Effect of water stress on the accumulation of dehydrins in callus culture cells from Pinus sylvestris L.

Abstract

Intraspecific differences in the level of stress tolerance in woody plants remain understudied, even though this characteristic is important for tree breeding. Dehydrins are intracellular defense proteins that protect other proteins, as well as membranes, from damage caused by intracellular dehydration under water stress. The present paper aims to examine the possibility of detecting dehydrins produced in response to water stress, as well as interindividual differences in dehydrin accumulation in Pinus sylvestris L. (Scots pine) under in vitro conditions. In this work, callus culture derived from the branch and bud tissues of two Scots pine trees (T3 and T4) was used; for these trees, quantitative and qualitative differences in the composition of dehydrins were found. Interindividual differences in callus cultures were expressed as variations in the frequency of callus formation events and callus culture growth index. With the addition of 5 or 8% polyethylene glycol to the culture medium, the effect of water stress on the callus culture was expressed in a dose-dependent decrease of water content in callus cells, as well as the accumulation of shock protein Hsp70 and dehydrins having masses of 47, 42, and 27 kDa. The composition of dehydrins and the level of their accumulation differed between calluses derived from T3 and T4, suggesting different levels of water stress tolerance in the cells of these callus cultures. The existence of such differences may provide a basis for detecting dehydrins in Scots pine produced in response to water stress.