Harnessing Chlamydomonas reinhardtii for advanced chloroplast genetic engineering

The chloroplast genome represents an attractive target for genetic engineering. Due to its
prokaryotic origin, the molecular biology context in chloroplasts might offer features that nuclei
are naturally unable to provide, such as multicistronic expression, site-specific transgene
insertion and avoidance of silencing mechanisms for transgene expression. Unfortunately, these
same features have contributed to difficulties for advancing into chloroplast genetic engineering,
which have become a challenge even decades after its first successful transformation. This has
been seen particularly in Chlamydomonas reinhardtii, which has been a promising alternative
for prototyping chloroplast genetic engineering of higher plants. The specific factors affecting
chloroplast transgene expression in C. reinhardtii are still not well understood, hindering the
development of robust molecular biology tools for chloroplast engineering. To deal with these
constraints, researchers have focused on the generation of reliable selection markers and
expression reporters, widening the availability of proper gene regulatory elements, and the
generation of different strategies to facilitate chloroplast transformation. This talk attempts to
highlight that recent advances in these research fields shed light to the molecular biology
functioning of the chloroplast in C. reinhardtii, as well as providing tools that facilitate chloroplast
engineering for the further development of novel biotechnology applications.