"Cos" it's worth it: Understanding and mitigating the impacts of ozone pollution on leafy salad crops

臭氧是一种高度活性的植物毒性分子，当它通过气孔被吸收时，会对植物细胞造成氧化损伤。先前已经证明，叶类植被对这种损害非常敏感，尽管已知不同物种的敏感性各不相同。臭氧破坏的早期症状之一是可见的损害，例如叶片颜色的变化（黄化）和叶片卷曲（脱落），这可能导致因叶子而收获的作物，如绿叶沙拉，迅速滞销。增加接触会导致功能下降和细胞死亡，从而降低生产力和产量。尽管如此，臭氧污染对敏感作物的影响在农业界并不为人所知或了解，可见的损害迹象往往被忽视或误诊。主要生长季节的臭氧浓度已经超过了破坏阈值，预计在气候变化的影响下还会进一步增加。此外，作物种类对臭氧和其他环境因素（如营养水平和灌溉以及作物保护）的敏感性不同，这些因素会影响影响的程度。因此，农学家迫切需要能够识别早期症状并采取行动，以减轻作物损失。本项目将结合室内实验、实地观察和试验以及建模，以达到以下目的：确定慢性和急性暴露于臭氧对一系列不同敏感性的沙拉品种的影响2。开发一种诊断工具，供农学家在田间使用，以识别臭氧破坏情况。确定控制两种不同沙拉品种的敏感性或耐受性的机制。量化在当前和未来臭氧污染水平下潜在的作物损失5。确定可行的作物管理措施以减少损失。

Ozone is a highly reactive phytotoxic molecule that causes oxidative damage to plant cells when it is taken up through the stomata. Leafy vegetation has been shown previously to be highly susceptible to such damage, although sensitivity is known to vary between different species. One of the early symptoms of ozone damage is visible injury, e.g. changes in leaf colour (chlorosis) and leaf curling (abscission), which can lead to crops harvested for their leaves such as leafy salads quickly becoming unsaleable. Increased exposure results in reduced functioning and cell death, reducing productivity and hence yield. In spite of this, the impacts of ozone pollution on sensitive crops are not well-known or understood in the agricultural community and the visible signs of damage are often overlooked or misdiagnosed.Ozone concentrations during the main growing season are already above the damage-threshold and are projected to increase further under climate change. Additionally, crop species differ in their sensitivity to ozone and other environmental factors such as nutrient levels and irrigation, along with crop protection, can influence the magnitude of the impacts. Therefore, there is a pressing need for agronomists to be able to recognise and act on the early symptoms to mitigate against crop loss.This project will combine chamber experiments, field observations and trials, and modelling to:1. determine the effects of chronic and acute exposure to ozone on a range of different salad species of differing sensitivity2. develop a diagnostic tool that agronomists can use in-field to recognise ozone damage3. identify the mechanisms governing the sensitivity or tolerance of two selected contrasting salad species4. quantify potential crop losses under current and future ozone pollution levels5. identify feasible crop management practices to mitigate losses.