Enhanced chloroplastic generation of H2O2 in stress‐resistant Thellungiella salsuginea in comparison to Arabidopsis thaliana. Issue 3 (5th August 2014)

• Record Type: Journal Article
• Authors: Wiciarz, Monika; Gubernator, Beata; Kruk, Jerzy; Niewiadomska, Ewa
• Is Part Of: Physiologia plantarum. Volume 153:Issue 3(2015:Mar.)
• Page Start: 467
• Page End: 476
• Publication Date: 2014-08-05
• Subjects: Plant physiology -- Periodicals; 571.2
• DOI: 10.1111/ppl.12248
• Languages: English
• ISSNs: 0031-9317

Abstract

<abstract abstract-type="main" id="ppl12248-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="ppl12248-para-0001">In order to find some basis of salinity resistance in the chloroplastic metabolism, a halophytic <italic>Thellungiella salsuginea</italic> was compared with glycophytic <italic>Arabidopsis thaliana</italic>. In control <italic>T.s.</italic> plants the increased ratios of chlorophyll <italic>a</italic>/<italic>b</italic> and of fluorescence emission at 77 K (F<sub>730</sub>/F<sub>685</sub>) were documented, in comparison to <italic>A.t.</italic>. This was accompanied by a higher Y<sub>II</sub> and lower NPQ (non‐photochemical quenching) values, and by a more active PSI (photosystem I). Another prominent feature of the photosynthetic electron transport (PET) in <italic>T.s.</italic> was the intensive production of H<sub>2</sub>O<sub>2</sub> from PQ (plastoquinone) pool. Salinity treatment (0.15 and 0.30 <italic>M</italic> NaCl for <italic>A.t.</italic> and <italic>T.s.</italic>, respectively) led to a decrease in ratios of chl <italic>a</italic>/<italic>b</italic> and F<sub>730</sub>/F<sub>685</sub>. In <italic>A.t.</italic>, a salinity‐driven enhancement of Y<sub>II</sub> and NPQ was found, in association with the stimulation of H<sub>2</sub>O<sub>2</sub> production from PQ pool. In contrast, in salinity‐treated <italic>T.s.</italic>, these variables were similar as in controls. The intensive H<sub>2</sub>O<sub>2</sub> generation was accompanied by a high activity of PTOX (plastid terminal oxidase), whilst inhibition of this enzyme led to an increased H<sub>2</sub>O<sub>2</sub> formation. It is hypothesized, that the intensive H<sub>2</sub>O<sub>2</sub> generation from PQ pool might be an important element of stress preparedness in <italic>Thellungiella</italic> plants. In control <italic>T.s.</italic> plants, a higher activation state of carboxylase ribulose‐1, 5‐bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) was also documented in concert with the attachment of Rubisco activase (RCA) to the thylakoid membranes. It is supposed, that a closer contact of RCA with PSI in <italic>T.s.</italic> enables a more efficient Rubisco activation than in <italic>A.t.</italic></p> </abstract>