The genetic architecture of leaf vein density traits and its importance for photosynthesis in maize
Authors: Coyac-Rodriguez, J. L., Perez-Limon, S., Hernandez-Jaimes, E., Hernandez-Coronado, M., Camo-Escobar, D., Alonso-Nieves, A. L., Ortega-Estrada, M. d. J., Gomez-Capetillo, N., Sawers, R. J., Ortiz-Ramirez, C. H.
Using diverse Mexican maize varieties and a MAGIC population, the study demonstrated that leaf vein density is both variable and plastic, correlating positively with photosynthetic rates for small intermediate veins and increasing under heat in drought-adapted lines. Twelve QTLs linked to vein patterning were identified, highlighting candidate genes for intermediate vein development and shedding light on the evolution of high-efficiency C4 leaf architecture.
The study evaluated how stomatal anatomy and physiological efficiency influence wheat heat tolerance across multi‑environment field trials with 200 genotypes, using early versus delayed sowing to impose temperature stress. Findings revealed a decoupling between anatomical capacity (gsmax) and actual conductance (gs, gse) under heat, plastic shifts toward smaller, denser stomata, and identified 125 QTL linked to stomatal traits, suggesting targets for breeding climate‑resilient wheat.
The authors used a bottom‑up thermodynamic modelling framework to investigate how plants decode calcium signals, starting from Ca2+ binding to EF‑hand proteins and extending to higher‑order decoding modules. They identified six universal Ca2+-decoding modules that can explain variations in calcium sensitivity among kinases and provide a theoretical basis for interpreting calcium signal amplitude and frequency in plant cells.
Four barley genotypes were examined under simultaneous Fusarium culmorum infection and drought, revealing genotype-dependent Fusarium Head Blight severity and largely additive transcriptomic responses dominated by drought. Co‑expression and hormone profiling linked ABA and auxin to stress‑specific gene modules, and a multiple linear regression model accurately predicted combined‑stress gene expression from single‑stress data, suggesting modular regulation.
The study examined nitrogen use strategies in the model alga Chlamydomonas reinhardtii by comparing growth on ammonium, nitrate, and urea, finding similar molar nitrogen utilization efficiency under saturating conditions. Rapid nitrogen uptake and storage were demonstrated through pulse experiments, and source‑specific transcriptome analysis revealed distinct regulation of assimilation pathways and transporters, supporting a model of flexible nitrogen acquisition and storage.
Characterization of a dominant SmNac-like gene as a candidate for photosensitivity in the fruit peel of eggplant
Authors: Gomis-Cebolla, J., Manrique, S., Arrones, A., Toledo-Tolgar, M. D., Luna, J., Baraja-Fonseca, V., Sanchez-Pascual, J., Gimeno-Paez, E., Plazas, M., Gramazio, P., Vilanova, S., Prohens, J.
The study identified that fruit photosensitivity in eggplant is governed by a single dominant gene, with QTLs clustering at the distal end of chromosome 10 (84.1-87.9 Mb). Bulked segregant analysis sequencing and RNA‑seq highlighted the SmNAC1‑like transcription factor as a likely regulator of anthocyanin accumulation, though no coding sequence mutations were detected, suggesting regulatory control at another level.
The study investigates how maternal environmental conditions, specifically temperature and light intensity, influence seed longevity in eight Arabidopsis thaliana natural accessions. Seeds developed under higher temperature (27 °C) and high light showed increased longevity, with transcriptome analysis of the Bor-4 accession revealing dynamic changes in stored mRNAs, including upregulation of antioxidant defenses and raffinose family oligosaccharides. These findings highlight the genotype‑dependent modulation of seed traits by the maternal environment.
Novel substrate affinity of FaCCR1 and FaCCR1/FaOCT4 expression control the content of medium-chain esters in strawberry fruit
Authors: Roldan-Guerra, F. J., Amorim-Silva, V., Jimenez, J., Mari-Albert, A., Torreblanca, R., Ruiz del Rio, J., Botella, M. A., Granell, A., Sanchez-Sevilla, J. F., Castillejo, C., Amaya, I.
The study identified a major QTL on chromosome 6A that accounts for 40% of variation in medium-chain ester (MCE) levels in strawberry fruit, pinpointing FaCCR1 and FaOCT4 as the causal genes. Functional validation through subcellular localization, transient overexpression, enzymatic assays, and molecular docking demonstrated that FaCCR1 also catalyzes MCE precursor reactions, and a KASP marker in FaOCT4 was developed for breeding fragrant cultivars.
The study genotyped 1,013 hard red spring wheat lines using SNP arrays and targeted KASP markers to track changes in genetic diversity and the distribution of dwarfing Rht alleles over a century of North American breeding. It found shifts from Rht‑D1b to Rht‑B1b dominance, identified low‑frequency dwarf alleles at Rht24 and Rht25 that have increased recently, and revealed gene interactions that can fine‑tune plant height, along with evidence of recent selection for photoperiod sensitivity.
The study identified seven adult plant resistance QTL for oat crown rust using two recombinant inbred line populations, with a major QTL (QPc_GS7_4A.2) on chromosome 4A closely linked to the Pc61 resistance gene. KASP markers targeting SNPs tightly linked to the four most significant QTL were developed, and genetic and haplotype analyses confirmed the association of QPc_GS7_4A.2 with both seedling and adult plant resistance, providing valuable tools for oat breeding.