Do biogenetic VOCs protect plant productivity under multiple environmental stress?

粮食安全在世界许多地区受到越来越大的威胁。气温上升和降水量的变化正在降低光合效率和作物产量。不断恶化的空气质量使农作物越来越多地暴露在破坏性的臭氧水平下，臭氧是一种强大的植物毒素，进一步降低了光合作用、生长和产量。这三种环境压力同时发生，它们之间的相互作用可以加剧或减轻各自的影响。这种复杂性是复杂的，因为许多植物也已经进化成合成挥发性有机化合物（VOC）作为对这种应激源的天然防御（Niinemets，J.S.等人，2010），但是一旦释放到大气中，这些VOC本身可以导致臭氧的形成（例如Fuentes等人，2000).学生使用最先进的设施来种植全球主要作物的选定品种（油菜，用于食品，饲料和生物燃料生产，已知会排放VOC，以前曾报道对臭氧敏感; Vandermeiren等人，2012）来研究多个共同发生的压力源（高温、干旱和暴露于臭氧）与保护性VOC的合成和释放之间的相互作用，以确定：1.不同品种间挥发性有机化合物排放量的差异; 2. VOC排放量在单独和组合环境压力下如何变化; 3.挥发性有机化合物的合成是否能够在解除胁迫后更快地恢复光合能力和/或限制对作物产量和作物品质的长期损害;我们将使用多变量回归分析来评估这些胁迫对作物产量、作物品质和挥发性有机化合物排放的影响，并确定bVOC排放的潜在保护作用。这些实验结果将用于开发剂量-反应关系，学生将其纳入全球排放模型（MEGAN，天然气体和气溶胶排放模型; Guenther等人，2012年），以了解预测的未来变化对作物生产和粮食安全的更广泛的影响和影响。

Food security is under increasing threat in many world regions. Rising temperatures and changes in precipitation are reducing photosynthetic efficiency and crop yields. Deteriorating air quality increasingly exposes crops to damaging levels of ozone, a powerful phytotoxin, which further reduces photosynthesis, growth and yield. These three environmental stresses occur in combination, and interactions between them can either exacerbate or ameliorate their individual impacts. This complexity is compounded as many plants have also evolved to synthesise volatile organic compounds (VOCs) as a natural defence against such stressors (Niinemets, Ü et al., 2010), but once released into the atmosphere these VOCs can themselves lead to the formation of ozone (e.g. Fuentes et al., 2000).The student use state-of-the-art facilities to grow selected cultivars of a major global crop (oilseed rape, used for food, fodder and biofuel production, known to emit VOCs and previously reported as sensitive to ozone; Vandermeiren et al., 2012) to investigate the interactions between multiple co-occurring stressors (high temperature, drought and exposure to ozone) and the synthesis and release of protective VOCs to determine: 1. how VOC emissions differ between cultivars; 2. how VOC emissions change under individual and combined environmental stresses; 3. whether VOC synthesis enables more rapid recovery of photosynthetic capacity after removal of stress and/or limits long-term impairment of crop yield and crop quality;We will use multi-variate regression analysis to assess the effect of these stresses on crop yield, crop quality and VOC emissions and determine the potential protective role of bVOC emissions. These experimental results will be used to develop dose-response relationships which the student will incorporate in a global emissions model (MEGAN, Model of Emissions of Gases and Aerosol from Nature; Guenther et al., 2012) to understand the wider scale impacts and implications of projected future change on crop production and food security.