## 3 Results
### Stress-Related Metabolites and Antioxidants  
Proline contents were significantly increased due to Cd-stress where up to 86.3% increase in proline contents was observed as compared to control (Table 2). Inoculation with Cd-tolerant, IAA-producing rhizobacterial strains was significantly effective in diluting the effect of Cd-stress on proline contents of _Brassica juncea_ (L.) thus resulting in a significant decrease in proline contents over the uninoculated Cd-stressed control plants. Under Cd-stress, the decrease in proline contents due to inoculation with rhizobacterial strains ranged from 10.2% to 12.4% with the maximum decrease by the strain FN13. The strain FN16 gave non-significant decrease in proline contents when compared with uninoculated \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Isolate**} & \multicolumn{2}{c}{**Cadmium Levels (mg kg\({}^{-1}\))**} \\ \cline{2-3}  & **0** & **150** \\ \hline \multicolumn{3}{c}{**SPAD Value**} \\ Uninoculated Control & 53.57 \(\pm\) 2.50 b & 38.94 \(\pm\) 1.56 d \\ FN13 & 60.55 \(\pm\) 1.67 a & 45.84 \(\pm\) 0.60 c \\ FN14 & 58.00 \(\pm\) 0.71 ab & 43.66 \(\pm\) 0.82 cd \\ FN16 & 56.08 \(\pm\) 0.90 ab & 42.98 \(\pm\) 0.74 cd \\ LSD (\(p\leq 0.05\)) & \multicolumn{3}{c}{6.5593} \\ \multicolumn{3}{c}{**Relative water contents (\%)**} \\ Uninoculated Control & 71.69 \(\pm\) 1.24 a & 54.89 \(\pm\) 2.31 b \\ FN13 & 75.85 \(\pm\) 1.94 a & 61.07 \(\pm\) 1.07 b \\ FN14 & 74.50 \(\pm\) 1.51 a & 55.97 \(\pm\) 1.00 b \\ FN16 & 73.80 \(\pm\) 0.80 a & 58.71 \(\pm\) 1.65 b \\ LSD (\(p\leq 0.05\)) & \multicolumn{3}{c}{7.4295} \\ \multicolumn{3}{c}{**Proline contents (mg g\({}^{-1}\) fresh weight)**} \\ Uninoculated Control & 3.08 \(\pm\) 0.05 c & 5.74 \(\pm\) 0.22 a \\ FN13 & 3.02 \(\pm\) 0.06 c & 5.03 \(\pm\) 0.21 b \\ FN14 & 3.04 \(\pm\) 0.04 c & 5.06 \(\pm\) 0.11 b \\ FN16 & 3.05 \(\pm\) 0.06 c & 5.15 \(\pm\) 0.17 ab \\ LSD (\(p\leq 0.05\)) & \multicolumn{3}{c}{0.6668} \\ \hline \hline \end{tabular}  
* Means with same alphabets do not differ statistically from one another (\(p\leq 0.05\)).  
\end{table} 
Table 2: Effects of Cd-tolerant, IAA and exopolysaccharides (EPS)-producing rhizobacterial strains on physiological parameters of _Brassica juncea_ (L.) plants under Cd-stress in pot trial; (\(n=3\)). Cd-stressed control plants. Under unstressed conditions, the inoculation with all strains gave non-significant decrease in proline contents of _Brassica juncea_ (L.) plants. Data regarding SOD activity of _Brassica juncea_ (L.) plants showed that the activity of SOD enzyme was increased due to Cd-stress (Figure 4A). The inoculation with Cd-tolerant, IAA-producing rhizobacterial strains further enhanced the SOD activity in _Brassica juncea_ (L.) plants under Cd-stress. The increase, however, was non-significant when compared with the respective uninoculated control plants. Under Cd-stress, the maximum SOD activity (251.74 units g\({}^{-1}\) fresh weight) was observed in the plants inoculated with strain FN13 followed by FN14 and FN16. The strains also showed non-significant increase in SOD activity of _Brassica juncea_ (L.) plants under unstressed conditions. As observed in the case of SOD activity, the POX activity of _Brassica juncea_ (L.) plants was also significantly increased due to Cd-stress (Figure 4B). The inoculation with Cd-tolerant, IAA-producing rhizobacterial strains further enhanced the POX activity in _Brassica_ plants under Cd-stress. The increase, however, was non-significant when compared with respective uninoculated control plants. Under Cd-stress, the maximum POX activity was observed in the plants inoculated with strain FN13 followed by FN14 and FN16. All strains showed non-significant increase in POX activity of _Brassica juncea_ (L.) plants under unstressed conditions and Cd-stress. The inoculation with rhizobacterial strains further enhanced the CAT activity in _Brassica juncea_ (L.) plants under Cd-stress. The increase, however, was non-significant when compared with respective uninoculated control plants.