Root Herbivores Drive Changes to Plant Primary Chemistry, but Root Loss Is Mitigated under Elevated Atmospheric CO2.
Root Herbivores Drive Changes to Plant Primary Chemistry, but Root Loss Is Mitigated under Elevated Atmospheric CO2.
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DOI：
10.3389/fpls.2016.00837
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发表时间：
2016
影响因子：
5.6
通讯作者：
Vanbergen AJ
中科院分区：
文献类型：
--
作者：
McKenzie SW;Johnson SN;Jones TH;Ostle NJ;Hails RS;Vanbergen AJ
地上和地下食草动物是全球作物生产力和可持续农业的主要挑战。在人为气候变化下，这种来自多种草食性害虫的威胁将如何通过改变营养相互作用和植物反应性状而发生变化，这是了解未来作物对草食性害虫抗性的关键。在这项研究中，我们假设，大气中的碳富集将增加的数量（生物量）和质量（C：N比）的作物植物资源的地上和地下草食动物物种。在一个受控环境设施中，我们进行了一个小宇宙实验，使用大树莓蚜虫（Amphorophora idaei），根食幼虫的葡萄象甲（Occurrhynchus sulcatus），和树莓（Rubus idaeus）寄主植物。有四个草食动物处理（对照，蚜虫，象鼻虫和两种草食动物的组合）和环境（aCO 2）或升高（eCO 2）CO2处理（390对650 ± 50 μmol/mol）分配给两个树莓品种（cv Glen Ample或Glen Clova）不同的抗蚜虫草食动物。与我们的预测相反，eCO 2并没有增加作物生物量或植物组织的C：N比，也没有直接或通过寄主植物影响食草动物的丰度。根草食减少地下作物生物量下aCO 2，但不eCO 2，表明作物可以容忍攻击在CO2富集的环境。根草食动物也增加了在eCO 2的叶组织中的C：N比，可能是由于N的吸收减少，在根中发现的较低的N浓度。根草食动物大大增加了根C浓度下的CO2处理。我们的研究结果证实，作物生物量和生物化学对气候变化的反应需要在草食动物的背景下进行研究，因为生物相互作用与eCO 2对作物生产力的直接影响一样重要。
Above- and belowground herbivory represents a major challenge to crop productivity and sustainable agriculture worldwide. How this threat from multiple herbivore pests will change under anthropogenic climate change, via altered trophic interactions and plant response traits, is key to understanding future crop resistance to herbivory. In this study, we hypothesized that atmospheric carbon enrichment would increase the amount (biomass) and quality (C:N ratio) of crop plant resources for above- and belowground herbivore species. In a controlled environment facility, we conducted a microcosm experiment using the large raspberry aphid (Amphorophora idaei), the root feeding larvae of the vine weevil (Otiorhynchus sulcatus), and the raspberry (Rubus idaeus) host-plant. There were four herbivore treatments (control, aphid only, weevil only and a combination of both herbivores) and an ambient (aCO2) or elevated (eCO2) CO2 treatment (390 versus 650 ± 50 μmol/mol) assigned to two raspberry cultivars (cv Glen Ample or Glen Clova) varying in resistance to aphid herbivory. Contrary to our predictions, eCO2 did not increase crop biomass or the C:N ratio of the plant tissues, nor affect herbivore abundance either directly or via the host-plant. Root herbivory reduced belowground crop biomass under aCO2 but not eCO2, suggesting that crops could tolerate attack in a CO2 enriched environment. Root herbivory also increased the C:N ratio in leaf tissue at eCO2, potentially due to decreased N uptake indicated by lower N concentrations found in the roots. Root herbivory greatly increased root C concentrations under both CO2 treatments. Our findings confirm that responses of crop biomass and biochemistry to climate change need examining within the context of herbivory, as biotic interactions appear as important as direct effects of eCO2 on crop productivity.