| Title: | "When resistance is futile, tolerate instead: silicon promotes plant compensatory growth when attacked by above- and belowground herbivores" |
| Author(s): | Johnson SN; Reynolds OL; Gurr GM; Esveld JL; Moore BD; Tory GJ; Gherlenda AN; |
| Address: | "Hawkesbury Institute for the Environment, Western Sydney University, Sydney, New South Wales, Australia. Graham Centre for Agricultural Innovation, Wagga Wagga, New South Wales, Australia. Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China. New South Wales Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, New South Wales, Australia. Graham Centre for Agricultural Innovation, Charles Sturt University, Orange, New South Wales, Australia. Australian Steel Mill Services, Port Kembla, New South Wales, Australia" |
| ISSN/ISBN: | 1744-957X (Electronic) 1744-9561 (Print) 1744-9561 (Linking) |
| Abstract: | "Plants have evolved numerous herbivore defences that are resistance- or tolerance-based. Resistance involves physical and chemical traits that deter and/or harm herbivores whereas tolerance minimizes fitness costs of herbivory, often via compensatory growth. The Poaceae frequently accumulate large amounts of silicon (Si), which can be used for herbivore resistance, including biomechanical and (indirectly) biochemical defences. To date, it is unclear whether Si improves tolerance of herbivory. Here we report how Si enabled a cereal (Triticum aestivum) to tolerate damage inflicted by above- and belowground herbivores. Leaf herbivory increased Si concentrations in the leaves by greater than 50% relative to herbivore-free plants, indicating it was an inducible defensive response. In plants without Si supplementation, leaf herbivory reduced shoot biomass by 52% and root herbivory reduced root biomass by 68%. Si supplementation, however, facilitated compensatory growth such that shoot losses were more than compensated for (+14% greater than herbivore-free plants) and root losses were minimized to -16%. Si supplementation did not improve plant resistance since Si did not enhance biomechanical resistance (i.e. force of fracture) or reduce leaf consumption and herbivore relative growth rates. We propose that Si-based defence operates in wheat via tolerance either in addition or as an alternative to resistance-based defence" |
| Keywords: | Biomass *Herbivory Plant Leaves Poaceae *Silicon Helicoverpa armigera biomechanics plant defence root herbivore silica silicon; |
| Notes: | "MedlineJohnson, Scott N Reynolds, Olivia L Gurr, Geoff M Esveld, Jessica L Moore, Ben D Tory, Gavin J Gherlenda, Andrew N eng Research Support, Non-U.S. Gov't England 2019/08/01 Biol Lett. 2019 Jul 26; 15(7):20190361. doi: 10.1098/rsbl.2019.0361. Epub 2019 Jul 31" |
