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A serine/threonine-protein phosphatase PP2A catalytic subunit is essential for asexual development and plant infection in Magnaporthe oryzae - Online First - Springer

A serine/threonine-protein phosphatase PP2A catalytic subunit is essential for asexual development and plant infection in Magnaporthe oryzae - Online First - Springer | Rice Blast | Scoop.it

Protein phosphatase 2A is a subgroup of widely conserved serine/threonine phosphatases and plays diverse roles in transcription, translation, differentiation, cell cycle, and signal transduction in many organisms. Taken together, our results indicated that PP2Ac plays vital roles in asexual development and plant infection by regulating Rho GTPases in the rice blast fungus and perhaps other plant pathogenic fungi.

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Interfacing Whispering Gallery Mode Optical Microresonator Biosensors with the Plant Defense Elicitor Chitin

Interfacing Whispering Gallery Mode Optical Microresonator Biosensors with the Plant Defense Elicitor Chitin | Rice Blast | Scoop.it

Chitin oligosaccharides were conjugated to optical biosensors.

Optical biosensor sensitivity was maintained after conjugation.

The conjugated surfaces demonstrate activity toward chitin receptors.

The conjugated devices successfully detected lectin, a model chitin receptor

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Investigating the Role of the Exocyst Complex in Infection-related Development of the Rice Blast Fungus Magnaporthe Oryzae

Host colonization is mediated through the secretion of effector proteins in order to neutralize host immune responses. However, the mechanism of the effector delivery during biotrophic invasion is not well defined in M. oryzae. In this thesis, I define the role of the exocyst complex, an evolutionarily conserved octameric protein complex involved in vesicle docking to the plasma membrane (composed of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84), during infection-related development in M. oryzae. Like other filamentous fungi, M. oryzae, exocyst components localize to the vegetative hyphal tip distinct from the Spitzenkörper. However, at the initial stage of infection-related development all the exocyst components localise as a ring at the cortex of the appressorium and re-assembles around the appressorium pore in an actin-dependent manner in mature appressoria. I report that the septin network is required for the transition of exocyst ring from periphery to the appressorium pore. Deletion of Exo70 and Sec5 showed significant reduction in protein secretion and plant infection. I show that Sec6 is required for the exocyst assembly around the appressorium pore and effector secretion from the appressorium. I report that, during biotrophic invasion, effectors are secreted through a distinct pathway. Apoplastic effectors, Bas4 and Slp1 are secreted via a Golgi-dependent pathway while secretion of cytoplasmic effectors, Pwl2 and Bas1 meditates through a Golgi-independent pathway in which exocyst components Exo70 and Sec5 are involved.

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Expression analysis of innate immunity related genes in the true/field blast resistance gene-mediated defence response

Expression analysis of innate immunity related genes in the true/field blast resistance gene-mediated defence response | Rice Blast | Scoop.it

In this work, the expression profiles of innate rice immunity related genes were examined in the mediated resistance response of true/field resistance genes. Three sets of rice near-isogenic lines (NILs) were used: the resistant NILs carrying true resistance genes in the genetic background of the susceptible cultivar Nipponbare (NB), NB-Pib, NB-Pizt, NB-Pik and NB-Pita2; NILs bearing field resistance genes pi21 in the susceptible cultivar Aichiasahi (AA) AA-pi21, Kahei (KHR). The marker gene OsWRKY45 of salicylic acid (SA) signalling was upregulated in all tested cultivars. And, JAmyb (marker gene of jasmonic acid signalling) showed higher upregulation in the resistance lines with nucleotide-binding sites and leucine-rich repeat (NBS-LRR) R genes Pib, Pizt, Pik, Pita2 and Pikahei than in NB and KHS. SalT of abscisic acid (ABA) signalling may be involved in the R/Avr interaction, including Pizt, Pik, pi21 and Pikahei. However, SalT was shown to negatively regulate Pib/AvrPib interaction. OsPR1b and PBZ1 were differentially expressed and strongly activated at a later stage by 48 h post-inoculation. Interestingly, there was evidence that OsPR1b and PBZ1 played an important role in the pi21-mediated response. It was shown that OsRAR1 could be upregulated in the true resistance line NB-Pita2 and the field resistance line KHR, while OsSGT1 and OsHSP90 could be upregulated in all tested lines. The involvement of these genes illustrated the complexity of the downstream signalling pathways in the mediated resistance response of true/field resistance genes.

