Yobi, A. | bioRxiv Science

bioRxiv2026

From Kernel to Kitchen: Asparagine Synthetase 3 is Involved in Free Asparagine Accumulation in Maize Kernels

Acrylamide is a probable dietary carcinogen formed through high-temperature cooking processes from one of its precursors, free asparagine (Asn). To reduce acrylamide formation potential in maize-based food products, the genetic basis for the accumulation of free Asn in maize kernels must be elucidated. In this study we integrated complementary quantitative genetic approaches including quantitative trait locus (QTL) mapping of a biparental population and genome-wide association studies (GWAS) in a diverse inbred panel. We ultimately identified one major QTL for free Asn which was not reflected in the GWAS results. Subsequent sequence analysis of the QTL mapping population parents revealed a 921bp deletion in As-paragine Synthetase 3 (ASN3) in the low Asn parent. Validation is underway with rtPCR, genotyping the association panel for the deletion, and evaluation of a CRISPR-Cas9 knockout of ASN3. This work provides a foundation for breeding and genome-editing strategies to reduce acrylamide-forming potential in maize-based foods.

Plant Biology↗

bioRxiv2026

A transcriptomic atlas of grass senescence reveals divergent underground sink networks limit nitrogen recycling in annuals

Senescence enables plants to remobilize and recycle nutrients from aging organs to support growth, reproduction, and survival. In annual crops like maize, nitrogen remobilization from leaves to grain is incomplete, with 30-50% of nitrogen stranded in aboveground tissues and subject to environmental loss. Mitigating nitrogen loss in annual crops could be achieved by leveraging the physiological strategies of perennial grasses, which remobilize nitrogen and other nutrients into underground organs at the end of the growing season, thereby preventing environmental leakage. To uncover the molecular basis of perennial nitrogen recycling to underground organs, we built a transcriptomic atlas from field-grown plants, comprising 2,685 RNA-seq libraries from 14 grass species within the Panicoideae (Poaceae), utilizing maize and sorghum as annual references for comparative analyses. The atlas spans leaves, roots, stalks, and rhizomes across two seasons, from mid-growing season to senescence. Using a photosynthetic index to align the leafs transition from nitrogen sink to source across species, co-expression network analysis revealed that the subnetworks driving leaf nitrogen recycling are preserved across annuals and perennials. However, we discovered that the subnetworks associated with underground sink establishment, specifically those associated with seed-like dormancy and desiccation tolerance pathways, have diverged among annual crop accessions. Our work identifies conserved gene candidates and networks that could be used to reintroduce perennial-like nutrient recycling into annual crops to enhance long-term nutrient retention in the field.

plant biology↗