sp. nov., a novel rhizobial species isolated from nodules.

Three slow-growing rhizobial strains, designated as 1AS2L, 1AS20L and 1AS5L, were isolated from nodules of in Borj Cedria, northern Tunisia. These strains, which belong to the symbiovar cyanophyllae, were characterized using a polyphasic approach. Phylogenetic analysis of the 16S rRNA () gene placed these strains within the genus , specifically in the superclade associated with .

A transcriptomic perspective of P trade in mycorrhizal grapevine.

Nutrient exchanges are a key feature of arbuscular mycorrhizal (AM) symbiosis. Grapevine (Vitis vinifera), one of the most economically important crops worldwide, relies heavily on AM symbiosis for its growth and development. Since the phylloxera crisis, cultivated grapevines are obtained by grafting a Vitis vinifera scion onto a rootstock.

Toward deciphering the molecular dialogue in the rhizomicrobiota: Transcriptomic profiling of Trichoderma in rhizobia interaction.

Microbial interactions are of key importance for the emergent properties of microbiota and ecosystems, playing a pivotal role in plant health, growth, and productivity. This study explores the interactions between soil fungi and rhizosphere bacteria, focusing specifically on fungi belonging to the genus Trichoderma and the plant symbiotic bacterium Sinorhizobium meliloti. Our aim is to provide evidence of the impact of different strains of the same bacterial species on the fungus.

The nuclear dynamic of CDC48 is affected during the immune response in plants.

Plants are continuously challenged by a myriad of pathogenic microorganisms, including bacteria, viruses, fungi and oomycetes, against which they must defend themselves. The protein Cell Division Cycle 48 (CDC48), a key player of ubiquitin-proteasome system which segregates and remodels ubiquitinated proteins for degradation, is known to be mobilized during plant immunity. Moreover, the characterization of the nuclear role of CDC48 is of interest, in particular its regulation in nuclear processes such as chromatin remodeling, DNA repair and gene expression.

The C24-methyl/ethyl sterol ratio is increased by Rhizophagus irregularis colonization.

Plant-microorganism interactions underlie many ecosystem roles, in particular the enhancement of plant nutrition through mutualistic relationships, such as the arbuscular mycorrhizal symbiosis that affects a large proportion of land plants. The establishment of this interaction induces a wide range of signaling pathways in which lipids, and particularly sterols, may play a central role. However, their supported functions are poorly known.

Genotype-by-genotype interkingdom cross-talk between symbiotic nitrogen fixing Sinorhizobium meliloti strains and Trichoderma species.

In the understanding of the molecular interaction between plants and their microbiome, a key point is to identify simplified models of the microbiome including relevant bacterial and fungal partners which could also be effective in plant growth promotion. Here, as proof-of-concept, we aim to identify the possible molecular interactions between symbiotic nitrogen-fixing rhizobia and soil fungi (Trichoderma spp.), hence shed light on synergistic roles rhizospheric fungi could have in the biology of symbiotic nitrogen fixation bacteria.

Wheat dwarfing reshapes plant and fungal development in arbuscular mycorrhizal symbiosis.

The introduction of Reduced height (Rht) dwarfing genes into elite wheat varieties has contributed to enhanced yield gain in high input agrosystems by preventing lodging. Yet, how modern selection for dwarfing has affected symbiosis remains poorly documented. In this study, we evaluated the response of both the plant and the arbuscular mycorrhizal fungus to plant genetic variation at a major Quantitative Trait Locus called QTL 4B2, known to harbor a Rht dwarfing gene, when forming the symbiosis.

Arbuscular mycorrhizal symbiosis with Rhizophagus irregularis DAOM197198 modifies the root transcriptome of walnut trees.

Walnut trees are cultivated and exploited worldwide for commercial timber and nut production. They are heterografted plants, with the rootstock selected to grow in different soil types and conditions and to provide the best anchorage, vigor, and resistance or tolerance to soil borne pests and diseases. However, no individual rootstock is tolerant of all factors that impact walnut production.

Sterols, pleiotropic players in plant-microbe interactions.

Plant-microbe interactions (PMIs) are regulated through a wide range of mechanisms in which sterols from plants and microbes are involved in numerous ways, including recognition, transduction, communication, and/or exchanges between partners. Phytosterol equilibrium is regulated by PMIs through expression of genes involved in phytosterol biosynthesis, together with their accumulation. As such, PMI outcomes also include plasma membrane (PM) functionalization events, in which phytosterols have a central role, and activation of sterol-interacting proteins involved in cell signaling.

CDC48 in plants and its emerging function in plant immunity.

Protein homeostasis, namely the balance between protein synthesis and degradation, must be finely controlled to ensure cell survival, notably through the ubiquitin-proteasome system (UPS). In all species, including plants, homeostasis is disrupted by biotic and abiotic stresses. A key player in the maintenance of protein balance, the protein CDC48, shows emerging functions in plants, particularly in response to biotic stress.

Comparative RNA sequencing-based transcriptome profiling of ten grapevine rootstocks: shared and specific sets of genes respond to mycorrhizal symbiosis.

