Open AccessEffects of the Herbicide San 9789 on Photomorphogenic Responses
Author(s) -
Merten Jabben,
Gerald F. Deitzer
Publication year - 1979
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.63.3.481
Subject(s) - phytochrome , hordeum vulgare , photosynthesis , chlorophyll , chloroplast , biology , botany , white light , stimulation , carotenoid , far red , sucrose , poaceae , red light , biochemistry , gene , physics , neuroscience , optics
The herbicide, 4-chloro-5-(methylamino)-2-(alpha,alpha,alpha-trifluoro-m-tolyl)- 3(2H)-pyridazinone (San 9789), an inhibitor that prevents both carotenoid and chlorophyll accumulation and normal chloroplast development in white light, does not affect the physiological effectiveness of phytochrome in dark-and light-grown plants. Red/far red reversibility of growth inhibition, stimulation of anthocyanin synthesis, and stimulation of phenylalanine ammonia-lyase synthesis are not significantly different in plants grown with and without San 9789. Despite the complete absence of photosynthesis, flowering could be induced in the long day plant Hordeum vulgare L. when sucrose was provided to the leaves. Since the nonphotochemical reactions of phytochrome also are not affected by the herbicide, San 9789 may be used as a tool to study the phytochrome system spectrophotometrically in plants grown for relatively long periods under high intensity white light.