Metabolome and Transcriptome Analyses Reveal the Correlation Between Fructan Changes and Phytohormone Regulation During Tuber Sprouting of Helianthus tuberosus L.

Jerusalem artichoke (Helianthus tuberosus L.) reproduces asexually through tubers, which are rich in fructan-type carbohydrates and serve as the primary processing organ. Plant hormones may regulate the sprouting process of tubers, but the changes in fructans and their regulatory mechanisms in relation to hormones remain unclear. This study utilized two varieties of Jerusalem artichoke, “Qingyu No.1” and “Qingyu No.3”, to analyze the changes in the proportion of carbohydrates (especially fructans) in total sugars during the sprouting process. Metabolomic and transcriptomic analyses were conducted at three selected sprouting stages. The results indicated that during tuber sprouting, carbohydrates such as fructans play a regulatory role through conversion activities. Multi-omics analysis revealed that jasmonic acid and salicylic acid promote Jerusalem artichoke sprouting through metabolism and are involved in the plant hormone signal transduction process. Differentially expressed genes related to hormone signaling were screened and divided into three groups based on expression levels. It was found that the proportion of carbohydrates is highly correlated with the expression of hormone-related genes in the sprouts, suggesting that plant hormones may regulate carbohydrate metabolism during the sprouting of Jerusalem artichoke tubers. In conclusion, these results preliminarily elucidate the regulatory mechanisms of plant hormones in Jerusalem artichoke tuber sprouting, aiming to provide a theoretical basis for the production and processing of Jerusalem artichoke.