Identification of a novel link connecting indole-3-acetamide with abscisic acid biosynthesis and signaling
Authors: Moya-Cuevas, J., Ortiz-Garcia, P., Gonzalez Ortega-Villizan, A., Viguera-Leza, I., Perez-Gonzalez, A., Paz-Ares, J., Alonso-Blanco, C., Vicente-Carbajosa, J., Pollmann, S.
A genome-wide association study of 166 Iberian Arabidopsis accessions identified loci, including ABA3 and GA2ox2, that modulate the inhibitory effect of the auxin precursor indole-3-acetamide (IAM) on primary root elongation. Integrating sequence analysis, transcriptomics, 3D protein modeling, and mutant physiology revealed that IAM promotes ABA biosynthesis and signaling, uncovering a novel node of hormone crosstalk.
The study demonstrates that the root endophytic fungus Colletotrichum tofieldiae promotes growth of various plant species under nitrogen-deficient conditions, a process that depends on Arabidopsis thaliana nitrate transporters and the fungal N‑utilization regulator CtAREA. Isotopic 15N tracing shows that the fungus transfers nitrogen to the host via a CtAREA-dependent but transporter‑independent pathway, while the associated bacterium Paraburkholderia monticola further enhances growth and suppresses fungal pathogenicity in certain host mutants.
Whole genome sequencing-based multi-locus association mapping for kernel iron, zinc and protein content in groundnut
Authors: Sagar, U. N., Parmar, S., Gangurde, S. S., Sharma, V., Pandey, A. K., Mohinuddin, D. K., Dube, N., Bhat, R. S., John, K., Sreevalli, M. D., Rani, P. S., Singh, K., Varshney, R. K., Pandey, M. K.
The study used multi‑season phenotyping for iron, zinc, and protein content together with whole‑genome re‑sequencing of a groundnut mini‑core collection to conduct a genome‑wide association study, identifying numerous marker‑trait associations and candidate genes linked to nutrient homeostasis. SNP‑based KASP markers were designed for nine loci, of which three showed polymorphism and are ready for deployment in genomics‑assisted breeding for nutrient‑rich groundnut varieties.
The study integrates genome, transcriptome, and chromatin accessibility data from 380 soybean accessions to dissect the genetic and regulatory basis of symbiotic nitrogen fixation (SNF). Using GWAS, TWAS, eQTL mapping, and ATAC-seq, the authors identify key loci, co‑expression modules, and regulatory elements, and validate the circadian clock gene GmLHY1b as a negative regulator of nodulation via CRISPR and CUT&Tag. These resources illuminate SNF networks and provide a foundation for soybean improvement.
The study generated a phenotypic dataset for 550 Lactuca accessions, including 20 wild relatives, and applied an iterative two‑step GWAS using a jointly processed SNP set for cultivated lettuce (L. sativa) and its wild progenitor (L. serriola) to dissect trait loci. Known and novel QTLs for anthocyanin accumulation, leaf morphology, and pathogen resistance were identified, with several L. serriola‑specific QTLs revealing unique genetic architectures, underscoring the breeding value of wild lettuce species.
The study used chlorophyll fluorescence imaging to map non-photochemical quenching (NPQ) gradients along barley leaf axes and found heat stress attenuates NPQ induction, revealing spatial heterogeneity in stress responses. Genome‑wide association and transcriptomic analyses identified candidate genes, notably HORVU.MOREX.r3.3HG0262630, that mediate region‑specific heat responses, highlighting pathways for improving cereal heat resilience.
The study profiled root transcriptomes of Arabidopsis wild type and etr1 gain-of-function (etr1-3) and loss-of-function (etr1-7) mutants under ethylene or ACC treatment, identifying 4,522 ethylene‑responsive transcripts, including 553 that depend on ETR1 activity. ETR1‑dependent genes encompassed ethylene biosynthesis enzymes (ACO2, ACO3) and transcription factors, whose expression was further examined in an ein3eil1 background, revealing that both ETR1 and EIN3/EIL1 pathways regulate parts of the network controlling root hair proliferation and lateral root formation.
The study applied Spatial Analysis of Field Trials with Splines (SpATS) and Neighbor Genome-Wide Association Study (Neighbor GWAS) to barley field data, revealing that neighboring genotypes contribute to spatial variation in disease damage. Neighbor GWAS identified variants on chromosome 7H that modestly affect net form net blotch and scald resistance, suggesting that genotype mixtures could mitigate pest damage.
The study evaluated natural genetic variation in non-photochemical quenching and photoprotection across 861 sorghum accessions grown in the field over two years, revealing moderate to high broad-sense heritability for chlorophyll fluorescence traits. By integrating genome-wide association studies (GWAS) with transcriptome-wide association studies (TWAS) and covariance analyses, the authors identified 110 high-confidence candidate genes underlying photoprotection, highlighting a complex, polygenic architecture for these traits.
The study examined how white lupin (Lupinus albus) cotyledons mobilize nitrogen and minerals during early seedling growth under nitrogen‑deficient conditions, revealing that 60 % of stored proteins degrade within eight days and are redirected to support development. Proteomic analyses showed dynamic shifts in nutrient transport, amino acid metabolism, and stress responses, and premature cotyledon removal markedly impaired growth, highlighting the cotyledon's essential role in nutrient supply and transient photosynthetic activity.