[Research progress in inducible expression regulation systems in photosynthetic cyanobacteria]

Cyanobacteria, as a group of prokaryotic photosynthetic microorganisms, have recently garnered widespread attention in the fields of synthetic biology and green biomanufacturing due to their ability to utilize light energy and carbon dioxide for autotrophic growth. The development of efficient and controllable gene expression regulation systems is a crucial step for achieving precise control over cyanobacterial metabolic engineering and efficient production of heterologous compounds. This review summarizes recent advances in inducible gene expression regulation systems developed for cyanobacteria, with a focus on commonly used chemical induction systems and optogenetic control systems, as well as their applicability and regulatory characteristics across various cyanobacterial strains. In addition, we compare key parameters of these systems, including their induction strength, basal expression levels, and expandability, while discussing practical challenges such as leaky expression, system stability, and host specificity. Finally, this paper provides an outlook on future trends in the development of novel inducible expression systems, modular regulatory circuits, and environmentally responsive expression systems through synthetic biology approaches, offering a reference for constructing more efficient, tunable, and environmentally friendly gene expression regulation systems in cyanobacteria.