The root microbiota plays a vital role in plant growth and health. Recently, Zhang and colleagues demonstrated that the rhizobacterial strain Exiguobacterium R2567 produces cyclo(Leu-Pro), a cyclic dipeptide that regulates tillering by activating the rice strigolactone (SL) signaling pathway through binding to the SL receptor OsD14. This discovery provides an innovative strategy for optimizing crop architecture by harnessing the root microbiota for sustainable agriculture. It holds promise for achieving precision and environmentally friendly production through the application of synthetic microbial communities (SynComs) or functional metabolites. However, practical implementation faces challenges, including the field stability of cyclo(Leu-Pro), competition from native microbial communities, and potential long-term ecological risks, which require further study to realize its full potential.

Phyllosphere microbiota play crucial roles in supporting host performance. However, the dynamic changes of phyllosphere-associated microbiome during pathogen infections and their impacts on plant health remain unknown. Here, we found phyllosphere microbes can mitigate wheat Fusarium head blight (FHB), a severe disease caused by Fusarium graminearum (F. graminearum) pathogen that promotes infection by inducing host alkalinization. Using wheat head microbial community profiling and metatranscriptomics, we found Pseudomonas spp. significantly enriched on infected wheat heads. Through isolating 595 bacterial strains from infected wheat heads—including 196 Pseudomonas isolates—we identified certain enriched Pseudomonas isolates capable of producing organic acids that counteract pathogen-induced pH upshift. In vitro experiments confirm the selective promotion of specific host-acidifying Pseudomonas in wheat heads. Field trials confirmed that host-acidifying Pseudomonas strains effectively controlled FHB. These findings highlight the pivotal role of plant-beneficial microbes in host pH regulation and offer innovative avenues for sustainable plant disease control.

A new fossil fungus discovered in Scotland shows evidence of plants and fungi sharing nutrients to survive on land.

The Agrobiology and Soil Management Group (University of Barcelona) invites applications for a 12-month postdoctoral position (part-time, 0.5 FTE) focused on developing and validating machine learning...

Common mycorrhizal networks (CMNs) formed by arbuscular mycorrhizal fungi interconnect neighbouring plants. New evidence from Zhang et al. demonstrates that CMNs transfer jasmonic acid from necrotroph...

Le colloque « La Palestine et l’Europe » se tiendra les 13 et 14 novembre, réaffirmant la liberté académique et le partage du savoir.

Fe, an essential element for plants to sustain central biological functions, recently emerged as a modulator of immunity. However, our understanding o…

Hou et al. engineer plant endophytes to express effectors that trigger NLR-mediated ETI upon pathogen infection, regardless of whether pathogens carry recognizable effectors. The sentinel bacterium ma...

Plants establish symbiotic relationships with various mycorrhizal fungi, which may represent a crucial mechanism for different modes of nutrient cycling and soil ecological processes. However, our understanding of rhizosphere-specific microbial traits—such as fungal functional guilds and bacterial life-history strategies (copiotrophic vs. oligotrophic)—at the individual mycorrhizal tree species level remains limited. In this study, we examined how N addition (47.5 g N m−2 yr−1) affects bacterial and fungal communities in the rhizosphere of two dominant subtropical tree species: Castanopsis hystrix, an ectomycorrhizal (ECM) tree species, and Phoebe bournei, an arbuscular mycorrhizal (AM) tree species. We used amplicon sequencing and ecological trait-based analyses to conduct this research. Nitrogen enrichment led to a reduction in bacterial α-diversity, favouring copiotrophic Gammaproteobacteria and r-strategists while suppressing oligotrophic groups, such as Acidobacteriia, Alphaproteobacteria, and Acidimicrobiia, along with K-strategists. Furthermore, adding N increased heterogeneity in bacterial β-diversity between mycorrhizal plant types, resulting in divergent shifts in copiotrophic and oligotrophic bacterial groups. This shift amplified community differentiation specific to the mycorrhizal plant type rather than promoting convergence. Fungal responses to N addition varied based on the host mycorrhizal plant type. In AM-associated P. bournei, N addition decreased the relative abundance of symbiotrophic AM fungi and reduced fungal α-diversity. Conversely, in ECM-associated C. hystrix, N addition suppressed both saprotrophic and symbiotrophic ECM fungi while increasing α-diversity, likely due to the growth of pathotrophic taxa. Despite these contrasting responses, N addition homogenised fungal β-diversity across mycorrhizal plant types, reducing differences among mycorrhizal-specific fungal guilds. Structural equation modelling revealed that soil N and P availability were the primary drivers of bacterial community restructuring. In contrast, fungal assemblages were impacted by both soil chemistry and root traits, notably fine root length. These findings highlight that N enrichment disrupts mycorrhizal plant type-specific microbial niche partitioning in subtropical forests, favouring copiotrophic bacteria and separating fungal communities from host identities, a potential mechanism driving ecosystem-level functional changes under elevated N deposition.

