JIOsPR10 in rice promoted shoot and root development in transgenic plants, however, their productivity was unaltered. Further experiments exhibited that the transgenic plants showed reduced susceptibility to rice blast fungus, and enhanced salt and drought stress tolerance as compared to the wild type. A comparative proteomic profiling of wild type and transgenic plants showed that overexpression of JIOsPR10 led to the differential modulation of several proteins mainly related with oxidative stresses, carbohydrate metabolism, and plant defense. Taken together, our findings suggest that JIOsPR10 plays important roles in biotic and abiotic stresses tolerance probably by activation of stress related proteins.

Rice hypersensitive induced reaction protein 1 (OsHIR1) associates with plasma membrane and triggers hypersensitive cell death.

Science.gov (United States)

Zhou, Liang; Cheung, Ming-Yan; Li, Man-Wah; Fu, Yaping; Sun, Zongxiu; Sun, Sai-Ming; Lam, Hon-Ming

2010-12-30

In plants, HIR (Hypersensitive Induced Reaction) proteins, members of the PID (Proliferation, Ion and Death) superfamily, have been shown to play a part in the development of spontaneous hypersensitive response lesions in leaves, in reaction to pathogen attacks. The levels of HIR proteins were shown to correlate with localized host cell deaths and defense responses in maize and barley. However, not much was known about the HIR proteins in rice. Since rice is an important cereal crop consumed by more than 50% of the populations in Asia and Africa, it is crucial to understand the mechanisms of disease responses in this plant. We previously identified the rice HIR1 (OsHIR1) as an interacting partner of the OsLRR1 (rice Leucine-Rich Repeat protein 1). Here we show that OsHIR1 triggers hypersensitive cell death and its localization to the plasma membrane is enhanced by OsLRR1. Through electron microscopy studies using wild type rice plants, OsHIR1 was found to mainly localize to the plasma membrane, with a minor portion localized to the tonoplast. Moreover, the plasma membrane localization of OsHIR1 was enhanced in transgenic rice plants overexpressing its interacting protein partner, OsLRR1. Co-localization of OsHIR1 and OsLRR1 to the plasma membrane was confirmed by double-labeling electron microscopy. Pathogen inoculation studies using transgenic Arabidopsis thaliana expressing either OsHIR1 or OsLRR1 showed that both transgenic lines exhibited increased resistance toward the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. However, OsHIR1 transgenic plants produced more extensive spontaneous hypersensitive response lesions and contained lower titers of the invading pathogen, when compared to OsLRR1 transgenic plants. The OsHIR1 protein is mainly localized to the plasma membrane, and its subcellular localization in that compartment is enhanced by OsLRR1. The expression of OsHIR1 may sensitize the plant so that it is more prone to HR and hence can react more

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

Degree of habitual mastication seems to contribute to interindividual variations in the glycemic response to rice but not to spaghetti.

Science.gov (United States)

Ranawana, Viren; Henry, C Jeya K; Pratt, Megan

2010-06-01

Previous work by our group showed that the degree of particle breakdown of rice during mastication affects in vitro glycemic potency. The objective of this study was to confirm these in vitro findings in an in vivo model. We hypothesized that the degree of habitual mastication will influence individuals' in vivo blood glucose response (glycemic response, or GR) to carbohydrate foods. Eleven participants came in on six nonconsecutive days to the laboratory and evaluated 2 test foods (rice and spaghetti). Their GR was measured for the subsequent 120 minutes. Mastication parameters were determined using surface electrode electromyography. The particle size distribution of individuals' masticated food was also determined. The intraindividual number of chews per mouthful did not significantly differ for rice and spaghetti (29.9 and 33, respectively), although masticated particle size distribution did (P mastication and the GR were observed for rice, but none for spaghetti. Individuals' peak GR (at 45 minutes) correlated significantly with the particles size distribution of their masticated rice (P = .002), and also with the total incremental area under the curve for the GR (r = -0.72; P = .012) and the incremental area under the curve for the first 45 (r = -0.74; P = .010) and 60 minutes (r = 0.73; P = .010) postconsumption. The results suggest that individual differences in mastication may be one of the causes for interindividual differences in the GR to rice but not spaghetti. Copyright 2010 Elsevier Inc. All rights reserved.

Allelic variants of OsSUB1A cause differential expression of transcription factor genes in response to submergence in rice.

Science.gov (United States)

Sharma, Niharika; Dang, Trang Minh; Singh, Namrata; Ruzicic, Slobodan; Mueller-Roeber, Bernd; Baumann, Ute; Heuer, Sigrid

2018-01-08

Flooding during seasonal monsoons affects millions of hectares of rice-cultivated areas across Asia. Submerged rice plants die within a week due to lack of oxygen, light and excessive elongation growth to escape the water. Submergence tolerance was first reported in an aus-type rice landrace, FR13A, and the ethylene-responsive transcription factor (TF) gene SUB1A-1 was identified as the major tolerance gene. Intolerant rice varieties generally lack the SUB1A gene but some intermediate tolerant varieties, such as IR64, carry the allelic variant SUB1A-2. Differential effects of the two alleles have so far not been addressed. As a first step, we have therefore quantified and compared the expression of nearly 2500 rice TF genes between IR64 and its derived tolerant near isogenic line IR64-Sub1, which carries the SUB1A-1 allele. Gene expression was studied in internodes, where the main difference in expression between the two alleles was previously shown. Nineteen and twenty-six TF genes were identified that responded to submergence in IR64 and IR64-Sub1, respectively. Only one gene was found to be submergence-responsive in both, suggesting different regulatory pathways under submergence in the two genotypes. These differentially expressed genes (DEGs) mainly included MYB, NAC, TIFY and Zn-finger TFs, and most genes were downregulated upon submergence. In IR64, but not in IR64-Sub1, SUB1B and SUB1C, which are also present in the Sub1 locus, were identified as submergence responsive. Four TFs were not submergence responsive but exhibited constitutive, genotype-specific differential expression. Most of the identified submergence responsive DEGs are associated with regulatory hormonal pathways, i.e. gibberellins (GA), abscisic acid (ABA), and jasmonic acid (JA), apart from ethylene. An in-silico promoter analysis of the two genotypes revealed the presence of allele-specific single nucleotide polymorphisms, giving rise to ABRE, DRE/CRT, CARE and Site II cis-elements, which

Econometric Model of Rice Policy Based On Presidential Instruction

Science.gov (United States)

Abadi Sembiring, Surya; Hutauruk, Julia

2018-01-01

The objective of research is to build an econometric model based on Presidential Instruction rice policy. The data was monthly time series from March 2005 to September 2009. Rice policy model specification using simultaneous equation, consisting of 14 structural equations and four identity equation, which was estimated using Two Stages Least Squares (2SLS) method. The results show that: (1) an increase of government purchasing price of dried harvest paddy has a positive impact on to increase in total rice production and community rice stock, (2) an increase community rice stock lead to decrease the rice imports, (3) an increase of the realization of the distribution of subsidized ZA fertilizers and the realization of the distribution of subsidized NPK fertilizers has a positive impact on to increase in total rice production and community rice stock and to reduce rice imports, (4) the price of the dried harvest paddy is highly responsive to the water content of dried harvest paddy both the short run and long run, (5) the quantity of rice imported is highly responsive to the imported rice price, both short run and long run.

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

Science.gov (United States)

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

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

Elongator Plays a Positive Role in Exogenous NAD-Induced Defense Responses in Arabidopsis.

Science.gov (United States)

An, Chuanfu; Ding, Yezhang; Zhang, Xudong; Wang, Chenggang; Mou, Zhonglin

2016-05-01

Extracellular NAD is emerging as an important signal molecule in animal cells, but its role in plants has not been well-established. Although it has been shown that exogenous NAD(+) activates defense responses in Arabidopsis, components in the exogenous NAD(+)-activated defense pathway remain to be fully discovered. In a genetic screen for mutants insensitive to exogenous NAD(+) (ien), we isolated a mutant named ien2. Map-based cloning revealed that IEN2 encodes ELONGATA3 (ELO3)/AtELP3, a subunit of the Arabidopsis Elongator complex, which functions in multiple biological processes, including histone modification, DNA (de)methylation, and transfer RNA modification. Mutations in the ELO3/AtELP3 gene compromise exogenous NAD(+)-induced expression of pathogenesis-related (PR) genes and resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326, and transgenic expression of the coding region of ELO3/AtELP3 in elo3/Atelp3 restores NAD(+) responsiveness to the mutant plants, demonstrating that ELO3/AtELP3 is required for exogenous NAD(+)-induced defense responses. Furthermore, mutations in genes encoding the other five Arabidopsis Elongator subunits (ELO2/AtELP1, AtELP2, ELO1/AtELP4, AtELP5, and AtELP6) also compromise exogenous NAD(+)-induced PR gene expression and resistance to P. syringae pv. maculicola ES4326. These results indicate that the Elongator complex functions as a whole in exogenous NAD(+)-activated defense signaling in Arabidopsis.

Mental imagery affects subsequent automatic defense responses

Directory of Open Access Journals (Sweden)

Muriel A Hagenaars

2015-06-01

Full Text Available Automatic defense responses promote survival and appropriate action under threat. They have also been associated with the development of threat-related psychiatric syndromes. Targeting such automatic responses during threat may be useful in populations with frequent threat exposure. Here, two experiments explored whether mental imagery as a pre-trauma manipulation could influence fear bradycardia (a core characteristic of freezing during subsequent analogue trauma (affective picture viewing. Image-based interventions have proven successful in the treatment of threat-related disorders, and are easily applicable. In Experiment 1 43 healthy participants were randomly assigned to an imagery script condition. Participants executed a passive viewing task with blocks of neutral, pleasant and unpleasant pictures after listening to an auditory script that was either related (with a positive or a negative outcome or unrelated to the unpleasant pictures from the passive viewing task. Heart rate was assessed during script listening and during passive viewing. Imagining negative related scripts resulted in greater bradycardia (neutral-unpleasant contrast than imagining positive scripts, especially unrelated. This effect was replicated in Experiment 2 (N = 51, again in the neutral-unpleasant contrast. An extra no-script condition showed that bradycardia was not induced by the negative related script, but rather that a positive script attenuated bradycardia. These preliminary results might indicate reduced vigilance after unrelated positive events. Future research should replicate these findings using a larger sample. Either way, the findings show that highly automatic defense behavior can be influenced by relatively simple mental imagery manipulations.

The Polycistronic miR166k-166h Positively Regulates Rice Immunity via Post-transcriptional Control of EIN2

Directory of Open Access Journals (Sweden)

Raquel Salvador-Guirao

2018-03-01

Full Text Available MicroRNAs (miRNAs are small RNAs acting as regulators of gene expression at the post-transcriptional level. In plants, most miRNAs are generated from independent transcriptional units, and only a few polycistronic miRNAs have been described. miR166 is a conserved miRNA in plants targeting the HD-ZIP III transcription factor genes. Here, we show that a polycistronic miRNA comprising two miR166 family members, miR166k and miR166h, functions as a positive regulator of rice immunity. Rice plants with activated MIR166k-166h expression showed enhanced resistance to infection by the fungal pathogens Magnaporthe oryzae and Fusarium fujikuroi, the causal agents of the rice blast and bakanae disease, respectively. Disease resistance in rice plants with activated MIR166k-166h expression was associated with a stronger expression of defense responses during pathogen infection. Stronger induction of MIR166k-166h expression occurred in resistant but not susceptible rice cultivars. Notably, the ethylene-insensitive 2 (EIN2 gene was identified as a novel target gene for miR166k. The regulatory role of the miR166h-166k polycistron on the newly identified target gene results from the activity of the miR166k-5p specie generated from the miR166k-166h precursor. Collectively, our findings support a role for miR166k-5p in rice immunity by controlling EIN2 expression. Because rice blast is one of the most destructive diseases of cultivated rice worldwide, unraveling miR166k-166h-mediated mechanisms underlying blast resistance could ultimately help in designing appropriate strategies for rice protection.

Transcriptome analysis of phosphorus stress responsiveness in the seedlings of Dongxiang wild rice (Oryza rufipogon Griff.).

Science.gov (United States)

Deng, Qian-Wen; Luo, Xiang-Dong; Chen, Ya-Ling; Zhou, Yi; Zhang, Fan-Tao; Hu, Biao-Lin; Xie, Jian-Kun

2018-03-15

Low phosphorus availability is a major factor restricting rice growth. Dongxiang wild rice (Oryza rufipogon Griff.) has many useful genes lacking in cultivated rice, including stress resistance to phosphorus deficiency, cold, salt and drought, which is considered to be a precious germplasm resource for rice breeding. However, the molecular mechanism of regulation of phosphorus deficiency tolerance is not clear. In this study, cDNA libraries were constructed from the leaf and root tissues of phosphorus stressed and untreated Dongxiang wild rice seedlings, and transcriptome sequencing was performed with the goal of elucidating the molecular mechanisms involved in phosphorus stress response. The results indicated that 1184 transcripts were differentially expressed in the leaves (323 up-regulated and 861 down-regulated) and 986 transcripts were differentially expressed in the roots (756 up-regulated and 230 down-regulated). 43 genes were up-regulated both in leaves and roots, 38 genes were up-regulated in roots but down-regulated in leaves, and only 2 genes were down-regulated in roots but up-regulated in leaves. Among these differentially expressed genes, the detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in phosphorus deficiency tolerance. Meanwhile, the differentially expressed genes were also annotated with gene ontology terms and key pathways via functional classification and Kyoto Encyclopedia of Gene and Genomes pathway mapping, respectively. A set of the most important candidate genes was then identified by combining the differentially expressed genes found in the present study with previously identified phosphorus deficiency tolerance quantitative trait loci. The present work provides abundant genomic information for functional dissection of the phosphorus deficiency resistance of Dongxiang wild rice, which will be help to understand the biological regulatory mechanisms of phosphorus

Effects of internal and external factors on the budgeting between defensive and non-defensive responses in Aplysia.

Science.gov (United States)

Leod, Kaitlyn A Mac; Seas, Alexandra; Wainwright, Marcy L; Mozzachiodi, Riccardo

2018-04-25

Following exposure to aversive stimuli, organisms budget their behaviors by augmenting defensive responses and reducing/suppressing non-defensive behaviors. This budgeting process must be flexible to accommodate modifications in the animal's internal and/or external state that require the normal balance between defensive and non-defensive behaviors to be adjusted. When exposed to aversive stimuli, the mollusk Aplysia budgets its behaviors by concurrently enhancing defensive withdrawal reflexes (an elementary form of learning known as sensitization) and suppressing feeding. Sensitization and feeding suppression are consistently co-expressed following different training protocols and share common temporal domains, suggesting that they are interlocked. In this study, we attempted to uncouple the co-expression of sensitization and feeding suppression using: 1) manipulation of the animal's motivational state through prolonged food deprivation and 2) extended training with aversive stimuli that induces sensitization lasting for weeks. Both manipulations uncoupled the co-expression of the above behavioral changes. Prolonged food deprivation prevented the expression of sensitization, but not of feeding suppression. Following the extended training, sensitization and feeding suppression were co-expressed only for a limited time (i.e., 24 h), after which feeding returned to baseline levels as sensitization persisted for up to seven days. These findings indicate that sensitization and feeding suppression are not interlocked and that their co-expression can be uncoupled by internal (prolonged food deprivation) and external (extended aversive training) factors. The different strategies, by which the co-expression of sensitization and feeding suppression was altered, provide an example of how budgeting strategies triggered by an identical aversive experience can vary depending on the state of the organism. Copyright © 2018 Elsevier B.V. All rights reserved.

Radiation from Radioactive Cesium (137 Cs) and Strontium (90Sr) Contaminated soil during the Chernobyl Nuclear Disaster Triggers Rice Immune Response

International Nuclear Information System (INIS)

Kimura, S.; Rakwal, R.; Agrawal, G. K.; Tamogami, S.; Kim, Y.H.; Shibato, J.; Sahoo, S. K.; Shiraishi, K.; Los, I. P.; Shevachuk, V. E.; Yonekura, M.; Iwahashi, H.

2004-01-01

After the Chernobyl nuclear accident in 1986 that exposed most of the population of the Northern hemisphere to various degrees of radiation, the public's perception of nuclear risk was completely changed. other than the obvious and much studied health impact, the agriculture and environmental impacts still pose a serious problem. Cesium-137, which has a half-life of 30.1 years, is the most important radionuclide left from Chernobyl's catastrophic explosion, and is present at high concentrations (activity, gamma-and beta-emitter) in the 0-5 cm soil layer. Strontium-90 (beta.emitter), which has a half-life of 29.1 years also constitutes a problem for plants. The effect of these radionuclides, and importantly show the radiation released therein affects plants has not been investigated in detail. In this study, we tested the hypothesis that leaves of two-week-old rice (japonica-type c, Nipponbare) seedlings (that constitutes a well-established in-vitro assay system) would respond to radiation (from the contaminated soil from Masany. Belarus, with major radionuclides, 137 Cs and 90 sr) by inducing various biochemical/molecular changes associated with the defense/stress response, including those involving mechanisms affecting the inactivation of damaging reactive oxygen specie. Rice (oryza sativa L.) is an enormously important food and monocot cereal crop research model whose draft genome sequence has recently been released. A molecular (northern analysis which provides a picture of the transcriptional changes of a particular gene), proteomics (two-dimensional electrophoresis (2-DE) is a powerful tool in understanding which proteins are present in particular tissue under given condition), and metabolomic (determining the metabolic profiles of metabolites induced during stress) approach was employed to monitor the changes in defense(stress-related (D/S-.r) genes, proteins (using 2-DE coupled with amino acid sequencing and immunoblotting) and metabolites (in particular

Divergent Responses of the Diazotrophic Microbiome to Elevated CO2 in Two Rice Cultivars

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Yongjie Yu

2018-06-01

Full Text Available The species-specific responses of plant growth to elevated atmospheric CO2 concentration (eCO2 could lead to N limitation and potentially influence the sustainability of ecosystem. Questions remain unanswered with regards to the response of soil N2-fixing community to eCO2 when developing high-yielding agroecosystem to dampen the future rate of increase in CO2 levels and associated climate warming. This study demonstrates the divergent eCO2 influences on the paddy diazotrophic community between weak- and strong-responsive rice cultivars. In response to eCO2, the diazotrophic abundance increased more for the strong-responsive cultivar treatments than for the weak-responsive ones. Only the strong-responsive cultivars decreased the alpha diversity and separated the composition of diazotrophic communities in response to eCO2. The topological indices of the ecological networks further highlighted the different co-occurrence patterns of the diazotrophic microbiome in rice cultivars under eCO2. Strong-responsive cultivars destabilized the diazotrophic community by complicating and centralizing the co-occurrence network as well as by shifting the hub species from Bradyrhizobium to Dechloromonas in response to eCO2. On the contrary, the network pattern of the weak-responsive cultivars was simplified and decentralized in response to eCO2, with the hub species shifting from Halorhodospira under aCO2 to Sideroxydans under eCO2. Collectively, the above information indicates that the strong-responsive cultivars could potentially undermine the belowground ecosystem from the diazotrophs perspective in response to eCO2. This information highlights that more attention should be paid to the stability of the belowground ecosystem when developing agricultural strategies to adapt prospective climatic scenarios by growing high-yielding crop cultivars under eCO2.

Responses of upland rice to fertilizer

International Nuclear Information System (INIS)

Nashriyah Mat; Abdul Khalik Wood; Khairuddin Abdul Rahim; Zaini Hamzah

1996-01-01

The concentration and uptake of macro nutrients, micro nutrients and toxic elements were compared to dry matter yield, biomass components and primary and secondary tillering. Plant tissue analysis of N, P, K, Ca, Mg, Cl, Fe, Mn, Na, Ca, Al, Cr, As, Th and Ce were carried out using chemical and neutron activation analysis. N and K were found to accumulate in the green vegetative biomass whereas P, Ca, Mg, Fe and Zn were bound in the dead-plus-senesced component. Compared to control, urea fertilization increased the dry matter yield and uptakes of N, P, Ca, Mg, Fe, Mn, Na, Al, Th and Ce by upland rice. In addition to similar increases; cattle manuring also increased the green vegetative biomass, secondary tillering and uptake of K, Cl, Co, Cr and As. With the exception of Th uptake, upland rice Oryza Sativa var. Seri Pelanduk subjected to cattle manuring responded better to the uptake of various elements and produced more secondary tillers

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

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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.

Variation in plant defense against invasive herbivores: evidence for a hypersensitive response in eastern hemlocks (Tsuga canadensis).

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Radville, Laura; Chaves, Arielle; Preisser, Evan L

2011-06-01

Herbivores can trigger a wide array of morphological and chemical changes in their host plants. Feeding by some insects induces a defensive hypersensitive response, a defense mechanism consisting of elevated H(2)O(2) levels and tissue death at the site of herbivore feeding. The invasive hemlock woolly adelgid Adelges tsugae ('HWA') and elongate hemlock scale Fiorinia externa ('EHS') feed on eastern hemlocks; although both are sessile sap feeders, HWA causes more damage than EHS. The rapid rate of tree death following HWA infestation has led to the suggestion that feeding induces a hypersensitive response in hemlock trees. We assessed the potential for an herbivore-induced hypersensitive response in eastern hemlocks by measuring H(2)O(2) levels in foliage from HWA-infested, EHS-infested, and uninfested trees. Needles with settled HWA or EHS had higher H(2)O(2) levels than control needles, suggesting a localized hypersensitive plant response. Needles with no direct contact to settled HWA also had high H(2)O(2) levels, suggesting that HWA infestation may induce a systemic defense response in eastern hemlocks. There was no similar systemic defensive response in the EHS treatment. Our results showed that two herbivores in the same feeding guild had dramatically different outcomes on the health of their shared host.

The response of rice (Oryza sativa L. to elevated night temperature with application of Pyraclostobin

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T.Y. Wahjanto

2016-07-01

Full Text Available Rice productivity is having a problem related with climate change phenomenon, mainly the global warming. The rising of temperature in some country threat the rice production. The increasing of temperature is a major limiting factor that affects yield through the growth and development of rice plant. This study was aimed to examine the response of rice (Oryza sativa L. to elevated night temperature with the application of Pyraclostobin. A glasshouse experiment that was conducted from March to August 2015 at Brawijaya University Research Station of Jatikerto – Malang, used nested plot design with three replications and two treatments. The first treatments were the night temperature level (normal temperature, increased 2oC, and increased 4oC. The second treatments were the concentration of Pyraclostrobin (0 ppm, 400 ppm and 800 ppm. Results of the study showed that the increase of temperature at night for about 2oC and 4oC, as well as application of Pyraclostrobin, affected growth and yield of rice. Application of Pyraclostrobin by concentrations of 400 ppm and 800 ppm effectively reduced yield loss by increasing night temperature of 2oC, which resulted in 20.20% and 24.93%, respectively, in comparison with the control; while the increase of night temperature by 4oC have resulted 26.86% and 33.33% in comparison with the control. Pyraclostrobin was effective in maintaining percentage of the filled spikelets by the increase of temperature at night for about 2oC and 4oC.

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

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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.

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

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

2015-01-01

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

Modulation of ethylene responses by OsRTH1 overexpression reveals the biological significance of ethylene in rice seedling growth and development

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Zhang, Wei; Zhou, Xin; Wen, Chi-Kuang

2012-01-01

Overexpression of Arabidopsis Reversion-To-ethylene Sensitivity1 (RTE1) results in whole-plant ethylene insensitivity dependent on the ethylene receptor gene Ethylene Response1 (ETR1). However, overexpression of the tomato RTE1 homologue Green Ripe (GR) delays fruit ripening but does not confer whole-plant ethylene insensitivity. It was decided to investigate whether aspects of ethylene-induced growth and development of the monocotyledonous model plant rice could be modulated by rice RTE1 homologues (OsRTH genes). Results from a cross-species complementation test in Arabidopsis showed that OsRTH1 overexpression complemented the rte1-2 loss-of-function mutation and conferred whole-plant ethylene insensitivity in an ETR1-dependent manner. In contrast, OsRTH2 and OsRTH3 overexpression did not complement rte1-2 or confer ethylene insensitivity. In rice, OsRTH1 overexpression substantially prevented ethylene-induced alterations in growth and development, including leaf senescence, seedling leaf elongation and development, coleoptile elongation or curvature, and adventitious root development. Results of subcellular localizations of OsRTHs, each fused with the green fluorescent protein, in onion epidermal cells suggested that the three OsRTHs were predominantly localized to the Golgi. OsRTH1 may be an RTE1 orthologue of rice and modulate rice ethylene responses. The possible roles of auxins and gibberellins in the ethylene-induced alterations in growth were evaluated and the biological significance of ethylene in the early stage of rice seedling growth is discussed. PMID:22451723

MicroRNA regulated defense responses in Triticum aestivum L. during Puccinia graminis f.sp. tritici infection.

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Gupta, Om Prakash; Permar, Vipin; Koundal, Vikas; Singh, Uday Dhari; Praveen, Shelly

2012-02-01

Plants have evolved diverse mechanism to recognize pathogen attack and triggers defense responses. These defense responses alter host cellular function regulated by endogenous, small, non-coding miRNAs. To understand the mechanism of miRNAs regulated cellular functions during stem rust infection in wheat, we investigated eight different miRNAs viz. miR159, miR164, miR167, miR171, miR444, miR408, miR1129 and miR1138, involved in three different independent cellular defense response to infection. The investigation reveals that at the initiation of disease, accumulation of miRNAs might be playing a key role in hypersensitive response (HR) from host, which diminishes at the maturation stage. This suggests a possible host-fungal synergistic relation leading to susceptibility. Differential expression of these miRNAs in presence and absence of R gene provides a probable explanation of miRNA regulated R gene mediated independent pathways.

Responses of rice to salinity and exogenous glycinebetaine by using positron emitting tracer imaging system

International Nuclear Information System (INIS)

Le Xuan Tham; Vo Huy Dang; Noriko, S.

2002-01-01

Effect of salinity stress (NaCl) and glycinebetaine on typical non-halophyte plants - rice (Oryza sativa L.) was examined for the growth, net photosynthesis and transpiration functions of seedlings. Using 22 Na, the inhibition of net uptake and translocation of sodium of seedlings stressed at 0.15% NaCl in solution and previously treated with exogenous glycinebetaine was observed by positron-emitting tracer imaging system, namely PETIS for diagnosis of early responses of plants to salt stress. Effects of exogenous glycinebetaine on rice plants stressed with salinity via osmotic protection and particularly stabilization of membrane permeability to inhibit Na uptake and translocation were discussed in connection with promising potentials of PETIS for researches on plants. (Author)

Nitrogen Supply Influences Herbivore-Induced Direct and Indirect Defenses and Transcriptional Responses in Nicotiana attenuata[w

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Lou, Yonggen; Baldwin, Ian T.

