Two adjacent NLR genes conferring quantitative resistance to clubroot disease in Arabidopsis are regulated by a stably inherited epiallelic variation.

Clubroot caused by the protist Plasmodiophora brassicae is a major disease affecting cultivated Brassicaceae. Using a combination of quantitative trait locus (QTL) fine mapping, CRISPR-Cas9 validation, and extensive analyses of DNA sequence and methylation patterns, we revealed that the two adjacent neighboring NLR (nucleotide-binding and leucine-rich repeat) genes AT5G47260 and AT5G47280 cooperate in controlling broad-spectrum quantitative partial resistance to the root pathogen P. brassicae in Arabidopsis and that they are epigenetically regulated.

Fructan exohydrolases (FEHs) are upregulated by salicylic acid together with defense-related genes in non-fructan accumulating plants.

The identification of several fructan exohydrolases (FEHs, EC 3.2.1.

Increased Rice Susceptibility to Rice Blast Is Related to Post-Flowering Nitrogen Assimilation Efficiency.

Reducing nitrogen leaching and nitrous oxide emissions with the goal of more sustainability in agriculture implies better identification and characterization of the different patterns in nitrogen use efficiency by crops. However, a change in the ability of varieties to use nitrogen resources could also change the access to nutrient resources for a foliar pathogen such as rice blast and lead to an increase in the susceptibility of these varieties. This study focuses on the pre- and post-floral biomass accumulation and nitrogen uptake and utilization of ten temperate japonica rice genotypes grown in controlled conditions, and the relationship of these traits with molecular markers and susceptibility to rice blast disease.

Identification and Quantification of Glucosinolates and Phenolics in a Large Panel of Highlight Valuable Genetic Resources for Chemical Ecology and Breeding.

Glucosinolate (GLS) and phenolic contents in contribute to biotic and abiotic stress responses. Breeding crop accessions harboring agroecologically relevant metabolic profiles require a characterization of the chemical diversity in germplasm. This work investigates the diversity of specialized metabolites in 281 accessions of .

Multi-Omic Investigation of Low-Nitrogen Conditional Resistance to Clubroot Reveals Genes Involved in Nitrate Assimilation.

Nitrogen fertilization has been reported to influence the development of clubroot, a root disease of species, caused by the obligate protist . Our previous works highlighted that low-nitrogen fertilization induced a strong reduction of clubroot symptoms in some oilseed rape genotypes. To further understand the underlying mechanisms, the response to infection was investigated in two genotypes "Yudal" and HD018 harboring sharply contrasted nitrogen-driven modulation of resistance toward .

Nitrogen Supply and Host-Plant Genotype Modulate the Transcriptomic Profile of .

Nitrogen fertilization can affect the susceptibility of to the telluric pathogen . Our previous works highlighted that the influence of nitrogen can strongly vary regarding plant cultivar/pathogen strain combinations, but the underlying mechanisms are unknown. The present work aims to explore how nitrogen supply can affect the molecular physiology of through its life epidemiological cycle.

Clubroot Symptoms and Resting Spore Production in a Doubled Haploid Population of Oilseed Rape () Are Controlled by Four Main QTLs.

Clubroot, caused by Woronin, is one of the most important diseases of oilseed rape ( L.). The rapid erosion of monogenic resistance in clubroot-resistant (CR) varieties underscores the need to diversify resistance sources controlling disease severity and traits related to pathogen fitness, such as resting spore production.

Resolution of quantitative resistance to clubroot into QTL-specific metabolic modules.

Plant disease resistance is often under quantitative genetic control. Thus, in a given interaction, plant cellular responses to infection are influenced by resistance or susceptibility alleles at different loci. In this study, a genetic linkage analysis was used to address the complexity of the metabolic responses of Brassica napus roots to infection by Plasmodiophora brassicae.

Quantitative resistance to clubroot infection mediated by transgenerational epigenetic variation in Arabidopsis.

