Regulation of plant carbon assimilation metabolism by post-translational modifications

The flexibility of plant growth, development and stress responses is choreographed by an intricate network of signaling cascades and genetic programs. However, it is metabolism that ultimately executes these programs through the selective delivery of specific building blocks and energy. Photosynthetic carbon fixation is the central pillar of the plant metabolic network, the functioning of which is conditioned by environmental fluctuations. Hence, regulation of carbon assimilation metabolism must be particularly versatile and rapid to maintain efficiency and avoid dysfunction. While changes in gene expression can adjust the global inventory and abundance of relevant proteins, their specific characteristics are dynamically altered at the post-translational level. Here we highlight studies that show the extent of the regulatory impact by post-translational modification (PTM) on carbon assimilation metabolism. We focus on examples for which there has been empirical evidence of functional changes associated with a PTM, rather than just the occurrence of PTMs at specific sites in proteins, as regularly detected in proteomic studies. The examples indicate that we are only at the beginning of deciphering the PTM-based regulatory network that operates in plant cells. However, it is becoming increasingly clear that targeted exploitation of PTM engineering has the potential to control the metabolic flux landscape as a prerequisite for increasing crop yields, modifying metabolite composition, optimizing stress tolerance, and even executing novel growth and developmental programs.

Automated summary

The flexibility of plant growth, development and stress responses is controlled by signaling cascades and genetic programs, while metabolism executes these programs through selective delivery of building blocks and energy. Photosynthetic carbon fixation is essential for plant metabolism, which is influenced by environmental fluctuations. The regulation of carbon assimilation metabolism requires versatility and rapidity to maintain efficiency. Post-translational modifications (PTMs) have a significant impact on carbon assimilation metabolism, altering protein characteristics and function. The exploitation of PTMs has the potential to control metabolic flux, influence crop yields, modify metabolite composition, optimize stress tolerance, and regulate growth and developmental programs.