2004-01-01

Although nitrogen (N) availability is known to alter constitutive resistance against herbivores, its influence on herbivore-induced responses, including signaling pathways, transcriptional signatures, and the subsequently elicited chemical defenses is poorly understood. We used the native tobacco, Nicotiana attenuata, which germinates in the postfire environment and copes with large changes in soil N during postfire succession, to compare a suite of Manduca sexta- and elicitor-induced responses in plants grown under high- and low-N (LN) supply rates. LN supply decreased relative growth rates and biomass by 35% at 40 d compared to high-N plants; furthermore, it also attenuated (by 39 and 60%) the elicitor-induced jasmonate and salicylate bursts, two N-intensive direct defenses (nicotine and trypsin proteinase inhibitors, albeit by different mechanisms), and carbon-containing nonvolatile defenses (rutin, chlorogenic acid, and diterpene glycosides), but did not affect the induced release of volatiles (cis-α-bergamotene and germacrene A), which function as indirect defenses. M. sexta and methyl jasmonate-induced transcriptional responses measured with a microarray enriched in herbivore-induced genes were also substantially reduced in plants grown under LN supply rates. In M. sexta-attacked LN plants, only 36 (45%) up-regulated and 46 (58%) down-regulated genes showed the same regulation as those in attacked high-N plants. However, transcriptional responses frequently directly countered the observed metabolic changes. Changes in a leaf's sensitivity to elicitation, an attacked leaf's waning ability to export oxylipin wound signals, and/or resource limitations in LN plants can account for the observed results, underscoring the conclusion that defense activation is a resource-intensive response. PMID:15133153

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.

The Tyrosine Aminomutase TAM1 Is Required for β-Tyrosine Biosynthesis in Rice

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Yan, Jian; Aboshi, Takako; Teraishi, Masayoshi; Strickler, Susan R.; Spindel, Jennifer E.; Tung, Chih-Wei; Takata, Ryo; Matsumoto, Fuka; Maesaka, Yoshihiro; McCouch, Susan R.; Okumoto, Yutaka; Mori, Naoki; Jander, Georg

2015-01-01

Non-protein amino acids, often isomers of the standard 20 protein amino acids, have defense-related functions in many plant species. A targeted search for jasmonate-induced metabolites in cultivated rice (Oryza sativa) identified (R)-β-tyrosine, an isomer of the common amino acid (S)-α-tyrosine in the seeds, leaves, roots, and root exudates of the Nipponbare cultivar. Assays with 119 diverse cultivars showed a distinct presence/absence polymorphism, with β-tyrosine being most prevalent in temperate japonica cultivars. Genetic mapping identified a candidate gene on chromosome 12, which was confirmed to encode a tyrosine aminomutase (TAM1) by transient expression in Nicotiana benthamiana and in vitro enzyme assays. A point mutation in TAM1 eliminated β-tyrosine production in Nipponbare. Rice cultivars that do not produce β-tyrosine have a chromosome 12 deletion that encompasses TAM1. Although β-tyrosine accumulation was induced by the plant defense signaling molecule jasmonic acid, bioassays with hemipteran and lepidopteran herbivores showed no negative effects at physiologically relevant β-tyrosine concentrations. In contrast, root growth of Arabidopsis thaliana and other tested dicot plants was inhibited by concentrations as low as 1 μM. As β-tyrosine is exuded into hydroponic medium at higher concentrations, it may contribute to the allelopathic potential of rice. PMID:25901084

Melatonin modulates the fetal cardiovascular defense response to acute hypoxia.

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Thakor, Avnesh S; Allison, Beth J; Niu, Youguo; Botting, Kimberley J; Serón-Ferré, Maria; Herrera, Emilio A; Giussani, Dino A

2015-08-01

Experimental studies in animal models supporting protective effects on the fetus of melatonin in adverse pregnancy have prompted clinical trials in human pregnancy complicated by fetal growth restriction. However, the effects of melatonin on the fetal defense to acute hypoxia, such as that which may occur during labor, remain unknown. This translational study tested the hypothesis, in vivo, that melatonin modulates the fetal cardiometabolic defense responses to acute hypoxia in chronically instrumented late gestation fetal sheep via alterations in fetal nitric oxide (NO) bioavailability. Under anesthesia, 6 fetal sheep at 0.85 gestation were instrumented with vascular catheters and a Transonic flow probe around a femoral artery. Five days later, fetuses were exposed to acute hypoxia with or without melatonin treatment. Fetal blood was taken to determine blood gas and metabolic status and plasma catecholamine concentrations. Hypoxia during melatonin treatment was repeated during in vivo NO blockade with the NO clamp. This technique permits blockade of de novo synthesis of NO while compensating for the tonic production of the gas, thereby maintaining basal cardiovascular function. Melatonin suppressed the redistribution of blood flow away from peripheral circulations and the glycemic and plasma catecholamine responses to acute hypoxia. These are important components of the fetal brain sparing response to acute hypoxia. The effects of melatonin involved NO-dependent mechanisms as the responses were reverted by fetal treatment with the NO clamp. Melatonin modulates the in vivo fetal cardiometabolic responses to acute hypoxia by increasing NO bioavailability. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evidence for divergence of response in Indica, Japonica, and wild rice to high CO2 x temperature interaction

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Previous studies suggest that the intraspecific variability of rice yield response to rising carbon dioxide concentration, [CO2], could serve as a basis of selection to improve genotypes for future high CO2 conditions. However, assessment of responses to elevated [CO2] must consider air temperature,...

Genome-Wide Transcriptome Analysis of Cadmium Stress in Rice

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Youko Oono

2016-01-01

Full Text Available Rice growth is severely affected by toxic concentrations of the nonessential heavy metal cadmium (Cd. To elucidate the molecular basis of the response to Cd stress, we performed mRNA sequencing of rice following our previous study on exposure to high concentrations of Cd (Oono et al., 2014. In this study, rice plants were hydroponically treated with low concentrations of Cd and approximately 211 million sequence reads were mapped onto the IRGSP-1.0 reference rice genome sequence. Many genes, including some identified under high Cd concentration exposure in our previous study, were found to be responsive to low Cd exposure, with an average of about 11,000 transcripts from each condition. However, genes expressed constitutively across the developmental course responded only slightly to low Cd concentrations, in contrast to their clear response to high Cd concentration, which causes fatal damage to rice seedlings according to phenotypic changes. The expression of metal ion transporter genes tended to correlate with Cd concentration, suggesting the potential of the RNA-Seq strategy to reveal novel Cd-responsive transporters by analyzing gene expression under different Cd concentrations. This study could help to develop novel strategies for improving tolerance to Cd exposure in rice and other cereal crops.

Rice Snl6, a cinnamoyl-CoA reductase-like gene family member, is required for NH1-mediated immunity to Xanthomonas oryzae pv. oryzae.

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Rebecca S Bart

2010-09-01

Full Text Available Rice NH1 (NPR1 homolog 1 is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo, constitutive expression of defense related genes and enhanced benzothiadiazole (BTH- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development.

Response of rice to nitrogenous fertilizer and irradiated sewage sludge

International Nuclear Information System (INIS)

Azam, F.; Lodhi, A.; Sajjad, M.H.

2003-01-01

A greenhouse pot experiment was conducted to study the effect of Gamma-irradiated sewage sludge, applied alone or along with /sup 15/N-labelled ammonium sulphate (1.0 atom % /sup 15/N excess), on rice yield and N uptake. Six-kg portions of a clay loam were amended wit sewage sludge to obtain N addition rates of 30, 60, 90 and 120 mg kg/sub -1/ soil. In other treatments nitrogen was applied at 120 mg kg/sup -1/ as /sup 15/N-labelled ammonium sulphate or 120 mg kg/sub -1/ as /sup 15/NH/sub 4/-N + sludge-N in the ratios of 1:3, 1:1, or 3:1. All the treatments were given before transplanting rice. Three healthy seedlings (4-week old) of rice (Oryza sativa L., var. Bas-Pak) were transplanted pot/sup -1/ and the plants harvested at maturity. Application of sewage sludge caused a significant improvement in rice yield. Grain yield increased by 188% at sludge-N of 120 mg N kg/sup -1/. The yield benefit at similar rate of fertilizer N was 304%, the increase being more at higher rates of application. The increase in rice yield was dependent on uptake of N and sewage sludge significantly improved the availability of N to the plants. The additional plant N in sludge treated soil was partially attributable to enhanced mineralization of soil N and N/sub 2/ fixation by free living microorganisms. Application of inorganic N led to a significant increase in the availability of N to plants from soil organic matter and sewage sludge. Results of combined application suggested that substantial savings of fertilizer N can be made by using sewage sludge on rice-fields. (author)

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)

Physcomitrella patens Activates Defense Responses against the Pathogen Colletotrichum gloeosporioides

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Guillermo Reboledo

2015-09-01

Full Text Available The moss Physcomitrella patens is a suitable model plant to analyze the activation of defense mechanisms after pathogen assault. In this study, we show that Colletotrichum gloeosporioides isolated from symptomatic citrus fruit infects P. patens and cause disease symptoms evidenced by browning and maceration of tissues. After C. gloeosporioides infection, P. patens reinforces the cell wall by the incorporation of phenolic compounds and induces the expression of a Dirigent-protein-like encoding gene that could lead to the formation of lignin-like polymers. C. gloeosporioides-inoculated protonemal cells show cytoplasmic collapse, browning of chloroplasts and modifications of the cell wall. Chloroplasts relocate in cells of infected tissues toward the initially infected C. gloeosporioides cells. P. patens also induces the expression of the defense genes PAL and CHS after fungal colonization. P. patens reporter lines harboring the auxin-inducible promoter from soybean (GmGH3 fused to β-glucuronidase revealed an auxin response in protonemal tissues, cauloids and leaves of C. gloeosporioides-infected moss tissues, indicating the activation of auxin signaling. Thus, P. patens is an interesting plant to gain insight into defense mechanisms that have evolved in primitive land plants to cope with microbial pathogens.

The Chamber for Studying Rice Response to Elevated Nighttime Temperature in Field

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Song Chen

2013-01-01

Full Text Available An in situ temperature-controlled field chamber was developed for studying a large population of rice plant under different nighttime temperature treatments while maintaining conditions similar to those in the field during daytime. The system consists of a pipe hoop shed-type chamber with manually removable covers manipulated to provide a natural environment at daytime and a relatively stable and accurate temperature at night. Average air temperatures of 22.4 ± 0.3°C at setting of 22°C, 27.6 ± 0.4°C at 27°C, and 23.8 ± 0.7°C ambient conditions were maintained with the system. No significant horizontal and vertical differences in temperature were found and only slight changes in water temperatures were observed between the chambers and ambient conditions at 36 days after transplanting. A slight variation in CO2 concentration was observed at the end of the treatment during the day, but the 10-μmol CO2 mol−1 difference was too small to alter plant response. The present utilitarian system, which only utilizes an air conditioner/heater, is suitable for studying the effect of nighttime temperature on plant physiological responses with minimal perturbation of other environmental factors. At the same time, it will enable in situ screening of many rice genotypes.

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

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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.

Lead (Pb) Toxicity; Physio-Biochemical Mechanisms, Grain Yield, Quality, and Pb Distribution Proportions in Scented Rice.

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Ashraf, Umair; Kanu, Adam S; Deng, Quanquan; Mo, Zhaowen; Pan, Shenggang; Tian, Hua; Tang, Xiangru

2017-01-01

Lead (Pb) caused interruptions with normal plant metabolism, crop yield losses and quality issues are of great concern. This study assessed the physio-biochemical responses, yield and grain quality traits and Pb distribution proportions in three different fragrant rice cultivars i.e., Meixiangzhan-2, Xinagyaxiangzhan and Basmati-385. Plants were exposed to 400, 800, and 1,200 ppm of Pb while pots without Pb were taken as control (0 ppm). Our results showed that Pb toxicity significantly ( P production of hydrogen peroxide (H 2 O 2 ), malanodialdehyde (MDA) and leaves leachates; while such effects were more apparent in Xinagyaxiangzhan than other two rice cultivars. Pb stress differentially affected the production protein, proline and soluble sugars; however the production rates were higher at heading stage (HS) than maturity stage (MS). Furthermore, Pb stress altered superoxide dismutase (SOD), peroxidases (POD), catalases (CAT) and ascorbate peroxidases (APX) activities and glutathione (GSH) and oxidized glutathione (GSSG) production in all rice cultivars at both HS and MS. All Pb levels reduced the yield and yield components of all rice cultivars; nonetheless such reductions were observed highest in Xinagyaxiangzhan (69.12%) than Meixiangzhan-2 (58.05%) and Basmati-385 (46.27%) and resulted in grain quality deterioration. Significant and positive correlations among rice yields with productive tillers/pot and grains per panicle while negative with sterility percentage were also observed. In addition, all rice cultivars readily taken up the Pb contents from soil to roots and transported upward in different proportions with maximum in roots followed by stemss, leaves, ears and grains. Higher proportions of Pb contents in above ground plant parts in Xinagyaxiangzhan possibly lead to maximum losses in this cultivar than other two cultivars; while less damage in Basmati-385 might be related to strong anti-oxidative defense system and lower proportions of Pb contents in

Rice Ethylene-Response AP2/ERF Factor OsEATB Restricts Internode Elongation by Down-Regulating a Gibberellin Biosynthetic Gene1[W][OA

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Qi, Weiwei; Sun, Fan; Wang, Qianjie; Chen, Mingluan; Huang, Yunqing; Feng, Yu-Qi; Luo, Xiaojin; Yang, Jinshui

2011-01-01

Plant height is a decisive factor in plant architecture. Rice (Oryza sativa) plants have the potential for rapid internodal elongation, which determines plant height. A large body of physiological research has shown that ethylene and gibberellin are involved in this process. The APETALA2 (AP2)/Ethylene-Responsive Element Binding Factor (ERF) family of transcriptional factors is only present in the plant kingdom. This family has various developmental and physiological functions. A rice AP2/ERF gene, OsEATB (for ERF protein associated with tillering and panicle branching) was cloned from indica rice variety 9311. Bioinformatic analysis suggested that this ERF has a potential new function. Ectopic expression of OsEATB showed that the cross talk between ethylene and gibberellin, which is mediated by OsEATB, might underlie differences in rice internode elongation. Analyses of gene expression demonstrated that OsEATB restricts ethylene-induced enhancement of gibberellin responsiveness during the internode elongation process by down-regulating the gibberellin biosynthetic gene, ent-kaurene synthase A. Plant height is negatively correlated with tiller number, and higher yields are typically obtained from dwarf crops. OsEATB reduces rice plant height and panicle length at maturity, promoting the branching potential of both tillers and spikelets. These are useful traits for breeding high-yielding crops. PMID:21753115

Early changes in shoot transcriptome of rice in response to Rhodotorula mucilaginosa JGTA-S1

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Chinmay Saha

2015-12-01

Full Text Available Yeasts of Rhodotorula genus have been reported to show endophytic colonization in different plants. Some of the Rhodotorula species are found to exhibit plant growth promoting activities and also have been reported to protect plants against invading pathogens. A yeast strain closely related to Rhodotorula mucilaginosa was isolated from the endosphere of Typha angustifolia collected from a Uranium mine. A microarray analysis was performed to investigate the early changes in rice shoot transcripts in response to this yeast (R. mucilaginosa JGTA-S1. Transcriptional changes were monitored in 6 h and 24 h treated rice plant shoots as compared to 0 h control. The microarray data has been submitted to the NCBI GEO repository under the accession number of GSE64321.

Hydraulic properties of rice and the response of gas exchange to water stress.

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Stiller, Volker; Lafitte, H Renee; Sperry, John S

2003-07-01

We investigated the role of xylem cavitation, plant hydraulic conductance, and root pressure in the response of rice (Oryza sativa) gas exchange to water stress. In the field (Philippines), the percentage loss of xylem conductivity (PLC) from cavitation exceeded 60% in leaves even in watered controls. The PLC versus leaf water potential relationship indicated diurnal refilling of cavitated xylem. The leaf water potential causing 50 PLC (P(50)) was -1.6 MPa and did not differ between upland versus lowland rice varieties. Greenhouse-grown varieties (Utah) were more resistant to cavitation with a 50 PLC of -1.9 MPa but also showed no difference between varieties. Six-day droughts caused concomitant reductions in leaf-specific photosynthetic rate, leaf diffusive conductance, and soil-leaf hydraulic conductance that were associated with cavitation-inducing water potentials and the disappearance of nightly root pressure. The return of root pressure after drought was associated with the complete recovery of leaf diffusive conductance, leaf-specific photosynthetic rate, and soil-leaf hydraulic conductance. Root pressure after the 6-d drought (61.2 +/- 8.8 kPa) was stimulated 7-fold compared with well-watered plants before drought (8.5 +/- 3.8 kPa). The results indicate: (a) that xylem cavitation plays a major role in the reduction of plant hydraulic conductance during drought, and (b) that rice can readily reverse cavitation, possibly aided by nocturnal root pressure.

Rice field for the treatment of pond aquaculture effluents | Wang ...

African Journals Online (AJOL)

We conducted an experiment to evaluate the efficiency of rice fields in treating pond aquaculture effluent and its responses to different fertilizer treatments. Four treatments was considered in the experiment: no rice planted as the control (CT); rice planted and no fertilizer input (RE); rice planted and a rate of approximately ...

Integrating Soil Silicon Amendment into Management Programs for Insect Pests of Drill-Seeded Rice.

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Villegas, James M; Way, Michael O; Pearson, Rebecca A; Stout, Michael J

2017-08-13

Silicon soil amendment has been shown to enhance plant defenses against insect pests. Rice is a silicon-accumulating graminaceous plant. In the southern United States, the rice water weevil and stem borers are important pests of rice. Current management tactics for these pests rely heavily on the use of insecticides. This study evaluated the effects of silicon amendment when combined with current management tactics for these rice insect pests in the field. Field experiments were conducted from 2013 to 2015. Rice was drill-planted in plots subjected to factorial combinations of variety (conventional and hybrid), chlorantraniliprole seed treatment (treated and untreated), and silicon amendment (treated and untreated). Silicon amendment reduced densities of weevil larvae on a single sampling date in 2014, but did not affect densities of whiteheads caused by stem borers. In contrast, insecticidal seed treatment strongly reduced densities of both weevil larvae and whiteheads. Higher densities of weevil larvae were also observed in the hybrid variety in 2014, while higher incidences of whiteheads were observed in the conventional variety in 2014 and 2015. Silicon amendment improved rice yields, as did chlorantraniliprole seed treatment and use of the hybrid variety.

Full establishment of arbuscular mycorrhizal symbiosis in rice occurs independently of enzymatic jasmonate biosynthesis.

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Caroline Gutjahr

Full Text Available Development of the mutualistic arbuscular mycorrhiza (AM symbiosis between most land plants and fungi of the Glomeromycota is regulated by phytohormones. The role of jasmonate (JA in AM colonization has been investigated in the dicotyledons Medicago truncatula, tomato and Nicotiana attenuata and contradicting results have been obtained with respect to a neutral, promotive or inhibitory effect of JA on AM colonization. Furthermore, it is currently unknown whether JA plays a role in AM colonization of monocotyledonous roots. Therefore we examined whether JA biosynthesis is required for AM colonization of the monocot rice. To this end we employed the rice mutant constitutive photomorphogenesis 2 (cpm2, which is deficient in JA biosynthesis. Through a time course experiment the amount and morphology of fungal colonization did not differ between wild-type and cpm2 roots. Furthermore, no significant difference in the expression of AM marker genes was detected between wild type and cpm2. However, treatment of wild-type roots with 50 μM JA lead to a decrease of AM colonization and this was correlated with induction of the defense gene PR4. These results indicate that JA is not required for AM colonization of rice but high levels of JA in the roots suppress AM development likely through the induction of defense.

The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

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Gopaljee Jha

2009-01-01

Full Text Available Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

Rice epigenomics and epigenetics: challenges and opportunities.

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Chen, Xiangsong; Zhou, Dao-Xiu

2013-05-01

During recent years rice genome-wide epigenomic information such as DNA methylation and histone modifications, which are important for genome activity has been accumulated. The function of a number of rice epigenetic regulators has been studied, many of which are found to be involved in a diverse range of developmental and stress-responsive pathways. Analysis of epigenetic variations among different rice varieties indicates that epigenetic modification may lead to inheritable phenotypic variation. Characterizing phenotypic consequences of rice epigenomic variations and the underlining chromatin mechanism and identifying epialleles related to important agronomic traits may provide novel strategies to enhance agronomically favorable traits and grain productivity in rice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Plant methyl salicylate induces defense responses in the rhizobacterium Bacillus subtilis.

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Kobayashi, Kazuo

2015-04-01

Bacillus subtilis is a rhizobacterium that promotes plant growth and health. Cultivation of B. subtilis with an uprooted weed on solid medium produced pleat-like architectures on colonies near the plant. To test whether plants emit signals that affect B. subtilis colony morphology, we examined the effect of plant-related compounds on colony morphology. Bacillus subtilis formed mucoid colonies specifically in response to methyl salicylate, which is a plant-defense signal released in response to pathogen infection. Methyl salicylate induced mucoid colony formation by stimulating poly-γ-glutamic acid biosynthesis, which formed enclosing capsules that protected the cells from exposure to antimicrobial compounds. Poly-γ-glutamic acid synthesis depended on the DegS-DegU two-component regulatory system, which activated DegSU-dependent gene transcription in response to methyl salicylate. Bacillus subtilis did not induce plant methyl salicylate production, indicating that the most probable source of methyl salicylate in the rhizosphere is pathogen-infected plants. Methyl salicylate induced B. subtilis biosynthesis of the antibiotics bacilysin and fengycin, the latter of which exhibited inhibitory activity against the plant pathogenic fungus Fusarium oxysporum. We propose that B. subtilis may sense plants under pathogen attack via methyl salicylate, and express defense responses that protect both B. subtilis and host plants in the rhizosphere. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Response of nitrogen-fixing water fern Azolla biofertilization to rice crop.

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Bhuvaneshwari, K; Singh, Pawan Kumar

2015-08-01

The water fern Azolla harbors nitrogen-fixing cyanobacterium Anabaena azollae as symbiont in its dorsal leaves and is known as potent N 2 fixer. Present investigation was carried out to study the influence of fresh Azolla when used as basal incorporation in soil and as dual cropped with rice variety Mahsoori separately and together with and without chemical nitrogen fertilizer in pots kept under net house conditions. Results showed that use of Azolla as basal or dual or basal plus dual influenced the rice crop positively where use of fern as basal plus dual was superior and served the nitrogen requirement of rice. There was marked increase in plant height, number of effective tillers, dry mass and nitrogen content of rice plants with the use of Azolla and N-fertilizers alone and other combinations. The use of Azolla also increased organic matter and potassium contents of the soil.

Synthesis of low-cost adsorbent from rice bran for the removal of reactive dye based on the response surface methodology

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Hong, Gui-Bing; Wang, Yi-Kai

2017-11-01

Rice bran is a major by-product of the rice milling industry and is abundant in Taiwan. This study proposed a simple method for modifying rice bran to make it a low-cost adsorbent to remove reactive blue 4 (RB4) from aqueous solutions. The effects of independent variables such as dye concentration (100-500 ppm), adsorbent dosage (20-120 mg) and temperature (30-60 °C) on the dye adsorption capacity of the modified rice bran adsorbent were investigated by using the response surface methodology (RSM). The results showed that the dye maximum adsorption capacity of the modified rice bran adsorbent was 151.3 mg g-1 with respect to a dye concentration of 500 ppm, adsorbent dosage of 65.36 mg, and temperature of 60 °C. The adsorption kinetics data followed the pseudo-second-order kinetic model, and the isotherm data fit the Langmuir isotherm model well. The maximum monolayer adsorption capacity was 178.57-185.19 mg g-1, which was comparable to that of other agricultural waste adsorbents used to remove RB4 from aqueous solutions in the literature. The thermodynamics analysis results indicated that the adsorption of RB4 onto the modified rice bran adsorbent is an endothermic, spontaneous monolayer adsorption that occurs through a physical process.

Composition and Fatty Acid Profile of Goat Meat Sausages with Added Rice Bran

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Fatemeh Malekian

2014-01-01

Full Text Available A scientific consensus on the relationship between obesity, obesity related diseases, and diet has emerged. One of the factors is overconsumption of the red meats such as pork and beef. Goat meat has the potential to replace these traditionally consumed meats. Rice bran is a rich source of antioxidants such as vitamin E. In this study, goat meat sausages were formulated to contain 0, 1.5 or 3 percent stabilized rice bran. Proximate and fatty acid composition, α-tocopherol, cholesterol concentration, and antioxidant activities of cooked goat meat sausages containing varying percentages of rice bran were measured. Data were analyzed using a fixed effects model. The fat percentage in the goat meat sausages increased in response to increasing rice bran percentages (P<0.001. Saturated fatty acids concentration decreased linearly (P<0.01, while unsaturated fatty acids and omega-3 and omega-6 fatty acids increased linearly in response to increasing rice bran percentages (P<0.05. The concentration of α-tocopherol in sausages increased linearly in response to increasing rice bran percentages (P<0.01. Also, antioxidant activity increased linearly in sausages in response to added rice bran (P<0.01. The cholesterol concentration of sausages did not vary significantly in response to added rice bran.

Composition and Fatty Acid Profile of Goat Meat Sausages with Added Rice Bran.

Science.gov (United States)

Malekian, Fatemeh; Khachaturyan, Margarita; Gebrelul, Sebhatu; Henson, James F

2014-01-01

A scientific consensus on the relationship between obesity, obesity related diseases, and diet has emerged. One of the factors is overconsumption of the red meats such as pork and beef. Goat meat has the potential to replace these traditionally consumed meats. Rice bran is a rich source of antioxidants such as vitamin E. In this study, goat meat sausages were formulated to contain 0, 1.5 or 3 percent stabilized rice bran. Proximate and fatty acid composition, α-tocopherol, cholesterol concentration, and antioxidant activities of cooked goat meat sausages containing varying percentages of rice bran were measured. Data were analyzed using a fixed effects model. The fat percentage in the goat meat sausages increased in response to increasing rice bran percentages (P < 0.001). Saturated fatty acids concentration decreased linearly (P < 0.01), while unsaturated fatty acids and omega-3 and omega-6 fatty acids increased linearly in response to increasing rice bran percentages (P < 0.05). The concentration of α-tocopherol in sausages increased linearly in response to increasing rice bran percentages (P < 0.01). Also, antioxidant activity increased linearly in sausages in response to added rice bran (P < 0.01). The cholesterol concentration of sausages did not vary significantly in response to added rice bran.

Rice straw as a feedstock for biofuels: Availability, recalcitrance, and chemical properties: Rice straw as a feedstock for biofuels

Energy Technology Data Exchange (ETDEWEB)

Satlewal, Alok [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Joint Inst. for Biological Sciences, Biosciences Division; Indian Oil Corporation Ltd, Faridabad (India), Dept. of Bioenergy, DBT-IOC Centre for Advanced Bioenergy Research, Research and Development Centre; Agrawal, Ruchi [Indian Oil Corporation Ltd, Faridabad (India), Dept. of Bioenergy, DBT-IOC Centre for Advanced Bioenergy Research, Research and Development Centre; Bhagia, Samarthya [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Das, Parthapratim [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Ragauskas, Arthur J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering

2017-10-17

The surplus availability of rice straw, its limited usage and environment pollution caused by inefficient burning has fostered research for its valorization to biofuels. This review elucidates the current status of rice straw potential around the globe along with recent advances in revealing the critical factors responsible for its recalcitrance and chemical properties. The role and accumulation of high silica content in rice straw has been elucidated with its impact on enzymatic hydrolysis in a biorefinery environment. The correlation of different pretreatment approaches in modifying the physiochemical properties of rice straw and improving the enzymatic accessibility has also been discussed. This study highlights new challenges, resolutions and opportunities for rice straw based biorefineries.

