Hydrogen-rich water promotes the formation of bulblets in Lilium davidii var. unicolor through regulating sucrose and starch metabolism.

Abstract

This study examined how hydrogen-rich water (HRW) influences bulblet and adventitious root formation in scale cuttings of Lilium davidii var. unicolor. Among tested concentrations, 100% HRW produced the greatest increase in bulblet and adventitious root numbers compared with distilled water controls. RNA sequencing identified 1,702 differentially expressed genes (552 upregulated, 1,150 downregulated), with KEGG pathway analysis highlighting sucrose and starch metabolism as the most prominently enriched pathway. Carbohydrate metabolism genes showed notable differential expression (22 upregulated, 15 downregulated). qPCR validation confirmed expression changes in 12 key enzyme-coding genes, including glgc, Susy, otsA, glgP, BMY, and TPS. At the metabolite level, 100% HRW elevated sucrose and starch concentrations while reducing trehalose content in mother scales, consistent with the observed gene expression patterns. These findings indicate that HRW-driven accumulation of sucrose and starch may supply the energy substrate required for bulblet organogenesis.

Mechanism

HRW upregulates key carbohydrate metabolism genes (glgc, Susy, otsA, glgP, BMY, TPS), elevating sucrose and starch levels while reducing trehalose, thereby providing the energetic substrate that drives bulblet organogenesis in lily scale cuttings.