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

增加大气CO2对植物防御病原体的影响当植物生长在高二氧化碳环境下时，植物叶片通常含有较低浓度的氮。因为植物对食草动物和病原体的防御是氮密集型的，大气中二氧化碳的增加可能会使植物更难对病原体进行有效的防御，特别是当它们需要同时防御食草动物的时候。我将把生长在当前和两倍于当前二氧化碳水平下的萝卜暴露在细菌病原体中，并测量水杨酸（病原体反应的信号分子）和抗病原体蛋白质的水平。我还将同时将一组植物暴露在模拟草食环境中，并测量蛋白酶抑制剂（一种富含氮的抗草食防御）的水平。总之，这些实验将使我能够确定在防御病原体和对抗食草动物之间是否存在权衡，以及随着大气中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.