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Phytochrome control of hypocotyl extension in light‐grown Chenopodium rubrum
Author(s) -
Holmes M. G.,
Wagner E.
Publication year - 1981
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1981.tb04492.x
Subject(s) - hypocotyl , phytochrome , photosynthesis , botany , chenopodium , phototropism , biology , biophysics , chemistry , blue light , physics , red light , optics , weed
The regulation of hypocotyl extension in light‐grown Chenopodium rubrum L. seedlings by light analogous to dense vegetation canopy shade has been monitored. Hypocotyl extension was controlled by both the quantity and quality of the actinic light. At the higher of the two background photon fluence rates which were used (10.0 μmol m −2 s −1 in the 400–700 nm waveband), increasing the proportion of phytochrome calculated to exist as Pfr resulted in greater inhibition of growth. At the lower photon fluence rate (1.0 μmol m −2 s −1 in the 400–700 nm waveband), a biphasic response was observed in which minimum inhibition was observed at intermediate photoequilibria. Although photosynthesis was not directly involved in the photomorphogenetic responses, it did play an indirect quantitative role in determining the response.