Ow Lai Fern, Whitehead David, Walcroft Adrian S, Turnbull Matthew H
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
Funct Plant Biol. 2008 Aug;35(6):448-461. doi: 10.1071/FP08104.
Pinus radiata L. were grown in climate-controlled cabinets under three night/day temperature treatments, and transferred between treatments to mimic changes in growth temperature. The objective was to determine the extent to which dark respiration and photosynthesis in pre-existing and new needles acclimate to changes in growth temperatures. We also assessed whether needle nitrogen influenced the potential for photosynthetic and respiratory acclimation, and further assessed if short-term (instantaneous, measured over a few hours) respiratory responses are accurate predictors of long-term (acclimated, achieved in days-weeks) responses of respiration to changing temperature. Results show that respiration displayed considerable potential for acclimation. Cold and warm transfers resulted in some acclimation of respiration in pre-existing needles, but full acclimation was displayed only in new needles formed at the new growth temperature. Short-term respiratory responses were poor predictors of the long-term response of respiration due to acclimation. There was no evidence that photosynthesis in pre-existing or new needles acclimated to changes in growth temperature. N status of leaves had little impact on the extent of acclimation. Collectively, our results indicate that there is little likelihood that respiration would be significantly stimulated in this species as night temperatures increase over the range of 10-20°C, but that inclusion of temperature acclimation of respiration would in fact lead to a shift in the balance between photosynthesis and respiration in favour of carbon uptake.
辐射松在气候控制箱中进行三种昼夜温度处理培养，并在不同处理之间转移以模拟生长温度的变化。目的是确定原有针叶和新针叶的暗呼吸和光合作用对生长温度变化的适应程度。我们还评估了针叶氮含量是否影响光合和呼吸适应的潜力，并进一步评估短期（即时，在数小时内测量）呼吸反应是否是呼吸对温度变化的长期（适应，在数天至数周内实现）反应的准确预测指标。结果表明，呼吸显示出相当大的适应潜力。冷转移和热转移导致原有针叶的呼吸有一定程度的适应，但只有在新生长温度下形成的新针叶中才表现出完全适应。由于适应，短期呼吸反应对呼吸的长期反应预测效果不佳。没有证据表明原有针叶或新针叶的光合作用适应了生长温度的变化。叶片的氮素状况对适应程度影响很小。总体而言，我们的数据表明，随着夜间温度在10-20°C范围内升高，该物种的呼吸作用不太可能受到显著刺激，但呼吸作用的温度适应实际上会导致光合作用与呼吸作用之间的平衡向有利于碳吸收的方向转变。
