Increased root herbivory under elevated atmospheric carbon dioxide concentrations is reversed by silicon-based plant defences
Increased root herbivory under elevated atmospheric carbon dioxide concentrations is reversed by silicon-based plant defences
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DOI：
10.1111/1365-2664.12822
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发表时间：
2017-10-01
影响因子：
5.7
通讯作者：
Johnson, Scott N.
中科院分区：
文献类型：
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作者：
Frew, Adam;Allsopp, Peter G.;Johnson, Scott N.
1. 由于植物营养和防御的变化，预计大气中二氧化碳浓度的增加可能会改变许多植物对昆虫食草动物的敏感性。硅在植物抵御食草动物的防御中起着至关重要的作用，因此在植物中增加这种硅基防御可能有助于补救植物更容易受到食草动物侵害的情况。甘蔗（Saccharum spp. hybrid）受到环境（aCO(2)）或升高（eCO(2)）大气CO2浓度的全因子处理组合；环境硅或补硅；无虫的或由灰背线虫（Dermolepida albohirtum）以根为食的。一项温室研究被用来确定这些因素如何影响光合作用、生长、化学（硅、碳、氮和非结构性碳水化合物的浓度）的速率。在温室盆栽研究中确定了蛴螬质量的变化，并在24小时摄食效率测定中更详细地评估了eCO(2)和硅的补充如何影响生产性能和摄食行为（相对生长率和相对消耗）。增加CO2和硅的添加量可提高光合速率（分别为+32%和14%）和甘蔗生物量（分别为+45%和69%）。补硅使叶片和根系的硅含量分别提高了54%和75%。eCO(2)使根系C:N增加12%。eCO下蛴螬生产性能和消耗增加(2)；相对生长率（RGR）提高了116%，消耗的根料增加了57%（提示补食）。硅的施用逆转了这些影响，质量变化、RGR和根系消耗大幅下降（减少65%的根系消耗）。合成与应用。我们的研究结果表明，未来大气中的二氧化碳浓度可能会导致地下食草动物对作物的损害增加。土壤中生物有效硅的增加刺激了硅基防御，从而显著降低了食草动物和食草动物的性能。我们的研究结果表明，未来的害虫管理策略可能受益于农业土壤中生物可利用硅的缺乏特征和有针对性地施用硅肥。此外，未来的育种计划应利用品种间硅吸收的差异来提高作物新品种的硅吸收。硅基植物防御被证明对弥补大气变化对甘蔗草食敏感性的负面影响非常有益，并且可以应用于其他作物。
1. Predicted increases in atmospheric concentrations of CO2 may alter the susceptibility of many plants to insect herbivores due to changes in plant nutrition and defences. Silicon plays a critical role in plant defence against herbivores, so increasing such silicon-based defences in plants may help remediate situations where plants become more susceptible to herbivores.2. Sugar cane (Saccharum spp. hybrid) was subjected to fully factorial treatment combinations of ambient (aCO(2)) or elevated (eCO(2)) atmospheric CO2 concentrations; ambient silicon or silicon supplementation; insect-free or subject to root herbivory by greyback canegrub (Dermolepida albohirtum). A glasshouse study was used to determine how these factors affected rates of photosynthesis, growth, chemistry (concentrations of silicon, carbon, nitrogen and non-structural carbohydrates). Changes in canegrub mass were determined in the glasshouse pot study, together with more detailed assessment of how eCO(2) and silicon supplementation affected performance and feeding behaviour (relative growth rate and relative consumption) in a 24-h feeding efficiency assay.3. Elevated CO2 and silicon supplementation increased rates of photosynthesis (+32% and 14%, respectively) and sugar cane biomass (+45% and 69%, respectively). Silicon supplementation increased silicon concentrations in both leaves and roots by 54% and 75%, respectively. eCO(2) caused root C:N to increase by 12%.4. Canegrub performance and consumption increased under eCO(2); relative growth rate (RGR) increased by 116% and consumed 57% more root material (suggestive of compensatory feeding). Silicon application reversed these effects, with large decreases in mass change, RGR and root consumption (65% less root mass consumed).5. Synthesis and applications. Our results suggest future atmospheric carbon dioxide concentrations could lead to increased crop damage by a below-ground herbivore. Increasing bioavailable silicon in soil stimulated silicon-based defences which dramatically decreased herbivory and herbivore performance. Our findings suggest future pest management strategies could benefit from characterising deficiencies in bioavailable silicon in agricultural soils and targeted application of silicon fertilisers. Moreover, future breeding programmes should exploit variation in silicon uptake between cultivars to enhance silicon uptake in new crop varieties. Silicon-based plant defence proved to be highly beneficial for remediating the negative effects of atmospheric change on sugar cane susceptibility to herbivory and could be applicable in other crops.