Fig. 9
PCA (Principal component analysis) of physiological changes of 4 species. a, b PC 1–PC 2 and PC 1–PC 3 variables loading plots; c, d PC 1–PC 2 and PC 1–PC 3 samples score plots. PC 1 mainly including dry weight, photosynthetic rate (A), relative water content (RWC), CAT, SOD, Car, proline; PC 2 mainly include APX, MDA, root/shoot, instantaneous water use efficiency (WUEi), stomatal conductance (Gs) and transpiration rate (E); PC 3 mainly include ASA, POD and soluble sugar. R 1: the small root system, R 2: the large root system, L 1: isolateral leaf or transitional form, L 2: bifacial leaf. 1–3: A. sacrorum in control, 4–6: A. sacrorum in drought stress, 7–9: A. scoparia in control, 10–12: A. scoparia in drought stress, 13–15: A. giraldii in control, 16–18: A. giraldii in drought stress, 19–21: A. annua in control, 22–24: A. annua in drought stress