DAY 2Wednesday, 2 December 2026 - America/Los_Angeles (UTC-08:00)

Microbial biostimulants offer a sustainable strategy to improve crop productivity, yet their interactions with resident rhizosphere microbial communities remain poorly understood. We evaluated the effects of inoculating greenhouse-grown French marigold (Tagetes patula) and tomato (Solanum lycopersicum) with the siderophore-producing bacterium Pseudomonas soli C10A8 under phosphorus-limited conditions created using the ferrous sulfate bridge method, which immobilizes phosphate as insoluble iron-phosphate complexes. Rhizosphere bacterial (16S rRNA) and fungal (ITS) communities were characterized using amplicon sequencing to determine host-specific microbiome responses to inoculation. Inoculation with C10A8 improved plant growth and phosphorus acquisition in both crop species. However, microbiome responses differed markedly between hosts. Tomato rhizosphere bacterial communities differed significantly between inoculated and non-inoculated plants (PERMANOVA, Bray-Curtis, R2 = 0.458, p = 0.002), and fungal communities also differed significantly (R2 = 0.444, p = 0.006). In contrast, neither bacterial (R2 = 0.117, p = 0.169) nor fungal (R2 = 0.154, p = 0.138) communities differed significantly in marigold following inoculation, despite successful detection of C10A8 in the rhizosphere. These contrasting responses indicate that inoculant establishment does not necessarily correspond with broad microbiome restructuring and that host identity strongly influences microbial community responses to biostimulant application. These findings demonstrate that microbial biostimulants can produce distinct, host-dependent ecological responses while promoting plant performance. Understanding how crop species influence microbiome assembly following inoculation will improve the development of more reliable microbial biostimulants and inform the design of next-generation microbial consortia for sustainable greenhouse production.

Successful crop establishment depends on interactions among seed, soil, and environmental conditions during germination and early seedling development. Suboptimal soil temperatures, including both cold and excessively warm conditions, can delay emergence, reduce stand uniformity, impair root development, and limit yield potential. These challenges are becoming more significant as planting windows narrow and early-season weather becomes increasingly variable.
Microbial biostimulants can enhance early plant growth, but the performance of many rhizosphere microorganisms is strongly influenced by soil temperature. Reduced activity in cold soils or impaired survival under heat stress can limit field consistency. Therefore, microbial efficacy across a broad temperature range represents an important but underexplored trait for improving crop establishment.
A proprietary strain of Bacillus velezensis with multiple plant growth-promoting mechanisms was evaluated for its ability to maintain activity under temperature stress. Controlled-environment and greenhouse studies showed that the strain remained functional under temperatures that commonly inhibit seedling growth and reduce the effectiveness of other plant growth-promoting rhizobacteria. Treatment accelerated emergence, improved emergence uniformity, enhanced root and shoot growth, and increased early-season vigor under both low- and high-temperature conditions.
Field trials across multiple crops, environments, and planting conditions confirmed the agronomic relevance of this temperature-resilient phenotype. Improved early establishment resulted in stronger stands, more vigorous canopy development, and enhanced crop performance throughout the growing season, leading to measurable yield benefits.
These findings suggest that temperature-insensitive microbial activity enables sustained plant growth promotion during critical establishment phases, helping crops overcome early stress and preserve yield potential. The results support microbial temperature resilience as a valuable trait for next-generation biological seed treatments and biostimulants.

Chileans insular biogeographic configuration is bounded by the Pacific Ocean, the Andes Mountains, the Atacama Desert, and the Patagonian Ice Fields—has generated an exceptional concentration of biodiversity and endemism (Arroyo et al., 2006; Luebert & Pliscoff, 2017). This environmental mosaic includes hyper arid deserts, Mediterranean agroecosystems, volcanic soils, temperate rainforests, and subpolar environments, offering a unique natural laboratory for microbial diversification.Within this context, SynergiaBIO/BioTECNOS has implemented an applied research program aimed at developing agricultural bioinputs derived from native microbial isolates. Rizospheric, endophytic, and environmental microorganisms were systematically collected across contrasting Chilean ecosystems. Isolates were challenged in vitro under abiotic stressors simulating drought and salinity and were further screened through enzymatic activity assays associated with plant growth promotion and biocontrol mechanisms. The most promising strains were taxonomically identified using molecular methods, formulated into functional microbial individuals and consortia, and evaluated in greenhouse, nursery, and field trials.The current collection comprises more than 450 strains and approximately 20 experimental formulations. These have demonstrated the capacity to enhance tolerance to drought and salt stress, improve root vigor, promote plant growth, to induce plant defence response and increase crop yields across multiple species. Ongoing efforts focus on production scaling and large scale field validation, advancing toward the development of territorially grounded bioinputs based on Chilean unique microbial biodiversity.

