scholarly journals A bacterial kinase phosphorylates OSK1 to suppress stomatal immunity in rice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shanzhi Wang ◽  
Shuai Li ◽  
Jiyang Wang ◽  
Qian Li ◽  
Xiu-Fang Xin ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Disease Susceptibility ◽  
Ectopic Expression ◽  
Adaptor Protein ◽  
Xanthomonas Oryzae ◽  
Biochemical Activity ◽  
Jasmonate Signaling ◽  
Bacterial Effectors

AbstractThe Xanthomonas outer protein C2 (XopC2) family of bacterial effectors is widely found in plant pathogens and Legionella species. However, the biochemical activity and host targets of these effectors remain enigmatic. Here we show that ectopic expression of XopC2 promotes jasmonate signaling and stomatal opening in transgenic rice plants, which are more susceptible to Xanthomonas oryzae pv. oryzicola infection. Guided by these phenotypes, we discover that XopC2 represents a family of atypical kinases that specifically phosphorylate OSK1, a universal adaptor protein of the Skp1-Cullin-F-box ubiquitin ligase complexes. Intriguingly, OSK1 phosphorylation at Ser53 by XopC2 exclusively increases the binding affinity of OSK1 to the jasmonate receptor OsCOI1b, and specifically enhances the ubiquitination and degradation of JAZ transcription repressors and plant disease susceptibility through inhibiting stomatal immunity. These results define XopC2 as a prototypic member of a family of pathogenic effector kinases and highlight a smart molecular mechanism to activate jasmonate signaling.

scholarly journals CAND1-Mediated Substrate Adaptor Recycling Is Required for Efficient Repression of Nrf2 by Keap1

2006 ◽  
Vol 26 (4) ◽  
pp. 1235-1244 ◽  
Author(s):  
Shih-Ching Lo ◽  
Mark Hannink
Keyword(s):  
Ubiquitin Ligase ◽  
Redox Homeostasis ◽  
Ectopic Expression ◽  
E3 Ubiquitin Ligase ◽  
Adaptor Protein ◽  
Bzip Transcription Factor ◽  
Ubiquitin Ligase Complex ◽  
Steady State Levels

ABSTRACT The bZIP transcription factor Nrf2 controls a genetic program that protects cells from oxidative damage and maintains cellular redox homeostasis. Keap1, a BTB-Kelch protein, is the major upstream regulator of Nrf2. Keap1 functions as a substrate adaptor protein for a Cul3-dependent E3 ubiquitin ligase complex to repress steady-state levels of Nrf2 and Nrf2-dependent transcription. Cullin-dependent ubiquitin ligase complexes have been proposed to undergo dynamic cycles of assembly and disassembly that enable substrate adaptor exchange or recycling. In this report, we have characterized the importance of substrate adaptor recycling for regulation of Keap1-mediated repression of Nrf2. Association of Keap1 with Cul3 was decreased by ectopic expression of CAND1 and was increased by small interfering RNA (siRNA)-mediated knockdown of CAND1. However, both ectopic overexpression and siRNA-mediated knockdown of CAND1 decreased the ability of Keap1 to target Nrf2 for ubiquitin-dependent degradation, resulting in stabilization of Nrf2 and activation of Nrf2-dependent gene expression. Neddylation of Cul3 on Lys 712 is required for Keap1-dependent ubiquitination of Nrf2 in vivo. However, the K712R mutant Cul3 molecule, which is not neddylated, can still assemble with Keap1 into a functional ubiquitin ligase complex in vitro. These results provide support for a model in which substrate adaptor recycling is required for efficient substrate ubiquitination by cullin-dependent E3 ubiquitin ligase complexes.

scholarly journals Microbial antagonists against plant pathogens in Iran: A review

2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Agricultural Products ◽  
Control Measures ◽  
Wide Range ◽  
Plant Disease Management ◽  
Published Research

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.

scholarly journals Spray-induced gene silencing for disease control is dependent on the efficiency of pathogen RNA uptake

