Genetius

The study evaluates hyperspectral reflectance data to predict 25 anatomical, gas exchange, and chlorophyll fluorescence traits in a maize multi-parent recombinant inbred population across three seasons, using various machine‑learning models. It assesses model performance for unseen genotypes, seasons, and combined scenarios, and examines the impact of data aggregation within a rigorous nested cross‑validation framework. The findings highlight trait‑specific limits to model generalizability and provide a robust protocol for applying hyperspectral phenotyping in breeding programs.

The study identifies fungal effectors from Ustilago maydis that interact with the plant TOPLESS corepressor and trigger gall formation in maize by hijacking auxin‑responsive pathways and lateral root initiation programs. Class II effectors derepress the AtARF7/AtARF19 branch, leading to LBD transcription factor up‑regulation and pluripotent callus development, and mutants in maize LBD genes show reduced gall formation.

The study evaluated a stain-based visual scoring system for quantifying pericarp retention during nixtamalization of maize kernels and compared it to direct pericarp mass measurements, finding moderate correlations (r=0.77 and r=0.56). It identified initial pericarp quantity and ground kernel ash content as the strongest predictors of retention, suggesting these traits are key determinants for improving masa quality. The authors conclude that staining lacks sufficient resolution for precise quantification, highlighting the need for refined phenotyping approaches.

The study identifies two new EMS‑induced missense alleles of the maize opaque1 (o1) gene, o1‑2995 and o1‑tan62, which produce O1 protein yet cause more severe phenotypes than loss‑of‑function alleles, including reduced internode elongation and abnormal subsidiary cell division. These alleles also partially suppress the excessive tassel and ear branching of ramosa mutants, revealing O1’s critical role in internode growth, leaf patterning, inflorescence development, and overall plant architecture.

Metagenomic pool sequencing of infected maize leaves revealed a temporal shift in Exserohilum turcicum populations, with tropical Kenyan clonal lineages becoming predominant in Swiss fields by 2021-2022. This cost‑effective, spatially resolved approach highlighted changes in pathogen epidemiology and consistent phyllobiome composition across landrace and hybrid varieties, informing durable resistance breeding.

The study evaluated whether integrating genetic architecture information from GWAS into simulations improves alignment between simulated and empirical trait data in maize hybrids derived from 333 recombinant inbred lines across multiple environments. Using ≥200 top GWAS hits as causal variants and reducing estimated marker effect sizes increased correlations (0.397‑0.915) and accurately reproduced variance components and genomic prediction performance. This provides a pipeline for realistic digital breeding simulations.

The study co‑expressed BABY BOOM and WUSCHEL2 in Zea mays embryos to induce somatic embryogenesis and used single‑cell analysis to map cell‑type‑specific regulons. This approach identified four novel transcription factors (bHLH48, EREB152, GRF4, HB77) that enhance maize transformation efficiency and produce fertile transgenic plants.

The study examined how heat stress alters the protein and lipid makeup of plastoglobules and thylakoids in the B73 maize inbred line, revealing increased plastoglobule size, number, and adjacent lipid droplets over time. Key changes included elevated triacylglycerol, plastoquinone derivatives, and specific proteins such as Fibrillin 1a/2, indicating a protective role in membrane remodeling and oxidative defense, and suggesting targets for enhancing heat resilience in maize.

The study elucidates a two‑step processing pathway for the maize‑specific phytocytokine Zip1, revealing that its precursor PROZIP1 is first cleaved in the endoplasmic reticulum and cytoplasm by the metacaspase ZmMC9 before the C‑terminal fragment is secreted via an unconventional EXPO‑mediated route. Once in the apoplast, PLCPs CP1 and CP2 further cleave PROZIP1 to release and subsequently degrade the active Zip1 peptide, linking intracellular and extracellular proteolysis to immune signaling.

The authors quantified de novo maize Mutator (Mu) transposon insertions down to a detection limit of 1 in 16,000, showing highly reproducible allele‑frequency distributions within a given tissue but distinct patterns across tissues (e.g., few high‑frequency insertions in roots versus many low‑frequency insertions in endosperm). By re‑examining pollen allele frequencies, they attribute previously reported late‑Mu activity to cell‑division dynamics, offering new insight into how mutation abundance varies during plant development.