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The Photoregulation of Phenylpropnaoid Metabolism and Amino Acid Accumulation in Triticum Aestivum (Var. Fremont)

Wheat (Triticum aestivum L.) grown in controlled environments with a 24-hour photoperiod was analyzed for phenylpropanoid and amino acid metabolites. Discrete spectral environments, including a metal halide, high-pressure sodium and low-pressure sodium lamps, provided both photosynthetically active radiation and phenylpropanoid inducing fluences of light . A greenhouse spectral environment supplemented with fluorescent lamps was also used to culture wheat . All. four spectral envi ronments were used to culture wheat to maturity separately. The activities of phenylalanine and tyrosine ammonia-lyase were photoinduced in wheat tissue obtained from plants grown in the metal halide, high -pressure sodium and greenhouse spectral environments. These enzyme activities are the committed catalytic step in phenylpropanoid biosynthesis and were induced in wheat tissue by fluences of light in the ultraviolet and blue regions of the spectrum. The low-pressure sodium lamp , which does not provide strong irradiance in these wavelengths , produced significantly lower ammonia-lyase activities than were observed in wheat grown within the metal halide , high-pressure sodium, or greenhouse spectral environments. These effects were not caused by phytochrome, since calculation of PfrfPtotal for the low-pressure sodium lamp was higher than the ratio obtained from metal halide or high-pressure sodium lamps. Lignin was also significantly reduced in wheat grown with low-pressure sodium lamps . Several essentialamino acids were in lower molar concentration in protein from wheat grown under low-pressure sodium lamps. However, phenylalanine and tyrosine were in significantly higher concentration in wheat grain produced in this spectral environment, and amino acid concentrations of wheat cultured with the low-pressure sodium lamp are regarded as a direct result of the spectral properties of this light source.

Identiferoai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-4441
Date01 May 1983
CreatorsGuerra, Daniel J.
PublisherDigitalCommons@USU
Source SetsUtah State University
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceAll Graduate Theses and Dissertations
RightsCopyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact Andrew Wesolek (andrew.wesolek@usu.edu).

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