Gene Details:

• MSU gene ID: LOC_Os03g51030
• RAPdb gene ID: Os03g0719800
• Gene Symbol: PHYA OsPhyA
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• ACO1 expression was controlled mainly by PHYA and phyB, and a histochemical analysis showed that ACO1 expression was localized to the basal parts of leaf sheaths of PHYAphyBphyC seedlings, similar to mature wild-type plants at the heading stage, when internode elongation was greatly promoted.
• Rice is a short-day plant, and we found that mutation in either phyB or phyC caused moderate early flowering under the long-day photoperiod, while monogenic PHYA mutation had little effect on the flowering time.
• The PHYA mutation, however, in combination with phyB or phyC mutation caused dramatic early flowering.
• The seedlings of PHYA mutants grown in continuous far-red light showed essentially the same phenotype as dark-grown seedlings, indicating the insensitivity of PHYA mutants to far-red light.
• The etiolated seedlings of PHYA mutants also were insensitive to a pulse of far-red light or very low fluence red light.
• Interestingly, continuous far-red light induced the expression of CAB and RBCS genes in rice PHYA seedlings, suggesting the existence of a photoreceptor(s) other than PHYA that can perceive continuous far-red light in the etiolated seedlings.
• However, hypocotyl elongation experiments revealed that transgenic seedlings expressing S/A PHYA showed a higher amplitude of the red light response with respect to the inhibition of hypocotyl elongation.
• In addition, the transcription levels of several ethylene- or gibberellin (GA)-related genes were changed in PHYAphyBphyC mutants, and measurement of the plant hormone levels indicated low ethylene production and bioactive GA levels in the PHYAphyBphyC mutants.
• The metabolite profiles indicated high accumulation of amino acids, organic acids, sugars, sugar phosphates, and nucleotides in the leaf blades of PHYA phyB phyC triple mutants, especially in the young leaves, compared with those in the WT.
• A gene for 1-aminocyclopropane-1-carboxylate oxidase (ACO1), which is an ethylene biosynthesis gene contributing to internode elongation, was up-regulated in PHYAphyBphyC seedlings.
• We demonstrate that ethylene induced internode elongation and ACO1 expression in PHYAphyBphyC seedlings but not in the wild type and that the presence of bioactive GAs was necessary for these effects.
• Moreover, phyB and PHYA can affect Ghd7 activity and Early heading date1 (a floral inducer) activity in the network, respectively.
• Although PHYAphyBphyC phytochrome-null mutants in rice (Oryza sativa) have morphological changes and exhibit internode elongation, even as seedlings, it is unknown how phytochromes contribute to the control of internode elongation.
• Transgenic tobacco plants expressing either wild-type or S/A PHYA showed similar phenotypic alterations, including dwarfism and dark-green leaves.
• Distinct metabolic profiles between PHYA phyB phyC triple mutants and the wild type (WT), as well as those between young and mature leaf blades, could be clearly observed by principal component analysis (PCA).
• OsPhyA modulates rice flowering time mainly through OsGI under short days and Ghd7 under long days in the absence of phytochrome B.
• These results indicated that OsPhyA influences flowering time mainly by affecting the expression of OsGI under SD and Ghd7 under LD when phytochrome B is absent.
• We also demonstrated that far-red light delays flowering time via both OsPhyA and OsPhyB.

Function-related keywords:

• sheath ,  flower ,  seedling ,  ga ,  phosphate ,  flowering-time ,  ethylene ,  floral ,  heading-date ,  gibberellin ,  leaf ,  dwarf

Literature:

• Isolation and characterization of rice phytochrome A mutants .  DOI:  10.1105/tpc.13.3.521 ;  PMID:  11251094
• Molecular dissection of the roles of phytochrome in photoperiodic flowering in rice .  DOI:  10.1104/pp.111.181792 ;  PMID:  21880933
• The multiple contributions of phytochromes to the control of internode elongation in rice .  DOI:  10.1104/pp.111.184861 ;  PMID:  21911595
• Serine-to-alanine substitutions at the amino-terminal region of phytochrome A result in an increase in biological activity .  DOI:  10.1101/gad.6.12a.2364 ;  PMID:  1459458
• Cryptochrome and phytochrome cooperatively but independently reduce active gibberellin content in rice seedlings under light irradiation .  DOI:  10.1093/pcp/pcs097 ;  PMID:  22764280
• Rice JASMONATE RESISTANT 1 is involved in phytochrome and jasmonate signalling .  DOI:  10.1111/j.1365-3040.2008.01790.x ;  PMID:  18266905
• The HMG-I/Y protein PF1 stimulates binding of the transcriptional activator GT-2 to the PHYA gene promoter .  DOI:  10.1046/j.1365-313x.1999.00440.x ;  PMID:  10363369
• Phytochromes are the sole photoreceptors for perceiving red/far-red light in rice .  DOI:  10.1073/pnas.0907378106 ;  PMID:  19706555
• Distinct and cooperative functions of phytochromes A, B, and C in the control of deetiolation and flowering in rice .  DOI:  10.1105/tpc.105.035899 ;  PMID:  16278346
• Comprehensive metabolite profiling of phyA phyB phyC triple mutants to reveal their associated metabolic phenotype in rice leaves .  DOI:  10.1016/j.jbiosc.2009.03.010 ;  PMID:  19619864
• OsPhyA modulates rice flowering time mainly through OsGI under short days and Ghd7 under long days in the absence of phytochrome B .  DOI:  10.1007/s11103-016-0474-7 ;  PMID:  27039184
• Transcriptional and post-transcriptional regulation of heading date in rice .  DOI:  10.1111/nph.17158 ;  PMID:  33341945

Related News:

Gene Resources:

• NCBI ID: AB109891
• UniProt accessions:

Sequences: