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Mechanism of detecting light direction in first positive phototropism in Zea mays L.
Author(s) -
PIENING C. J.,
POFF K. L.
Publication year - 1988
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 - 10.1111/1365-3040.ep11604915
Subject(s) - phototropism , zea mays , gravitropism , mutant , mechanism (biology) , growth regulator , biology , botany , chemistry , biophysics , blue light , physics , optics , agronomy , biochemistry , arabidopsis , quantum mechanics , gene
. The carotenoid content of corn seedlings was reduced by 80–90% with the herbicide SAN 9789 or by using carotenoidless mutants. This caused a decrease in ‘first positive’ phototropism by about 50% without affecting geotropism. This reduction in phototropism is attributed to the decreased light gradient across the albino shoot. Decreased screening should increase the response if a focusing mechanism is used to measure the light gradient, but should decrease the response if a screening mechanism is used. Thus, these data support the hypothesis that screening establishes the light gradient used to measure light direction in ‘first positive’ phototropism.