John Innes Institute, Colney Lane, NR4 7UH, Norwich, UK.
Planta. 1987 Jun;171(2):227-34. doi: 10.1007/BF00391098.
Three methods of estimating photorespiratory rate in leaves of the C3-C4 intermediate species Moricandia arvensis and the related C3 species Moricandia moricandioides were compared. The results indicated that the photorespiratory rate in M. arvensis is less than in M. moricandioides, and that this is caused partly by reduced carbon flux through the photorespiratory pathway, and partly by the presence of a mechanism for enhanced photorespiratory CO2 reassimilation in the intermediate species. Measurements of the CO2 compensation point (Γ) in the two species supported this conclusion. A functional C4 pathway is unlikely to be involved in the reduction of photorespiratory rate in M. arvensis since pulse-chase experiments showed that carbon did not move from C4 acids to the reductive pentose-phosphate pathway in attached leaves under steady-state conditions at Γ.
比较了三种估算 C3-C4 中间种鸭茅（Moricandia arvensis）和相关 C3 种鸭茅（Moricandia moricandioides）叶片光呼吸速率的方法。结果表明，鸭茅的光呼吸速率低于鸭茅，这部分是由于通过光呼吸途径的碳通量减少，部分是由于中间种存在增强光呼吸 CO2再同化的机制。对这两个物种的 CO2 补偿点（Γ）的测量支持了这一结论。由于脉冲追踪实验表明，在 Γ 下的稳态条件下，附着叶片中的碳不会从 C4 酸转移到还原戊糖磷酸途径，因此，鸭茅中光呼吸速率的降低不太可能涉及功能性 C4 途径。
