Ecological interactions affecting the evolutionof plant mating systems: Current research and future directions
Stephenson, Andrew , Kariyat, Rupesh , Mena-Ali, Jorge , De Moraes, Consuelo , Mescher, Mark .
Interrelationships among inbreeding, the inducible defense system, and herbivory in horsenettle (Solanum carolinense).
Previous studies have shown that horsenettle exhibits low levels of inbreeding depression under greenhouse conditions but very high levels of inbreeding depression under field conditions due, in large part, to greater herbivory on inbred plants. Consequently, we examined the effects of inbreeding on the expression of the constitutive and inducible defenses of horsenettle. In greenhouse and laboratory studies, ramets of inbred and outbred plants from multiple families were subjected to caterpillar damage by Manduca sexta or left undamaged. From these plants we (a) examined the effects of inbreeding and herbivory on the expression of genes in the herbivore defense pathways using microarrays, (b) collected volatile organic compounds (which are known in other species to attract herbivores and their enemies); (c) collected and analyzed the levels of jasmonic acid (JA) and salicylic acid (SA) and other phytohormones known to be involved in the inducible chemical defenses of plants; and (d) counted the number of trichomes and spines produced on the leaves and internodes. In the field and greenhouse, we examined the attraction of herbivores and predaceous insects to undamaged and herbivore damaged plants. Our data (ranging from patterns of gene expression through hormonal and volatile signaling to behavioral assays of herbivores, predators and parasitoids) all show a consistent pattern indicating that the constitutive and inducible defenses of host plants are disrupted by inbreeding, and that these differences have pronounced consequences for resistance to herbivores and fitness under field conditions.
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Website of presenting author
1 - Pennsylvania State University, Department Of Biology, 208 MUELLER LAB, UNIVERSITY PARK, PA, 16802, USA
2 - The Pennsylvania State University, Plant Biology, 208 Mueller Lab, Dept Of Biology, State College, PA, 16801, USA
3 - Franklin & Marshall College, Department Of Biology, PO Box 3003, Lancaster, PA, 17604-3003, USA
4 - Pennsylvania State University, Entomology, University Park, PA, 16802, USA
organic volatile compounds
Presentation Type: Symposium or Colloquium Presentation
Location: Delaware D/Hyatt
Date: Tuesday, July 10th, 2012
Time: 3:45 PM