Development of synthetic biology tools for the expression of recombinant proteins in rice plastids

There are proteins encoded by nuclear DNA that are synthesized with an N-terminal signal (Transit Peptide) that mediates interaction with of translocator complexes on plastid membranes and import. The characterization of TPs from species like rice supposes the creation of synthetic biology tools useful for cereal engineering.


In this work, we have used the TPs of four Arabidopsis thaliana proteins, three related to photosynthesis (chlorophyll a / b binding protein, Rubisco activase) and photoprotection (tocopherol cyclase) and one involved in the assimilation of ammonium into amino acids, and whose expression is more abundant in the root (ferredoxin-dependent glutamate synthase 2), to determine if they were capable of mediating the import of a recombinant protein in plastids of different tissues of a dicotyledonous and another monocotyledonous species.

Our results show that Arabidopsis photosynthetic protein TPs also mediate importation into plastids in callus, leaves and roots of rice, with almost 100% efficiency, providing new biotechnological tools that could be useful for the development of breeding strategies. cultures that require expression of recombinant proteins in a plastid-directed manner.

Confocal laser scanning microscopy images of A. thaliana leaf (left) and root (right) protoplasts expressing indicated TP-eGFP fusions. N.C. corresponds to nontransformed protoplasts.

Original Paper:

Eseverri, Á., Baysal, C., Medina, V., Capell, T., Christou, P., Rubio, L.M., Caro, E. 2020. Transit Peptides From Photosynthesis-Related Proteins Mediate Import of a Marker Protein Into Different Plastid Types and Within Different Species. Frontiers in Plant Science 11, 1474. DOI: 10.3389/fpls.2020.560701