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Elucidation of molecular and biochemical determinants in a natural rice rhizospheric isolate to attenuate rice blast pathogen Magnaporthe oryzae

Elucidation of molecular and biochemical determinants in a natural rice rhizospheric isolate to attenuate rice blast pathogen Magnaporthe oryzae | Rice Blast | Scoop.it

One isolate in particular, Pseudomonas chlororaphis EA105, was striking in its antifungal activity, drastically reducing vegetative growth of M. oryzae and almost completely halting the formation of M. oryzae's appressoria, a structure which is required for penetration into the host. When rice plants were root-treated with EA105 prior toM. oryzae infection, there were fewer lesions and the size of lesions was reduced. Plant defense mechanisms are typically mediated through salicylic acid (SA), jasmonic acid (JA), and/or ethylene (ETH). In plants which were treated with EA105, there was induction of genes involved in JA and ETH signaling while the expression of genes involved in salicylic acid (SA) signaling were largely unaffected. In addition SA, JA, and ETH, another critical plant hormone, abscisic acid (ABA) was also investigated. Some phytopathogens, including M. oryzae, have evolved mechanisms to trigger increased ABA biosynthesis in plants as part of the virulence process. EA105 prevented M. oryzae from up-regulating NCED3, the key enzyme involved in ABA biosynthesis. Similarly, EA105 prevented M. oryzae from up-regulating a putative rice beta glucosidase that is likely involved in activating conjugated inactive forms of the hormone. ABA appears to function not only as a suppressor of plant defense, but also a promoter of pathogenesis in M. oryzae through the acceleration of spore germination and appressoria formation. Spores and mycelia of M. oryzae produced ABA, though at levels lower than in plants, further indicating that ABA also plays an important role in fungi. However, even with the addition of exogenous ABA, EA105 was able to counter the virulence-promoting effects of this compound. In summary, EA105 can directly antagonize fungal growth and pathogenesis as well as increase host resistance to blast, mediated through JA and ETH signaling, and through the suppression of ABA-related susceptibility. 

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pFPL vectors for high-throughput protein localization in fungi: detecting cytoplasmic accumulation of putative effector proteins.

pFPL vectors for high-throughput protein localization in fungi: detecting cytoplasmic accumulation of putative effector proteins. | Rice Blast | Scoop.it

As part of a large scale project whose goal was to identify candidate effector proteins in Magnaporthe oryzae, we developed a suite of vectors that facilitate high throughput protein localization experiments in fungi. These vectors utilize GatewayTM recombinational cloning to place a gene’s promoter and coding sequences upstream and in frame with the fluorescent proteins eCFP, eGFP, mRFP, eYFP, or a nucleus-targeted mCHERRY variant. The respective GatewayTM cassettes were incorporated into Agrobacterium-based plasmids to allow efficient fungal transformation using hygromycin or geneticin resistance selection. Use of pFPL vectors with two different selectable markers provided a convenient way to label fungal cells with different fluorescent proteins, which, in turn, yielded new insights into M. oryzae appressorium structure and function. We demonstrate the utility of the pFPL vectors for identifying candidate effector proteins and we highlight a number of important factors that must be taken into consideration when screening for putative effectors that are translocated across the host plasma membrane.

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Genome-wide analyses of DNA-binding proteins harboring AT-hook motifs and their functional roles in the rice blast pathogen, Magnaporthe oryzae

The AT-hook is a DNA-binding motif originally described in the high mobility group A of non-histone chromatin components. The AT-hook proteins bind to the minor groove of adenine–thymine (AT) rich regions of DNA and act as transcriptional cofactors coordinating nucleoproteins during transcriptional regulation. In this study, a genome-widein silico analysis of AT-hook proteins was performed on the ascomycete plant pathogenic fungus,Magnaporthe oryzae. Targeted deletion of MoATH10 significantly increased pigmentation and conidiation, indicating that MoATH10 is negatively involved in the regulation of pigmentation and conidiation in M. oryzae. Pathogenicity assays revealed that theΔMoath10 mutant was less virulent. The reduced disease development of the ΔMoath10 mutant was due to a partial defect in invasive growth inside plant cells, but not appressorium-mediated penetration. These results suggest that MoATH10 is important for growth, development, and virulence in M. oryzae.

