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Characterization of a newly identified rice chitinase-like protein (OsCLP) homologous to xylanase inhibitor

Characterization of a newly identified rice chitinase-like protein (OsCLP) homologous to xylanase inhibitor | Rice Blast | Scoop.it

During rice blast fungal attack, plant xylanase inhibitor proteins (XIPs) that inhibit fungal xylanase activity are believed to act as a defensive barrier against fungal pathogens.  The transcription and translation of OsCLP were highly induced when rice was exposed to pathogens in an incompatible interaction. In addition, exogenous treatment with OsCLP affected the growth of the basidiomycete fungus Rhizoctonia solani through degradation of the hyphal cell wall. These data suggest that OsCLP, which has chitinase activity, may play an important role in plant defenses against pathogens.

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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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Transposon-Mediated NLR Exile to the Pollen Allows Rice Blast Resistance without Yield Penalty

Transposon-Mediated NLR Exile to the Pollen Allows Rice Blast Resistance without Yield Penalty | Rice Blast | Scoop.it
In crop breeding, the goal is to maximize yield and disease resistance. In this spotlight, we highlight an elegant case of NLR-mediated durable resistance in rice, which is effective against the devastating fungus Magnaporthe oryzae, but does not involve yield penalty. The genetic and molecular dissection of this broad-spectrum resistance has unraveled a fascinating epigenetic regulatory mechanism balancing blast resistance and yield that opens exciting new perspectives for crop improvement.
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Dissection of broad-spectrum resistance of the Thai rice variety Jao Hom Nin conferred by two resistance genes against rice blast

JHN showed broad spectrum resistance against Thai and Philippine rice blast isolates. As this study demonstrated, the combination of two resistance genes, Pish-J and Pi7-J, in JHN, with each controlling broad-spectrum resistance to rice blast disease, explains the high level of resistance. Thus, the combination of Pish and Pi7 can provide a practical scheme for breeding durable resistance in rice against rice blast disease.
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The cyclin dependent kinase subunit Cks1 is required for infection‐associated development of the rice blast fungus Magnaporthe oryzae

The cyclin dependent kinase subunit Cks1 is required for infection‐associated development of the rice blast fungus Magnaporthe oryzae | Rice Blast | Scoop.it
Cell cycle regulation is pivotal for proper cell division and cellular differentiation in eukaryotic cells. The central regulators that govern eukaryotic cell cycle progression are cyclin-dependent kinases (CDKs) and their partners. Here, we report that Magnaporthe oryzae CKS1 encodes a cyclin-dependent kinase subunit, which plays a significant role in regulation of plant infection. We demonstrate that CKS1 is a functional homolog of CKS1/SUC1 and can physically interact with the CDK protein Cdc28, and Som1, a downstream regulator of the cyclic AMP-dependent Protein Kinase A pathway. CKS1 deletion mutants are severely impaired in hyphal growth, sexual reproduction, melanin pigmentation and conidiogenesis. Cks1 mutants are able to form appressoria from hyphal tips, but these are unable to re-polarize, and rice infection is impaired. CKS1 also affects chitin and glucan synthase activity during cell wall differentiation and fungal hydrophobin function. CKS1, therefore, encodes a conserved CDK-binding partner, essential for appressorium-mediated plant infection by the rice blast fungus.
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Conceptual Architecture and Service-Oriented Implementation of a Regional Geoportal for Rice Monitoring

Agricultural monitoring has greatly benefited from the increased availability of a wide variety of remote-sensed satellite imagery, ground-sensed data (e.g., weather station networks) and crop models, delivering a wealth of actionable information to stakeholders to better streamline and improve agricultural practices. Nevertheless, as the degree of sophistication of agriculture monitoring systems increases, significant challenges arise due to the handling and integration of multi-scale data sources to present information to decision-makers in a way which is useful, understandable and user friendly. To address these issues, in this article we present the conceptual architecture and service-oriented implementation of a regional geoportal, specifically focused on rice crop monitoring in order to perform unified monitoring with a supporting system at regional scale. It is capable of storing, processing, managing, serving and visualizing monitoring and generated data products with different granularity and originating from different data sources. Specifically, we focus on data sources and data flow, and their importance for and in relation to different stakeholders. In the context of an EU-funded research project, we present an implementation of the regional geoportal for rice monitoring, which is currently in use in Europe’s three largest rice-producing countries, Italy, Greece and Spain
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Characterization and evaluation of rice blast resistance of Chinese indica hybrid rice parental lines

