Spectral light regulation enhances sprouting, physiological efficiency, and ionomic homeostasis in Western Himalayan buckwheat

Abstract

This study examined the effects of different spectral LED (light-emitting diode) light treatments on growth performance, physiological responses, and underlying ionomic variations in 6-day-old sprouts of two underutilized western Himalayan buckwheat species, namely Fagopyrum esculentum Moench (common buckwheat) and F. tataricum Gaertn. (Tartary buckwheat). Both species responded differentially to spectral modulation, exhibiting variation in overall growth and elemental distribution. The highest biomass accumulation was predominantly reported in common buckwheat, whereas Tartary buckwheat showed a more pronounced ionomic shift across different spectral treatments. Blue light significantly enhanced elemental concentrations in both species. Specifically, it improved Na, Mn, Mg, Co, and Cu concentrations in Tartary buckwheat, whereas B, Fe, and Cu concentrations in common buckwheat. Multivariate analysis, including hierarchical clustering and principal component analysis, confirmed distinct ionomic separation patterns between treated and control groups. A linear association was also revealed among several elemental pairs, indicating coordinated nutrient regulation in response to spectral light modulation. Blue light further improved APX, CAT, Vitamin C, and total protein levels in both species, whereas red light stimulated SOD activity, demonstrating wavelength-specific regulation of enzymatic antioxidative potential. In contrast, the 70Blue: 30Red spectral combination increased the total sugar content while simultaneously promoting the accumulation of photosynthetic and photoprotective pigments. The study explicitly highlights the importance of species-specific lighting strategies tailored to the targeted enhancement of biomass, pigments, antioxidants, and ionomic profile in a controlled environment. Additionally, the findings offer a promising approach for advancing the functional and nutraceutical quality of Himalayan buckwheat sprouts, ultimately improving their consumer acceptance and commercial potential.