Arbuscular mycorrhizal symbiosis improves water and nutrient uptake by plants and provides them other ecosystem services. Grapevine is one of the major crops in the world. Vitis vinifera scions generally are grafted onto a variety of rootstocks that confer different levels of resistance against different pests, tolerance to environmental stress, and influence the physiology of the scions.

Arbuscular mycorrhizal fungal communities differ in neighboring vineyards of different ages.

Arbuscular mycorrhizal fungi (AMF) are key organisms in viticultural ecosystems as they provide many ecosystem services to soils and plants. Data about AMF community dynamics over time are relatively scarce and at short time scales. Many factors such as the soil, climate, and agricultural practices could modify the dynamics and functions of microbial communities.

sp. nov., a new nitrogen-fixing symbiovar isolated from root nodules of in Tunisia.

Three bacterial strains, 1AS11, 1AS12 and 1AS13, members of the new symbiovar salignae and isolated from root nodules of grown in Tunisia, were characterized using a polyphasic approach. All three strains were assigned to the complex on the basis of gene analysis. Phylogenetic analysis based on 1734 nucleotides of four concatenated housekeeping genes (, , and ) showed that the three strains were distinct from known rhizobia species of the complex and clustered as a separate clade within this complex.

The giant diploid faba genome unlocks variation in a global protein crop.

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emissions and loss of biodiversity. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value. Faba bean (Vicia faba L.

Nitrogen Acquisition and Transport in the Ectomycorrhizal Symbiosis-Insights from the Interaction between an Oak Tree and .

In temperate forests, the roots of various tree species are colonized by ectomycorrhizal fungi, which have a key role in the nitrogen nutrition of their hosts. However, not much is known about the molecular mechanisms related to nitrogen metabolism in ectomycorrhizal plants. This study aimed to evaluate the nitrogen metabolic response of oak plants when inoculated with the ectomycorrhizal fungus Pisolithus tinctorius.

The ecologically relevant genetics of plant-plant interactions.

Interactions among plants have been long recognized as a major force driving plant community dynamics and crop yield. Surprisingly, our knowledge of the ecological genetics associated with variation of plant-plant interactions remains limited. In this opinion article by scientists from complementary disciplines, the international PLANTCOM network identified four timely questions to foster a better understanding of the mechanisms mediating plant assemblages.

The microbiota of the grapevine holobiont: A key component of plant health.

Background: Grapevine is a woody, perennial plant of high economic importance worldwide. Like other plants, it lives in close association with large numbers of microorganisms. Bacteria, fungi and viruses are structured in communities, and each individual can be beneficial, neutral or harmful to the plant.

The fine-tuning of mycorrhizal pathway in sorghum depends on both nitrogen-phosphorus availability and the identity of the fungal partner.

Sorghum is an important worldwide source of food, feed and fibres. Like most plants, it forms mutualistic symbioses with arbuscular mycorrhizal fungi (AMF), but the nutritional basis of mycorrhiza-responsiveness is largely unknown. Here, we investigated the transcriptional and physiological responses of sorghum to two different AMF species, Rhizophagus irregularis and Funneliformis mosseae, under 16 different conditions of nitrogen (N) and phosphorus (P) supply.

Genotypic and symbiotic diversity studies of rhizobia nodulating Acacia saligna in Tunisia reveal two novel symbiovars within the Rhizobium leguminosarum complex and Bradyrhizobium.

Acacia saligna is an invasive alien species that has the ability to establish symbiotic relationships with rhizobia. In the present study, genotypic and symbiotic diversity of native rhizobia associated with A. saligna in Tunisia were studied.

Imaging plant tissues: advances and promising clearing practices.

The study of the organ structure of plants and understanding their physiological complexity requires 3D imaging with subcellular resolution. Most plant organs are highly opaque to light, and their study under optical sectioning microscopes is therefore difficult. In animals, many protocols have been developed to make organs transparent to light using clearing protocols (CPs).

Successional adaptive strategies revealed by correlating arbuscular mycorrhizal fungal abundance with host plant gene expression.

The shifts in adaptive strategies revealed by ecological succession and the mechanisms that facilitate these shifts are fundamental to ecology. These adaptive strategies could be particularly important in communities of arbuscular mycorrhizal fungi (AMF) mutualistic with sorghum, where strong AMF succession replaces initially ruderal species with competitive ones and where the strongest plant response to drought is to manage these AMF. Although most studies of agriculturally important fungi focus on parasites, the mutualistic symbionts, AMF, constitute a research system of human-associated fungi whose relative simplicity and synchrony are conducive to experimental ecology.

The ROP3 Is Involved in the Establishment of the Nitrogen-Fixing Symbiosis but Not of the Arbuscular Mycorrhizal Symbiosis.

Legumes form root mutualistic symbioses with some soil microbes promoting their growth, rhizobia, and arbuscular mycorrhizal fungi (AMF). A conserved set of plant proteins rules the transduction of symbiotic signals from rhizobia and AMF in a so-called common symbiotic signaling pathway (CSSP). Despite considerable efforts and advances over the past 20 years, there are still key elements to be discovered about the establishment of these root symbioses.