A new homeodomain-leucine zipper gene from Arabidopsis thaliana induced by water stress and abscisic acid treatment.
We report the isolation and characterization of a new homeobox gene from Arabidopsis thaliana using a polymerase chain reaction (PCR) cloning strategy. The full-length cDNA, designated Athb-12, encodes a protein of 235 amino acids. It contains the conserved DNA binding domain and the leucine zipper motif, characteristic of the homeodomain-leucine zipper family of transcription factors. The deduced amino acid sequence of Athb-12 shows over 80% identity to the Arabidopsis Athb-7 in the homeodomain (82%) and the leucine zipper motif (80%) of the proteins. However, outside the homeodomain and the leucine zipper motif, the homology is significantly lower. RNA analysis identified only one 0.96 kb transcript consistent with the size of Athb-12 cDNA. The Athb-12 transcript was detected in stem, leaf, flower and root as well as in seedlings. Treatment with water stress and exogenous abscisic acid (ABA) resulted in the accumulation of Athb-12 mRNA, similar to that of Athb-7. However, the time course of the Athb-12 response to ABA differed from that of Athb-7, suggesting that both genes, in response to ABA, are regulated in different manners. Taken together, these data suggest that Athb-12 and Athb-7 are members of a related gene family involved in the plant's response to water stress.
Lee
Y H
YH
Kumho Life and Environmental Science Laboratory, Kwangju-City, Korea.
Chun
J Y
JY
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D003890:Desiccation; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology*; D005801:Genes, Homeobox / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D018749:RNA, Plant / Q000032:analysis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics*; D014867:Water
D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors; C112532:atHB-12 protein, Arabidopsis; D014867:Water; D000040:Abscisic Acid