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Identification of rice blast resistance genes using international monogenic differentials

Identification of rice blast resistance genes using international monogenic differentials | Rice Blast | Scoop.it

In the following study, 44 representative local blast isolates were inoculated onto international monogenic differentials carrying 24 major blast resistance genes. These results suggest that Pi9, Pi19, Piz, Piz-5, Piz-t, Pi12(t), Pi5(t) and Pik-h may be important R genes for preventing blast disease. Based on these data, a useful strategy for managing rice blast disease by stacking pyramiding blast R genes against pathogenic M. oryzae isolates in the Jilin Province was proposed.

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Rice Blast
Scientific articles on rice blast and wheat blast 20 new articles each month !
Curated by Elsa Ballini
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Identification of Sternbin and Naringenin as Detoxified Metabolites from the Rice Flavanone Phytoalexin Sakuranetin by Pyricularia oryzae

Sakuranetin (1) is a flavanone phytoalexin that has been reported to play an important role in disease resistance in rice plants. The rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) has been reported to metabolize 1 to lower its antifungal activity. Here, two flavanones, sternbin (2) and naringenin (3), were identified as metabolites of 1 in P. oryzae suspension culture by liquid chromatography tandem mass spectrometry (LC/MS/MS). The inhibition of 1, 2, and 3 on P. oryzae mycelial growth were 45%, 19%, and 19%, respectively, at a concentration of 100 μM. Thus, 2 and 3 are detoxified metabolites of 1 by P. oryzae.
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Regulatory cross-talks and cascades in rice hormone biosynthesis pathways contribute to stress signaling

Regulatory cross-talks and cascades in rice hormone biosynthesis pathways contribute to stress signaling | Rice Blast | Scoop.it
Crosstalk among different hormone signaling pathways play an important role in modulating plant response to both biotic and abiotic stress. Hormone activity is controlled by its bio-availability, which is again influenced by its biosynthesis. Thus independent hormone biosynthesis pathways must be regulated and co-ordinated to mount an integrated response. One of the possibilities is to use cis-regulatory elements to orchestrate expression of hormone biosynthesis genes. Analysis of CREs, associated with differentially expressed hormone biosynthesis related genes in rice leaf under Magnaporthe oryzae attack and drought stress enabled us to obtain insights about cross-talk among hormone biosynthesis pathways at the transcriptional level. We identified some master transcription regulators that co-ordinate different hormone biosynthesis pathways under stress. We found that Abscisic acid and Brassinosteroid regulate Cytokinin conjugation; conversely Brassinosteroid biosynthesis is affected by both Abscisic acid and Cytokinin. Jasmonic acid and Ethylene biosynthesis may be modulated by Abscisic acid through DREB transcription factors. Jasmonic acid or Salicylic acid biosynthesis pathways are co-regulated but they are unlikely to influence each other’s production directly. Thus multiple hormones may modulate hormone biosynthesis pathways through a complex regulatory network, where biosynthesis of one hormone is affected by several other contributing hormones.
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The germin-like protein OsGLP2-1 enhances resistance to fungal blast and bacterial blight in rice

The germin-like protein OsGLP2-1 enhances resistance to fungal blast and bacterial blight in rice | Rice Blast | Scoop.it
Rice (Oryza sativa) blast caused by Magnaporthe oryzae and bacterial blight caused by Xanthomonas oryzae pv. oryzae are the two most destructive rice diseases worldwide. Germin-like protein (GLP) gene family is one of the important defense gene families which have been reported to be involved in disease resistance in plants. Although GLP proteins have been demonstrated to positively regulate leaf blast resistance in rice, their involvement in resistance to panicle blast and bacterial blight, has not been reported. In this study, we reported that one of the rice GLP genes, OsGLP2-1, was significantly induced by blast fungus. Overexpression of OsGLP2-1 quantitatively enhanced resistance to leaf blast, panicle blast and bacterial blight. The temporal and spatial expression analysis revealed that OsGLP2-1is highly expressed in leaves and panicles and sub-localized in the cell wall. Compared with empty vector transformed (control) plants, the OsGLP2-1 overexpressing plants exhibited higher levels of H2O2 both before and after pathogen inoculation. Moreover, OsGLP2-1 was significantly induced by jasmonic acid (JA). Overexpression of OsGLP2-1 induced three well-characterized defense-related genes which are associated in JA-dependent pathway after pathogen infection. Higher endogenous level of JA was also identified in OsGLP2-1 overexpressing plants than in control plants both before and after pathogen inoculation. Together, these results suggest that OsGLP2-1 functions as a positive regulator to modulate disease resistance. Its good quantitative resistance to the two major diseases in rice makes it to be a promising target in rice breeding.
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Immunity to Rice Blast Disease by Suppression of Effector-Triggered Necrosis