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

Subcellular compartmentation, interdependency and dynamics of the cyclic AMP‐dependent PKA subunits during pathogenic differentiation in rice blast | Rice Blast | Scoop.it
The cAMP-dependent PKA signalling plays a central role in growth, asexual development and pathogenesis in fungal pathogens. Here, we functionally characterised RPKA, the regulatory subunit of cAMP/PKA and studied the dynamics and organisation of the PKA subunits in the rice blast pathogen Magnaporthe oryzae. The RPKA subunit was essential for proper vegetative growth, asexual sporulation and surface hydrophobicity in M. oryzae. A spontaneous suppressor mutation, SMR19, that restored growth and conidiation in the RPKA deletion mutant was isolated and characterised. SMR19 enhanced conidiation and appressorium formation but failed to suppress the pathogenesis defects in rpkAΔ. The PKA activity was undetectable in the mycelial extracts of SMR19, which showed a single mutation (val242leu) in the highly conserved active site of the catalytic subunit (CPKA) of cAMP/PKA. The two subunits of cAMP/PKA showed different subcellular localisation patterns with RpkA being predominantly nucleocytoplasmic in conidia, while CpkA was largely cytosolic and/or vesicular. The CpkA anchored RpkA in cytoplasmic vesicles, and localisation of PKA in the cytoplasm was governed by CpkA in a cAMP-dependant or independent manner. We show that there exists a tight regulation of PKA subunits at the level of transcription, and the cAMP signalling is differentially compartmentalised in a stage-specific manner in rice blast.
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International Congress of Plant Pathology 2018

International Congress of Plant Pathology 2018 | Rice Blast | Scoop.it
International Congress of Plant Pathology (ICPP) 2018: Plant Health in A Global Economy

Leading experts from around the world will present the latest advances and innovations, celebrate progress, and set a vision for assuring plant health in a global economy. The vision of the Congress – An engaged world community of plant health scientists advancing knowledge for a safe, affordable, secure supply of food, feed, and fiber for a growing population – reflects the broad and unique position plant pathology holds within the international community of scientists.
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RESISTANCE TO POWDERY MILDEW8.1 boosts pattern‐triggered immunity against multiple pathogens in Arabidopsis and rice

RESISTANCE TO POWDERY MILDEW8.1 boosts pattern‐triggered immunity against multiple pathogens in Arabidopsis and rice | Rice Blast | Scoop.it
The Arabidopsis gene RESISTANCE TO POWDERY MILDEW8.1 (RPW8.1) confers resistance to virulent fungal and oomycete pathogens that cause powdery mildew and downy mildew, respectively. However, the underlying mechanism remains unclear. Here, we show that ectopic expression of RPW8.1 boosts pattern-triggered immunity (PTI) resulting in enhanced resistance against different pathogens in both Arabidopsis and rice. In Arabidopsis, transcriptome analysis revealed that ectopic expression of RPW8.1-YFP constitutively up-regulates expression of many pathogen-associated molecular pattern-(PAMP-) inducible genes. Consistently, upon PAMP application, the transgenic line expressing RPW8.1-YFP exhibited more pronounced PTI responses such as callose deposition, production of reactive oxygen species, expression of defense-related genes and hypersensitive response-like cell death. Accordingly, the growth of a virulent bacterial pathogen was significantly inhibited in the transgenic lines expressing RPW8.1-YFP. Conversely, impairment of the PTI signaling pathway from PAMP cognition to the immediate downstream relay of phosphorylation abolished or significantly compromised RPW8.1-boosted PTI responses. In rice, heterologous expression of RPW8.1-YFP also led to enhanced resistance to the blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) and the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). Taken together, our data suggest a surprising mechanistic connection between RPW8.1 function and PTI, and demonstrate the potential of RPW8.1 as a transgene for engineering disease resistance across wide taxonomic lineages of plants.
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Fungal manipulation of hormone-regulated plant defense

