Fig. 4.
Principal component analysis of endogenous soluble sugars and xenobiotic stress responses of Arabidopsis thaliana accessions. Principal component analysis was performed on the correlation matrix of averages of biochemical parameters [absolute levels of endogenous soluble sugars in shoots at the end of day (EoD) and at the end of night (EoN)] and of physiological traits (absolute levels of Fv/Fm, shoot chlorophylls and shoot carotenoids) measured on the 11 accessions. Soluble sugars were measured in shoots of 2-week-old plantlets prior to atrazine treatment (Tables 2 and 3) and physiological traits were measured after 5 d of transfer onto fresh medium in the absence or presence of 10 µm atrazine. (A) and (B) represent the repartition of accessions in the absence or presence of 10 µM atrazine, respectively. (C) and (D) represent the distribution of variables on the first plane (PC1 and PC2) in the absence or presence of 10 µm atrazine, respectively.