Variability of stress metabolites content in the forms of <i>Pinus sylvestris</i> (Pinaceae) in dwarf shrub sphagnum pine forests (Arkhangelsk Region)

The variability of ascorbic acid and water-soluble proteins content in buds of Scots pine (Pinus sylvestris L.) forms growing under constant excessive moistening of northern taiga soils at the mouth of the Northern Dvina River was studied. The forms were distinguished by the types of seed scale apophyses and microstrobilus color. It was found that synthesis of ascorbic acid in buds of Scots pine with different types of seed scale apophyses depends on the seasonal factor. The content of water-soluble proteins in tree buds with convex (f. gibba Christ) and flat (f. plana Christ) apophysis types increases in autumn, which indicates the activation of protective response in preparation for overwintering. At the same time, in October 2022, the content of water-soluble proteins in pine buds with flat apophyses was significantly higher compared to the form with convex apophyses This indicates a stronger stress and activation of defense reactions in trees with flat apophyses. In pine trees with yellow (f. sulfuranthera Kozubov) and red (f. erythranthera Sanio) color of microstrobili, specific patterns in the synthesis of ascorbic acid were observed in certain years and months. In August 2022, the ascorbic acid content in buds of pine trees with yellow microstrobili was significantly higher than that of pine trees with red microstrobili. This indicates a stronger response of the form with yellow-coloured microstrobili to the stress factors. The dynamics of the water-soluble proteins content in pine buds with different microstrobilus color is determined by seasonal variability and is probably related to the development of bud structures and their preparation for the transition to winter dormancy.