Adaptation of Pinyon Pine Seedlings to Combined Water and Heat Stress: using biochemical markers

The objective of this study is to analyze the effects of water and heat stress on pine nut seedlings grown under semi-controlled conditions. Changes in proline content, soluble sugars, and chlorophyll pigments are monitored in various plant organs (needles, stems, and roots). Three levels of water stress were identified based on soil water saturation at 75%, 55%, and 35%; thermal stress was applied at increasing temperatures of 38°C, 44°C, and 50°C for a duration of 3 hours to quantify the levels of biochemical markers in one-year-old seedlings. The results show a significant increase in proline levels in the needles at 38°C and high levels of soluble sugars in the needles at 25°C (control), 38°C, 44°C, and 50°C, while a decrease was observed in their chlorophyll pigments.