2021 ◽  
Author(s):  
Lulu Qiao ◽  
Chi Lan ◽  
Luca Capriotti ◽  
Audrey Ah-Fong ◽  
Jonatan Nino Sanchez ◽  
...  
Keyword(s):  
Disease Management ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Developmental Stages ◽  
Pathogenic Fungi ◽  
Cell Types ◽  
Uptake Efficiency ◽  
Fungal Plant Pathogens ◽  
Plant Disease Management ◽  
Fungal Genes

AbstractRecent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger, and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited, and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in the pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen RNA uptake efficiency.

scholarly journals Identification of the Colletotrichum species associated with mango diseases and a universal LAMP detection method for C. gloeosporioides species complex

2021 ◽  
pp. 49-60
Author(s):  
Yukako Hattori ◽  
Chiharu Nakashima ◽  
Shunsuke Kitabata ◽  
Kosuke Naito ◽  
Ayaka Hieno ◽  
...  
Keyword(s):  
Species Complex ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Colletotrichum Gloeosporioides ◽  
Detection Method ◽  
Coding Region ◽  
Gene Coding ◽  
Detectable Range ◽  
Amplification Assay ◽  
Colletotrichum Gloeosporioides Species Complex

Abstract: The Colletotrichum gloeosporioides species complex contains plant pathogens linked to Anthracnose diseases afflicting various crops. In this study, we designed a loop-mediated isothermal amplification assay (LAMP) primer set based on calmodulin gene coding region sequences from taxonomically authorized isolates of species from this complex to rapidly detect the presence of fungi associated with Anthracnose diseases. This test can be employed at any point between cultivation and sale. Moreover, we examined the specificity and detectable range of this primer set using isolates selected from species of the genus Colletotrichum. This test was able to specifically detect members of the C. gloeosporioides species complex, including C. gloeosporioides, C. aotearoa, C. fructicola, C. horii, C. kahawae, C. musae, C. siamense, C. theobromicola, and C. tropicale. Key Words: Anthracnose, diagnosis, phylogeny, plant disease

scholarly journals Biochar and Trichoderma spp. in management of plant diseases caused by soilborne fungal pathogens: a review and perspective

2021 ◽  
Vol 10 (15) ◽  
pp. e296101522465
Author(s):  
Erika Valente de Medeiros ◽  
Lucas Figueira da Silva ◽  
Jenifer Sthephanie Araújo da Silva ◽  
Diogo Paes da Costa ◽  
Carlos Alberto Fragoso de Souza ◽  
...  
Keyword(s):  
Soil Properties ◽  
Fungal Pathogens ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Management Tool ◽  
Production Plant ◽  
Trichoderma Spp ◽  
Health Concept ◽  
Plant Disease Management

A better understanding of the use of biochar with Trichoderma spp. (TRI), considered the most studied tool for biological control, would increase our ability to set priorities. However, no studies exist using the two inputs on plant disease management. Here, we hypothesized that biochar and TRI would be used for the management of soilborne plant pathogens, mainly due to changes in soil properties and its interactions. To test this hypothesis, this review assesses papers that used biochar and TRI against plant diseases and we summarize the handling mechanisms for each input. Biochar acts by mechanisms: induction to plant resistance, sorption of allelopathic and fungitoxic compounds, increase of beneficial microorganisms, changes the soil properties that promote health and nutrient availability. Trichoderma as biocontrol agents by different mechanisms: mycoparasitism, enzyme and secondary metabolic production, plant promoter agent, natural decomposition agent, and biological agent of bioremediation. Overall, our findings expand our knowledge about the reuse of wastes transformed in biochar combined with Trichoderma has potential perspective to formulate products as alternative management tool of plant disease caused by soilborne fungal pathogen and add important information that can be suitable for development of strategy for use in the global health concept.

scholarly journals The Green Revolution shaped the population structure of the rice pathogen Xanthomonas oryzae pv. oryzae

