scholarly journals The Epichloë festucae Antifungal Protein Efe-AfpA Is Also a Possible Effector Protein Required for the Interaction of the Fungus with its Host Grass Festuca rubra subsp. rubra

2021 ◽  
Vol 9 (1) ◽  
pp. 140
Author(s):  
Ruying Wang ◽  
Simin Luo ◽  
Bruce B. Clarke ◽  
Faith C. Belanger
Keyword(s):  
Disease Resistance ◽  
Insect Resistance ◽  
Effector Proteins ◽  
Antifungal Protein ◽  
Grass Species ◽  
Effector Protein ◽  
Festuca Rubra ◽  
Symbiotic Interaction ◽  
Red Fescue ◽  
Epichloë Festucae

Strong creeping red fescue (Festuca rubra subsp. rubra) is a commercially important low-maintenance turfgrass and is often naturally infected with the fungal endophyte Epichloë festucae. Epichloë spp. are endophytes of several cool-season grass species, often conferring insect resistance to the grass hosts due to the production of toxic alkaloids. In addition to insect resistance, a unique feature of the strong creeping red fescue/E. festucae symbiosis is the endophyte-mediated disease resistance to the fungal pathogen Clarireedia jacksonii, the causal agent of dollar spot disease. Such disease resistance is not a general feature of other grass/ Epichloë interactions. E. festucae isolates infecting red fescue have an antifungal protein gene Efe-afpA, whereas most other Epichloë spp. do not have a similar gene. The uniqueness of this gene suggests it may, therefore, be a component of the unique disease resistance seen in endophyte-infected red fescue. Here, we report the generation of CRISPR-Cas9 Efe-afpA gene knockouts with the goal of determining if absence of the protein in endophyte-infected Festuca rubra leads to disease susceptibility. However, it was not possible to infect plants with the knockout isolates, although infection was possible with the wild type E. festucae and with complemented isolates. This raises the interesting possibility that, in addition to having antifungal activity, the protein is required for the symbiotic interaction. The antifungal protein is a small secreted protein with high expression in planta relative to its expression in culture, all characteristics consistent with effector proteins. If Efe-AfpA is an effector protein it must be specific to certain interactions, since most Epichloë spp. do not have such a gene in their genomes.

scholarly journals Transcriptome Analysis of Choke Stroma and Asymptomatic Inflorescence Tissues Reveals Changes in Gene Expression in Both Epichloë festucae and Its Host Plant Festuca rubra subsp. rubra

2019 ◽  
Vol 7 (11) ◽  
pp. 567
Author(s):  
Wang ◽  
Clarke ◽  
Belanger
Keyword(s):  
Gene Expression ◽  
Fungal Endophytes ◽  
Plant Stress ◽  
Effector Proteins ◽  
Differentially Expressed ◽  
Festuca Rubra ◽  
Plant Host ◽  
Red Fescue ◽  
Epichloë Festucae ◽  
Fungal Genes

Many cool-season grasses have symbiotic relationships with Epichloë (Ascomycota, Clavicipitaceae) fungal endophytes that inhabit the intercellular spaces of the above-ground parts of the host plants. The presence of the Epichloë endophytes is generally beneficial to the hosts due to enhanced tolerance to biotic and abiotic stresses conferred by the endophytes. Many Epichloë spp. are asexual, and those infections always remain asymptomatic. However, some Epichloë spp. have a sexual stage and produce a macroscopic fruiting body, a stroma, that envelops the developing inflorescence causing a syndrome termed “choke disease”. Here, we report a fungal and plant gene expression analysis of choke stroma tissue and asymptomatic inflorescence tissue of Epichloë festucae-infected strong creeping red fescue (Festuca rubra subsp. rubra). Hundreds of fungal genes and over 10% of the plant genes were differentially expressed when comparing the two tissue types. The differentially expressed fungal genes in the choke stroma tissue indicated a change in carbohydrate and lipid metabolism, as well as a change in expression of numerous genes for candidate effector proteins. Plant stress-related genes were up-regulated in the stroma tissue, suggesting the plant host was responding to the epiphytic stage of E. festucae as a pathogen.

