Small decreases in SBPase cause a linear decline in the apparent RuBP regeneration rate, but do not affect Rubisco carboxylation capacity
Small decreases in SBPase cause a linear decline in the apparent RuBP regeneration rate, but do not affect Rubisco carboxylation capacity
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DOI：
10.1093/jexbot/52.362.1779
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发表时间：
2001-09-01
影响因子：
6.9
通讯作者：
Raines, CA
中科院分区：
文献类型：
--
作者：
Harrison, EP;Olcer, H;Raines, CA
以6个独立转化系为材料，研究了反义烟草叶片光合CO2净吸收(A)对叶片胞间CO2浓度（ci）的响应。结果表明，反义烟草植株的sedoheptulose- 1,7 -双磷酸酶（SBPase）活性不同。根据稳态测量的A - ci响应曲线计算体内最大核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）羧化（V-c,V-max）和RuBP再生（J(max)）速率。当SBPase活性降低9% ~ 60%时，RuBP的最大再生能力呈线性下降（r(2) = 0.79），且无显著性变化。这些植物体内Rubisco活性（V-c,V-max）发生了变化。在SBPase反义植株中，V-c、V-max与RuBP再生能力的降低没有相关性（r(2) = 0.14）。这些数据表明，SBPase活性的小幅下降通过降低RuBP再生能力来限制光合碳同化。
The response of net photosynthetic CO2 uptake (A) to increasing leaf intercellular CO2 concentration (ci) was determined in antisense Nicotiana tabacum plants, derived from six independent transformation lines, displaying a range of sedoheptulose-1, 7-bisphosphatase (SBPase) activities. The maximum in vivo ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V-c,V-max) and RuBP regeneration (J(max)) rates were calculated from the steady-state measurements of the A to ci response curves. In plants with reductions in SBPase activity of between 9% and 60%, maximum RuBP regeneration capacity declined linearly (r(2) = 0.79) and no significant.,m J change in apparent in vivo Rubisco activity (V-c,V-max) was observed in these plants. No correlation between V-c,V-max and a decrease in capacity for RuBP regeneration was observed (r(2) = 0.14) in the SBPase antisense plants. These data demonstrate that small decreases in SBPase activity limit photosynthetic carbon assimilation by reducing the capacity for RuBP regeneration.