Quantitative disease resistance, often influenced by environmental factors, is thought to be the result of DNA sequence variants segregating at multiple loci. However, heritable differences in DNA methylation, so-called transgenerational epigenetic variants, also could contribute to quantitative traits. Here, we tested this possibility using the well-characterized quantitative resistance of Arabidopsis to clubroot, a Brassica major disease caused by Plasmodiophora brassicae.

Nitrogen modulation of Medicago truncatula resistance to Aphanomyces euteiches depends on plant genotype.

Nitrogen (N) availability can impact plant resistance to pathogens by the regulation of plant immunity. To better understand the links between N nutrition and plant defence, we analysed the impact of N availability on Medicago truncatula resistance to the root pathogen Aphanomyces euteiches. This oomycete is considered to be the most limiting factor for legume production.

Increase of Fungal Pathogenicity and Role of Plant Glutamine in Nitrogen-Induced Susceptibility (NIS) To Rice Blast.

  Modifications in glutamine synthetase OsGS1-2 expression and fungal pathogenicity underlie nitrogen-induced susceptibility to rice blast. Understanding why nitrogen fertilization increase the impact of many plant diseases is of major importance. The interaction between and rice was used as a model for analyzing the molecular mechanisms underlying Nitrogen-Induced Susceptibility (NIS).

Hypoxia response in Arabidopsis roots infected by Plasmodiophora brassicae supports the development of clubroot.

Background: The induction of alcohol fermentation in roots is a plant adaptive response to flooding stress and oxygen deprivation. Available transcriptomic data suggest that fermentation-related genes are also frequently induced in roots infected with gall forming pathogens, but the biological significance of this induction is unclear. In this study, we addressed the role of hypoxia responses in Arabidopsis roots during infection by the clubroot agent Plasmodiophora brassicae.

Cytokinin Production by the Rice Blast Fungus Is a Pivotal Requirement for Full Virulence.

Plants produce cytokinin (CK) hormones for controlling key developmental processes like source/sink distribution, cell division or programmed cell-death. Some plant pathogens have been shown to produce CKs but the function of this mimicry production by non-tumor inducing pathogens, has yet to be established. Here we identify a gene required for CK biosynthesis, CKS1, in the rice blast fungus Magnaporthe oryzae.

Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent Plasmodiophora brassicae in Arabidopsis.

The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.

Camalexin contributes to the partial resistance of Arabidopsis thaliana to the biotrophic soilborne protist Plasmodiophora brassicae.

Camalexin has been reported to play defensive functions against several pathogens in Arabidopsis. In this study, we investigated the possible role of camalexin accumulation in two Arabidopsis genotypes with different levels of basal resistance to the compatible eH strain of the clubroot agent Plasmodiophora brassicae. Camalexin biosynthesis was induced in infected roots of both Col-0 (susceptible) and Bur-0 (partially resistant) accessions during the secondary phase of infection.

Manipulating feeding stimulation to protect crops against insect pests?

Enhancing natural mechanisms of plant defense against herbivores is one of the possible strategies to protect cultivated species against insect pests. Host plant feeding stimulation, which results from phagostimulant and phagodeterrent effects of both primary and secondary metabolites, could play a key role in levels of damage caused to crop plants. We tested this hypothesis by comparing the feeding intensity of the pollen beetle Meligethes aeneus on six oilseed rape (Brassica napus) genotypes in a feeding experiment, and by assessing the content of possible phagostimulant and phagodeterrent compounds in tissues targeted by the insect (flower buds).

Modulation of Zn/Cd P(1B2)-ATPase activities in Arabidopsis impacts differently on Zn and Cd contents in shoots and seeds.

Zn is an essential microelement for all living cells and Zn deficiency is widespread in world's population. At the same time, high Zn concentration and low Cd concentration are toxic to the environment. Both Zn and Cd are transported in planta via Zn/Cd HMA transporters.

Arabidopsis thaliana nicotianamine synthase 4 is required for proper response to iron deficiency and to cadmium exposure.

