Diverse communities of bacteria inhabit plant leaves and roots those play a crucial role for health growth. Arabidopsis thaliana is an important model to study pathogen interactions, but little known about its associated bacterial community under natural conditions. We used 454 pyrosequencing characterize the with wild A. collected at 4 sites; we further compared on outside plants in endophytic compartments. found that most heavily sequenced are related culturable species. Proteobacteria,...

Abstract Transcript patterns elicited in response to attack reveal, at the molecular level, how plants respond aggressors. These are fashioned both by inflicted physical damage as well biological components displayed or released attacker. Different types of attacking organisms might therefore be expected elicit different transcription programs host. Using a large-scale DNA microarray, we characterized gene expression damaged distal Arabidopsis thaliana leaves specialist insect, Pieris rapae....

The identity of plant host genetic factors controlling the composition microbiota and extent to which genes affect associated microbial populations is currently unknown. Here, we use a candidate gene approach investigate effects on phyllosphere community abundance. To reduce environmental that might mask factors, model Arabidopsis thaliana was used in gnotobiotic system inoculated with reduced complexity synthetic bacterial composed seven strains representing most abundant phyla...

Alternative solutions to mineral fertilizers and pesticides that reduce the environmental impact of agriculture are urgently needed. Arbuscular mycorrhizal fungi (AMF) can enhance plant nutrient uptake stress; yet, large-scale field inoculation trials with AMF missing, so far, results remain unpredictable. We conducted on-farm experiments in 54 fields Switzerland quantified effects on maize growth. Growth response was highly variable, ranging from -12% +40%. With few soil parameters mainly...

Insect attack triggers changes in transcript level plants that are mediated predominantly by jasmonic acid (JA). The implication of ethylene (ET), salicylic (SA), and other signals this response is less understood was monitored with a microarray containing insect- defense-regulated genes. Arabidopsis thaliana mutants coi1-1, ein2-1, sid2-1 impaired JA, ET, SA signaling pathways were challenged the specialist small cabbage white (Pieris rapae) generalist Egyptian cotton worm (Spodoptera...

Rhizobacteria-induced systemic resistance (ISR) and pathogen-induced acquired (SAR) have a broad, yet partly distinct, range of effectiveness against pathogenic microorganisms. Here, we investigated the ISR SAR in Arabidopsis tissue-chewing insects Pieris rapae Spodoptera exigua. Resistance consists direct defense, such as production toxins feeding deterrents indirect defense plant volatiles that attract carnivorous enemies herbivores. Wind-tunnel experiments revealed did not affect...

ABSTRACT Real-time quantitative PCR (qPCR) is a widely used technique in microbial community analysis, allowing the quantification of number target genes sample. Currently, standard-curve (SC) method absolute employed for these kinds analysis. However, SC assumes that amplification efficiency ( E ) same both standard and sample template. We analyzed 19 bacterial strains nine environmental samples qPCR assays, targeting nifH 16S rRNA genes. The values qPCRs differed significantly, depending...

Summary Plants often respond to pathogen or insect attack by inducing the synthesis of toxic compounds such as phytoalexins and glucosinolates (GS). The Arabidopsis mutant pad2‐1 has reduced levels phytoalexin camalexin is known for its increased susceptibility fungal bacterial pathogens. We found that also more susceptible generalist Spodoptera littoralis but not specialist Pieris brassicae . PAD2 gene encodes a γ‐glutamylcysteine synthetase involved in glutathione (GSH) synthesis,...

Summary Plants are colonized by a variety of bacteria, most which not pathogenic. Currently, the plant responses to phyllosphere commensals or pathogen infection in presence well understood. Here, we examined transcriptional response Arabidopsis thaliana leaves colonization common commensal bacteria gnotobiotic system using RNA sequencing and conducted mutant assays. responded differently model Sphingomonas melonis Fr1 (S.Fr1) Methylobacterium extorquens PA 1 (M. 1). Whereas M. only...

The induction of plant defences and their subsequent suppression by insects is thought to be an important factor in the evolutionary arms race between plants herbivores. Although insect oral secretions (OS) contain elicitors that trigger immunity, little known about suppressors defences. Arabidopsis thaliana transcriptome was analysed response wounding OS treatment. expression several wound-inducible genes suppressed after application from two lepidopteran herbivores, Pieris brassicae...

Summary Bacteria belonging to the genus B urkholderia are highly versatile with respect their ecological niches and lifestyles, ranging from nodulating tropical plants causing melioidosis fatal infections in cystic fibrosis patients. Despite clinical importance agronomical relevance of species, information about factors influencing occurrence, abundance diversity environment is scarce. Recent findings have demonstrated that pH main predictor soil bacterial community structure, highest...

