Dormancy-associated gene expression in pea axillary buds. Cloning and expression of PsDRM1 and PsDRM2.
Pea (Pisum sativum L. cv. Alaska) axillary buds can be stimulated to cycle between dormant and growing states. Dormant buds synthesize unique proteins and are as metabolically active as growing buds. Two cDNAs, PsDRM1 and PsDRM2, were isolated from a dormant bud library. The deduced amino acid sequence of PsDRM1 (111 residues) is 75% identical to that of an auxin-repressed strawberry clone. PsDRM2 encodes a putative protein containing 129 residues, which includes 11 repeats of the sequence [G]-GGGY[H][N] (the bracketed residues may be absent). PsDRM2 is related to cold- and ABA-stimulated clones from alfalfa. Decapitating the terminal bud rapidly stimulates dormant axillary buds to begin growing. The abundance of PsDRM1 mRNA in axillary buds declines 20-fold within 6 h of decapitation; it quickly reaccumulates when buds become dormant again. The level of PsDRM2 mRNA is about three fold lower in growing buds than in dormant buds. Expression of PsDRM1 is enhanced in other non-growing organs (roots >> root apices; fully-elongated stems > elongating stems), and thus is an excellent "dormancy" marker. In contrast, PsDRM2 expression is not dormancy-associated in other organs.
Department of Biological Sciences, Northern Illinois University 60115, USA. stafstrom@niu.edu
J P
JP
Stafstrom
B D
BD
Ripley
M L
ML
Devitt
B
B
Drake
D000595:Amino Acid Sequence; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
C113931:DRM1 protein, Pisum sativum; C113932:DRM2 protein, Pisum sativum; D010940:Plant Proteins