Fungal manipulation of hormone-regulated plant defense | Rice Blast | Scoop.it
Fungi have adapted to diverse habitats and ecological niches, including the complex plant systems. Success of the pathogenic or symbiotic fungi in colonizing the plant tissue depends on their ability to modulate the host defense signaling [1]. Strategies that impart such abilities in fungi include the use of effector proteins that directly disrupt phytohormone-based defense signaling pathways and/or the deployment of mimics of specific plant molecules to evade recognition and the subsequent host immune response [1, 2]. Recent exciting findings have provided insight into a novel strategy whereby the fungal pathogens utilize the endogenous phytohormone-mimics and/or relevant metabolic enzymes to suppress host immunity. These studies strongly suggest that fungal metabolites, in addition to effector proteins, can chemically shape and maintain distinct pathogenic or symbiotic interkingdom relationships between plants and fungi.

Via Christophe Jacquet
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Molecular marker-based validation of blast resistance gene Pi54 and identification of potential donors in temperate high altitude rice (Oryza sativa L.)

pathogen races prevailing in a certain area, rate of pathogen evolution, genetic background of a host and few others. Pi54 is a major gene showing resistance to Magnaporthe populations in North-west Himalayas. In search of novel temperate donors suitable to high altitudes, a set of germplasm was screened using gene based markers for Pi54. Eighty three exotic and indigenous germplasm lines were genotyped using gene based markers and also validated for disease reaction using Pi54 gene specific isolate namely, Mo-nwi-kash-32. Nine out of 83 germplasm lines amplified resistance specific alleles with both the markers Pi54 MAS and Pikh-STS. All these lines expressed resistance against the said diagnostic isolate, thereby validating the possible presence of gene in the lines. Further validation using more number of isolates and sequence analysis will help in mining useful alleles for this gene.
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A special issue on Fusarium head blight and wheat blast

A special issue on Fusarium head blight and wheat blast | Rice Blast | Scoop.it
We were pleased, around two years ago, to take the lead in organizing two important international conferences: the 5th International Symposium on Fusarium Head Blight (ISFHB) and the 2nd International Workshop on Wheat Blast (IWWB). For the first time offered as a joint meeting, the conferences were held at Costão do Santinho Resort, Florianópolis, Brazil, from 6 to 9 April 2016. The beautiful venue by the Praia do Santinho on the Florianopolis Island, certainly added to the success of the meeting. The participation in both conferences and the scientific contribution were overwhelming: 210 attendees from 38 countries (110 from Brazil, 141 abstracts, 20 keynote lectures, 24 invited talks and 97 poster presentations by researchers from all over the world (Fig. 1). A Book of Abstracts was organized and videos of some of the keynote presentations were recorded and are freely available (http://scabandblastofwheat2016.org).
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MoCAP proteins regulated by MoArk1-mediated phosphorylation coordinate endocytosis and actin dynamics to govern development and virulence of Magnaporthe oryzae

MoCAP proteins regulated by MoArk1-mediated phosphorylation coordinate endocytosis and actin dynamics to govern development and virulence of Magnaporthe oryzae | Rice Blast | Scoop.it
Actin organization is a conserved cellular process that regulates the growth and development of eukaryotic cells. It also governs the virulence process of pathogenic fungi, such as the rice blast fungus Magnaporthe oryzae, with mechanisms not yet fully understood. In a previous study, we found that actin-regulating kinase MoArk1 displays conserved functions important in endocytosis and actin organization, and MoArk1 is required for maintaining the growth and full virulence of M. oryzae. To understand how MoArk1 might function, we identified capping protein homologs from M. oryzae (MoCAP) that interact with MoArk1 in vivo. MoCAP is heterodimer consisting of α and β subunits MoCapA and MoCapB. Single and double deletions of MoCAP subunits resulted in abnormal mycelial growth and conidia formation. The ΔMocap mutants also exhibited reduced appressorium penetration and invasive hyphal growth within host cells. Furthermore, the ΔMocap mutants exhibited delayed endocytosis and abnormal cytoskeleton assembly. Consistent with above findings, MoCAP proteins interacted with MoAct1, co-localized with actin during mycelial development, and participated in appressorial actin ring formation. Further analysis revealed that the S85 residue of MoCapA and the S285 residue of MoCapB were subject to phosphorylation by MoArk1 that negatively regulates MoCAP functions. Finally, the addition of exogenous phosphatidylinositol 4,5-bisphosphate (PIP2) failed to modulate actin ring formation in ΔMocap mutants, in contrast to the wild-type strain, suggesting that MoCAP may also mediate phospholipid signaling in the regulation of the actin organization. These results together demonstrate that MoCAP proteins whose functions are regulated by MoArk1 and PIP2 are important for endocytosis and actin dynamics that are directly linked to growth, conidiation and pathogenicity of M. oryzae.
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Evolutionary relationships and expression analysis of EUL domain proteins in rice ( Oryza sativa )

