The study examined leaf pavement cell shape complexity across a natural European aspen (Populus tremula) population, using GWAS to pinpoint the transcription factor MYB305a as a regulator of cell geometry. Functional validation showed that MYB305a expression is induced by drought and contributes to shape simplification, with cell complexity negatively correlated with water-use efficiency and climatic variables of the genotypes' origin.
A field trial of ten grapevine rootstock genotypes grafted to two scion varieties revealed that vine compartment (berry vs. root) primarily determines elemental composition, while rootstock genotype has modest effects. The rhizosphere microbiome was largely conserved across genotypes, but taxa such as Streptomyces and Mesorhizobium showed negative correlations with a mineral profile dominated by molybdenum, cadmium, potassium, and iron, indicating specific microbe‑element associations.
A genome‑wide association study of 187 bread wheat genotypes identified 812 significant loci linked to 25 spectral vegetation indices under rainfed drought conditions, revealing a major QTL hotspot on chromosome 2A that accounts for up to 20% of variance in greenness and pigment traits. Candidate gene analysis at this hotspot uncovered stress‑responsive genes, demonstrating that vegetation indices are heritable digital phenotypes useful for selection and genetic analysis of drought resilience.
The study identified the poplar homolog of Arabidopsis HDG11 and generated transgenic poplar hybrids overexpressing PtaHDG11. Constitutive expression conferred markedly improved drought tolerance, as evidenced by higher leaf water content, reduced oxidative damage, up‑regulation of antioxidant genes, and greater post‑stress biomass, while also causing a glabrous phenotype. These results highlight PtaHDG11 as a promising target for breeding drought‑resilient trees.
The study generated a high-quality, phased diploid reference genome for the grapevine cultivar Pinot noir and combined it with Oxford Nanopore sequencing of 23 clones to map genome-wide genetic and epigenetic variation. While somatic SNPs and structural variants are rare and depleted from coding regions, extensive CG methylation differences were found within gene bodies and accurately recapitulated clonal phylogenies, indicating stable, mitotically inherited epialleles that record propagation history.
The authors performed a genome-wide analysis of 53 CCCH zinc‑finger genes in pearl millet, identified seven stress‑responsive members and demonstrated that overexpressing PgC3H50 in Arabidopsis enhances drought and salt tolerance. They showed that the ABA‑responsive transcription factor PgAREB1 directly binds the PgC3H50 promoter, activating its expression, as confirmed by yeast one‑hybrid, dual‑luciferase and EMSA assays, defining a new PgAREB1‑PgC3H50 regulatory module.
Chromosome-scale Solanum pennellii and Solanum cheesmaniae genome assemblies reveal structural variants, repeat content and recombination barriers of the tomato clade
Authors: van Rengs, W., Fuentes, R. R., Zangishei, Z., Primetis, E., Wang, Y., Fernandes, J., Susanto, T., Lian, Q., Effgen, S., Huettel, B., Alseekh, S., Usadel, B., Underwood, C. J.
The study generated chromosome‑scale de novo assemblies for two wild tomato relatives, Solanum pennellii and Solanum cheesmaniae, using PacBio HiFi, Oxford Nanopore ultra‑long reads, and Hi‑C scaffolding, achieving >99% completeness. Comparative analysis with nine Lycopersicon clade genomes revealed species‑specific structural variants and independent Tekay retrotransposon expansions, while recombination mapping in 709 backcross hybrids demonstrated higher female crossover rates and identified gender‑biased recombination regions and coldspots associated with large structural differences.
Investigating the intraspecific diversity of Vitis vinifera responses to esca with a physiopathology approach
Authors: Gastou, P., Morin, A., Ferrer, N., Alazet, L., Burlett, R., Delzon, S., Lens, F., Moretti, S., Rouveyrol, C., Petriacq, P., Svahn, I., Delmas, C. E. L.
A common garden study of 46 Vitis vinifera cultivars revealed that cultivar-specific water-use traits, rather than xylem anatomy, predict susceptibility to esca disease. Symptomatic vines showed reduced leaf gas exchange, starch storage, and theoretical hydraulic conductivity, while highly susceptible genotypes accumulated more glycosylated flavonoids and terpenes, suggesting a role for xylem‑transported defence metabolites in disease onset.
The study reveals that red pigmentation in quinoa (Chenopodium quinoa) epidermal bladder cells is due to a ~4‑kb genomic insertion that restores the full-length CYP76AD gene, which is the rate‑limiting enzyme for betacyanin synthesis. Cell‑type‑specific RNA‑sequencing showed that this restored CYP76AD is highly upregulated in red bladder cells, and subgenome analysis indicated B‑subgenome dominance for this gene in pigmented tissues.
Using a forward genetic screen of 284 Arabidopsis thaliana accessions, the study identified extensive natural variation in root endodermal suberin and pinpointed the previously unknown gene SUBER GENE1 (SBG1) as a key regulator. GWAS and protein interaction analyses revealed that SBG1 controls suberin deposition by binding type‑one protein phosphatases (TOPPs), with disruption of this interaction or TOPP loss‑of‑function altering suberin levels, linking the pathway to ABA signaling.