Comparative photosynthetic responses of Norway spruce and Scots pine seedlings to prolonged water deficiency.

Autor: Zlobin IE; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia. Electronic address: ilya.zlobin.90@mail.ru., Kartashov AV; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia., Pashkovskiy PP; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia., Ivanov YV; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia., Kreslavski VD; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia; Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russia., Kuznetsov VV; K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia.
Jazyk: angličtina
Zdroj: Journal of photochemistry and photobiology. B, Biology [J Photochem Photobiol B] 2019 Dec; Vol. 201, pp. 111659. Date of Electronic Publication: 2019 Oct 30.
DOI: 10.1016/j.jphotobiol.2019.111659
Abstrakt: Stressors of different natures, including drought stress, substantially compromise the ability of plants to effectively and safely utilize light energy. We investigated the influence of water stress on the photosynthetic processes in Picea abies and Pinus sylvestris, two species with contrasting drought sensitivities. Spruce and pine seedlings were exposed to polyethylene glycol 6000-induced water deficits of different intensities and durations. The maintenance of photosystem I (PSI) oxidation in spruce required increased photosynthetic control and led to the increased reduction of the plastoquinone pool, which was not the case in pine seedlings. As a result of increased excitation pressure, photosystem II (PSII) inactivation was observed in spruce plants, whereas in pine, the decreased PSII photochemistry was likely due to sustained non-photochemical quenching. Downregulation of PSII photochemistry and maintenance of PSI in an oxidized state were linked with the prevention of oxidative stress, even under severe water deficit. The decreased photosynthetic pigment content and photosynthetic gene expression suggested the coordinated downregulation of photosynthetic apparatus components under water stress to reduce light energy absorption. In summary, the observed adaptative mechanisms of pine and spruce to water stress may be similar to the well-studied adaptative mechanisms to winter stress, which may indicate the universality of protective mechanisms under various stresses in conifers.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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