Immunity to Rice Blast Disease by Suppression of Effector-Triggered Necrosis | Rice Blast | Scoop.it
Highlights

•AvrPiz-t interacts and co-localizes with APIP5 in the cytoplasm
•AvrPiz-t suppresses APIP5 transcriptional activity and protein accumulation
•APIP5, a negative regulator of cell death, interacts with the NLR receptor Piz-t
•Piz-t suppresses the AvrPiz-t-mediated APIP5 turnover

Summary

Hemibiotrophic pathogens are some of the most destructive plant pathogens, causing huge economic losses and threatening global food security. Infection with these organisms often involves an initial biotrophic infection phase, during which the pathogen spreads in host tissue asymptomatically, followed by a necrotrophic phase, during which host-cell death is induced. How hemibiotrophic pathogens trigger host necrosis and how plants inhibit the transition from the biotrophic stage to the necrotrophic stage in disease symptom expression are mainly unknown. The rice blast fungus Magnaporthe oryzae spreads in rice biotrophically early during infection, but this biotrophic stage is followed by a pronounced switch to cell death and lesion formation. Here, we show that the M. oryzae effector AvrPiz-t interacts with the bZIP-type transcription factor APIP5 in the cytoplasm and suppresses its transcriptional activity and protein accumulation at the necrotrophic stage. Silencing of APIP5 in transgenic rice leads to cell death, and the phenotype is enhanced by the expression of AvrPiz-t. Conversely, Piz-t interacts with and stabilizes APIP5 to prevent necrosis at the necrotrophic stage. At the same time, APIP5 is essential for Piz-t stability. These results demonstrate a novel mechanism for the suppression of effector-triggered necrosis at the necrotrophic stage by an NLR receptor in plants.

Via Christophe Jacquet, Yunsik Kim
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Moving nitrogen to the centre of plant defence against pathogens

Moving nitrogen to the centre of plant defence against pathogens | Rice Blast | Scoop.it
When a pathogen first comes into contact with a host, it is usually nutrient starved such that rapid assimilation of host nutrients is essential for successful pathogenesis. Equally, the host may reallocate its nutrients to defence responses or away from the site of attempted infection. Exogenous application of N fertilizer can, therefore, shift the balance in favour of the host or pathogen. In line with this, increasing N has been reported either to increase or to decrease plant resistance to pathogens, which reflects differences in the infection strategies of discrete pathogens. Beyond considering only N content, the use of NO–3 or NH+4 fertilizers affects the outcome of plant–pathogen interactions. NO–3 feeding augments hypersensitive response- (HR) mediated resistance, while ammonium nutrition can compromise defence. Metabolically, NO–3 enhances production of polyamines such as spermine and spermidine, which are established defence signals, with NH+4 nutrition leading to increased γ-aminobutyric acid (GABA) levels which may be a nutrient source for the pathogen. Within the defensive N economy, the roles of nitric oxide must also be considered. This is mostly generated from NO–2 by nitrate reductase and is elicited by both pathogen-associated microbial patterns and gene-for-gene-mediated defences. Nitric oxide (NO) production and associated defences are therefore NO–3 dependent and are compromised by NH+4.
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@talbotlabexeter kicking off #BioDynamics2016 talking about the rice blast fungus magnaporthe

@talbotlabexeter kicking off #BioDynamics2016 talking about the rice blast fungus magnaporthe | Rice Blast | Scoop.it
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Spermidine, a polyamine, confers resistance to rice blast

