Abstract:

Peptidoglycan (PG) is an important component of the bacterial cell wall, and its biosynthesis is catalyzed by a series of enzymes. Since 2006, studies have shown that peptidoglycans are also present in chloroplast membranes of early land plants including Physcomitrium patens, and the genes encoding enzymes in PG biosynthesis pathway are well-conserved in the genomes of plants such as P. patens and tomato. PG tightly affects the division of chloroplasts and disrupting the functions of the PG biosynthetic genes leads to the development of giant chloroplasts in plants. In seed plants, whether PG is present in plastids and functions similarly in regulating cell division remains unclear. Despite that our knowledge about the biological roles of PG in plant chloroplasts has expanded, its physiological significance and the molecular mechanism remain to be elucidated. In addition, as the key material compositions of PG, the synthesis, metabolism and transport of D-amino acids may also influence PG synthesis. The application of visual detection technology also promotes the development of PG biology in plant plastids. Whether peptidoglycan exists in seed plants, and what are the biological functions and mechanisms of peptidoglycan in seed plants, should be investigated in the near future.

Key words: plant, peptidoglycan, plastid, D-amino acid, visualization