Multivariate **data** analysis, in particular PCA technique, was employed to characterize biochemical changes in the cassava leaf tissue induced by B. subtilis strain CaSUT007. Score plots were used to visualize any clustering of similar spectra within the **dataset**s, and loading plots were employed to identify spectral variables that best explained clustering patterns. The results were interpreted by taking second derivative spectra showing the negative peak. The second derivative can help Kenneth and Lawrence (2005) and Dokken and Davis (2007) and McCann et al. (1992McCann et al. ( ) 1650 Amide I band (C=O Stretch (80%), C-N stretch (10%), N-H bending (10%) Yu (2004Yu ( , 2005Yu ( , 2008 and Pelton and McLean (2000), Nelson (1991) and Wetzel andLevine (2000) 1550 Amide II (N-H bend (60%), C-N stretch (40%) Yu (2004Yu ( , 2005 and Pelton and McLean (2000); Nelson (1991); Wetzel andLeVine (2000) 1510 C=C aromatic ring from lignin Colthup et al. (1964), Campbell and Sederoff (1996) and Wetzel andLeVine (2000) 1450 Asymmetric CH 2 and CH 3 bending from lipids, protein, lignin Kenneth and Lawrence (2005) and Colthup et al. (1964Colthup et al. ( ) 1370 Symmetric CH 2 and CH 3 bending from lipids, protein, lignin Kenneth and Lawrence (2005) and Colthup et al. (1964Colthup et al. ( ) 1246 C-O Stretching from hemicelluloses and lignin Dokken and Davis (2007), Faix (1992) and Kenneth and Lawrence (2005)