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Phytochrome A resets the circadian clock and delays tuber formation under long days in potato
Author(s) -
Yanovsky Marcelo J.,
Izaguirre Miriam,
Wagmaister Javier A.,
Gatz Christiane,
Jackson Stephen D.,
Thomas Brian,
Casal Jorge J.
Publication year - 2000
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2000.00775.x
Subject(s) - phytochrome , far red , circadian rhythm , photoperiodism , phytochrome a , biology , transgene , circadian clock , reset (finance) , red light , arabidopsis thaliana , mutant , microbiology and biotechnology , botany , genetics , neuroscience , gene , financial economics , economics
Summary Transgenic potatoes ( Solanum tuberosum ) with either increased (sense transformants) or reduced (antisense transformants) phytochrome A (phyA) levels were used, in combination with specific light treatments, to investigate the involvement of phyA in the perception of signals that entrain the circadian clock. Far‐red or far‐red plus red light treatments given during the night reset the circadian rhythm of leaf movements in wild‐type plants and phyA over‐expressors, but had little effect in phyA under‐expressors. Far‐red light was also able to reset the rhythm of leaf movement in wild‐type Arabidopsis thaliana but was not effective in mutants without phyA. Blue light was necessary to reset the rhythm in phyA‐deficient potato plants. Resetting of the rhythm by far‐red plus red light was only slightly affected in transgenic plants with reduced levels of phytochrome B. The production of tubers was delayed by day extensions with far‐red plus red light, but this effect was reduced in transgenic lines deficient in phyA. We conclude that phyA is involved in resetting the circadian clock controlling leaf movements and in photoperiod sensing in light‐grown potato plants.