Evolutionary relationships and expression analysis of EUL domain proteins in rice ( Oryza sativa ) | Rice Blast | Scoop.it
The presence of EULs throughout the plant kingdom and the high degree of sequence conservation in the EUL domain suggest that these proteins serve an important function in the plant cell. Analysis of the promoter region of the rice EUL genes revealed a diversity of stress responsive elements. Furthermore analysis of the expression profiles of the EUL genes confirmed that they are differentially regulated in response to several types of stress. These data suggest a potential role for the EULs in plant stress signaling and defense.
Elsa Ballini's insight:
At present, there are only a few reports that show the involvement of OsEUL genes in response to pathogen attack. qRT-PCR experiments and microarray data revealed that transcript levels for some OsEULs are upregulated after infection of rice with Xanthomonas oryzae pv. oryzae (OsEULD1B, OsEULD2), Magnaporthe oryzae (OsEULD2) or root knot nematodes (Meloidogyne graminicola) (OsEULD2) (Al Atalah et al. 2013; Kyndt et al. 2012). In line with this, several WRKY transcription factors with binding sites identified in the OsEUL promoters are regulated by diverse biotic stresses. For example, WRKY71 for whom a binding site was identified in the OsEULS2 promoter was upregulated upon infection with Magnaporthe grisea (Berri et al. 2009). Other WRKY transcription factors with binding sites in the OsEULS2 promoter were upregulated upon infection with Xanthomonas oryzae (Zhou et al. 2010) and Magnaporthe oryzae (Marcel et al. 2010).
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NLR diversity, helpers and integrated domains: making sense of the NLR IDentity

NLR diversity, helpers and integrated domains: making sense of the NLR IDentity | Rice Blast | Scoop.it
Plant innate immunity relies on genetically predetermined repertoires of immune receptors to detect pathogens and trigger an effective immune response. A large proportion of these receptors are from the Nucletoide Binding Leucine Rich Repeat (NLR) gene family. As plants live longer than most pathogens, maintaining diversity of NLRs and deploying efficient ‘pathogen traps’ is necessary to withstand the evolutionary battle. In this review, we summarize the sources of diversity in NLR plant immune receptors giving an overview of genomic, regulatory as well as functional studies, including the latest concepts of NLR helpers and NLRs with integrated domains.

Via Christophe Jacquet, Jennifer Mach
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The ArfGAP protein MoGlo3 regulates the development and pathogenicity of Magnaporthe oryzae

The ArfGAP protein MoGlo3 regulates the development and pathogenicity of Magnaporthe oryzae | Rice Blast | Scoop.it
The ADP ribosylation factor (Arf) and the coat protein complex I (COPI) are both involved in vesicle transport. Together with GTPase-activating proteins (ArfGAPs) and guanine exchange factors (ArfGEFs) that regulate the activity of Arf, they govern vesicle formation, COPI trafficking, and the maintenance of the Golgi complex. In an ongoing effort to study the role of membrane trafficking in pathogenesis of the rice blast fungus Magnaporthe oryzae, we identified MoGlo3 as an ArfGAP protein that is homologous to Glo3p of the budding yeast Saccharomyces cerevisiae. As suspected, MoGlo3 partially complements the function of yeast Glo3p. Consistent with findings in S. cerevisiae, MoGlo3 is localized to the Golgi and that the localization is dependent on the conserved BoCCS domain. We found that MoGlo3 is highly expressed during conidiation and early infection stages, and is required for vegetative growth, conidial production, and sexual development. We further found that the ΔMoglo3 mutant is defective in endocytosis, scavenging of the reactive oxygen species (ROS), and in the response to endoplasmic reticulum (ER) stress. The combined effects result in failed appressorium function and decreased pathogenicity. Moreover, we provided evidence showing that the domains including the GAP, BoCCS and GRM are all important for normal MoGlo3 functions. Our studies further illustrate the importance of normal membrane trafficking in the physiology and pathogenicity of the rice blast fungus. This article is protected by copyright. All rights reserved.
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Immunity and starvation: new opportunities to elevate disease resistance in crops