Nuclear Disarmament and the Insanity Defense: What Happened to Political Responsiveness?

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Fleming, John H.; Shaver, Kelly G.

A study which explored the degree to which belief in a politically responsive/unresponsive world might be related to opinions concerning nuclear disarmament, the insanity defense, and women's rights is described. A total of 206 male and female undergraduates completed a 63-item questionnaire consisting of 46 Likert-format I-E items and 17 attitude…

Interplay of Pathogen-Induced Defense Responses and Symbiotic Establishment in Medicago truncatula

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Tao Chen

2017-05-01

Full Text Available Suppression of host innate immunity appears to be required for the establishment of symbiosis between rhizobia and host plants. In this study, we established a system that included a host plant, a bacterial pathogen and a symbiotic rhizobium to study the role of innate immunity during symbiotic interactions. A pathogenic bacterium, Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000, was shown to cause chlorosis in Medicago truncatula A17. Sinorhizobium meliloti strain Sm2011 (Sm2011 and Pst DC3000 strain alone induced similar defense responses in M. truncatula. However, when co-inoculated, Sm2011 specifically suppressed the defense responses induced by Pst DC3000, such as MAPK activation and ROS production. Inoculation with Sm2011 suppressed the transcription of defense-related genes triggered by Pst DC3000 infection, including the receptor of bacterial flagellin (FLS2, pathogenesis-related protein 10 (PR10, and the transcription factor WRKY33. Interestingly, inoculation with Pst DC3000 specifically inhibited the expression of the symbiosis marker genes nodule inception and nodulation pectate lyase and reduced the numbers of infection threads and nodules on M. truncatula A17 roots, indicating that Pst DC3000 inhibits the establishment of symbiosis in M. truncatula. In addition, defense-related genes, such as MAPK3/6, RbohC, and WRKY33, exhibited a transient increase in their expression in the early stage of symbiosis with Sm2011, but the expression dropped down to normal levels at later symbiotic stages. Our results suggest that plant innate immunity plays an antagonistic role in symbiosis by directly reducing the numbers of infection threads and nodules.

Defense Response in Slash Pine: Chitosan Treatment Alters the Abundance of Specific mRNAs

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Mary E. Mason; John M. Davis

1997-01-01

We used differential display to identify chitosan responsive cDNAs in slashpine cell cultures. Two clones that showed increased mRNA abundance had sequence similarity to genes with roles in major plant defense responses, clone 18 to cinnamic acid 4-hydroxylase, and clone 30 to chitinase.

Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

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Saddam eHussain

2016-02-01

Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

The biocontrol endophytic bacterium Pseudomonas fluorescens PICF7 induces systemic defense responses in aerial tissues upon colonization of olive roots

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Carmen eGómez-Lama Cabanás

2014-09-01

Full Text Available Pseudomonas fluorescens PICF7, a native olive root endophyte and effective biocontrol agent (BCA against Verticillium wilt of olive, is able to trigger a broad range of defense responses in root tissues of this woody plant. In order to elucidate whether strain PICF7 also induces systemic defense responses in above-ground organs, aerial tissues of olive plants grown under non-gnotobiotic conditions were collected at different time points after root bacterization with this endophytic BCA. A suppression subtractive hybridization (SSH cDNA library, enriched in up-regulated genes, was generated. This strategy enabled the identification of 376 ESTs (99 contigs and 277 singlets, many of them related to response to different stresses. Five ESTs, involved in defense responses, were selected to carry out time-course quantitative real-time PCR (qRT-PCR experiments aiming to: (i validate the induction of these genes, and (ii shed light on their expression pattern along time (from 1 to 15 days. Induction of olive genes potentially coding for lypoxigenase 2, catalase, 1-aminocyclopropane-1-carboxylate oxidase and phenylananine ammonia-lyase was thus confirmed at some time points. Computational analysis also revealed that different transcription factors were up-regulated in olive aerial tissues (i.e. jerf, bHLH, WRKYs, as previously reported for roots. Results confirmed that root colonization by this endophytic bacterium does not only trigger defense responses in this organ but also mount a wide array of systemic defense responses in distant tissues (stems, leaves. This sheds light on how olive plants respond to the ‘non-hostile’ colonization by a bacterial endophyte and how induced defense response can contribute to the biocontrol activity of strain PICF7.

Antioxidant activity of rice plants sprayed with herbicides

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Marcos André Nohatto

2016-03-01

Full Text Available Understanding the physiological defense behavior of plants subjected to herbicide application may help to identify products with higher or lower capacity to cause oxidative stress in crops. This study aimed at evaluating the effect of herbicides in the antioxidant activity of rice plants. The experimental design was completely randomized, with six replications. Treatments consisted of the herbicides bentazon (photosystem II inhibitor; 960 g ha-1, penoxsulam (acetolactate synthase inhibitor; 60 g ha-1, cyhalofop-butyl (acetyl coenzyme-A carboxylase inhibitor; 315 g ha-1 and a control. After the herbicides application, samples of rice shoots were collected at 12, 24, 48 and 96 hours after application (HAA. The components evaluated were hydrogen peroxide (H2O2, lipid peroxidation and activity of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT. Bentazon (up to 24 HAA and penoxsulam (48 and 96 HAA reduced the CAT activity. Moreover, these herbicides increased the levels of H2O2, lipid peroxidation and SOD activity, indicating a condition of oxidative stress in rice plants. The cyhalofop-butyl herbicide did not alter the antioxidant activity, showing that it causes less stress to the crop.

Evaluation of Drought response in Some Rice Mutant Lines Using Stress Tolerance Indices

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H Aminpanah

2018-05-01

Full Text Available Introduction Drought is a major problem that limits the adoption of high-yielding rice varieties in drought-prone rainfed rice environments. To improve crop productivity, it is necessary to understand the mechanism of plant responses to drought conditions with the ultimate goal of improving crop performance in the vast areas of the world where rainfall is limiting or unreliable. Safaei Chaeikar et al. (2008 reported that MP, GMP, HM and STI indices, which showed the highest correlation with grain yield under both optimal and stress conditions, can be used as the best indices to introduce drought-tolerant genotypes in rice breeding programs. They also were introduced Nemat, Sepidrood, IR64, IR50 and Bejar genotypes as tolerant varieties. The present study was conducted to determine how drought affects grain yield in rice mutant lines and also to test this hypothesis in order to identify the most suitable indices/genotypes. Materials and Methods A field trial was conducted at Iranian Rice Research Centers in North of Iran, Rasht (latitude 37◦28', longitude 49◦28'E and altitude 7m below the sea level, during the 2014-2015 growing season. The seeds were sown in a nursery on the 10 May and 25 day old seedlings were transplanted to the field. Two separately experiment was carried out under reproductive stage drought stress and controlled conditions based on randomized complete block design with three replications, in four-row plots of three m length. Transplanting was done using 1 seedling per hill; at hill spacing of 25 cm × 25 cm. 18 rice genotypes were consisted 14 M5 mutant lines and their four parental cultivars. Results and Discussion Analysis of variance indicated significant effects of drought stress, genotype and interaction effects of two factors on grain yield, plant height, flag leaf area, tiller number and grain fertility percentage. Drought stress at reproductive stage caused reduction in grain yield (59.47%, grain fertility

Rice Cluster I, an Important Group of Archaea Producing Methane in Rice Fields

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Conrad, R.

2006-12-01

Rice fields are an important source for the greenhouse gas methane. Methane is a major degradation product of organic matter in the anoxic soil, is partially oxidized in the rhizosphere and is emitted into the atmosphere through the aerenchyma system of the plants. Anaerobic degradation of organic matter by fermenting bacteria eventually results in the production of acetate and hydrogen, the two major substrates for microbial methanogenesis. The community of methanogenic archaea consists of several major orders or families including hydrogen-utilizing Rice Cluster-I (RC-I). Environmental conditions affect the methanogenic degradation process and the community structure of the methanogenic archaea in soil and rhizosphere. For example, populations of acetoclastic Methanosaetaceae and Methanosarcinaceae are enhanced by low and high acetate concentrations, respectively. Stable isotope probing of 16S rRNA showed that RC-I methanogens are mainly active on rice roots and at low H2 concentrations. Growth and population size is largely consistent with energetic conditions. RC-I methanogens on roots seem to be responsible for methane production from plant photosynthates that account for a major part of the emitted methane. Populations of RC-I methanogens in rice field soil are also enhanced at elevated temperatures (40-50°C). Moderately thermophilic members of RC-I methanogens or other methanogenic families were found to be ubiquitously present in soils from rice fields and river marshes. The genome of a RC-I methanogen was completely sequenced out of an enrichment culture using a metagenome approach. Genes found are consistent with life in the rhizosphere and in temporarily drained, oxic soil. We found that the methanogenic community structure on the rice roots is mainly determined by the respective community structure of the soil, but is in addition affected by the rice cultivar. Rice microcosms in which soil and rice roots are mainly colonized by RC-I methanogens produce

Blood glucose lowering effects of brown rice in normal and diabetic subjects.

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Panlasigui, Leonora N; Thompson, Lilian U

2006-01-01

Carbohydrate foods, which produce low glycemic responses, have been shown to be beneficial in the dietary management of chronic diseases such as diabetes and hyperlipidemia. This study determined the starch digestion rate in vitro and, in a randomised crossover design, the postprandial blood glucose response of 10 healthy and nine type 2 diabetic volunteers to brown rice compared to milled rice from the same batch and variety. The total sugar released in vitro was 23.7% lower in brown rice than in milled rice. In healthy volunteers, the glycemic area and glycemic index were, respectively, 19.8% and 12.1% lower (p brown rice than milled rice, while in diabetics, the respective values were 35.2% and 35.6% lower. The effect was partly due to the higher amounts of phytic acid, polyphenols, dietary fiber and oil in brown compared to milled rice and the difference in some physicochemical properties of the rice samples such as minimum cooking time and degree of gelatinisation. In conclusion, brown rice is a more health beneficial food for diabetics and hyperglycemic individuals than milled rice.

Dynamic extrafloral nectar production: the timing of leaf damage affects the defensive response in Senna mexicana var. chapmanii (Fabaceae).

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Jones, Ian M; Koptur, Suzanne

2015-01-01

• Extrafloral nectar (EFN) mediates food for protection mutualisms between plants and defensive insects. Understanding sources of variation in EFN production is important because such variations may affect the number and identity of visitors and the effectiveness of plant defense. We investigated the influence of plant developmental stage, time of day, leaf age, and leaf damage on EFN production in Senna mexicana var. chapmanii. The observed patterns of variation in EFN production were compared with those predicted by optimal defense theory.• Greenhouse experiments with potted plants were conducted to determine how plant age, time of day, and leaf damage affected EFN production. A subsequent field study was conducted to determine how leaf damage, and the resulting increase in EFN production, affected ant visitation in S. chapmanii.• More nectar was produced at night and by older plants. Leaf damage resulted in increased EFN production, and the magnitude of the response was greater in plants damaged in the morning than those damaged at night. Damage to young leaves elicited a stronger defensive response than damage to older leaves, in line with optimal defense theory. Damage to the leaves of S. chapmanii also resulted in significantly higher ant visitation in the field.• Extrafloral nectar is an inducible defense in S. chapmanii. Developmental variations in its production support the growth differentiation balance hypothesis, while within-plant variations and damage responses support optimal defense theory. © 2015 Botanical Society of America, Inc.

Bio-protective microbial agents from rhizosphere eco-systems trigger plant defense responses provide protection against sheath blight disease in rice (Oryza sativa L.).

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Singh, Udai B; Malviya, Deepti; Wasiullah; Singh, Shailendra; Pradhan, Jatindra K; Singh, Bhanu P; Roy, Manish; Imram, Mohd; Pathak, Neelam; Baisyal, B M; Rai, Jai P; Sarma, B K; Singh, Rajiv K; Sharma, P K; Kaur, Saman Deep; Manna, M C; Sharma, Sushil K; Sharma, Arun K

2016-11-01

Sheath blight of rice (Oryza sativa L.) caused by Rhizoctonia solani is a major disease and attempts are being made to develop microbe based technologies for biocontrol of this pathogen. However, the mechanisms of biocontrol are not fully understood and still require indepth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed at deciphering the mechanisms of biocontrol of sheath blight of rice employing Pseudomonas fluorescens and Trichoderma harzianum as model agents for biocontrol. Initially 25, 5 and 5 strains of P. fluorescens, T. viride and T. harzianum, respectively, were screened for their biocontrol potential. Out of which, six strains with higher value of percent inhibition of fungal mycelium in dual plate assay were selected. The role of P. fluorescens, T. viride and T. harzianum were investigated in induction and bioaccumulation of natural antioxidants, defence-related biomolecules and other changes in plant which lead not only to growth promotion but also protection from pathogenic stress conditions in rice. The two most promising strains, P. fluorescens PF-08 and T. harzianum UBSTH-501 selected on the basis of in planta evaluation, when applied individually or in combination, significantly enhanced the accumulation of defence-related biomolecules, enzymes and exhibited biocontrol potential against R. solani. A modified/newly developed delivery system was applied for the first time in the experiments involving inoculation of plants with both bioagents, viz. P. fluorescens PF-08 and T. harzianum UBSTH-501. Results suggested that application of P. fluorescens PF-08 and T. harzianum UBSTH-501 alone or in combination, not only helps in control of the disease but also increases plant growth along with reduction in application of toxic chemical pesticides. Copyright © 2016 Elsevier GmbH. All rights reserved.

Maize terpene volatiles serve as precursors to an array of defensive phytoalexins following insect and pathogen attack

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Phytoalexins are inducible biochemicals that locally protect plant tissues against biotic attack. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquiterpene vol...

Tomato NAC transcription factor SlSRN1 positively regulates defense response against biotic stress but negatively regulates abiotic stress response.

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Bo Liu

Full Text Available Biotic and abiotic stresses are major unfavorable factors that affect crop productivity worldwide. NAC proteins comprise a large family of transcription factors that play important roles in plant growth and development as well as in responses to biotic and abiotic stresses. In a virus-induced gene silencing-based screening to identify genes that are involved in defense response against Botrytis cinerea, we identified a tomato NAC gene SlSRN1 (Solanum lycopersicum Stress-related NAC1. SlSRN1 is a plasma membrane-localized protein with transactivation activity in yeast. Expression of SlSRN1 was significantly induced by infection with B. cinerea or Pseudomonas syringae pv. tomato (Pst DC3000, leading to 6-8 folds higher than that in the mock-inoculated plants. Expression of SlSRN1 was also induced by salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid and by drought stress. Silencing of SlSRN1 resulted in increased severity of diseases caused by B. cinerea and Pst DC3000. However, silencing of SlSRN1 resulted in increased tolerance against oxidative and drought stresses. Furthermore, silencing of SlSRN1 accelerated accumulation of reactive oxygen species but attenuated expression of defense genes after infection by B. cinerea. Our results demonstrate that SlSRN1 is a positive regulator of defense response against B. cinerea and Pst DC3000 but is a negative regulator for oxidative and drought stress response in tomato.

Characteristics of siRNAs derived from Southern rice black-streaked dwarf virus in infected rice and their potential role in host gene regulation.

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Xu, Donglin; Zhou, Guohui

2017-02-10

Virus-derived siRNAs (vsiRNAs)-mediated RNA silencing plays important roles in interaction between plant viruses and their hosts. Southern rice black-streaked dwarf virus (SRBSDV) is a newly emerged devastating rice reovirus with ten dsRNA genomic segments. The characteristics of SRBSDV-derived siRNAs and their biological implications in SRBSDV-rice interaction remain unexplored. VsiRNAs profiling from SRBSDV-infected rice samples was done via small RNA deep sequencing. The putative rice targets of abundantly expressed vsiRNAs were bioinformatically predicted and subjected to functional annotation. Differential expression analysis of rice targets and RNA silencing components between infected and healthy samples was done using RT-qPCR. The vsiRNA was barely detectable at 14 days post infection (dpi) but abundantly present along with elevated expression level of the viral genome at 28 dpi. From the 28-dpi sample, 70,878 reads of 18 ~ 30-nt vsiRNAs were recognized (which mostly were 21-nt and 22-nt), covering 75 ~ 91% of the length of the ten genomic segments respectively. 86% of the vsiRNAs had a rice genes, including several types of host resistance or pathogenesis related genes encoding F-box/LRR proteins, receptor-like protein kinases, universal stress proteins, tobamovirus multiplication proteins, and RNA silencing components OsDCL2a and OsAGO17 respectively, some of which showed down regulation in infected plants in RT-qPCR. GO and KEGG classification showed that a majority of the predicted targets were related to cell parts and cellular processes and involved in carbohydrate metabolism, translation, and signal transduction. The silencing component genes OsDCL2a, OsDCL2b, OsDCL4, and OsAGO18 were down regulated, while OsAGO1d, OsAGO2, OsRDR1 and OsRDR6 were up regulated, significantly, upon SRBSDV infection. SRBSDV can regulate the expression of rice RNA silencing pathway components and the virus might compromise host defense and influence host

Rice weevil response to basil oil fumigation

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Basil oil, Ocimum basilicum L., is a volatile plant essential oil that is known to have insecticidal activity against stored product pests such as rice weevil, Sitophilus oryzae (L.). Basil oil was diluted in acetone and applied to a sponge held inside a tea strainer for fumigations in containers wi...

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

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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.

Effectors from Wheat Rust Fungi Suppress Multiple Plant Defense Responses.

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Ramachandran, Sowmya R; Yin, Chuntao; Kud, Joanna; Tanaka, Kiwamu; Mahoney, Aaron K; Xiao, Fangming; Hulbert, Scot H

2017-01-01

Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.

Transgenerational effects and impact of compensatory responses to changes in breeding phenology on antipredator defenses.

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Orizaola, Germán; Richter-Boix, Alex; Laurila, Anssi

2016-09-01

As organisms living in temperate environments often have only a short time window for growth and reproduction, their life-history strategies are expected to be influenced by these time constraints. Parents may alter the pace of offspring life-history as a response to changes in breeding phenology. However, the responses to changes in time constraints must be balanced with those against other stressors, such as predation, one of the strongest and more ubiquitous selective factors in nature. Here, after experimentally modifying the timing of breeding and hatching in the moor frog (Rana arvalis), we studied how compensatory responses to delayed breeding and hatching affect antipredator strategies in amphibian larvae. We examined the activity patterns, morphology and life-history responses in tadpoles exposed to different combinations of breeding and hatching delays in the presence and absence of predators. We found clear evidence of adaptive transgenerational effects since tadpoles from delayed breeding treatments increased growth and development independently of predation risk. The presence of predators reduced tadpole activity, tadpoles from delayed breeding treatments maintaining lower activity than non-delayed ones also in the absence of predators. Tadpoles reared with predators developed deeper tails and bodies, however, tadpoles from breeding delay treatments had reduced morphological defenses as compared to non-delayed individuals. No significant effects of hatching delay were detected in this study. Our study reveals that amphibian larvae exposed to breeding delay develop compensatory life-history responses even under predation risk, but these responses trade-off with the development of morphological antipredator defenses. These results suggest that under strong time constraints organisms are selected to develop fast growth and development responses, and rely on lower activity rates as their main antipredator defense. Examining how responses to changes in

OxyR-regulated catalase CatB promotes the virulence in rice via detoxifying hydrogen peroxide in Xanthomonas oryzae pv. oryzae.

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Yu, Chao; Wang, Nu; Wu, Maosen; Tian, Fang; Chen, Huamin; Yang, Fenghuan; Yuan, Xiaochen; Yang, Ching-Hong; He, Chenyang

2016-11-08

To facilitate infection, Xanthomonas oryzae pv. oryzae (Xoo), the bacterial blight pathogen of rice, needs to degrade hydrogen peroxide (H 2 O 2 ) generated by the host defense response via a mechanism that is mediated by the transcriptional regulator OxyR. The catalase (CAT) gene catB has previously been shown to belong to the OxyR regulon in Xoo. However, its expression patterns and function in H 2 O 2 detoxification and bacterial pathogenicity on rice remain to be elucidated. The catB gene encodes a putative catalase and is highly conserved in the sequenced strains of Xanthomonas spp. β-galactosidase analysis and electrophoretic mobility shift assays (EMSA) showed that OxyR positively regulated the transcription of catB by directly binding to its promoter region. The quantitative real-time PCR (qRT-PCR) assays revealed that the expression levels of catB and oxyR were significantly induced by H 2 O 2 . Deletion of catB or oxyR drastically impaired bacterial viability in the presence of extracellular H 2 O 2 and reduced CAT activity, demonstrating that CatB and OxyR contribute to H 2 O 2 detoxification in Xoo. In addition, ΔcatB and ΔoxyR displayed shorter bacterial blight lesions and reduced bacterial growth in rice compared to the wild-type stain, indicating that CatB and OxyR play essential roles in the virulence of Xoo. Transcription of catB is enhanced by OxyR in response to exogenous H 2 O 2 . CatB functions as an active catalase that is required for the full virulence of Xoo in rice.

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

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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.

Cadmium and lead interactive effects on oxidative stress and antioxidative responses in rice seedlings.

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Srivastava, Rajneesh Kumar; Pandey, Poonam; Rajpoot, Ritika; Rani, Anjana; Dubey, R S

2014-09-01

Interactive effects of two heavy metal pollutants Cd and Pb in the growth medium were examined on their uptake, production of reactive oxygen species (ROS), induction of oxidative stress and antioxidative defence responses in Indica rice (Oryza sativa L.) seedlings. When rice seedlings in sand culture were exposed to 150 μM Cd (NO3)2 or 600 μM Pb (CH3COO)2 individually or in combination for 8-16 days, a significant reduction in root/shoot length, fresh weight, relative water content, photosynthetic pigments and increased production of ROS (O2˙- and H2O2) was observed. Both Cd and Pb were readily taken up by rice roots and localisation of absorbed metals was greater in roots than in shoots. When present together in the growth medium, uptake of both the metals Cd and Pb declined by 25-40%. Scanning electron microscope (SEM) imaging of leaf stomata revealed that Pb caused more distortion in the shape of guard cells than Cd. Dithizone staining of roots showed localisation of absorbed Cd on root hairs and epidermal cells. Both Cd and Pb caused increased lipid peroxidation, protein carbonylation, decline in protein thiol and increase in non-protein thiol. The level of reduced forms of non-enzymic antioxidants glutathione (GSH) and ascorbate (AsA) and their redox ratios (GSH/AsA) declined, whereas the activities of antioxidative enzymes superoxide dismutase (SOD) and guaiacol peroxidase (GPX) increased in metal treated seedlings compared to controls. In-gel activity staining also revealed increased intensities of SOD and GPX isoforms with metal treatments. Catalase (CAT) activity increased during early days (8 days) of metal exposure and declined by 16 days. Results suggest that oxidative stress is an important component in expression of Cd and Pb toxicities in rice, though uptake of both metals gets reduced considerably when present together in the medium.

Biosynthesis and emission of insect-induced methyl salicylate and methyl benzoate from rice

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Zhao, Nan [University of Tennessee, Knoxville (UTK); Guan, Ju [University of Tennessee, Knoxville (UTK); Ferrer, Jean-Luc [Universite Joseph Fourier, France; Engle, Nancy L [ORNL; Chern, Mawsheng [University of California, Davis; Ronald, Pamela [University of California, Davis; Tschaplinski, Timothy J [ORNL; Chen, Feng [University of Tennessee, Knoxville (UTK)

2010-01-01

Two benzenoid esters, methyl salicylate (MeSA) and methyl benzoate (MeBA), were detected from insect-damaged rice plants. By correlating metabolite production with gene expression analysis, five candidate genes encoding putative carboxyl methyltransferases were identified. Enzymatic assays with Escherichia coli-expressed recombinant proteins demonstrated that only one of the five candidates, OsBSMT1, has salicylic acid (SA) methyltransferase (SAMT) and benzoic acid (BA) methyltransferase (BAMT) activities for producing MeSA and MeBA, respectively. Whereas OsBSMT1 is phylogenetically relatively distant from dicot SAMTs, the three-dimensional structure of OsBSMT1, which was determined using homology-based structural modeling, is highly similar to those of characterized SAMTs. Analyses of OsBSMT1 expression in wild-type rice plants under various stress conditions indicate that the jasmonic acid (JA) signaling pathway plays a critical role in regulating the production and emission of MeSA in rice. Further analysis using transgenic rice plants overexpressing NH1, a key component of the SA signaling pathway in rice, suggests that the SA signaling pathway also plays an important role in governing OsBSMT1 expression and emission of its products, probably through a crosstalk with the JA signaling pathway. The role of the volatile products of OsBSMT1, MeSA and MeBA, in rice defense against insect herbivory is discussed.

Biosynthesis and emission of insect-induced methyl salicylate and methyl benzoate from rice.

Science.gov (United States)

Zhao, Nan; Guan, Ju; Ferrer, Jean-Luc; Engle, Nancy; Chern, Mawsheng; Ronald, Pamela; Tschaplinski, Timothy J; Chen, Feng

2010-04-01

Two benzenoid esters, methyl salicylate (MeSA) and methyl benzoate (MeBA), were detected from insect-damaged rice plants. By correlating metabolite production with gene expression analysis, five candidate genes encoding putative carboxyl methyltransferases were identified. Enzymatic assays with Escherichia coli-expressed recombinant proteins demonstrated that only one of the five candidates, OsBSMT1, has salicylic acid (SA) methyltransferase (SAMT) and benzoic acid (BA) methyltransferase (BAMT) activities for producing MeSA and MeBA, respectively. Whereas OsBSMT1 is phylogenetically relatively distant from dicot SAMTs, the three-dimensional structure of OsBSMT1, which was determined using homology-based structural modeling, is highly similar to those of characterized SAMTs. Analyses of OsBSMT1 expression in wild-type rice plants under various stress conditions indicate that the jasmonic acid (JA) signaling pathway plays a critical role in regulating the production and emission of MeSA in rice. Further analysis using transgenic rice plants overexpressing NH1, a key component of the SA signaling pathway in rice, suggests that the SA signaling pathway also plays an important role in governing OsBSMT1 expression and emission of its products, probably through a crosstalk with the JA signaling pathway. The role of the volatile products of OsBSMT1, MeSA and MeBA, in rice defense against insect herbivory is discussed. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Identification of Biomarkers for Defense Response to Plasmopara viticola in a Resistant Grape Variety

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Giulia Chitarrini

2017-09-01

Full Text Available Downy mildew (Plasmopara viticola is one of the most destructive diseases of the cultivated species Vitis vinifera. The use of resistant varieties, originally derived from backcrosses of North American Vitis spp., is a promising solution to reduce disease damage in the vineyards. To shed light on the type and the timing of pathogen-triggered resistance, this work aimed at discovering biomarkers for the defense response in the resistant variety Bianca, using leaf discs after inoculation with a suspension of P. viticola. We investigated primary and secondary metabolism at 12, 24, 48, and 96 h post-inoculation (hpi. We used methods of identification and quantification for lipids (LC-MS/MS, phenols (LC-MS/MS, primary compounds (GC-MS, and semi-quantification for volatile compounds (GC-MS. We were able to identify and quantify or semi-quantify 176 metabolites, among which 53 were modulated in response to pathogen infection. The earliest changes occurred in primary metabolism at 24–48 hpi and involved lipid compounds, specifically unsaturated fatty acid and ceramide; amino acids, in particular proline; and some acids and sugars. At 48 hpi, we also found changes in volatile compounds and accumulation of benzaldehyde, a promoter of salicylic acid-mediated defense. Secondary metabolism was strongly induced only at later stages. The classes of compounds that increased at 96 hpi included phenylpropanoids, flavonols, stilbenes, and stilbenoids. Among stilbenoids we found an accumulation of ampelopsin H + vaticanol C, pallidol, ampelopsin D + quadrangularin A, Z-miyabenol C, and α-viniferin in inoculated samples. Some of these compounds are known as phytoalexins, while others are novel biomarkers for the defense response in Bianca. This work highlighted some important aspects of the host response to P. viticola in a commercial variety under controlled conditions, providing biomarkers for a better understanding of the mechanism of plant defense and a

Application of response surface methodology for studying the product characteristics of extruded rice-cowpea-groundnut blends.

