Incubation of corn coleoptiles with auxin enhances in-vitro fusicoccin binding |
| |
Authors: | P Aducci A Ballio M Marra |
| |
Institution: | (1) Gruppo di Chimica Biologica e Strutturistica Chimica, Facoltà di Scienze, Università di Roma La Sapienza , Città Universitaria, I-00185 Rome, Italy |
| |
Abstract: | Binding of fusicoccin (FC) to microsomal preparations of corn (Zea mays L.) coleoptiles is enhanced after incubation of the tissue with indole-3-acetic acid (IAA). Treatment of the kinetic data according to Scatchard shows that the enhancement is a consequence of an increase in the number of high-affinity FC-binding sites without changes of their KD. The minimal effective concentration of IAA is 10-7 M; above 10-5 M the effect declines. The stimulation is insensitive to protein-synthesis inhibitors (cycloheximide and puromycin). The same effect is observed with the synthetic auxins 2,4-dichlorophenoxyacetic acid and naphtalene-1-acetic acid while it is abolished by the auxin antagonists naphtalene-2-acetic acid and p-chlorophenoxyisobutyric acid. Since the above effect is only observed with intact tissue and not after incubation of IAA with microsomal preparations, a direct interaction of IAA with the FC-binding sites is ruled out and an alternative mechanism must be sought.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- FC
fusicoccin
- 3H]FC
3H-labeled dihydrofusicoccin
- IAA
indole-3-acetic acid
- 1-NAA
naphtalene-1-acetic acid
- 2-NAA
naphtalene-2-acetic acid
- PCIB
p-chlorophenoxyisobutyric acid |
| |
Keywords: | Auxin and fusicoccin Fusicoccin Zea (fusicoccin binding) |
本文献已被 SpringerLink 等数据库收录! |
|