Abstract Detail



Molecular Ecology

Mesa , Joshua Miles [1], Paige, Ken [2].

Endopolyploidy as a Driver of Plant Tolerance and Resistance.

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 tradeoff 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 (replication of the genome without mitosis). Our previous studies have shown a causal link between mammalian herbivory, tolerance, and chemical defense in Arabidopsis thaliana; driven by the process of endoreduplication. Removal of the apical meristem by mammalian herbivores lowers auxin, which triggers entry into the endocycle. Increasing chromosome number through endoreduplication, and therefore gene copy number, provides a means of increasing gene expression promoting rapid regrowth rates, higher defensive chemistry and enhanced fitness. Here we assess whether insect leaf-feeding elicits the same compensatory response as the removal of apical dominance. Insect-feeding has been shown to down-regulate auxin production, which should trigger endoreduplication. Results of this study support this contention; insect leaf-feeding by Trichoplusia ni elicited a compensatory response similar to that of mammalian herbivores - an ecotype-specific response dependent upon the level of endoreduplication.


1 - University of Arizona, Ecology and Evolutionary Biology, BioSciences West room 329, 1041 E. Lowell St., Tuscon, AZ, 85719, USA
2 - University of Illinois, Animal Biology, 505 S. Goodwin, Urbana, Il, 61801, USA

Keywords:
Fitness Compensation
Resistance
Tolerance
Endoreduplication.

Presentation Type: Oral Paper
Number: 0007
Abstract ID:463
Candidate for Awards:None


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