Control of Arabidopsis flower and seed development by the homeotic gene APETALA2.
APETALA2 (AP2) plays a central role in the establishment of the floral meristem, the specification of floral organ identity, and the regulation of floral homeotic gene expression in Arabidopsis. We show here that in addition to its functions during flower development, AP2 activity is also required during seed development. We isolated the AP2 gene and found that it encodes a putative nuclear protein that is distinguished by an essential 68-amino acid repeated motif, the AP2 domain. Consistent with its genetic functions, we determined that AP2 is expressed at the RNA level in all four types of floral organs--sepals, petals, stamens, and carpels--and in developing ovules. Thus, AP2 gene transcription does not appear to be spatially restricted by the floral homeotic gene AGAMOUS as predicted by previous studies. We also found that AP2 is expressed at the RNA level in the inflorescence meristem and in nonfloral organs, including leaf and stem. Taken together, our results suggest that AP2 represents a new class of plant regulatory proteins that may play a general role in the control of Arabidopsis development.
Jofuku
K D
KD
Sinsheimer Laboratories, Department of Biology, University of California, Santa Cruz 95064.
den Boer
B G
BG
Van Montagu
M
M
Okamuro
J K
JK
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D010940:Plant Proteins; D012639:Seeds / Q000254:growth & development*
C499534:APETALA2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins