Nitrogen Application Alleviates the Adverse Effects of Defoliation Stress on Lolium perenne L. by Enhancing the Antioxidant System and Promoting Photosynthesis

Perennial grasses undergo compensatory growth after defoliation. Nitrate is the main nitrogen source for of perennial ryegrass and plays a significant role in plant resistance to stress. The aim study was understand physiological mechanism response defoliation stress under different nitrate supplies explore possible ways alleviate We performed pot experiments where 12-week-old plants grown low (0.05 mM KNO3) or moderate (5 conditions were defoliated subsequently supplied with concentrations following treatments. During regrowth stage, rate, biomass, photosynthetic parameters, antioxidant system supply investigated. results showed that increased content pigments improved its efficiency. In addition, adding activity enzymes accumulation osmotic regulating substances, thereby enhancing resistance, effectively reducing damage caused by stress, promoting regrowth, especially environment before Therefore, this addition exogenous could counteract some adverse effects on development ryegrass.