GA(3)-induced expression of a new functional AAA-ATPase (FsA1) is correlated with the onset of germination in Fagus sylvatica L. seeds (beechnuts).
A full-length cDNA clone, named FsA1, has been isolated from a cDNA library constructed using mRNA from Fagus sylvatica L. dormant seeds (beechnuts). This clone shows high identity with members of the AAA superfamily, for ATPases Associated with a variety of cellular Activities, encoding subunit 8 of the 26S proteasome or Tat binding proteins (TBPs). Direct biochemical evidence supporting Mg(2+)-dependent ATPase activity has been obtained by expressing FsA1 in Escherichia coli as histidine tag fusion protein and using the recombinant protein in the stimulation of ATP hydrolysis. Analysis of the expression of FsA1 transcripts during stratification shows an increase in the presence of gibberellic acid (GA(3)), a treatment that proved to be efficient in breaking dormancy and increasing germination percentages of these seeds, while the addition of paclobutrazol, a well-known GA biosynthesis inhibitor, greatly reduces the expression of the clone. A low level of expression was maintained in the stratification control in H(2)O, where dormancy is slowly released. These results show that this new member of the AAA-ATPase family is up-regulated by GAs and its expression correlated with the germination arise in Fagus sylvatica seeds. The possible function of this protein during the transition from dormancy to germination is discussed.
Lorenzo
Oscar
O
Departamento de Fisiología Vegetal, Centro Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, Plaza de los Doctores de la Reina s/n, 37007 Salamanca, Spain.
Nicolás
Carlos
C
Nicolás
Gregorio
G
Rodríguez
Dolores
D
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D029964:Fagus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects / Q000235:genetics*; D005875:Gibberellins / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011994:Recombinant Proteins / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D014230:Triazoles / Q000494:pharmacology
D018076:DNA, Complementary; D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011994:Recombinant Proteins; D014230:Triazoles; C053370:paclobutrazol; C007842:gibberellic acid; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000251:Adenosine Triphosphatases