Relationship between Dehydrins and Adaptation of Cajander Larch to Yakutia Cryolithozone Conditions

Abstract

Composition and seasonal fluctuations of stress dehydrin proteins of Cajander larch (Larix cajanderi Mayr) growing under extremely cold climatic conditions in Central Yakutia, which are notable for an extraordinary frost resistance, were investigated. Immunoblotting technique made it possible to detect major dehydrins in a molecular mass range of 17–20, 37–42, and 73 kD in the shoots of L. cajanderi for the first time. A high level of polymorphism of dehydrins within a population of L. cajanderi was detected and differences between the examined specimens of trees were mainly revealed in a molecular mass range of 20–37 kD. Within the circannual cycle of larch, the greatest seasonal fluctuations were observed in low-molecular dehydrins, with their content rising at the end of phenological autumn and reaching a steady level in the period of ultralow winter temperatures. The pattern of seasonal fluctuations and wide variety of dehydrins in larch shoots may point to their possible participation in the formation of a unique frost resistance of L. cajanderi upon adaptation of this conifer species to conditions existing in the cryolithozone.