Photosynthetica 2020, 58(SI):608-621 | DOI: 10.32615/ps.2020.025

Special issue in honour of Prof. Reto J. Strasser – Photosynthetic activity as assessed via chlorophyll a fluorescence suggests a role of potassium channels in root to shoot signaling

O.V. VOITSEKHOVSKAJA¹, V.I. APOLLONOV¹, A.V. MURTUZOVA¹, C.K. RABADANOVA¹, M.A. CHARNYSH², I.V. DROZDOVA³, A.I. BELYAEVA³, O.N. KOVALEVA⁵, I.G. LOSKUTOV⁵, K. PAWLOWSKI⁶, V.V. DEMIDCHIK², E.V. TYUTEREVA¹

¹ Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, Professora Popova 2, 197376 St.-Petersburg, Russia

² Department of Plant Cell Biology and Bioengineering, Biological Faculty, Belarusian State University, Independence Avenue 4, 220030, Minsk, Belarus

³ Laboratory of Ecology of Plant Communities, Komarov Botanical Institute, Russian Academy of Sciences, Professora Popova 2, 197376 St.-Petersburg, Russia

⁵ Department of Genetic Resources of Oat, Barley and Rye, N.I. Vavilov Institute of Plant Genetic Resources (VIR), 44 Bolshaya Morskaya Str., 190000 St.-Petersburg, Russia

⁶ Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden

Potassium is indispensable for plant growth. Recently, a role of K⁺ channels has emerged in sensing and transducing stress and nutrient status. Tetraethylammonium (TEA⁺) is a specific blocker of K⁺ transport and affects K⁺ channel gene expression. Two barley varieties with contrasting salinity tolerance, and a chlorophyll b-less mutant, were grown either in the presence of TEA⁺ alone or combined with NaCl, at two different concentrations of external K⁺ and Ca²⁺, and were analyzed nine days after germination. Chlorophyll a transients monitored via JIP-tests were used to evaluate the state of the photosynthetic machinery. In contrast to reported responses to K⁺ deficiency, TEA⁺ inhibited shoot growth while inducing root growth and increasing photosynthetic performance. Both TEA⁺ and NaCl induced the appearance of negative K-bands in OJIP kinetics and an increase in PI_ABS, indicating a stimulation of photosynthesis by increased sink strength in the context of root to shoot signaling.

Additional key words: chlorina f2; ion content; quaternary ammonium salts; salt stress.

Received: October 30, 2019; Revised: March 12, 2020; Accepted: March 16, 2020; Prepublished online: April 4, 2020; Published: May 28, 2020Show citation