Metabolite variations in sulla shoots induced by drought stress

BACKGROUND: Climate change results in an increased occurrence of drought periods, which affect the performance of Mediterranean legumes such as sulla. To evaluate the effects of drought stress on the antioxidant capacity and the accumulation of phytochemicals in sulla shoots, rainfed and drought-stressed plants (RAI) and watered plants with timely vegetative regeneration (STI) were cultivated in parallel in a field experiment and sampled at four different times. RESULTS: Drought stress strongly and positively affected the antioxidant capacity and the accumulation of polyphenols in sulla shoots, with key differences at wintertime. These findings were supported through untargeted and targeted metabolomics of RAI and STI samples, which detailed the accumulation of about 300 secondary metabolites in RAI, mostly polyphenols and saponins. CONCLUSION: This study provided new insights into the changes in secondary metabolites in sulla due to drought stress, which can be used to produce forages or raw plant extracts with enhanced biological effects.