Short-term severe drought influences root volatile biosynthesis in eastern white pine (Pinus strobus L)

Area of Science:

• Plant physiology and biochemistry
• Climate change adaptation
• Forest ecology

Background:

• Climate change is increasing drought frequency and severity globally.
• Drought stress is predicted to alter carbon partitioning in trees, potentially affecting volatile organic compound (VOC) biosynthesis.
• The specific impacts of drought on VOCs in species like eastern white pine (Pinus strobus) are not well understood.

Purpose of the Study:

• To investigate the physiological and biochemical responses of eastern white pine to severe drought stress.
• To analyze the impact of drought on volatile organic compound (VOC) synthesis in the roots of eastern white pine.
• To elucidate the mechanisms of drought tolerance in Pinus strobus related to VOC production.

Main Methods:

• Eastern white pine plants were subjected to 32 days of severe drought.
• Physiological measurements included chlorophyll content, leaf water content, and root/shoot ratio.
• Biochemical analyses encompassed non-structural carbohydrates, proline, lipid peroxidation, antioxidant activity, and root abscisic acid content.
• Total root VOCs were analyzed, focusing on monoterpene and sesquiterpene synthesis.

Main Results:

• Drought significantly reduced water content, leaf chlorophyll, and fresh weight, while increasing root proline and antioxidant activity.
• Abscisic acid content in roots increased significantly under drought conditions.
• Monoterpene synthesis increased by 16%, whereas sesquiterpene synthesis decreased by 3% in drought-stressed plants.

Conclusions:

• Eastern white pine exhibits significant physiological and biochemical adjustments to severe drought stress.
• Drought stress alters VOC profiles, favoring monoterpenes over sesquiterpenes, potentially contributing to drought tolerance.
• These findings provide insights into the molecular mechanisms of drought adaptation in Pinus strobus.