Laboratory of Plant Physiology and Biochemistry, National Institute for Amazonian Research (INPA), Manaus, AM 69011-970, Brazil; University of Amazonas State, Manaus, AM 69050-010, Brazil.
Department of Crop Science and Plant Biology, Estonian University of Life Sciences, Tartu 51006, Estonia; Estonian Academy of Sciences, 10130 Tallinn, Estonia.
Trends Plant Sci. 2018 Dec;23(12):1081-1101. doi: 10.1016/j.tplants.2018.09.012. Epub 2018 Oct 25.
Isoprene and other plastidial isoprenoids are produced primarily from recently assimilated photosynthates via the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. However, when environmental conditions limit photosynthesis, a fraction of carbon for MEP pathway can come from extrachloroplastic sources. The flow of extrachloroplastic carbon depends on the species and on leaf developmental and environmental conditions. The exchange of common phosphorylated intermediates between the MEP pathway and other metabolic pathways can occur via plastidic phosphate translocators. C and C carbon intermediates can contribute to chloroplastic metabolism, including photosynthesis and isoprenoid synthesis. Integration of these metabolic processes provide an example of metabolic flexibility, and results in the synthesis of primary metabolites for plant growth and secondary metabolites for plant defense, allowing effective use of environmental resources under multiple stresses.
异戊二烯和其他质体类异戊二烯主要通过 2-C-甲基-D-赤藓醇 4-磷酸（MEP）途径，由最近同化的光合产物产生。然而，当环境条件限制光合作用时，部分 MEP 途径的碳可以来自于质外体来源。质外体碳的流动取决于物种以及叶片发育和环境条件。MEP 途径和其他代谢途径之间的常见磷酸化中间产物的交换可以通过质体磷酸转运蛋白发生。C3 和 C4 碳中间产物可以为质体代谢做出贡献，包括光合作用和类异戊二烯合成。这些代谢过程的整合提供了代谢灵活性的一个例子，并导致为植物生长合成初级代谢物和为植物防御合成次生代谢物，从而在多种胁迫下有效利用环境资源。
