Class
Article
College
College of Agriculture and Applied Sciences
Department
Plants, Soils, and Climate Department
Faculty Mentor
Bruce Bugbee
Presentation Type
Oral Presentation
Abstract
Phytochrome is a photoreceptor that provides information to a plant about its environment. Its two interconvertible forms are tuned on (Pfr) or off (Pr) depending on the quality of light. The ratio of active phytochrome to total phytochrome (also known as phytochrome photo-equilibrium or PPE) is predicted by measurements of spectral distribution and weighting factors published by Sager et al. (1988), Gardner and Graceffo (1982), Kelly and Lagarias (1985) or Lagarias et al. (1987). This estimation is often well correlated with plant morphology under a spectral distribution that only changes quantities of far-red. However, it is unreliable when changing ratios of the rest of the spectrum. This may be the result of several factors: 1) the weighting factors can vary among studies. 2) The values are primarily for phytochrome-A in oats. 3) There are interactions among photoreceptors. 4) Weighting factors come from estimations of phytochrome conversions in etiolated tissue. Chlorophyll in leaf tissue means that phytochrome is not exposed to the incident radiation above the leaf. Instead, phytochrome perceives a spectral distribution enriched in green and far-red. Our data indicate that the estimation of PPE in green leaves is improved by multiplying the spectral distribution by leaf transmission, then applying the weighting factors to the transmitted spectra.
Location
Room 155
Start Date
4-10-2019 1:30 PM
End Date
4-10-2019 2:45 PM
Included in
A Revised Method for Calculating Phytochrome Photo-Equilibrium
Room 155
Phytochrome is a photoreceptor that provides information to a plant about its environment. Its two interconvertible forms are tuned on (Pfr) or off (Pr) depending on the quality of light. The ratio of active phytochrome to total phytochrome (also known as phytochrome photo-equilibrium or PPE) is predicted by measurements of spectral distribution and weighting factors published by Sager et al. (1988), Gardner and Graceffo (1982), Kelly and Lagarias (1985) or Lagarias et al. (1987). This estimation is often well correlated with plant morphology under a spectral distribution that only changes quantities of far-red. However, it is unreliable when changing ratios of the rest of the spectrum. This may be the result of several factors: 1) the weighting factors can vary among studies. 2) The values are primarily for phytochrome-A in oats. 3) There are interactions among photoreceptors. 4) Weighting factors come from estimations of phytochrome conversions in etiolated tissue. Chlorophyll in leaf tissue means that phytochrome is not exposed to the incident radiation above the leaf. Instead, phytochrome perceives a spectral distribution enriched in green and far-red. Our data indicate that the estimation of PPE in green leaves is improved by multiplying the spectral distribution by leaf transmission, then applying the weighting factors to the transmitted spectra.