Rice Blast
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Scientific articles on rice blast and wheat blast 20 new articles each month !
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Unpaywall: Read paywalled research papers for free.

Unpaywall: Read paywalled research papers for free. | Rice Blast | Scoop.it
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Effectors of Filamentous Plant Pathogens: Commonalities amid Diversity

Fungi and oomycetes are filamentous microorganisms that include a diversity of highly developed pathogens of plants. These are sophisticated modulators of plant processes that secrete an arsenal of effector proteins to target multiple host cell compartments and enable parasitic infection. Genome sequencing revealed complex catalogues of effectors of filamentous pathogens, with some species harboring hundreds of effector genes. Although a large fraction of these effector genes encode secreted proteins with weak or no sequence similarity to known proteins, structural studies have revealed unexpected similarities amid the diversity. This article reviews progress in our understanding of effector structure and function in light of these new insights. We conclude that there is emerging evidence for multiple pathways of evolution of effectors of filamentous plant pathogens but that some families have probably expanded from a common ancestor by duplication and diversification. Conserved folds, such as the oomycete WY and the fungal MAX domains, are not predictive of the precise function of the effectors but serve as a chassis to support protein structural integrity while providing enough plasticity for the effectors to bind different host proteins and evolve unrelated activities inside host cells. Further effector evolution and diversification arise via short linear motifs, domain integration and duplications, and oligomerization.
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Development and Evaluation of Near‑isogenic Lines with Different Blast Resistance Alleles at Piz Locus in Japonica Rice from The Lower Region of Yangtze River, China

Development and Evaluation of Near‑isogenic Lines with Different Blast Resistance Alleles at Piz Locus in Japonica Rice from The Lower Region of Yangtze River, China | Rice Blast | Scoop.it
Rice blast, caused by Magnaporthe oryzae, threatens rice production in most of the rice growing areas in China, especially in regions that grow japonica in recent years. The use of R genes is the most effective and economical approach for blast control. In our study, a set of six NILs were developed by introgression of six resistance alleles of the Piz locus (Pi2, Pigm, Pi40, Pi9, Piz, and Pizt) into a blast susceptible, high yielding, high quality japonica variety 07GY31 via marker assisted backcross breeding. Artificial inoculation using 144 M. oryzae isolates collected from the lower region of the Yangtze River, China, revealed that most of the NILs, including NIL-Pi2, NIL-Pigm, NIL-Pi40, NIL-Pi9, and NIL-Pizt exhibited broad-spectrum resistance against rice blast at the seedling stage with resistance frequencies (RF) ranging from 93.06% to 98.61%. NIL-Piz was an exception, with an RF of 21.53% which was slightly higher than the recurrent parent 07GY31. NIL-Pi40 and NIL-Pigm had broad-spectrum resistance (RF 93.33% and 71.67%, respectively) at the heading stage following inoculation of 60 isolates of M. oryzae. Field trials with artificial inoculation at the seedling and heading stage showed NIL-Pigm and NIL-Pi40 were highly resistant in 4 locations under high disease pressure. NIL-Pizt showed effective resistance in three locations from Zhejiang and Jiangsu provinces. This study shows that O. sativa Japonica alleles of the Piz locus confers resistance to M. oryzae, and provides an effective method to enhance seedling and panicle blast resistance in rice plants in the lower region of the Yangtze River, China.
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Disruption of actin motor function due to MoMyo5 mutation impairs host penetration and pathogenicity in Magnaporthe oryzae

Disruption of actin motor function due to MoMyo5 mutation impairs host penetration and pathogenicity in Magnaporthe oryzae | Rice Blast | Scoop.it
Actin motor myosin proteins are driving forces behind active transport of vesicles, and more than 20 classes of myosin were found to contribute to a wide range of cellular processes, including endocytosis and exocytosis, autophagy, cytokinesis, and actin cytoskeleton. In Saccharomyces cerevisiae, class V myosin Myo2 (ScMyo2p) is important for the transport of distinct sets of cargo to regions of the cell along the cytoskeleton for polarized growth. To study whether myosins play a role in the infectious structure appressorium formation or function of the rice blast fungus Magnaporthe oryzae, we identified MoMyo5 as an ortholog of ScMyo2p and characterized its function. Targeted gene disruption revealed that MoMyo5 is required for intracellular transport and is essential for hyphal growth and asexual reproduction. Despite that the ΔMomyo5 mutant could form appressorium-like structures, the structures were unable to penetrate host cells and were therefore nonpathogenic. We further found that MoMyo5 moves dynamically from the cytoplasm to the hyphal tip where it interacts with MoSec4, a Rab GTPase involved in secretory transport, hyphal growth, and fungal pathogenicity. Our studies indicate that class V myosin and its translocation are tightly coupled with hyphal growth, asexual reproduction, appressorium function, and pathogenicity in the rice blast fungus. This article is protected by copyright. All rights reserved.