Maintaining soil quality for agricultural production is a critical challenge, especially in the tropics. Due to focus on environmental performance and provision of ecosystem services, organic farming agroforestry systems are proposed as alternative options conventional monoculture farming. Soil processes underlying services strongly mediated by microbes; thus, increased understanding microbiome crucial development sustainable practices. Therefore, we measured related indicators bacterial...

In response to insect herbivory, Arabidopsis plants activate the synthesis of phytohormone jasmonate-isoleucine (JA-Ile), which binds a complex consisting receptor COI1 and JAZ repressors. Upon proteasome-mediated degradation, basic helix-loop-helix transcription factors (TFs) MYC2, MYC3, MYC4 become activated this results in expression defence genes. Although jasmonate (JA) pathway is known be essential for massive transcriptional reprogramming that follows there however little information...

Abstract Although slugs and snails play important roles in terrestrial ecosystems cause considerable damage on a variety of crop plants, knowledge about the mechanisms plant immunity to molluscs is limited. We found be natural herbivores Arabidopsis thaliana therefore investigated possible resistance this species against several molluscan herbivores. Treating wounded leaves with mucus residue (‘slime trail’) Spanish slug Arion lusitanicus increased wound‐induced jasmonate levels, suggesting...

Abstract Soil nematode communities and food web indices can inform about the complexity, nutrient flows decomposition pathways of soil webs, reflecting quality. Relative abundance feeding life‐history groups are used for calculating indices, i.e., maturity index (MI), enrichment (EI), structure (SI) channel (CI). Molecular methods to study potentially offer advantages compared traditional in terms resolution, throughput, cost time. In spite such advantages, molecular data have not often been...

Abstract Background A major aim in plant microbiome research is determining the drivers of plant-associated microbial communities. While soil characteristics and host identity present key root composition, it still unresolved whether presence or absence important symbionts also determines overall composition. Arbuscular mycorrhizal fungi (AMF) N-fixing rhizobia bacteria are widespread, beneficial that significantly enhance nutrition, health, structure. Thus, we hypothesized symbiont types...

Drought and agricultural management influence soil microorganisms with unknown consequences for the functioning of agroecosystems. We simulated drought periods in organic (biodynamic) conventional wheat fields monitored effects on water content, crops. Above wilting point, content microbial respiration were higher under biodynamic than farming. Highest bacterial fungal abundances found biodynamically managed soils, distinct communities characterised farming systems. Most biological quality...

Plants are constantly challenged by pathogens, which can cause substantial yield losses. The aggressiveness of and damage pathogens depends on the host-associated microbiome, might be shaped plant genetics to improve resistance. How different crop genotypes modulate their microbiota when a complex is largely unknown. Here, we investigate if how pea ( Pisum sativum L.) shape root upon challenge soil-borne this relates genotype's Building phenotyping efforts 252 grown in naturally infested...

Abstract As the human population grows, so does demand for higher agricultural yields. a result, intensification practices are increasing while soil health is often declining. Integrating benefits of microorganisms into management systems can reduce need external resource inputs. One particular group plant symbionts that help plants to acquire additional nutrients and promote growth arbuscular mycorrhizal fungi (AMF). The application AMF in practice has been hampered by variability success...

Late blight, caused by the oomycete Phytophthora infestans, is most devastating disease of potato. In organic farming, late blight controlled repeated applications copper-based products, which negatively impact environment. To find alternative solutions for management, we have previously isolated a large collection bacteria from phyllosphere and rhizosphere potatoes. Here report antagonistic potential these strains when co-cultivated with P. infestans as well other potato pathogens. We then...

Phosphorus (P) is a limiting element for plant growth. Several root microbes, including arbuscular mycorrhizal fungi (AMF), have the capacity to improve nutrition and their abundance known depend on P fertility. However, how complex root-associated bacterial fungal communities respond various levels of supplementation remains ill-defined. Here we investigated responses bacteria varying supply using 16S rRNA gene internal transcribed spacer amplicon sequencing. We grew Petunia, which forms...

Abstract Introduction Biogeography describes spatial patterns of diversity and explains why organisms occur in given conditions. While it is well established that the soil microbes largely controlled by edaphic environmental variables, microbiome community prediction from properties has received less attention. In this study, we specifically investigated whether possible to predict composition fungal communities based on physicochemical data using multivariate ordination. Materials Methods...

Abstract Arbuscular mycorrhiza fungi (AMF) are beneficial soil that can promote the growth of their host plants. Accurate quantification AMF in plant roots is important because level colonization often indicative activity these fungi. Root traditionally measured with microscopy methods which visualize fungal structures inside roots. Microscopy labor-intensive, and results depend on observer. In this study, we present a relative qPCR method to quantify normalized signal gene. First, validated...