Antioxidant Enzyme Response of Creeping Bentgrass Clonal Lines with Marine Peptide and Chitosan Oligosaccharide

Abstract

The effect of antioxidant stimulators on low phenolic and high phenolic single seed originating creeping bentgrass [Agrostis stolonifera var. palustris (Huds.) Farw.] clonal lines were investigated to understand whether these natural compounds could improve the physiological adjustments of creeping bentgrass under low temperature exposure. A marine peptide hydrolysate, and chitosan oligosaccharide (COS) derived from marine chitin were applied to creeping bentgrass foliage and then subjected to cold temperature (4°C, day/night temperature) for 3 wk. Significant stimulation of total phenolic content (8%‐CB 27 to 75%‐CB 15) and antioxidant enzyme response (16%‐CB 27 to 44% CB 13) was observed in creeping bentgrass clonal lines following application of marine peptide + COS. Superoxide dismutase (SOD) (13–50%), and guaiacol peroxidase (GPX) activity (58–99%) increased significantly after treatments in all creeping bentgrass clonal lines, and stimulation of antioxidant enzyme activity was more profound in low phenolic creeping bentgrass clonal lines. Higher glucose‐6‐phosphate dehydrogenase (G6PDH) and higher proline dehydrogenase (PDH) activity was also observed in these lines following application of marine peptide + COS. Stimulation of pentose phosphate pathway (PPP) and a probable proline oxidation in creeping bentgrass clonal lines after foliar application of marine peptide ± COS suggest a role for the enzymes in the improvement of these lines.