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Asare, Emmanuel Kwasi; Sefa-Dedeh, Samuel; Sakyi-Dawson, Esther; Afoakwa, Emmanuel Ohene

2004-08-01

Response surface methodology (with central composite rotatable design for k=3) was used to investigate the product properties of extruded rice-cowpea-groundnut blends in a single screw extruder. The combined effect of cowpea (0-20%), groundnut (0-10%), and feed moisture (14-48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded rice-legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R(2) values ranging from 52.8% (for the b-value) to 86.5% (for bulk density). The models developed suggested that the optimal process variables for the production of a puffed snack with an enhanced nutrition and spongy structure from a rice-cowpea-groundnut blend are low feed moisture of 14-20% and maximum additions of 20% cowpea and 10% groundnut. A lack-of-fit test showed no significance, indicating that the models adequately fitted the data.

Comparative Transcriptomic Analysis in Paddy Rice under Storage and Identification of Differentially Regulated Genes in Response to High Temperature and Humidity.

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Zhao, Chanjuan; Xie, Junqi; Li, Li; Cao, Chongjiang

2017-09-20

The transcriptomes of paddy rice in response to high temperature and humidity were studied using a high-throughput RNA sequencing approach. Effects of high temperature and humidity on the sucrose and starch contents and α/β-amylase activity were also investigated. Results showed that 6876 differentially expressed genes (DEGs) were identified in paddy rice under high temperature and humidity storage. Importantly, 12 DEGs that were downregulated fell into the "starch and sucrose pathway". The quantitative real-time polymerase chain reaction assays indicated that expression of these 12 DEGs was significantly decreased, which was in parallel with the reduced level of enzyme activities and the contents of sucrose and starch in paddy rice stored at high temperature and humidity conditions compared to the control group. Taken together, high temperature and humidity influence the quality of paddy rice at least partially by downregulating the expression of genes encoding sucrose transferases and hydrolases, which might result in the decrease of starch and sucrose contents.

GID1 modulates stomatal response and submergence tolerance involving abscisic acid and gibberellic acid signaling in rice.

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Du, Hao; Chang, Yu; Huang, Fei; Xiong, Lizhong

2015-11-01

Plant responses to abiotic stresses are coordinated by arrays of growth and developmental programs. Gibberellic acid (GA) and abscisic acid (ABA) play critical roles in the developmental programs and environmental responses, respectively, through complex signaling and metabolism networks. However, crosstalk between the two phytohormones in stress responses remains largely unknown. In this study, we report that GIBBERELLIN-INSENSITIVE DWARF 1 (GID1), a soluble receptor for GA, regulates stomatal development and patterning in rice (Oryza sativa L.). The gid1 mutant showed impaired biosynthesis of endogenous ABA under drought stress conditions, but it exhibited enhanced sensitivity to exogenous ABA. Scanning electron microscope and infrared thermal image analysis indicated an increase in the stomatal conductance in the gid1 mutant under drought conditions. Interestingly, the gid1 mutant had increased levels of chlorophyll and carbohydrates under submergence conditions, and showed enhanced reactive oxygen species (ROS)-scavenging ability and submergence tolerance compared with the wild-type. Further analyses suggested that the function of GID1 in submergence responses is partially dependent on ABA, and GA signaling by GID1 is involved in submergence tolerance by modulating carbohydrate consumption. Taken together, these findings suggest GID1 plays distinct roles in stomatal response and submergence tolerance through both the ABA and GA signaling pathways in rice. © 2014 Institute of Botany, Chinese Academy of Sciences.

Response of sunflower (Helianthus annuus L.) leaf surface defenses to exogenous methyl jasmonate.

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Rowe, Heather C; Ro, Dae-kyun; Rieseberg, Loren H

2012-01-01

Helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. The primary components of these trichome secretions are sesquiterpene lactones (STL), a diverse class of compounds produced abundantly by the plant family Compositae and believed to contribute to plant defense against herbivory. We treated wild and cultivated H. annuus accessions with exogenous methyl jasmonate, a plant hormone that mediates plant defense against insect herbivores and certain classes of fungal pathogens. The wild sunflower produced a higher density of glandular trichomes on its leaves than the cultivar. Comparison of the profiles of glandular trichome extracts obtained by liquid chromatography-mass spectroscopy (LC-MS) showed that wild and cultivated H. annuus were qualitatively similar in surface chemistry, although differing in the relative size and proportion of various compounds detected. Despite observing consistent transcriptional responses to methyl jasmonate treatment, we detected no significant effect on glandular trichome density or LC-MS profile in cultivated or wild sunflower, with wild sunflower exhibiting a declining trend in overall STL production and foliar glandular trichome density of jasmonate-treated plants. These results suggest that glandular trichomes and associated compounds may act as constitutive defenses or require greater levels of stimulus for induction than the observed transcriptional responses to exogenous jasmonate. Reduced defense investment in domesticated lines is consistent with predicted tradeoffs caused by selection for increased yield; future research will focus on the development of genetic resources to explicitly test the ecological roles of glandular trichomes and associated effects on plant growth and fitness.

Food protein induced enterocolitis syndrome caused by rice beverage.

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Caminiti, Lucia; Salzano, Giuseppina; Crisafulli, Giuseppe; Porcaro, Federica; Pajno, Giovanni Battista

2013-05-14

Food protein-induced enterocolitis syndrome (FPIES) is an uncommon and potentially severe non IgE-mediated gastrointestinal food allergy. It is usually caused by cow's milk or soy proteins, but may also be triggered by ingestion of solid foods. The diagnosis is made on the basis of clinical history and symptoms. Management of acute phase requires fluid resuscitation and intravenous steroids administration, but avoidance of offending foods is the only effective therapeutic option.Infant with FPIES presented to our emergency department with vomiting, watery stools, hypothension and metabolic acidosis after ingestion of rice beverage. Intravenous fluids and steroids were administered with good clinical response. Subsequently, a double blind placebo control food challenge (DBPCFC) was performed using rice beverage and hydrolyzed formula (eHF) as placebo. The "rice based formula" induced emesis, diarrhoea and lethargy. Laboratory investigations reveal an increase of absolute count of neutrophils and the presence of faecal eosinophils. The patient was treated with both intravenous hydration and steroids. According to Powell criteria, oral food challenge was considered positive and diagnosis of FPIES induced by rice beverage was made. Patient was discharged at home with the indication to avoid rice and any rice beverage as well as to reintroduce hydrolyzed formula. A case of FPIES induced by rice beverage has never been reported. The present case clearly shows that also beverage containing rice proteins can be responsible of FPIES. For this reason, the use of rice beverage as cow's milk substitute for the treatment of non IgE-mediated food allergy should be avoided.

Quantitative proteomic analysis of the rice (Oryza sativa L. salt response.

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Jianwen Xu

Full Text Available Salt stress is one of most serious limiting factors for crop growth and production. An isobaric Tags for Relative and Absolute Quantitation (iTRAQ approach was used to analyze proteomic changes in rice shoots under salt stress in this study. A total of 56 proteins were significantly altered and 16 of them were enriched in the pathways of photosynthesis, antioxidant and oxidative phosphorylation. Among these 16 proteins, peroxiredoxin Q and photosystem I subunit D were up-regulated, while thioredoxin M-like, thioredoxin x, thioredoxin peroxidase, glutathione S-transferase F3, PSI subunit H, light-harvesting antenna complex I subunits, chloroplast chaperonin, vacuolar ATP synthase subunit H, and ATP synthase delta chain were down-regulated. Moreover, physiological data including total antioxidant capacity, peroxiredoxin activity, chlorophyll a/b content, glutathione S-transferase activity, reduced glutathione content and ATPase activity were consistent with changes in the levels of these proteins. The levels of the mRNAs encoding these proteins were also analyzed by real-time quantitative reverse transcription PCR, and approximately 86% of the results were consistent with the iTRAQ data. Importantly, our data suggest the important role of PSI in balancing energy supply and ROS generation under salt stress. This study provides information for an improved understanding of the function of photosynthesis and PSI in the salt-stress response of rice.

Physiology and productivity of rice crop influenced by drought stress ...

African Journals Online (AJOL)

Rice is sensitive to moisture stress and in view of the water scarcity in the coming years, it is imperative to evaluate the performance of rice cultivar under moisture deficit. The present study aimed to evaluate the physiological responses of two rice cultivars under drought stress induced at panicle initiation and soft dough ...

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

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M. E. Santamaria

2018-04-01

Full Text Available Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production.

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

Science.gov (United States)

Santamaria, M. E.; Diaz, Isabel; Martinez, Manuel

2018-01-01

Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit) treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production. PMID:29681917

Problems and prospects of mechanical rice-transplanting in Pakistan

International Nuclear Information System (INIS)

Majid, A.; Rehman, A.; Akram, M.; Zafar, A.W.; Ahmed, M.

2003-01-01

Among the many factors, low plant-population is the fundamental reason for poor rice-yield, despite advancements in rice-culture technology. The contracted manual transplanting of paddy seedlings is considered to be one of the key factors responsible for poor stand-establishment of rice in the field. The labourers transplant rice-seedlings at considerably wider distance than the recommended one, resulting in poor establishment of crop-stand and, ultimately, lower yield. The mechanized rice-culture is thought to be a viable substitute for manual rice-culture in Pakistan. Over the years, a lot of effort has been made in this regard, but could not popularize mechanical transplantation of paddy, for a number of reasons. The popularization of mechanical rice-culture in the country needs significant reforms in nursery raising, water management, improvement of soil organic-matter and land-preparation, along with emphasis on local manufacturing of the cost-effective simple mechanical rice transplanter. (author)

Response of Glutathione and Glutathione S-transferase in Rice Seedlings Exposed to Cadmium Stress

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Chun-hua ZHANG

2008-03-01

Full Text Available A hydroponic culture experiment was done to investigate the effect of Cd stress on glutathione content (GSH and glutathione S-transferase (GST, EC 2.5.1.18 activity in rice seedlings. The rice growth was severely inhibited when Cd level in the solution was higher than 10 mg/L. In rice shoots, GSH content and GST activity increased with the increasing Cd level, while in roots, GST was obviously inhibited by Cd treatments. Compared with shoots, the rice roots had higher GSH content and GST activity, indicating the ability of Cd detoxification was much higher in roots than in shoots. There was a significant correlation between Cd level and GSH content or GST activity, suggesting that both parameters may be used as biomarkers of Cd stress in rice.

Temporal and spatial resolution of activated plant defense responses in leaves of Nicotiana benthamiana infected with Dickeya dadantii

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María Luisa ePérez-Bueno

2016-01-01

Full Text Available The necrotrophic bacteria Dickeya dadantii is the causal agent of soft-rot disease in a broad range of hosts. The model plant Nicotiana benthamiana, commonly used as experimental host for a very broad range of plant pathogens, is susceptible to infection by D. dadantii. The inoculation with D. dadantii at high dose seems to overcome the plant defense capacity, inducing maceration and death of the tissue, although restricted to the infiltrated area. By contrast, the output of the defense response to low dose inoculation is inhibition of maceration and limitation in the growth, or even eradication, of bacteria. Responses of tissue invaded by bacteria (neighbouring the infiltrated areas after 2-3 days post-inoculation included: i inhibition of photosynthesis in terms of photosystem II efficiency; ii activation of energy dissipation as non-photochemical quenching in photosystem II, which is related to the activation of plant defense mechanisms; and iii accumulation of secondary metabolites in cell walls of the epidermis (lignins and the apoplast of the mesophyll (phytoalexins. Infiltrated tissues showed an increase in the content of the main hormones regulating stress responses, including abscisic acid (ABA, jasmonic acid (JA and salicylic acid (SA. We propose a mechanism involving the three hormones by which N. benthamiana could activate an efficient defense response against D. dadantii.

Rice yield in response to climate trends and drought index in the Mun River Basin, Thailand

NARCIS (Netherlands)

Prabnakom, S.; Maskey, S.; Suryadi, F.X.; Fraiture, de C.M.S.

2018-01-01

Rice yields in Thailand are among the lowest in Asia. In northeast Thailand where about 90% of rice cultivation is rain-fed, climate variability and change affect rice yields. Understanding climate characteristics and their impacts on the rice yield is important for establishing proper adaptation

Environmental Response and Genomic Regions Correlated with Rice Root Growth and Yield under Drought in the OryzaSNP Panel across Multiple Study Systems.

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Len J Wade

Full Text Available The rapid progress in rice genotyping must be matched by advances in phenotyping. A better understanding of genetic variation in rice for drought response, root traits, and practical methods for studying them are needed. In this study, the OryzaSNP set (20 diverse genotypes that have been genotyped for SNP markers was phenotyped in a range of field and container studies to study the diversity of rice root growth and response to drought. Of the root traits measured across more than 20 root experiments, root dry weight showed the most stable genotypic performance across studies. The environment (E component had the strongest effect on yield and root traits. We identified genomic regions correlated with root dry weight, percent deep roots, maximum root depth, and grain yield based on a correlation analysis with the phenotypes and aus, indica, or japonica introgression regions using the SNP data. Two genomic regions were identified as hot spots in which root traits and grain yield were co-located; on chromosome 1 (39.7-40.7 Mb and on chromosome 8 (20.3-21.9 Mb. Across experiments, the soil type/ growth medium showed more correlations with plant growth than the container dimensions. Although the correlations among studies and genetic co-location of root traits from a range of study systems points to their potential utility to represent responses in field studies, the best correlations were observed when the two setups had some similar properties. Due to the co-location of the identified genomic regions (from introgression block analysis with QTL for a number of previously reported root and drought traits, these regions are good candidates for detailed characterization to contribute to understanding rice improvement for response to drought. This study also highlights the utility of characterizing a small set of 20 genotypes for root growth, drought response, and related genomic regions.

Light Influences How the Fungal Toxin Deoxynivalenol Affects Plant Cell Death and Defense Responses

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Khairul I. Ansari

2014-02-01

Full Text Available The Fusarium mycotoxin deoxynivalenol (DON can cause cell death in wheat (Triticum aestivum, but can also reduce the level of cell death caused by heat shock in Arabidopsis (Arabidopsis thaliana cell cultures. We show that 10 μg mL−1 DON does not cause cell death in Arabidopsis cell cultures, and its ability to retard heat-induced cell death is light dependent. Under dark conditions, it actually promoted heat-induced cell death. Wheat cultivars differ in their ability to resist this toxin, and we investigated if the ability of wheat to mount defense responses was light dependent. We found no evidence that light affected the transcription of defense genes in DON-treated roots of seedlings of two wheat cultivars, namely cultivar CM82036 that is resistant to DON-induced bleaching of spikelet tissue and cultivar Remus that is not. However, DON treatment of roots led to genotype-dependent and light-enhanced defense transcript accumulation in coleoptiles. Wheat transcripts encoding a phenylalanine ammonia lyase (PAL gene (previously associated with Fusarium resistance, non-expressor of pathogenesis-related genes-1 (NPR1 and a class III plant peroxidase (POX were DON-upregulated in coleoptiles of wheat cultivar CM82036 but not of cultivar Remus, and DON-upregulation of these transcripts in cultivar CM82036 was light enhanced. Light and genotype-dependent differences in the DON/DON derivative content of coleoptiles were also observed. These results, coupled with previous findings regarding the effect of DON on plants, show that light either directly or indirectly influences the plant defense responses to DON.

Plant defense response against Fusarium oxysporum and strategies to develop tolerant genotypes in banana.

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Swarupa, V; Ravishankar, K V; Rekha, A

2014-04-01

Soil-borne fungal pathogen, Fusarium oxysporum causes major economic losses by inducing necrosis and wilting symptoms in many crop plants. Management of fusarium wilt is achieved mainly by the use of chemical fungicides which affect the soil health and their efficiency is often limited by pathogenic variability. Hence understanding the nature of interaction between pathogen and host may help to select and improve better cultivars. Current research evidences highlight the role of oxidative burst and antioxidant enzymes indicating that ROS act as an important signaling molecule in banana defense response against Fusarium oxysporum f.sp. cubense. The role of jasmonic acid signaling in plant defense against necrotrophic pathogens is well recognized. But recent studies show that the role of salicylic acid is complex and ambiguous against necrotrophic pathogens like Fusarium oxysporum, leading to many intriguing questions about its relationship between other signaling compounds. In case of banana, a major challenge is to identify specific receptors for effector proteins like SIX proteins and also the components of various signal transduction pathways. Significant progress has been made to uncover the role of defense genes but is limited to only model plants such as Arabidopsis and tomato. Keeping this in view, we review the host response, pathogen diversity, current understanding of biochemical and molecular changes that occur during host and pathogen interaction. Developing resistant cultivars through mutation, breeding, transgenic and cisgenic approaches have been discussed. This would help us to understand host defenses against Fusarium oxysporum and to formulate strategies to develop tolerant cultivars.

Transcriptomic Analysis of Gibberellin- and Paclobutrazol-Treated Rice Seedlings under Submergence

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Jing Xiang

2017-10-01

Full Text Available Submergence stress is a limiting factor for rice growing in rainfed lowland areas of the world. It is known that the phytohormone gibberellin (GA has negative effects on submergence tolerance in rice, while its inhibitor paclobutrazol (PB does the opposite. However, the physiological and molecular basis underlying the GA- and PB-regulated submergence response remains largely unknown. In this study, we reveal that PB could significantly enhance rice seedling survival by retaining a higher level of chlorophyll content and alcohol dehydrogenase activity, and decelerating the consumption of non-structure carbohydrate when compared with the control and GA-treated samples. Further transcriptomic analysis identified 3936 differentially expressed genes (DEGs among the GA- and PB-treated samples and control, which are extensively involved in the submergence and other abiotic stress responses, phytohormone biosynthesis and signaling, photosynthesis, and nutrient metabolism. The results suggested that PB enhances rice survival under submergence through maintaining the photosynthesis capacity and reducing nutrient metabolism. Taken together, the current study provided new insight into the mechanism of phytohormone-regulated submergence response in rice.

Genome-wide Differences in DNA Methylation Changes in Two Contrasting Rice Genotypes in Response to Drought Conditions

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Wensheng Wang

2016-11-01

Full Text Available Differences in drought stress tolerance within diverse rice genotypes have been attributed to genetic diversity and epigenetic alterations. DNA methylation is an important epigenetic modification that influences diverse biological processes, but its effects on rice drought stress tolerance are poorly understood. In this study, methylated DNA immunoprecipitation sequencing and an Affymetrix GeneChip rice genome array were used to profile the DNA methylation patterns and transcriptomes of the drought-tolerant introgression line DK151 and its drought-sensitive recurrent parent IR64 under drought and control conditions. The introgression of donor genomic DNA induced genome-wide DNA methylation changes in DK151 plants. A total of 1190 differentially methylated regions (DMRs were detected between the two genotypes under normal growth conditions, and the DMR-associated genes in DK151 plants were mainly related to stress response, programmed cell death, and nutrient reservoir activity, which are implicated to constitutive drought stress tolerance. A comparison of the DNA methylation changes in the two genotypes under drought conditions indicated that DK151 plants have a more stable methylome, with only 92 drought-induced DMRs, than IR64 plants with 506 DMRs. Gene ontology analyses of the DMR-associated genes in drought-stressed plants revealed that changes to the DNA methylation status of genotype-specific genes are associated with the epigenetic regulation of drought stress responses. Transcriptome analysis further helped to identify a set of 12 and 23 DMR-associated genes that were differentially expressed in DK151 and IR64, respectively, under drought stress compared with respective controls. Correlation analysis indicated that DNA methylation has various effects on gene expression, implying that it affects gene expression directly or indirectly through diverse regulatory pathways. Our results indicate that drought-induced alterations to DNA

Cloning and Expression Analysis of an AP2/ERF Gene and Its Responses to Phytohormones and Abiotic Stresses in Rice

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Hao-li MA

2010-03-01

Full Text Available Ethylene response factors (ERFs play important roles in response to plant biotic and abiotic stresses. In this study, a gene encoding a putative AP2/ERF domain-containing protein was isolated by screening a SSH cDNA library from rice and designated as Oryza sativa AP2/ERF-like protein (OsAP2LP gene. OsAP2LP is 1491 bp in length, interrupted by seven introns, and encodes a putative protein of 348 amino acids. Temporal and spatial expression analysis showed that the OsAP2LP gene was preferentially expressed in roots, panicles, mature embryos and seeds in rice. Real-time quantitative PCR analysis indicated that the expression levels of the OsAP2LP gene were increased under the treatments of drought and gibberellin but decreased under the treatments of low temperature, salt, abscisic acid (ABA and zeatin. Taken together, these results suggest that OsAP2LP might be involved in stress responses, and probably plays roles as a transcription regulator when plants response to cold, salt and drought stresses through ABA and gibberellin pathways.

Assessment of reference gene stability in Rice stripe virus and Rice black streaked dwarf virus infection rice by quantitative Real-time PCR.

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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.

Diurnal changes in CN metabolism and response of rice seedlings to UV-B radiation.

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Yun, Hyejin; Lim, Sunhyung; Kim, Yangmin X; Lee, Yejin; Lee, Seulbi; Lee, Deogbae; Park, Keewoong; Sung, Jwakyung

2018-03-13

Plants regulate a number of primary metabolites, including carbohydrates, organic acids, and amino acids, in response to UV-B radiation. Therefore, it is essential to understand the time-dependent response of rice plants to UV-B stress. This study focused on the response of plants to UV-B at different leaf developmental phases (emerging, growing, and maturing) in an attempt to fully comprehend the metabolic shift. We analyzed the expression levels of genes related to starch/sucrose metabolism in the leaf blades of rice seedlings (Oryza sativa L. "Saechuchenog") exposed to UV-B irradiation for short (1 day) and long terms (5 days) using quantitative real-time polymerase chain reaction. We also examined the diurnal variations in the contents of primary metabolites using an established GCTOF-MS (gas chromatography time of flight-mass spectrometry) method. The results showed that the levels of primary metabolites were largely dependent upon the diurnal rhythm and leaf developmental phase. The young leaves (sink) produced and accumulated starch rather than sucrose. The short-term (4 h, 1 day) UV-B exposure inhibited sucrose synthesis, which could be the first target of UV-B radiation. Following short- and long-term (5 days) exposure to UV-B radiation, the dynamic response of primary metabolites was evaluated. It was found that the content of carbohydrates decreased throughout the period of exposure to UV-B stress, especially in terms of sucrose concentration. However, the content of the majority of amino acids increased after an early decrease. Our data revealed that the metabolic response, as well as the gene expression, differed with the period (intensity) of exposure to UV-B radiation and with the phase of leaf development. These findings provide new insights for a better understanding of the metabolic response of a variety of plant species exposed to a wide range of UV-B radiation. Copyright © 2018. Published by Elsevier GmbH.

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

Gibberellin homeostasis and plant height control by EUI and a role for gibberellin in root gravity responses in rice.

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Zhang, Yingying; Zhu, Yongyou; Peng, Yu; Yan, Dawei; Li, Qun; Wang, Jianjun; Wang, Linyou; He, Zuhua

2008-03-01

The rice Eui (ELONGATED UPPERMOST INTERNODE) gene encodes a cytochrome P450 monooxygenase that deactivates bioactive gibberellins (GAs). In this study, we investigated controlled expression of the Eui gene and its role in plant development. We found that Eui was differentially induced by exogenous GAs and that the Eui promoter had the highest activity in the vascular bundles. The eui mutant was defective in starch granule development in root caps and Eui overexpression enhanced starch granule generation and gravity responses, revealing a role for GA in root starch granule development and gravity responses. Experiments using embryoless half-seeds revealed that RAmy1A and GAmyb were highly upregulated in eui aleurone cells in the absence of exogenous GA. In addition, the GA biosynthesis genes GA3ox1 and GA20ox2 were downregulated and GA2ox1 was upregulated in eui seedlings. These results indicate that EUI is involved in GA homeostasis, not only in the internodes at the heading stage, but also in the seedling stage, roots and seeds. Disturbing GA homeostasis affected the expression of the GA signaling genes GID1 (GIBBERELLIN INSENSITIVE DWARF 1), GID2 and SLR1. Transgenic RNA interference of the Eui gene effectively increased plant height and improved heading performance. By contrast, the ectopic expression of Eui under the promoters of the rice GA biosynthesis genes GA3ox2 and GA20ox2 significantly reduced plant height. These results demonstrate that a slight increase in Eui expression could dramatically change rice morphology, indicating the practical application of the Eui gene in rice molecular breeding for a high yield potential.

Functional analysis of rice HOMEOBOX4 (Oshox4) gene reveals a negative function in gibberellin responses.

Science.gov (United States)

Dai, Mingqiu; Hu, Yongfeng; Ma, Qian; Zhao, Yu; Zhou, Dao-Xiu

2008-02-01

The homeodomain-leucine zipper (HD-Zip) putative transcription factor genes are divided into 4 families. In this work, we studied the function of a rice HD-Zip I gene, H OME O BO X4 (Oshox4). Oshox4 transcripts were detected in leaf and floral organ primordia but excluded from the shoot apical meristem and the protein was nuclear localized. Over-expression of Oshox4 in rice induced a semi-dwarf phenotype that could not be complemented by applied GA3. The over-expression plants accumulated elevated levels of bioactive GA, while the GA catabolic gene GA2ox3 was upregulated in the transgenic plants. In addition, over-expression of Oshox4 blocked GA-dependent alpha-amylase production. However, down-regulation of Oshox4 in RNAi transgenic plants induced no phenotypic alteration. Interestingly, the expression of YAB1 that is involved in the negative feedback regulation of the GA biosynthesis was upregulated in the Oshox4 over-expressing plants. One-hybrid assays showed that Oshox4 could interact with YAB1 promoter in yeast. In addition, Oshox4 expression was upregulated by GA. These data together suggest that Oshox4 may be involved in the negative regulation of GA signalling and may play a role to fine tune GA responses in rice.

