Multiomic Analysis Reveals Core Regulatory Mechanisms underlying Steroidal Glycoalkaloid Metabolism in Potato Tubers

Abstract

Steroidal glycoalkaloids (SGAs) present in germinated potato tubers are toxic; however, the mechanisms underlying SGA metabolism are poorly understood. Therefore, integrated transcriptome, metabolome, and hormone analyses were performed in this study to identify and characterize the key regulatory genes, metabolites, and phytohormones related to glycoalkaloid regulation. Based on transcriptome sequencing of bud eyes of germinated and dormant potato tubers, a total of 6260 differentially expressed genes were identified, which were mainly responsible for phytohormone signal transduction, carbohydrate metabolism, and secondary metabolite biosynthesis. Two TCP14 genes were identified as the core transcription factors that potentially regulate SGA synthesis. Metabolite analysis indicated that 149 significantly different metabolites were detected, and they were enriched in metabolic and biosynthetic pathways of secondary metabolites. In these pathways, the α-solanine content was increased and the expression of genes related to glycoalkaloid biosynthesis was upregulated. Levels of gibberellin and jasmonic acid were increased, whereas that of abscisic acid was decreased. This study lays a foundation for investigating the biosynthesis and regulation of SGAs and provides the reference for the production and consumption of potato tubers.

SlZF3 regulates tomato plant height by directly repressing SlGA20ox4 in the gibberellic acid biosynthesis pathway

“…To measure the different compounds of gibberellin in SlZF3 -overexpressing lines, shoot apexes were collected from OE8 and OE37 seedlings (1 month old). The samples were sent to MetWare ( http://www.metware.cn/ ) for gibberellin measurement using an LC–MS/MS method according to a published protocol [ 76 ].…”

Metabolomics Reveals the Response Mechanisms of Potato Tubers to Light Exposure and Wounding during Storage and Cooking Processes

“…However, the quinones and steroids showed a small change not only in different cultivars, but also in each treatment (Table S3). An earlier investigation determined that a total of 505 metabolites were identified, with the majority consisting of lipids, amino acids and their derivatives, phenolic acids, alkaloids, and additional components [14]. The study indicated that the chlorogenic acid in potato peel exhibited promising antioxidant activity against soybean oil oxidation, and its antioxidant effect increased with the increase in the extract dose [20].…”

“…Interestingly, light exposure and wounding had a coupling effect on the variation in the SGA content during potato tuber storage [12], and this change showed a logistic regression pattern [13]. However, the SGA metabolism in potato tubers is different between germinated and dormant potato tubers [14]. These results may be due to the increased cellular metabolic activity in these areas, and researchers have indirectly verified the correlation between cell metabolic activity and SGA content from the perspective of cell substrates and related metabolic enzymes [13].…”

Potatoes dormancy release and sprouting commencement: A review on current and future prospects

“…Tubers that knock out GLYCOALKALOID BIOSYNTHESIS1 ( PGA1 ) and PGA2 (encoding the SGA biosynthetic gene) do not sprout during storage, which reveals the close relationship between SGA biosynthesis and dormancy: with the end of dormancy comes the accumulation of SGA (Umemoto et al., 2016). The transcription factor TCP14, which contributes to inhibiting dormancy by participating in gibberellin (GA) biosynthesis and signal transduction, has recently been proven to regulate solanine accumulation (Shen et al., 2022). Sterol side chain reductase 2 (SSR2), a key enzyme in the biosynthesis of SGAs, is expected to be a potential target for potato breeding with low SGAs accumulation (Sawai et al., 2014).…”