Fig. 3.
Relationships between bundle sheath leakiness and ln(Ci) under low (N1, circles; A) or high N supply (N2, triangles; B) combined with low (V1, open symbols, dashed lines) or high VPD (V2, filled symbols, solid lines). Operating conditions of gas exchange measurements were the same as conditions in growth chambers (leaf temperature 25 °C, PPFD 800 μmol m−2 s−1, VPD 0.8 kPa for V1 and 1.6 kPa for V2). Data are shown as the mean±SE (n=5–6). The data of each N level were fitted by linear regression including a dummy variable indicating VPD treatments (V) after the confirmation of parallelism of the two regressions of VPD levels: with V=0 for low VPD and V=1 for high VPD (for equations see Table 2).