The Practical Role of Induced Resistance for Crop Protection.

Plants have evolved a highly sophisticated immune system to resist pathogen attack comprising both preformed and inducible mechanisms. Over the last 50 years, various biological and chemical inducers have been used to artificially trigger the defense response in plants, thereby promoting an induced resistance (IR) to subsequent pathogen attack. IR has proven effective for disease control in laboratory and glasshouse conditions but has seldom equalled the level of protection offered by synthetic pesticides in the field.

Deciphering Molecular Host-Pathogen Interactions During Infection on Barley.

is the causal agent of Ramularia leaf spot disease (RLS) on barley and became, during the recent decades, an increasing threat for farmers across the world. Here, we analyze morphological, transcriptional, and metabolic responses of two barley cultivars having contrasting tolerance to RLS, when infected by an aggressive or mild isolate. We found that fungal biomass in leaves of the two cultivars does not correlate with their tolerance to RLS, and both cultivars displayed cell wall reinforcement at the point of contact with the fungal hyphae.

Dissection of Ramularia Leaf Spot Disease by Integrated Analysis of Barley and Ramularia collo-cygni Transcriptome Responses.

Ramularia leaf spot disease (RLS), caused by the ascomycete fungus Ramularia collo-cygni, has emerged as a major economic disease of barley. No substantial resistance has been identified, so far, among barley genotypes and, based on the epidemiology of the disease, a quantitative genetic determinacy of RLS has been suggested. The relative contributions of barley and R.

The genome of the emerging barley pathogen Ramularia collo-cygni.

Background: Ramularia collo-cygni is a newly important, foliar fungal pathogen of barley that causes the disease Ramularia leaf spot. The fungus exhibits a prolonged endophytic growth stage before switching life habit to become an aggressive, necrotrophic pathogen that causes significant losses to green leaf area and hence grain yield and quality.

Results: The R.

Diagnosis of Ramularia collo-cygni and Rhynchosporium spp. in Barley.

Ramularia leaf spot and Rhynchosporium leaf scald are two of the major diseases of barley crops in cooler temperate countries. The methods below are aimed at the identification and quantification of fungal DNA in leaf samples but can also be used for pathogen detection from seed or DNA extracted from environmental samplers. The methods describe in detail two individual quantitative PCR tests.

Ramularia collo-cygni--An Emerging Pathogen of Barley Crops.

Ramularia collo-cygni is the biotic factor responsible for the disease Ramularia leaf spot (RLS) of barley (Hordeum vulgare). Despite having been described over 100 years ago and being considered a minor disease in some countries, the fungus is attracting interest in the scientific community as a result of the increasing number of recorded economically damaging disease epidemics. New reports of disease spread and fungal identification using molecular diagnostics have helped redefine RLS as a global disease.

Control of foliar pathogens of spring barley using a combination of resistance elicitors.

The ability of the resistance elicitors acibenzolar-S-methyl (ASM), β-aminobutyric acid (BABA), cis-jasmone (CJ), and a combination of the three products, to control infection of spring barley by Rhynchosporium commune was examined under glasshouse conditions. Significant control of R. commune was provided by ASM and CJ, but the largest reduction in infection was obtained with the combination of the three elicitors.

First Molecular Detection of Ramularia Leaf Spot (Ramularia collo-cygni) in Seeds and Leaves of Barley in Argentina.

The fungus Ramularia collo-cygni B. Sutton & J. M.

Disease risk curves.

Disease risk curves are simple graphical relationships between the probability of need for treatment and evidence related to risk factors. In the context of the present article, our focus is on factors related to the occurrence of disease in crops. Risk is the probability of adverse consequences; specifically in the present context it denotes the chance that disease will reach a threshold level at which crop protection measures can be justified.

Controlling crop diseases using induced resistance: challenges for the future.

A number of different types of induced resistance have been defined based on differences in signalling pathways and spectra of effectiveness, including systemic acquired resistance and induced systemic resistance. Such resistance can be induced in plants by application of a variety of biotic and abiotic agents. The resulting resistance tends to be broad-spectrum and can be long-lasting, but is rarely complete, with most inducing agents reducing disease by between 20 and 85%.

Cultivar Effects on the Expression of Induced Resistance in Spring Barley.

The influence of host genotype on the expression of induced resistance was examined in several cultivars of spring barley (Hordeum vulgare). Induced resistance was activated using a combination of elicitors (acibenzolar- S-methyl, β-aminobutyric acid, and cis-jasmone) shown in previous work to induce resistance effectively in barley. The barley cultivars examined were Cellar, Chalice, Decanter, Oxbridge, Tipple, Troon, and Westminster, which differed in their genetic resistance to two major pathogens of barley, Rhynchosporium secalis and Blumeria graminis f.

A quantitative real-time PCR assay for the detection of Ramularia collo-cygni from barley (Hordeum vulgare).

Aims: The aim of this study was to develop a real-time quantitative PCR test to recognize and quantify the DNA levels of the increasingly important barley pathogen Ramularia collo-cygni.

Methods And Results: The method described uses specifically designed primers and a molecular beacon probe based on an internal transcribed spacer (ITS) sequence. Pathogen extracted from barley leaves could be quantified to the picogram level in both leaves showing symptoms of infection and symptomless barley leaves.

Ramularia collo-cygni: the biology of an emerging pathogen of barley.

Ramularia collo-cygni is now recognized as an important pathogen of barley in Northern Europe and New Zealand. It induces necrotic spotting and premature leaf senescence, leading to loss of green leaf area in crops, and can result in substantial yield losses. The fungus produces a number of anthraquinone toxins called rubellins, which act as host nonspecific toxins with photodynamic activity.

Rapid nested PCR-based detection of Ramularia collo-cygni direct from barley.

Ramularia collo-cygni is a barley pathogen of increasing importance in Northern and Central Europe, New Zealand and South America. Accurate visual and microscopic identification of the pathogen from diseased tissue is difficult. A nested PCR-based diagnostic test has been developed as part of an initiative to map the distribution of the pathogen in Scotland.

Synthesis and antifungal activity of two novel spermidine analogues.

Two spermidine analogues were synthesised and examined for antifungal activity. Both compounds used as 1 mM post-inoculation sprays reduced infection of barley seedlings by the powdery mildew fungus, Erysiphe graminis f.sp.