Via Philip Carella
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Wheat Blast: A New Fungal Inhabitant to Bangladesh Threatening World Wheat Production

Wheat Blast: A New Fungal Inhabitant to Bangladesh Threatening World Wheat Production | Rice Blast | Scoop.it
World wheat production is now under threat due to the wheat blast outbreak in Bangladesh in early March 2016. This is a new disease in this area, indicating the higher possibility of this pathogen spreading throughout the Asia, the world’s largest wheat producing area. Occurrence of this disease caused ~3.5% reduction of the total wheat fields in Bangladesh. Its economic effect on the Bangladesh wheat market was little because wheat contributes to 3% of total cereal consumption, among which ~70% have been imported from other countries. However, as a long-term perspective, much greater losses will occur once this disease spreads to other major wheat producing areas of Bangladesh, India, and Pakistan due to the existing favorable condition for the blast pathogen. The wheat blast pathogen belongs to the Magnaporthe oryzae species complex causing blast disease on multiple hosts in the Poaceae family. Phylogenetic analysis revealed that the Bangladesh outbreak strains and the Brazil outbreak strains were the same phylogenetic lineage, suggesting that they might be migrated from Brazil to Bangladesh during the seed import. To protect wheat production of Bangladesh and its neighbors, several measures including rigorous testing of seed health, use of chemicals, crop rotation, reinforcement of quarantine procedures, and increased field monitoring should be implemented. Development of blast resistant wheat varieties should be a long-term solution and combination of different methods with partial resistant lines may suppress this disease for some time.
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A new proteinaceous pathogen‐associated molecular pattern (PAMP) identified in Ascomycete fungi induces cell death in Solanaceae

A new proteinaceous pathogen‐associated molecular pattern (PAMP) identified in Ascomycete fungi induces cell death in Solanaceae | Rice Blast | Scoop.it
Pathogen-associated molecular patterns (PAMPs) are detected by plant pattern recognition receptors (PRRs), which gives rise to PAMP-triggered immunity (PTI). We characterized a novel fungal PAMP, Cell Death Inducing 1 (RcCDI1), identified in the Rhynchosporium commune transcriptome sampled at an early stage of barley (Hordeum vulgare) infection.
The ability of RcCDI1 and its homologues from different fungal species to induce cell death in Nicotiana benthamiana was tested following agroinfiltration or infiltration of recombinant proteins produced by Pichia pastoris. Virus-induced gene silencing (VIGS) and transient expression of Phytophthora infestans effectors PiAVR3a and PexRD2 were used to assess the involvement of known components of PTI in N. benthamiana responses to RcCDI1.
RcCDI1 was highly upregulated early during barley colonization with R. commune. RcCDI1 and its homologues from different fungal species, including Zymoseptoria tritici, Magnaporthe oryzae and Neurospora crassa, exhibited PAMP activity, inducing cell death in Solanaceae but not in other families of dicots or monocots. RcCDI1-triggered cell death was shown to require N. benthamiana Brassinosteroid insensitive 1-Associated Kinase 1 (NbBAK1), N. benthamiana suppressor of BIR1-1 (NbSOBIR1) and N. benthamiana SGT1 (NbSGT1), but was not suppressed by PiAVR3a or PexRD2.
We report the identification of a novel Ascomycete PAMP, RcCDI1, recognized by Solanaceae but not by monocots, which activates cell death through a pathway that is distinct from that triggered by the oomycete PAMP INF1.
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OsMYC2 mediates numerous defence-related transcriptional changes via jasmonic acid signalling in rice

OsMYC2 mediates numerous defence-related transcriptional changes via jasmonic acid signalling in rice | Rice Blast | Scoop.it
Genome-wide transcriptional changes in OsMYC2-knockdown plants were shown.


