Figure 9.
PLS-DA analysis of whole metabolomic profiling of lettuce through GC-MS and UPLC VION IMS QTOF-MS/MS analysis by combining means of all different applied NH4+/NO3− ratios (100:0, 75:25, 50:50, 25:75 and 0:100%) and control (no additional N applied) in soil, substrate and hydroponic cultivation systems. Note- (A) PLS-DA analysis using GC-MS in which green color represents hydroponically grown lettuce, red color represents soil-grown lettuce and yellow color represents substrate-grown lettuce; (B) PLS-DA analysis using UPLC VION IMS QTOF-MS/MS in which blue color represents hydroponically grown lettuce, red color represents soil-grown lettuce and yellow color represents substrate-grown lettuce.