Transcriptomics integrated with metabolomics reveals the mechanism of CaCl₂-HCl electrolyzed water-induced glucosinolate biosynthesis in broccoli sprouts

Glucosinolates are important phytochemicals in Brassicaceae. We investigated the effect of CaCl₂-HCl electrolyzed water (CHEW) on glucosinolates biosynthesis in broccoli sprouts. The results showed that CHEW treatment significantly decreased reactive oxygen species (ROS) and malondialdeh yde (MDA) contents in broccoli sprouts. On the the 8^th day, compared to tap water treatment, the the total glucosinolate content of broccoli sprouts with CHEW treatment increased by 10.6% and calcium content was dramatically enhanced from 14.4 mg/g DW to 22.7 mg/g DW. Comparative transcriptome and metabolome analyses revealed that CHEW treatment activated ROS and calcium signaling transduction pathways in broccoli sprouts and they interacted through MAPK cascades. Besides, CHEW treatment not only promoted the biosynthesis of amino acids, but also enhanced the expression of structural genes in glucosinolate synthesis through transcription factors (MYBs, bHLHs, WRKYs, etc.). The results of this study provided new insights into the regulatory network of glucosinolates biosynthesis in broccoli sprouts under CHEW treatment.