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Molecular tools for functional genomics in filamentous fungi: Recent advances and new strategies

Molecular tools for functional genomics in filamentous fungi: Recent advances and new strategies | Rice Blast | Scoop.it

In this review, various molecular tools used in filamentous fungi are compared and discussed, including methods for genetic transformation (e.g., protoplast transformation, electroporation, and microinjection), the construction of random mutant libraries (e.g., restriction enzyme mediated integration, transposon arrayed gene knockout, and Agrobacterium tumefaciens mediated transformation), and the analysis of gene function (e.g., RNA interference and transcription activator-like effector nucleases). We also focused on practical strategies that could enhance the efficiency of genetic manipulation in filamentous fungi, such as choosing a proper screening system and marker genes, assembling target-cassettes or vectors effectively, and transforming into strains that are deficient in the nonhomologous end joining pathway.

 

 


Via dromius, Steve Marek
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Facile preparation of silver nanoparticles immobilized on chitin nanofiber surfaces to endow antifungal activities

Facile preparation of silver nanoparticles immobilized on chitin nanofiber surfaces to endow antifungal activities | Rice Blast | Scoop.it

Silver nanoparticles were prepared on chitin nanofiber surfaces by UV light reduction of silver ions. The chitin nanofibers could be efficient substrates to immobilize silver nanoparticles with stable dispersion states. The dispersion and the nanocomposite film with acrylic resin showed characteristic absorption property in the visible light region due to the effect of the silver nanoparticles. Silver nanoparticles endowed strong antifungal activity to chitin nanofibers.


To assess the antifungal activity, spore germination of plant pathogenic fungi on the films was observed. Spores of all tested fungi germinated on the n-chitins at 24 h, and the n-chitins showed no antifungal activity. The nAgs/n-chitin composite films inhibited the spore germination of almost all tested pathogens at 24 h, and these antifungal activities were sustained at a high degree for 7 days. 

Elsa Ballini's insight:

Magnaporthe oryzae spore germination was observed after 24h on Chitin NF, or after 7 days on AgNPs/chitin NF

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Effects of pyramiding quantitative resistance genes pi21, Pi34, and Pi35 on rice leaf blast disease

Effects of pyramiding quantitative resistance genes pi21, Pi34, and Pi35 on rice leaf blast disease | Rice Blast | Scoop.it

Quantitative blast resistance genes may offer durable resistance because the selection pressure on M. oryzae to overcome resistance is low as a result of the genes’ moderate susceptibility. Because the effects of individual resistance genes are relatively small, pyramiding these genes in rice cultivars is a promising strategy. Here, we used near-isogenic and backcross lines of rice cultivar Koshihikari with single- or two-gene combinations of blast resistance genes (pi21, Pi34, and Pi35) to evaluate the suppression of leaf blast. The severity of the disease was assessed throughout the infection process. Resistance varied among the lines: Pi35 conferred the strongest resistance, while Pi34 showed the weakest effects. Two types of combined-gene interactions were observed, and they varied on the basis of gene combination and characteristic of the infection: (i) the combination of two resistance genes was more effective than either of the genes individually or (ii) the combination of two resistance genes was similar to the level of the most effective resistance gene in the pair. The most effective gene combination for the suppression of leaf blast was pi21 + Pi35.

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Fungal hemicellulose-degrading enzymes cause physical property changes concomitant with solubilization of cell wall polysaccharides

Fungal hemicellulose-degrading enzymes cause physical property changes concomitant with solubilization of cell wall polysaccharides | Rice Blast | Scoop.it

Main conclusion

Physical properties of wheat coleoptile segments decreased after treatment with hemicellulose-degrading enzymes, indicating that hemicellulosic polysaccharides function to control the strength of primary cell walls.

