Abstract Detail

Ecological Section

Kaczorowski, Rainee [1], Koplovich, Avi [2], Wink, Michael [3], Katzir, Gadi [4], Izhaki, Ido [4], Markman, Shai [2].

The effects of vegetative and floral damage on nectar alkaloid concentrations in Tree Tobacco (Nicotiana glauca) .

Secondary metabolites are known to be important mediators of plant-animal interactions, including those involving legitimate and non-legitimate pollinators that feed on floral nectar. Tree tobacco (Nicotiana glauca) is a worldwide invasive plant found also throughout Israel, where it is often locally pollinated by the Palestine Sunbird (Nectarinia osea). Anabasine and nicotine are alkaloids that can be found throughout all tissues of the plant, serving as a defense against many herbivores. However, as we found in our previous work, these alkaloids can also be found in the floral nectar, potentially affecting pollinators. Both leaf and flower damage in other Nicotiana species has been shown to induce greater alkaloid production in vegetative tissues and leaf herbivory can increase the concentration of alkaloids in floral nectar. In the current study, we addressed the question of whether both corolla piercing by sunbirds and leaf herbivory induce greater production of these alkaloids. Specifically, we focused on the effect of different damage treatments on the alkaloid concentrations in the floral nectar of N. glauca. Replicates of different maternal plants were grown in an outdoor plot. Plants were assigned to one of four different treatments: leaf only damage, flower only damage, leaf and flower damage, or no damage. Leaf damage (to mimic herbivory) was applied to all mature leaves on the plant by rolling a pattern wheel along both sides of the midvein. Flower damage (to mimic nectar robbing by sunbirds) was applied to all open flowers on the plant by piercing the base of the corollas with the beak of a stuffed sunbird. Damage treatments were applied to all plants in a replicate within a few hours and nectar was sampled approximately 24 hours after the treatment was applied. Results of nectar alkaloid analysis by capillary GLC-MS will be presented and discussed. Sunbird pollinator responses will be investigated in future studies using the alkaloid concentrations found in the present study.

Broader Impacts:

1 - University of Haifa At Oranim, Dept. Of Biology & Environment, Tivon, N/A, 36006, Israel
2 - University of Haifa at Oranim, Dept. of Biology and Environment, Tivon, 36006, Israel
3 - Heidelberg University, Institute of Pharmacy and Molecular Biotechnology , Im Neuenheimer Feld 364, Heidelberg, D-69120 , Germany
4 - University of Haifa, Dept. of Evolutionary & Environmental Biology, Haifa, 31905, Israel

Keywords:
Nicotiana glauca
alkaloids
nectar robbing
floral nectar
damage
herbivory
GLC-MS.

Presentation Type: Oral Paper:Papers for Sections
Session: 41
Location: Newberry/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 9:30 AM
Number: 41003
Abstract ID:522
Candidate for Awards:None