Effect of Light Quality on the Expression of Glycoalkaloid Biosynthetic Genes Contributing to Steroidal Glycoalkaloid Accumulation in Potato

Light quality and intensity have severe impact on Steroidal glycoalkaloid (SGA) biosynthesis, causing the quality degradation of potato by greening and accelerating SGA-induced toxicity. In this study, Atlantic and Haryoung cultivars responded differently when exposed to seven light qualities viz., purple, red, blue, green, yellow, UV and fluorescent lights. Haryoung tuber exhibited a 44 % lesser SGA accumulation in yellow light compared to fluorescent light. Further screening of selected light sources by investigating the expression pattern of key genes and SGA contents, showed lower transcript levels of key genes in yellow light which in-turn reflected in the least amount of SGA accumulation with a 22 % lesser SGA levels in yellow light compared to fluorescent light. This suppression in the SGA accumulation suggests that yellow light can be used as an alternative light source instead of fluorescent light which would help in minimizing the quality degradation and SGA- induced toxicity.