Function of D-amino acids on plastid division in plants

尽管D-氨基酸是细菌肽聚糖的基本成分，但人们认为D-氨基酸在生物体中的使用是有限制的。我们发现，在小球藻苔藓中还保留有合成胞外肽聚糖的途径。在这项研究中，我们分析了一个细菌D-丙氨酸-D-丙氨酸连接酶(DDL)的同源物。我们获得了一个PpDdl基因敲除系，其表型表现为大量的叶绿体，在培养基中添加D-丙氨酰-D-丙氨酸可以抑制叶绿体的表型。这些结果表明，由PpDd1合成的D-丙氨酰-D-丙氨酸是白杨叶绿体分裂所必需的。

It is thought that usage of D-amino acids in organisms is restrictive, although D-aminoacids are essential components of bacterial peptidoglycan. We found that plastidpeptidoglycan synthesis pathway remains in the moss Physcomitrella patens. In this study,we analyzed a P. patens homolog of bacterial D-alanine-D-alanine ligase (Ddl). Wegenerated a PpDdl knockout line, and its phenotype showed a few macrochloroplasts.D-alanyl-D-alanine supplemented in a medium could suppress chloroplast phenotype. Theseresults suggested that D-alanyl-D-alanine synthesized with PpDdl is essential forchloroplast division in P. patens.