Immunity and starvation: new opportunities to elevate disease resistance in crops | Rice Blast | Scoop.it
Plants restrict sugar mobilization to limit microbial colonization.


Successful pathogens modulate sugar extraction, hydrolysis, and uptake.


Pathogen adaptability relies on immune modulation machinery.


Blocking pathogen access to nutrients is a promising strategy to control diseases
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Small RNA Functions Are Required for Growth and Development of Magnaporthe oryzae

Small RNA Functions Are Required for Growth and Development of Magnaporthe oryzae | Rice Blast | Scoop.it
RNA interference (RNAi) is conserved in eukaryotic organisms, and it has been well studied in many animal and plant species and some fungal species, yet it is not well studied in fungal plant pathogens. In the rice blast fungus Magnaporthe oryzae, we examined small RNA (sRNA) and their biogenesis in the context of growth and pathogenicity. Through genetic and genomic analyses, we demonstrate that loss of a single gene encoding Dicer, RNA-dependent RNA polymerase, or Argonaute reduces sRNA levels. These three proteins are required for the biogenesis of sRNA-matching genome-wide regions (coding regions, repeats, and intergenic regions). The loss of one Argonaute reduced both sRNA and fungal virulence on barley leaves. Transcriptome analysis of multiple mutants revealed that sRNA play an important role in transcriptional regulation of repeats and intergenic regions in M. oryzae. Together, these data support that M. oryzae sRNA regulate developmental processes including, fungal growth and virulence.


Via Steve Marek, Xiaodong Wang
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The receptor-like cytoplasmic kinase BSR1 mediates chitin-induced defense signaling in rice cells

The receptor-like cytoplasmic kinase BSR1 mediates chitin-induced defense signaling in rice cells | Rice Blast | Scoop.it
Broad-Spectrum Resistance 1 (BSR1) encodes a rice receptor-like cytoplasmic kinase, and enhances disease resistance when overexpressed. Rice plants overexpressing BSR1 are highly resistant to diverse pathogens, including rice blast fungus. However, the mechanism responsible for this resistance has not been fully characterized. To analyze the BSR1 function, BSR1-knockout (BSR1-KO) plants were generated using a clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system. Experiments using suspension-cultured cells revealed that defense responses including H2O2 production (i.e. oxidative burst) and expression of defense-related genes induced by autoclaved conidia of the rice blast fungus significantly decreased in BSR1-KO cells. Furthermore, a treatment with chitin oligomers which function as microbe-associated molecular patterns (MAMPs) of the rice blast fungus resulted in considerably suppressed defense responses in BSR1-KO cells. These results suggest that BSR1 is important for the rice innate immunity triggered by the perception of chitin.

Via Jonathan Plett
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CRISPR system in filamentous fungi: Current achievements and future directions

CRISPR system in filamentous fungi: Current achievements and future directions | Rice Blast | Scoop.it

Different strategies for genome manipulation efficiency of CRISPR/Cas9 were discussed.
CRISPR/Cas9 can decode the filamentous fungal pathogenesis.
CRISPR system can make the waste profitable.
CRISPR/Cas9 system can stimulate novel drug discovery using synthetic biology.
Nuclease-deficient Cas9 can redirect the metabolic flux by synthetic gene circuits.

