Seed tuber microbiome can predict growth potential of potato varieties.

Potato vigour, the growth potential of seed potatoes, is a key agronomic trait that varies significantly across production fields due to factors such as genetic background and environmental conditions. Seed tuber microbiomes are thought to influence plant health and crop performance, yet the precise relationships between microbiome composition and potato vigour remain unclear. Here we conducted microbiome sequencing on seed tuber eyes and heel ends from 6 potato varieties grown in 240 fields.

Coumarin biosynthesis genes are required after foliar pathogen infection for the creation of a microbial soil-borne legacy that primes plants for SA-dependent defenses.

Plants deposit photosynthetically-fixed carbon in the rhizosphere, the thin soil layer directly around the root, thereby creating a hospitable environment for microbes. To manage the inhabitants of this nutrient-rich environment, plant roots exude and dynamically adjust microbe-attracting and -repelling compounds to stimulate specific members of the microbiome. Previously, we demonstrated that foliar infection of Arabidopsis thaliana by the biotrophic downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa) leads to a disease-induced modification of the rhizosphere microbiome.

The secret life of plant-beneficial rhizosphere bacteria: insects as alternative hosts.

Root-colonizing bacteria have been intensively investigated for their intimate relationship with plants and their manifold plant-beneficial activities. They can inhibit growth and activity of pathogens or induce defence responses. In recent years, evidence has emerged that several plant-beneficial rhizosphere bacteria do not only associate with plants but also with insects.

Experimental-Evolution-Driven Identification of Rhizosphere Competence Genes in Pseudomonas protegens.

Beneficial plant root-associated microorganisms carry out a range of functions that are essential for plant performance. Establishment of a bacterium on plant roots, however, requires overcoming several challenges, including competition with neighboring microorganisms and host immunity. Forward and reverse genetics have led to the identification of mechanisms that are used by beneficial microorganisms to overcome these challenges, such as the production of iron-chelating compounds, the formation of strong biofilms, or the concealment of characteristic microbial molecular patterns that trigger the host immune system.

Transcriptome Signatures in WCS417 Shed Light on Role of Root-Secreted Coumarins in -Mutualist Communication.

WCS417 is a root-colonizing bacterium with well-established plant-beneficial effects. Upon colonization of roots, WCS417 evades local root immune responses while triggering an induced systemic resistance (ISR) in the leaves. The early onset of ISR in roots shows similarities with the iron deficiency response, as both responses are associated with the production and secretion of coumarins.

Collection of Sterile Root Exudates from Foliar Pathogen-Inoculated Plants.

In nature and agriculture, plants interact with an astonishing number of microbes, collectively referred to as the "plant microbiome." Roots are a microbial hotspot where beneficial plant-microbe interactions are established that support plant growth and provide protection against pathogens and insects. Recently, we discovered that in response to foliar pathogen attack, plant roots can recruit specific protective microbes into the rhizosphere.

Soil-Borne Legacies of Disease in Arabidopsis thaliana.

The rhizosphere microbiome of plants is essential for plant growth and health. Recent studies have shown that upon infection of leaves with a foliar pathogen, the composition of the root microbiome is altered and enriched with bacteria that in turn can systemically protect the plant against the foliar pathogen. This protective effect is extended to successive populations of plants that are grown on soil that was first conditioned by pathogen-infected plants, a phenomenon that was coined "the soil-borne legacy.

The Soil-Borne Identity and Microbiome-Assisted Agriculture: Looking Back to the Future.

Looking forward includes looking back every now and then. In 2007, David Weller looked back at 30 years of biocontrol of soil-borne pathogens by Pseudomonas and signified that the progress made over decades of research has provided a firm foundation to formulate current and future research questions. It has been recognized for more than a century that soil-borne microbes play a significant role in plant growth and health.

Rhizosphere-Associated Pseudomonas Suppress Local Root Immune Responses by Gluconic Acid-Mediated Lowering of Environmental pH.

The root microbiome consists of commensal, pathogenic, and plant-beneficial microbes [1]. Most members of the root microbiome possess microbe-associated molecular patterns (MAMPs) similar to those of plant pathogens [2]. Their recognition can lead to the activation of host immunity and suppression of plant growth due to growth-defense tradeoffs [3, 4].

Type III Secretion System of Beneficial Rhizobacteria WCS417 and WCS374.

