Details

Autor(en) / Beteiligte

• Li, S. H.
• Li, Y. M.
• Li, M.
• He, X. R.
• Jiang, W. L.
• Liu, B. B.
• Li, Q. M.

Titel

CO2 Enrichment Improves the Drought Resistance of Cucumber Seedlings by Improving Antioxidant Capacity and Sucrose Metabolism

Ist Teil von

• Russian journal of plant physiology, 2022-12, Vol.69 (6), Article 126

Ort / Verlag

Moscow: Pleiades Publishing

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The global atmospheric CO 2 concentration ([CO 2 ]) has sharply risen due to human activities, and it has reached 410 μmol mol –1 at present. It is expected that the atmospheric [CO 2 ] will reach approximately 550 μmol mol –1 by the middle of the 21st century. The increase in the [CO 2 ] has a certain “fertilizing effect” on plants. On the other hand, climate warming and precipitation reductions caused by the greenhouse effect will lead to expanding arid areas and aggravated drought, which will restrict plant growth and yield. Therefore, studying the potential physiological mechanism and synergistic effects of an enriched [CO 2 ] combined with environmental stress factors has great significance for understanding plant physiological and ecological processes. We investigated the effects of an enriched [CO 2 ] (800 ± 40 μmol mol –1 ) on the antioxidant capacity and sucrose metabolism of cucumber ( Cucumis sativus L. cv. ‘Jinyou No. 35’) seedlings under drought stress (5 or 10% PEG 6000 in nutrient solutions). The results showed that (1) the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced by the enriched [CO 2 ]; the contents of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ), as well as the superoxide anion radical ( ) production rate, in the leaves were reduced; and lipid peroxidation and cytomembrane permeability decreased under drought stress. (2) The enriched [CO 2 ] significantly improved sucrose synthase (SS) activity but decreased sucrose phosphate synthase (SPS) activity under drought stress, resulting in the accumulation of hexose through accelerated sucrose decomposition and inhibited synthesis. Thus, the osmotic potential of cells was reduced, and the water absorption capacity was enhanced. In conclusion, the enriched [CO 2 ] relieved the detrimental effects of drought stress and enhanced the resistance of cucumber plant growth during drought stress through enhanced cellular membrane stability and antioxidative enzyme activities, thus promoting the accumulation of soluble sugar, while the MDA content and accumulation of reactive oxygen species (ROS) were reduced.