Majority of the jasmonic acid-induced defence genes were regulated by OsMYC2.


OsMYC2 plays a central role in the biosynthesis of defence compounds in rice.


We propose myriad roles of OsMYC2 in jasmonic acid signalling for defence responses.
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Genetic diversity of disease resistance genes in foxtail millet (Setaria italica L.)

Genetic diversity of disease resistance genes in foxtail millet (Setaria italica L.) | Rice Blast | Scoop.it
Foxtail millet (Setaria italica L.) is a potential biofuel plant species, which is also one of the most commonly cultivated millet species for food and fodder. In this study we aimed to conduct a genome-wide identification of Coiled-coil, Nucleotide-binding site, Leucine-rice repeat (CNL) disease resistance genes (R-genes) in foxtail millet and study their evolutionary relationships. We identified 242 CNL genes with domains for NBS-LRR receptor function, with the addition of a few genes that contained transmembrane or zinc finger domains. Of the identified CNL genes, more than half formed gene clusters within the foxtail millet genome, with the majority showing evidence of tandem duplications. Syntenic analysis displayed chromosomal similarities among foxtail millet, rice, and barley, identifying strong syntenic relationships between foxtail millet and rice. Approximately 30% of the foxtail millet CNL gene clusters were found on chromosome Si08, exhibiting strong synteny with chromosome Os11 of rice. Selection pressure analysis showed a prevalence of purifying selection among all phylogenetic clades. We also identified the foxtail millet homologs of several well-studied R-genes in other species. The results from this study will have implications in research on CNL gene signaling pathways and development of durable resistance in foxtail millet and other crop species in general.
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Daily chart: Asian countries are eating more wheat

Daily chart: Asian countries are eating more wheat | Rice Blast | Scoop.it
“SO CENTRAL is rice to life in Asia that in many countries, rather than asking “how are you?” people ask, “have you eaten rice yet?” Around 90% of the world’s rice is consumed in Asia—60% of it in China, India and Indonesia alone. In every large country except Pakistan, Asians eat more rice than the global average.”
Via CIMMYT, Int., Rey Thomas
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Calcium-triggered accumulation of defense-related transcripts enhances wheat resistance to leaf blast

Calcium (Ca) is an essential macronutrient for plant growth, but its role in plant disease resistance remains largely elusive. Here, we investigated whether Ca increases the abundance of defense-related transcripts and enhances wheat resistance to leaf blast, caused by Pyricularia oryzae. To address these issues, wheat plants were grown in nutrient solution containing three Ca concentrations (0.26, 2.6 and 5 mM) either non-inoculated or inoculated with P. oryzae. Ca content in the leaves increased from 1.3 to 4.1% and blast severity decreased from 36.8 to 8.2% as the Ca concentration in the nutrient solution increased from 0.26 to 5 mM. The expression level of salicylic (SA) and jasmonic acid (JA) pathways gene markers (pathogenesis-related 1 and allene oxide synthase, respectively) as well as chitinase, β-1,3-glucanase, phenylalanine ammonia lyase, peroxidase and polyphenol oxidase was higher in inoculated plants grown with 5 mM Ca than in those grown with 0.26 mM Ca. Collectively, results suggest that Ca, in addition to its well-known effect in cell wall strengthening and inhibition of fungal-secreted pectolytic enzymes, plays an active role in wheat resistance to leaf blast through upregulation of defense-related gene expression upon P. oryzae infection. Both of SA and JA pathways seems to make up a central node in such Ca-mediated resistance.
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Profiling the extended phenotype of plant pathogens

