Photoresponses of transgenic Arabidopsis overexpressing the fern Adiantum capillus-veneris PHY1.
The phytochrome gene (PHY1) cDNA from the fern Adiantum capillus-veneris encodes an amino acid sequence that shows equal similarity (50-60%) to all five Arabidopsis phytochromes (PHYA-E). The A. capillus-veneris PHY1 cDNA was transformed into Arabidopsis ecotype Landsberg erecta to investigate its activity in angiosperms. Three of the resulting lines contained at least 8 times more spectrally active phytochrome than the wild type, indicating that A. capillus-veneris phytochrome can incorporate the chromophore of the host plants. Hypocotyl growth inhibition of these transgenic lines was investigated under red and far-red light. The results indicated dominant negative activity of A. capillus-veneris phy1 on the phytochrome A response in the host plants under continuous far-red light. However, the fern phytochrome did not interfere with the red-light repression of hypocotyl growth mediated by endogenous phytochrome B, and it failed to complement a phyB mutant phenotype. These observations suggest that the phy1 phytochrome molecule is too diverged from those of Arabidopsis to be fully functional.
Okamoto
H
H
Department of Biology, Tokyo Metropolitan University, Japan.
Sakamoto
K
K
Tomizawa
K I
KI
Nagatani
A
A
Wada
M
M
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D009154:Mutation; D010641:Phenotype; D018462:Photobiology; D010834:Phytochrome / Q000235:genetics*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D010834:Phytochrome