Change of supercooling capability in solutions containing different kinds of ice nucleators by flavonol glycosides from deep supercooling xylem parenchyma cells in trees

► Low temperature adaptation of xylem parenchyma cells in trees by deep supercooling. ► Existence of supercooling-promoting four kinds of flavonol glycosides. ► Concentration-dependent both supercooling-promoting and ice nucleation-enhancing activities in quercetin 3-glucoside. ► Solution-dependent both supercooling and ice nucleation activities in flavonol glycosides. ► Presence of unknown ice nucleators in deep supercooling xylem parenchyma cells.