Spermidine, a polyamine, confers resistance to rice blast | Rice Blast | Scoop.it
Polyamines are involved not only in fundamental cellular processes such as growth, differentiation, and morphogenesis, but also in various environmental stresses. We demonstrated that spermidine, a polyamine, confers resistance to rice blast accompanied by the up-regulation of marker genes for the salicylic acid-mediated signaling pathway PR1b and PBZ1 and of phytoalexin biosynthesis genes CPS4 and NOMT. This is the first report about the involvement of spermidine in rice disease resistance.
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A Genome-Wide Association Study of Field Resistance to Magnaporthe Oryzae in Rice

A Genome-Wide Association Study of Field Resistance to Magnaporthe Oryzae in Rice | Rice Blast | Scoop.it

GWAS identified 16 LAFBRs. Among them, 13 are novel and the other three are co-localized with known blast resistance regions. Seventy-four candidate genes are identified in the 16 LAFBR regions, which encode receptor-like protein kinases, transcription factors, and other defense-related proteins. Using the rice transcriptome data, compared with the rice-rice blast compatible interaction, we identified seven candidate genes that are significantly up-regulated and five genes that are significantly down-regulated in the incompatible interaction among the candidate genes.

We identified 16 LAFBRs involved in field resistance to M. oryzae and 20 cultivars that exhibit high levels of resistance in both the field and growth chamber. The resistant cultivars and the SNP markers identified in this study should be useful for marker-assisted selection of new rice cultivars that confer high levels of resistance against M. oryzae field populations.

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Current challenges of research on filamentous fungi in relation to human welfare and a sustainable bio-economy: a white paper

Current challenges of research on filamentous fungi in relation to human welfare and a sustainable bio-economy: a white paper | Rice Blast | Scoop.it
The EUROFUNG network is a virtual centre of multidisciplinary expertise in the field of fungal biotechnology. The first academic-industry Think Tank was hosted by EUROFUNG to summarise the state of the art and future challenges in fungal biology and biotechnology in the coming decade. Currently, fungal cell factories are important for bulk manufacturing of organic acids, proteins, enzymes, secondary metabolites and active pharmaceutical ingredients in white and red biotechnology. In contrast, fungal pathogens of humans kill more people than malaria or tuberculosis. Fungi are significantly impacting on global food security, damaging global crop production, causing disease in domesticated animals, and spoiling an estimated 10 % of harvested crops. A number of challenges now need to be addressed to improve our strategies to control fungal pathogenicity and to optimise the use of fungi as sources for novel compounds and as cell factories for large scale manufacture of bio-based products. This white paper reports on the discussions of the Think Tank meeting and the suggestions made for moving fungal bio(techno)logy forward.
Elsa Ballini's insight:
Worryingly, the battle lines between fungal pathogens and plants are constantly expanding, with the emergence of new hypervirulent isolates and the spread of pathogens to new geographic areas. As just one example, the devastating wheat blast disease caused by Magnaporthe oryzae was recently reported in Bangladesh. This agricultural emergency is the first case of this disease in Asia and has serious implications for wheat production throughout the continent. Pathogen geographical expansion is likely facilitated by global warming, and of extreme concern is emergence of multi fungicide resistant crop-destroying fungi. Given the serious and expanding threats fungi pose to crop and plant health, the EUROFUNG consortium advocates that improved pathogen biosecurity protocols, new fungicides, and disease resistant plants are urgent scientific and political goals.
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Glycoside Hydrolase MoGls2 Controls Asexual/Sexual Development, Cell Wall Integrity and Infectious Growth in the Rice Blast Fungus

Glycoside Hydrolase MoGls2 Controls Asexual/Sexual Development, Cell Wall Integrity and Infectious Growth in the Rice Blast Fungus | Rice Blast | Scoop.it
N-linked glycosylation is a way of glycosylation for newly synthesized protein, which plays a key role in the maturation and transport of proteins. Glycoside hydrolases (GHs) are essential in this process, and are involved in processing of N-linked glycoproteins or degradation of carbohydrate structures. Here, we identified and characterized MoGls2 in Magnaporthe oryzae, which is a yeast glucosidase II homolog Gls2 and is required for trimming the final glucose in N-linked glycans and normal cell wall synthesis. Target deletion of MoGLS2 in M. oryzae resulted in a reduced mycelial growth, an increased conidial production, delayed conidial germination and loss the ability of sexual reproduction. Pathogenicity assays revealed that the ΔMogls2 mutant showed significantly decreased in virulence and infectious growth. Further studies showed that the mutant was less sensitive to salt and osmotic stress, and increased sensitivity to cell wall stresses. Additionally, the ΔMogls2 mutant showed a defect in cell wall integrity. Our results indicate that MoGls2 is a key protein for the growth and development of M. oryzae, involving in the regulation of asexual/sexual development, stress response, cell wall integrity and infectious growth.
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Co-delivery of cell-wall-forming enzymes in the same vesicle for coordinated fungal cell wall formation

