Tomato domestication rather than subsequent breeding events reduces microbial associations related to phosphorus recovery.

Legacy phosphorus (P) is a reservoir of sparingly available P, and its recovery could enhance sustainable use of nonrenewable mineral fertilizers. Domestication has affected P acquisition, but it is unknown if subsequent breeding efforts, like the Green Revolution (GR), had a similar effect. We examined how domestication and breeding events altered P acquisition by growing wild, traditional (pre-GR), and modern (post-GR) tomato in soil with legacy P but low bioavailable P.

Harnessing Phosphorous (P) Fertilizer-Insensitive Bacteria to Enhance Rhizosphere P Bioavailability in Legumes.

Phosphorous (P) is widely used in agriculture; yet, P fertilizers are a nonrenewable resource. Thus, mechanisms to improve soil P bioavailability need to be found. Legumes are efficient in P acquisition and, therefore, could be used to develop new technologies to improve soil P bioavailability.

Shifts of the soil microbiome composition induced by plant-plant interactions under increasing cover crop densities and diversities.

Interspecific and intraspecific competition and facilitation have been a focus of study in plant-plant interactions, but their influence on plant recruitment of soil microbes is unknown. In this greenhouse microcosm experiment, three cover crops (alfalfa, brassica, and fescue) were grown alone, in paired mixtures, and all together under different densities. For all monoculture trials, total pot biomass increased as density increased.

A Microbiological Approach to Alleviate Soil Replant Syndrome in Peaches.

Replant syndrome (RS) is a global problem characterized by reduced growth, production life, and yields of tree fruit/nut orchards. RS etiology is unclear, but repeated monoculture plantings are thought to develop a pathogenic soil microbiome. This study aimed to evaluate a biological approach that could reduce RS in peach () orchards by developing a healthy soil bacteriome.

Root exudate-derived compounds stimulate the phosphorus solubilizing ability of bacteria.

Low phosphorus (P) availability in soils is a major challenge for sustainable food production, as most soil P is often unavailable for plant uptake and effective strategies to access this P are limited. Certain soil occurring bacteria and root exudate-derived compounds that release P are in combination promising tools to develop applications that increase phosphorus use efficiency in crops. Here, we studied the ability of root exudate compounds (galactinol, threonine, and 4-hydroxybutyric acid) induced under low P conditions to stimulate the ability of bacteria to solubilize P.

The rhizosphere microbiome: Plant-microbial interactions for resource acquisition.

While horticulture tools and methods have been extensively developed to improve the management of crops, systems to harness the rhizosphere microbiome to benefit plant crops are still in development. Plants and microbes have been coevolving for several millennia, conferring fitness advantages that expand the plant's own genetic potential. These beneficial associations allow the plants to cope with abiotic stresses such as nutrient deficiency across a wide range of soils and growing conditions.

Soil microbiome disruption reveals specific and general plant-bacterial relationships in three agroecosystem soils.

Soil microbiome disruption methods are regularly used to reduce populations of microbial pathogens, often resulting in increased crop growth. However, little is known about the effect of soil microbiome disruption on non-pathogenic members of the soil microbiome. Here, we applied soil microbiome disruption in the form of moist-heat sterilization (autoclaving) to reduce populations of naturally occurring soil microbiota.

Conditioned soils reveal plant-selected microbial communities that impact plant drought response.

Rhizobacterial communities can contribute to plant trait expression and performance, including plant tolerance against abiotic stresses such as drought. The conditioning of microbial communities related to disease resistance over generations has been shown to develop suppressive soils which aid in plant defense responses. Here, we applied this concept for the development of drought resistant soils.

Methods for Root Exudate Collection and Analysis.

Plant root exudation has long been recognized as a vital communication system between plants and microbial communities populating the rhizosphere. Due to the high complexity of the collection process and analysis, a variety of techniques have been developed to mimic natural exudation conditions. In addition, significant progress improving existing techniques and developing new methodologies of root exudate collection and analysis have been made.

Root exudates drive soil-microbe-nutrient feedbacks in response to plant growth.

Although interactions between plants and microbes at the plant-soil interface are known to be important for plant nutrient acquisition, relatively little is known about how root exudates contribute to nutrient exchange over the course of plant development. In this study, root exudates from slow- and fast-growing stages of Arabidopsis thaliana plants were collected, chemically analysed and then applied to a sandy nutrient-depleted soil. We then tracked the impacts of these exudates on soil bacterial communities, soil nutrients (ammonium, nitrate, available phosphorus and potassium) and plant growth.

Role of root exudates on assimilation of phosphorus in young and old Arabidopsis thaliana plants.

The role of root exudates has long been recognized for its potential to improve nutrient use efficiency in cropping systems. However, studies addressing the variability of root exudates involved in phosphorus solubilization across plant developmental stages remain scarce. Here, we grew Arabidopsis thaliana seedlings in sterile liquid culture with a low, medium, or high concentration of phosphate and measured the composition of the root exudate at seedling, vegetative, and bolting stages.

Differential Effects of Phosphorus Fertilization on Plant Uptake and Rhizosphere Microbiome of Cultivated and Non-cultivated Potatoes.

There is evidence that shows that phosphorus (P) fertilization has a moderate effect on the rhizosphere microbial composition of cultivated crops. But how this effect is manifested on wild species of the same crop is not clear. This study compares the impact of phosphorus fertilization with rhizosphere bacterial community composition and its predicted functions, related to P-cycling genes, in both cultivated and non-cultivated potato (Solanum sp.