L’annulation, sous pression du ministre de l’enseignement supérieur et de la recherche, d’un colloque du Collège de France consacré à la Palestine, constitue un opprobre démocratique et scientifique.

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...

Research Associate: Plant-fungal interactions

Metagenomes from prairie soils in Kansas, USA, show how historical exposure to water stress impacts soil microorganisms and subsequently drought responses in plants.

Arbuscular mycorrhizal (AM) symbiosis develops through successive colonization of root epidermal and cortical cells, culminating in the formation of arbuscules, tree-like intracellular structures that...

An investigation of plant receptor-like kinases identifies regions of these proteins that control whether immune or symbiotic signalling pathways are activated, with minimal changes to specific r...

Abstract. Plants and microbes use many strategies to acquire soil amino acids. Recent findings suggest that genes related to amino acid metabolism and tran

Abstract. Bacteriophages, lytic or lysogenic, play critical roles in structuring different soil bacteriomes and driving their functionality. Lysogeny is fa

Crop domestication has revolutionized food production but increased agriculture’s reliance on fertilizers and pesticides. We investigate differences in the rhizosphere microbiome functions of wild and domesticated rice, focusing on nitrogen (N) cycling genes. Shotgun metagenomics and real-time PCR reveal a higher abundance of N-fixing genes in the wild rice rhizosphere microbiomes. Validation through transplanting rhizosphere microbiome suspensions shows the highest nitrogenase activity in soils with wild rice suspensions, regardless of planted rice type. Domesticated rice, however, exhibits an increased number of genes associated with nitrous oxide (N2O) production. Measurements of N2O emissions in soils with wild and domesticated rice are significantly higher in soil with domesticated rice compared to wild rice. Comparative root metabolomics between wild and domesticated rice further show that wild rice root exudates positively correlate with the frequency and abundance of microbial N-fixing genes, as indicated by metagenomic and qPCR, respectively. To confirm, we add wild and domesticated rice root metabolites to black soil, and qPCR shows that wild rice exudates maximize microbial N-fixing gene abundances and nitrogenase activity. Collectively, these findings suggest that rice domestication negatively impacts N-fixing bacteria and enriches bacteria that produce the greenhouse gas N2O, highlighting the environmental trade-offs associated with crop domestication.

Symbioses have been fundamental to colonization of terrestrial ecosystems by plants and their evolution. Emergence of the ancient arbuscular mycorrhizal symbiosis was followed by the diversification of alternative intracellular symbioses, such as the ericoid mycorrhizae (ErM). We aimed at understanding how these diversifications occurred. We sequenced the genomes of ErM-forming liverworts, and reconstituted symbiosis under laboratory conditions. We demonstrated the existence of a nutrient-regulated symbiotic state that enables ErM and underlies intracellular colonization of plant tissues. Comparative transcriptomic analyses identified an ancestral gene module associated with intracellular symbiosis beyond ErM. Genetic manipulations in the liverwort Marchantia paleacea, phylogenetics and transactivation assays demonstrated its essential function for intracellular symbiosis. We conclude that plant have maintained, and convergently recruited, an ancestral gene module for intracellular symbioses.