Abstract Detail

Physiology & Ecophysiology

Kriss, Tayler J [1], Maricle, Brian R. [2].

Photosynthetic action spectra of etiolated beans during greening.

How varying wavelengths of light drive photosynthesis has not been investigated during the period when young plants are transitioning from an etiolated state to a green state. In this study, photosynthetic rates of young bean plants were analyzed in light with wavelengths of 350 nm to 750 nm. Isolated thylakoids were analyzed spectrophotometrically with an artificial electron acceptor (DCIP, a Hill reagent) to measure the light reactions of photosynthesis. Monochromatic light was supplied by a spectrophotometer, and samples were illuminated at a specific wavelength for five minutes. Another spectrophotometer measured difference in absorbance as the Hill reagent in solution was reduced by electron transfer in the light reactions of photosynthesis. Plants were germinated in the dark for 14 days and then moved into sunlight. Analysis was done at 0, 3, 7, and 21 days of light exposure. These were the first action spectra of photosynthesis measured during greening in etiolated seedlings. Blue and red wavelengths of light were most effective at driving the light reactions of photosynthesis, but not during the initial few days of greening. Photosynthetic rates, calculated by use of the Hill reaction, were minimal until 7 days of sunlight exposure, but were evident thereafter. This work shows spectrophotometers can be used as an illuminating source to measure action spectra of photosynthesis. This allows action spectra to be constructed for small-scale reactions without the need for sophisticated equipment.

1 - Fort Hays State University, Department of Biological Sciences , 1904 Fort Street, Hays , Kansas , 67601, United States
2 - Fort Hays State University, Department Of Biological Sciences, 600 Park St., Hays, KS, 67601-4099, USA

Keywords:
Photosynthetic action spectra
photochemistry.

Presentation Type: Poster
Session: P, Physiology & Ecophysiology
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPE003
Abstract ID:193
Candidate for Awards:Developmental and Structural Section best poster