## 2 Results  
### Plant-Growth-Promoting Effects of mVOCs under Salinity Conditions  
When plants were exposed to mVOCs under control conditions, only the shoot length was increased (\(p<0.05\)) by both strains (Table 1). In contrast, when plants were grown under 75 and 100 mM salt stress conditions, the SJ46 mVOCs increased the number of leaves significantly, by approximately 60-70% (\(p<0.05\)), while SJ04 only showed an increase at 100 mM. The number of ramifications revealed the same tendency for both stress conditions for SJ46 mVOCs, but with SJ04 only showing an increase at 100 mM (\(p<0.05\)). The number of nodes was increased by mVOCs of both strains under all conditions evaluated (\(p<0.05\)). However, only SJ46 mVOCs increased the shoot length significantly under 100 mM conditions (\(p<0.05\)). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Leaf n\({}^{\text{a}}\)** & **Node n\({}^{\text{a}}\)** & **Ramification n\({}^{\text{a}}\)** & **Shoot Length (cm)** & **Root Length (cm)** \\ \hline
0 mM & & & & & \\ Non-exposed & 25.36 \(\pm\) 1.36 deg & 13.23 \(\pm\) 0.60 deg & 1.86 \(\pm\) 0.21 deg & 7.81 \(\pm\) 0.85 deg & 10.92 \(\pm\) 0.51 deg \\ SJ46 & 27.33 \(\pm\) 1.31 deg & 14.00 \(\pm\) 0.96 deg & 2.17 \(\pm\) 0.27 deg & 10.73 \(\pm\) 0.92 deg & 10.98 \(\pm\) 1.11 deg \\ SJ04 & 29.70 \(\pm\) 1.11 deg & 14.10 \(\pm\) 0.35 deg & 2.00 \(\pm\) 0.00 deg & 9.67 \(\pm\) 0.86 deg & 12.00 \(\pm\) 1.64 deg \\ \hline
75 mM & & & & & \\ Non-exposed & 18.00 \(\pm\) 1.95 deg & 9.33 \(\pm\) 0.96 deg & 1.78 \(\pm\) 0.36 deg & 4.13 \(\pm\) 0.45 deg & 5.07 \(\pm\) 0.83 deg \\ SJ46 & 32.00 \(\pm\) 2.74 deg & 14.50 \(\pm\) 2.37 deg & 3.10 \(\pm\) 0.50 deg & 3.60 \(\pm\) 0.54 deg & 5.19 \(\pm\) 1.36 deg \\ SJ04 & 20.00 \(\pm\) 1.92 deg & 10.29 \(\pm\) 1.08 deg & 1.75 \(\pm\) 0.25 deg & 4.89 \(\pm\) 0.59 deg & 4.90 \(\pm\) 0.52 deg \\ \hline
100 mM & & & & & \\ Non-exposed & 13.33 \(\pm\) 2.01 deg & 7.31 \(\pm\) 1.15 deg & 1.45 \(\pm\) 0.21 deg & 1.42 \(\pm\) 0.16 deg & 2.59 \(\pm\) 0.56 deg \\ SJ46 & 22.83 \(\pm\) 2.07 deg & 13.40 \(\pm\) 0.91 deg & 2.40 \(\pm\) 0.45 deg & 3.56 \(\pm\) 0.44 deg & 4.80 \(\pm\) 0.49 deg \\ SJ04 & 23.60 \(\pm\) 3.30 deg & 12.50 \(\pm\) 1.86 deg & 3.00 \(\pm\) 0.33 deg & 2.14 \(\pm\) 0.27 deg & 4.65 \(\pm\) 1.05 deg \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The effect on _M. piperita_ of mVOCs emitted by native _P. putida_ SJ04 and SJ46 plant-growth-promoting bacteria for different growth parameters under salt stress conditions (0 mM, 75 mM and 100 mM). Means followed by the same letter within a column are not significantly different according to [PERSON]’s LSD test (\(p<0.05\)). Regarding the fresh weight of the shoot, a negative effect of salt (\(p<0.05\)) was clearly observed, with plants grown under 75 and 100 mM registering just a half and a third, respectively, of the shoot fresh weight of control plants (Figure 1). When plants were exposed to mVOCs in the absence of salt stress (0 mM), none of the strains evaluated (SJ04 and SJ46) revealed growth-promoting effects (\(p>0.05\)). The opposite was observed at 75 mM NaCl, as compared to control plants (not exposed to mVOCs); the shoot fresh weight increased by approximately 70% when exposed to SJ46 VOCs. The same tendency was observed for severe stress (100 mM), with an increase of approximately two times being recorded in plants in contact with SJ04 or SJ46 volatiles, compared to the control without VOC exposure (\(p<0.05\)). The weight values of plants grown under 100 mM and treated with mVOC emissions were similar to untreated plants under 75 mM NaCl. Under non-salt stress conditions, the mVOCs did not significantly affect the root dry weight (Figure 2) or the length of the main root (Table 1) (\(p>0.05\)). Under 75 mM, the root dry weight from plants treated with SJ04 or SJ46 mVOCs showed a 35-45% increase, respectively, in comparison with plants stressed but not exposed to mVOCs (\(p<0.05\)).