Profiling the extended phenotype of plant pathogens | Rice Blast | Scoop.it
One of the most fundamental questions in plant pathology is what determines whether a pathogen grows within a plant? This question is frequently studied in terms of the role of elicitors and pathogenicity factors in the triggering or overcoming of host defences. However, this focus fails to address the basic question of how the environment in host tissues acts to support or restrict pathogen growth. Efforts to understand this aspect of host–pathogen interactions are commonly confounded by several issues, including the complexity of the plant environment, the artificial nature of many experimental infection systems and the fact that the physiological properties of a pathogen growing in association with a plant can be very different from the properties of the pathogen in culture. It is also important to recognize that the phenotype and evolution of pathogen and host are inextricably linked through their interactions, such that the environment experienced by a pathogen within a host, and its phenotype within the host, is a product of both its interaction with its host and its evolutionary history, including its co-evolution with host plants. As the phenotypic properties of a pathogen within a host cannot be defined in isolation from the host, it may be appropriate to think of pathogens as having an ‘extended phenotype’ that is the product of their genotype, host interactions and population structure within the host environment. This article reflects on the challenge of defining and studying this extended phenotype, in relation to the questions posed below, and considers how knowledge of the phenotype of pathogens in the host environment could be used to improve disease control.

What determines whether a pathogen grows within a plant?

What aspects of pathogen biology should be considered in describing the extended phenotype of a pathogen within a host?

How can we study the extended phenotype in ways that provide insights into the phenotypic properties of pathogens during natural infections?

Via Christophe Jacquet, Freddy Monteiro, Tatsuya Nobori
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7th European Conference on Prokaryotic and Fungal Genomics

7th European Conference on Prokaryotic and Fungal Genomics | Rice Blast | Scoop.it

It is our great pleasure to cordially invite you to the 7th European Conference on Prokaryotic and Fungal Genomics – ProkaGENOMICS 2017. This meeting will take place from 19–22 September 2017 in Göttingen/Germany, and focus on the presentation of the latest results in the rapidly growing field of prokaryotic and fungal functional genomics. The ProkaGENOMICS conference series has been launched already in 2003 when the genomics revolution was still in its infancy. At present, the increasing power of high-throughput technologies drives research in microbiology. The OMICS-technologies have become the new mantra in functional microbial genomics, allowing the simultaneous examination of thousands of genes, transcripts, proteins, or metabolites. These powerful tools yielded completely new scientific objectives, e.g. monitoring microbial community dynamics as well as comprehensive cellular processes under a wide range of different conditions. ProkaGENOMICS 2017 will address this challenging field of microbiology. The main conference topics will be: • Towards Biotechnology – Metabolic Modeling & Genome/ Enzyme Engineering • Systems and Synthetic Biology • Omics at its best – Global Gene Regulation & Proteome Dynamics • MetaOmics & Microbial Ecosystems • Infectiongenomics & Host Microbe Interplay • Microbial Evolution, Population Genomics & Epidemiology • Microbiome Host Interaction • Functional Phage Genomics

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

SP-LL-37, human antimicrobial peptide, enhances disease resistance in transgenic rice | Rice Blast | Scoop.it
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.
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PHD position : Genetic and molecular interactions between NIS (Nitrogen-Induced Susceptibility) and the different components of NUE (Nitrogen Use Efficiency)

PHD position : Genetic and molecular interactions between NIS (Nitrogen-Induced Susceptibility) and the different components of NUE (Nitrogen Use Efficiency) | Rice Blast | Scoop.it

In Camargue, rice blast, caused by Magnaporthe oryzae, is an increasing constraint and provokes severe damage. The identification of resistant varieties is difficult in the field due to the randomness of epidemics. This difficulty has unfortunately led to the registration of very susceptible varieties in particularly if the agricultural practices are favorable for the disease, such as the use of high nitrogen fertilization to increase yield. This phenomenon, called Nitrogen-Induced Susceptibility (NIS), is partly correlated to the nitrogen use efficiency (NUE). This project aims to identify european rice varieties combining good blast resistance and reduced NIS, while having high NUE. A panel of 200 temperate rice varieties ‘ll be screened during this project. These varieties have been already genotyped and thus can be used to conduct genome wide association mapping. Secondly, the NIS, the NUE and their interaction will be characterized more precisely and metabolic and molecular markers of these two phenomena will be quantified. These results will be a support to the breeding program in Camargue.

