The primed (T1D, T2D, T3D) plants showed higher activity of P5CS, and non-significant difference of PDH activity compared with the non-primed (T0D) plants, indicating that higher proline content induced in the primed plants was mainly ascribed to the elevated P5CS activity rather than modification of PDH activity. The gene discussed is ALDH18A1; the disease is type 2 diabetes mellitus.