Nano silicon causes a shift in rhizospheric soil microbial community structure and improves nutrient uptake and assimilation in tomato plants under low temperature

Low temperatures pose a significant threat to agricultural production, particularly during early spring, late autumn, and winter in northern China, adversely affecting the yield and quality of cold-sensitive crops, such as tomato (Solanum lycopersicum L.). Nano-silicon (SiNPs) represent a prominent application of nanotechnology in agriculture, owing to their unique structure and physicochemical properties, which have demonstrated remarkable efficacy in enhancing plant stress resistance. In this study, we utilized 'Zhongza 9′ tomato cultivar as the test material to investigate the effects of SiNPs, applied through foliar spraying at a concentration of 100 mg·L−1, on nutrient uptake and the microbiome of tomato roots under low-temperature stress. The experiments were conducted using substrate culture at room temperature (25/16℃) and low temperature (15/6℃). The results indicated that the application of SiNPs could enhance the cold tolerance of tomato plants by improving root configuration, photosynthetic capacity, antioxidant capacity, carbon and nitrogen metabolism, as well as nutrient absorption and utilization. Furthermore, SiNPs were found to influence the structure of the rhizosphere microbial community, thereby promoting soil nutrient release. This study elucidates the intricate dynamics between roots, soil, and microbes in mitigating low-temperature stress in plants. Moreover, it provides a crucial theoretical framework for advancing the utilization of SiNPs in agricultural contexts, offering valuable insights for enhancing agricultural productivity in challenging environmental conditions. •NPs enhanced tomato growth and root morphology under low-temperature stress.•NPs improved photosynthesis, chlorophyll content and light energy capture.•NPs elevated key enzyme activities, enhancing carbon and nitrogen metabolism.•NPs positively influenced the rhizosphere microbial community structure.•NPs promoted beneficial microbial diversity and nutrient mineralization.