| Title: | Molecular constraints on resistance-tolerance trade-offs |
| Author(s): | Mesa JM; Scholes DR; Juvik JA; Paige KN; |
| Address: | "School of Integrative Biology, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, Illinois, 61801, USA. Department of Biology, University of Indianapolis, 1400 East Hanna Avenue, Indianapolis, Indiana, 46227, USA. Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1201 West Gregory Drive, Urbana, Illinois, 61801, USA" |
| ISSN/ISBN: | 0012-9658 (Print) 0012-9658 (Linking) |
| Abstract: | "Plants have numerous mechanisms to cope with the negative effects of herbivory, including plant resistance, structural and chemical traits that reduce damage, and plant tolerance, the ability to compensate for tissues lost. It has been argued that resistance and tolerance represent alternate strategies and thus there should be a trade-off between resistance and tolerance. However, resistance and tolerance are controlled via the same molecular pathway, the oxidative pentose phosphate pathway and the process of endoreduplication. Endoreduplication is the replication of the genome without mitosis, which leads to an increase in cellular chromosome number. Increasing chromosome number and therefore gene copy number provides a means of increasing gene expression that has been shown to enhance compensation following herbivory. By measuring glucosinolate levels and seed production following the removal of apical dominance in genotypes of Arabidopsis thaliana we show that there is a positive association between tolerance and induced chemical defense. Similarly, the direct association between tolerance and resistance is demonstrated by genetically manipulating the endoreduplication pathway. By overexpressing ILP1, a positive regulator of endoreduplication, and thus compensation, we experimentally increased glucosinolate production and tolerance in the Col-0 genotype. We suggest that many herbaceous plants that endoreduplicate (~90%) would show a positive relationship between compensation and chemical defense, given that the molecular pathways are shared in common. We discuss these findings in light of contrasting results on measures of tolerance and resistance, given that the true relationship can be masked by ignoring genetic variation in endoreduplication and the timing of chemical measurement" |
| Keywords: | Arabidopsis/*physiology Genetic Variation Genotype Glucosinolates/*metabolism Herbivory Arabidopsis endoreduplication fitness compensation glucosinolates overcompensation 30 years later oxidative pentose phosphate pathway resistance shikimate acid pathway; |
| Notes: | "MedlineMesa, J Miles Scholes, Daniel R Juvik, John A Paige, Ken N eng 2017/07/18 Ecology. 2017 Oct; 98(10):2528-2537. doi: 10.1002/ecy.1948" |