Abstract

Changes in the physical properties of plant cell walls, a viscoelastic structure, are thought to be one of the growth-limiting factors for plants and one of the infection-affecting factors for fungi. To study the significance of hemicellulosic polysaccharides that form cross-bridges between cellulose microfibrils in controlling cell wall strength in monocot plants, the effects of hemicellulose degradation by recombinant Magnaporthe oryzae xylanase and 1,3-1,4-β-glucanase, and recombinant Aspergillus oryzae xyloglucanase on the physical properties and polysaccharide solubilization were investigated using wheat (Triticum aestivum L.) coleoptiles. Treatments with xylanase or 1,3-1,4-β-glucanase significantly decreased the viscosity and elasticity of wheat coleoptile segments. In addition, xyloglucanase treatment slightly decreased the viscoelasticity. Furthermore, 1,3-1,4-β-glucan polymer was solubilized during hydrolysis with xylanase and xyloglucanase, even though neither enzyme had hydrolytic activity towards 1,3-1,4-β-glucan. These results suggest that xylan and xyloglucan interact with 1,3-1,4-β-glucan and that the composites and hemicellulosic polysaccharides form inter-molecular bridges. Degradation of these bridges causes decreases in the physical properties, resulting in increased extensibility of the cell walls. These findings provide a testable model in which wheat coleoptile cell walls are loosened by the degradation of hemicellulosic polysaccharides and hemicellulose-degrading enzymes play a significant role in loosening the walls during fungal infection.


Via Christophe Jacquet, Francis Martin
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Triterpenoid Glycosides from Medicago sativa as Antifungal Agents Against Pyricularia oryzae

Triterpenoid Glycosides from Medicago sativa as Antifungal Agents Against Pyricularia oryzae | Rice Blast | Scoop.it

The antifungal properties of saponin mixtures from alfalfa (Medicago sativa L.) tops and roots, of the corresponding mixtures of prosapogenins from tops, of purified saponins and sapogenins against the causal agent of rice blast Pyricularia oryzae isolates are presented. In vitro experiments highlighted a range of activities, depending on the assayed metabolite. The antifungal effects of the most promising prosapogenin mixture from alfalfa tops was confirmed by means of in planta tests using three different Italian cultivars of rice (Oryza sativa L. ssp. japonica), known to possess high, medium and low blast resistance. The evidenced antifungal properties of the tested metabolites allowed some considerations on their structure-activity relationship.

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PRISM - The Philippine Rice Information System (2014)

PRISM - The Philippine Rice Information System (2014) | Rice Blast | Scoop.it

The Philippine Rice Information System (PRISM) is an operational system for monitoring rice. It supports decision making and activity planning for increased rice production in the Philippines, and has nationwide coverage to help improve food security. It also serves as a platform to develop consistent and regular assessments of rice crop production, crop health, and crop losses due to natural calamities such as floods, droughts, and outbreaks of pests and diseases.


Via Kamoun Lab @ TSL
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MoST1 encoding a hexose transporter-like protein is involved in both conidiation and mycelial melanization of Magnaporthe oryzae

MoST1 encoding a hexose transporter-like protein is involved in both conidiation and mycelial melanization of Magnaporthe oryzae | Rice Blast | Scoop.it

In a large-scale gene disruption screen of Magnaporthe oryzae, a gene MoST1 encoding a protein belonging to the hexose transporter family was identified as a gene required for conidiation and culture pigmentation. 

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The receptor kinase CERK1 has dual functions in symbiosis and immunity signalling

The receptor kinase CERK1 has dual functions in symbiosis and immunity signalling | Rice Blast | Scoop.it
The establishment of symbiotic interactions between mycorrhizal fungi, rhizobial bacteria and their legume hosts involves a common symbiosis signalling pathway. This signalling pathway is activated by Nod factors produced by rhizobia and these are recognised by the Nod factor receptors NFR1/LYK3 and NFR5/NFP. Mycorrhizal fungi produce lipochitooligosaccharides (LCOs) similar to Nod factors, as well as short-chain chitin oligomers (CO4/5), implying commonalities in signalling during mycorrhizal and rhizobial associations. Here we show that NFR1/LYK3, but not NFR5/NFP, is required for the establishment of the mycorrhizal interaction in legumes. NFR1/LYK3 is necessary for the recognition of mycorrhizal fungi and the activation of the symbiosis signalling pathway leading to induction of calcium oscillations and gene expression. Chitin oligosaccharides also act as microbe associated molecular patterns that promote plant immunity via similar LysM receptor-like kinases. CERK1 in rice has the highest homology to NFR1 and we show that this gene is also necessary for the establishment of the mycorrhizal interaction as well as for resistance to the rice blast fungus. Our results demonstrate that NFR1/LYK3/OsCERK1 represents a common receptor for chitooligosaccharide-based signals produced by mycorrhizal fungi, rhizobial bacteria (in legumes) and fungal pathogens. It would appear that mycorrhizal recognition has been conserved in multiple receptors across plant species, but additional diversification in certain plant species has defined other signals that this class of receptors can perceive.

