Fig. 3 in Metabolic markers for the yield of lipophilic indole alkaloids in dried woad leaves (Isatis tinctoria L.)

Fig. 3. Correlation circles of PLS regression, illustrating the correlations of the variables with the first three PLS components. Strongly positively correlated variables are projected in the same direction from the origin. Strongly negatively correlated variables are projected at diametrically opposite places on the correlation circle, whereas variables that are not correlated are situated 90̊ from each other in the circle. The longer the distance to the origin, the stronger the relationship between the variables. Only variables closely located to the circumference of radius 1 can be directly interpreted. For variables closely located to the origin, some information can be carried on other dimensions. Abbreviations: ac.ind, acetylindican; diox.glc, dioxindole glucoside; glcbr, glucobrassicin; glctro, glucotropaeolin; HO.ICOOglc, 6-hydroxyindole-3-carboxylic acid glucose ester; IsA, isatan A; IsB, isatan B; mal.ind, malonylindican. All abbreviations are given in Supplemental Table 1.