Acclimation of isoprene emission and photosynthesis to growth temperature in hybrid aspen: resolving structural and physiological controls

作者：Rasulov Bahtijor; Bichele Irina; Hueve Katja; Vislap Vivian; Niinemets Uelo^*

来源：Plant, Cell and Environment, 2015, 38(4): 751-766.

DOI：10.1111/pce.12435

• dimethylallyl diphosphate
• heat resistance
• isoprene synthase
• leaf anatomy
• optimum temperature
• photosynthetic electron transport rate
• photosynthesis rate
• temperature acclimation

Acclimation of foliage to growth temperature involves both structural and physiological modifications, but the relative importance of these two mechanisms of acclimation is poorly known, especially for isoprene emission responses. We grew hybrid aspen (Populus tremula x P.tremuloides) under control (day/night temperature of 25/20 degrees C) and high temperature conditions (35/27 degrees C) to gain insight into the structural and physiological acclimation controls. Growth at high temperature resulted in larger and thinner leaves with smaller and more densely packed chloroplasts and with lower leaf dry mass per area (M-A). High growth temperature also led to lower photosynthetic and respiration rates, isoprene emission rate and leaf pigment content and isoprene substrate dimethylallyl diphosphate pool size per unit area, but to greater stomatal conductance. However, all physiological characteristics were similar when expressed per unit dry mass, indicating that the area-based differences were primarily driven by M-A. Acclimation to high temperature further increased heat stability of photosynthesis and increased activation energies for isoprene emission and isoprene synthase rate constant. This study demonstrates that temperature acclimation of photosynthetic and isoprene emission characteristics per unit leaf area were primarily driven by structural modifications, and we argue that future studies investigating acclimation to growth temperature must consider structural modifications.

• 出版日期2015-4