scholarly journals The breeding of 'Grasslands Muster' browntop and other low-fertility grasses for moist hill country

1990 ◽  
pp. 143-146
Author(s):  
W. Rumball ◽  
R.B. Claydon
Keyword(s):  
Grazing Pressure ◽  
Low Fertility ◽  
Grass Species ◽  
Festuca Rubra ◽  
Holcus Lanatus ◽  
Hill Country ◽  
Red Fescue ◽  
Lower Fertility ◽  
Mowing Regime ◽  
Clover Content

Breeding projects have been carried out in each of five grass species already common in New Zealand moist hill country. Although the source of breeding material varied widely among the five species, the breeding goals in each were for improved amount and seasonal spread of productivity, persistence, disease resistance, palatability, uniform heading, and tolerance of white clover. The projects began around 1973 and were all completed by 1980. From 198 I-85, the selections were evaluated in small plots on sunny and shady slopes of hill country near Palmerston North. In all species except Yorkshire fog, the selections outyielded their respective commercial controls in the first l-2 years. In the two browntop species (Agrostis capillaris and A. castellana) this superiority continued through the trial, despite selective grazing pressure. In Yorkshire fog (Holcus lanatus) and red fescue (Festuca rubra) the selections were more palatable but not as persistent as their controls after 5 years. In crested dogstail (Cynosurus cristatus) neither selection nor control persisted, and the mowing regime applied did not allow natural reseeding. In a further trial on lowland, all five selections except dryland browntop were confirmed as considerably more palatable than the controls, and most had more clover content. The best strategy would probably be to market these selections as a hill country/lower fertility seed package (with suitable clovers), so as to exclude less palatable components. Keywords hill country, breeding, browntop, Yorkshire fog, crested dogstail, red fescue, low fertility grasses

Phytophagous arthropods and silvertop levels associated with post-harvest residue treatments in three turfgrass species grown for seed

2005 ◽  
Vol 85 (1) ◽  
pp. 213-224 ◽  
Author(s):  
J. J. Soroka ◽  
B. D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Residue Management ◽  
Grass Species ◽  
Festuca Rubra ◽  
Agrostis Palustris ◽  
Red Fescue ◽  
The Impact

Silvertop, which is characterized by whitish, completely sterile seed heads produced on green tillers, is a common symptom in many perennial grasses. A 3-yr study of creeping bentgrass (Agrostis palustris), Kentucky bluegrass (Poa pratensis) and creeping red fescue (Festuca rubra subsp. rubra) grown for seed production was conducted at Saskatoon, Saskatchewan, to investigate the cause(s) of silvertop, the impact of residue management strategies on silvertop incidence, and the impact of silvertop on seed yield. Three residue management practices were applied in the fall of the first harvest year and again the next fall, as follows: (i) burned after harvest; (ii) clipped to 1–2 cm in height and the residue removed; or (iii) mowed to 20 cm and the residue retained. Arthropods in each plot were collected weekly from May until July by sweep sampling, counted, and identified to family level or lower, and the incidence of seed heads with and without silvertop were assessed. The majority of arthropods were thrips, leafhoppers, plant bugs, mites, or grass-dwelling flies. Grass species and residue treatment strongly affected the number of reproductive tillers and levels of silvertop. Levels of silvertop were lowest in creeping bentgrass in all 3 yr of the study, while they were similar for Kentucky bluegrass and creeping red fescue. Mown plots had fewer reproductive tillers, fewer heathy seed heads, and higher levels of silvertop than burned or clipped plots. However, arthropod species composition was generally similar across grass species and residue treatments. This indicates that a specific arthropod taxon may not be a critical factor in silvertop expression. The relationship between the number and composition of arthropods found and incidence of silvertop is discussed. Key words: Festuca rubra subsp. rubra, Poa pratensis, Agrostis palustris, seed production, arthropods, silvertop

