THE RELATIONSHIP BETWEEN CARBON-DIOXIDE-LIMITED PHOTOSYNTHETIC RATE AND RIBULOSE-1,5-BISPHOSPHATE-CARBOXYLASE CONTENT IN 2 NUCLEAR-CYTOPLASM SUBSTITUTION LINES OF WHEAT, AND THE COORDINATION OF "RIBULOSE-BISPHOSPHATE-CARBOXYLATION AND ELECTRON-TRANSPORT CAPACITIES
THE RELATIONSHIP BETWEEN CARBON-DIOXIDE-LIMITED PHOTOSYNTHETIC RATE AND RIBULOSE-1,5-BISPHOSPHATE-CARBOXYLASE CONTENT IN 2 NUCLEAR-CYTOPLASM SUBSTITUTION LINES OF WHEAT, AND THE COORDINATION OF "RIBULOSE-BISPHOSPHATE-CARBOXYLATION AND ELECTRON-TRANSPORT CAPACITIES
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DOI：
10.1007/bf00391338
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发表时间：
1986-01-01
期刊：
影响因子：
4.3
通讯作者：
EVANS, JR
中科院分区：
文献类型：
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作者：
EVANS, JR
比较了两个普通小麦品种的光合作用和两个核基因组相同但细胞质来源于小麦的品系的光合作用。植物4.1.1.39从T. boeoticum细胞质中的DNA含量仅为正常T.小麦相比之下，RuBPCase活性计算的CO2同化率在低分压的CO2，p（CO2），是相同的所有线路为一个给定的RuBPCase含量。这表明两种类型的RuBPCase在体内具有相同的周转数27.5mol CO2·cm-1。(mol酶）-1. s-1（23 °）。在正常p（CO2），pa = 340和高辐照下测量的CO2同化率可以从RuBPCase蛋白质的量定量预测。mu.bar RuBP再生的最大速率也可以预测正常环境条件下的CO2同化速率。因此，RuBP羧化和RuBP再生的最大能力似乎在正常环境条件下平衡良好。随着叶龄的增加，光合能力下降，RuBP羧化和RuBP再生的能力平行下降。
Photosynthesis in two cultivars of Triticum aestivum was compared with photosynthesis in two lines having the same nuclear genomes but with cytoplasms derived from T. boeoticum. The in-vitro specific activity of ribulose-1,5-bisphosphate carboxylase (RuBPCase; EC 4.1.1.39) isolated from lines with T. boeoticum cytoplasm was only 71% of that of normal T. aestivum. By contrast, the RuBPCase activities calculated from the CO2-assimilation rate at low partial pressures of CO2, p(CO2), were the same for all lines for a given RuBPCase content. This indicates that both types of RuBPCase have the same turnover numbers in-vivo of 27.5 mol CO2 .cntdot. (mol enzyme)-1 .cntdot. s-1 (23.degree.). The rate of CO2 assimilation measured at normal p(CO2), pa = 340 .mu.bar, and high irradiance could be quantitatively predicted from the amount of RuBPCase protein. The maximum rate of RuBP regeneration could also predict the rate of CO2 assimilation at normal ambient conditions. Therefore, the maximum capacities for RuBP carboxylation and RuBP regeneration appear to be well-balanced for normal ambient conditions. As photosynthetic capacity declined with increasing leaf age, the capacities for RuBP carboxylation and RuBP regeneration declined in parallel.