Transcriptome and Cell Physiological Analyses in Different Rice Cultivars Provide New Insights Into Adaptive and Salinity Stress Responses

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Elide Formentin

2018-03-01

Full Text Available Salinity tolerance has been extensively investigated in recent years due to its agricultural importance. Several features, such as the regulation of ionic transporters and metabolic adjustments, have been identified as salt tolerance hallmarks. Nevertheless, due to the complexity of the trait, the results achieved to date have met with limited success in improving the salt tolerance of rice plants when tested in the field, thus suggesting that a better understanding of the tolerance mechanisms is still required. In this work, differences between two varieties of rice with contrasting salt sensitivities were revealed by the imaging of photosynthetic parameters, ion content analysis and a transcriptomic approach. The transcriptomic analysis conducted on tolerant plants supported the setting up of an adaptive program consisting of sodium distribution preferentially limited to the roots and older leaves, and in the activation of regulatory mechanisms of photosynthesis in the new leaves. As a result, plants resumed grow even under prolonged saline stress. In contrast, in the sensitive variety, RNA-seq analysis revealed a misleading response, ending in senescence and cell death. The physiological response at the cellular level was investigated by measuring the intracellular profile of H2O2 in the roots, using a fluorescent probe. In the roots of tolerant plants, a quick response was observed with an increase in H2O2 production within 5 min after salt treatment. The expression analysis of some of the genes involved in perception, signal transduction and salt stress response confirmed their early induction in the roots of tolerant plants compared to sensitive ones. By inhibiting the synthesis of apoplastic H2O2, a reduction in the expression of these genes was detected. Our results indicate that quick H2O2 signaling in the roots is part of a coordinated response that leads to adaptation instead of senescence in salt-treated rice plants.

An early response regulatory cluster induced by low temperature and hydrogen peroxide in seedlings of chilling-tolerant japonica rice

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Jia Yulin

2007-06-01

Full Text Available Abstract Background Plants respond to low temperature through an intricately coordinated transcriptional network. The CBF/DREB-regulated network of genes has been shown to play a prominent role in freeze-tolerance of Arabidopsis through the process of cold acclimation (CA. Recent evidence also showed that the CBF/DREB regulon is not unique to CA but evolutionarily conserved between chilling-insensitive (temperate and chilling-sensitive (warm-season plants. In this study, the wide contrast in chilling sensitivity between indica and japonica rice was used as model to identify other regulatory clusters by integrative analysis of promoter architecture (ab initio and gene expression profiles. Results Transcriptome analysis in chilling tolerant japonica rice identified a subset of 121 'early response' genes that were upregulated during the initial 24 hours at 10°C. Among this group were four transcription factors including ROS-bZIP1 and another larger sub-group with a common feature of having as1/ocs-like elements in their promoters. Cold-induction of ROS-bZIP1 preceded the induction of as1/ocs-like element-containing genes and they were also induced by exogenous H2O2 at ambient temperature. Coordinated expression patterns and similar promoter architectures among the 'early response' genes suggest that they belong to a potential regulon (ROS-bZIP – as1/ocs regulatory module that responds to elevated levels of ROS during chilling stress. Cultivar-specific expression signatures of the candidate genes indicate a positive correlation between the activity of the putative regulon and genotypic variation in chilling tolerance. Conclusion A hypothetical model of an ROS-mediated regulon (ROS-bZIP – as1/ocs triggered by chilling stress was assembled in rice. Based on the current results, it appears that this regulon is independent of ABA and CBF/DREB, and that its activation has an important contribution in configuring the rapid responses of rice seedlings

The Response of Rice Root to Time Course Water Deficit Stress-Two Dimensional Electrophoresis Approach

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Mahmood Toorchi

2015-11-01

Full Text Available Rice (Oryza sativa L. is the staple food of more than half of the population worldwide. Water deficit stress is one of the harsh limiting factors for successful production of crops. Rice during its growing period comes a cross different environmental hazards like drought stress. Recent advance in molecular physiology are promising for more progress in increasing rice yield by identification of novel candidate proteins for drought tolerance. To investigate the effect of water deficit on rice root protein expression pattern, an experiment was conducted in completely randomize design with four replications. With holding water for 24, 36 and 48 hours along with control constituted the experimental treatments. The experiment was conducted in growth chamber under controlled condition and root samples, after stress imposition, were harvested for two-dimensional electrophorese (2-DE. Proteome analysis of root tissue by 2-DE indicated that out of 135 protein spots diagnosed by Coomassie blue staining, 14 spots showed significant expression change under water deficit condition, seven of them at 1% and the other seven at 5% probability levels. Differentially changed proteins were taken into account for search in data bank using isoelectric point and molecular weight to identify the most probable responsive proteins. Up- regulation of ferredoxin oxidoreductase at first 24 hour after applying stress indicates the main role of this protein in reducing water deficit stress effects. On the other hand ribosomal proteins, GAP-3 and ATP synthase were down regulated under water deficit stress. Fructose 1,6-bisphosphate aldolase, glucose- 6-phosphate dehydrogenase and chitinase down regulated up to 36 h of stress imposition but, were later up- regulated by prolonging stress up to 48 h. It could be inferred the plant tries to decrease the effect of oxidative stress.

[Response of rice grain quality traits to free-air CO2 enrichment].

Science.gov (United States)

Dong, Guichun; Wang, Yulong; Huang, Jianye; Yang, Hongjian; Gu, Hui; Peng, Bin; Ju, Jing; Yang, Lianxin; Zhu, Jianguo; Shan, Yuhua

2004-07-01

The study showed that under field condition, when the CO2 concentration was elevated 200 micromol x mol(-1) above control, the average brown rice rate of japonica variety Wuxiangjing 14 was 1.4% higher, while lead milled rice rate was 12.3% lower than control. The brown rice rate increased at lower nitrogen supply level (LN), while lead milled rice rate increased at higher nitrogen supply level (HN). The percentage of chalky grain was 11.9% higher, and chalkiness degree was 2.8% higher than control, but no obvious difference was found in chalkiness area between the FACE and the control. The chalkiness area, percentage of chalky grain and chalkiness degree decreased at HN plus higher phosphorus supply level (HP). The gelatinization temperature was elevated 0.52 degrees C, gel consistency increased, while amylose content was not statistically significant. The amylose content decreased at HN plus HP, while gel consistency and gelatinization temperature decreased at LN plus HP and at LN, respectively. The protein content was decreased 0.6% under FACE treatment and at LN plus lower phosphorus supply level.

Impacts of aerosol mitigation on Chinese rice photosynthesis: An integrated modeling approach

Science.gov (United States)

Zhang, T.; Li, T.; Yue, X.; Yang, X.

2017-12-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ an integrated process-based modeling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. This response pattern and threshold are similar with observations, even through more data are needed in future investigation. As a net effect, rice yields were estimated to significantly increase by 0.8-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

ATL9, a RING zinc finger protein with E3 ubiquitin ligase activity implicated in chitin- and NADPH oxidase-mediated defense responses.

Directory of Open Access Journals (Sweden)

Marta Berrocal-Lobo

2010-12-01

Full Text Available Pathogen associated molecular patterns (PAMPs are signals detected by plants that activate basal defenses. One of these PAMPs is chitin, a carbohydrate present in the cell walls of fungi and in insect exoskeletons. Previous work has shown that chitin treatment of Arabidopsis thaliana induced defense-related genes in the absence of a pathogen and that the response was independent of the salicylic acid (SA, jasmonic acid (JA and ethylene (ET signaling pathways. One of these genes is ATL9 ( = ATL2G, which encodes a RING zinc-finger like protein. In the current work we demonstrate that ATL9 has E3 ubiquitin ligase activity and is localized to the endoplasmic reticulum. The expression pattern of ATL9 is positively correlated with basal defense responses against Golovinomyces cichoracearum, a biotrophic fungal pathogen. The basal levels of expression and the induction of ATL9 by chitin, in wild type plants, depends on the activity of NADPH oxidases suggesting that chitin-mediated defense response is NADPH oxidase dependent. Although ATL9 expression is not induced by treatment with known defense hormones (SA, JA or ET, full expression in response to chitin is compromised slightly in mutants where ET- or SA-dependent signaling is suppressed. Microarray analysis of the atl9 mutant revealed candidate genes that appear to act downstream of ATL9 in chitin-mediated defenses. These results hint at the complexity of chitin-mediated signaling and the potential interplay between elicitor-mediated signaling, signaling via known defense pathways and the oxidative burst.

Response of different genotypes of wheat, rice and black beans to anther, embryo and other tissue cultures

International Nuclear Information System (INIS)

Franco, E.; Amador, D.; Calderon, J.; Alvarez, G.; Alvarado, J.; Ramazzini, H.; Ramos, S.; Acuna, G.; Zuniga, B.

1996-01-01

The objective of the basic studies we have been conducting in our laboratory is to establish callus induction and in vitro plant regeneration protocols starting with several tissues of Guatemalan varieties of wheat (Triticum aesticum L.), rice (Oryza sativa L.) and especially black bean (Phaseolus vulgaris L.) in order to obtain disease resistance, earliness, and dwarf plants. Wheat anthers and immature embryos of varieties Patzun, Comalapa, Chocoyo, and Xequijel cultured in N 6 , Potato II, and MS basal media supplemented with auxin and cytokinin gave the best responses in callus induction and plant regeneration. Anthers and mature embryos of indica rice varieties Precozicta and Virginai, when cultured in MS, B 5 , N 6 , and Potato II basal media with different hormonal combinations gave a good response in callus induction. However, a satisfactory response in plant regeneration was not obtained. With black beans, when hypocotyls and mature embryos of black bean varieties Quinack Che and Parramos were cultured in MS basal medium supplemented with different concentrations of NAA and kinetin, more than 60% callus induction was produced. When Quinack Che calli were transferred to MS basal medium supplemented with 1 mg/l NAA plus 0.5 mg/l BAP, green points of regeneration were visible in these calli. (author). 34 refs, 28 tabs

JcDREB2, a Physic Nut AP2/ERF Gene, Alters Plant Growth and Salinity Stress Responses in Transgenic Rice.

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Tang, Yuehui; Liu, Kun; Zhang, Ju; Li, Xiaoli; Xu, Kedong; Zhang, Yi; Qi, Jing; Yu, Deshui; Wang, Jian; Li, Chengwei

2017-01-01

Transcription factors of the AP2/ERF family play important roles in plant growth, development, and responses to biotic and abiotic stresses. In this study, a physic nut AP2/ERF gene, JcDREB2 , was functionally characterized. Real-time PCR analysis revealed that JcDREB2 was expressed mainly in the leaf and could be induced by abscisic acid but suppressed by gibberellin (GA) and salt. Transient expression of a JcDREB2-YFP fusion protein in Arabidopsis protoplasts cells suggested that JcDREB2 is localized in the nucleus. Rice plants overexpressing JcDREB2 exhibited dwarf and GA-deficient phenotypes with shorter shoots and roots than those of wild-type plants. The dwarfism phenotype could be rescued by the application of exogenous GA 3 . The expression levels of GA biosynthetic genes including OsGA20ox1 , OsGA20ox2 , OsGA20ox4 , OsGA3ox2, OsCPS1 , OsKO2 , and OsKAO were significantly reduced in plants overexpressing JcDREB2 . Overexpression of JcDREB2 in rice increased sensitivity to salt stress. Increases in the expression levels of several salt-tolerance-related genes in response to salt stress were impaired in JcDREB2 -overexpressing plants. These results demonstrated not only that JcDREB2 influences GA metabolism, but also that it can participate in the regulation of the salt stress response in rice.

Role of transposon-derived small RNAs in the interplay between genomes and parasitic DNA in rice.

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Misuzu Nosaka

2012-09-01

Full Text Available RNA silencing is a defense system against "genomic parasites" such as transposable elements (TE, which are potentially harmful to host genomes. In plants, transcripts from TEs induce production of double-stranded RNAs (dsRNAs and are processed into small RNAs (small interfering RNAs, siRNAs that suppress TEs by RNA-directed DNA methylation. Thus, the majority of TEs are epigenetically silenced. On the other hand, most of the eukaryotic genome is composed of TEs and their remnants, suggesting that TEs have evolved countermeasures against host-mediated silencing. Under some circumstances, TEs can become active and increase in copy number. Knowledge is accumulating on the mechanisms of TE silencing by the host; however, the mechanisms by which TEs counteract silencing are poorly understood. Here, we show that a class of TEs in rice produces a microRNA (miRNA to suppress host silencing. Members of the microRNA820 (miR820 gene family are located within CACTA DNA transposons in rice and target a de novo DNA methyltransferase gene, OsDRM2, one of the components of epigenetic silencing. We confirmed that miR820 negatively regulates the expression of OsDRM2. In addition, we found that expression levels of various TEs are increased quite sensitively in response to decreased OsDRM2 expression and DNA methylation at TE loci. Furthermore, we found that the nucleotide sequence of miR820 and its recognition site within the target gene in some Oryza species have co-evolved to maintain their base-pairing ability. The co-evolution of these sequences provides evidence for the functionality of this regulation. Our results demonstrate how parasitic elements in the genome escape the host's defense machinery. Furthermore, our analysis of the regulation of OsDRM2 by miR820 sheds light on the action of transposon-derived small RNAs, not only as a defense mechanism for host genomes but also as a regulator of interactions between hosts and their parasitic elements.

Proteomic analysis of the defense response of wheat to the powdery mildew fungus, Blumeria graminis f. sp. tritici.

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Mandal, Md Siddikun Nabi; Fu, Ying; Zhang, Sheng; Ji, Wanquan

2014-12-01

Powdery mildew of wheat is caused by Blumeria graminis f. sp. tritici (Bgt). Although many wheat cultivars resistant to this disease have been developed, little is known about their resistance mechanisms. The aim of this study was to identify proteins showing changes in abundance during the resistance response of the wheat line N0308 infected by Bgt. In two-dimensional electrophoresis analyses, 45 spots on the gels showed significant changes in abundance at 24, 48, and 72 h after inoculation, as compared to non-inoculated plants. Of these 45 proteins, 44 were identified by mass spectrometry analysis using the NCBInr database of Triticum aestivum (26 spots) and closely related species in the Triticum genus (18 spots). These proteins were associated with the defense response, photosynthesis, metabolism, and other cellular processes in wheat. Most of the up-regulated proteins were identified as stress- and defense-related proteins. In particular, the product of a specific powdery mildew resistance gene (Pm3b and its homolog) and some other defense- and pathogenesis-related proteins were overexpressed. The resistance gene product mediates the immune response and coordinates other cellular processes during the resistance response to Bgt.

[Responses of rice-wheat rotation system in south Jiangsu to organic-inorganic compound fertilizers].

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Tian, Heng-Da; Zhang, Li; Zhang, Jian-Chao; Wang, Qiu-Jun; Xu, Da-Bing; Yibati, Halihashi; Xu, Jia-Le; Huang, Qi-Wei

2011-11-01

In 2006-2007, a field trial was conducted to study the effects of applying three kinds of organic-inorganic compound fertilizers [rapeseed cake compost plus inorganic fertilizers (RCC), pig manure compost plus inorganic fertilizers (PMC), and Chinese medicine residues plus inorganic fertilizers (CMC)] on the crop growth and nitrogen (N) use efficiency of rice-wheat rotation system in South Jiangsu. Grain yield of wheat and rice in the different fertilization treatments was significantly higher than the control (no fertilization). In treatments RCC, PMC and CMC, the wheat yield was 13.1%, 32.2% and 39.3% lower than that of the NPK compound fertilizer (CF, 6760 kg x hm(-2)), respectively, but the rice yield (8504-9449 kg x hm(-2)) was significantly higher than that (7919 kg x hm(-2)) of CF, with an increment of 7.4%-19.3%. In wheat season, the aboveground dry mass, N accumulation, and N use efficiency in treatments RCC, PMC, and CMC were lower than those of CF, but in rice season, these parameters were significantly higher than or as the same as CF. In sum, all the test three compound fertilizers had positive effects on the rice yield and its nitrogen use efficiency in the rice-wheat rotation system, being most significant for RCC.

Interacting signal pathways control defense gene expression in Arabidopsis in response to cell wall-degrading enzymes from Erwinia carotovora.

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Norman-Setterblad, C; Vidal, S; Palva, E T

2000-04-01

We have characterized the role of salicylic acid (SA)-independent defense signaling in Arabidopsis thaliana in response to the plant pathogen Erwinia carotovora subsp. carotovora. Use of pathway-specific target genes as well as signal mutants allowed us to elucidate the role and interactions of ethylene, jasmonic acid (JA), and SA signal pathways in this response. Gene expression studies suggest a central role for both ethylene and JA pathways in the regulation of defense gene expression triggered by the pathogen or by plant cell wall-degrading enzymes (CF) secreted by the pathogen. Our results suggest that ethylene and JA act in concert in this regulation. In addition, CF triggers another, strictly JA-mediated response inhibited by ethylene and SA. SA does not appear to have a major role in activating defense gene expression in response to CF. However, SA may have a dual role in controlling CF-induced gene expression, by enhancing the expression of genes synergistically induced by ethylene and JA and repressing genes induced by JA alone.

Low-temperature-induced expression of rice ureidoglycolate amidohydrolase is mediated by a C-repeat/dehydration-responsive element that specifically interacts with rice C-repeat-binding factor 3

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Juan eLi

2015-11-01

Full Text Available Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH, which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT but not abscisic acid- (ABA regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH. Series deletions revealed that a minimal region between -522 and -420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE element localized at position -434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily.

Bodily ownership modulation in defensive responses: physiological evidence in brain-damaged patients with pathological embodiment of other’s body parts

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Fossataro, C.; Gindri, P.; Mezzanato, T.; Pia, L.; Garbarini, F.

2016-01-01

Do conscious beliefs about the body affect defensive mechanisms within the body? To answer this question we took advantage from a monothematic delusion of bodily ownership, in which brain-damaged patients misidentify alien limbs as their own. We investigated whether the delusional belief that an alien hand is their own hand modulates a subcortical defensive response, such as the hand-blink reflex. The blink, dramatically increases when the threated hand is inside the defensive peripersonal-space of the face. In our between-subjects design, including patients and controls, the threat was brought near the face either by the own hand or by another person’s hand. Our results show an ownership-dependent modulation of the defensive response. In controls, as well as in the patients’ intact-side, the response enhancement is significantly greater when the threat was brought near the face by the own than by the alien hand. Crucially, in the patients’ affected-side (where the pathological embodiment occurs), the alien (embodied) hand elicited a response enhancement comparable to that found when the threat is brought near the face by the real hand. These findings suggest the existence of a mutual interaction between our conscious beliefs about the body and the physiological mechanisms within the body. PMID:27292285

Impacts of aerosol pollutant mitigation on lowland rice yields in China

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Zhang, Tianyi; Li, Tao; Yue, Xu; Yang, Xiaoguang

2017-10-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis and yields. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ a process-based modelling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. As a net effect, rice yields were estimated to significantly increase by 0.8%-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

Causes of variation among rice models in yield response to CO2 examined with Free-Air CO2 Enrichment and growth chamber experiments.

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Hasegawa, Toshihiro; Li, Tao; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Baker, Jeffrey; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fugice, Job; Fumoto, Tamon; Gaydon, Donald; Kumar, Soora Naresh; Lafarge, Tanguy; Marcaida Iii, Manuel; Masutomi, Yuji; Nakagawa, Hiroshi; Oriol, Philippe; Ruget, Françoise; Singh, Upendra; Tang, Liang; Tao, Fulu; Wakatsuki, Hitomi; Wallach, Daniel; Wang, Yulong; Wilson, Lloyd Ted; Yang, Lianxin; Yang, Yubin; Yoshida, Hiroe; Zhang, Zhao; Zhu, Jianguo

2017-11-01

The CO 2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO 2 ] (E-[CO 2 ]) by comparison to free-air CO 2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO 2 ] varied significantly among the rice models. The variation was not random: models that overestimated at one experiment simulated greater yield enhancements at the others. The variation was not associated with model structure or magnitude of photosynthetic response to E-[CO 2 ] but was significantly associated with the predictions of leaf area. This suggests that modelled secondary effects of E-[CO 2 ] on morphological development, primarily leaf area, are the sources of model uncertainty. Rice morphological development is conservative to carbon acquisition. Uncertainty will be reduced by incorporating this conservative nature of the morphological response to E-[CO 2 ] into the models. Nitrogen levels, particularly under limited situations, make the prediction more uncertain. Improving models to account for [CO 2 ] × N interactions is necessary to better evaluate management practices under climate change.

Lower responsiveness of canopy evapotranspiration rate than of leaf stomatal conductance to open-air CO2 elevation in rice.

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Shimono, Hiroyuki; Nakamura, Hirofumi; Hasegawa, Toshihiro; Okada, Masumi

2013-08-01

An elevated atmospheric CO2 concentration ([CO2 ]) can reduce stomatal conductance of leaves for most plant species, including rice (Oryza sativa L.). However, few studies have quantified seasonal changes in the effects of elevated [CO2 ] on canopy evapotranspiration, which integrates the response of stomatal conductance of individual leaves with other responses, such as leaf area expansion, changes in leaf surface temperature, and changes in developmental stages, in field conditions. We conducted a field experiment to measure seasonal changes in stomatal conductance of the uppermost leaves and in the evapotranspiration, transpiration, and evaporation rates using a lysimeter method. The study was conducted for flooded rice under open-air CO2 elevation. Stomatal conductance decreased by 27% under elevated [CO2 ], averaged throughout the growing season, and evapotranspiration decreased by an average of 5% during the same period. The decrease in daily evapotranspiration caused by elevated [CO2 ] was more significantly correlated with air temperature and leaf area index (LAI) rather than with other parameters of solar radiation, days after transplanting, vapor-pressure deficit and FAO reference evapotranspiration. This indicates that higher air temperatures, within the range from 16 to 27 °C, and a larger LAI, within the range from 0 to 4 m(2)  m(-2) , can increase the magnitude of the decrease in evapotranspiration rate caused by elevated [CO2 ]. The crop coefficient (i.e. the evapotranspiration rate divided by the FAO reference evapotranspiration rate) was 1.24 at ambient [CO2 ] and 1.17 at elevated [CO2 ]. This study provides the first direct measurement of the effects of elevated [CO2 ] on rice canopy evapotranspiration under open-air conditions using the lysimeter method, and the results will improve future predictions of water use in rice fields. © 2013 John Wiley & Sons Ltd.

Jasmonate signaling is activated in the very early stages of iron deficiency responses in rice roots.

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Kobayashi, Takanori; Itai, Reiko Nakanishi; Senoura, Takeshi; Oikawa, Takaya; Ishimaru, Yasuhiro; Ueda, Minoru; Nakanishi, Hiromi; Nishizawa, Naoko K

2016-07-01

Under low iron availability, plants induce the expression of various genes involved in iron uptake and translocation at the transcriptional level. This iron deficiency response is affected by various plant hormones, but the roles of jasmonates in this response are not well-known. We investigated the involvement of jasmonates in rice iron deficiency responses. High rates of jasmonate-inducible genes were induced during the very early stages of iron deficiency treatment in rice roots. Many jasmonate-inducible genes were also negatively regulated by the ubiquitin ligases OsHRZ1 and OsHRZ2 and positively regulated by the transcription factor IDEF1. Ten out of 35 genes involved in jasmonate biosynthesis and signaling were rapidly induced at 3 h of iron deficiency treatment, and this induction preceded that of known iron deficiency-inducible genes involved in iron uptake and translocation. Twelve genes involved in jasmonate biosynthesis and signaling were also upregulated in HRZ-knockdown roots. Endogenous concentrations of jasmonic acid and jasmonoyl isoleucine tended to be rapidly increased in roots in response to iron deficiency treatment, whereas these concentrations were higher in HRZ-knockdown roots under iron-sufficient conditions. Analysis of the jasmonate-deficient cpm2 mutant revealed that jasmonates repress the expression of many iron deficiency-inducible genes involved in iron uptake and translocation under iron sufficiency, but this repression is partly canceled under an early stage of iron deficiency. These results indicate that jasmonate signaling is activated during the very early stages of iron deficiency, which is partly regulated by IDEF1 and OsHRZs.

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

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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.

The endochitinase VDECH from Verticillium dahliae inhibits spore germination and activates plant defense responses

Science.gov (United States)

Chitinases function in the digestion of chitin molecules, which are present principally in insects and fungi. In plants, chitinase genes play important roles in defense, and their expression can be triggered in response to both biotic and abiotic stresses. In this study, we cloned and characterized ...

The US-Russia missile defense dialogue as a factor of the Russian defense policy

OpenAIRE

Dmitry Suslov

2013-01-01

To a big extent the Russian defense policy and, as a consequence, development of the Russian defense industrial complex, is determined by the prospects of the US missile defense policy and fate of the US-Russia negotiations in this area. As a cooperative solution seems improbable in the observable future, Russia plans to develop certain response measures of military nature, including creation of a new heavy ICBM, and to create its own missile defense by 2015. However, this policy does not see...

Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants

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Alejandra Moenne

2011-11-01

Full Text Available Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA, jasmonic acid (JA and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i Pathogenesis-Related (PR proteins with antifungal and antibacterial activities; (ii defense enzymes such as pheylalanine ammonia lyase (PAL and lipoxygenase (LOX which determine accumulation of phenylpropanoid compounds (PPCs and oxylipins with antiviral, antifugal and antibacterial activities and iii enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.

Broken rice kernels and the kinetics of rice hydration and texture during cooking.

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Saleh, Mohammed; Meullenet, Jean-Francois

2013-05-01

During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.

Effect of microcystins on root growth, oxidative response, and exudation of rice (Oryza sativa).

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Cao, Qing; Rediske, Richard R; Yao, Lei; Xie, Liqiang

2018-03-01

A 30 days indoor hydroponic experiment was carried out to evaluate the effect of microcystins (MCs) on rice root morphology and exudation, as well as bioaccumulation of MCs in rice. MCs were bioaccumulated in rice with the greatest concentrations being observed in the leaves (113.68μgg -1 Fresh weight (FW)) when exposed to 500μgL -1 MCs. Root activity at 500μgL -1 decreased 37%, compared to the control. MCs also induced disruption of the antioxidant system and lipid peroxidation in rice roots. Root growth was significantly inhibited by MCs. Root weight, length; surface area and volume were significantly decreased, as well as crown root number and lateral root number. After 30 days exposure to MCs, an increase was found in tartaric acid and malic acid while the other organic acids were not affected. Glycine, tyrosine, and glutamate were the only amino acids stimulated at MCs concentrations of 500μgL -1 . Similarly, dissolved organic carbon (DOC) and carbohydrate at 50 and 500μgL -1 treatments were significantly increased. The increase of DOC and carbohydrate in root exudates was due to rice root membrane permeability changes induced by MCs. Overall, this study indicated that MCs significantly inhibited rice root growth and affected root exudation. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

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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.

Integrated physiological, biochemical and molecular analysis identifies important traits and mechanisms associated with differential response of rice genotypes to elevated temperature

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Boghireddy eSailaja

2015-11-01

Full Text Available In changing climate, heat stress caused by high temperature poses a serious threat to rice cultivation. A multiple organizational analysis at physiological, biochemical and molecular level is required to fully understand the impact of elevated temperature in rice. This study was aimed at deciphering the elevated temperature response in eleven popular and mega rice cultivars widely grown in India. Physiological and biochemical traits specifically membrane thermostability (MTS, antioxidants, and photosynthesis were studied at vegetative and reproductive phases which were used to establish a correlation with grain yield under stress. Several useful traits in different genotypes were identified which will be important resource to develop high temperature tolerant rice cultivars. Interestingly, Nagina22 emerged as best performer in terms of yield as well as expression of physiological and biochemical traits at elevated temperature. It showed lesser relative injury, lesser reduction in chlorophyll content, increased super oxide dismutase, catalase and peroxidase activity, lesser reduction in net photosynthetic rate (PN, high transpiration rate (E and other photosynthetic/ fluorescence parameters contributing to least reduction in spikelet fertility and grain yield at elevated temperature. Further, expression of 14 genes including heat shock transcription factors and heat shock proteins was analyzed in Nagina22 (tolerant and Vandana (susceptible at flowering phase, strengthening the fact that N22 performs better at molecular level also during elevated temperature. This study shows that elevated temperature response is complex and involves multiple biological processes which are needed to be characterized to address the challenges of future climate extreme conditions.

