Structure, biogenesis, and evolution of thylakoid membranes

Area of Science:

• Biochemistry
• Plant Biology
• Microbiology

Background:

• Specialized thylakoid membranes (TMs) in cyanobacteria, algae, and plants are crucial for converting sunlight into chemical energy via photosynthesis.
• These membranes contain Photosystem II (PSII) and Photosystem I (PSI), essential protein-pigment complexes for oxygenic photosynthesis.

Purpose of the Study:

• To provide an in-depth review of thylakoid membrane architectures across phototrophs.
• To explore the evolutionary determinants shaping TM forms and their biogenesis.
• To define the principles guiding the evolution of these bioenergetic membranes.

Main Methods:

• Literature review of TM structures and functions.
• Analysis of evolutionary adaptations in photosynthetic electron transport and light-harvesting systems.
• Synthesis of recent findings on TM biogenesis and spatial organization.

Main Results:

• TMs exhibit structural diversification across phototrophs, from simple structures in cyanobacteria to complex networks in vascular plants.
• While core photosynthetic machinery remains conserved, light-harvesting antenna systems show significant adaptation.
• Vascular plants possess intricate thylakoid networks, including stacked grana and unstacked stroma thylakoids.

Conclusions:

• The evolution of TMs involved diversification in structure, particularly in light-harvesting antennae, while preserving core photosynthetic functions.
• Understanding TM architecture, biogenesis, and maintenance provides insights into the evolution of bioenergetic membranes.
• This review highlights the principles governing TM evolution in phototrophic organisms.