PDF(Pubmed)
Abstract：
Tropospheric ozone (O3) pollution can affect plant nutritional quality and secondary metabolites by altering plant biochemistry and physiology, which may lead to unpredictable effects on crop quality and resistance to pests and diseases. Here, we investigated the effects of O3 (ambient air, Am; ambient air +80 ppb of O3, EO3) on the quality compounds and chemical defenses of a widely cultivated tea variety in China (Camellia sinensis cv. \'Baiye 1 Hao\') using open-top chamber (OTC). We found that elevated O3 increased the ratio of total polyphenols to free amino acids while decreasing the value of the catechin quality index, indicating a reduction in leaf quality for green tea. Specifically, elevated O3 reduced concentrations of amino acids and caffeine but shows no impact on the concentrations of total polyphenols in tea leaves. Within individual catechins, elevated O3 increased the concentrations of ester catechins but not non-ester catechins, resulting in a slight increase in total catechins. Moreover, elevated O3 increased the emission of biogenic volatile organic compounds involved in plant defense against herbivores and parasites, including green leaf volatiles, aromatics, and terpenes. Additionally, concentrations of main chemical defenses, represented as condensed tannins and lignin, in tea leaves also increased in response to elevated O3. In conclusion, our results suggest that elevated ground-level O3 may reduce the quality of tea leaves but could potentially enhance the resistance of tea plants to biotic stresses.
摘要：
对流层臭氧（O3）污染可通过改变植物的生化和生理，影响植物的营养品质和次生代谢产物。这可能会对作物品质和对病虫害的抗性产生不可预测的影响。这里,我们调查了O3(环境空气，Am;环境空气+80ppb的O3，EO3）对中国广泛种植的茶叶品种的质量化合物和化学防御能力（山茶cv。\'百业1号号\')使用开放式腔室(OTC)。我们发现，升高的O3增加了总多酚与游离氨基酸的比例，同时降低了儿茶素质量指标的值，表明绿茶的叶子质量降低。具体来说,升高的O3降低了氨基酸和咖啡因的浓度，但对茶叶中总多酚的浓度没有影响。在个别儿茶素中，升高的O3增加了酯儿茶素的浓度，而不是非酯儿茶素的浓度，导致总儿茶素略有增加。此外，升高的O3增加了植物防御草食动物和寄生虫的生物挥发性有机化合物的排放，包括绿叶挥发物，芳烃，和萜烯。此外,主要化学防御的浓度，表示为缩合单宁和木质素，茶叶中的O3含量也增加了。总之,我们的结果表明，升高的地面O3可能会降低茶叶的质量，但可能会增强茶树对生物胁迫的抵抗力。