Defatted flaxseed meal incorporated corn-rice flour blend based extruded product by response surface methodology.

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Ganorkar, Pravin M; Patel, Jhanvi M; Shah, Vrushti; Rangrej, Vihang V

2016-04-01

Considering the evidence of flaxseed and its defatted flaxseed meal (DFM) for human health benefits, response surface methodology (RSM) based on three level four factor central composite rotatable design (CCRD) was employed for the development of DFM incorporated corn - rice flour blend based extruded snack. The effect of DFM fortification (7.5-20 %), moisture content of feed (14-20 %, wb), extruder barrel temperature (115-135 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), overall acceptability (OAA) score and water solubility index (WSI) of extrudates were investigated using central composite rotatable design (CCRD). Significant regression models explained the effect of considered variables on all responses. DFM incorporation level was found to be most significant independent variable affecting on extrudates characteristics followed by extruder barrel temperature and then screw rpm. Feed moisture content did not affect extrudates characteristics. As DFM level increased (7.5 % to 20 %), ER and OAA value decreased. However, BS and WSI values were found to increase with increase in DFM level. Based on the defined criteria for numerical optimization, the combination for the production of DFM incorporated extruded snack with desired sensory attributes was achieved by incorporating 10 % DFM (replacing rice flour in flour blend) and by keeping 20 % moisture content, 312 screw rpm and 125 °C barrel temperature.

Responses of Rapid Viscoanalyzer Profile and Other Rice Grain Qualities to Exogenously Applied Plant Growth Regulators under High Day and High Night Temperatures.

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Shah Fahad

Full Text Available High-temperature stress degrades the grain quality of rice; nevertheless, the exogenous application of plant growth regulators (PGRs might alleviate the negative effects of high temperatures. In the present study, we investigated the responses of rice grain quality to exogenously applied PGRs under high day temperatures (HDT and high night temperatures (HNT under controlled conditions. Four different combinations of ascorbic acid (Vc, alpha-tocopherol (Ve, brassinosteroids (Br, methyl jasmonates (MeJA and triazoles (Tr were exogenously applied to two rice cultivars (IR-64 and Huanghuazhan prior to the high-temperature treatment. A Nothing applied Control (NAC was included for comparison. The results demonstrated that high-temperature stress was detrimental for grain appearance and milling qualities and that both HDT and HNT reduced the grain length, grain width, grain area, head rice percentage and milled rice percentage but increased the chalkiness percentage and percent area of endosperm chalkiness in both cultivars compared with ambient temperature (AT. Significantly higher grain breakdown, set back, consistence viscosity and gelatinization temperature, and significantly lower peak, trough and final viscosities were observed under high-temperature stress compared with AT. Thus, HNT was more devastating for grain quality than HDT. The exogenous application of PGRs ameliorated the adverse effects of high temperature in both rice cultivars, and Vc+Ve+MejA+Br was the best combination for both cultivars under high temperature stress.

Investigating the roles of MicroRNAs in biotic stress response induced by Rhizoctonia solani in rice

Energy Technology Data Exchange (ETDEWEB)

Syuhada, O. Nurfarahana; Kalaivani, N. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2014-09-03

Sheath blight disease, caused by Rhizoctonia solani 1802/KB was screened on two rice varieties, Oryza sativaindica cultivar MR219 and Oryza sativa indica cultivar UKMRC9. The disease symptom was severe in MR219 compared to UKMRC9. Total RNA from R. solani 1802/KB, infected rice leaves of MR219 and infected rice leaves of UKMRC9 were extracted using TRIzol reagent, purified and sent for small RNA sequencing. Three miRNA libraries were generated and analyzed. The libraries generated 65 805, 78 512 and 81 325 known miRNAs respectively. The structure of miRNA of these samples was predicted. The up-regulated and down-regulated of miRNAs target gene prediction and its target functions were discovered and were mainly related to the growth and development of metabolism, protein transport, transcriptional regulation, stress response, and hormone signaling and electron transfer. Sheath blight-induced differential expression of known miRNAs tends to targetMYB transcription factor, F-box proteins, NBS-LRR, leucine-rich repeat receptor protein kinases and zinc finger proteins. Detecting new miRNAs and measuring the expression profiles of known miRNAs is an important tasks required for a better understanding of various biological conditions. Therefore, further analysis using Gene Ontology Slim will be conducted to deduce some biological information from the datasets obtained.

Growth, photosynthesis and antioxidant responses of endophyte infected and non-infected rice under lead stress conditions.

Science.gov (United States)

Li, Xuemei; Bu, Ning; Li, Yueying; Ma, Lianju; Xin, Shigang; Zhang, Lihong

2012-04-30

An endophytic fungus was tested in rice (Oryza sativa L.) exposed to four levels of lead (Pb) stress (0, 50, 100 and 200 μM) to assess effects on plant growth, photosynthesis and antioxidant enzyme activity. Under Pb stress conditions, endophyte-infected seedlings had greater shoot length but lower root length compared to non-infected controls, and endophyte-infected seedlings had greater dry weight in the 50 and 100 μM Pb treatments. Under Pb stress conditions, chlorophyll and carotenoid levels were significantly higher in the endophyte-infected seedlings. Net photosynthetic rate, transpiration rate and water use efficiency were significantly higher in endophyte-infected seedlings in the 50 and 100 μM Pb treatments. In addition, chlorophyll fluorescence parameters Fv/Fm and Fv/Fo were higher in the infected seedlings compared to the non-infected seedlings under Pb stress. Malondialdehyde accumulation was induced by Pb stress, and it was present in higher concentration in non-infected seedlings under higher concentrations of Pb (100 and 200 μM). Antioxidant activity was either higher or unchanged in the infected seedlings due to responses to the different Pb concentrations. These results suggest that the endophytic fungus improved rice growth under moderate Pb levels by enhancing photosynthesis and antioxidant activity relative to non-infected rice. Copyright © 2012 Elsevier B.V. All rights reserved.

Bacillus amyloliquefaciens Confers Tolerance to Various Abiotic Stresses and Modulates Plant Response to Phytohormones through Osmoprotection and Gene Expression Regulation in Rice

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Shalini Tiwari

2017-08-01

Full Text Available Being sessile in nature, plants have to withstand various adverse environmental stress conditions including both biotic and abiotic stresses. Comparatively, abiotic stresses such as drought, salinity, high temperature, and cold pose major threat to agriculture by negatively impacting plant growth and yield worldwide. Rice is one of the most widely consumed staple cereals across the globe, the production and productivity of which is also severely affected by different abiotic stresses. Therefore, several crop improvement programs are directed toward developing stress tolerant rice cultivars either through marker assisted breeding or transgenic technology. Alternatively, some known rhizospheric competent bacteria are also known to improve plant growth during abiotic stresses. A plant growth promoting rhizobacteria (PGPR, Bacillus amyloliquefaciens NBRI-SN13 (SN13 was previously reported by our lab to confer salt stress tolerance to rice seedlings. However, the present study investigates the role of SN13 in ameliorating various abiotic stresses such as salt, drought, desiccation, heat, cold, and freezing on a popular rice cv. Saryu-52 under hydroponic growth conditions. Apart from this, seedlings were also exogenously supplied with abscisic acid (ABA, salicylic acid (SA, jasmonic acid (JA and ethephon (ET to study the role of SN13 in phytohormone-induced stress tolerance as well as its role in abiotic and biotic stress cross-talk. All abiotic stresses and phytohormone treatments significantly affected various physiological and biochemical parameters like membrane integrity and osmolyte accumulation. SN13 also positively modulated stress-responsive gene expressions under various abiotic stresses and phytohormone treatments suggesting its multifaceted role in cross-talk among stresses and phytohormones in response to PGPR. To the best of our knowledge, this is the first report on detailed analysis of plant growth promotion and stress alleviation by a

Plant defense against insect herbivores

DEFF Research Database (Denmark)

Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

2013-01-01

, defense compounds. These bioactive specialized plant defense compounds may repel or intoxicate insects, while defense proteins often interfere with their digestion. Volatiles are released upon herbivory to repel herbivores, attract predators or for communication between leaves or plants, and to induce......Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar...... defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects...

Comparative Transcriptome Analysis of Shoots and Roots of TNG67 and TCN1 Rice Seedlings under Cold Stress and Following Subsequent Recovery: Insights into Metabolic Pathways, Phytohormones, and Transcription Factors.

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Yun-Wei Yang

Full Text Available Cold stress affects rice growth, quality and yield. The investigation of genome-wide gene expression is important for understanding cold stress tolerance in rice. We performed comparative transcriptome analysis of the shoots and roots of 2 rice seedlings (TNG67, cold-tolerant; and TCN1, cold-sensitive in response to low temperatures and restoration of normal temperatures following cold exposure. TNG67 tolerated cold stress via rapid alterations in gene expression and the re-establishment of homeostasis, whereas the opposite was observed in TCN1, especially after subsequent recovery. Gene ontology and pathway analyses revealed that cold stress substantially regulated the expression of genes involved in protein metabolism, modification, translation, stress responses, and cell death. TNG67 takes advantage of energy-saving and recycling resources to more efficiently synthesize metabolites compared with TCN1 during adjustment to cold stress. During recovery, expression of OsRR4 type-A response regulators was upregulated in TNG67 shoots, whereas that of genes involved in oxidative stress, chemical stimuli and carbohydrate metabolic processes was downregulated in TCN1. Expression of genes related to protein metabolism, modification, folding and defense responses was upregulated in TNG67 but not in TCN1 roots. In addition, abscisic acid (ABA-, polyamine-, auxin- and jasmonic acid (JA-related genes were preferentially regulated in TNG67 shoots and roots and were closely associated with cold stress tolerance. The TFs AP2/ERF were predominantly expressed in the shoots and roots of both TNG67 and TCN1. The TNG67-preferred TFs which express in shoot or root, such as OsIAA23, SNAC2, OsWRKY1v2, 24, 53, 71, HMGB, OsbHLH and OsMyb, may be good candidates for cold stress tolerance-related genes in rice. Our findings highlight important alterations in the expression of cold-tolerant genes, metabolic pathways, and hormone-related and TF-encoding genes in TNG67 rice

The interaction of strigolactones with abscisic acid during the drought response in rice

KAUST Repository

Haider, Imran; Andreo-Jimenez, Beatriz; Bruno, Mark; Bimbo, Andrea; Floková , Kristý na; Abuauf, Haneen Waleed Hamza; Otang Ntui, Valentine; Guo, Xiujie; Charnikhova, Tatsiana; Al-Babili, Salim; Bouwmeester, Harro J; Ruyter-Spira, Carolien

2018-01-01

Both strigolactones (SLs) and abscisic acid (ABA) biosynthetically originate from carotenoids. Considering their common origin, the interaction of these two hormones at the biosynthetic and/or regulatory level may be anticipated. Here, we show in rice that drought simultaneously induces SL production in the root, and ABA production and the expression of SL biosynthetic genes in the shoot. Under control conditions, the ABA concentration was higher in shoots of the SL biosynthetic rice mutants dwarf10 (d10) and d17 than in wild-type plants, while a similar trend was observed for SL-perception mutant d3. These differences were enhanced under drought. However, drought did not result in an increase in leaf ABA content in rice mutant line d27, carrying a mutation in the gene encoding the first committed enzyme in SL biosynthesis, to the same extent as in the other SL mutants and the wild-type. Accordingly, d10, d17 and d3 lines were more drought tolerant than wild-type plants, whereas d27 displayed decreased tolerance. Finally, over-expression of OsD27 in rice resulted in increased levels of ABA when compared with wild-type plants. We conclude that the SL and ABA pathways are connected with each other through D27, which is playing a crucial role in determining ABA and SL content in rice.

The interaction of strigolactones with abscisic acid during the drought response in rice

KAUST Repository

Haider, Imran

2018-03-09

Both strigolactones (SLs) and abscisic acid (ABA) biosynthetically originate from carotenoids. Considering their common origin, the interaction of these two hormones at the biosynthetic and/or regulatory level may be anticipated. Here, we show in rice that drought simultaneously induces SL production in the root, and ABA production and the expression of SL biosynthetic genes in the shoot. Under control conditions, the ABA concentration was higher in shoots of the SL biosynthetic rice mutants dwarf10 (d10) and d17 than in wild-type plants, while a similar trend was observed for SL-perception mutant d3. These differences were enhanced under drought. However, drought did not result in an increase in leaf ABA content in rice mutant line d27, carrying a mutation in the gene encoding the first committed enzyme in SL biosynthesis, to the same extent as in the other SL mutants and the wild-type. Accordingly, d10, d17 and d3 lines were more drought tolerant than wild-type plants, whereas d27 displayed decreased tolerance. Finally, over-expression of OsD27 in rice resulted in increased levels of ABA when compared with wild-type plants. We conclude that the SL and ABA pathways are connected with each other through D27, which is playing a crucial role in determining ABA and SL content in rice.

32 CFR 13.3 - Office of the Chief Defense Counsel.

Science.gov (United States)

2010-07-01

... COMMISSIONS RESPONSIBILITIES OF THE CHIEF DEFENSE COUNSEL, DETAILED DEFENSE COUNSEL, AND CIVILIAN DEFENSE... II of the Affidavit And Agreement By Civilian Defense Counsel at Appendix B to 32 CFR part 14. (5... incur confidentiality obligations in the context of fulfilling their supervisory responsibilities with...

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)

A cell wall-degrading esterase of Xanthomonas oryzae requires a unique substrate recognition module for pathogenesis on rice.

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Aparna, Gudlur; Chatterjee, Avradip; Sonti, Ramesh V; Sankaranarayanan, Rajan

2009-06-01

Xanthomonas oryzae pv oryzae (Xoo) causes bacterial blight, a serious disease of rice (Oryza sativa). LipA is a secretory virulence factor of Xoo, implicated in degradation of rice cell walls and the concomitant elicitation of innate immune responses, such as callose deposition and programmed cell death. Here, we present the high-resolution structural characterization of LipA that reveals an all-helical ligand binding module as a distinct functional attachment to the canonical hydrolase catalytic domain. We demonstrate that the enzyme binds to a glycoside ligand through a rigid pocket comprising distinct carbohydrate-specific and acyl chain recognition sites where the catalytic triad is situated 15 A from the anchored carbohydrate. Point mutations disrupting the carbohydrate anchor site or blocking the pocket, even at a considerable distance from the enzyme active site, can abrogate in planta LipA function, exemplified by loss of both virulence and the ability to elicit host defense responses. A high conservation of the module across genus Xanthomonas emphasizes the significance of this unique plant cell wall-degrading function for this important group of plant pathogenic bacteria. A comparison with the related structural families illustrates how a typical lipase is recruited to act on plant cell walls to promote virulence, thus providing a remarkable example of the emergence of novel functions around existing scaffolds for increased proficiency of pathogenesis during pathogen-plant coevolution.

Silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.

Science.gov (United States)

Zarate, Sonia I; Kempema, Louisa A; Walling, Linda L

2007-02-01

The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF.

Kinetic parameters of silicon uptake by rice cultivars

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Priscila Oliveira Martins

2012-02-01

Full Text Available Silicon is considered an important chemical element for rice, because it can improve tolerance to biotic and abiotic stress. However, in many situations no positive effect of silicon was observed, probably due to genetic factors. The objective of this research was to monitor Si uptake kinetics and identify responses of rice cultivars in terms of Si uptake capacity and use. The experiment was carried out in a greenhouse of the São Paulo State University (UNESP, Brazil. The experiment was arranged in a completely randomized, factorial design with three replications. that consisted of two rice cultivars and two Si levels. Kinetic parameters (Vmax, Km, and Cmin, root morphology variables, dry matter yield, Si accumulation and levels in shoots and roots, uptake efficiency, utilization efficiency, and root/shoot ratio were evaluated. Higher Si concentrations in the nutrient solution did not increase rice dry matter. The development of the low-affinity silicon uptake system of the rice cultivar 'Caiapó' was better than of 'Maravilha'.

RiceAtlas, a spatial database of global rice calendars and production.

Science.gov (United States)

Laborte, Alice G; Gutierrez, Mary Anne; Balanza, Jane Girly; Saito, Kazuki; Zwart, Sander J; Boschetti, Mirco; Murty, M V R; Villano, Lorena; Aunario, Jorrel Khalil; Reinke, Russell; Koo, Jawoo; Hijmans, Robert J; Nelson, Andrew

2017-05-30

Knowing where, when, and how much rice is planted and harvested is crucial information for understanding the effects of policy, trade, and global and technological change on food security. We developed RiceAtlas, a spatial database on the seasonal distribution of the world's rice production. It consists of data on rice planting and harvesting dates by growing season and estimates of monthly production for all rice-producing countries. Sources used for planting and harvesting dates include global and regional databases, national publications, online reports, and expert knowledge. Monthly production data were estimated based on annual or seasonal production statistics, and planting and harvesting dates. RiceAtlas has 2,725 spatial units. Compared with available global crop calendars, RiceAtlas is nearly ten times more spatially detailed and has nearly seven times more spatial units, with at least two seasons of calendar data, making RiceAtlas the most comprehensive and detailed spatial database on rice calendar and production.

Golden Rice is an effective source of vitamin A.

Science.gov (United States)

Tang, Guangwen; Qin, Jian; Dolnikowski, Gregory G; Russell, Robert M; Grusak, Michael A

2009-06-01

Genetically engineered "Golden Rice" contains up to 35 microg beta-carotene per gram of rice. It is important to determine the vitamin A equivalency of Golden Rice beta-carotene to project the potential effect of this biofortified grain in rice-consuming populations that commonly exhibit low vitamin A status. The objective was to determine the vitamin A value of intrinsically labeled dietary Golden Rice in humans. Golden Rice plants were grown hydroponically with heavy water (deuterium oxide) to generate deuterium-labeled [2H]beta-carotene in the rice grains. Golden Rice servings of 65-98 g (130-200 g cooked rice) containing 0.99-1.53 mg beta-carotene were fed to 5 healthy adult volunteers (3 women and 2 men) with 10 g butter. A reference dose of [13C10]retinyl acetate (0.4-1.0 mg) in oil was given to each volunteer 1 wk before ingestion of the Golden Rice dose. Blood samples were collected over 36 d. Our results showed that the mean (+/-SD) area under the curve for the total serum response to [2H]retinol was 39.9 +/- 20.7 microg x d after the Golden Rice dose. Compared with that of the [13C10]retinyl acetate reference dose (84.7 +/- 34.6 microg x d), Golden Rice beta-carotene provided 0.24-0.94 mg retinol. Thus, the conversion factor of Golden Rice beta-carotene to retinol is 3.8 +/- 1.7 to 1 with a range of 1.9-6.4 to 1 by weight, or 2.0 +/- 0.9 to 1 with a range of 1.0-3.4 to 1 by moles. Beta-carotene derived from Golden Rice is effectively converted to vitamin A in humans. This trial was registered at clinicaltrials.gov as NCT00680355.

The dynamic changes of the plasma membrane proteins and the protective roles of nitric oxide in rice subjected to heavy metal cadmium stress

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Liming eYang

2016-02-01

Full Text Available The heavy metal cadmium is a common environmental contaminant in soils and has adverse effects on crop growth and development. The signaling processes in plants that initiate cellular responses to environmental stress have been shown to be located in the plasma membrane (PM. A better understanding of the PM proteome in response to environmental stress might provide new insights for improving stress-tolerant crops. Nitric oxide (NO is reported to be involved in the plant response to cadmium (Cd stress. To further investigate how NO modulates protein changes in the plasma membrane during Cd stress, a quantitative proteomics approach based on isobaric tags for relative and absolute quantification (iTRAQ was used to identify differentially regulated proteins from the rice plasma membrane after Cd or Cd and NO treatment. Sixty-six differentially expressed proteins were identified, of which, many function as transporters, ATPases, kinases, metabolic enzymes, phosphatases and phospholipases. Among these, the abundance of phospholipase D (PLD was altered substantially after the treatment of both Cd and Cd and NO. Transient expression of the PLD fused with green fluorescent peptide (GFP in rice protoplasts showed that the Cd and NO treatment promoted the accumulation of PLD in the plasma membrane. Addition of NO also enhanced Cd-induced PLD activity and the accumulation of phosphatidic acid (PA produced through PLD activity. Meanwhile, NO elevated the activities of antioxidant enzymes and caused the accumulation of glutathione both which function to reduce Cd-induced H2O2 accumulation. Taken together, we suggest that NO signaling is associated with the accumulation of antioxidant enzymes, glutathione and PA which increases cadmium tolerance in rice via the antioxidant defense system.

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

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Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

2017-01-01

Silicon (Si) is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties. PMID:28191468

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

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Mahbod Sahebi

2017-01-01

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

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

Science.gov (United States)

Sahebi, Mahbod; Hanafi, Mohamed M; Rafii, M Y; Azizi, Parisa; Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

2017-01-01

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

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.

Neonicotinoid insecticides induce salicylate-associated plant defense responses

Science.gov (United States)

Ford, Kevin A.; Casida, John E.; Chandran, Divya; Gulevich, Alexander G.; Okrent, Rachel A.; Durkin, Kathleen A.; Sarpong, Richmond; Bunnelle, Eric M.; Wildermuth, Mary C.

2010-01-01

Neonicotinoid insecticides control crop pests based on their action as agonists at the insect nicotinic acetylcholine receptor, which accepts chloropyridinyl- and chlorothiazolyl-analogs almost equally well. In some cases, these compounds have also been reported to enhance plant vigor and (a)biotic stress tolerance, independent of their insecticidal function. However, this mode of action has not been defined. Using Arabidopsis thaliana, we show that the neonicotinoid compounds, imidacloprid (IMI) and clothianidin (CLO), via their 6-chloropyridinyl-3-carboxylic acid and 2-chlorothiazolyl-5-carboxylic acid metabolites, respectively, induce salicylic acid (SA)-associated plant responses. SA is a phytohormone best known for its role in plant defense against pathogens and as an inducer of systemic acquired resistance; however, it can also modulate abiotic stress responses. These neonicotinoids effect a similar global transcriptional response to that of SA, including genes involved in (a)biotic stress response. Furthermore, similar to SA, IMI and CLO induce systemic acquired resistance, resulting in reduced growth of a powdery mildew pathogen. The action of CLO induces the endogenous synthesis of SA via the SA biosynthetic enzyme ICS1, with ICS1 required for CLO-induced accumulation of SA, expression of the SA marker PR1, and fully enhanced resistance to powdery mildew. In contrast, the action of IMI does not induce endogenous synthesis of SA. Instead, IMI is further bioactivated to 6-chloro-2-hydroxypyridinyl-3-carboxylic acid, which is shown here to be a potent inducer of PR1 and inhibitor of SA-sensitive enzymes. Thus, via different mechanisms, these chloropyridinyl- and chlorothiazolyl-neonicotinoids induce SA responses associated with enhanced stress tolerance. PMID:20876120

Temperatures and the growth and development of maize and rice

DEFF Research Database (Denmark)

Sánchez, Berta; Rasmussen, Anton; Porter, John Roy

2014-01-01

and maize crop responses to temperature in different, but consistent, phenological phases and development stages. A literature review and data compilation of around 140 scientific articles have determined the key temperature thresholds and response to extreme temperature effects for rice and maize...... defined in all three crops. Anthesis and ripening are the most sensitive temperature stages in rice as well as in wheat and maize. We call for further experimental studies of the effects of transgressing threshold temperatures so such responses can be included into crop impact and adaptation models....

Analysis of Recombinant Proteins in Transgenic Rice Seeds: Identity, Localization, Tolerance to Digestion, and Plant Stress Response.

Science.gov (United States)

Wakasa, Yuhya; Takaiwa, Fumio

2016-01-01

Rice seeds are an ideal production platform for high-value recombinant proteins in terms of economy, scalability, safety, and stability. Strategies for the expression of large amounts of recombinant proteins in rice seeds have been established in the past decade and transgenic rice seeds that accumulate recombinant products such as bioactive peptides and proteins, which promote the health and quality of life of humans, have been generated in many laboratories worldwide. One of the most important advantages is the potential for direct oral delivery of transgenic rice seeds without the need for recombinant protein purification (downstream processing), which has been attributed to the high expression levels of recombinant products. Transgenic rice will be beneficial as a delivery system for pharmaceuticals and nutraceuticals in the future. This chapter introduces the strategy for producing recombinant protein in the edible part (endosperm) of the rice grain and describes methods for the analysis of transgenic rice seeds in detail.

Spatially distinct response of rice yield to autonomous adaptation under the CMIP5 multi-model projections

Science.gov (United States)

Shin, Yonghee; Lee, Eun-Jeong; Im, Eun-Soon; Jung, Il-Won

2017-02-01

Rice ( Oryza sativa L.) is a very important staple crop, as it feeds more than half of the world's population. Numerous studies have focused on the negative impacts of climate change on rice production. However, there is little debate on which region of the world is more vulnerable to climate change and how adaptation to this change can mitigate the negative impacts on rice production. We investigated the impacts of climate change on rice yield, based on simulations combining a global crop model, M-GAZE, and Coupled Model Intercomparison Project Phase 5 (CMIP5) multi-model projections. Our focus was the impact of mitigating emission forcings (representative concentration pathway RCP 4.5 vs. RCP 8.5) and autonomous adaptation (i.e., changing crop variety and planting date) on rice yield. In general, our results showed that climate change due to anthropogenic warming leads to a significant reduction in rice yield. However, autonomous adaptation provides the potential to reduce the negative impact of global warming on rice yields in a spatially distinct manner. The adaptation was less beneficial for countries located at a low latitude (e.g., Cambodia, Thailand, Brazil) compared to mid-latitude countries (e.g., USA, China, Pakistan), as regional climates at the lower latitudes are already near the upper temperature thresholds for acceptable rice growth. These findings suggest that the socioeconomic effects from rice production in lowlatitude countries can be highly vulnerable to anthropogenic global warming. Therefore, these countries need to be accountable to develop transformative adaptation strategies, such as adopting (or developing) heat-tolerant varieties, and/or improve irrigation systems and fertilizer use efficiency.

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

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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

Making Rice Production More Environmentally-Friendly

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Norman Uphoff

2016-05-01

Full Text Available Irrigated rice production is one of the most essential agricultural activities for sustaining our global population, and at the same time, one of the agricultural sectors considered most eco-unfriendly. This is because it consumes a larger share of available freshwater resources, competing with varied ecosystems as well as other economic sectors; its paddy fields are responsible for significant emission of greenhouse gases; and the reliance on chemical fertilizers and various agrochemicals contributes to pollution of soils and water systems. These stresses on soils, hydrology and atmosphere are actually not necessary for rice production, which can be increased by modifying agronomic practices though more agroecologically-sound management practices. These, combined under the rubric of the System of Rice Intensification (SRI, can reduce requirements of irrigation water, chemical fertilizer and agrochemicals while increasing paddy yields and farmer’s net incomes. Here we discuss how irrigated rice production can be made more eco-friendly for the benefit of farmers, consumers and the environment. This is achieved by introducing practices that improve the growth and functioning of rice plants’ root systems and enhance the abundance, diversity and activity of beneficial soil organisms that live around plant roots and within the plants themselves as symbiotic endophytes.

