Figure 3.

Principal component analysis (PCA) to understand parameter and treatment variability in maize plants. (A) The parameters included FW (fresh weight) DW (dry weight), leaf area, Chl a (chlorophyll a), Chl b (chlorophyll b), Carot (carotenoids), soluble sugars, soluble protein, proline, MDA (malondialdehyde), CAT (catalase), APX (ascorbate peroxidase), POD (peroxidase), P (phosphorous) and K (potassium). (B) The treatment triangles in different colors include Control, plants without copper stress and bacterial strains inoculation; Cu 1: plants exposed to 100 µM CuSO₄; Cu 2: plants exposed to 500 µM CuSO₄; P. polymyxa (Pp) inoculated plants without CuSO₄; Cu 1 + Pp: plants exposed to 100 µM CuSO₄ and inoculated with P. polymyxa; Cu 2 + Pp: plants exposed to 500 µM CuSO₄ and inoculated with P. polymyxa; B. circulans (Bc) inoculated plants without CuSO₄; Cu 1 + Bc: plants exposed to 100 µM CuSO₄ and inoculated with B. circulans and Cu 2 + Bc: plants exposed to 500 µM CuSO₄ and inoculated with B. circulans.