Microbial biofertilizers are central to sustainable agriculture, yet their performance under combined nutrient limitation, alkaline chemistry, low water retention and abiotic stress remains poorly resolved. This study used lunar regolith simulants as chemically constrained substrates to examine whether legume–rhizobium symbiosis can establish biological functionality under extreme low-input conditions.Faba bean (Vicia faba L.) was inoculated with Rhizobium leguminosarum strain WSM1455 and grown for eight weeks in two chemically contrasting lunar regolith simulants, LHS-1 and LMS-1, alongside sandy loam soil. Seeds were exposed before sowing to acute ionizing irradiation at 0, 0.5, 5 or 10 Gy, and substrates were tested under native or gypsum-amended pH. No nitrogen fertilizer was supplied.Water-extractable chemistry, rather than bulk oxide composition, best explained plant and symbiotic performance. LHS-1 released higher soluble K, Mg and P and retained more water than LMS-1, supporting stronger biomass production, higher SPAD chlorophyll index and visible nodulation. Gypsum amendment further improved growth and nodulation in sandy loam and LHS-1, consistent with partial relief of alkaline stress and improved Ca²⁺ availability. In contrast, LMS-1 showed poor baseline growth and no nodulation under any treatment, indicating that adverse substrate chemistry constrained both host development and rhizobial establishment. Irradiation caused dose-dependent reductions in biomass, chlorophyll status, nodule number and post-harvest nitrogen.This work demonstrates that microbial biofertilizer efficacy depends strongly on soluble substrate chemistry and highlights rhizobium-enabled legumes as a promising strategy for building nutrient functionality in chemically constrained cropping systems on Earth and beyond.

Protein hydrolysates are widely used as plant biostimulants and biofertilizers, yet their mechanisms of action remain poorly defined due to the heterogeneous and variable composition of conventional thermal hydrolysates. Here we present the systematic characterisation of a pig bristle hydrolysate produced by enzymatic hydrolysis, and the elucidation of the peptide fraction driving hydrolysate bioactivity. LC-MS/MS proteomic analysis identified 649 peptides, all within the sub-2 kDa molecular weight range, which are derived from structural protein of pig bristles and do not show any sequence similarity with plant or microbial peptides. A defined subset of 18 peptides of tis hydrolysate was selected for individual chemical synthesis and bioactivity validation. Remarkably, these individual peptides show bioactivity (at nanomolar concentrations) on plants root architecture and trigger signalling responses (e.g. rapid cytoplasmic Ca²⁺ burst), and transcriptional reprogramming, further supporting their activity as biostimulant molecules. Of note, the activity of these peptides was found to dependent of either previously characterized signaling receptor kinases and regulatory circuits required for lateral root and root hair initiation and formation.We use rhizotrons and an automatised phenotyping platform to determine the performance of crops treated with a fraction enriched in these bioactive peptides, demonstrating a marked promotion of root hair formation and lateral root development, consistent with transcriptional upregulation of root architecture gene markers. Rhizotron assays in tomato and maize corroborated root growth-promoting effects and improved performance of treated plants under greenhouse conditions. These effects were further validated in field trials. These results provide mechanistic evidence that defined low-molecular-weight peptides from valorised animal by-products can function as specific elicitors (biomimetic peptides) of signalling pathways promoting plants growth, offering a rational basis for designing the next-generation of peptide-based biostimulants.

Plant biostimulants are increasingly expected to deliver reproducible agronomic benefits under field conditions, yet product development still often relies on empirical screening of individual substances rather than coordinated regulation of the rhizosphere system. Here, we present a Rhizobiont-oriented approach for biostimulant development, in which plants, roots, microbial consortia, and soil nutrient processes are treated as an integrated functional unit. This strategy shifts product innovation from single-factor stimulation toward coordinated regulation of the root–soil–microbe interface.
Our framework integrates four functional modules: differential metabolites from superior genotypes as biological targets, low-cost plant-derived active fractions obtained through biomass juice extraction, co-application of IAA-producing and phosphate-solubilizing microbes, and material-based delivery to amplify root-zone microdomain effects. Within this framework, broad claims such as growth promotion or stress tolerance are translated into verifiable processes, including enhanced carbon flow to roots, improved microbial functionality, greater phosphorus mobilization, and higher interface efficiency for root development and stress adaptation. In validation experiments, the combined material–microbe strategy increased biomass by 0.7–2.1 fold, improved nutrient uptake by more than 10%, and significantly optimized root system architecture.
To support pathway identification and design optimization, an AI-assisted workflow was also used for literature screening, information extraction, relationship mining, and knowledge integration. Together, this work provides a practical route for developing greener, lower-cost, and more targeted biostimulants based on Rhizobiont regulation and scenario-oriented validation.