Physiological and Biochemical Responses of Growing Rats Fed Irradiated Full-Fat Rice Bran

International Nuclear Information System (INIS)

EL-Niely, H.F.G.

2006-01-01

Raw and irradiated full-fat rice bran at dose levels of 10, 15, 20 and 25 kGy were used in the diets of growing rats to evaluate their effect on plasma and liver lipid profile. Comparison was also done with the use of a standard casein diet. After 49 days of feeding trail, food intake and wt gain were found to be highest with rats received casein diet in comparison with those fed on rice bran diets. Raw and irradiated full-fat rice bran diets, fed to rats caused a significant reduction in the level of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-c), while a significant elevation in the level of high-density lipoprotein cholesterol (HDL-c) in plasma was recorded compared to those fed on casein diet. Also, similar changes were observed in liver. There was a significant increase in plasma and liver HDL-c/ TC ratio and LDL-c/ HDL-c ratio. Relative liver wt of rats fed on raw and irradiated full-fat rice brain up to 25 kGy was lower compared to those fed on control diet (casein diet). The casein group had the highest total plasma and liver total protein (TP) compared to the other experimental groups. Among the experimental groups, raw and processed full-fat rice brain up to 25 kGy, induced no significant effect on TP content of plasma and liver

Rice production in relation to soil quality under different rice-based cropping systems

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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

Using ORYZA2000 to model cold rice yield response to climate change in the Heilongjiang province, China

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Jingting Zhang

2015-08-01

Full Text Available Rice (Oryza sativa L. is one of the most important staple crops in China. Increasing atmospheric greenhouse gas concentrations and associated climate change may greatly affect rice production. We assessed the potential impacts of climate change on cold rice production in the Heilongjiang province, one of China's most important rice production regions. Data for a baseline period (1961–1990 and the period 2010–2050 in A2 and B2 scenarios were used as input to drive the rice model ORYZA2000 with and without accounting for the effects of increasing atmospheric CO2 concentration. The results indicate that mean, maximum, and minimum temperature during the rice growing season, in the future period considered, would increase by 1.8 °C under the A2 scenario and by 2.2 °C under the B2 scenario compared with those in the baseline. The rate of change in average maximum and minimum temperatures would increase by 0.6 °C per 10-year period under the A2 scenario and by 0.4 °C per 10-year period under the B2 scenario. Precipitation would increase slightly in the rice growing season over the next 40 years. The rice growing season would be shortened and the yield would increase in most areas in the Heilongjiang province. Without accounting for CO2 effect, the rice growing season in the period 2010–2050 would be shortened by 4.7 and 5.8 days, and rice yields would increase by 11.9% and 7.9%, under the A2 and B2 scenarios, respectively. Areas with simulated rice yield increases greater than 30.0% were in the Xiaoxing'an Mountain region. The simulation indicated a decrease in yield of less than 15% in the southwestern Songnen Plain. The rate of change in simulated rice yield was 5.0% and 2.5% per 10 years under the A2 and B2 scenarios, respectively. When CO2 effect was accounted for, rice yield increased by 44.5% and 31.3% under the A2 and B2 scenarios, respectively. The areas of increasing yield were sharply expanded. The area of decreasing yield in the

RPAN: rice pan-genome browser for ∼3000 rice genomes.

Science.gov (United States)

Sun, Chen; Hu, Zhiqiang; Zheng, Tianqing; Lu, Kuangchen; Zhao, Yue; Wang, Wensheng; Shi, Jianxin; Wang, Chunchao; Lu, Jinyuan; Zhang, Dabing; Li, Zhikang; Wei, Chaochun

2017-01-25

A pan-genome is the union of the gene sets of all the individuals of a clade or a species and it provides a new dimension of genome complexity with the presence/absence variations (PAVs) of genes among these genomes. With the progress of sequencing technologies, pan-genome study is becoming affordable for eukaryotes with large-sized genomes. The Asian cultivated rice, Oryza sativa L., is one of the major food sources for the world and a model organism in plant biology. Recently, the 3000 Rice Genome Project (3K RGP) sequenced more than 3000 rice genomes with a mean sequencing depth of 14.3×, which provided a tremendous resource for rice research. In this paper, we present a genome browser, Rice Pan-genome Browser (RPAN), as a tool to search and visualize the rice pan-genome derived from 3K RGP. RPAN contains a database of the basic information of 3010 rice accessions, including genomic sequences, gene annotations, PAV information and gene expression data of the rice pan-genome. At least 12 000 novel genes absent in the reference genome were included. RPAN also provides multiple search and visualization functions. RPAN can be a rich resource for rice biology and rice breeding. It is available at http://cgm.sjtu.edu.cn/3kricedb/ or http://www.rmbreeding.cn/pan3k. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Physiological investigation of C4-phosphoenolpyruvate-carboxylase-introduced rice line shows that sucrose metabolism is involved in the improved drought tolerance.

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Zhang, Chen; Li, Xia; He, Yafei; Zhang, Jinfei; Yan, Ting; Liu, Xiaolong

2017-06-01

We compared the drought tolerance of wild-type (WT) and transgenic rice plants (PC) over-expressing the maize C 4 PEPC gene, which encodes phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) gene, and evaluated the roles of saccharide and sugar-related enzymes in the drought response. Pot-grown seedlings were subjected to real drought conditions outdoors, and the yield components were compared between PC and untransformed wild-type (WT) plants. The stable yield from PC plants was associated with higher net photosynthetic rate under the real drought treatment. The physiological characters of WT and PC seedlings under a simulated drought treatment (25% (w/v) polyethylene glycol-6000 for 3 h; PEG 6000 treatment) were analyzed in detail for the early response of drought. The relative water content was higher in PC than in WT, and PEPC activity and the C 4 -PEPC transcript level in PC were elevated under the simulated drought conditions. The endogenous saccharide responses also differed between PC and WT under simulated drought stress. The higher sugar decomposition rate in PC than in WT under drought analog stress was related to the increased activities of sucrose phosphate synthase, sucrose synthase, acid invertase, and neutral invertase, increased transcript levels of VIN1, CIN1, NIN1, SUT2, SUT4, and SUT5, and increased activities of superoxide dismutase and peroxidase in the leaves. The greater antioxidant defense capacity of PC and its relationship with saccharide metabolism was one of the reasons for the improved drought tolerance. In conclusion, PEPC effectively alleviated oxidative damage and enhanced the drought tolerance in rice plants, which were more related to the increase of the endogenous saccharide decomposition. These findings show that components of C 4 photosynthesis can be used to increase the yield of rice under drought conditions. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Rice-arsenate interactions in hydroponics: whole genome transcriptional analysis.

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Norton, Gareth J; Lou-Hing, Daniel E; Meharg, Andrew A; Price, Adam H

2008-01-01

Rice (Oryza sativa) varieties that are arsenate-tolerant (Bala) and -sensitive (Azucena) were used to conduct a transcriptome analysis of the response of rice seedlings to sodium arsenate (AsV) in hydroponic solution. RNA extracted from the roots of three replicate experiments of plants grown for 1 week in phosphate-free nutrient with or without 13.3 muM AsV was used to challenge the Affymetrix (52K) GeneChip Rice Genome array. A total of 576 probe sets were significantly up-regulated at least 2-fold in both varieties, whereas 622 were down-regulated. Ontological classification is presented. As expected, a large number of transcription factors, stress proteins, and transporters demonstrated differential expression. Striking is the lack of response of classic oxidative stress-responsive genes or phytochelatin synthases/synthatases. However, the large number of responses from genes involved in glutathione synthesis, metabolism, and transport suggests that glutathione conjugation and arsenate methylation may be important biochemical responses to arsenate challenge. In this report, no attempt is made to dissect differences in the response of the tolerant and sensitive variety, but analysis in a companion article will link gene expression to the known tolerance loci available in the BalaxAzucena mapping population.

Defense radioactive waste management

International Nuclear Information System (INIS)

Hindman, T.B. Jr.

1988-01-01

The Office of Defense Programs (DP), U.S. Department of Energy, is responsible for the production of nuclear weapons and materials for national defense. Pursuant to this mission, DP operates a large industrial complex that employs over 60,000 people at various installations across the country. As a byproduct of their activities, these installations generate radioactive, hazardous, or mixed wastes that must be managed in a safe and cost-effective manner in compliance with all applicable Federal and STate environmental requirements. At the Federal level such requirements derive primarily from the Atomic Energy Act, the Resource Conservation and Recovery Act (RCRA), the comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Superfund Amendments and Reauthorization Act (SARA). Responsibility for DP activities in connection with the disposal of defense wastes is consolidated within the Office of Defense Waste and Transportation Management (DWTM). This paper discusses these activities which consist of five principal elements: the environmental restoration of inactive DP facilities and sites, the processing storage and disposal of wastes associated with ongoing operations at active DP facilities, research and development directed toward the long-term disposal of radioactive, hazardous, mixed wastes, technology development directly supporting regulatory compliance, and the development of policies, procedures, and technologies for assuring the safe transportation of radioactive and hazardous materials

Analysis of rice purchase decision on rice consumer in Bandung city

Science.gov (United States)

Kusno, K.; Imannurdin, A.; Syamsiyah, N.; Djuwendah, E.

2018-03-01

This study was conducted at three kinds of purchase location which were traditional market, rice kiosk, and supermarket in Bandung City, with survey data of 108 respondents which were selected by systematic random sampling. The aim of this study is to (1) identify consumer characteristics, (2) identify which atribute is considered by consumer in buying rice, and (3) analyze the relationship between purchase decision and income class. Data were analyzed by descriptive analysis and Chi Square test. The results showed most consumers in the traditional market were middle-educated and lower middle-income, at the rice kiosk, the consumer were generally middle-educated and middle-income, and in the supermarkets, the majority were high-educated and upper middle-income consumers. “Kepulenan” be the first priority of most consumers, but for the lower-middle class, the main priority was price. Thus, in case of scarcity and rice price increase, the government should immediately arrange market operations which targeting to lower-middle class consumers. There was a significant relationship between (1) the quality of rice consumed, (2) the frequency of rice purchase per month, and (3) attitudes toward rice price increase; each with the income class. Although the price of rice increase, consumers of middle and upper-middle were remain loyal to the quality of rice they consumed. This indicates rice market in Bandung city is an ideal market for premium rice so that traders and producers are expected to maintain the quality of rice, such as keep using superior seeds and applying good cultivation based on Good Agricultural Practice (GAP) rules.

Influence of rice black streaked dwarf virus on the ecological fitness of non-vector planthopper Nilaparvata lugens (Hemiptera: Delphacidae).

Science.gov (United States)

Xu, Hong-Xing; He, Xiao-Chan; Zheng, Xu-Song; Yang, Ya-Jun; Lu, Zhong-Xian

2014-08-01

Rice black streak dwarf virus (RBSDV) is transmitted by the small brown planthopper (SBPH), Laodelphax striatellus (Fallen). Non-vector rice brown planthopper (BPH), Nilaparvata lugens (Stål), shares the same host rice plants with SBPH in paddy fields. The changes in nutritional composition of rice plants infected by RBSDV and the ecological fitness of BPH feeding on the infected plants were studied under both artificial climate chamber and field conditions. Contents of 16 detected amino acids and soluble sugar in RBSDV infected rice plants were higher than those in the healthy ones. On the diseased plants BPH had significantly higher nymphal survival rates, nymphal duration of the males, weight of the female adults, as well as egg hatchability compared to BPH being fed on healthy plants. However, there was no obvious difference in female nymph duration, longevity and fecundity. Defense enzymes (superoxidase dismutase, SOD and catalase, CAT) and detoxifying enzymes (carboxylesterase, CAE and glutathione S-transferase, GST) in BPH adults fed on diseased plants had markedly higher activities. The results indicate rice plants infected by RBSDV improved the ecological fitness of the brown planthopper, a serious pest but not a transmitter of the RBSDV virus. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Osabc1k8, an abc1-like kinase gene, mediates abscisic acid sensitivity and dehydration tolerance response in rice seedlings

International Nuclear Information System (INIS)

Liu, Y.; Li, T.; Yang, C.

2015-01-01

The activity of bc1 complex kinase (ABC1K) protein family, which widely exists in prokaryotes and eukaryotes, consists of 15 members in rice, and the role of this family in plants has not yet been studied in details. In this study, a novel function of OsABC1K8 (LOC-Os06g48770), a member of rice ABC1K family, was characterized. The transcript level of OsABC1K8 changes in response to salt, dehydration, cold, PEG, oxidative (H/sub 2/O/sub 2/) stresses, or abscisic acid (ABA) treatment. Overexpression of OsABC1K8 significantly increased sensitivity to dehydration and reduced sensitivity to ABA. In the contrast, RNAi transgenic lines displayed significantly reduced sensitivity to dehydration stress and increased sensitivity to ABA. Furthermore, the transcriptional levels of several ABA/stress-regulated responsive genes were suppressed in OsABC1K8 over-expressing plants under dehydration stress. In conclusion, our results suggested that OsABC1K8 is a negative regulator in response to dehydration stress through an ABA-dependent pathway. (author)

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner

Science.gov (United States)

Domonkos, Ágota; Kovács, Szilárd; Gombár, Anikó; Kiss, Ernő; Horváth, Beatrix; Kováts, Gyöngyi Z.; Farkas, Attila; Tóth, Mónika T.; Ayaydin, Ferhan; Bóka, Károly; Fodor, Lili; Endre, Gabriella; Kaló, Péter

2017-01-01

Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2) and NAD1 (nodules with activated defense 1) genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules. PMID:29240711

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner

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Ágota Domonkos

2017-12-01

Full Text Available Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2 and NAD1 (nodules with activated defense 1 genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules.

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner.

Science.gov (United States)

Domonkos, Ágota; Kovács, Szilárd; Gombár, Anikó; Kiss, Ernő; Horváth, Beatrix; Kováts, Gyöngyi Z; Farkas, Attila; Tóth, Mónika T; Ayaydin, Ferhan; Bóka, Károly; Fodor, Lili; Ratet, Pascal; Kereszt, Attila; Endre, Gabriella; Kaló, Péter

2017-12-14

Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2) and NAD1 (nodules with activated defense 1) genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules.

UV-irradiation enhances rice allelopathic potential in rhizosphere soil

DEFF Research Database (Denmark)

Mahmood, Khalid; Khan, Muhammad Bismillah; Song, Yuan Yuan

2013-01-01

Ultraviolet-B radiation is rising continuously due to stratospheric ozone depletion over temperate latitudes. This study investigated effects of UV exposure on rice allelopathic potentials. For this purpose, two rice (Oryza sativa L.) cultivars BR-41 (high allelopathic = able to inhibit neighboring...... grass and lettuce). These bioassays showed significant inhibition in lettuce and barnyard growth after UV in both rice cultivars. Interestingly, Huajingxian, which did not exhibit allelopathic potential in absence of UV showed significant inhibition after UV exposure. Phenolics, enzymes activities...... and genes responsible for biosynthesis of allelopathic compounds were examined after UV exposure. Phenolic compounds accumulated in rice leaves were quantified through HPLC analysis. They were significantly higher in BR-41 leaves after UV exposure. Enzyme activities (PAL and C4H) were significantly higher...

Molecular Dynamics Simulation and Statistics Analysis Reveals the Defense Response Mechanism in Plants

Science.gov (United States)

Liu, Zhichao; Zhao, Yunjie; Zeng, Chen; Computational Biophysics Lab Team

As the main protein of the bacterial flagella, flagellin plays an important role in perception and defense response. The newly discovered locus, FLS2, is ubiquitously expressed. FLS2 encodes a putative receptor kinase and shares many homologies with some plant resistance genes and even with some components of immune system of mammals and insects. In Arabidopsis, FLS2 perception is achieved by the recognition of epitope flg22, which induces FLS2 heteromerization with BAK1 and finally the plant immunity. Here we use both analytical methods such as Direct Coupling Analysis (DCA) and Molecular Dynamics (MD) Simulations to get a better understanding of the defense mechanism of FLS2. This may facilitate a redesign of flg22 or de-novo design for desired specificity and potency to extend the immune properties of FLS2 to other important crops and vegetables.

PhosphoRice: a meta-predictor of rice-specific phosphorylation sites

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Que Shufu

2012-02-01

Full Text Available Abstract Background As a result of the growing body of protein phosphorylation sites data, the number of phosphoprotein databases is constantly increasing, and dozens of tools are available for predicting protein phosphorylation sites to achieve fast automatic results. However, none of the existing tools has been developed to predict protein phosphorylation sites in rice. Results In this paper, the phosphorylation site predictors, NetPhos 2.0, NetPhosK, Kinasephos, Scansite, Disphos and Predphosphos, were integrated to construct meta-predictors of rice-specific phosphorylation sites using several methods, including unweighted voting, unreduced weighted voting, reduced unweighted voting and weighted voting strategies. PhosphoRice, the meta-predictor produced by using weighted voting strategy with parameters selected by restricted grid search and conditional random search, performed the best at predicting phosphorylation sites in rice. Its Matthew's Correlation Coefficient (MCC and Accuracy (ACC reached to 0.474 and 73.8%, respectively. Compared to the best individual element predictor (Disphos_default, PhosphoRice archieved a significant increase in MCC of 0.071 (P Conclusions PhosphoRice is a powerful tool for predicting unidentified phosphorylation sites in rice. Compared to the existing methods, we found that our tool showed greater robustness in ACC and MCC. PhosphoRice is available to the public at http://bioinformatics.fafu.edu.cn/PhosphoRice.

Prone to fix: Resilience of the active nitrogen-fixing rice root microbiome

Science.gov (United States)

Hurek, Thomas; Sabale, Mugdha; Sarkar, Abhijit; Pees, Tobias; Reinhold-Hurek, Barbara

2016-04-01

Due to water consumption, many lowland rice areas in Asia are undergoing a transition that involves adoption of new management strategies, with crop rotations encompassing a non-flooded crop, including maize. Shifting from flooded to non-flooded cropping is likely to affect microbial nitrogen cycling. For analysis of the root-associated microbiome of rice and maize in response to flooding or nitrogen fertilizer, we combine methods of microbial ecology (Next-Generation sequencing of amplicons), and a reductionist approach with pure cultures of the endophytic diazotroph Azoarus sp.. Field plots of the ICON project (Introducing non-flooded crops in rice-dominated landscapes: Impact on Carbon, nitrogen and water budgets) at the International Rice Research Institute in the Philippines were analyzed. Root-associated activity of nitrogenase gene expression was assessed by quantitative RT-PCR of nifH. For rice, expression levels were surprisingly stable, in response to non-flooded versus flooded conditions, or in response to conventional nitrogen fertilizer applications versus lack of N-fertilizer. In contrast, the active diazotrophic population of maize roots was not resistant to N-fertilization, nifH expression strongly decreased. Concordant changes in the diazotrophic resident or active communities were detected by nifH amplicon sequence analysis, based on bacterial DNA or mRNA, respectively. For high-resolution analyses of the endobiome in gnotobiotic culture, we developed a dual fluorescence reporter system for Azoarcus sp. BH72 which allows to quantify and visualize epi- and endophytic gene expression by concfocal microscopy (CLSM). This allowed us to demonstrate sites of active nitrogen fixation (gene expression) in association with rice roots. We confirmed that at low nitrogen fertilizer levels, endophytic nifH gene expression persisted in rice roots, while it was repressed in maize roots. This supports our observation of remarkable stability of nitrogen fixation

Optimisation of wort production from rice malt using enzymes and ...

African Journals Online (AJOL)

Commercially, rice malt has never been successfully used in brewing because of its low free α-amino nitrogen (FAN) content. This study was designed to optimise rice malt replacement for barley malt in wort production and to improve FAN by adding α-amylase and protease. The response surface methodology (RSM) ...

Effect of Cold-Water Irrigation on Grain Quality Traits in japonica Rice Varieties from Yunnan Province, China

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Guo-zhen ZHAO

2009-09-01

Full Text Available The response of grain quality traits to cold-water irrigation and its correlation with cold tolerance were studied in 11 japonica rice varieties from Yunnan Province, China. The results indicated that the response of grain quality traits to the cold-water stress varied with rice varieties and grain quality traits. Under the cold-water stress, grain width, chalky rice rate, whiteness, 1000-grain weight, brown rice rate, taste meter value, peak viscosity, trough viscosity, breakdown viscosity and final viscosity significantly decreased, whereas grain length-width ratio, head rice rate, alkali digestion value, protein content and setback viscosity markedly increased. However, the other traits such as grain length, amylose content, milled rice rate, peak viscosity time and pasting temperature were not significantly affected by the cold-water stress. Significant correlations were discovered between phenotypic acceptability and cold response indices of taste meter value, protein content, peak viscosity and breakdown viscosity. Therefore, it would be very important to improve the cold tolerance of Yunnan rice varieties in order to stabilize and improve their eating quality.

Subacromial bursitis with giant rice bodies as initial presentation of rheumatoid arthritis.

Science.gov (United States)

Subramaniam, Ramesh; Tan, Justina Wei Lyn; Chau, Cora Yuk Ping; Lee, Keng Thiam

2012-10-01

Rice body formation is a nonspecific response to chronic synovial inflammation associated with tuberculous arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, seronegative inflammatory arthritis, and even osteoarthritis. Such bodies were termed rice bodies because of their close resemblance to grains of polished white rice. We present a case report of a middle-aged woman with right shoulder subacromial/subdeltoid bursitis with giant rice body formation as her initial presentation of rheumatoid arthritis. Her right shoulder symptoms resolved after subacromial and subdeltoid bursectomy and removal of the rice bodies. She subsequently developed inflammatory arthritis of other joints, met the criteria for rheumatoid arthritis, and has been treated medically.

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...

Nitrogen fixation in rice systems: State of knowledge and future prospects

International Nuclear Information System (INIS)

Ladha, J.K.; Reddy, P.M.

2001-01-01

Rice is the most important cereal crop. In the next three decades, the world will need to produce about 60% more rice than today's global production to feed the extra billion people. Nitrogen is the major nutrient limiting rice production. Development of fertilizer-responsive varieties in the Green Revolution, coupled with the realization by farmers of the importance of nitrogen, has led to high rates of N fertilizer use on rice. Increased future demand for rice will entail increased application of fertilizer N. Awareness is growing, however, that such an increase in agricultural production needs to be achieved without endangering the environment. To achieve food security through sustainable agriculture, the requirement for fixed nitrogen must increasingly met by biological nitrogen fixation (BNF) rather than by using nitrogen fixed industrially. It is thus imperative to improve existing BNF systems and develop N 2 -fixing non-leguminous crops such as rice. Here we review the potentials and constraints of conventional BNF systems in rice agriculture, as well as the prospects of achieving in planta nitrogen fixation in rice. (author)

SALT-RESPONSIVE ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice.

Science.gov (United States)

Schmidt, Romy; Schippers, Jos H M; Mieulet, Delphine; Watanabe, Mutsumi; Hoefgen, Rainer; Guiderdoni, Emmanuel; Mueller-Roeber, Bernd

2014-02-01

Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF.

MicroRNA-Mediated Gene Silencing in Plant Defense and Viral Counter-Defense

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Sheng-Rui Liu

2017-09-01

Full Text Available MicroRNAs (miRNAs are non-coding RNAs of approximately 20–24 nucleotides in length that serve as central regulators of eukaryotic gene expression by targeting mRNAs for cleavage or translational repression. In plants, miRNAs are associated with numerous regulatory pathways in growth and development processes, and defensive responses in plant–pathogen interactions. Recently, significant progress has been made in understanding miRNA-mediated gene silencing and how viruses counter this defense mechanism. Here, we summarize the current knowledge and recent advances in understanding the roles of miRNAs involved in the plant defense against viruses and viral counter-defense. We also document the application of miRNAs in plant antiviral defense. This review discusses the current understanding of the mechanisms of miRNA-mediated gene silencing and provides insights on the never-ending arms race between plants and viruses.

[Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

Science.gov (United States)

Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

2012-01-01

Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).

Constitutively active Arabidopsis MAP Kinase 3 triggers defense responses involving salicylic acid and SUMM2 resistance protein

KAUST Repository

Genot, Baptiste

2017-04-12

Mitogen-activated protein kinases (MAPKs) are important regulators of plant immunity. Most of the knowledge about the function of these pathways is derived from loss-of-function approaches. Using a gain-of-function approach, we investigated the responses controlled by a constitutively active (CA) MPK3 in Arabidopsis thaliana. CA-MPK3 plants are dwarfed and display a massive de-repression of defense genes associated with spontaneous cell death as well as accumulation of reactive oxygen species (ROS), phytoalexins and the stress-related hormones ethylene and salicylic acid (SA). Remarkably CA-MPK3/sid2 and CA-MPK3/ein2-50 lines which are impaired in SA synthesis and ethylene signaling, respectively, retain most of the CA-MPK3-associated phenotypes, indicating that constitutive activity of MPK3 can bypass SA and ethylene signaling to activate defense responses. A comparative analysis of the molecular phenotypes of CA-MPK3 and mpk4 autoimmunity suggested convergence between the MPK3 and MPK4-guarding modules. In support of this model, CA-MPK3 crosses with summ1 and summ2, two known suppressors of mpk4, resulted in a partial reversion of the CA-MPK3 phenotypes. Overall, our data unravel a novel mechanism by which the MAPK signaling network contributes to a robust defense response system.

A climatological analysis on the recent declining trend of rice quality in Japan

International Nuclear Information System (INIS)

Okada, M.; Iizumi, T.; Hayashi, Y.; Yokozawa, M.

