Abstract:
The leaves of many trees emit volatile organic compounds (abbreviated as BVOCs), which protect them from various damages, such as herbivory, pathogens, and heat stress. For example, isoprene is highly volatile and is known to enhance the resistance to heat stress. In this study, we analyze the optimal seasonal schedule for producing isoprene in leaves to mitigate damage. We assume that photosynthetic rate, heat stress, and the stress-suppressing effect of isoprene may vary throughout the season. We seek the seasonal schedule of isoprene production that maximizes the total net photosynthesis using Pontryagin\'s maximum principle. The isoprene production rate is determined by the changing balance between the cost and benefit of enhanced leaf protection over time. If heat stress peaks in midsummer, isoprene production can reach its highest levels during the summer. However, if a large portion of leaves is lost due to heat stress in a short period, the optimal schedule involves peaking isoprene production after the peak of heat stress. Both high photosynthetic rate and high isoprene volatility in midsummer make the peak of isoprene production in spring. These results can be clearly understood by distinguishing immediate impacts and the impacts of future expectations.
摘要:
许多树木的叶子会释放出挥发性有机化合物(缩写为BVOCs),保护他们免受各种损害,如食草动物,病原体,和热应力。例如,异戊二烯是高度挥发性的并且已知增强对热应力的抗性。在这项研究中,我们分析了在叶片中生产异戊二烯以减轻损害的最佳季节时间表。我们假设光合速率,热应力,异戊二烯的压力抑制作用可能在整个季节有所不同。我们使用Pontryagin的最大原理寻求异戊二烯生产的季节性时间表,以最大程度地提高总的净光合作用。异戊二烯生产率由随时间的推移增强的叶片保护的成本和收益之间的平衡变化决定。如果热应激在盛夏达到高峰,异戊二烯产量可以在夏季达到最高水平。然而,如果在短时间内由于热应力而损失了大部分叶子,最佳时间表包括在热应力达到峰值后达到异戊二烯产量的峰值。盛夏时期较高的光合速率和较高的异戊二烯挥发性使得春季异戊二烯产量达到高峰。通过区分直接影响和未来预期的影响,可以清楚地理解这些结果。