Trade-offs between silicon and phenolic defenses may explain enhanced performance of root herbivores on phenolic-rich plants

Frew, Adam ORCID: and Powell, Jeff R. and Sallam, Nader and Allsopp, Peter G. and Johnson, Scott N. (2016) Trade-offs between silicon and phenolic defenses may explain enhanced performance of root herbivores on phenolic-rich plants. Journal of Chemical Ecology, 42 (8). pp. 768-771. ISSN 0098-0331


Phenolic compounds play a role in plant defense against herbivores. For some herbivorous insects, particularly root herbivores, host plants with high phenolic concentrations promote insect performance and tissue consumption. This positive relationship between some insects and phenolics, however, could reflect a negative correlation with other plant defenses acting against insects. Silicon is an important element for plant growth and defense, particularly in grasses, as many grass species take up large amounts of silicon. Negative impact of a high silicon diet on insect herbivore performance has been reported aboveground, but is unreported for belowground herbivores. It has been hypothesized that some silicon accumulating plants exhibit a trade-off between carbon-based defense compounds, such as phenolics, and silicon-based defenses. Here, we investigated the impact of silicon concentrations and total phenolic concentrations in sugarcane roots on the performance of the root-feeding greyback canegrub (Dermolepida albohirtum). Canegrub performance was positively correlated with root phenolics, but negatively correlated with root silicon. We found a negative relationship in the roots between total phenolics and silicon concentrations. This suggests the positive impact of phenolic compounds on some insects may be the effect of lower concentrations of silicon compounds in plant tissue. This is the first demonstration of plant silicon negatively affecting a belowground herbivore.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 07 Nov 2019 03:45
Last Modified: 24 Feb 2020 23:03
Uncontrolled Keywords: carbon; insect herbivory; phenolics; silicon; sugarcane; trade-off
Fields of Research (2008): 06 Biological Sciences > 0602 Ecology > 060201 Behavioural Ecology
05 Environmental Sciences > 0503 Soil Sciences > 050303 Soil Biology
06 Biological Sciences > 0607 Plant Biology > 060799 Plant Biology not elsewhere classified
Fields of Research (2020): 31 BIOLOGICAL SCIENCES > 3103 Ecology > 310301 Behavioural ecology
41 ENVIRONMENTAL SCIENCES > 4106 Soil sciences > 410603 Soil biology
31 BIOLOGICAL SCIENCES > 3108 Plant biology > 310899 Plant biology not elsewhere classified
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9604 Control of Pests, Diseases and Exotic Species > 960414 Control of Plant Pests, Diseases and Exotic Species in Forest and Woodlands Environments
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