1. Sunflower Bark Extract as a Biostimulant Suppresses Reactive Oxygen Species in Salt-Stressed Arabidopsis.
- Author
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Jing Li, Evon, Philippe, Ballas, Stéphane, Trinh, Hoang Khai, Lin Xu, Poucke, Christof Van, Van Droogenbroeck, Bart, Motti, Pierfrancesco, Mangelinckx, Sven, Ramirez, Aldana, Van Gerrewey, Thijs, and Geelen, Danny
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REACTIVE oxygen species ,COMMON sunflower ,BIOACTIVE compounds ,ARABIDOPSIS ,PHOTOSYNTHETIC pigments ,SUNFLOWERS - Abstract
A survey of plant-based wastes identified sunflower (Helianthus annuus) bark extract (SBE), produced via twin-screw extrusion, as a potential biostimulant. The addition of SBE to Arabidopsis (Arabidopsis thaliana) seedlings cultured in vitro showed a dose-dependent response, with high concentrations causing severe growth inhibition. However, when priming seeds with SBE, a small but significant increase in leaf area was observed at a dose of 0.5 g of lyophilized powder per liter. This optimal concentration of SBE in the culturing medium alleviated the growth inhibition caused by 100 mM NaCl. The recovery in shoot growth was accompanied by a pronounced increase in photosynthetic pigment levels and a stabilization of osmotic homeostasis. SBE-primed leaf discs also showed a similar protective effect. SBE mitigated salt stress by reducing the production of reactive oxygen species (ROS) (e.g., hydrogen peroxide) by about 30% and developing more expanded true leaves. This reduction in ROS levels was due to the presence of antioxidative agents in SBE and by activating ROS-eliminating enzymes. Polyphenols, carbohydrates, proteins, and other bioactive compounds detected in SBE may have contributed to the cellular redox homeostasis in salt-stressed plants, thus promoting early leaf development by relieving shoot apical meristem arrest. Sunflower stalks from which SBE is prepared can therefore potentially be valorized as a source to produce biostimulants for improving salt stress tolerance in crops. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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