Germination of Seeds of Turfgrasses as Affected by Glyphosate and Paraquat

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 191-193 ◽  
Author(s):  
Dayton L. Klingman ◽  
J. J. Murray
Keyword(s):  
Seed Germination ◽  
Tall Fescue ◽  
Poa Pratensis ◽  
Soil Surface ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Festuca Rubra ◽  
Red Fescue ◽  
Grass Turf

Effects of glyphosate [N-(phosphonomethyl)glycine] and paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) on turfgrass seed germination were evaluated in the greenhouse. Glyphosate caused little effect on germination of Kentucky bluegrass (Poa pratensis L.), red fescue (Festuca rubra L.), and tall fescue (F. arundinacea Schreb.) when applied to the soil immediately before seeding or when applied directly over the seed on the soil surface. Paraquat sprayed directly over the seed on the soil surface prevented germination of most of the seeds of the three grass species. Covering seeds on the soil surface with clippings from grass turf sprayed with paraquat greatly reduced germination. About half of those that germinated either died later or were severely chlorotic. Covering seeds on the surface of the soil with clippings from turf that had been sprayed with glyphosate did not significantly reduce the number of seedlings established.

scholarly journals Analysis of Epichloë festucae small secreted proteins in the interaction with Lolium perenne

2018 ◽  
Author(s):  
Barry Scott ◽  
Berit Hassing ◽  
David Winter ◽  
Carl Mesarich ◽  
Carla Eaton ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Vital Role ◽  
Effector Proteins ◽  
Secreted Proteins ◽  
In Planta ◽  
Dynamic Features ◽  
Symbiotic Interaction ◽  
Extracellular Medium ◽  
Epichloë Festucae ◽  
Small Secreted Proteins

Epichloë festucae is an endophyte of the agriculturally important perennial ryegrass. This species systemically colonises the aerial tissues of this host where its growth is tightly regulated thereby maintaining a mutualistic symbiotic interaction. Recent studies have suggested that small secreted proteins, termed effectors, play a vital role in the suppression of host defence responses. To date only a few effectors with important roles in mutualistic interactions have been described. Here we make use of the fully assembled E. festucae genome and EffectorP to generate a suite of 141 effector candidates. These were analysed with respect to their genome location and expression profiles in planta and in several symbiosis-defective mutants. We found an association between effector candidates and a class of transposable elements known as MITEs, but no correlation with other dynamic features of the E. festucae genome, such as transposable element-rich regions. Three effector candidates and a small GPI-anchored protein were chosen for functional analysis based on their high expression in planta compared to in culture and their differential regulation in symbiosis defective E. festucae mutants. All three candidate effector proteins were shown to possess a functional signal peptide and two could be detected in the extracellular medium by western blotting. Localization of the effector candidates in planta suggests that they are not translocated into the plant cell, but rather, are localized in the apoplastic space or are attached to the cell wall. Deletion and overexpression of the effector candidates, as well as the putative GPI-anchored protein, did not affect the plant growth phenotype or restrict growth of E. festucae mutants in planta. These results indicate that these proteins are either not required for the interaction at the observed life stages or that there is redundancy between effectors expressed by E. festucae.

UPTAKE OF RADIOISOTOPES BY VEGETATION GROWING ON URANIUM TAILINGS

1977 ◽  
Vol 57 (4) ◽  
pp. 417-424 ◽  
Author(s):  
D. MOFFETT ◽  
M. TELLIER
Keyword(s):  
Plant Tissue ◽  
Phalaris Arundinacea ◽  
Grass Species ◽  
Festuca Rubra ◽  
Reed Canary Grass ◽  
Red Fescue ◽  
Canary Grass ◽  
Lead 210 ◽  
Uranium Tailings ◽  
Field Plots