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The Role of the Fungal Cell Wall in the Infection of Plants

The Role of the Fungal Cell Wall in the Infection of Plants | Rice Blast | Scoop.it
The polysaccharide-rich wall, which envelopes the fungal cell, is pivotal to the maintenance of cellular integrity and for the protection of the cell from external aggressors − such as environmental fluxes and during host infection. This review considers the commonalities in the composition of the wall across the fungal kingdom, addresses how little is known about the assembly of the polysaccharide matrix, and considers changes in the wall of plant-pathogenic fungi during on and in planta growth, following the elucidation of infection structures requiring cell wall alterations. It highlights what is known about the phytopathogenic fungal wall and what needs to be discovered.
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Cyclophilins: Less Studied Proteins with Critical Roles in Pathogenesis

Cyclophilins: Less Studied Proteins with Critical Roles in Pathogenesis | Rice Blast | Scoop.it
Cyclophilins (EC 5.2.1.8) (CYPs) belong to a subgroup of proteins known as immunophilins, which also include FK-506 binding proteins (FKBPs) and parvulins. Members of the immunophilins have two main characteristic properties: I) peptidyl-prolyl cis-trans isomerase activity (PPIases) and II) the ability to bind immunosuppressant molecules of fungal origin. Cyclophilins are some of the most conserved proteins present in eukaryotes and prokaryotes, and they have been implicated in diverse cellular processes and responses to multiple biotic and abiotic stresses. Cyclophilins have been exploited in humans and plants extensively, but they have only recently received attention in regard to phytopathogens. In Phellinus sulphurascens and species of the genus Leptosphaeria and Phytophthora, high expression of cyclophilins was found to be related to infection. Moreover, recent studies of cyclophilins in certain phytopathogens, such as Magnaporthe oryzae, Botrytis cinerea, Cryphonectria parasitica, and Puccinia triticina, demonstrated their roles as a pathogenicity factors. In addition to pathogenicity, cyclophilins have high affinity for the immunosuppressive drug cyclosporin A (CsA), which is a potent antifungal agent. Although cyclophilins are highly conserved in phytopathogens, because they have been less studied, their role remains largely unknown. In this review, we provide detailed information on the cyclophilins in several phytopathogens, including fungi and oomycetes, as well as their role in suppressing plant immunity.
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Exploring Key Blast and Bacterial Blight Resistance Genes in Genetically Diverse Rice Accessions through Molecular and Phenotypic Evaluation

Blast and bacterial blight (BB) are the most dangerous rice (Oryza sativa L.) diseases that limit rice production significantly. Pib, Piz-t, and Pi9 are reported as key resistance genes for blast whereas Xa21, Xa4, Xa7, and xa13 are considered as important resistance genes for BB. Using gene-specific DNA markers, the presence of these resistance genes was screened in 211 diverse rice accessions originating from 26 countries. In molecular marker analyses, specific amplification patterns for the Pib and Piz-t resistance alleles were observed in 56 and 23 accessions, respectively, whereas the Pi9 resistance allele was not observed at all in these accessions. For BB, at least one BB resistance gene was present in 148 of the 211 evaluated accessions. All 211 accessions were evaluated for blast resistance using natural isolates and for BB resistance using Race 4 (PX071) and Race 6 (PX099). Among 211 accessions, 89 exhibited hypersensitive blast resistance reactions, whereas 85 and 37 accessions were rated as resistant or moderately resistance to BB Races 4 and 6, respectively. The combined analysis of molecular and phenotypic reactions (marker-trait association assay) revealed that landraces possessed rare and several desirable genes compared with breeding lines with a narrow genetic base, hence these landraces serve as the valuable source for exploring new resistance genes for crop improvement. An interesting similarity in gene distribution pattern was observed in Pib with Xa21 and in Piz-t with Xa7. The analyzed blast and BB resistance genes were in a range of combinations in different landraces and breeding lines, which can be used in gene introgression and pyramiding programs as alternative resistance sources.
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2nd IWWB – Keynote talks on Youtube on Wheat blast

Wheat blast: biology, genetics and genomics

Barbara Valent – Kansas State University (USA)

Occurrence of wheat blast in Bangladesh
Paritosh Kumar Malaker – Wheat Research Center / Bangladesh Agric. Res. Institute ( Bangladesh)

Blast Resistance In U.S Wheats
William W. Bockus – Kansas State University (USA)

Efficient breeding strategy for wheat blast disease resistance in Bolivia – use of the experience acquired on rice blast
Michel J. Vales – CIRAD UMR BGPI (France, Bolivia)