Co-delivery of cell-wall-forming enzymes in the same vesicle for coordinated fungal cell wall formation | Rice Blast | Scoop.it
Fungal cells are surrounded by an extracellular cell wall. This complex matrix of proteins and polysaccharides protects against adverse stresses and determines the shape of fungal cells. The polysaccharides of the fungal wall include 1,3-β-glucan and chitin, which are synthesized by membrane-bound synthases at the growing cell tip. A hallmark of filamentous fungi is the class V chitin synthase, which carries a myosin-motor domain. In the corn smut fungus Ustilago maydis, the myosin-chitin synthase Mcs1 moves to the plasma membrane in secretory vesicles, being delivered by kinesin-1 and myosin-5. The myosin domain of Mcs1 enhances polar secretion by tethering vesicles at the site of exocytosis. It remains elusive, however, how other cell-wall-forming enzymes are delivered and how their activity is coordinated post secretion. Here, we show that the U. maydis class VII chitin synthase and 1,3-β-glucan synthase travel in Mcs1-containing vesicles, and that their apical secretion depends on Mcs1. Once in the plasma membrane, anchorage requires enzyme activity, which suggests co-synthesis of chitin and 1,3-β-glucan polysaccharides at sites of exocytosis. Thus, delivery of cell-wall-forming enzymes in Mcs1 vesicles ensures local foci of fungal cell wall formation.
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Comparative transcriptomics of rice and exploitation of target genes for blast infection

Comparative transcriptomics of rice and exploitation of target genes for blast infection | Rice Blast | Scoop.it

Rice microarray data analysis during blast fungus (Magnaporthe oryzae) infection is performed using bioinformatics approach.
Differentially expressed genes during different time intervals of the blast infection are identified.
Classification of the identified genes on the basis of gene ontology terms was done.
A large number of genes is identified that changes expression levels in response to infection by Magnaporthe oryzae in rice.

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Pex14/17, a filamentous fungi specific peroxin, is required for import of peroxisomal matrix proteins and full virulence of Magnaporthe oryzae

Pex14/17, a filamentous fungi specific peroxin, is required for import of peroxisomal matrix proteins and full virulence of Magnaporthe oryzae | Rice Blast | Scoop.it
Peroxisomes are ubiquitous organelles in eukaryotic cells that fulfill a variety of biochemical functions. The biogenesis of peroxisomes requires a variety of proteins named peroxins, which are encoded by PEX genes. Pex14/17 is a putative peroxin recently identified, specifically present in filamentous fungal species. Its function in peroxisomal biogenesis is still obscure and its roles in fungal pathogenicity are yet undocumented. Here, we demonstrated the contributions of Pex14/17 in the rice blast fungus Magnaporthe oryzae (Mopex14/17) to peroxisomal biogenesis and fungal pathogenicity by targeting gene replacement strategies. Mopex14/17 has properties of both Pex14 and Pex17 in protein sequence. Mopex14/17 is distributed at the peroxisomal membrane and is essential for efficient peroxisomal targeting of proteins containing peroxisomal targeting signal 1. The MoPEX19 deletion led to the cytoplasmic distribution of Mopex14/17, indicating the peroxisomal import of Pex14/17 depends on Pex19. The knockout mutants of MoPEX14/17 were reduced in fatty acids utilization, reactive oxygen species (ROS) degradation and cell wall integrity. Moreover, the Δmopex14/17 mutants were delayed in conidial generation and appressorial formation, and reduced in appressorial turgor accumulation and penetration ability into host plants. These defects resulted in a significant reduction of the virulence of the mutant. These data indicated that MoPEX14/17 plays crucial roles in peroxisome biogenesis and contributes to fungal development and pathogenicity. This article is protected by copyright. All rights reserved.
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A systematic view of the MLO family in rice suggests their novel roles in morphological development, diurnal responses, the light-signaling pathway, and various stress responses

A systematic view of the MLO family in rice suggests their novel roles in morphological development, diurnal responses, the light-signaling pathway, and various stress responses | Rice Blast | Scoop.it
The Mildew resistance Locus O (MLO) family is unique to plants, containing genes that were initially identified as a susceptibility factor to powdery mildew pathogens. However, little is known about the roles and functional diversity of this family in rice, a model crop plant. The rice genome has 12 potential MLO family members. To achieve systematic functional assignments, we performed a phylogenomic analysis by integrating meta-expression data obtained from public sources of microarray data and real-time expression data into a phylogenic tree. Subsequently, we identified 12 MLO genes with various tissue-preferred patterns, including leaf, root, pollen, and ubiquitous expression. This suggested their functional diversity for morphological agronomic traits. We also used these integrated transcriptome data within a phylogenetic context to estimate the functional redundancy or specificity among OsMLO family members. Here, OsMLO12 showed preferential expression in mature pollen; OsMLO4, in the root tips; OsMLO10, throughout the roots except at the tips; and OsMLO8, expression preferential to the leaves and trinucleate pollen. Of particular interest to us was the diurnal expression of OsMLO1, OsMLO3, and OsMLO8, which indicated that they are potentially significant in responses to environmental changes. In osdxr mutants that show defects in the light response, OsMLO1, OsMLO3, OsMLO8, and four calmodulin genes were down-regulated. This finding provides insight into the novel functions of MLO proteins associated with the light-responsive methylerythritol 4-phosphate pathway. In addition, abiotic stress meta-expression data and real-time expression analysis implied that four and five MLO genes in rice are associated with responses to heat and cold stress, respectively. Upregulation of OsMLO3 by Magnaporthe oryzae infection further suggested that this gene participates in the response to pathogens. Our analysis has produced fundamental information that will enhance future studies of the diverse developmental or physiological phenomena mediated by the MLO family in this model plant system.
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CONSTANS-like 9 (COL9) delays the flowering time in Oryza sativa by repressing the Ehd1 pathway

CONSTANS-like 9 (COL9) delays the flowering time in Oryza sativa by repressing the Ehd1 pathway | Rice Blast | Scoop.it
We have previously identified that the COL family member OsCOL9 can positively enhance the rice blast resistance. In the present study, we aimed to explore the functional role of OsCOL9 in modulating the photoperiodic flowering. OsCOL9 delayed the rice heading through repressing the Ehd1 pathway under both SD and LD conditions. In addition, OsRACK1 interacted with OsCOL9 in response to circadian photoperiod, which probably mediated the OsCOL9 degradation and played an important role in regulation of rice flowering.
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A New Recessive Gene Conferring Resistance Against Rice Blast

A New Recessive Gene Conferring Resistance Against Rice Blast | Rice Blast | Scoop.it
The blast resistance present in the aus type cultivar AS20-1 was shown, via an analysis of segregation in the F2 generation bred from a cross with the highly blast susceptible cultivar Aichi Asahi, to be due to the action of a single recessive gene, denoted pi66(t). The presence of pi66(t) gave an intermediate level control to plants infected with the blast pathogen isolate EHL0635. A bulked segregant analysis indicated that four microsatellite loci (SSRs) mapping to chromosome 3 were probably linked to pi66(t). Localized mapping using chromosome 3-based SSRs and Indels defined a genetic window for pi66(t), flanked by the markers F04-j2 and M19-i12, which physically equals to 27.7 and 49.0 kb, respectively, in the reference genomes of cultivars Nipponbare and 93–11. This physical interval does not harbor any major gene currently associated with disease resistance.
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The Diversification of Plant NBS-LRR Defense Genes Directs the Evolution of MicroRNAs That Target Them

