The expression of the Athb-8 homeobox gene is restricted to provascular cells in Arabidopsis thaliana.
We have characterized an Arabidopsis homeobox gene coding for a putative DNA binding protein that represents an early marker for vascular development. The full-length cDNA encodes a protein of 833 amino acids that we have designated Athb-8; it contains the conserved DNA binding domain that characterizes the HD-Zip family of transcription factors. RNA analysis showed that the Athb-8 gene is expressed during the vegetative and the reproductive phases of plant growth. A higher steady-state level of the Athb-8 mRNA was found in flowering stem and root. In situ mRNA analysis of Arabidopsis plants demonstrated that Athb-8 expression is restricted to the procambial cells of embryo and developing organs. Moreover, Athb-8-GUS expression was found in single parenchyma cells which are differentiating into tracheary elements in wounded tobacco transgenic plants. Finally, we showed that the auxin, indole-3-acetic acid, which is involved in vascular development and differentiation, modulates the expression of the gene. Taken together, these results suggest that Athb-8 might be a regulator of vascular development in Arabidopsis thaliana.
Baima
S
S
Unità di Nutrizione Sperimentale, Istituto Nazionale della Nutrizione, Rome, Italy.
Nobili
F
F
Sessa
G
G
Lucchetti
S
S
Ruberti
I
I
Morelli
G
G
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000196:embryology / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*
C098015:ATHB-8 protein, Arabidopsis; D029681:Arabidopsis Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors