Abstract
Phytochrome is a plant regulatory photoreceptor that mediates red light effects on a wide variety of physiological and molecular responses. DNA blot analysis indicates that the Arabidopsis thaliana genome contains four to five phytochrome-related gene sequences. We have isolated and sequenced cDNA clones corresponding to three of these genes and have deduced the amino acid sequence of the full-length polypeptide encoded in each case. One of these proteins (phyA) shows 65-80% amino acid sequence identity with the major, etiolated-tissue phytochrome apoproteins described previously in other plant species. The other two polypeptides (phyB and phyC) are unique in that they have low sequence identity (approximately 50%) with each other, with phyA, and with all previously described phytochromes. The phyA, phyB, and phyC proteins are of similar molecular mass, have related hydropathic profiles, and contain a conserved chromophore attachment region. However, the sequence comparison data indicate that the three phy genes diverged early in plant evolution, well before the divergence of the two major groups of angiosperms, the monocots and dicots. The steady-state level of the phyA transcript is high in dark-grown A. thaliana seedlings and is down-regulated by light. In contrast, the phyB and phyC transcripts are present at lower levels and are not strongly light-regulated. These findings indicate that the red/far light-responsive phytochrome photoreceptor system in A. thaliana, and perhaps in all higher plants, consists of a family of chromoproteins that are heterogeneous in structure and regulation.
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Claims 9
Claim · model-written summary
The Arabidopsis genome contains four to five phytochrome-related sequences.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianae0 - Outcome
- phytochrome-related gene sequencese0
- Value
- four to fivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the Arabidopsis thaliana genome contains four to five phytochrome-related gene sequences”
Claim · model-written summary
cDNA clones for three phytochrome genes were sequenced and full polypeptides deduced.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Outcome
- cDNA clonese0
- Value
- threee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We have isolated and sequenced cDNA clones corresponding to three of these genes and have deduced the amino acid sequence of the full-length polypeptide encoded in each case.”
t0“Arabidopsis thaliana”
Claim · model-written summary
phyA shares 65-80% amino acid identity with major phytochromes of other plants.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phyAe0
- Outcome
- amino acid sequence identitye0
- Value
- 65-80%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One of these proteins (phyA) shows 65-80% amino acid sequence identity with the major, etiolated-tissue phytochrome apoproteins described previously in other plant species.”
t0“Arabidopsis thaliana”
Claim · model-written summary
phyB and phyC have approximately 50% sequence identity with each other and other phytochromes.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phyB and phyCe0
- Outcome
- sequence identitye0
- Direction
- lowe0
- Value
- approximately 50%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The other two polypeptides (phyB and phyC) are unique in that they have low sequence identity (approximately 50%) with each other, with phyA, and with all previously described phytochromes.”
t0“Arabidopsis thaliana”
Claim · model-written summary
phyA, phyB and phyC have similar mass and hydropathic profiles and a conserved chromophore attachment region.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phyA, phyB, and phyCe0
- Outcome
- similar molecular mass, have related hydropathic profiles, and contain a conserved chromophore attachment regione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The phyA, phyB, and phyC proteins are of similar molecular mass, have related hydropathic profiles, and contain a conserved chromophore attachment region.”
t0“Arabidopsis thaliana”
Claim · model-written summary
The three phy genes diverged before monocot and dicot divergence.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phy genese0
- Outcome
- diverged early in plant evolutione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the three phy genes diverged early in plant evolution, well before the divergence of the two major groups of angiosperms, the monocots and dicots.”
t0“Arabidopsis thaliana”
Claim · model-written summary
phyA transcript is high in dark-grown seedlings and down-regulated by light.
- Taxon
- A. thalianaArabidopsis thalianae0
- Organ / stage
- seedlingse0
- Treatment
- lighte0
- Gene
- phyAe0
- Outcome
- steady-state level of the phyA transcripte0
- Direction
- down-regulatede0
- Comparator
- dark-growne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The steady-state level of the phyA transcript is high in dark-grown A. thaliana seedlings and is down-regulated by light.”
Claim · model-written summary
phyB transcript is at a lower level and is not strongly light-regulated.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phyBe0
- Outcome
- transcriptse0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the phyB and phyC transcripts are present at lower levels and are not strongly light-regulated.”
t0“Arabidopsis thaliana”
Claim · model-written summary
phyC transcript is at a lower level and is not strongly light-regulated.
- Taxon
- Arabidopsis thalianaArabidopsis thalianat0
- Gene
- phyCe0
- Outcome
- transcriptse0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the phyB and phyC transcripts are present at lower levels and are not strongly light-regulated.”
t0“Arabidopsis thaliana”
The same questions in other papers
light · molecular: expression · Arabidopsis thaliana (thale cress)Positive and negative results
14 papers in the same direction as this paper · 32 in the opposite direction
- positive
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