| Title: | Effects of insect herbivory on induced chemical defences and compensation during early plant development in Penstemon virgatus |
| Address: | "Department of Ecology and Evolutionary Biology and University of Colorado Museum, University of Colorado, Campus Box 334, Boulder CO 80309-0334, USA. quintero.carolina@gmail.com" |
| ISSN/ISBN: | 1095-8290 (Electronic) 0305-7364 (Print) 0305-7364 (Linking) |
| Abstract: | "BACKGROUND AND AIMS: The lack of studies assessing the simultaneous expression of tolerance and resistance traits during seedling development and overall seedling defences as compared with adult plants, in general, constitutes a significant research need that can greatly improve our understanding of overall investment in defences during plant ontogeny. METHODS: Using two seedling and two juvenile stages of the perennial herb Penstemon virgatus (Plantaginaceae) evaluations were made of (a) patterns of investment in constitutive chemical defences [i.e. iridoid glycosides (IGs)], and (b) simultaneous variation in the short-term ability of seedling and juvenile stages to induce resistance traits, measured as induced chemical defences, or tolerance traits, measured as compensatory re-growth following moderate levels of damage by a specialist insect herbivore. KEY RESULTS: Plants were highly defended during most of their transition from seedling to early juvenile stages, reaching a constant approx. 20 % dry weight total IGs. Furthermore, following 30 % above-ground tissue damage, seedlings and juvenile stages were equally able to induce resistance, by raising their IG concentration by approx. 8 %, whereas compensatory re-growth was only achieved at young juvenile but not seedling stages. CONCLUSIONS: Two major trends emerged from this study: (1) in contrast to expected and previously observed trends, in this perennial plant species, seedlings seem to be one of the most well-defended stages as compared with adult ones; (2) high levels of constitutive defences did not limit the ability of young developmental stages to induce resistance following damage, although this response may come with a cost (i.e. decreased compensation) in young seedling stages. Hence, as has been previously demonstrated in few other systems, these results points towards an indirect evidence for a trade-off between tolerance and resistance traits at some, but not all, developmental stages; making them often difficult to detect" |
| Keywords: | Animals Biomass *Herbivory Insecta/*physiology Penstemon/growth & development/*metabolism Seedlings/growth & development/*metabolism Constitutive defences Penstemon virgatus compensation development herbivory induced resistance iridoid glycosides plant on; |
| Notes: | "MedlineQuintero, Carolina Bowers, M Deane eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. England 2013/02/07 Ann Bot. 2013 Aug; 112(4):661-9. doi: 10.1093/aob/mct011. Epub 2013 Feb 5" |
