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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #429083
Research Project: Developing Strategies and Tools to Mitigate Biotic and Abiotic Stresses in Cotton and Managing the National Cotton Variety Testing Program

Location: Crop Genetics Research

Title: Supplemental red-light improves consistency of solid stem phenotype in solid stem wheat varieties

Author
item Mendu, Lavanya
item BATHINI, AKSHARA - Montana State University
item SINGH, NAGENDRA - Texas A&M University, Kingsville
item MENDU, VENUGOPAL - Texas A&M University, Kingsville

Submitted to: Plant Stress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2026
Publication Date: 7/10/2026
Citation: Mendu, L., Bathini, A., Singh, N., Mendu, V. 2026. Supplemental red-light improves consistency of solid stem phenotype in solid stem wheat varieties. Plant Stress. 22:1-15. https://doi.org/10.1016/j.stress.2026.101475.
DOI: https://doi.org/10.1016/j.stress.2026.101475

Interpretive Summary: Wheat stem sawfly (WSS) is a devastating pest in Montana, leading to grain yield loss and reduction in grain protein content. Therefore, investigating ways to control this pest is critical. Although enormous efforts were devoted to control this pest, only genetic resistant varieties known as solid stem variety were identified. The solid stem varieties were used as the only management option for mitigating WSS. However, they do not provide complete resistance due to the leaky solid stem phenotype (solid stem characteristic is not stable throughout the plant). We discovered that light is regulating the solid stem phenotype, and red light supplementation (SL) has improved solid stem in main stem internodes and all tiller internodes. A greenhouse experiment was conducted using spring wheat varieties Choteau, Duclair, Dagmar, Conan, Fortuna, Vida, and Reeder. Results showed that SL treatment induced uniform plant development in Duclair, Dagmar and Choteau. Studying the genes involved in the responses of these wheat cultivars to SL revealed that these genes are involved in cell division, growth and development of plants, and consequently will impact the wheat yield. This knowledge is important for wheat breeders to select for wheat varieties against the pest. Identification of these genes and inducing their products will increase the resistance of the solid stem wheat varieties, reducing wheat loss, contributing to growers economic profit.

Technical Abstract: Wheat stem sawfly (WSS) is a major pest with limited control options, which leads to grain yield loss and reduction in grain protein content. Therefore, investigating genetic ways to control this pest is critical. Genetic resistance, mediated by solid-stem genotypes, was preferred for the management of WSS for the past six to seven decades. Currently available solid stem varieties exhibit inconsistent solid stem phenotypes. Increased light intensity and longer day length result in higher solid stem expression and vice versa. To investigate the effect of red light on solid stem development, a greenhouse study was conducted under supplemental red light (SL) conditions using seven spring wheat varieties (Choteau, Conan, Dagmar, Duclair, Fortuna, Vida, along with Reeder, a hollow stem variety). The results showed that SL treatment improved solid stem phenotypes in solid stem varieties. Duclair, Dagmar, and Choteau exhibit consistent pith expression throughout the plant. Overall, this study demonstrated that supplemented red-light treatment resulted in uniform pith development throughout the plant, including main stem and tiller internodes. Transcriptomic analysis of Reeder and Duclair's first internode under SL and control greenhouse (GL) conditions identified 55,997 differentially expressed genes (DEGs), with SL upregulating genes linked to cell division, phytochrome signaling, and photosynthesis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichments highlighted pathways for Programmed Cell Death (PCD) suppression, cytoskeletal remodeling, and energy reallocation, suggesting red light activates receptors to induce pith proliferation. Overall, SL promotes reliable solid-stem phenotypes via light-mediated gene regulation, offering a sustainable strategy for WSS-resistant breeding and reduced lodging risks. Wheat farmers are losing millions of dollars every year because of the nutrient loss to the developing grain and lodging caused by the stem borer, WSS. Development of solid stem varieties with 100% pith expression not only reduces yield losses by saving grain quality and quantity but also benefits growers economically.