DOI: 10.5061/dryad.r3s16
title: Data from: Increased root herbivory under elevated atmospheric carbon dioxide concentrations is reversed by silicon-based plant defences

description: 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. Sugarcane (Saccharum spp. hybrid) were subjected to fully
 factorial treatment combinations of ambient (aCO2) or elevated (eCO2)
 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 eCO2 and silicon
 supplementation affected performance and feeding behaviour (relative
 growth rate and relative consumption) in a 24-hour feeding efficiency
 assay. eCO2 and silicon supplementation increased rates of photosynthesis
 (+32% and 14%, respectively) sugarcane biomass (+45% and 69%,
 respectively). Silicon supplementation increased silicon concentrations in
 both leaves and roots by 54% and 75%, respectively. eCO2 caused root C:N
 to increase by 12%. Canegrub performance and consumption increased under
 eCO2; 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). 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 sugarcane susceptibility to herbivory and could be
 applicable in other crops.
description: Insect feeding trial
 dataFile containing data
 from the feeding trials. The column 'plant' is the identifier
 and can be used in conjunction with 'treatments' file for
 analysis.canegrub_feedingtrial.csvLeaf CNCarbon and nitrogen data from sugarcane leaves. The 'plant' column is the identifier to be used in conjunction with the 'treatments' file for analysis.leaf_CN.csvSugarcane photosynthesisPhotosynthesis data from each measuring 'event' throughout the experiment. The 'plant' column is the identifier to be used in conjunction with the 'treatments' file for analysis.photosynthesis.csvRoot CNCarbon and nitrogen data from sugarcane roots. The 'plant' column is the identifier to be used in conjunction with the 'treatments' file for analysis.root_CN.csvLeaf siliconData from silicon analysis of sugarcane leaves. The 'plant' column is the identifier to be used in conjunction with the 'treatments' file for analysis.silicon_leaves.csvRoot siliconData from silicon analysis of sugarcane roots. The 'plant' column is the identifier to be used in conjunction with the 'treatments' file for analysis.silicon_roots.csvtreatmentsIdentifier file to allow allocation of 'plant' to treatment combinations for analysis.Root total non structural carbsData from the total non-structural carbohydrate analysis of sugarcane roots. The 'plant' column is the identifier and should be used in combination with the 'treatments' file for analysis.TNC_roots.csvbiomassBiomass data from sugarcane plants. The column 'plant' is the identifier and can be used in conjunction with 'treatments' file for analysis.pot trialData from pot trial on insect performance including controls accounting for direct effects of treatments on insects.