Metabolomic profiling reveals Hydrogen sulfide-induced alterations in the secondary metabolite production of Trigonella foenum-graecum (Fenugreek).

Hydrogen sulfide (H₂S) plays a crucial role in regulating growth, development, and metabolic processes in various plant systems. The current study emphasises on how H₂S signalling affects the physical and physiological parameters, including the secondary metabolome of Trigonella foenum-graecum (Fenugreek) through a spectrophotometric method and untargeted liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Under controlled lab conditions, 15-day-old Fenugreek plants were treated with H₂S and repeated at regular intervals of 5 days up to 60 days. On the 60^th day, plants were harvested, physiological parameters were measured and leaf samples were frozen in liquid nitrogen and stored at -80° C for further analysis. Targeted metabolite analysis of leaf samples was performed using UV spectrophotometric method. It was observed that 100μM H₂S treatment was optimal for improving plant physical growth parameters, phenolic content, and flavonoid accumulation, whereas 200μM H₂S was more effective in enhancing photosynthetic pigments and alkaloid content. Preliminary analysis by spectrophotometric method revealed notable alterations in secondary metabolites, such as phenolic compounds, flavonoids, and alkaloids. The current findings suggest that H₂S acts as a potent modulator of plant metabolic pathways involved in secondary metabolite biosynthesis. For a better understanding of the shift in secondary metabolite content in control and H₂S-treated leaf samples, untargeted liquid chromatography-high-resolution mass spectrometry (LC-HRMS) will be performed and presented. The findings of this study can offer new insights into how H₂S influences plant metabolism and deepen our understanding of plant-volatile interactions and their role in specialized metabolic pathways.