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Microelectrode study of H+ redistribution in characean internodes during long-lasting and prompt responses to environmental cuesстатья
- Авторы: Komarova A.V., Bulychev A.A.
- Сборник: Microelectrodes: Techniques, Structures for Biosensing and Potential Applications (Kin Fong Lei, Ed.)
- Год издания: 2014
- Место издания: Nova Biomedical New York
- Первая страница: 271
- Последняя страница: 292
- Аннотация: This chapter describes applications of pH microelectrodes for electrophysiological studies with internodal cells of Chara corallina. The first example deals with longitudinal profiles of vacuolar pH in relation to variable light environment and self-organization; the second one considers extracellular pH changes in response to localized mechanical injury that mimics the physical impact of pathogens or herbivores. Internodal cells of C. corallina are able to generate under light the functional patterns comprising photosynthetically active and inactive cell regions coordinated with areas of low and high extracellular pH, respectively. Different metabolic and ion transport patterns in these cell regions might affect the operation of H+-transporting systems at the tonoplast and cause uneven distribution of pH in the vacuolar sap. The intracellular pH measurements combined with the method of internal perfusion revealed large spatial variations in longitudinal profiles of the vacuolar pH in illuminated internodes and substantial suppression of these pH variations during prolonged dark adaptation. Apart from intracellular pH measurements, tracking the external pH at the cell surface proved to be an informative tool on variety of processes occurring during plasma membrane electrical excitation, cyclosis, and mechanical stimulation. In particular, the incision of cell wall with a glass micropipette was found to produce rapid localized alkalinization of the apoplast up to 3 pH units. This prompt response apparently serves to cell protection by hardening the cell wall structure. The origin of rapid pH changes was partly clarified by studying mechanically induced pH responses in cells treated with channel blockers and metabolic inhibitors.
- Добавил в систему: Булычев Александр Александрович