Date

Fall 12-11-2025

Advisor

Aniruddha Acharya

Program Director

Jamie Stacy

Document Type

Paper

Abstract

Potassium is an essential macronutrient for plant growth and development, yet excessive potassium fertilization can induce salt stress with detrimental consequences for crop productivity and nutritional quality. Despite its agricultural relevance, potassium chloride induced stress remains significantly understudied compared to classical sodium-based salinity. This thesis investigates the physiological, biochemical, and molecular responses of Raphanus sativus to KCl stress using an integrated approach that combines germination assays, mineral profiling, and gene expression analysis.

Radish seeds were exposed to increasing KCl concentrations (0–400 mM) with or without melatonin, TEA, or EDTA. Germination percentage, fresh and dry biomass, and early seedling vigor were recorded. Mineral accumulation across developmental stages was quantified using ICP-OES, while aquaporin and superoxide dismutase gene expression levels were analyzed using RT-qPCR.

Results demonstrate that KCl significantly inhibits germination in a concentration dependent manner, with severe reductions between 300 to 400 mM range. TEA consistently improved germination across all treatments, suggesting a protective role in regulating K+ flux, whereas melatonin and EDTA produced variable or inhibitory effects. ICP-OES analysis revealed substantial disruptions in nutrient homeostasis, including elevated iron and aluminum accumulation under high stress and reduced levels of calcium and magnesium. Gene expression profiling revealed downregulation of both aquaporin and SOD genes, implicating impaired water transport and a compromised antioxidant defense system.

Together, these findings highlight potassium toxicity as a multifaceted stressor that impacts radish development across physiological and molecular scales. This work provides a foundation for future studies aimed at improving crop resilience, optimizing fertilizer management, and advancing our understanding of potassium-induced stress in agriculturally important species.

Recommended Citation

Oelke, Mason P., "Investigating the Effect of KCl Stress in Raphanus sativus" (2025). ATU Honors Projects. https://orc.library.atu.edu/atu_honors/

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