The Diversification of Plant NBS-LRR Defense Genes Directs the Evolution of MicroRNAs That Target Them | Rice Blast | Scoop.it
High expression of plant nucleotide binding site leucine-rich repeat (NBS-LRR) defense genes is often lethal to plant cells, a phenotype perhaps associated with fitness costs. Plants implement several mechanisms to control the transcript level of NBS-LRR defense genes. As negative transcriptional regulators, diverse miRNAs target NBS-LRRs in eudicots and gymnosperms. To understand the evolutionary benefits of this miRNA-NBS-LRR regulatory system, we investigated the NBS-LRRs of 70 land plants, coupling this analysis with extensive small RNA data. A tight association between the diversity of NBS-LRRs and miRNAs was found. The miRNAs typically target highly duplicated NBS-LRRs. In comparison, families of heterogeneous NBS-LRRs were rarely targeted by miRNAs in Poaceae and Brassicaceae genomes. We observed that duplicated NBS-LRRs from different gene families periodically gave birth to new miRNAs. Most of these newly emerged miRNAs target the same conserved, encoded protein motif of NBS-LRRs, consistent with a model of convergent evolution for these miRNAs. By assessing the interactions between miRNAs and NBS-LRRs, we found nucleotide diversity in the wobble position of the codons in the target site drives the diversification of miRNAs. Taken together, we propose a co-evolutionary model of plant NBS-LRRs and miRNAs hypothesizing how plants balance the benefits and costs of NBS-LRR defense genes.
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Genetic structure and mating type analysis of the Pyricularia oryzae population causing widespread epidemics in southern Brazil

Blast is a major disease of rice in Brazil, the largest rice-producing country outside Asia. This study aimed to assess the genetic structure and mating-type frequency in a contemporary Pyricularia oryzae population, which caused widespread epidemics during the 2012/13 season in the Brazilian lowland subtropical region. Symptomatic leaves and panicles were sampled at flooded rice fields in the states of Rio Grande do Sul (RS, 34 fields) and Santa Catarina (SC, 21 fields). The polymorphism at ten simple sequence repeats (SSR or microsatellite) loci and the presence of MAT1-1 or MAT1-2 idiomorphs were assessed in a population comprised of 187 isolates. Only the MAT1-2 idiomorph was found and 162 genotypes were identified by the SSR analysis. A discriminant analysis of principal components (DAPC) of SSR data resolved four genetic groups, which were strongly associated with the cultivar of origin of the isolates. There was high level of genotypic diversity and moderate level of gene diversity regardless whether isolates were grouped in subpopulations based on geographic region, cultivar host or cultivar within region. While regional subpopulations were weakly differentiated, high genetic differentiation was found among subpopulations comprised of isolates from different cultivars. The data suggest that the rice blast pathogen population in southern Brazil is comprised of clonal lineages that are adapting to specific cultivar hosts. Farmers should avoid the use of susceptible cultivars over large areas and breeders should focus at enlarging the genetic basis of new cultivars.
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Wheat blast: histopathology and transcriptome reprogramming in response to adapted and nonadapted Magnaporthe isolates

Wheat blast: histopathology and transcriptome reprogramming in response to adapted and nonadapted Magnaporthe isolates | Rice Blast | Scoop.it
Summary 

• Blast disease (causal agent Magnaporthe oryzae) has presented as a new and serious field disease of wheat in South America. Here, we investigated the responses of wheat to both adapted and nonadapted isolates of the blast fungus Magnaporthe, examining cellular defence and transcriptional changes. 
• Resistance towards the nonadapted isolate was associated with the formation of appositions, here termed halos, beneath attempted Magnaporthe grisea penetration sites that wheat-adapted, M. oryzae isolates were able to breach. 
• Transcriptome analysis indicated extensive transcriptional reprogramming following inoculation with both wheat-adapted and nonadapted isolates of Magnaporthe. Functional annotation of many of the differentially expressed transcripts classified into the categories: cell rescue and defence, plant metabolism, cellular transport and regulation of transcription (although a significant number of transcripts remain unclassified). 
• Defence-related transcripts induced in common by adapted and nonadapted isolates were differentially regulated in response to M. oryzae and M. grisea isolates over time. Differential expression of genes involved in cellular transport indicated the importance of this process in plant defence. Functional characterisation of these transcripts and their role in defence may eventually lead to the identification of broad-spectrum resistance mechanisms in wheat towards Magnaporthe.

