Premium
Temporal separation of two components of phytochrome action
Author(s) -
WHITELAM G. C.,
JOHNSON C. B.
Publication year - 1981
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1981.tb00834.x
Subject(s) - phytochrome , sinapis , sowing , nitrate reductase , germination , fluence , irradiance , nitrate , botany , chemistry , biology , biophysics , horticulture , red light , optics , physics , ecology , ion , organic chemistry , brassica
In germinating seedlings of Sinapis alba nitrate reductase activity as assayed in vivo becomes accessible to phytochrome control between 15 and 17 h after sowing. Phytochrome operates via the high irradiance reaction to control nitrate reductase activity in the period 15 to 20 h after sowing. Both continuous red light and far‐red light elicit this response with a strong fluence rate dependency being apparent in each case. The induction of nitrate reductase activity by light pulses at 20 h after sowing is greatly influenced by red light pre‐treatments (operating through phytochrome) given between 0 and 15 h after sowing. Low fluence rate pre‐treatments reduce the effectiveness of a subsequent pulse to below the level of a dark control whilst high fluence rate pre‐treatments greatly increase the effectiveness of a subsequent pulse.