Compositae Plants Differed in Leaf Cuticular Waxes between High and Low Altitudes.

Area of Science:

• Plant Ecology
• Biogeochemistry
• Chemical Ecology

Background:

• Leaf cuticular wax plays a crucial role in plant adaptation to environmental conditions.
• Altitude-related environmental factors, such as temperature and UV radiation, can influence plant physiology and biochemistry.
• Compositae family exhibits diverse adaptations across various habitats.

Purpose of the Study:

• To investigate the differences in leaf cuticular wax composition of Compositae species between high and low altitudes.
• To analyze the impact of altitude on wax chemical composition, including n-alkanes, fatty acids, and alcohols.
• To determine how these variations contribute to plant adaptation strategies.

Main Methods:

• Sampling of eight Compositae species at high altitude (3482 m) and seven at low altitude (220 m).
• Analysis of leaf cuticular wax chemical composition and content.
• Calculation of wax parameters: average chain length (ACL), carbon preference index (CPI), dispersion (d), d/N, and Norm31.

Main Results:

• Total wax amounts and compositions were generally higher at high altitude, with exceptions for primary alcohol, secondary alcohol, and ketone.
• n-alkane distribution varied, with C29 dominating at high altitudes and C31/C33 at low altitudes.
• Higher ACL, CPI, d, d/N, and Norm31 values were observed at low altitude, indicating different wax structures and functions.

Conclusions:

• Leaf cuticular wax composition in Compositae is significantly influenced by altitude.
• Variations in wax components, such as n-alkanes and chain lengths, are adaptive strategies for environmental stress tolerance.
• These adaptations facilitate the expansion of Compositae distribution across diverse altitudes.