CaCl 2 -HCl electrolyzed water promotes glucosinolates metabolism in broccoli sprouts via calcium signal

Abstract

AbstractBackground Electrolyzed water, an invention of green chemistry, is a novel disinfectant that has been widely used in the food field. Previous studies have found that slightly acidic electrolyzed water not only has a bactericidal effect, but also promotes the accumulation of active substances in many types of sprouts. We have developed a new type of electrolyzed water - CaCl2-HCl electrolyzed water (CHEW), which is an effective method to enhance the formation of glucosinolates and isothiocyanates of broccoli sprouts. Molecular mechanism of CaCl2-HCl electrolyzed water promoting glucosinolate metabolism in broccoli sprout during the growth was investigated in this study. Results On the 4th day, the total glucosinolates’ content of broccoli sprouts reached 195.50 µmol/g DW under CHEW treatment. On the 8th day, compared to tap water, the contents of 3 isothiocyanates (sulforaphane, erucin, 4-isothiocyanato-1-buene) in broccoli sprouts under CHEW treatment were significantly increased by 45.93%, 34.04% and 185.15% respectively. The results of calcium distribution and RT-qPCR indicated that CHEW treatment activated calcium signal in broccoli sprouts and promoted the relative expressions of glucosinolate biosynthesis-related genes through calcium sensors (calmodulin (CaM), calmodulin-like protein (CML), calcium-dependent protein kinase (CDPK)) and calcium-binding nuclear protein IQD1. Conclusion Our research provides new insights into the molecular mechanism of glucosinolate metabolism and also provided a theoretical basis for cultivating high-quality broccoli sprouts.