Bossen ME, Dassen HH, Kendrick RE, Vredenberg WJ. The role of calcium ions in phytochrome-controlled swelling of etiolated wheat (Triticum aestivum L.) protoplasts.
PLANTA 1988;
174:94-100. [PMID:
24221423 DOI:
10.1007/bf00394879]
[Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/1987] [Accepted: 09/28/1987] [Indexed: 06/02/2023]
Abstract
Protoplasts from dark-grown wheat (Triticum aestivum L.) maintained at a constant osmotic potential at 22°C, were found to swell upon red irradiation (R) and the effect was negated by subsequent far-red light (FR), indicating phytochrome involvement. Swelling only occurred when Ca(2+) ions were present in the surrounding medium, or were added within 10 min after R. Furthermore, Mg(2+), Ba(2+) or K(+) could not replace this requirement for Ca(2+). The presence of K(+) did not enhance the Ca(2+)-dependent swelling response. When the Ca(2+)-ionophore A 23187 was added to the medium, protoplasts swelled in the dark to the same extent as after R. Both the Ca(2+)-channelblocker Verapamil and La(3+) inhibited R-induced swelling. It is proposed that R causes the opening of Ca(2+)-channels in the plasma membrane. Boyle-van't Hoff analyses of protoplast volume after R and FR are consistent with the conclusion that R irradiation causes changes in membrane properties.
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