An investigation was carried out on the uptake of several long-lived radioisotopes by grasses growing on uranium tailings. Field plots of creeping red fescue (Festuca rubra L.), reed canary grass (Phalaris arundinacea L.), redtop (Agrostis alba L.) and climax timothy (Phleum pratensis L.) which have been growing for 4 yr were sampled in this study. The tailings and the plant tissue were analyzed for uranium, thorium, radium-226, lead-210 and polonium-210. Sedimentation within the tailings area gave two zones: one of sands and one of slimes. The slimes contained significantly more radium-226, lead-210 and polonium-210 than the sands. There was no difference in uptake behavior by grasses growing in the sands and those growing in the slimes. Creeping red fescue (Festuca rubra L.) showed an anomalous uptake of lead-210, but other than this, all four grass species showed similar uptake behavior. Only uranium and radium-226 were significantly higher in the grasses from the tailings than the control.

COPPER, MOLYBDENUM AND SULFUR CONTENTS OF FORAGE CROPS AT KAPUSKASING, ONTARIO

1970 ◽  
Vol 50 (6) ◽  
pp. 685-691 ◽  
Author(s):  
J. R. LESSARD ◽  
M. HIDIROGLOU ◽  
R. B. CARSON ◽  
J. M. WAUTHY
Keyword(s):  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Birdsfoot Trefoil ◽  
Festuca Rubra ◽  
Forage Crops ◽  
Reed Canarygrass ◽  
Red Fescue ◽  
Cu Content ◽  
Dactylis Glomerata L ◽  
Phleum Pratense L

Each of the species birdsfoot trefoil (Lotus corniculatus L.), timothy (Phleum pratense L.), bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.) and creeping red fescue (Festuca rubra L.) was grown in the field on 10 plots sampled at weekly intervals in rotation from June 13. Each plot was resampled after 6 weeks and all samples were analyzed for copper, molybdenum and sulfur. In most species, levels of Cu and Mo were highest in the early samplings and decreased with advancing maturity. Second-cut samples tended to be higher in Cu, Mo and S than first-cut samples. The S content was more uniform in the first cycle but increased considerably in the second cycle, especially in reed canarygrass. The ranges in Cu content were 7.4 to 14.1 ppm for birdsfoot trefoil and 3.7 to 11.4 ppm for the grasses. Mo ranged from 1.9 to 8.1 ppm in birdsfoot trefoil and from 1.0 to 6.5 ppm in the grasses. The overall range in S content was from 0.14 to 0.95%. The mineral composition of the crops is discussed in relation to the requirement of ruminants for these three elements.

Effect of method and time of application of nitrogen fertiliser on yield and quality of seed of creeping red fescue

2000 ◽  
Vol 80 (4) ◽  
pp. 809-811 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Quality ◽  
Early Spring ◽  
Festuca Rubra ◽  
Grass Seed ◽  
Red Fescue ◽  
Time Of Application ◽  
Vigorous Plant ◽  
Tiller Density

Six trials were conducted on commercial seed fields of creeping red fescue (Festuca rubra L. var. rubra) in the Peace region to evaluate the sensitivity of seed production to the method and time of application of N fertiliser. In each trial, 68 kg ha−1 N was applied using three methods (surface-broadcast, granular, ammonium nitrate 34-0-0; foliar/soil spray of 28-0-0 solution N; soil-injected 28-0-0 solution N) at each of three times (fall, early spring, late spring). No statistically significant (P = 0.05) interaction, or main effect, of method and time of N were revealed for seed yield, fertile tiller density or for several seed quality characteristics. Seed yield varied greatly among trials (142 to 1240 kg ha−1) and averaged 566 kg ha−1. The results indicate that there is considerable flexibility in the method and time of application of N fertiliser for seed production of creeping red fescue in the Peace region, provided it is applied before the commencement of vigorous plant growth in the spring. Key words: Creeping red fescue, Festuca rubra L., nitrogen fertility, grass seed production, grass seed quality

The effect of species complexity and sodium fertilizer application on the grazing behaviour of calves