The nicotianamine synthase (NAS) enzymes catalyze the formation of nicotianamine (NA), a non-proteinogenic amino acid involved in iron homeostasis. We undertook the functional characterization of AtNAS4, the fourth member of the Arabidopsis thaliana NAS gene family. A mutant carrying a T-DNA insertion in AtNAS4 (atnas4), as well as lines overexpressing AtNAS4 both in the atnas4 and the wild-type genetic backgrounds, were used to decipher the role of AtNAS4 in NA synthesis, iron homeostasis and the plant response to iron deficiency or cadmium supply.

Partial resistance to clubroot in Arabidopsis is based on changes in the host primary metabolism and targeted cell division and expansion capacity.

To date, studies of the molecular basis of disease resistance mainly focused on qualitative resistance. However, deciphering mechanisms underlying quantitative resistance could lead to insights into the relationship between qualitative and quantitative resistance and guide the utilization of these two types of resistance to produce durably resistant cultivars. A functional genomics approach, using the CATMA whole-genome microarray, was used to detect changes in gene expression associated with partial quantitative resistance in the Arabidopsis thaliana-Plasmodiophora brassicae pathosystem.

Metabotyping: a new approach to investigate rapeseed (Brassica napus L.) genetic diversity in the metabolic response to clubroot infection.

Clubroot disease affects all Brassicaceae spp. and is caused by the obligate biotroph pathogen Plasmodiophora brassicae. The development of galls on the root system is associated with the establishment of a new carbon metabolic sink.

Arginase induction represses gall development during clubroot infection in Arabidopsis.

Arginase induction can play a defensive role through the reduction of arginine availability for phytophageous insects. Arginase activity is also induced during gall growth caused by Plasmodiophora brassicae infection in roots of Arabidopsis thaliana; however, its possible role in this context has been unclear. We report here that the mutation of the arginase-encoding gene ARGAH2 abrogates clubroot-induced arginase activity and results in enhanced gall size in infected roots, suggesting that arginase plays a defensive role.

Towards deciphering dynamic changes and evolutionary mechanisms involved in the adaptation to low salinities in Ectocarpus (brown algae).

Colonizations of freshwater by marine species are rare events, and little information is known about the underlying mechanisms. Brown algae are an independent lineage of photosynthetic and multicellular organisms from which few species inhabit freshwater. As a marine alga that is also found in freshwater, Ectocarpus is of particular interest for studying the transition between these habitats.

Genetic and physiological analysis of the relationship between partial resistance to clubroot and tolerance to trehalose in Arabidopsis thaliana.

In Arabidopsis thaliana the induction of plant trehalase during clubroot disease was proposed to act as a defense mechanism in the susceptible accession Col-0, which could thereby cope with the accumulation of pathogen-synthesized trehalose. In the present study, we assessed trehalose activity and tolerance to trehalose in the clubroot partially resistant accession Bur-0. We compared both accessions for several trehalose-related physiological traits during clubroot infection.

Integrative analysis of metabolite and transcript abundance during the short-term response to saline and oxidative stress in the brown alga Ectocarpus siliculosus.

The model brown alga Ectocarpus siliculosus undergoes extensive transcriptomic changes in response to abiotic stress, many of them related to primary metabolism and particularly to amino acid biosynthesis and degradation. In this study we seek to improve our knowledge of the mechanisms underlying the stress tolerance of this alga, in particular with regard to compatible osmolytes, by examining the effects of these changes on metabolite concentrations. We performed extensive metabolic profiling (urea, amino acids, sugars, polyols, organic acids, fatty acids) of Ectocarpus samples subjected to short-term hyposaline, hypersaline and oxidative stress, and integrated the results with previously published transcriptomic data.

Diurnal oscillations of metabolite abundances and gene analysis provide new insights into central metabolic processes of the brown alga Ectocarpus siliculosus.

• Knowledge about primary metabolic processes is essential for the understanding of the physiology and ecology of seaweeds. The Ectocarpus siliculosus genome now facilitates integrative studies of the molecular basis of primary metabolism in this brown alga. • Metabolite profiling was performed across two light-dark cycles and under different CO2 and O2 concentrations, together with genome and targeted gene expression analysis.