skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2

Authors:
 [1];  [1];  [2];  [3]; ORCiD logo [1]
  1. Department of Molecular and Cellular Biology, University of California, Davis CA 95616 USA
  2. Department of Biology, Duke University, Durham NC 27708 USA
  3. CSIRO National Research Collections Australia, Australian National Herbarium, Canberra ACT 2601 Australia
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1401047
Grant/Contract Number:
FG02-09ER16117
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
New Phytologist
Additional Journal Information:
Journal Volume: 214; Journal Issue: 3; Related Information: CHORUS Timestamp: 2017-10-20 16:10:40; Journal ID: ISSN 0028-646X
Publisher:
Wiley-Blackwell
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Rockwell, Nathan C., Martin, Shelley S., Li, Fay-Wei, Mathews, Sarah, and Lagarias, John Clark. The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2. United Kingdom: N. p., 2017. Web. doi:10.1111/nph.14422.
Rockwell, Nathan C., Martin, Shelley S., Li, Fay-Wei, Mathews, Sarah, & Lagarias, John Clark. The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2. United Kingdom. doi:10.1111/nph.14422.
Rockwell, Nathan C., Martin, Shelley S., Li, Fay-Wei, Mathews, Sarah, and Lagarias, John Clark. Fri . "The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2". United Kingdom. doi:10.1111/nph.14422.
@article{osti_1401047,
title = {The phycocyanobilin chromophore of streptophyte algal phytochromes is synthesized by HY2},
author = {Rockwell, Nathan C. and Martin, Shelley S. and Li, Fay-Wei and Mathews, Sarah and Lagarias, John Clark},
abstractNote = {},
doi = {10.1111/nph.14422},
journal = {New Phytologist},
number = 3,
volume = 214,
place = {United Kingdom},
year = {Fri Jan 20 00:00:00 EST 2017},
month = {Fri Jan 20 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1111/nph.14422

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

Save / Share:
  • In early seedling development, far-red-light-induced deetiolation is mediated primarily by phytochrome A (phyA), whereas red-light-induced deetiolation is mediated primarily by phytochrome B (phyB). To map the molecular determinants responsible for this photosensory specificity, we tested the activities of two reciprocal phyA/phyB chimeras in diagnostic light regimes using overexpression in transgenic Arabidopsis. Although previous data have shown that the NH{sub 2}-terminal halves of phyA and phyB each separately lack normal activity, fusion of the NH{sub 2}-terminal half of phyA to the COOH-terminal half of phyB (phyAB) and the reciprocal fusion (phyBA) resulted in biologically active phytochromes. The behavior of these twomore » chimeras in red and far-red light indicates: (i) that the NH{sub 2}-terminal halves of phyA and phyB determine their respective photosensory specificities; (ii) that the COOH-terminal halves of the two photoreceptors are necessary for regulatory activity but are reciprocally interchangeable and thus carry functionally equivalent determinants; and (iii) that the NH{sub 2}-terminal ;halves of phyA and phyB carry determinants that direct the differential light lability of the two molecules. The present findings suggest that the contrasting photosensory information gathered by phyA and phyB through their NH{sub 2}-terminal halves may be transduced to downstream signaling components through a common biochemical mechanism involving the regulatory activity of the COOH-terminal domains of the photoreceptors. 32 refs., 7 figs.« less
  • The amplitude of phototropic curvature to blue light is enhanced by a prior exposure of seedlings to red light. This enhancement is mediated by phytochrome. Fluence-response relationships have been constructed for red-light-induced enhancement in the phytochrome A (phyA) null mutant, the phytochrome B- (phyB) deficient mutant, and in two transgenic lines of Arabidopsis thaliana that overexpress either phyA or phyB. These fluence-response relationships demonstrate the existence of two responses in enhancement, a response in the very-low-to-low-fluence range, and a response in the high-fluence range. Only the response in the high-fluence range is present in the phyA null mutant. In contrast,more » the phyB-deficient mutant is indistinguishable from the wild-type parent in red-light responsiveness. These data indicate that phyA is necessary for the very-low-to-low but not the high-fluence response, and that phyB is not necessary for either response range. Based on these results, the high-fluence response, if controlled by a single phytochrome, must be controlled by a phytochrome other than phyA or phyB. Overexpression of phyA has a negative effect and overexpression of phyB has an enhancing effect in the high fluence range. These results suggest that overexpression of either phytochrome perturbs the function of the endogenous photoreceptor system in unpreditable fashion. 25 refs., 3 figs.« less
  • Using dichromatic radiation, we show that the actions of phytochromes A and B (phyA and phyB) in Arabidopsis thaliana are antagonistic in mediating red and far-red radiation effects on seedling de-etiolation and yet act in a complementary manner to regulate de-etiolation, irrespective of spectral composition. At low phytochrome photoequilibria inhibition of hypocotyl extension was strong, because of the action of a far-red high-irradiance response mediated by phyA. At high phytochrome photoequilibria inhibition of hypocotyl extension was also strong, because of the action of phyB. At intermediate photoequilibria hypocotyl inhibition was less strong. In their natural environment, this dual action willmore » strongly retard hypocotyl growth and promote cotyledon opening and expansion both in open daylight and under dense vegetation. Overlapping action by phyA and phyB will substantially promote de-etiolation in sparse vegetation. The antagonistic and complementary actions of phyA and phyB, therefore, allow the optimum regulation of seedling growth after emergence from the soil.« less
  • The energies of the highest occupied and lowest empty molecular orbitals were calculated for the chromophore groups of the proteins phycocyanin and phycoerythrin. These tetrapyrrole groups on the algal proteins are shown to provide them with the potential of acting as efficient electron donors and acceptors. In addition, the ..pi.. electron charges and bond orders were also computed. 4 figures, 1 table.