Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK
J Exp Bot. 2017 Jan;68(2):107-116. doi: 10.1093/jxb/erw438. Epub 2016 Dec 10.
C photosynthesis is a carbon-concentrating mechanism that increases delivery of carbon dioxide to RuBisCO and as a consequence reduces photorespiration. The C pathway is therefore beneficial in environments that promote high photorespiration. This pathway has evolved many times, and involves restricting gene expression to either mesophyll or bundle sheath cells. Here we review the regulatory mechanisms that control cell-preferential expression of genes in the C cycle. From this analysis, it is clear that the C pathway has a complex regulatory framework, with control operating at epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels. Some genes of the C pathway are regulated at multiple levels, and we propose that this ensures robust expression in each cell type. Accumulating evidence suggests that multiple genes of the C pathway may share the same regulatory mechanism. The control systems for C photosynthesis gene expression appear to operate in C plants, and so it appears that pre-existing mechanisms form the basis of C photosynthesis gene expression.
C 光合作用是一种碳浓缩机制，可增加二氧化碳向 RuBisCO 的传递，从而减少光呼吸。因此，在促进高光呼吸的环境中，C 途径是有益的。该途径已经进化了很多次，涉及到将基因表达限制在叶肉细胞或束鞘细胞中。在这里，我们回顾了控制 C 循环中基因细胞偏好表达的调节机制。从这个分析中，可以清楚地看出，C 途径具有复杂的调节框架，在表观遗传、转录、转录后、翻译和翻译后水平上进行控制。C 途径的一些基因受到多个水平的调节，我们提出这可以确保在每种细胞类型中都有稳健的表达。越来越多的证据表明，C 途径的多个基因可能具有相同的调节机制。C 光合作用基因表达的控制系统似乎在 C 植物中起作用，因此，似乎是预先存在的机制构成了 C 光合作用基因表达的基础。
