Effects of Zn Stress on Physiological Characteristics of Hylotelephium spectabile Studies on the Adaptation of Taxus media cv. Hicksii to Natural Temperature Reduction Changes in contents of MDA and osmoregulatory substances during snow cover for Pyrola dahurica Effects of graft with pumpkin rootstock on nitrogen metabolism and protein expression in the cucumber seedlings under iso-osmotic Ca(NO3)2 or NaCl stress