Rice blast caused by Magnaporthe oryzae is the most destructive disease affecting the rice production (Oryza sativa), with an average global loss of 10–30% per annum. Recent reports have indicated that the fungus also inflicts blast disease on wheat (Triticum aestivum) posing a serious threat to the wheat production. Due to its easily detected infectious process and manoeuvrable genetic manipulation, M. oryzae is considered a model organism for exploring the molecular mechanism underlying fungal pathogenicity during the pathogen–host interaction. M. oryzae utilises an infectious structure called appressorium to breach the host surface by generating high turgor pressure. The appressorium development is induced by physical and chemical cues which are coordinated by the highly conserved cAMP/PKA, MAPK and calcium signalling cascades. Genes involved in the appressorium development have been identified and well studied in M. oryzae, a summary of the working gene network linking stimuli sensing and physiological transformation of appressorium is needed. This review provides a comprehensive discussion regarding the regulatory networks underlying appressorium development with particular emphasis on sensing of appressorium inducing stimuli, signal transduction, transcriptional regulation and the corresponding developmental and physiological responses. We also discussed the crosstalk and interaction of various pathways during the appressorium development.
BackgroundA number of Pyricularia species are known to infect different grass species. In the case of Pyricularia oryzae (syn. Magnaporthe oryzae), distinct populations are known to be adapted to a wide variety of grass hosts, including rice, wheat and many other grasses. The genome sizes of Pyricularia species are typical for filamentous ascomycete fungi [~ 40 Mbp for P. oryzae, and ~ 45 Mbp for P. grisea]. Genome plasticity, mediated in part by deletions promoted by recombination between repetitive elements [Genome Res 26:1091-1100, 2016, Nat Rev Microbiol 10:417-430,2012] and transposable elements [Annu Rev Phytopathol 55:483-503,2017] contributes to host adaptation. Therefore, comparisons of genome structure of individual species will provide insight into the evolution of host specificity. However, except for the P. oryzae subgroup, little is known about the gene content or genome organization of other Pyricularia species, such as those infecting Pennisetum grasses.ResultsHere, we report the genome sequence of P. penniseti strain P1609 isolated from a Pennisetum grass (JUJUNCAO) using PacBio SMRT sequencing technology. Phylogenomic analysis of 28 Magnaporthales species and 5 non-Magnaporthales species indicated that P1609 belongs to a Pyricularia subclade, which is genetically distant from P. oryzae. Comparative genomic analysis revealed that the pathogenicity-related gene repertoires had diverged between P1609 and the P. oryzae strain 70–15, including the known avirulence genes, other putative secreted proteins, as well as some other predicted Pathogen-Host Interaction (PHI) genes. Genomic sequence comparison also identified many genomic rearrangements relative to P. oryzae.ConclusionOur results suggested that the genomic sequence of the P. penniseti P1609 could be a useful resource for the genetic study of the Pennisetum-infecting Pyricularia species and provide new insight into evolution of pathogen genomes during host adaptation.Electronic supplementary materialThe online version of this article (10.1186/s12864-018-5222-8) contains supplementary material, which is available to authorized users.
BACKGROUND Sanguinarine (SAN) is a benzophenanthridine alkaloid that broadly targets a range of pathways in mammalian and fungal cells. In this study we set out to explore the molecular mechanism of sanguinarine inhibition of the fungal development and pathogenicity of Magnaporthe oryzae with the hope that sanguinarine will bolster the development of antiblast agents. RESULTS We found that the fungus exhibited a significant reduction in vegetative growth and hyphal melanization while the spores produced long germ tubes on the artificial hydrophobic surface characteristic of a defect in thigmotropic sensing when exposed to 4, 8 and 0.5 μm sanguinarine, respectively. Consistent with these findings, we observed that the genes involved in melanin biosynthesis and the fungal hydrophobin MoMPG1 were remarkably suppressed in mycelia treated with 8 μm sanguinarine. Additionally, sanguinarine inhibited appressorium formation at a dose of 1.0 μm and this defect was restored by supplementing 5 mM of exogenous cAMP. By qRT‐PCR assay we found cAMP pathway signalling genes such as MoCAP1 and MoCpkA were significantly repressed whereas MoCDTF1 and MoSOM1 were upregulated in sanguinarine‐treated strains. Furthermore, we showed that sanguinarine does not selectively inhibit vegetative growth and appressorium formation of Guy11 but also other strains of M. oryzae. Finally, treatment of sanguinarine impaired the appressorium‐mediated penetration and pathogenicity of M. oryzae in a dose‐dependent manner. CONCLUSION Based on our results we concluded that sanguinarine is an attractive antimicrobial candidate for fungicide development in the control of rice blast disease. © 2021 Society of Chemical Industry.
Peronophythora litchii is an oomycete pathogen that exclusively infects litchi, with infection stages affecting a broad range of tissues. In this study, we obtained a near chromosome-level genome assembly of P. litchii strain ZL2018 from China using Oxford Nanopore Technologies (ONT) long-read sequencing and Illumina short-read sequencing. The genome assembly was 64.15 Mb in size and consisted of 81 contigs with an N50 of 1.43 Mb and a maximum length of 4.74 Mb. Excluding 34.67% of repeat sequences, a total of 14,857 protein-coding genes were identified, among which 14,447 genes were annotated. We also predicted 306 candidate RXLR effectors in the assembly. The high-quality genome assembly and annotation resources reported in this study will provide new insight into the infection mechanisms of P. litchii.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.