Response of Metabolites in Cymbopogon distans Leaves to Water Addition in Karst Areas during Different Seasons

Climate change could influence the plant response to drought stress in karst environments. However, fewer related studies have been reported. This study examined the impact of artificial water addition on the accumulation of metabolites of Cymbopogon distans with a non-targeted metabolomics approach during both the dry and wet seasons. Three water treatment gradients (CK, T1, and T2, indicating 0%, +20%, and +40% relative to the average monthly precipitation, respectively) were chosen. The findings of our study indicate that the levels of primary metabolites were higher in the leaves of C. distans during the dry season compared to the rainy season. In addition, the presence of water did not have a substantial impact on the composition and functionality of metabolites between the wet and drought seasons. The contents of some lipids were greater during the dry season, while others were greater during the wet season. During the dry season, the contents of FA, DG, MGDG, SQDG, TG, and PR decreased with water addition. Our findings demonstrated that artificial water addition might have a greater impact on metabolite accumulation during the dry season in drought-tolerant species in karst areas. Due to the buildup of certain metabolites, they exhibit clear drought resistance. At the same time, water addition during the dry season will also cause a certain stress, affecting the adaptability of plants. These findings have significant ramifications for the management and choice of species in various sea seasons in karst regions.