Impacts of elevated ozone on growth and photosynthesis of Metasequoia glyptostroboides Hu et Cheng.
Impacts of elevated ozone on growth and photosynthesis of Metasequoia glyptostroboides Hu et Cheng.
复制标题
DOI：
10.1016/j.plantsci.2014.06.005
复制
发表时间：
2014-09
期刊：
影响因子：
--
通讯作者：
Weiwei Zhang;Zhaozhong Feng;Xiaoke Wang;J. Niu
中科院分区：
文献类型：
--
作者：
Weiwei Zhang;Zhaozhong Feng;Xiaoke Wang;J. Niu
将1年生水杉幼苗置于无过滤环境空气（NF）和高浓度臭氧（E-O3，NF + 60 ppb）中，在开顶式培养箱中培养2年。E-O3处理加速了叶片的衰老，表现为光合色素含量随O3暴露时间的延长而显著降低。E-O_3显著影响气体交换和羧化，导致光饱和光合作用（Asat）、Rubisco最大活性（Vc，max）和最大电子传递速率（Jmax）降低。叶绿素a/B、Vc、max/Jmax和气孔限制（l）不受影响。气孔导度（gs）显着下降，在第一年的E-O3，但保持不变，在第二年。由此可以推断，E-O_3降低Asat的主要原因是非气孔因子的变化。暴露2年后，E-O3显著降低了冠层光合作用和单位面积叶重，显著增加了分枝数，但对生长和生物量的影响不显著。因此，可以认为，该物种的碳积累。长期暴露于高浓度O3后，对水螅类的生长有不利影响。
One-year-oldMetasequoia glyptostroboidesseedlings were exposed to non-filtered ambient air (NF) and elevated ozone (E-O3, NF + 60 ppb) in open-top chambers for two years. E-O3accelerated leaf senescence, as indicated by significant decreases in photosynthetic pigment contents with the elongation of O3exposure. E-O3significantly affected gas exchange and carboxylation, inducing reductions in light-saturated photosynthesis (Asat), the maximum activity of Rubisco (Vc,max) and the maximum electron transport rate (Jmax). Chl a/b,Vc,max/Jmaxand stomatal limitation (l) were not affected. Stomatal conductance (gs) was significantly decreased by E-O3in the first year, but remained unchanged in the second year. It can be inferred that the decrease inAsatby E-O3was mainly attributed to the changes in non-stomatal factors. After two years’ exposure, E-O3caused significant decreases in canopy photosynthesis and leaf mass per area, and a significant increase in the number of branches, but induced slight, not significant decreases in growth and biomass. Therefore, it can be concluded that the carbon accumulation of the speciesM. glyptostroboidescould be negatively affected after long-term exposure to high O3concentration.