Tissue D T, Griffin K L, Thomas R B, Strain B R
Department of Botany, Duke University, 27708-0340, Durham, NC, USA.
Oecologia. 1995 Jan;101(1):21-28. doi: 10.1007/BF00328895.
Abutilon theophrasti (C) and Amaranthus retroflexus (C), were grown from seed at four partial pressures of CO: 15 Pa (below Pleistocene minimum), 27 Pa (pre-industrial), 35 Pa (current), and 70 Pa (future) in the Duke Phytotron under high light, high nutrient, and wellwatered conditions to evaluate their photosynthetic response to historic and future levels of CO. Net photosynthesis at growth CO partial pressures increased with increasing CO for C plants, but not C plants. Net photosynthesis of Abutilon at 15 Pa CO was 70% less than that of plants grown at 35 Pa CO, due to greater stomatal and biochemical limitations at 15 Pa CO. Relative stomatal limitation (RSL) of Abutilon at 15 Pa CO was nearly 3 times greater than at 35 Pa CO. A photosynthesis model was used to estimate ribulose-1,5-bisphosphate carboxylase (rubisco) activity (Vc), electron transport mediated RuBP regeneration capacity (J ), and phosphate regeneration capacity (PiRC) in Abutilon from net photosynthesis versus intercellular CO (A-C ) curves. All three component processes decreased by approximately 25% in Abutilon grown at 15 Pa compared with 35 Pa CO. Abutilon grown at 15 Pa CO had significant reductions in total rubisco activity (25%), rubisco content (30%), activation state (29%), chlorophyll content (39%), N content (32%), and starch content (68%) compared with plants grown at 35 Pa CO. Greater allocation to rubisco relative to light reaction components and concomitant decreases in J and PiRC suggest co-regulation of biochemical processes occurred in Abutilon grown at 15 Pa CO. There were no significant differences in photosynthesis or leaf properties in Abutilon grown at 27 Pa CO compared with 35 Pa CO, suggesting that the rise in CO since the beginning of the industrial age has had little effect on the photosynthetic performance of Abutilon. For Amaranthus, limitations of photosynthesis were balanced between stomatal and biochemical factors such that net photosynthesis was similar in all CO treatments. Differences in photosynthetic response to growth over a wide range of CO partial pressures suggest changes in the relative performance of C and C annuals as atmospheric CO has fluctuated over geologic time.
在杜克植物生长室中，将苘麻（C）和反枝苋（C）从种子开始培养，生长在四种CO分压条件下：15 Pa（低于更新世最小值）、27 Pa（工业化前）、35 Pa（当前）和70 Pa（未来），处于高光、高养分和水分充足的条件下，以评估它们对历史和未来CO水平的光合响应。对于C植物，生长CO分压下的净光合作用随CO增加而增加，但C植物并非如此。在15 Pa CO条件下苘麻的净光合作用比在35 Pa CO条件下生长的植物低70%，这是由于在15 Pa CO条件下气孔和生化限制更大。在15 Pa CO条件下苘麻的相对气孔限制（RSL）几乎是35 Pa CO条件下的3倍。利用一个光合作用模型，根据净光合作用与细胞间CO（A-C）曲线来估算苘麻中核酮糖-1,5-二磷酸羧化酶（rubisco）活性（Vc）、电子传递介导的RuBP再生能力（J）和磷酸再生能力（PiRC）。与35 Pa CO条件下生长的苘麻相比，在15 Pa条件下生长的苘麻，这三个组成过程均下降了约25%。与35 Pa CO条件下生长的植物相比，在15 Pa CO条件下生长的苘麻，其总rubisco活性（25%）、rubisco含量（30%）、活化状态（29%）、叶绿素含量（39%）、N含量（32%）和淀粉含量（68%）均显著降低。相对于光反应成分，对rubisco的分配增加，同时J和PiRC降低，这表明在15 Pa CO条件下生长的苘麻中生化过程发生了共同调节。与35 Pa CO条件下生长的苘麻相比，在27 Pa CO条件下生长的苘麻在光合作用或叶片特性方面没有显著差异，这表明自工业时代开始以来CO的升高对苘麻的光合性能影响很小。对于反枝苋，光合作用的限制在气孔和生化因素之间达到平衡，因此在所有CO处理中净光合作用相似。在广泛的CO分压范围内，对生长的光合响应差异表明，随着地质时期大气CO的波动，C和C一年生植物的相对性能发生了变化。
