Interchloroplast communications in Chara are suppressed under the alkaline bands and are relieved after the plasma membrane excitation.

Autor: Bulychev AA; Department of Biophysics, Faculty of Biology, Moscow State University, 119991 Moscow, Russia. Electronic address: bulychev@biophys.msu.ru., Krupenina NA; Department of Biophysics, Faculty of Biology, Moscow State University, 119991 Moscow, Russia.
Jazyk: angličtina
Zdroj: Bioelectrochemistry (Amsterdam, Netherlands) [Bioelectrochemistry] 2019 Oct; Vol. 129, pp. 62-69. Date of Electronic Publication: 2019 May 13.
DOI: 10.1016/j.bioelechem.2019.05.006
Abstrakt: Immobile chloroplasts in Chara internodal cells release photometabolites into the streaming cytoplasm that distributes the exported solutes and provides metabolic connectivity between spatially remote plastids. The metabolite transmission by fluid flow is evident from chlorophyll fluorescence changes in shaded chloroplasts upon local illumination applied upstream of the analyzed area. The connectivity correlates with the pH pattern on cell surface: it is strong in cell regions with high H + -pump activity and is low in regions featuring large passive H + influx (OH - efflux). One explanation for low connectivity under the alkaline bands is that H + influx lowers the cytoplasmic pH, thus retarding metabolic conversions of solutes carried by the microfluidic transporter. The cessation of H + influx across the plasma membrane by eliciting the action potential and by adding NH 4 Cl into the medium greatly enhanced the amplitude of cyclosis-mediated fluorescence transients. The transition from latent to the transmissive state after the dark pretreatment was paralleled by the temporary increase in chlorophyll fluorescence, reflecting changes in photosynthetic electron transport. It is proposed that the connectivity between distant chloroplasts is controlled by cytoplasmic pH.
(Copyright © 2019. Published by Elsevier B.V.)
Databáze: MEDLINE
Externí odkaz: