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Plant function and evolutionary biology
RESEARCH ARTICLE

High levels of anoxygenic photosynthesis revealed by dual-frequency Fourier photoacoustics in Ailanthus altissima leaves

Vladimir Lysenko https://orcid.org/0000-0003-2379-5611 A * and Tatyana Varduny A
+ Author Affiliations
- Author Affiliations

A Academy of Biology and Biotechnology, Southern Federal University, Botanichesky spusk 7, 344041 Rostov-on-Don, Russia.

* Correspondence to: vs958@yandex.ru

Handling Editor: Da-Yong Fan

Functional Plant Biology - https://doi.org/10.1071/FP21093
Submitted: 31 March 2021  Accepted: 2 March 2022   Published online: 13 April 2022

© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing

Abstract

In contrast to oxygenic photosynthesis, true anoxygenic photosynthesis is not associated with O2 evolution originated from water photolysis but still converts light energy to that of the phosphoanhydride bonds of ATP. In a narrow sense, anoxygenic photosynthesis is mainly known as to be related to the purple and green sulfur bacteria, but in a broad sense, it also occurs in the vascular plants. The portion of photosynthetic water photolysis that is compensated by the processes of O2 uptake (respiration, photorespiration, Mehler cycle, etc.) may be referred to as ‘quasi’ anoxygenic photosynthesis. Photoacoustic method allows for the separate detection of photolytic O2 at frequencies of measuring light about 20–40 Hz, whereas at 250–400 Hz, it detects the photochemical energy storage. We have developed a fast-Fourier transform photoacoustic method enabling measurements of both these signals simultaneously in one sample. This method allows to calculate oxygenic coefficients, which reflect the part of photochemically stored light energy that is used for the water photolysis. We show that the true anoxygenic photosynthesis in Ailanthus altissima Mill. leaves reached very high levels under low light, under moderate light at the beginning of the 1-h period, and at the end of the 40-min period under saturating light.

Keywords: CO2 uptake, cyclic electron transport, photobaric signal, photoinhibitory light conditions, photosystem I, photothermal signal, quantum yield, transpiration kinetics.


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