1993 ◽  
Vol 1993 ◽  
pp. 142-142
Author(s):  
M. Youssef ◽  
P.C. Chiy ◽  
C.J.C. Phillips ◽  
M. Metwally
Keyword(s):  
Perennial Ryegrass ◽  
Fertilizer Application ◽  
Grass Species ◽  
Individual Plant ◽  
Adult Cattle ◽  
High Sodium ◽  
Red Fescue ◽  
Stages Of Growth ◽  
High Sodium Diet ◽  
Grazing Behaviour

Cattle exhibit preferences not only for certain sward species but for the same species at different stages of growth, and the various parts of an individual plant and for individual plant of preferred composition. This tendency is termed selective grazing (Fontenot and Blaser, 1965). For example ruminants will select a high Sodium diet. Calves tend to be more selective than adult cattle, muzzling herbage before eating.The aim of the present experiment was to investigate the effect of sward complexity, species and sodium fertilizer on the grazing behaviour of calves.Sixteen dairy Friesian calves, aged 5 to 6 months, with no previous grazing experience, were allocated to groups of 4 similar calves, and then at random to four pasture treatments of 3480m2 each with one (Perennial Ryegrass, P), two (P and Timothy, T), three (P, T and Cocksfoot, C) and four (P, T.C and Red Fescue, R) grass species in a balanced change over design. Each species was sown in plots of 290m2 and one half of each plot received 48Kg/ha. nacl.

scholarly journals Peptidomimetic Small Molecules Disrupt Type IV Secretion System Activity in Diverse Bacterial Pathogens

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Carrie L. Shaffer ◽  
James A. D. Good ◽  
Santosh Kumar ◽  
K. Syam Krishnan ◽  
Jennifer A. Gaddy ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Small Molecules ◽  
Bacterial Pathogens ◽  
Effector Proteins ◽  
Type Iv Secretion ◽  
Target Cells ◽  
Effector Protein ◽  
Secretion Systems ◽  
Type Iv ◽  
H Pylori

ABSTRACT Bacteria utilize complex type IV secretion systems (T4SSs) to translocate diverse effector proteins or DNA into target cells. Despite the importance of T4SSs in bacterial pathogenesis, the mechanism by which these translocation machineries deliver cargo across the bacterial envelope remains poorly understood, and very few studies have investigated the use of synthetic molecules to disrupt T4SS-mediated transport. Here, we describe two synthetic small molecules (C10 and KSK85) that disrupt T4SS-dependent processes in multiple bacterial pathogens. Helicobacter pylori exploits a pilus appendage associated with the cag T4SS to inject an oncogenic effector protein (CagA) and peptidoglycan into gastric epithelial cells. In H. pylori , KSK85 impedes biogenesis of the pilus appendage associated with the cag T4SS, while C10 disrupts cag T4SS activity without perturbing pilus assembly. In addition to the effects in H. pylori , we demonstrate that these compounds disrupt interbacterial DNA transfer by conjugative T4SSs in Escherichia coli and impede vir T4SS-mediated DNA delivery by Agrobacterium tumefaciens in a plant model of infection. Of note, C10 effectively disarmed dissemination of a derepressed IncF plasmid into a recipient bacterial population, thus demonstrating the potential of these compounds in mitigating the spread of antibiotic resistance determinants driven by conjugation. To our knowledge, this study is the first report of synthetic small molecules that impair delivery of both effector protein and DNA cargos by diverse T4SSs. IMPORTANCE Many human and plant pathogens utilize complex nanomachines called type IV secretion systems (T4SSs) to transport proteins and DNA to target cells. In addition to delivery of harmful effector proteins into target cells, T4SSs can disseminate genetic determinants that confer antibiotic resistance among bacterial populations. In this study, we sought to identify compounds that disrupt T4SS-mediated processes. Using the human gastric pathogen H. pylori as a model system, we identified and characterized two small molecules that prevent transfer of an oncogenic effector protein to host cells. We discovered that these small molecules also prevented the spread of antibiotic resistance plasmids in E. coli populations and diminished the transfer of tumor-inducing DNA from the plant pathogen A. tumefaciens to target cells. Thus, these compounds are versatile molecular tools that can be used to study and disarm these important bacterial machines.

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