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

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.

Changes in proteins within germinating seeds of transgenic wheat with an antisense construct directed against the thioredoxin.

Thioredoxin h is closely related to germination of cereal seeds. The mechanism of transgenic wheat seeds with antisense trxs gene, which is responsible for low germination rate was studied through analyzing the changes in proteins of wheat seeds during germination. The antisense trxs could weaken the metabolism of wheat seeds by decreasing the quantity of proteins involved in metabolism, while chloroform-methanol (CM) protein fraction consisted mostly of some low molecular weight proteins (<20 kD). Compared with wild-type wheat seeds, the folding of glutenin in transgenic wheat ones was affected during the wheat maturating. Big glutenin macropolymers could be formed more easily in transgenic wheat seeds than in wild-type wheat ones. Therefore, the degradation speed of glutenin in transgenic wheat seeds was slower than that in wild-type wheat ones during seed germination. In addition, the degradation of some proteins in transgenic wheat embryos was also delayed during germination.