A transcriptomic dataset of supplemental red-light effects on solid-stem development in two spring wheat varieties.

Wheat stem sawfly (WSS) (Cephus cinctus Norton) is a major pest of hard red spring wheat, causing significant yield losses. Genetic resistance conferred by solid stem wheat genotypes remains the most effective strategy for mitigating WSS damage. However, pith development, a key determinant of stem solidness and resistance, exhibits considerable variation among genotypes and is strongly influenced by environmental factors, particularly light quality. This study addresses the gap in understanding how light regulated molecular pathways contribute to stable and uniform pith expression. To elucidate these mechanisms, two contrasting spring wheat varieties, Duclair (solid-stemmed) and Reeder (hollow-stemmed), were grown under standard greenhouse lighting (GL) and supplemental red-light (SL) treatments. We performed comprehensive transcriptomic profiling to identify light-responsive and genotype-specific changes in gene expression. Differential expression, Gene Ontology, and KEGG enrichment analyses revealed that supplemental red light significantly modulates transcriptional pathways associated with phytochrome signalling, pith parenchyma differentiation, secondary cell wall modification, and programmed cell death processes tightly linked to pith formation. These findings provide a molecular framework for understanding how enhanced red light promotes uniform pith development in solid-stemmed wheat. By clarifying the biological pathways underlying light-modulated stem solidity, this dataset supports breeding and biotechnological strategies to improve resistance to the wheat stem sawfly. This dataset identified approximately 12,041 differentially expressed genes, with 8007 upregulated, and 4034 downregulated in Duclair SL, compared to Reeder SL. Strengthening this resistance has direct implications for reducing lodging, yield loss, and economic damage associated with WSS infestation.