Via Yogesh Gupta
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Roles of Rack1 Proteins in Fungal Pathogenesis

Roles of Rack1 Proteins in Fungal Pathogenesis | Rice Blast | Scoop.it
Pathogenic fungi cause diseases on various organisms. Despite their differences in life cycles, fungal pathogens use well-conserved proteins and pathways to regulate developmental and infection processes. In this review, we focus on Rack1, a multifaceted scaffolding protein involved in various biological processes. Rack1 is well conserved in eukaryotes and plays important roles in fungi, though limited studies have been conducted. To accelerate the study of Rack1 proteins in fungi, we review the functions of Rack1 proteins in model and pathogenic fungi and summarize recent progress on how Rack1 proteins are involved in fungal pathogenesis.
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Neurons show the path: tip-to-nucleus communication in filamentous fungal development and pathogenesis

Multiple fungal species penetrate substrates and accomplish host invasion through the fast, permanent and unidirectional extension of filamentous cells known as hyphae. Polar growth of hyphae results, however, in a significant increase in the distance between the polarity site, which also receives the earliest information about ambient conditions, and nuclei, where adaptive responses are executed. Recent studies demonstrate that these long distances are overcome by signal transduction pathways which convey sensory information from the polarity site to nuclei, controlling development and pathogenesis. The present review compares the striking connections of the mechanisms for long-distance communication in hyphae with those from neurons, and discusses the importance of their study in order to understand invasion and dissemination processes of filamentous fungi, and design strategies for developmental control in the future.
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Effect of different leaf wetness durations and temperatures on incubation period and development of leaf blast disease of basmati rice

Effect of duration of leaf wetness on incubation period and development of rice leaf blast revealed that a minimum of 12 hours of leaf wetness was required for infection and symptoms appeared within 7 days of incubation period. The incubation period decreased while disease severity increased significantly with increase in leaf wetness from 12 to 48 hours. A positive correlation between leaf wetness duration and disease severity was observed. Maximum increase in lesion length was recorded at 25°C followed by 20°C. Increase in lesion length was minimum at 10°C.
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MoRad6-mediated ubiquitination pathways are essential for development and pathogenicity in Magnaporthe oryzae

MoRad6-mediated ubiquitination pathways are essential for development and pathogenicity in Magnaporthe oryzae | Rice Blast | Scoop.it
The ubiquitin system modulates protein functions through targeting substrates for ubiquitination. Here, E2 conjugating enzyme MoRad6-related ubiquitination pathways are identified and analyzed in Magnaporthe oryzae, the causal agent of rice blast disease. Disruption of MoRad6 leads to severe defects in growth, sporulation, conidial germination, appressorium formation, and plant infection. To depict the functions of MoRad6, three putative ubiquitin ligases, MoRad18, MoBre1, and MoUbr1, are also characterized. Deletion of MoRad18 causes minor phenotypic changes, while MoBre1 is required for growth, conidiation and pathogenicity in M. oryzae. Defects in ΔMobre1 likely resulted from the reduction in di- and tri-methylation level of Histone 3 lysine 4 (H3K4). Notably, MoUbr1 is crucial for conidial adhesion and germination, possibly by degrading components of cAMP/PKA and MAPK Pmk1 signaling pathways via the N-end rule pathway. Germination failure of ΔMoubr1 conidia could be rescued by elevation of cAMP level or enhanced Pmk1 phosphorylation resulting from further deletion of MoIra1, the M. oryzae homolog of yeast Ira1/2. These reveal vital effects of cAMP/PKA and MAPK Pmk1 signaling on conidial germination in M. oryzae. Altogether, our results suggest that MoRad6-mediated ubiquitination pathways are essential for the infection-related development and pathogenicity of M. oryzae.
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ISIde: A rice modelling platform for in silico ideotyping

ISIde: A rice modelling platform for in silico ideotyping | Rice Blast | Scoop.it

We develop a modelling platform explicitly dedicated to in silico ideotyping studies.
Ideotypes can be improved for resistance/tolerance traits to biotic/abiotic stress.
Ideotypes are evaluated over entire districts and under climate change scenarios.
Results are useful to identify key traits for specific production districts.
A case study involving heat stress tolerance illustrates the platform capabilities.

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Tweet from @annaliisalaine The name you give a pathogen is important for how it will be quarantined #WPP16

Tweet from @annaliisalaine The name you give a pathogen is important for how it will be quarantined #WPP16 | Rice Blast | Scoop.it
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