ISSN:
1432-2145
Keywords:
Boric acid
;
Pollen
;
Petunia hybrida
;
Temperature discontinuities
;
Protein release
;
Calcium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Energy-driven protein secretion from Petunia hybrida pollen in 10% sucrose solution shaking culture does not change markedly with temperature, except over a narrow (6° C) temperature range with a midpoint at 17° C. Over this narrow temperature range, there is a very rapid increase from a low secretion plateau at low temperatures to a plateau of higher secretion at higher temperatures. Addition of calcium ions decreases the overall amount secreted, but does not change the critical temperature where the rapid rise in secretion is observed. Boric acid, when added to the culture, also decreases the overall amount released, but in a different way to calcium. While there is a sharp discontinuity at 17° C as before, the increase in protein release at this temperature is smaller than before. In addition, after a plateau at temperatures higher than 20° C, there is a second sharp increase in secreted protein over another narrow temperature range with a midpoint of 28° C, followed by another plateau at higher temperatures. The effects of calcium and boric acid are additive. The sharp discontinuities in protein release are interpreted in terms of lipid thermotropism in membranes and a boron involvement in the movement of proteins into the extending pollen tube membranes from secretory vesicles.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00190113
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