Sulfur is an essential nutrient required for plant growth and metabolism, and plays an important role in relieving stress. Nutrient deficiency is one of the main factors that negatively affect crop growth, quality, and yield. This study aimed to evaluate the effect of sulfur nutrients on the growth and metabolites of lettuce after treatment with two different sulfur concentrations (16 μM and 2 mM) in spray hydroponics. The fresh weight, chlorophyll, and carotenoid content of lettuce leaves were analyzed. Root morphology was examined using the WinRHIZO program. Metabolites were comparatively evaluated with the help of LC-MS and GC-MS. The fresh weight, chlorophyll, and carotenoid contents of lettuce were higher in the high concentration sulfur treatment group than in the low concentration sulfur treatment group. In the characteristics analysis of the lettuce roots, treatment with a high concentration of sulfur had a more positive effect on the lettuce root development than treatment with a low concentration of sulfur. Moreover, mass-based metabolomics analysis showed that the lettuce metabolites content was significantly different according to low- and high-concentration sulfur treatments. Therefore, this study highlights the importance of sulfur nutrient content in lettuce growth and metabolites.

Salt stress is one of the environmental stresses that significantly reduces crop productivity and quality worldwide. Methods to overcome salt stress include developing salt-resistant crops by inserting various resistance genes or to diagnosing and responding to the effects of salt stress at an early stage. In this study, we investigate the effects of salinity stress on growth, photosynthetic efficiency, and metabolic changes in Brussels sprouts (Brassica oleracea var. gemmifera). Fresh weight and leaf area decreased significantly with increasing NaCl concentration, indicating that salinity stress has a detrimental effect on plant growth. However, chlorophyll fluorescence parameters did not show significant changes, suggesting that photosynthetic efficiency was not significantly affected over 10 days. Fourier transform infrared (FTIR) spectroscopy revealed notable metabolic adjustments, especially in lipids, plastids, proteins, and carbohydrates, indicating biosynthesis of protective compounds such as anthocyanins and proline in response to salinity stress. Pearson correlation analysis confirmed a strong relationship between NaCl concentration and the observed physiological and metabolic changes. The findings highlight the potential of FTIR spectroscopy as a non-destructive tool for early detection of salinity stress and timely intervention to improve crop resilience and yield. This study highlights the widespread application of FTIR spectroscopy in agricultural research to manage abiotic stresses in crops.

This study aims to evaluate the feasibility and benefits of integrating photovoltaic (APV) systems with rice cultivation, focusing on growth characteristics, chlorophyll content and fluorescence, yield components, and electricity production. An APV system was installed over a rice paddy area in Namhae-gun, Gyeongsangnam-do, with 607 modules providing a total capacity of approximately 97.12 kW. The Baegokchal variety of rice was cultivated following standard practices, and growth characteristics, chlorophyll content, and fluorescence were measured throughout the growing period. Yield components were analyzed, and electricity production was monitored to assess the performance of the APV system. The rice growing period in 2021 experienced lower than average temperatures and higher rainfall. Despite these conditions, rice in the APV systems showed increased chlorophyll content and fluorescence, indicating an adaptive response to reduced sunlight. Rice plants in APV systems exhibited greater plant height but fewer tillers compared to the control group. Leaves were significantly longer and wider, enhancing photosynthetic efficiency under shading. The yield of rice in APV systems was reduced by approximately 9% compared to the control, less severe than that reported in other studies. The APV system demonstrated stable electricity production, with consistent output throughout the year, despite variations in solar radiation. Integrating photovoltaic systems with rice cultivation is feasible and beneficial, providing a reliable source of renewable energy and enhancing farm income despite a slight reduction in rice yield. This study highlights the potential of APV systems to contribute to sustainable agriculture and renewable energy expansion, suggesting the need for further research on various crops and conditions to optimize system performance.