Plants like Saussurea amara seedlings produce more proline when exposed to salt stress to protect themselves. The researchers studied how proline levels and enzyme activities changed in response to different salt concentrations. They found that proline levels increased in leaves more than in roots with higher salt levels. The enzyme P5CS increased first, then decreased with more salt. Other enzymes, δ-OAT and ProDH, also changed in response to salt. The study showed that proline production in the seedlings depended on the type of salt stress.