Auxin-induced delay of abscission: The involvement of calcium ions and protein phosphorylation in bean explants
Poovaiah, B. W. ; Friedmann, M. ; Reddy, A. S. N. ; Rhee, J. K.
Oxford, UK : Blackwell Publishing Ltd
Published 1988
Oxford, UK : Blackwell Publishing Ltd
Published 1988
| ISSN: |
1399-3054
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| Source: |
Blackwell Publishing Journal Backfiles 1879-2005
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| Topics: |
Biology
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| Notes: |
Treatment with Ca2+ channel blockers such as lanthanum chloride and verapamil promoted abscission in pulvinar explants of bean (Phaseolus vulgaris L. ev. Pirate). In addition, auxin-induced delay of abscission was markedly reduced in the presence of Ca2+ channel blockers. In vitro phosphorylation studies were performed using membrane preparations (130000 g pellet) from freshly excised as well as auxintreated and control (minus auxin) pulvinar sections. Auxin-treated sections showed a 66 kDa phosphoprotein as well as Ca2+ -dependent phosphorylation that were not observed in control explants.Coomassie blue stammg of soluble proteins (130000 g supernatent) separated on SDS-PAGE revealed the presence of 62. 55 and 47 kDa polypeptides only in the freshly excised pulvini. However. no distinct changes were observed in soluble protein profile between auxin-treated and control explants. When soluble proteins were phosphorylated in vitro, Ca2+ promoted the phosphorylation of 92, 55. 40 and I7 kDa polypeptides only in freshly excised pulvmi. Ca2+-dependent phosphorylation of soluble proteins was not observed in either the control or auxin-treated explants. In addition. in vivo phosphorylation studies were performed using freshly excised. auxrn-treated and control explants. Freshly excused segments and auxin-treated ex-plants showed similar phosphoproteins, which were different from those observed mcontrol.
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| Type of Medium: |
Electronic Resource
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| URL: |