2019 ◽  
Vol 14 (2) ◽  
pp. 492-505 ◽  
Author(s):  
Ian Lorenzo Quibod ◽  
Genelou Atieza-Grande ◽  
Eula Gems Oreiro ◽  
Denice Palmos ◽  
Marian Hanna Nguyen ◽  
...  
Keyword(s):  
Population Structure ◽  
Plant Pathogens ◽  
Crop Improvement ◽  
Green Revolution ◽  
Agricultural Practices ◽  
The Philippines ◽  
Xanthomonas Oryzae ◽  
Rice Varieties ◽  
Evolutionary Trajectory ◽  
The Impact

Abstract The impact of modern agriculture on the evolutionary trajectory of plant pathogens is a central question for crop sustainability. The Green Revolution replaced traditional rice landraces with high-yielding varieties, creating a uniform selection pressure that allows measuring the effect of such intervention. In this study, we analyzed a unique historical pathogen record to assess the impact of a major resistance gene, Xa4, in the population structure of Xanthomonas oryzae pv. oryzae (Xoo) collected in the Philippines in a span of 40 years. After the deployment of Xa4 in the early 1960s, the emergence of virulent pathogen groups was associated with the increasing adoption of rice varieties carrying Xa4, which reached 80% of the total planted area. Whole genomes analysis of a representative sample suggested six major pathogen groups with distinctive signatures of selection in genes related to secretion system, cell-wall degradation, lipopolysaccharide production, and detoxification of host defense components. Association genetics also suggested that each population might evolve different mechanisms to adapt to Xa4. Interestingly, we found evidence of strong selective sweep affecting several populations in the mid-1980s, suggesting a major bottleneck that coincides with the peak of Xa4 deployment in the archipelago. Our study highlights how modern agricultural practices facilitate the adaptation of pathogens to overcome the effects of standard crop improvement efforts.

scholarly journals Genetic Diversity of a Brazilian Strain Collection of Xanthomonas citri subsp. citri Based on the Type III Effector Protein Genes

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 193-203 ◽  
Author(s):  
F. J. Jaciani ◽  
J. A. Ferro ◽  
M. I. T. Ferro ◽  
C. Vernière ◽  
O. Pruvost ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plant Pathogens ◽  
Citrus Canker ◽  
Integrated Approach ◽  
Pcr Analysis ◽  
Type Iii Effector ◽  
Type Iii ◽  
Strain Collection ◽  
Bacterial Effectors ◽  
Dna Primers

Exclusion and eradication or management based on an integrated approach with less susceptible varieties, copper-based bactericides, and windbreaks are the two main strategies used to prevent or control citrus canker. Field tolerance or resistance to citrus canker is not found in the most important commercial sweet orange cultivars, and pathogen-derived resistance has been developed and applied in different crops to obtain resistant genotypes to plant pathogens. We describe the development of DNA primers and probes based on the type III effector genes avrXacE1, avrXacE2, avrXacE3, avrBs2, pthA4, hpaF, and XAC3090 (leucine rich protein), and their application in the evaluation of the genetic diversity of the pathogen. A total of 49 haplotypes were identified in 157 strains by Southern blot analysis. No genetic polymorphism was detected by BOX elements - and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC-PCR) analysis, nor with the genes avrBs2, XAC3090, and hpaF. Nei's genetic diversity indexes varied from 0.65 to 0.96 for subcollections of the pathogen. One or few haplotypes were most frequent in the strain collection, but several haplotypes were represented by solely one or few strains. The PthA4 probe resulted in the higher number of haplotypes identified in the Brazilian subcollections. Greater variation in the frequency of haplotypes occurred within subcollections (93.7%) than among subcollections. Only some haplotypes were genetically distant from all others, especially those originated from Rio Grande do Sul and Santa Catarina states. These bacterial effectors are widely spread in the collections and are useful for a better understanding of the host–pathogen interaction and the search for resistance genes in host and nonhost plants.

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