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The Phytopathogen Evolution and Adaptation

The Phytopathogen Evolution and Adaptation | Rice Blast | Scoop.it
So often new phytopathogens emerge and appear primarily in acute form and then take a chronic form; such populations, however, in general have a limited appearance because of the lack of suitable environmental conditions. The emergence of new pathogens needs to be explored in the light of their evolutionary adaptation. This new volume focuses on the study of quantitative aspects of host-phytopathogen linkages that result in the emergence of aggressive phytopathogens. The book examines the evolution and adaptation of phytopathogens from several cropping systems.
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Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in Magnaporthe oryzae

Chitin deacetylation results in the formation of chitosan, a polymer of β1,4-linked glucosamine. Chitosan is known to have important functions in the cell walls of a number of fungal species, but its role during hyphal growth has not yet been investigated. In this study, we have characterized the role of chitin deacetylation during vegetative hyphal growth in the filamentous phytopathogen Magnaporthe oryzae. We found that chitosan localizes to the septa and lateral cell walls of vegetative hyphae, and identified two chitin deacetylases expressed during vegetative growth – CDA1 and CDA4. Deletion strains and fluorescent protein fusions demonstrated that CDA1 is necessary for chitin deacetylation in the septa and lateral cell walls of mature hyphae in colony interiors, whereas CDA4 deacetylates chitin in the hyphae at colony margins. However, although the ∆cda1 strain was more resistant to cell wall hydrolysis, growth and pathogenic development were otherwise unaffected in the deletion strains. The role of chitosan hydrolysis was also investigated. A single gene encoding a putative chitosanase (CSN) was discovered in M.oryzae and found to be expressed during vegetative growth. However, chitosan localization, vegetative growth and pathogenic development
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Assessment of the virulence spectrum and its association with genetic diversity in Magnaporthe oryzae populations from sub-Saharan Africa

Assessment of the virulence spectrum and its association with genetic diversity in Magnaporthe oryzae populations from sub-Saharan Africa | Rice Blast | Scoop.it
A collection of 122 isolates of Magnaporthe oryzae, from nine sub-Saharan African countries, was assessed for virulence diversity and genetic relatedness. The virulence spectrum was assessed by pathotype analysis with a panel of 43 rice genotypes consisting of differential lines carrying 24 blast resistance genes (R- genes), contemporary African rice cultivars, and susceptible checks. The virulence spectrum among isolates ranged from 5-80%. Five isolates were avirulent to the entire rice panel, while two isolates were virulent to ~75% of the panel. Overall, cultivar 75-1-127, the Pi9 R-gene donor, was resistant to all isolates (100%), followed by four African rice cultivars (AR105, NERICA 15, 96%; NERICA 4, 91%, and F6-36, 90%). Genetic relatedness of isolates was assessed by single nucleotide polymorphisms (SNP) derived from genotyping-by-sequencing (GBS) and by vegetative compatibility tests. Phylogenetic analysis of SNPs of a subset of isolates (n=78) revealed seven distinct clades which differed in virulence. Principal component analysis showed isolates from East Africa were genetically distinct from those from West Africa. Vegetative compatibility tests of a subset of isolates (n=65) showed no common groups among countries. This study shows that blast disease could be controlled by pyramiding of Pi9 together with other promising R-genes into rice cultivars which are adapted to East and West African regions.
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MoJMJ1, Encoding a Histone Demethylase Containing JmjC Domain, Is Required for Pathogenic Development of the Rice Blast Fungus, Magnaporthe oryzae

MoJMJ1, Encoding a Histone Demethylase Containing JmjC Domain, Is Required for Pathogenic Development of the Rice Blast Fungus, Magnaporthe oryzae | Rice Blast | Scoop.it
Histone methylation plays important roles in regulating chromatin dynamics and transcription in eukaryotes. Implication of histone modifications in fungal pathogenesis is, however, beginning to emerge. Here, we report identification and functional analysis of a putative JmjC-domain-containing histone demethylase in Magnaporthe oryzae. Through bioinformatics analysis, we identified seven genes, which encode putative histone demethylases containing JmjC domain. Deletion of one gene, MoJMJ1, belonging to JARID group, resulted in defects in vegetative growth, asexual reproduction, appressorium formation as well as invasive growth in the fungus. Western blot analysis showed that global H3K4me3 level increased in the deletion mutant, compared to wild-type strain, indicating histone demethylase activity of MoJMJ1. Introduction of MoJMJ1 gene into ΔMojmj1 restored defects in pre-penetration developments including appressorium formation, indicating the importance of histone demethylation through MoJMJ1 during infection-specific morphogenesis. However, defects in penetration and invasive growth were not complemented. We discuss such incomplete complementation in detail here. Our work on MoJMJ1 provides insights into H3K4me3-mediated regulation of infection-specific development in the plant pathogenic fungus.
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Standardization of pearl millet blast (Magnaporthe grisea) phenotyping under artificial conditions

