Effect of Red Light on the Expression of the Phytochrome Gene Family and the Accumulation of Glycoside Alkaloids in Potatoes

Potatoes are the fourth major food crop in the world. Higher levels of glycoside alkaloids (GAs) lead to detrimental effects on the edibility and processing qualities. GAs are largely influenced by light; however, the mechanisms of this regulation by light are not well understood. By analyzing the bioinformatics of the phytochrome genes (PHYs) in potatoes, its expression level, the content of GAs and the correlation between them under different lights, this study aims to reveal the specific mechanism of light-regulated GAs accumulation and provide a theoretical basis for improved potato processing. Results based on high-performance liquid chromatography and imaging mass microscopy showed that red light induced a significant increase in alpha-chaconine and alpha-solanine accumulation compared to white light, but there was almost no accumulation in the dark within 12 days. Meanwhile, a bioinformatic analysis of PHY gene family members was performed, and the results showed that the five StPHYs were distributed on chromosomes 1, 2, 5, 7 and 10, with amino acid counts ranging from 704 to 1130. StPHYs genes have abundant light-responsive elements. Also, the expression patterns of StPHYs were dramatically induced by red light. Additionally, a correlation analysis showed that the GAs accumulation was significantly correlated with StPHYs expression. This research is useful for comprehending the metabolism of GAs regulated by light and monitoring food safety in potatoes.