Open Access

ARTICLE

Microalgae Improve the Photosynthetic Performance of Rice Seedlings (Oryza sativa L.) under Physiological Conditions and Cadmium Stress

Ekaterina Yotsova¹, Martin Stefanov¹, Georgi Rashkov¹, Margarita Kouzmanova², Anelia Dobrikova¹, Emilia Apostolova^1,*

1 Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
2 Department of Biophysics and Radiobiology, Biological Faculty, Sofia University, Sofia, Bulgaria

* Corresponding Author: Emilia Apostolova. Email:

Phyton-International Journal of Experimental Botany 2022, 91(7), 1365-1380. https://doi.org/10.32604/phyton.2022.020566

Received 30 November 2021; Accepted 19 January 2022; Issue published 14 March 2022

Abstract

The aim of this study was to assess the impact of the microalgae Chlorella vulgaris on the rice seedlings at physiological conditions and under cadmium (Cd) stress. We examined the effects of C. vulgaris in the nutrient solution on rice seedlings grown hydroponically in the presence and the absence of 150 μM CdCl₂, using the low (77 K) temperature and pulse amplitude modulated (PAM) chlorophyll fluorescence, P700 photooxidation measurements, photochemical activities of both photosystems, kinetic parameters of oxygen evolution, oxidative stress markers (MDA, H₂O₂ and proline), pigment content, growth parameters and Cd accumulation. Data revealed that the application C. vulgaris not only stimulates growth and improves the functions of photosynthetic apparatus under physiological conditions, but also reduces the toxic effect of Cd on rice seedlings. Furthermore, the presence of the green microalgae in the nutrient solution of the rice seedlings during Cd exposure, significantly improved the growth, photochemical activities of both photosystems, the kinetic parameters of the oxygen-evolving reactions, pigment content and decreased lipid peroxidation, H₂O₂ and proline content. Data showed that the alleviation of Cd-induced effects in rice seedlings is a result of the Cd sorption by microalgae, as well as the reduced Cd accumulation in the roots and its translocation from the roots to the shoots.

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Keywords

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