2009-01-01

A remarkable declining trend in rice quality has already been observed in western Japan and the future global warming associated with climate change is likely to exacerbate such risk. In this study, a simple statistical model was constructed to estimate the rice quality, which is defined as the proportion of white immature grains on a prefectural scale, in terms of two major climate variables during the grain-filling stage: the cumulative weighted effective temperature delta and the cumulative solar radiation SR. In order to account for the uncertainties included in the processes involved, Bayesian inference was used to estimate the model parameters. The modeled time changes in rice quality correlated well to those observed. Specifically, the reproducibility of rice quality since 2000 was particularly high. These results suggested that a combination of the two climate factors was responsible for the recent variability in rice quality on a prefectural scale. Subsequently, the elasticity of rice quality relative to delta and SR was examined based on the model. The elasticity represents the relative change in rice quality in response to a change in delta or SR, with a positive (negative) sign indicating increased (decreased) quality. Consequently, the mean elasticity of the rice quality relative to SR was larger than that to delta in Kyushu. Moreover, the time changes of rice quality in Kyushu synchronized with that of SR under high temperature conditions, suggesting that rice plants become more sensitive to conditions of insufficient radiation if exposed to high temperatures. Consequently, it was concluded that the contribution of the radiation condition to the variation in rice quality become relatively larger along with the recent increase in temperature

Radioactive probes as diagnostic tools for rice tungro viruses

International Nuclear Information System (INIS)

Azzam, O.; Arboleda, M.; Reyes. J. de los

1996-01-01

Rice tungro bacilliform (RTBV) and rice tungro spherical viruses (RTSV) are the two viral components responsible for rice tungro disease which has seriously affected the irrigated rice ecosystem in Southeast Asia for the last 30 years. RTBV has an 8 Kb double-stranded DNA circular genome, and it is primarily responsible for induction of symptoms in infected plants. RTSV has a 12 kb single-stranded RNA genome. It does not induce any apparent symptoms in the infected plant, and it is transmitted by greenleafhopper. RTBV depends upon RTSV for its own transmission. The two viruses are limited to the vascular tissue of the rice plant and are present at a low titer. Most of the detection methods used for the identification of these viruses have relied on the virus protein properties and therefore, early detection of the virus activity was not possible. We were interested in evaluating tissue printing, dot blot, and southern techniques for early detection of virus nucleic acids in rice plant using radioactive and non radioactive probes. 32 P-labeled T7 or SP6 RNA polymerase transcripts complementary to the RTBV genome and RTSV coat protein genes were used as probes of the positive stand of both viruses. For nonradioactive probes, RTBV DNA genome was labeled using the ECL detection kit (Amersham). Preliminary results show that viral nucleic acids of RTBV and RTSV could be detected using both labelling systems. Non radioactive probes were comparable in their sensitivity to the radioactive probes. Less than 100 pg of viral DNA was detected in the dot-blot assays. More data will be presented to compare the efficiency and reliability of these two techniques in detecting early virus activity in the rice plant. (author)

Mineralization of nitrogen from nitrogen-15 labeled crop residues and utilization by rice

International Nuclear Information System (INIS)

Norman, R.J.; Gilmour, J.T.; Wells, B.R.

1990-01-01

The availability of N from the residues of the previous crop to the subsequent rice (Oryza sativa L.) crop is largely unknown. The objectives of this study were to (1) measure the mineralization of N from 15 N-labeled rice, soybean (Glycine max L.), and wheat (Triticum aestivum L.) residues and the uptake by a subsequent rice crop; and (2) compare the 15 N tracer method with the standard fertilizer-N response method used in field studies to quantify the N contribution from the crop residue to the next crop. Nitrogen mineralization from decomposing crop residues was measured by soil sampling prior to seeding the rice crop and after seeding by plant sampling the rice at maturity. The minimum estimate of the amount of residue N mineralized from the time of residue incorporation until rice harvest was 9, 52, and 38% of the rice, soybean, and wheat residue N, respectively. The amount of residue N recovered in the rice crop was 3, 11, and 37% of the rice, soybean, and wheat residue N, respectively. The lower the C/N ratio and the higher the amount of N in the residue, the lower was the amount of residue N recovered in the soil organic fraction at harvest and the higher was the amount of residue N mineralized. The 15 N tracer method compared favorably with the fertilizer N response method when the uptake efficiency of the fertilizer N was taken into account

Influence of Waterlogging on Carbohydrate Metabolism in Ragi and Rice Roots

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Kulkarni, S. S.

2013-04-01

Full Text Available Effect of different durations of waterlogging (4, 8 and 12 days stress on carbohydrate status and activities of some related enzymes in ragi and rice roots was studied. In both ragi and rice roots there was decrease in starch and total sugar content in response to waterlogging conditions. Activity of α amylase was decrease in ragi roots while opposite trend was noticed in case of rice roots. The activity of pyruvate kinase was markedly increased due to 4, 8 and 12 days waterlogging in ragi roots while such increase was noticed in rice roots due to 12 days stress. Treatment of waterlogging caused enhancement in the activity of alkaline inorganic pyrophosphatase in the roots of both ragi and rice.

The New Transgenic cry1Ab/vip3H Rice Poses No Unexpected Ecological Risks to Arthropod Communities in Rice Agroecosystems.

Science.gov (United States)

Lu, Zengbin; Dang, Cong; Han, Naishun; Shen, Zhicheng; Peng, Yufa; Stanley, David; Ye, Gongyin

2016-04-01

The ecological risks to nontarget organisms should be rigorously assessed before Bt crops are released. Here, the impacts of a new Cry1Ab/Vip3H rice line on arthropod communities in rice agroecosystems were evaluated across 3 yr. Arthropods collected via vacuum were sorted into five guilds. The abundance and proportion of each guild as well as community-level parameters were determined in Cry1Ab/Vip3H and control rice fields. Changes in arthropod species assemblage over sampling dates were investigated by principal response curves (PRCs). Cry1Ab/Vip3H rice did not exert significant impacts on the seasonal density and proportion of each guild, except parasitoids. Detritivore seasonal density, but not its relative abundance, was significantly affected by Cry1Ab/Vip3H rice. Four community indices (species richness S, Shannon-Wiener index H', Simpson index D, and evenness index J') were similar between rice types. PRCs revealed a slight community difference between rice types in the past two tested years, with rice types accounting for 1.0-3.5% of the variance among arthropod communities. However, sampling dates explain 32.1-67.6% for these community differences. Of the 46 taxa with higher species weights, 26.1% of the taxa were significantly different, including seven taxa with higher abundance and five with lower density in Cry1Ab/Vip3H rice fields. These differences may be attributed to change in abundance of prey or hosts but not to direct effects of Bt proteins. We infer that this new Cry1Ab/Vip3H rice line poses no unintended ecological risks to the arthropod community. © 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.

Effects of Extraction Methods on Phytochemicals of Rice Bran Oils Produced from Colored Rice.

Science.gov (United States)

Mingyai, Sukanya; Srikaeo, Khongsak; Kettawan, Aikkarach; Singanusong, Riantong; Nakagawa, Kiyotaka; Kimura, Fumiko; Ito, Junya

2018-02-01

Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits. This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice). RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3. Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods. HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice. The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO 2 and SE methods, respectively. In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best.

8273 RESPONSE OF NERICA AND SATIVA RICE LINES TO ...

African Journals Online (AJOL)

has no significant advantage over the lower (P0/N0 or P0/N30, P13/N0, P13/N30) and moderate ... do not recommend direct transfer of the “existing technology” in Asia to Africa without taking into ... As for the marketing of this rice, traders ...

Nitrogen and azolla response on growth of rice plant of Mitra-I variety with SRI method

International Nuclear Information System (INIS)

Nurmayulis; Putra Utama; Dewi Firnia; Hasnan Yani; Ania Citraresmini

2011-01-01

The research was conducted in Cisadap, Bunter Village, District of Sukadana, Ciamis Regency, West Java Province from January to May 2011. This study was carried out to know the response of growth of rice plant which was fertilized by nitrogen fertilizer and Azolla michrophylla using the system of rice intensification. This research used five dozes of nitrogen fertilizer (0 %, 25 %, 50 %, 75 %, 100 %) from N 92 kg ha -1 as a recommended nitrogen fertilizer (urea 200 kg ha -1 ), and also 1,13 ton ha -1 Azolla michrophylla. The result obtained from this research showed that the application of N fertilizer at 50 % of the recommend dose (100 kg ha -1 ) with adding Azolla at a rate of 1.13 t ha -1 gave good result in the terms of plant height at 2-6 weeks after planting and number of tillers at 2-7 weeks after planting. Interaction of the 50 % N fertilizer from the recommended dose planting 1,13 t ha -1 give the highest dry weight of Azolla of plants at seven weeks after planting. (author)

Rice Transcriptome Analysis to Identify Possible Herbicide Quinclorac Detoxification Genes

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Wenying eXu

2015-09-01

Full Text Available Quinclorac is a highly selective auxin-type herbicide, and is widely used in the effective control of barnyard grass in paddy rice fields, improving the world’s rice yield. The herbicide mode of action of quinclorac has been proposed and hormone interactions affect quinclorac signaling. Because of widespread use, quinclorac may be transported outside rice fields with the drainage waters, leading to soil and water pollution and environmental health problems.In this study, we used 57K Affymetrix rice whole-genome array to identify quinclorac signaling response genes to study the molecular mechanisms of action and detoxification of quinclorac in rice plants. Overall, 637 probe sets were identified with differential expression levels under either 6 or 24 h of quinclorac treatment. Auxin-related genes such as GH3 and OsIAAs responded to quinclorac treatment. Gene Ontology analysis showed that genes of detoxification-related family genes were significantly enriched, including cytochrome P450, GST, UGT, and ABC and drug transporter genes. Moreover, real-time RT-PCR analysis showed that top candidate P450 families such as CYP81, CYP709C and CYP72A genes were universally induced by different herbicides. Some Arabidopsis genes for the same P450 family were up-regulated under quinclorac treatment.We conduct rice whole-genome GeneChip analysis and the first global identification of quinclorac response genes. This work may provide potential markers for detoxification of quinclorac and biomonitors of environmental chemical pollution.

A PR-4 gene identified from Malus domestica is involved in the defense responses against Botryosphaeria dothidea.

Science.gov (United States)

Bai, Suhua; Dong, Chaohua; Li, Baohua; Dai, Hongyi

2013-01-01

Pathogenesis-related protein-4 (PR-4) family is a group of proteins with a Barwin domain in C-terminus and generally thought to be involved in plant defense responses. However, their detailed roles are poorly understood in defense of apple plant against pathogenic infection. In the present study, a new PR-4 gene (designated as MdPR-4) was identified from Malus domestica, and its roles in defense responses of apple were investigated. The open reading frame of MdPR-4 gene is of 447 bp encoding a protein of 148 amino acids with a Barwin domain in C-terminus and a signal peptide of 26 amino acids in N-terminus. Sequence and structural analysis indicated that MdPR-4 protein belongs to class II of PR-4 family. The high-level expression of MdPR-4 was observed in flowers and leaves as revealed by quantitative real time PCR. The temporal expression analysis demonstrated that MdPR-4 expression could be up-regulated by Botryosphaeria dothidea infection and salicylic acid (SA) or methyl jasmonate (MeJA) treatment, but suppressed by diethyldithiocarbamic acid (DIECA). In vitro assays, recombinant MdPR-4 protein exhibited ribonuclease activity specific for single strand RNA and significant inhibition to hyphal growth of three apple pathogenic fungi B. dothidea, Valsa ceratosperma and Glomerella cingulata. Moreover, the inhibition was reduced by the presence of 5'-ADP. Taken all together, the results indicate that MdPR-4 protein is involved in the defense responses of apple against pathogenic attack by directly inhibiting hyphal growth, and the inhibition is correlated with its ribonuclease activity, where as MdPR-4 expression is regulated by both SA and JA signaling pathway. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Prospects of Understanding the Molecular Biology of Disease Resistance in Rice

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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.

Rice Rab11 is required for JA-mediated defense signaling

Energy Technology Data Exchange (ETDEWEB)

Hong, Min Ji [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of); Lee, Yun mi [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Son, Young Sim [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Im, Chak Han [Eco-Friendliness Research Department, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju 660-360 (Korea, Republic of); Yi, Young Byung [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Rim, Yeong Gil [Systems and Synthetic Agrobiotech Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Bahk, Jeong Dong, E-mail: jdbahk@gnu.ac.kr [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Heo, Jae Bok, E-mail: jbheo72@dau.ac.kr [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of)

2013-05-17

Highlights: •OsRab11 interacts with OsOPR8. •OsOPR8 is localized in the cytosol and peroxisome. •OsRab11 enhances the NADPH consumption by OsOPR8. •Transgenic Arabidopsis overexpressing OsRab11 represents a pathogen-resistant phenotype. -- Abstract: Rab proteins play an essential role in regulating vesicular transport in eukaryotic cells. Previously, we characterized OsRab11, which in concert with OsGAP1 and OsGDI3 regulates vesicular trafficking from the trans-Golgi network (TGN) to the plasma membrane or vacuole. To further elucidate the physiological function of OsRab11 in plants, we performed yeast two-hybrid screens using OsRab11 as bait. OsOPR8 was isolated and shown to interact with OsRab11. A co-immunoprecipitation assay confirmed this interaction. The green fluorescent protein-OsOPR8 fusion product was targeted to the cytoplasm and peroxisomes of protoplasts from Arabidopsis thaliana. OsOPR8 exhibited NADPH-dependent reduction activity when 2-cyclohexen-1-one (CyHE) and 12-oxo-phytodienoic acid (OPDA) were supplied as possible substrates. Interestingly, NADPH oxidation by OsOPR8 was increased when wild-type OsRab11 or the constitutively active form of OsRab11 (Q78L) were included in the reaction mix, but not when the dominant negative form of OsRab11 (S28N) was included. OsRab11 was expressed broadly in plants and both OsRab11 and OsOPR8 were induced by jasmonic acid (JA) and elicitor treatments. Overexpressed OsRab11 transgenic plants showed resistance to pathogens through induced expression of JA-responsive genes. In conclusion, OsRab11 may be required for JA-mediated defense signaling by activating the reducing activity of OsOPR8.

DETERMINATION OF SPATIAL INTEGRATION AND SUBSTITUTION OF FOREIGN RICE FOR LOCAL RICE IN GHANA

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Philip Kofi ADOM

2014-11-01

Full Text Available This study tested for spatial integration in the rice market and the substitution of imported rice for local rice in Ghana. It is established that the markets for domestic imported rice are well-integrated, but not complete. The imperfect spatial integration of domestic foreign rice markets implies that the market provides opportunities for arbitrage. Price leadership roles are found to be determined by the kind of sub-inter-regional-trade network defined. However, in all, the Accra market emerged as a dominant market leader in the domestic foreign rice market. There is evidence of significant regional substitution of foreign rice for local rice in the long run, but the result is mixed in the short run. The result that local rice is not a perfect substitute for imported rice implies that price disincentive measures such as increasing the import tariffs on foreign rice will only produce a mild effect on increasing the producer price faced by local rice farmers, but aggravate the burden on households’ budget.

[Effects of fish on field resource utilization and rice growth in rice-fish coculture].

Science.gov (United States)

Zhang, Jian; Hu, Liang Liang; Ren, Wei Zheng; Guo, Liang; Wu, Min Fang; Tang, Jian Jun; Chen, Xin

2017-01-01

Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.

How Human Amygdala and Bed Nucleus of the Stria Terminalis May Drive Distinct Defensive Responses.

Science.gov (United States)

Klumpers, Floris; Kroes, Marijn C W; Baas, Johanna M P; Fernández, Guillén

2017-10-04

The ability to adaptively regulate responses to the proximity of potential danger is critical to survival and imbalance in this system may contribute to psychopathology. The bed nucleus of the stria terminalis (BNST) is implicated in defensive responding during uncertain threat anticipation whereas the amygdala may drive responding upon more acute danger. This functional dissociation between the BNST and amygdala is however controversial, and human evidence scarce. Here we used data from two independent functional magnetic resonance imaging studies [ n = 108 males and n = 70 (45 females)] to probe how coordination between the BNST and amygdala may regulate responses during shock anticipation and actual shock confrontation. In a subset of participants from Sample 2 ( n = 48) we demonstrate that anticipation and confrontation evoke bradycardic and tachycardic responses, respectively. Further, we show that in each sample when going from shock anticipation to the moment of shock confrontation neural activity shifted from a region anatomically consistent with the BNST toward the amygdala. Comparisons of functional connectivity during threat processing showed overlapping yet also consistently divergent functional connectivity profiles for the BNST and amygdala. Finally, childhood maltreatment levels predicted amygdala, but not BNST, hyperactivity during shock anticipation. Our results support an evolutionary conserved, defensive distance-dependent dynamic balance between BNST and amygdala activity. Shifts in this balance may enable shifts in defensive reactions via the demonstrated differential functional connectivity. Our results indicate that early life stress may tip the neural balance toward acute threat responding and via that route predispose for affective disorder. SIGNIFICANCE STATEMENT Previously proposed differential contributions of the BNST and amygdala to fear and anxiety have been recently debated. Despite the significance of understanding their

MAOHUZI6/ETHYLENE INSENSITIVE3-LIKE1 and ETHYLENE INSENSITIVE3-LIKE2 Regulate Ethylene Response of Roots and Coleoptiles and Negatively Affect Salt Tolerance in Rice1[OPEN

Science.gov (United States)

Yang, Chao; Ma, Biao; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Yin, Cui-Cui; Chen, Hui; Lu, Xiang; Chen, Shou-Yi; Zhang, Jin-Song

2015-01-01

Ethylene plays important roles in plant growth, development, and stress responses. The ethylene signaling pathway has been studied extensively, mainly in Arabidopsis (Arabidopsis thaliana). However, the molecular mechanism of ethylene signaling is largely unknown in rice (Oryza sativa). Previously, we have isolated a set of rice ethylene-response mutants. Here, we characterized the mutant maohuzi6 (mhz6). Through map-based cloning, we found that MHZ6 encodes ETHYLENE INSENSITIVE3-LIKE1 (OsEIL1), a rice homolog of ETHYLENE INSENSITIVE3 (EIN3), which is the master transcriptional regulator of ethylene signaling in Arabidopsis. Disruption of MHZ6/OsEIL1 caused ethylene insensitivity mainly in roots, whereas silencing of the closely related OsEIL2 led to ethylene insensitivity mainly in coleoptiles of etiolated seedlings. This organ-specific functional divergence is different from the functional features of EIN3 and EIL1, both of which mediate the incomplete ethylene responses of Arabidopsis etiolated seedlings. In Arabidopsis, EIN3 and EIL1 play positive roles in plant salt tolerance. In rice, however, lack of MHZ6/OsEIL1 or OsEIL2 functions improves salt tolerance, whereas the overexpressing lines exhibit salt hypersensitivity at the seedling stage, indicating that MHZ6/OsEIL1 and OsEIL2 negatively regulate salt tolerance in rice. Furthermore, this negative regulation by MHZ6/OsEIL1 and OsEIL2 in salt tolerance is likely attributable in part to the direct regulation of HIGH-AFFINITY K+ TRANSPORTER2;1 expression and Na+ uptake in roots. Additionally, MHZ6/OsEIL1 overexpression promotes grain size and thousand-grain weight. Together, our study provides insights for the functional diversification of MHZ6/OsEIL1 and OsEIL2 in ethylene response and finds a novel mode of ethylene-regulated salt stress response that could be helpful for engineering salt-tolerant crops. PMID:25995326

Overexpression of stress-related genes in Cuscuta campestris in response to host defense reactions

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Hamed Rezaei

2017-07-01

Full Text Available Herb dodder ( Cuscuta spp. is one of the most important parasitic plants that can severely affect crop yields in the world. So far, interactions of this parasitic plant with hosts were not investigated adequately. Here, we conducted a differential expression analyzes and identified a number of genes that were differentially expressed in haustorium tissue compared with the stem of Cuscuta campestris growing on Alfalfa. We obtained 439 cDNA fragments from haustoria (parasite-host connection zone and stems (25 cm away from connections zones using the cDNA-AFLP (Amplified Fragment Length Polymorphism method with eight different primer combinations. Of 439 transcript-derived fragments (TDFs that were detected, 145 fragments were identified as differentially expressed genes. Five TDF sequences were similar to known functional genes involved in signal transduction, metabolism, respiration, and stress responses. Genes encoding DEAD-box ATP-dependent RNA helicase, potential heme-binding protein, lysine-specific demethylase 5A were selected for qRT-PCR. The qRT-PCR analyzes confirmed the results obtained using cDNA-AFLP. Our findings shed light on the elicitation of dodder defense responses in the connection zone to overcome plant defense reactions.

Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

OpenAIRE

Imam, Mustapha Umar; Musa, Siti Nor Asma; Azmi, Nur Hanisah; Ismail, Maznah

2012-01-01

Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations inst...

Comparative transcriptome analysis of rice seedlings induced by different doses of heavy ion radiation

Science.gov (United States)

Zhao, Qian; Sun, Yeqing; Wang, Wei

2016-07-01

Highly ionizing radiation (HZE) in space is considered as a main factor causing biological effects on plant seeds. To investigate the different effects on genome-wide gene expression of low-dose and high-dose ion radiation, we carried out ground-base carbon particle HZE experiments with different cumulative doses (0Gy, 0.2Gy, 2Gy) to rice seeds and then performed comparative transcriptome analysis of the rice seedlings. We identified a total of 2551 and 1464 differentially expressed genes (DEGs) in low-dose and high-dose radiation groups, respectively. Gene ontology analyses indicated that low-dose and high-dose ion radiation both led to multiple physiological and biochemical activities changes in rice. By Gene Ontology analyses, the results showed that only one process-oxidation reduction process was enriched in the biological process category after high-dose ion radiation, while more processes such as response to biotic stimulus, heme binding, tetrapyrrole binding, oxidoreductase activity, catalytic activity and oxidoreductase activity were significantly enriched after low-dose ion radiation. The results indicated that the rice plants only focused on the process of oxidation reduction to response to high-dose ion radiation, whereas it was a coordination of multiple biological processes to response to low-dose ion radiation. To elucidate the transcriptional regulation of radiation stress-responsive genes, we identified several DEGs-encoding TFs. AP2/EREBP, bHLH, C2H2, MYB and WRKY TF families were altered significantly in response to ion radiation. Mapman analysis speculated that the biological effects on rice seedlings caused by the radiation stress might share similar mechanisms with the biotic stress. Our findings highlight important alterations in the expression of radiation response genes, metabolic pathways, and TF-encoding genes in rice seedlings exposed to low-dose and high-dose ion radiation.

Soil type links microbial colonization of rice roots to methane emission

NARCIS (Netherlands)

Conrad, R.; Klose, M.; Noll, M.; Kemnitz, D.; Bodelier, P.L.E.

2008-01-01

Most of the methane (CH4) emission from rice fields is derived from plant photosynthates, which are converted to CH4. Rice cluster I (RC-1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC-1 methanogens seem to play a crucial role in

Gene expression and activity of antioxidant enzymes in rice plants, cv. BRS AG, under saline stress.

Science.gov (United States)

Rossatto, Tatiana; do Amaral, Marcelo Nogueira; Benitez, Letícia Carvalho; Vighi, Isabel Lopes; Braga, Eugenia Jacira Bolacel; de Magalhães Júnior, Ariano Martins; Maia, Mara Andrade Colares; da Silva Pinto, Luciano

2017-10-01

The rice cultivar ( Oryza sativa L.) BRS AG, developed by Embrapa Clima Temperado, is the first cultivar designed for purposes other than human consumption. It may be used in ethanol production and animal feed. Different abiotic stresses negatively affect plant growth. Soil salinity is responsible for a serious reduction in productivity. Therefore, the objective of this study was to evaluate the gene expression and the activity of antioxidant enzymes (SOD, CAT, APX and GR) and identify their functions in controlling ROS levels in rice plants, cultivar BRS AG, after a saline stress period. The plants were grown in vitro with two NaCl concentrations (0 and 136 mM), collected at 10, 15 and 20 days of cultivation. The results indicated that the activity of the enzymes evaluated promotes protection against oxidative stress. Although, there was an increase of reactive oxygen species, there was no increase in MDA levels. Regarding genes encoding isoforms of antioxidant enzymes, it was observed that OsSOD3 - CU/Zn , OsSOD2 - Cu/Zn , OsSOD - Cu/Zn , OsSOD4 - Cu/Zn , OsSODCc1 - Cu/Zn , OsSOD - Fe , OsAPX1 , OsCATB and OsGR2 were the most responsive. The increase in the transcription of all genes among evaluated isoforms, except for OsAPX6 , which remained stable, contributed to the increase or the maintenance of enzyme activity. Thus, it is possible to infer that the cv. BRS AG has defense mechanisms against salt stress.

Glycaemic indices of different varieties of rice grown in Sri Lanka.

Science.gov (United States)

Hettiarachchi, P; Jiffry, M T; Jansz, E R; Wickramasinghe, A R; Fernando, D J

2001-03-01

Varieties of red raw rice are widely believed to have a better nutritional quality. The physiological effects of consuming different varieties of rice may not be so. The glycaemic index has been developed as an indicator of the physiological effect of foods. It is the glycaemic response of a 50 g carbohydrate portion of food expressed as a percentage of that of a standard. The objective of this study was to determine the glycaemic indices of different varieties of rice grown in Sri Lanka. Digestible carbohydrate content of 11 varieties of rice flour and bread were determined. Fasting blood samples followed by half-hourly samples for two hours were drawn after giving portions of either cooked rice or bread containing 50 g carbohydrate each. Fibre mill in Gampaha district. Twenty-two fibre mill workers aged between 25 and 50 years. The area under the blood glucose curve (AUC) for varieties of rice for a subject was calculated. Average AUC of 3 values for bread were calculated. Glycaemic index of each variety of rice was determined from the above variables. Glycaemic indices of varieties of rice differ. The glycaemic indices of varieties of red raw rice varied between 56 and 73 and the variety Bg 350 had the lowest glycaemic index. There was no significant difference between mean glycaemic index of varieties of white raw and some varieties of red raw rice (p = 0.2). Parboiled varieties of red raw rice had a significantly lower glycaemic index than white raw rice (p = 0.04) and some of the red raw rice (p = 0.005). The glycaemic index cannot be predicted from the colour of the rice grain. Red parboiled varieties of rice and Bg 350 can be recommended for patients with diabetes.

MicroRNAs responding to southern rice black-streaked dwarf virus infection and their target genes associated with symptom development in rice.

Science.gov (United States)

Xu, Donglin; Mou, Guiping; Wang, Kang; Zhou, Guohui

2014-09-22

Southern rice black-streaked dwarf virus (SRBSDV) is a recently emerged rice virus that has spread across Asia. This devastating virus causes rice plants to produce a variety of symptoms during different growth stages. MicroRNAs (miRNAs) comprise a large group of 21-24-nt RNA molecules that are important regulators of plant development processes and stress responses. In this study, we used microarray profiling to investigate rice miRNAs responding to SRBSDV infection at 3, 9, 15, and 20 days post-inoculation (dpi). Expression levels of 56 miRNAs were altered in SRBSDV-infected rice plants, with these changes classified into eight different regulation patterns according to their temporal expression dynamics. Fourteen miRNAs belonging to six families (miR164, R396, R530, R1846, R1858, and R2097) were significantly regulated at 20 dpi. We used RT-qPCR to search for expression level correlations between members of these families and their putative targets at 3, 9, and 15 dpi. Some members of the miR164, R396, R530, and R1846 families were found to be positively or negatively correlated with their respective targets during 3-15 days after SRBSDV infection, whereas in more cases the rice miRNAs were not in correlation with their targets along the post-inoculation period, suggesting that some additional factors may be involved in rice miRNA-target interactions. The reported functions of rice genes targeted by the miR164, R396, R530, R1846, and R1858 families indicated that these genes are associated with symptom development. These results provide insights into miRNA-mediated SRBSDV-rice interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

Mutant-inducing effect of γ-ray irradiation for hybrid rice F1 derived from cross of black glutinous rice x wild rice

International Nuclear Information System (INIS)

Mao Dezhi; Tang Yilan

1998-01-01

The hybrid rice F 1 plant derived from the back crossing of glutinous rice x wild rice was irradiated with γ-ray. The result of investigation to the induced mutant showed that through the selection and backcross, a black glutinous rice strain with the short stem, cold tolerance and high yield was developed. The analysis of the ability of heredity variance showed that the selection was effective for the husk colour, black glutinous and black Indica rice, but ineffective for the white Indica rice and seed setting

Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.