The Impact of Increased Atmospheric Carbon Dioxide on the Nitrogen Status and Alkaloid Content in Lupinus: Implications for Plant/Herbivore Interactions

增加的二氧化碳将对植物产生重大影响- 包括增加光合作用，增加生长，减少 水分利用和组织氮减少。 这些更改将 在具有共生固氮作用的豆科植物中， 细菌 固氮速率通常由以下因素决定： 可用的光吸收剂或结节的大小。 的影响 两种羽扇豆（Lupinus）上增加的二氧化碳将 在杜克人工气候室进行调查 这些植物含有氮 固定结核，因此可能会增加 随着CO2浓度的增加而固定。 此外，羽扇豆 有生物碱作为它们的抗草食动物防御化合物。 以来 生物碱含有氮，增加的二氧化碳很可能 也影响生物碱浓度。 研究这个 相互作用，羽扇豆将在三个不同的 CO2浓度和三种不同水平的树叶 损害 这些植物的叶子将被分析 在化学成分，并将饲料的本地物种， 食草动物，Orgyia vetusta。 这项研究是第一个 研究植物、其 固氮共生体和草食动物。 结果将是 对研究大气气体和全球气候变化的人来说， 改变问题。

Increased co2 will have major impacts on plants--- including increased photosynthesis, increased growth, decreased water use, and decreased tissue nitrogen. These changes will be even more intense in legumes which have symbiotic nitrogen-fixing bacteria. Rates of nitrogen fixation are often determined by available photosynthate or size of nodules. The impact of increased co2 on two species of lupines (Lupinus) will be investigated at the Duke Phytotron. These plants have nitrogen- fixing nodules and thus are likely to have increased rates of fixation as co2 concentrations increase. In addition, lupines have alkaloids as their anti-herbivore defense compounds. Since alkaloids contain nitrogen, increased co2 is very likely to impact on alkaloid concentration as well. To study this interaction, lupines will be grown under three different concentrations of co2 and three different levels of foliage damage. Foliage from these plants will be analyzed for changes in chemical composition, and will be fed to a native species of herbivore, Orgyia vetusta. This research is the first to investigate a three-level interaction between a plant, its nitrogen-fixing symbiont, and herbivore. Results will be of great interest to those studying atmosheric gases and global change issues.