Climate change is degrading arable soils and imposing chronic abiotic stress on plants. As the primary interface with the soil, the root system is especially vulnerable, and plants respond by remodelling their root system architecture (RSA). Most studies have examined single stresses in isolation and so fail to capture the multifactorial environments in which plants actually grow. Rising salinity impairs development by compromising cellular integrity and triggering cytotoxic responses, and it simultaneously restricts uptake of phosphorus, a macronutrient required for nucleic acid and protein synthesis. Combined stresses can amplify these effects, yet how plants adjust RSA to cope with them remains poorly understood. Here we performed a meta-analysis of public transcriptomic datasets for salinity and phosphate deficiency in Arabidopsis thaliana. Integrating these data with protein-protein interaction modelling and DNA-binding (DAP-seq) analyses, we identified two basic leucine zipper transcription factors, ABF2 and bZIP2, as candidate integrators of the combined-stress response. Characterization of abf2, bzip2 and double mutants revealed RSA alterations and allowed us to identify downstream targets of each factor. Our findings offer new insight into root adaptation under combined stress and represent one of the few comprehensive analyses of how multiple abiotic stressors jointly shape root development and plant fitness. Highlight Data mining of public transcriptomes, network inference and AlphaFold-Multimer screening identify ABF2 and bZIP2 as interacting regulators of root remodelling under combined stress.
H. Salinas-Grenet, N. Johnson, M. A. Ibeas et al.· bioRxiv· 0 citations
Plants establish intimate associations with rhizosphere microorganisms that profoundly influence their growth, development, and stress resilience. Among these, plant-growth-promoting rhizobacteria (PGPR) enhance nutrient acquisition, modulate phytohormone homeostasis and reshape root system architecture, thereby improving plant fitness. Despite extensive evidence supporting their beneficial effects, the molecular and cellular mechanisms underlying microbe-driven modulation of specific root traits remain incompletely understood. Through extensive phenotypic investigation, we established that Pseudomonas sp. M25, a previously described PGPR strain, produces a significant increase in leaf relative water content and evapotranspiration of Arabidopsis thaliana without impacting on rosette growth or photosynthetic parameters. Inoculation with M25 leads to enhanced drought tolerance, and this is associated not with changes in root architecture but with a marked increase in root hair (RH) abundance and length. The stimulation of RH development by this Pseudomonas strain is based on the genetic requirement for RH-related basic helix-loop-helix family transcription factors, including ROOT HAIR DEFECTIVE 6 (RHD6) and RHD6-LIKE 1 (RSL1), which regulate RH development via RHD6-LIKE 4 (RSL4) and RHD6-LIKE 2 (RSL2). Pseudomonas sp. M25 can partially circumvent the lack of RHD6 but requires RSL1 and the downstream transcription factors RSL2 and RSL4 to induce RH growth. These findings indicate that this bacterium can circumvent RHD6 to activate RSL4, which subsequently promotes RH growth. Our investigation identifies some essential signaling components regulated by Pseudomonas sp. M25 to optimize RH responses.
Victoria Berdion Gabarain, Ignacio Llamedo, P. D. Cáceres et al.· Plant physiology and biochem...· 0 citations
The findings uncover a pathway that regulates RH growth as part of a broader, microorganism-dependent root system architecture plasticity under low-water conditions and highlight the potential of uncovering plant–microorganism mechanisms to strengthen crop resilience in a changing climate.
A. Rahimi, Sofia Stiegert, Omid Karami et al.· Nature Plants· 1 citation
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
