Dissertation Research: The Effects of Elevated CO2 on Plants, Pathogens, Herbivores, and Natural Enemies: Ecological Consequences and Evolutionary Potentials

DDIG-DEB-010509增加大气CO2对植物防御病原体的影响当生长在高浓度的二氧化碳下时，植物叶片通常含有较低浓度的氮。 由于植物对食草动物和病原体的防御是氮密集型的，大气中二氧化碳浓度的上升可能会使植物更难对病原体进行有效的防御，特别是如果它们同时需要防御食草动物的话。我将在目前和两倍于目前的二氧化碳水平下种植的芜菁暴露于细菌病原体，并测量水杨酸（病原体反应中的信号分子）和抗病原体蛋白质的水平。 我还将同时将一部分植物暴露于模拟食草动物，并测量蛋白酶抑制剂（一种富氮的抗食草动物防御）的水平。 总之，这些实验将使我能够确定在防御病原体和防御食草动物之间是否存在权衡，以及随着大气二氧化碳的持续上升，这种权衡是否会变得更加严重。

DDIG - DEB-010509The Effects of Increasing Atmospheric CO2 on Plant Defense Against Pathogens When grown under elevated carbon dioxide, plant leaves typically contain lower concentrations of nitrogen. Because plant defenses against herbivores and pathogens are nitrogen-intensive, rising atmospheric CO2 may make it more difficult for plants to mount an effective defense against pathogens, particularly if they are required to defend themselves against an herbivore at the same time.I will expose turnip grown under current and twice current levels of CO2 to a bacterial pathogen, and measure levels of both salicylic acid (a signal molecule in pathogen response) and anti-pathogen proteins. I will also simultaneously expose a subset of plants to simulated herbivory, and measure levels of protease inhibitors (a nitrogen-rich anti-herbivore defense). Together, these experiments will allow me to determine whether there is a trade-off between defense against pathogens and against herbivores, and whether this trade-off will become more severe as atmospheric CO2 continues to rise.