Plants roots host myriads of microbes, some of which enhance the defense potential of plants by activating a broad-spectrum immune response in leaves, known as induced systemic resistance (ISR). Nevertheless, establishment of this mutualistic interaction requires active suppression of local root immune responses to allow successful colonization. To facilitate host colonization, phytopathogenic bacteria secrete immune-suppressive effectors into host cells via the type III secretion system (T3SS).

Beneficial microbes going underground of root immunity.

Plant roots interact with an enormous diversity of commensal, mutualistic, and pathogenic microbes, which poses a big challenge to roots to distinguish beneficial microbes from harmful ones. Plants can effectively ward off pathogens following immune recognition of conserved microbe-associated molecular patterns (MAMPs). However, such immune elicitors are essentially not different from those of neutral and beneficial microbes that are abundantly present in the root microbiome.

A Comparative Review on Microbiota Manipulation: Lessons From Fish, Plants, Livestock, and Human Research.

During recent years the impact of microbial communities on the health of their host (being plants, fish, and terrestrial animals including humans) has received increasing attention. The microbiota provides the host with nutrients, induces host immune development and metabolism, and protects the host against invading pathogens (1-6). Through millions of years of co-evolution bacteria and hosts have developed intimate relationships.

[Migrants' motives and expectations for contacting out-of-hours primary care].

Background: Migrants relatively often use out-of-hours primary care. The objective of this study is to examine the motives and expectations of migrants for contacting out-of-hours primary care.

Methods: We used data from a survey study of 11,483 patients who contacted a General Practitioner (GP) cooperative in the Netherlands between 2009 and 2014 (response rate 45.

MYB72-dependent coumarin exudation shapes root microbiome assembly to promote plant health.

Plant roots nurture a tremendous diversity of microbes via exudation of photosynthetically fixed carbon sources. In turn, probiotic members of the root microbiome promote plant growth and protect the host plant against pathogens and pests. In the - WCS417 model system the root-specific transcription factor MYB72 and the MYB72-controlled β-glucosidase BGLU42 emerged as important regulators of beneficial rhizobacteria-induced systemic resistance (ISR) and iron-uptake responses.

The Soil-Borne Legacy.

Plants greatly rely on their root microbiome for uptake of nutrients and protection against stresses. Recent studies have uncovered the involvement of plant stress responses in the assembly of plant-beneficial microbiomes. To facilitate durable crop production, deciphering the driving forces that shape the microbiome is crucial.

Disease-induced assemblage of a plant-beneficial bacterial consortium.

Disease suppressive soils typically develop after a disease outbreak due to the subsequent assembly of protective microbiota in the rhizosphere. The role of the plant immune system in the assemblage of a protective rhizosphere microbiome is largely unknown. In this study, we demonstrate that Arabidopsis thaliana specifically promotes three bacterial species in the rhizosphere upon foliar defense activation by the downy mildew pathogen Hyaloperonospora arabidopsidis.

Migrants' motives and expectations for contacting out-of-hours primary care: a survey study.

Background: Migrants are more likely to use out-of-hours primary care, especially for nonurgent problems. Their motives and expectations for help-seeking are as yet unknown. The objective of this study is to examine the motives and expectations of migrants for contacting out-of-hours primary care.

Iron and Immunity.

Iron is an essential nutrient for most life on Earth because it functions as a crucial redox catalyst in many cellular processes. However, when present in excess iron can lead to the formation of harmful hydroxyl radicals. Hence, the cellular iron balance must be tightly controlled.

Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria.

The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Here, we performed a genome-wide association (GWA) study on natural genetic variation in Arabidopsis for the ability to profit from rhizobacteria-mediated plant growth-promotion.

Unearthing the genomes of plant-beneficial Pseudomonas model strains WCS358, WCS374 and WCS417.

Background: Plant growth-promoting rhizobacteria (PGPR) can protect plants against pathogenic microbes through a diversity of mechanisms including competition for nutrients, production of antibiotics, and stimulation of the host immune system, a phenomenon called induced systemic resistance (ISR). In the past 30 years, the Pseudomonas spp. PGPR strains WCS358, WCS374 and WCS417 of the Willie Commelin Scholten (WCS) collection have been studied in detail in pioneering papers on the molecular basis of PGPR-mediated ISR and mechanisms of biological control of soil-borne pathogens via siderophore-mediated competition for iron.