Standardization of pearl millet blast (Magnaporthe grisea) phenotyping under artificial conditions | Rice Blast | Scoop.it
In India, pearl millet blast caused by Magnaporthe grisea is becoming a serious problem and causes significant yield losses in various parts of country. In this study, we have standardized phenotyping procedure against pearl millet blast disease. Further, we have evaluated 15 inbred lines in which three entries were highly resistant viz., PPMI 1087, PPMI 1089 and PPMI 660 and two entries (PPMI 1084 and J 108) were identified as resistant. This method will be useful for large scale screening of pearl millet entries against blast pathogen
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A web-based microsatellite database for the Magnaporthe oryzae genome

A web-based microsatellite database for the Magnaporthe oryzae genome | Rice Blast | Scoop.it
Rice blast disease caused by a fungal pathogen Magnaporthe oryzae, which results up to 90% crop yield loss during severe epidemics [1]. Rice fulfils food energy requirement of 2/3rd of world’s population. Understanding about the pathogen and its diversity among different strains of a particular geographic region can help breeders for proper deployments of blast resistance genes in the region. DNA markers are the unique regions within a genome which may be associated with the genes responsible for specific trait in an organism. Microsatellite or simple sequence repeat markers are stretches of DNA in which the same short nucleotide sequence is tandemly repeated within the genome [2]. These sequences are also known as simple sequence repeats (SSRs) or simple tandem repeats (STRs). SSR is generally a 1-6 nucleotide sequence variations present across the eukaryotic genome [3,4, 5]. Polymorphism, or variation, among SSR markers is determined by the number of times of the base sequence repeats. Its hyper-variability in among the related organisms makes them excellent markers for phenotype mapping, marker assisted selection, genotype identification and analysis of genetic diversity. The nature of SSRs gives them a number of advantages over other molecular markers by their abundances in genome, high-level of polymorphisms, codominance nature, open accessibility, simple assay method, and feasibility to use at high-throughput level. They are one of the most advanced marker technologies, after single nucleotide polymorphism (SNP) markers, available in genetic research. Considering these above benefits, a SSR marker database was developed from genomes of two M. oryzae isolates, RML-29 (avirulent, designated name Mo-nwi-55) and RP-2421 (virulent, designated name Mo-nwi-31). These two isolates were selected for the database development on the basis of their virulence spectrum towards different rice blast resistance genes.
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Anti-blast mutant screened from tissue cultured with crude toxin from Pyricularia oryzae.

The crude toxin was extracted from liquid of different Jiangsu province's physiological races of rice blast fungus, the local rice variety which was sensitive to rice blast was chosen as tested material. The effects of crude toxin on its seed germination, mature embryo callus's growth and differentiation were studied. Under appropriate concentrations of crude toxin, the blast-resistant mutant during the whole time of embryo callus's growth was screen out. The results showed that the seeds' germination was inhibited strongly with the increasing of the toxin concentration, and the germination was totally inhibited when the concentration was 1 mL/10 mL. The growth of embryo callus was inhibited gradually with the increasing of toxin's concentration, and the callus's growth was completely stopped when the concentration was 25%. The differentiation of embryo callus was sensitive to toxin, and the differentiation rate of seedling was dropped significantly when the concentration was 5%. The rice seedlings from the mature embryo cultured with crude toxin were injected by rice blast fungus in the field, their disease resistance was improved compared with CK. This study suggested that the method of using the media including toxin to induct mutant was a effective protocol to improve the rice resistance of rice-blast.
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Comparison and Validation of Putative Pathogenicity-Related Genes Identified by T-DNA Insertional Mutagenesis and Microarray Expression Profiling in Magnaporthe oryzae

Comparison and Validation of Putative Pathogenicity-Related Genes Identified by T-DNA Insertional Mutagenesis and Microarray Expression Profiling in Magnaporthe oryzae | Rice Blast | Scoop.it

