Rubisco specificity factor tends to be larger in plant species from drier habitats and in species with persistent leaves
Rubisco specificity factor tends to be larger in plant species from drier habitats and in species with persistent leaves
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DOI：
10.1111/j.1365-3040.2005.01300.x
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发表时间：
2005-05-01
影响因子：
7.3
通讯作者：
Parry, MAJ
中科院分区：
文献类型：
--
作者：
Galmés, J;Flexas, J;Parry, MAJ
Rubisco的特异性因子是酶催化1，5-二磷酸核酮糖羧化和氧化从而控制光合作用碳同化和光呼吸相对速率的相对能力的量度。从24种C-3植物中发现的纯化Rubisco的特异性因子在25℃下被测量，这些植物分布在不同的生境中，环境生长受到巴利阿里群岛水可获得性和温度的广泛限制。结果表明，特异性因子更多地依赖于环境压力而不是系统发育因素。无论系统发育关系如何，在生长在干燥环境中的物种以及半落叶或常绿物种中发现了更高的特异性因子。温度对纯化的14种酶的专一性因子的影响与以下概念一致：与RuBP的2，3-烯二醇酯向相应过渡态中间体的羧化相比，更高的专一性因子与氧化活化能增加有关。根据选择压力对结果进行了讨论，这些结果导致了特异性因子的差异，以及观察到的识别改变Rubisco多肽亚基的有用遗传操作的价值。
The specificity factor of Rubisco is a measure of the relative capacities of the enzyme to catalyse carboxylation and oxygenation of ribulose 1,5-bisphosphate and hence to control the relative rates of photosynthetic carbon assimilation and photorespiration. Specificity factors of purified Rubisco from 24 species of C-3 plants found in diverse habitats with a wide range of environmental growth limitations by both water availability and temperature in the Balearic Islands were measured at 25 degrees C. The results suggest that specificity factors are more dependent on environmental pressure than on phylogenetic factors. Irrespective of phylogenetic relationships, higher specificity factors were found in species characteristically growing in dryer environments and in species that are hemideciduous or evergreen. Effects of temperature on specificity factor of the purified enzyme from 14 species were consistent with the concept that higher specificity factors were associated with an increase in the activation energy for oxygenation compared to carboxylation of the 2,3-enediolate of RuBP to the respective transition state intermediates. The results are discussed in terms of selection pressures leading to the differences in specificity factors and the value of the observations for identifying useful genetic manipulation to change Rubisco polypeptide subunits.