The dominant discovery playbook in biostimulants and biofertilizers has been straightforward: identify a microbe that performs a function, sometimes optimize or engineer it, and deploy the organism broadly across environments. Yet field performance remains inconsistent, products frequently fail to achieve their potential, and reproducibility across cropping systems remains limited. What has the industry missed?Current approaches overlook a fundamental ecological reality: function alone does not determine success. Plant-associated microbes are exquisitely adapted to their habitat through selection and evolution. Soil chemistry, plant hosts, nutrient availability, and especially interactions with other microbes all shape colonization, persistence, and functional performance. Yet surprisingly little is known about how microbes conflict, compete, coexist, communicate, and collaborate within diverse indigenous communities. This creates a mismatch in current screening strategies, which overwhelmingly prioritize individual function while largely ignoring the ecological processes that govern establishment and survival within complex soil and plant microbiomes. Moreover, crop-beneficial functions themselves may impose ecological costs that directly influence microbial fitness, compromising colonization or persistence. Understanding these tradeoffs requires viewing microbial products through the lens of ecology, not function alone.We present data demonstrating that microbial species interactions are central to both microbial fitness and functional success, and that functional performance can sometimes work against colonization and persistence.

One of the major challenges in biostimulant development is the limited understanding of modes of action. Many biostimulants, especially plant-derived products with complex bioactive components, are still developed mainly through empirical screening, making it difficult to predict functional consistency, optimize formulation design, or explain field performance.
This study presents a gene-expression-guided platform, GeneNavXâ„¢, for the targeted and precision development of plant-derived biostimulants. By using the expression patterns of key genes involved in endogenous phytohormone signaling as a navigation tool, the platform connects natural bioactive materials with defined physiological functions, including root development regulated by auxin and cytokinin, abiotic stress tolerance associated with abscisic acid, immune priming mediated by salicylic acid and jasmonic acid, as well as nutrient-use efficiency, yield formation, and quality improvement. Instead of relying only on phenotype-based screening, this approach enables the identification of functional bioactive clusters and supports mechanism-oriented product development.
Several natural-origin active systems, including pollen polysaccharides, L-theanine, and Astragalus polysaccharides, have been developed under this framework. These technologies are protected by multiple patent families, and related biostimulant products have obtained certification under the European Union biostimulant regulatory framework.
The GeneNavXâ„¢ platform integrates molecular response profiling, functional screening, formulation development, and greenhouse and field validation. This creates a development pathway from molecular signals to agronomic performance, helping to improve the reliability and explainability of plant-derived biostimulants under practical field conditions.
Overall, this work demonstrates how gene-expression data can guide the precision development of next-generation biostimulants and support the transition of the industry from empirical selection toward mechanism-based, evidence-driven biological solutions.

Drought stress is one of the major constraints affecting crop productivity worldwide, while the fluctuating costs of conventional fertilisers and the environmental concerns of crop protection products are driving the need for more sustainable agronomic solutions. In this context, plant-based biostimulants are gaining attention for their ability to support plant growth, productivity and resilience under stress conditions. Moringa oleifera is a fast-growing and highly productive plant, naturally rich in bioactive compounds, with promising applications in agriculture. Here, we present a patented Moringa oleifera-based biostimulant (MOB), obtained through an exclusive multi-technological extraction process, specifically designed to deliver a high-performance product. Bioactive fingerprinting revealed a complex composition, including polyphenols, flavonoids, organic acids, amino acid derivatives and lipids, associated with strong antioxidant capacity, nutritional richness and metabolic complexity. In tomato seedlings, MOB application promoted faster germination and increased root length compared to untreated controls. Under greenhouse drought-stress conditions, drench application significantly increased carotenoid content and relative water content, while improving fruit set and fruit cluster weight compared to stressed untreated plants. Foliar application also enhanced plant vegetative status under optimal growing conditions. The potential of MOB to improve tomato resilience under drought stress was confirmed also in field conditions, with a 20% yield increase versus untreated stressed control. Genetic analysis completed these findings, revealing the metabolic rearrangements behind the observed physiological responses and supporting a comprehensive understanding of MOB-driven plant performance improvement.Together, these findings bridge bioactive fingerprinting, genetic evidence and agronomic validation, providing a 360° picture of MOB action.