Isolation of Klebsiella pneumoniae and Pseudomonas aeruginosa from entomopathogenic nematode-insect host relationship to examine bacterial pathogenicity on Trichoplusia ni.

Klebsiella pneumoniae was isolated from infected pupae of Galleria mellonella and Pseudomonas aeruginosa was isolated from the entomopathogenic nematode Heterorhabditis bacteriophora hosted within the pupae of G. mellonella. Insect consumption and surface application of P.

A novel approach to determine generalist nematophagous microbes reveals Mortierella globalpina as a new biocontrol agent against Meloidogyne spp. nematodes.

Root-knot nematodes (RKN) such as Meloidogyne spp. are among the most detrimental pests in agriculture affecting several crops. New methodologies to manage RKN are needed such as efficient discovery of nematophagous microbes.

Trichoderma gamsii affected herbivore feeding behaviour on Arabidopsis thaliana by modifying the leaf metabolome and phytohormones.

Plants can re-programme their transcriptome, proteome and metabolome to deal with environmental and biotic stress. It has been shown that the rhizosphere microbiome has influence on the plant metabolome and on herbivore behaviour. In the present study, Trichoderma gamsii was isolated from Arabidopsis thaliana rhizosphere soil.

Root exudates drive the soil-borne legacy of aboveground pathogen infection.

Background: Plants are capable of building up beneficial rhizosphere communities as is evidenced by disease-suppressive soils. However, it is not known how and why soil bacterial communities are impacted by plant exposure to foliar pathogens and if such responses might improve plant performance in the presence of the pathogen. Here, we conditioned soil by growing multiple generations (five) of Arabidopsis thaliana inoculated aboveground with Pseudomonas syringae pv tomato (Pst) in the same soil.

Bacterial Microbiome and Nematode Occurrence in Different Potato Agricultural Soils.

Pratylenchus neglectus and Meloidogyne chitwoodi are the main plant-parasitic nematodes in potato crops of the San Luis Valley, Colorado. Bacterial microbiome (16S rRNA copies per gram of soil) and nematode communities (nematodes per 200 g of soil) from five different potato farms were analyzed to determine negative and positive correlations between any bacterial genus and P. neglectus and M.

Plant-insect-pathogen interactions: a naturally complex ménage à trois.

Under environmental conditions, plants are constantly exposed to a wide range of biotic interactions, which include insects, and pathogens. Usually scientists are tempted to study each association individually, which reduces the complexity of the interaction. This restricted view of the problem does not consider that plants are the ballroom in which a multitude of organisms are constantly interacting with each other affecting not only plant responses but also how one organism responds to the other.

The unseen rhizosphere root-soil-microbe interactions for crop production.

The underground root-soil-microbe interactions are extremely complex, but vitally important for aboveground plant growth, health and fitness. The pressure to reduce our reliance on agrochemicals, and sustainable efforts to develop agriculture makes rhizosphere interactions' research a hotspot. Recent advances provide new insights about the signals, pathways, functions and mechanisms of these interactions.

Supplementing Blends of Sugars, Amino Acids, and Secondary Metabolites to the Diet of Termites (Reticulitermes flavipes) Drive Distinct Gut Bacterial Communities.

Although it is well known that diet is one of the major modulators of the gut microbiome, how the major components of diet shape the gut microbial community is not well understood. Here, we developed a simple system that allows the investigation of the impact of given compounds as supplements of the diet on the termite gut microbiome. The 16S rRNA pyrosequencing analysis revealed that feeding termites different blends of sugars and amino acids did not majorly impact gut community composition; however, ingestion of blends of secondary metabolites caused shifts in gut bacterial community composition.

Soil memory as a potential mechanism for encouraging sustainable plant health and productivity.

The unspecified components of plant-microbe and plant-microbiome associations in the rhizosphere are complex, but recent research is simplifying our understanding of these relationships. We propose that the strong association between hosts, symbionts, and pathogens could be simplified by the concept of soil memory, which explains how a plant could promote their fecundity and protect their offspring through tightly associated relationships with the soil. Although there are many questions surrounding the mechanisms of this phenomenon, recent research has exposed evidence of its existence.

Organic acids from root exudates of banana help root colonization of PGPR strain Bacillus amyloliquefaciens NJN-6.

The successful colonization of plant growth promoting rhizobacteria (PGPR) in the rhizosphere is an initial and compulsory step in the protection of plants from soil-borne pathogens. Therefore, it is necessary to evaluate the role of root exudates in the colonization of PGPR. Banana root exudates were analyzed by high pressure liquid chromatography (HPLC) which revealed exudates contained several organic acids (OAs) including oxalic, malic and fumaric acid.

Linking Jasmonic Acid Signaling, Root Exudates, and Rhizosphere Microbiomes.

Jasmonic acid (JA) is an essential hormone in plant development and defense responses in Arabidopsis thaliana. Exogenous treatment with JA has recently been shown to alter root exudate profiles and the composition of root-associated bacterial communities. However, it is currently unknown whether disruptions of the JA in the rhizosphere affect root exudation profiles and the relative abundance of bacteria and archaea in the rhizosphere.

Plant-plant-microbe mechanisms involved in soil-borne disease suppression on a maize and pepper intercropping system.

Background: Intercropping systems could increase crop diversity and avoid vulnerability to biotic stresses. Most studies have shown that intercropping can provide relief to crops against wind-dispersed pathogens. However, there was limited data on how the practice of intercropping help crops against soil-borne Phytophthora disease.