Phosphite (Phi) and phosphate (Pi) share the same root uptake system, but Phi acts as a biostimulant that modulates plant growth and disease resistance in a species‑ and Pi‑dependent manner. In Arabidopsis, Phi induces hypersensitive‑like cell death and enhances resistance to Plectosphaerella cucumerina, while in rice it counteracts Pi‑induced susceptibility to Magnaporthe oryzae and Fusarium fujikuroi, accompanied by extensive transcriptional reprogramming.
The study employed ultra large‑scale 2D clinostats to grow tomato (Solanum lycopersicum) plants beyond the seedling stage under simulated microgravity and upright control conditions across five sequential trials. Simulated microgravity consistently affected plant growth, but the magnitude and direction of the response varied among trials, with temperature identified as a significant co‑variant; moderate heat stress surprisingly enhanced growth under simulated microgravity. These results highlight the utility of large‑scale clinostats for dissecting interactions between environmental factors and simulated microgravity in plant development.
Quantitative trait locus mapping of root exudate metabolome in a Solanum lycopersicum Moneymaker x S. pimpinellifolium RIL population and their putative links to rhizosphere microbiome
Authors: Kim, B., Kramer, G., Leite, M. F. A., Snoek, B. L., Zancarini, A., Bouwmeester, H.
The study used untargeted metabolomics and QTL mapping in a tomato recombinant inbred line population to characterize root exudate composition and identify genetic loci controlling specific metabolites. It reveals domestication-driven changes in exudate profiles and links metabolic QTLs with previously reported microbial QTLs, suggesting a genetic basis for shaping the root microbiome.
Root growth promotion by Penicillium melinii: mechanistic insights and agricultural applications
Authors: Gutierrez-Manso, L., Devesa-Aranguren, I., Conesa, C. M., Monteoliva-Garcia, G., Gonzalez-Sayer, S., Lozano-Enguita, A., Blasio, F., Ugena, L., Nolasco, J., Vazquez-Mora, A., Levy, C. C. B., Ariel Otero, E., Fernandez-Calvo, P., Moreno-Risueno, M. A., petrik, I., Pencik, A., Reguera, M., Gonzalez-Bodi, S., Huerta-Cepas, J., Sacristan, S., del Pozo, J. C., Cabrera, J.
The study characterizes the endophytic fungus Penicillium melinii, isolated from Arabidopsis thaliana roots, as a plant‑growth‑promoting agent that enhances root architecture and biomass across Arabidopsis, quinoa, and tomato. Integrated phenotypic, transcriptomic, and hormonal analyses reveal that the fungus stimulates auxin‑related pathways and modest stress responses, leading to increased tomato yield in field trials, underscoring its value as a model for root development and a sustainable biostimulant.
Semi-automated image analysis of root architecture and early root development in faba bean and white clover and genomic estimation of breeding values and correlations
Authors: Nagy, I., Kristensen, P. S., Malinowska, M., Nielsen, L. K., Schiemann, A., Rolund, N., Andersen, S. U., Asp, T.
The study evaluated early root development of faba bean and white clover genotypes using greenhouse rhizobox experiments and a semi‑automated image‑based root phenotyping pipeline. It proposes a workflow linking root traits to multivariate genetic models for genomic estimation of breeding values and ties greenhouse observations to field yield performance, aiming to accelerate breeding of climate‑resilient protein crops for Northern Europe.
Compartmentalized above- and belowground defenses in Tanacetum vulgare are tailored to localized antagonists
Authors: Newrzella, H., Heinen, R., Villasante, C. M., Zimmer, I., Weber, B., Kary, P., Gerl, G., Neuhaus, A., Sigalas, A., Ojeda-Prieto, L., Winkler, J. B., Weisser, W., Schnitzler, J.-P.
Using high‑throughput root phenotyping and targeted terpenoid profiling, the study examined three leaf chemotypes of Tanacetum vulgare and their responses to wireworm (Agriotes spp.) and aphid (Macrosiphoniella tanacetaria) herbivory. Wireworms induced large increases in root sesquiterpenoids in two chemotypes, while aphids boosted leaf monoterpenoid emissions only in chemotype 1, revealing chemotype‑specific, compartmentalized defense strategies linked to distinct root system architectures.
Evaluation of combined root exudate and rhizosphere microbiota sampling approaches to elucidate plant-soil-microbe interaction
Authors: Escudero-Martinez, C., Browne, E. Y., Schwalm, H., Santangeli, M., Brown, M., Brown, L., Roberts, D. M., Duff, A. M., Morris, J., Hedley, P. E., Thorpe, P., Abbott, J. C., Brennan, F., Bulgarelli, D., George, T. S., Oburger, E.
The study benchmarked several sampling approaches for simultaneous profiling of root exudates and rhizosphere microbiota in soil-grown barley, revealing consistent exudate chemistry across methods but variation in root morphology and nitrogen exudation. High‑throughput amplicon sequencing and quantitative PCR showed protocol‑specific impacts on microbial composition, yet most rhizosphere-enriched microbes were captured by all approaches. The authors conclude that different protocols provide comparable integrated data, though methodological differences must be aligned with experimental objectives.
The study investigated metabolic responses of kale (Brassica oleracea) grown under simulated microgravity using a 2-D clinostat versus normal gravity conditions. LC‑MS data were analyzed with multivariate tools such as PCA and volcano plots to identify gravity‑related metabolic adaptations and potential molecular markers for spaceflight crop health.
The study investigates how volatile organic compounds (VOCs) emitted by the fungi Laccaria bicolor, Hebeloma cylindrosporum, and Serendipita indica affect root architecture and meristem regulation in Arabidopsis thaliana and Populus tremuloides. Results show that these fungal VOCs alter root morphology in both species and modulate the expression of the stem‑cell regulator WOX5, highlighting a role for VOC‑mediated signaling in maintaining root meristem homeostasis.
The study combined ecometabolomics of root exudates with fungal community profiling to assess how abiotic (soil moisture, temperature legacy) and biotic (microbial inoculum, plant density) treatments shape metabolite diversity and fungal assemblages in Guarea guidonia seedlings. While soil microbial legacy and moisture drove metabolite diversity, antimicrobial treatments altered metabolite composition, and fungal community structure was linked to metabolite profiles, revealing metabolite‑fungal associations as early indicators of plant response to disturbance.