Entomopathogenic nematodes of the genera Steinernema and Heterorhabditis, along with their bacterial symbionts from the genera Xenorhabdus and Photorhabdus, respectively, are important biological control agents against agricultural pests. Rapid progress in the development of genomic tools has catalyzed a transformation of the systematics of these organisms, reshaping our understanding of their phylogenetic and cophlylogenetic relationships. In this review, we discuss the major historical events in the taxonomy and systematics of this group of organisms, highlighting the latest advancements in these fields. Additionally, we synthesize information on nematode-bacteria associations and assess the existing evidence regarding their cophylogenetic relationships.

• Keywords
• Beneficial microorganisms, Biological control agents, Entomopathogens, Phylogeny, Systematics, Taxonomy,
• Publication type
• Journal Article MeSH
• Review MeSH

The Photorhabdus species is a Gram-negative bacteria of the family Morganellaceae that is known for its mutualistic relationship with Heterorhabditis nematodes and pathogenicity toward insects. This study is focused on the characterization of the recombinant lectin PLL3 with an origin in P. laumondii subsp. laumondii. PLL3 belongs to the PLL family of lectins with a seven-bladed β-propeller fold. The binding properties of PLL3 were tested by hemagglutination assay, glycan array, isothermal titration calorimetry, and surface plasmon resonance, and its structure was determined by X-ray crystallography. Obtained data revealed that PLL3 binds similar carbohydrates to those that the other PLL family members bind, with some differences in the binding properties. PLL3 exhibited the highest affinity toward l-fucose and its derivatives but was also able to interact with O-methylated glycans and other ligands. Unlike the other members of this family, PLL3 was discovered to be a monomer, which might correspond to a weaker avidity effect compared to homologous lectins. Based on the similarity to the related lectins and their proposed biological function, PLL3 might accompany them during the interaction of P. laumondii with both the nematode partner and the insect host.

• Keywords
• O-methylated saccharides, Photorhabdus, l-fucose, lectin,
• MeSH
• Bacterial Proteins chemistry   genetics   metabolism   MeSH
• Fructose metabolism   MeSH
• Calorimetry MeSH
• Crystallography, X-Ray MeSH
• Lectins chemistry   genetics   metabolism   MeSH
• Photorhabdus metabolism   MeSH
• Surface Plasmon Resonance MeSH
• Recombinant Proteins chemistry   metabolism   MeSH
• Protein Structure, Secondary MeSH
• Binding Sites MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bacterial Proteins MeSH
• Fructose MeSH
• Lectins MeSH
• Recombinant Proteins MeSH