Relationships among cold hardiness, water-soluble protein, anthocyanins, & free sugars in Hedera helix L.

Abstract

Water-soluble protein, measured by centrifu-gation of the ethanolic precipitate from homogenized leaves increased gradually from summer to winter with no sharp changes. But cold hardiness of whole leaves increased steeply when the weather became substantially colder in autumn and this increase was closely related to a sharp increase in total sugar as well as in anthocyanins. When the cold weather came late in the autumn of 1 year, so also did the anthocyanin increase and cold hardiness development. In spring, water-soluble protein continued at a high level into April in 2 separate years while leaves declined markedly in hardiness, anthocyanins, and substantially in sugars. Six and possibly 7 sugars, including glucose, fructose, sucrose, xylose, raffinose, stachyose, and arabinose were suspected of being present in winter, but only fructose, sucrose, and glucose in July.