In our studies, the accumulation of proline under the influence of treatment with ChCA and ChCA + B. subtilis (Figure 2a) during infection with PVY under normal conditions and with moisture deficiency correlated with an increase in the transcriptional activity of the pyrroline-5-carboxylate synthase (P5CS) gene (Figure 2b), which was shown earlier [36]. This evidence concerns the gene ALDH18A1 and infection.