The recent emergence and evolution of the wheat blast species complex in Brazil
Paulo Ceresini – UNESP Ilha Solteira (Brazil)

Wheat blast and gray leaf spot: diseases caused by a single, genetically diverse pathogen super-population?
Mark Farman – University of Kentucky (USA)

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MoEnd3 regulates appressorium formation and virulence through mediating endocytosis in rice blast fungus Magnaporthe oryzae

MoEnd3 regulates appressorium formation and virulence through mediating endocytosis in rice blast fungus Magnaporthe oryzae | Rice Blast | Scoop.it
Eukaryotic cells respond to environmental stimuli when cell surface receptors are bound by environmental ligands. The binding initiates a signal transduction cascade that results in the appropriate intracellular responses. Studies have shown that endocytosis is critical for receptor internalization and signaling activation. In the rice blast fungus Magnaporthe oryzae, a non-canonical G-protein coupled receptor, Pth11, and membrane sensors MoMsb2 and MoSho1 are thought to function upstream of G-protein/cAMP signaling and the Pmk1 MAPK pathway to regulate appressorium formation and pathogenesis. However, little is known about how these receptors or sensors are internalized and transported into intracellular compartments. We found that the MoEnd3 protein is important for endocytic transport and that the ΔMoend3 mutant exhibited defects in efficient internalization of Pth11 and MoSho1. The ΔMoend3 mutant was also defective in Pmk1 phosphorylation, autophagy, appressorium formation and function. Intriguingly, restoring Pmk1 phosphorylation levels in ΔMoend3 suppressed most of these defects. Moreover, we demonstrated that MoEnd3 is subject to regulation by MoArk1 through protein phosphorylation. We also found that MoEnd3 has additional functions in facilitating the secretion of effectors, including Avr-Pia and AvrPiz-t that suppress rice immunity. Taken together, our findings suggest that MoEnd3 plays a critical role in mediating receptor endocytosis that is critical for the signal transduction-regulated development and virulence of M. oryzae.
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Plant growth-promoting abilities and biocontrol efficacy of Streptomyces sp. UPMRS4 against Pyricularia oryzae

Plant growth-promoting abilities and biocontrol efficacy of Streptomyces sp. UPMRS4 against Pyricularia oryzae | Rice Blast | Scoop.it

Streptomyces UPMRS4 was found to be a potential biocontrol and bioenhancer candidate for blast disease management and improving yield in rice.

UPMRS4 significantly reduced rice blast disease by 67.9% while maintaining yield attributes comparable to the uninfected plants.

UPMRS4 also significantly increased plant growth attributes and demonstrated up-regulation of defence related genes in both infected and non-infected plants.

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Functional insights into the Magnaporthe oryzae class II myosin

Functional insights into the Magnaporthe oryzae class II myosin | Rice Blast | Scoop.it

Magnaporthe oryzae adversely impacts cultivated rice and wheat in Asia, and is primarily considered economically and scientifically relevant.1-5 Callaway, E. Devastating wheat fungus appears in Asia for first time. This fungus develops intricate infection-related phenotypes that are almost exclusively observed during biotrophy, a symptomless infection strategy required for growth and feeding on living tissues. Biotrophy begins when conidia attach to the leaf surface (Fig. 1A-1-2) and germinate into germ tubes (Fig. 1A-3), which differentiate into appressoria (Fig. 1A-4). These infection structures can become highly melanized and accumulate glycerol, In turn, this generates internal turgor and mechanical force required for breaching the leaf cuticle, consequently marking the beginning of invasive hyphal growth. Key events, including the emergence of a penetration peg regulated by the transcription factor, MoGTI1and septin-mediated cytoskeleton remodeling controlled by NADPH oxidase ensue at the onset of invasion (Fig. 1A-5).1 Following this, conidiophores develop while discernable blast lesions emerge on the leaf surface (Fig. 1A-6). This symptomatic stage (necrotrophy) allows M. oryzae to thrive even after localized host cell death has commenced. Effector proteins are deployed during infection to interfere with host immunity during biotrophy and activate events leading to host cell death, and establishing necrotrophy.

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