Lipidomics Analysis of Tea Leaves Cultured in Hydroponics Reveals That High Nitrogen Application Decreases Tea Plant Resistance to Ultraviolet Radiation

Abstract

Lipid composition in tea leaves is significantly affected by ultraviolet (UV) radiation and nitrogen levels. Here, to reveal the response of lipids in tea plants (Camellia sinensis L.) to the interaction between nitrogen and UV radiation, we treated tea plants with three gradients of UV radiation under two nitrogen levels by the hydroponic method. Lipidomics results show that ultraviolet radiation can decrease neutral lipid (TAG) and increase membrane lipids (including PC, PE, and PG) under hydroponic conditions, indicating that tea plants could survive UV radiation by decomposing TAG to avoid damaging cells. In addition, the accumulation of phospholipids and galactolipids may be related to avoiding UV damage and enhancing photosynthesis in tea plants under UV radiation. Furthermore, the response of lipid components to UV radiation in tea plants under low nitrogen conditions is significantly lower than that under high nitrogen conditions, which suggests that excessive nitrogen application may reduce the resistance of tea plants to UV radiation. This study provides a theoretical basis for optimizing cultivation measures based on tea UV resistance.