Ethylene and ROS Signaling Are Key Regulators of Lateral Root Development under Salt Stress in Tomato
Authors: Rahmati Ishka, M., Zhao, J., Sussman, H., Mohanty, D., Craft, E., Yu, L., Pineros, M., Tester, M., Kawa, D., Mittler, R., Nelson, A., Fei, Z., Julkowska, M. M.
The study examined salt-induced alterations in root system architecture across a diverse panel of wild and cultivated tomato accessions, identifying tolerant varieties with distinct lateral root strategies. By combining Bulk Segregant Analysis of an F2 population with GWAS, the authors pinpointed 22 candidate genes, further narrowing to two key regulators through RNA‑Seq and functional assays involving ethylene and ROS profiling. These findings reveal genetic targets for improving salt resilience in tomato root development.
The study compared physiological, ion‑balance, and metabolic responses of two maize inbred lines—salt‑sensitive C68 and salt‑tolerant NC326—under salinity stress. Untargeted metabolomics identified 56 metabolites and, together with genetic analysis, linked 10 candidate genes to key protective metabolites, revealing constitutive and inducible mechanisms of salt tolerance.
The study models maize flowering time plasticity using a physiological reaction norm derived from multi-environment trial data, revealing genotype-specific differences in temperature-driven development and photoperiod perception. It introduces an envirotyping metric that shows genotypes can experience markedly different photoperiods even within the same environment, and demonstrates distinct adaptive strategies between tropical and temperate germplasm.
The study generated a temporal physiological and metabolomic map of leaf senescence in diverse maize inbred lines differing in stay‑green phenotype, identifying 84 metabolites associated with senescence and distinct metabolic signatures between stay‑green and non‑stay‑green lines. Integration of metabolite data with genomic information uncovered 56 candidate genes, and reverse‑genetic validation in maize and Arabidopsis demonstrated conserved roles for phenylpropanoids such as naringenin chalcone and eriodictyol in regulating senescence.
The study examined how genetic variation among 181 wheat (Triticum aestivum) lines influences root endophytic fungal communities using ITS2 metabarcoding. Heritability estimates and GWAS identified 11 QTLs linked to fungal clade composition, highlighting genetic control of mycobiota, especially for biotrophic AMF. These findings suggest breeding can be used to modulate beneficial root-fungal associations.
The study surveyed vegetative water use and life‑history traits across Arabidopsis thaliana ecotypes in both controlled and outdoor environments to assess how climatic history shapes water‑use strategies. Trait‑climate correlations and genome‑wide association analyses uncovered that ecotypes from warmer regions exhibit higher water use, and identified MYB59 as a key gene whose temperature‑linked alleles affect water consumption, a finding validated using myb59 mutants. These results indicate that temperature‑driven adaptive differentiation partly explains intraspecific water‑use variation.
Genetic control of the leaf ionome in pearl millet and correlation with root and agromorphological traits
Authors: Nakombo-Gbassault, P., Arenas, S., Affortit, P., Faye, A., Flis, P., Sine, B., Moukouanga, D., Gantet, P., Kosh Komba, E., Kane, N., Bennett, M., Wells, D., Cubry, P., Bailey, E., Vigouroux, Y., Grondin, A., Laplaze, L.
The study performed ionomic profiling and genome-wide association studies on a diverse panel of pearl millet infield across two seasons to uncover genetic factors controlling nutrient acquisition. Soil analyses revealed stable depth-dependent patterns for phosphorus and zinc, while leaf ion concentrations showed high heritability and associations with root and agronomic traits. Integrating GWAS with gene expression data identified candidate ion transport/homeostasis genes for breeding nutrient-efficient, climate-resilient millet.