Goss's Wilt Resistance in Corn Is Mediated via Salicylic Acid and Programmed Cell Death but Not Jasmonic Acid Pathways.

A highly aggressive strain (CMN14-5-1) of bacteria, which causes Goss's wilt in corn, induced severe symptoms in a susceptible corn line (CO447), resulting in water-soaked lesions followed by necrosis within a few days. A tolerant line (CO450) inoculated with the same strain exhibited only mild symptoms such as chlorosis, freckling, and necrosis that did not progress after the first six days following infection. Both lesion length and disease severity were measured using the area under the disease progression curve (AUDPC), and significant differences were found between treatments.

The pangenome of the wheat pathogen Pyrenophora tritici-repentis reveals novel transposons associated with necrotrophic effectors ToxA and ToxB.

Background: In fungal plant pathogens, genome rearrangements followed by selection pressure for adaptive traits have facilitated the co-evolutionary arms race between hosts and their pathogens. Pyrenophora tritici-repentis (Ptr) has emerged recently as a foliar pathogen of wheat worldwide and its populations consist of isolates that vary in their ability to produce combinations of different necrotrophic effectors. These effectors play vital roles in disease development.

Genome-Based Analysis of Polyketide Synthase Gene Clusters.

Polyketides are structurally diverse and physiologically active secondary metabolites produced by many organisms, including fungi. The biosynthesis of polyketides from acyl-CoA thioesters is catalyzed by polyketide synthases, PKSs. Polyketides play roles including in cell protection against oxidative stress, non-constitutive (toxic) roles in cell membranes, and promoting the survival of the host organisms.

NOXA Is Important for 's Penetration Ability and Virulence.

NADPH oxidase (Nox) genes are responsible for Reactive Oxygen Species (ROS) production in living organisms such as plants, animals, and fungi, where ROS exert different functions. ROS are critical for sexual development and cellular differentiation in fungi. In previous publications, two genes encoding thioredoxin and NADH-ubiquinone oxidoreductase involved in maintaining ROS balance were shown to be remarkably induced in a highly versus a weakly aggressive isolate.

Naturally Occurring Species and Mycotoxins in Oat Grains from Manitoba, Canada.

head blight (FHB) can lead to dramatic yield losses and mycotoxin contamination in small grain cereals in Canada. To assess the extent and severity of FHB in oat, samples collected from 168 commercial oat fields in the province of Manitoba, Canada, during 2016-2018 were analyzed for the occurrence of head blight and associated mycotoxins. Through morphological and molecular analysis, was found to be the predominant species affecting oat, followed by , , , and .

Role of Exopolygalacturonase-Related Genes in Potato- Interaction.

is a hemibiotrophic pathogen responsible for great losses in dicot crop production. An gene (VDAG_03463,) identified using subtractive hybridization/cDNA-AFLP, showed higher expression levels in highly aggressive than in weakly aggressive isolates. We used a vector-free split-marker recombination method with PEG-mediated protoplast to delete the gene in This is the first instance of using this method for transformation.

Fusarium Root Rot Complex in Soybean: Molecular Characterization, Trichothecene Formation, and Cross-Pathogenicity.

Soybean is threatened by many pathogens that negatively affect this crop's yield and quality, such as various species that cause wilting and root rot diseases. Fusarium root rot (FRR) in soybean can be caused by and other spp. that are associated with Fusarium head blight (FHB) in cereals.

Gene Expression of Putative Pathogenicity-Related Genes in in Response to Elicitation with Potato Extracts and during Infection Using Quantitative Real-Time PCR.

Quantitative real-time PCR was used to monitor the expression of 15 's genes, putatively involved in pathogenicity, highly (HAV) and weakly aggressive (WAV) isolates after either (i) elicitation with potato leaf, stem, or root extracts, or (ii) inoculation of potato detached petioles. These genes, i.e.

MinION Nanopore-based detection of Clavibacter nebraskensis, the corn Goss's wilt pathogen, and bacteriomic profiling of necrotic lesions of naturally-infected leaf samples.

The Goss's bacterial wilt pathogen, Clavibacter nebraskensis, of corn is a candidate A1 quarantine organism; and its recent re-emergence and spread in the USA and Canada is a potential biothreat to the crop. We developed and tested an amplicon-based Nanopore detection system for C. nebraskensis (Cn), targeting a purine permease gene.

Secretome Analysis of Strains Treated with Natural Xylem Sap In Vitro Predicts Involvement of Glycosyl Hydrolases and Proteases in Bacterial Aggressiveness.

The Gram-positive bacterium (Cn) causes Goss's wilt and leaf blight on corn in the North American Central Plains with yield losses as high as 30%. Cn strains vary in aggressiveness on corn, with highly aggressive strains causing much more serious symptoms and damage to crops. Since Cn inhabits the host xylem, we investigated differences in the secreted proteomes of Cn strains to determine whether these could account for phenotypic differences in aggressiveness.

Overexpression of () Promotes Potato Tolerance to .

Reactive oxygen species (ROSs) represent one of the first lines of plants' biochemical defense against pathogens. Plants' respiratory burst oxidase homologs (RBOHs) produce ROSs as byproducts in several cellular compartments. In potato tubers, respiratory burst oxidase homolog (StRBOHs) are involved in suberization and healing of wounded tissues.

Polyamine-Mediated Transcriptional Regulation of Enzymatic Antioxidative Response to Excess Soil Moisture during Early Seedling Growth in Soybean.

This study examined the expression patterns of antioxidative genes and the activity of the corresponding enzymes in the excess moisture-stressed seedlings of soybean in response to seed treatment with polyamines, spermine (Spm) and spermidine (Spd). At the 4 day after planting (DAP) stage, the excess moisture impaired the embryo axis growth, and this effect is associated with the downregulation of () expression and SOD activity in the cotyledon. Seed treatment with Spm reversed the effects of excess moisture on embryo axis growth partly through enhancing glutathione reductase (GR) activity, in both the cotyledon and embryo axis, although no effect on the expression level was evident.

Specific Detection and Identification of Sensu Stricto Using a PCR-RFLP Tool and Specific Primers Targeting the Translational Elongation Factor 1α Gene.

is a toxigenic plant pathogen that causes Fusarium head blight (FHB) disease on cereal crops. It has recently shown to have cross-pathogenicity on noncereals (i.e.

Transcriptional Insight Into Resistance Genes and -Mediated Defense Response Against the Infection.

The phytopathogenic fungus causes the blackleg disease on , resulting in severe loss of rapeseed production. Breeding of resistant cultivars containing race-specific resistance genes is provably effective to combat this disease. While two allelic resistance genes and recognizing avirulence genes and at plant apoplastic space have been cloned in , the downstream gene expression network underlying the resistance remains elusive.

Transcriptome Analysis of -Mediated Host Immunity in the - Pathosystem.

Our study investigated disease resistance in the - pathosystem using a combination of laser microdissection, dual RNA sequencing, and physiological validations of large-scale gene sets. The use of laser microdissection improved pathogen detection and identified putative effectors and lytic enzymes operative during host colonization. Within 24 h of inoculation, we detected large shifts in gene activity in resistant cotyledons associated with jasmonic acid and calcium signaling pathways that accelerated the plant defense response.

Pre-treatment of soybean plants with calcium stimulates ROS responses and mitigates infection by Sclerotinia sclerotiorum.

Considering the high incidence of white mold caused by Sclerotinia sclerotiorum in a variety of field crops and vegetables, different control strategies are needed to keep the disease under economical threshold. This study assessed the effect of foliar application of a calcium formulation on disease symptoms, oxalic acid production, and on the oxidative stress metabolism in soybean plants inoculated with each of two isolates of the pathogen that have contrasting aggressiveness (HA, highly-aggressive versus WA, weakly-aggressive). Changes in reactive oxygen species (ROS) levels in soybean plants inoculated with S.

's Isochorismatase Hydrolase Is a Virulence Factor That Contributes to Interference With Potato's Salicylate and Jasmonate Defense Signaling.

This study aimed to dissect the function of the Isochorismatase Hydrolase () gene in 's pathogenesis on potato. was up-regulated in after induction with extracts from potato tissues. Its expression increased more in response to root extracts than to leaf and stem extracts.

Analyses of genetic diversity of bacterial blight pathogen, Xanthomonas oryzae pv. oryzae using IS1112 in Bangladesh.

Bacterial blight (BB) is caused by Xanthomonas oryzae pv. oryzae (Xoo), a most destructive disease of rice, mostly in Asia, including Bangladesh. Altogether 96 isolates of Xoo were collected from 19 rice-growing districts of Bangladesh in both the rain-fed and irrigated seasons of 2014 to assess their pathotypic and genetic variation.

Genome Analysis and Development of a Multiplex TaqMan Real-Time PCR for Specific Identification and Detection of Clavibacter michiganensis subsp. nebraskensis.

The reemergence of the Goss's bacterial wilt and blight disease in corn in the United States and Canada has prompted investigative research to better understand the genome organization. In this study, we generated a draft genome sequence of Clavibacter michiganensis subsp. nebraskensis strain DOAB 395 and performed genome and proteome analysis of C.

Molecular cloning, functional characterization and expression of potato (Solanum tuberosum) 1-deoxy-d-xylulose 5-phosphate synthase 1 (StDXS1) in response to Phytophthora infestans.

1-Deoxy-D-xylulose 5-phosphate synthase (DXS) catalyzes the initial step of the plastidial 2C-methyl-D-erythritol-4-phosphate (DOXP-MEP) pathway involved in isoprenoid biosynthesis. In this study, we cloned the complete cDNA of potato DXS gene that was designated StDXS1. StDXS1 cDNA encodes for 719 amino acid residues, with MW of 77.

Draft Genome Sequence of Clavibacter michiganensis subsp. nebraskensis Strain DOAB 397, Isolated from an Infected Field Corn Plant in Manitoba, Canada.

In 2014, the pathogen Clavibacter michiganensis subsp. nebraskensis was isolated from symptomatic corn leaves in Manitoba, Canada. We report the draft genome sequence of C.

A cupin domain-containing protein with a quercetinase activity (VdQase) regulates Verticillium dahliae's pathogenicity and contributes to counteracting host defenses.

We previously identified rutin as part of potato root responses to its pathogen Verticillium dahliae. Rutin was directly toxic to the pathogen at doses greater than 160 μM, a threshold below which many V. dahliae pathogenicity-related genes were up-regulated.

The Top 10 oomycete pathogens in molecular plant pathology.

Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens which threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant-pathogenic oomycete species based on scientific and economic importance. In total, we received 263 votes from 62 scientists in 15 countries for a total of 33 species.

Biochemical and molecular characterization of barley plastidial ADP-glucose transporter (HvBT1).

In cereals, ADP-glucose transporter protein plays an important role in starch biosynthesis. It acts as a main gate for the transport of ADP-glucose, the main precursor for starch biosynthesis during grain filling, from the cytosol into the amyloplasts of endospermic cells. In this study, we have shed some light on the molecular and biochemical characteristics of barley plastidial ADP-glucose transporter, HvBT1.