Respiration as a percentage of daily photosynthesis in whole plants is homeostatic at moderate, but not high, growth temperatures
Respiration as a percentage of daily photosynthesis in whole plants is homeostatic at moderate, but not high, growth temperatures
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DOI：
10.1111/j.1469-8137.2007.02011.x
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发表时间：
2007-01-01
期刊：
影响因子：
9.4
通讯作者：
Pons, T. L.
中科院分区：
文献类型：
--
作者：
Atkin, O. K.;Scheurwater, I.;Pons, T. L.
在这里，我们研究了温度对来自不同生境的两种车前子物种碳经济的影响。低地大叶车前草和高山广叶车前子在三个恒定温度下进行水培：13、20和27摄氏度。使用完整植物在生长温度下测量芽中光合二氧化碳吸收率（P）和呼吸性二氧化碳释放率（R）以及根中的R。在每个生长温度下，改变气温以建立短期温度对 R 与 P 比率 (R/P) 的影响。在这两个物种中，在 13 和 20 摄氏度下生长的植物中，R/P 基本恒定。然而，在 27 摄氏度下生长的植物中，R/P 要大得多，特别是广叶杨。如果根部的生物量分配不随生长温度的升高而减少，则 27 摄氏度时 R/P 的增加会更大。气温的短期升高会增加两个物种的 R/P，其中气温的影响在 13 摄氏度下生长的植物中最为明显。我们得出的结论是，温度介导的生物量分配变化在确定整个植物的 R/P 值中发挥着重要作用，并且，虽然在中等生长温度下实现了 R/P 的稳态，但当植物暴露于高于自然栖息地通常经历的生长温度时，无法维持稳态。
Here, we investigated the impact of temperature on the carbon economy of two Plantago species from contrasting habitats.The lowland Plantago major and the alpine Plantago euryphylla were grown hydroponically at three constant temperatures: 13, 20 and 27 degrees C. Rates of photosynthetic CO2 uptake (P) and respiratory CO2 release (R) in shoots and R in roots were measured at the growth temperature using intact plants. At each growth temperature, air temperatures were changed to establish short-term temperature effects on the ratio of R to P (R/P).In both species, R/P was essentially constant in plants grown at 13 and 20 degrees C. However, R/P was substantially greater in 27 degrees C-grown plants, particularly in P. euryphylla. The increase in R/P at 27 degrees C would have been even greater had biomass allocation to roots not decreased with increasing growth temperature. Short-term increases in air temperature increased R/P in both species, with the effects of air temperature being most pronounced in 13 degrees C-grown plants.We conclude that temperature-mediated changes in biomass allocation play an important role in determining whole-plant R/P values, and, while homeostasis of R/P is achieved across moderate growth temperatures, homeostasis is not maintained when plants are exposed to growth temperatures higher than usually experienced in the natural habitat.