Will an algal CO2-concentrating mechanism work in higher plants?
Will an algal CO2-concentrating mechanism work in higher plants?
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DOI：
10.1016/j.pbi.2016.04.009
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发表时间：
2016-06
影响因子：
9.5
通讯作者：
Moritz T. Meyer;A. McCormick;H. Griffiths
中科院分区：
文献类型：
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作者：
Moritz T. Meyer;A. McCormick;H. Griffiths
在高等植物中，要提高RuBisCO的运行效率，就需要在所有高等植物的质体中都有一个藻类CCM。在衣原体中，已经确定了一种将RuBisCO包装到类蛋白核系统中的蛋白质。编码藻类无机碳转运蛋白的基因可以在高等植物中正确地靶向蛋白质。叶绿体类囊体组织，能量学和离子平衡与CCM将需要表征。许多藻类使用生物物理碳浓缩机制进行主动积累，无机碳保留在叶绿体内，而二氧化碳则被RuBisCO固定在一个微区室（蛋白核）内。将这样的机制工程化到高等植物叶绿体中是提高RuBisCO操作效率和光合速率的可能途径。最近在表征关键的藻类转运蛋白和确定负责RuBisCO聚集成蛋白核的因素方面取得了重大进展。一些转运蛋白现已成功地整合到高等植物叶绿体中。与建模预测一致，在该机制提供潜在益处之前，需要调节高等植物质体碳酸酐酶和某种形式的RuBisCO聚集。关键的研究重点包括更好地了解藻类碳浓缩机制的调节，推进已知成分的基本表征，评估高等植物叶绿体是否可以容纳蛋白核，并最终在现实的生长条件下测试转基因品系。
HighlightsImproving RuBisCO operating efficiency would require an algal CCM in all higher plant plastids.A protein packaging RuBisCO into a pyrenoid-like system has been defined for Chlamydomonas.Genes coding algal inorganic carbon transporters can target proteins correctly in higher plants.Chloroplast thylakoid organisation, energetics and ion balance with a CCM would need characterisation.Many algae use a biophysical carbon concentrating mechanism for active accumulation and retention of inorganic carbon within chloroplasts, with CO 2 fixation by RuBisCO within a micro-compartment, the pyrenoid. Engineering such mechanisms into higher plant chloroplasts is a possible route to augment RuBisCO operating efficiency and photosynthetic rates. Significant progress has been made recently in characterising key algal transporters and identifying factors responsible for the aggregation of RuBisCO into the pyrenoid. Several transporters have now also been successfully incorporated into higher plant chloroplasts. Consistent with the predictions from modelling, regulation of higher plant plastidic carbonic anhydrases and some form of RuBisCO aggregation will be needed before the mechanism delivers potential benefits. Key research priorities include a better understanding of the regulation of the algal carbon concentrating mechanism, advancing the fundamental characterisation of known components, evaluating whether higher plant chloroplasts can accommodate a pyrenoid, and, ultimately, testing transgenic lines under realistic growth conditions.