High-throughput technologies of functional genomics such as T-DNA insertional mutagenesis and microarray expression profiling have been employed to identify genes related to pathogenicity in Magnaporthe oryzae. However, validation of the functions of individual genes identified by these high-throughput approaches is laborious. In this study, we compared two published lists of genes putatively related to pathogenicity in M. oryzae identified by T-DNA insertional mutagenesis (comprising 1024 genes) and microarray expression profiling (comprising 236 genes), respectively, and then validated the functions of some overlapped genes between the two lists by knocking them out using the method of target gene replacement. Surprisingly, only 13 genes were overlapped between the two lists, and none of the four genes selected from the overlapped genes exhibited visible phenotypic changes on vegetative growth, asexual reproduction, and infection ability in their knockout mutants. Our results suggest that both of the lists might contain large proportions of unrelated genes to pathogenicity and therefore comparing the two gene lists is hardly helpful for the identification of genes that are more likely to be involved in pathogenicity as we initially expected.

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Functional Characterization of Endophytic Fungal Community Associated with Oryza sativa L. and Zea mays L.

Functional Characterization of Endophytic Fungal Community Associated with Oryza sativa L. and Zea mays L. | Rice Blast | Scoop.it
In a natural ecosystem, the plant is in a symbiotic relationship with beneficial endophytes contributing huge impact on its host plant. Therefore, exploring beneficial endophytes and understanding its interaction is a prospective area of research. The present work aims to characterize the fungal endophytic communities associated with healthy maize and rice plants and to study the deterministic factors influencing plant growth and biocontrol properties against phytopathogens, viz, Pythium ultimum, Sclerotium oryzae, Rhizoctonia solani, and Pyricularia oryzae. A total of 123 endophytic fungi was isolated using the culture-dependent approach from different tissue parts of the plant. Most dominating fungal endophyte associated with both the crops belong to genus Fusarium, Sarocladium, Aspergillus, and Penicillium and their occurrence was not tissue specific. The isolates were screened for in vitro plant growth promotion, stress tolerance, disease suppressive mechanisms and based on the results, each culture from both the cereal crops was selected for further study. Acremonium sp. (ENF 31) and Penicillium simplicisssum (ENF22), isolated from maize and rice respectively could potentially inhibit the growth of all the tested pathogens with 46.47 ± 0.16 mm to 60.09 ± 0.04 mm range zone of inhibition for ENF31 and 35.48 ± 0.14 to 62.29 ± 0.15 mm for ENF22. Both significantly produce the defensive enzymes, ENF31 could tolerate a wide range of pH from 2 to 12, very important criteria, for studying plant growth in different soil types, especially acidic as it is widely prevalent here, making more land unsuitable for cultivation. ENF22 grows in pH range 3–12, with 10% salt tolerating ability, another factor of consideration. Study of root colonization during 7th to 30th days of growth phase reveals that ENF31 could colonize pleasantly in rice, though a maize origin, ranging from 1.02 to 1.21 log10 CFU/g root and in maize, it steadily colonizes ranging from 0.95 to 1.18 log10 CFU, while ENF22 could colonize from 0.98 to 1.24 Log10CFU/g root in rice and 1.01 to 1.24Log10CFU/g root in maize, just the reverse observed in Acremonium sp. Therefore, both the organism has the potency of a promising Bio-resource agent, that we must definitely explore to fill the gap in the agriculture industry.
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Transposon-mediated epigenetic regulation contributes to phenotypic diversity and environmental adaptation in rice

Transposon-mediated epigenetic regulation contributes to phenotypic diversity and environmental adaptation in rice | Rice Blast | Scoop.it

Most rice genes are associated with transposable elements (TEs).
TE-based epigenetic regulation of expression of adjacent genes is prevalent in rice.
Environmental conditions can activate TEs to generate genetic or epigenetic variations.
TE-driven variations contributed to rice evolution and northward expansion.

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Epidemiology, virulence and molecular diversity in blast [Magnaporthe grisea (Hebert) Barr.]

Epidemiology, virulence and molecular diversity in blast [Magnaporthe grisea (Hebert) Barr.] of pearl millet [Pennisetum glaucum (L.) R. Br.] and resistanc
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