Abstract Detail

Ecophysiology

Yongqian, Zhang [1], Griffin-Nolan, Robert [1], Donahue, Leanne [1], Guidi, Michael [1], Hamilton, Jason [1], Melcher, Peter [1].

The effects of herbivory on leaf-level photosynthesis measured on wild tobacco plants.

A broad range of effects of herbivory on photosynthesis as the plant’s main primary metabolic process has been reported. Pioneering studies of herbivore-induced changes in photosynthesis found that the majority of defoliating herbivores cause an increase in photosynthetic activity, whereas mesophyll and phloem feeders, stem borers and gall formers mainly decreased photosynthesis in the remaining plant tissue. Plants also have indirect defenses, such as the production of volatile organic compounds that can facilitate top-down control of herbivore populations by increasing the foraging success of herbivore predators and parasitoids. Abiotic and biotic induced plant responses are not restricted to secondary metabolism, but include changes in various primary metabolic pathways. To investigate these plant-animal interactions, we are measuring leaf-level photosynthetic responses of wild tobacco plants collected from field sites in Arizona and Utah in response to various phytochemicals. Previously, our group showed that these wild tobacco plants respond to herbivory attack with increased photosynthesis from myriad bug herbivory and decreased photosynthesis from Manduca hornworm herbivory. Since these leaf-level photosynthetic measurements take an enormous amount of time, we developed a rapid screening method that allows one to measure variation in PSII electron efficiency in response to chemical treatments on many (up to 96) samples simultaneously using a CF Fluorescence Imaging system (Technologia, UK). We were successful to measure changes in electron efficiency in the leaves of tobacco using two phytochemicals Jasmonic acid (JA) and Salicylic Acid (SA) compared to deionized water and an electron blocker (3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Future work will involve measurements of chemicals extracted and isolated from wild myrid bug and manduca hornworm salivary glands on leaf-level electron transport efficiency and results from these studies will be presented.

Broader Impacts:

1 - Ithaca College, Biology, Center for Natural Sciences, Ithaca, New York, 14850, United States

Keywords:
photosynthesis
electron transport
Imaging
plant-herbivore interactions.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PEP001
Abstract ID:628
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize