Cook Daniel, Gardner Dale R, Pfister James A, Stonecipher Clinton A, Robins Joseph G, Morgan Jack A
USDA/ARS Poisonous Plant Research Laboratory, Logan, UT, 84341, USA.
USDA/ARS Forage and Range Research Laboratory, Logan, UT, 84341, USA.
J Chem Ecol. 2017 Mar;43(3):307-316. doi: 10.1007/s10886-017-0820-5. Epub 2017 Feb 11.
Rapid changes in the Earth's atmosphere and climate associated with human activity can have significant impacts on agriculture including livestock production. CO concentration has risen from the industrial revolution to the current time, and is expected to continue to rise. Climatic changes alter physiological processes, growth, and development in numerous plant species, potentially changing concentrations of plant secondary compounds. These physiological changes may influence plant population density, growth, fitness, and toxin concentrations and thus influence the risk of toxic plants to grazing livestock. Locoweeds, swainsonine-containing Astragalus species, are one group of plants that may be influenced by climate change. We evaluated how two different swainsonine-containing Astragalus species responded to elevated CO concentrations. Measurements of biomass, crude protein, water soluble carbohydrates and swainsonine concentrations were measured in two chemotypes (positive and negative for swainsonine) of each species after growth at CO levels near present day and at projected future concentrations. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO in the two species. Swainsonine concentrations were not strongly affected by elevated CO in the two species. In the different chemotypes, biomass responded negatively and crude protein concentrations responded positively in the swainsonine-positive plants compared to the swainsonine-negative plants. Ultimately, changes in CO and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, but it is difficult to predict how these changes will impact plant herbivore interactions.
与人类活动相关的地球大气和气候的快速变化会对包括畜牧业生产在内的农业产生重大影响。从工业革命到现在，二氧化碳浓度一直在上升，预计还将继续上升。气候变化会改变许多植物物种的生理过程、生长和发育，可能会改变植物次生化合物的浓度。这些生理变化可能会影响植物种群密度、生长、适合度和毒素浓度，从而影响有毒植物对放牧牲畜的风险。疯草，即含有苦马豆素的黄芪属植物，是一类可能受到气候变化影响的植物。我们评估了两种不同的含有苦马豆素的黄芪属植物对升高的二氧化碳浓度的反应。在接近当前水平和预计未来浓度的二氧化碳水平下生长后，对每个物种的两种化学类型（苦马豆素阳性和阴性）的生物量、粗蛋白、水溶性碳水化合物和苦马豆素浓度进行了测量。在这两个物种中，生物量和水溶性碳水化合物浓度对升高的二氧化碳呈正反应，而粗蛋白浓度呈负反应。苦马豆素浓度在这两个物种中受升高的二氧化碳影响不大。在不同的化学类型中，与苦马豆素阴性植物相比，苦马豆素阳性植物的生物量呈负反应，粗蛋白浓度呈正反应。最终，二氧化碳和内生菌状态的变化可能会改变疯草等有毒植物的多种生理反应，但很难预测这些变化将如何影响植物与食草动物之间的相互作用。
