The protection of wheat plasma membrane under cold stress by glycine betaine overproduction

We aimed to study the protection of wheat plasma membrane (PM) under cold stress (0–2 °C) by the overaccumulation of glycine betaine (GB). For this, we used wild-type winter wheat (Triticum aestivum L.) cv. Shi 4185 (WT) and 3 transgenic lines (T1, T4, and T6) expressing the BADH gene isolated from Atriplex hortensis L. Under cold stress, the transgenic lines with higher GB content maintained better membrane integrity and higher plasma membrane H⁺-ATPase activity than WT. In these transgenic lines, ROS production and membrane lipid peroxidation were lower, while antioxidative enzyme activities and compatible solute contents were higher in comparison with WT. This may be attributable to their enhanced cold-stress tolerance mediated by GB overproduction.