Via Christophe Jacquet
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Identification of a novel major locus for gray leaf spot resistance in Italian ryegrass ( Lolium multiflorum Lam.)

Identification of a novel major locus for gray leaf spot resistance in Italian ryegrass ( Lolium multiflorum Lam.) | Rice Blast | Scoop.it
Gray leaf spot (GLS), caused by Magnaporthe oryzae (anamorph Pyricularia oryzae), in ryegrasses is a very serious problem. Heavily infected small seedlings die within a matter of days, and stands of the grasses are seriously damaged by the disease. Thus, the development of GLS-resistant cultivars has become a concern in ryegrass breeding.
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Genome-wide association study of blast resistance in indica rice

Genome-wide association study of blast resistance in indica rice | Rice Blast | Scoop.it

Totally, thirty associated loci were identified. The strongest signal (Chr11_6526998, P =1.17 × 10−17) was located within the gene Os11g0225100, one of the rice Pia-blast resistance gene. Another association signal (Chr11_30606558) was detected around the QTL Pif. Our study identified the gene Os11g0704100, a disease resistance protein containing nucleotide binding site-leucine rich repeat domain, as the main candidate gene of Pif. In order to explore the potential mechanism underlying the blast resistance, we further examined a locus in chromosome 12, which was associated with CH149 (P =7.53 × 10−15). The genes, Os12g0424700 and Os12g0427000, both described as kinase-like domain containing protein, were presumed to be required for the full function of this locus. Furthermore, we found some association on chromosome 3, in which it has not been reported any loci associated with rice blast resistance. In addition, we identified novel functional candidate genes, which might participate in the resistance regulation.

 

This work provides the basis of further study of the potential function of these candidate genes. A subset of true associations would be weakly associated with outcome in any given GWAS; therefore, large-scale replication is necessary to confirm our results. Future research will focus on validating the effects of these candidate genes and their functional variants using genetic transformation and transferred DNA insertion mutant screens, to verify that these genes engender resistance to blast disease in rice.

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Molecular progress on the mapping and cloning of functional genes for blast disease in rice (Oryza sativa L.): current status and future considerations.

Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes.


Read More: http://informahealthcare.com/doi/abs/10.3109/07388551.2014.961403

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Antimicrobial Activity of UV-Induced Phenylamides from Rice Leaves

Antimicrobial Activity of UV-Induced Phenylamides from  Rice Leaves | Rice Blast | Scoop.it
Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated ph
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RNA Silencing in Filamentous Fungi: From Basics to Applications

n the post-genomics era, RNAi has rapidly become a powerful reverse genetic tool for elucidating gene function in a wide range of eukaryotes including fungi. In this review, we focus on recent discoveries of RNAi-related biological phenomena in fungi and their underlying molecular mechanisms. In addition, recent advances in RNA-mediated gene silencing technologies and their potential use for functional genomics studies in fungi are discussed.

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A redox-sensitive cysteine residue regulates the kinase activities of OsMPK3 and OsMPK6 in vitro

A redox-sensitive cysteine residue regulates the kinase activities of OsMPK3 and OsMPK6 in vitro | Rice Blast | Scoop.it

Highlights•

The kinase activities of OsMPK3 and OsMPK6 are induced under oxidative stress in rice.

The fourth cysteine residues, Cys179 and Cys210, are specific sites for the regulation of the in vitro kinase activities of both MAPKs.

The fourth cysteine residues, Cys179 and Cys210, are also involved in the redox-control of the in vitro kinase activities of both MAPKs.

A proposed model to explain the in vivo redox-control mechanism of both MAPKs is discussed.

Abstract

Two subgroup A rice mitogen-activated protein kinases (MAPKs), OsMPK3 and OsMPK6, have been implicated in multiple stress responses. However, the redox-control of the kinase activity of these proteins remains unknown. Here, immunoprecipitated OsMPK3 and OsMPK6 were initially activated in 15 min, and this activation transiently increased in rice seedlings under H2O2 stress. Among the six conserved cysteine residues, only the fourth cysteine residues in the kinase domain VII, Cys179 and Cys210, were required for the in vitro kinase activities of OsMPK3 and OsMPK6, respectively. Moreover, the substitution of these specific cysteine residues with serine abrogated in vitro kinase responses to redox conditions. These results suggest a novel redox-control mechanism for the kinase activities of these MAPKs in vivo.


