Thiol content of spruce needles at forest limits

Area of Science:

• Plant Physiology
• Environmental Stress Response
• Forest Ecology

Background:

• Coniferous trees like spruce (Picea) are exposed to varying environmental conditions.
• Water-soluble thiol (SH) content and osmolality are key indicators of plant stress and adaptation.
• Understanding how altitude and season affect these physiological markers is crucial for forest health.

Purpose of the Study:

• To investigate the influence of altitude and provenance on water-soluble thiol (SH) content and cell sap osmolality in spruce trees.
• To determine the seasonal variations in SH content, protein-bound SH, and glutathione reductase activity.
• To assess the adaptive responses of spruce trees to different altitudinal environments.

Main Methods:

• Spruce trees from low- and high-altitude origins were transplanted to test sites at 400 m and 1700 m.
• Water-soluble thiol (SH) content and osmolality of cell sap were measured.
• Annual patterns of water-soluble and protein-bound SH content and glutathione reductase activity were monitored at 1700 m.

Main Results:

• No significant difference in SH content or osmotic value was observed between trees of different origins at the same altitude.
• Sulfhydryl (SH) content was significantly higher at the higher cultivation altitude (1700 m) compared to the lower altitude (400 m).
• Both SH content and osmotic value were elevated during winter, irrespective of altitude and tree origin, and peaked in winter, being lowest in summer.

Conclusions:

• Cultivation altitude and season are critical factors influencing SH content and osmolality in spruce trees.
• Spruce trees exhibit physiological adjustments to higher altitudes and seasonal changes, indicated by increased SH content and osmotic values.
• These findings highlight the adaptive capacity of spruce to environmental stressors, particularly cold and high-altitude conditions.