Collins Nicholas C, Parent Boris
Australian Centre for Plant Functional Genomics, University of Adelaide, School of Agriculture Food and Wine, Hartley Grove, Urrbrae, South Australia 5064, Australia.
Australian Centre for Plant Functional Genomics, University of Adelaide, School of Agriculture Food and Wine, Hartley Grove, Urrbrae, South Australia 5064, Australia
AoB Plants. 2017 Jan 9;9(1). doi: 10.1093/aobpla/plw092.
There is a growing consensus in the literature that rising temperatures influence the rate of biomass accumulation by shortening the development of plant organs and the whole plant and by altering rates of respiration and photosynthesis. A model describing the net effects of these processes on biomass would be useful, but would need to reconcile reported differences in the effects of night and day temperature on plant productivity. In this study, the working hypothesis was that the temperature responses of CO assimilation and plant development rates were divergent, and that their net effects could explain observed differences in biomass accumulation. In wheat (Triticum aestivum) plants, we followed the temperature responses of photosynthesis, respiration and leaf elongation, and confirmed that their responses diverged. We measured the amount of carbon assimilated per "unit of plant development" in each scenario and compared it to the biomass that accumulated in growing leaves and grains. Our results suggested that, up to a temperature optimum, the rate of any developmental process increased with temperature more rapidly than that of CO assimilation and that this discrepancy, summarised by the CO assimilation rate per unit of plant development, could explain the observed reductions in biomass accumulation in plant organs under high temperatures. The model described the effects of night and day temperature equally well, and offers a simple framework for describing the effects of temperature on plant growth.
文献中越来越多的共识是，气温上升会通过缩短植物器官和整株植物的发育时间以及改变呼吸和光合作用速率来影响生物量积累速率。一个描述这些过程对生物量净影响的模型会很有用，但需要协调已报道的昼夜温度对植物生产力影响的差异。在本研究中，工作假设是CO同化和植物发育速率的温度响应是不同的，且它们的净效应可以解释观察到的生物量积累差异。在小麦（Triticum aestivum）植株中，我们追踪了光合作用、呼吸作用和叶片伸长的温度响应，并证实它们的响应是不同的。我们测量了每种情况下每“单位植物发育”同化的碳量，并将其与生长叶片和籽粒中积累的生物量进行比较。我们的结果表明，在达到最适温度之前，任何发育过程的速率随温度升高的速度比CO同化速率更快，并且这种差异（以每单位植物发育的CO同化速率概括）可以解释高温下植物器官中观察到的生物量积累减少。该模型对昼夜温度的影响描述得同样好，并为描述温度对植物生长的影响提供了一个简单的框架。