Via Christophe Jacquet
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Two new anti-fungal diterpenoids from the husks of Oryza sativa

Two new anti-fungal diterpenoids from the husks of Oryza sativa | Rice Blast | Scoop.it

A new pimarane diterpene 6β,19β-epoxy-3β-hydroxy-5α,9β-pimara-7,15-diene and a new abietane diterpene 3β,20β-epoxy-3α-hydroxy-5α-abieta-8,11,13-trien-7-one were isolated from the rice husks ofOryza sativa L. Their structures were elucidated on the basis of extensive spectroscopic analysis, including MS, 1D and 2D NMR techniques. Compounds were found to show inhibitory activity against spore germination of Magnaporthe grisea with IC50 values 0.213 and 0.232 mM, respectively.

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The rice (Oryza sativa L.) LESION MIMIC RESEMBLING, which encodes an AAA-type ATPase, is implicated in defense response

The rice (Oryza sativa L.) LESION MIMIC RESEMBLING, which encodes an AAA-type ATPase, is implicated in defense response | Rice Blast | Scoop.it

Here, we report the identification, characterization and cloning of a novel rice (Oryza sativa L.) lesion mimic resembling (lmr) gene. We identified a gene that encodes an ATPase associated with various cellular activities type (AAA-type) protein. The pathogenesis-related (PR)  genes PBZ1 and PR1 were induced in lmr, which also showed enhanced resistance to rice blast (Magnaporthe oryzae) and bacterial blight (Xanthomonas oryzae pv. oryzae), suggesting LMR is a negative regulator of cell death in rice. The identification of lmr and cloning of the correspondingLMR gene provide an additional resource for the study of PCD in plants.

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Enhancement of innate immune system in monocot rice by transferring the dicotyledonous elongation factor Tu receptor

Enhancement of innate immune system in monocot rice by transferring the dicotyledonous elongation factor Tu receptor | Rice Blast | Scoop.it

The elongation factor Tu (EF-Tu) receptor (EFR) in cruciferous plants specifically recognizes the N-terminal acetylated elf18 region of bacterial EF-Tu and thereby activates plant immunity. Here, the transgenic rice plants (Oryza sativa L. ssp. japonica cv. Zhonghua 17 (ZH17))and cell cultures with constitutive expression of AtEFR were developed to investigate whether AtEFR senses EF-Tu and thus enhances bacterial resistance in the monocot plants. Importantly, pretreatment with elf18 triggered strong resistance to X. oryzae pv. oryzae in the transgenic plants, which is largely dependent on the AtEFR expression level. These plants also exhibited enhanced resistance to rice bacterial brown stripe, but not to rice fungal blast. 

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Resolving the polyphyletic nature of Pyricularia (Pyriculariaceae)

Resolving the polyphyletic nature of Pyricularia (Pyriculariaceae) | Rice Blast | Scoop.it

To clarify the taxonomic relationships among species that are magnaporthe- or pyricularia-like in morphology, we analysed phylogenetic relationships among isolates representing a wide range of host plants by using partial DNA sequences of multiple genes such as LSU, ITS, RPB1, actin and calmodulin. Species ofPyricularia s. str. belong to a monophyletic clade that includes all P. oryzae/P. grisea isolates tested, defining the Pyriculariaceae, which is sister to the Ophioceraceae, representing two novel families. These clades are clearly distinct from species belonging to the Gaeumannomyces pro parte/ Magnaporthiopsis/ Nakataea generic complex that are monophyletic and define the Magnaporthaceae. A re-evaluation of generic and species concepts within Pyriculariaceae is presented, and novelties are proposed based on morphological and phylogenetic data.

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NATURE OUTLOOK - RICE

NATURE OUTLOOK - RICE | Rice Blast | Scoop.it

A simple grain with global impact, rice has helped to build empires and fed revolutions. Now, scientists are starting a rice revolution of their own to feed a hungry world. By decoding genetics, improving breeding and, perhaps, reshaping the plant's biology, researchers are working to take the world’s most vital crop into the future.

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