| 摘 要： |
Decline in mesophyll conductance (g(m)) plays a key role in limiting photosynthesis in plants exposed to elevated ozone (O-3). Leaf anatomical traits are known to influence g(m), but the potential effects of O-3-induced changes in leaf anatomy on g(m) have not yet been clarified. Here, two poplar clones were exposed to elevated O-3. The effects of O-3 on the photosynthetic capacity and anatomical characteristics were assessed to investigate the leaf anatomical properties that potentially affect g(m). We also conducted global meta-analysis to explore the general response patterns of g(m) and leaf anatomy to O-3 exposure. We found that the O-3-induced reduction in g(m) was critical in limiting leaf photosynthesis. Changes in liquid-phase conductance rather than gas-phase conductance drive the decline in g(m) under elevated O-3,O- and this effect was associated with thicker cell walls and smaller chloroplast sizes. The effects of O-3 on palisade and spongy mesophyll cell traits and their contributions to g(m) were highly genotype-dependent. Our results suggest that, while anatomical adjustments under elevated O-3 may contribute to defense against O-3 stress, they also cause declines in g(m) and photosynthesis. These results provide the first evidence of anatomical constraints on g(m) under elevated O-3. |
在线留言
联系我们
所长信箱