The Arabidopsis Athb-2 and -4 genes are strongly induced by far-red-rich light.
The isolation and characterization of the Athb-2 gene, which codes for a HD-Zip protein in Arabidopsis thaliana is reported. Interestingly, Southern analysis has established that the Arabidopsis genome contains sequences which are highly related to the Athb-2 HD-Zip coding region. One of these genes, designated Athb-4, has been cloned and partially sequenced. Amino acid sequence comparison revealed that Athb-2 and -4 are members of a small family of HD-Zip related proteins. Athb-2 mRNA analysis showed that this gene is expressed during the vegetative and reproductive phases of plant growth. A significant increment in the amount of Athb-2 transcripts was observed in flowering plants. A higher steady-state level of the Athb-2 mRNA was also found in dark-adapted plants. Remarkably, far-red-rich light treatment of Arabidopsis plants results in a rapid and strong induction of the Athb-2 expression. This light treatment also induces the accumulation of Athb-4 transcripts, suggesting a similar role for the two members of this HD-Zip family.
Carabelli
M
M
Centro di studio per gli Acidi Nucleici, Università di Roma La Sapienza, Italy.
Sessa
G
G
Baima
S
S
Morelli
G
G
Ruberti
I
I
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000528:radiation effects; D005801:Genes, Homeobox; D017343:Genes, Plant / Q000528:radiation effects*; D018398:Homeodomain Proteins; D016350:Leucine Zippers / Q000235:genetics; D008027:Light; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C069386:HB-2 protein, Arabidopsis; D018398:Homeodomain Proteins; D010940:Plant Proteins; D004247:DNA