Elucidation of the nematicidal mode of action of 3-octanol on the root-lesion nematode Pratylenchus penetrans

Abstract

The root-lesion nematode (RLN), Pratylenchus penetrans, is one of the most severe plant parasitic nematodes (PPN), responsible for productivity losses in a significant number of plant hosts. The chemical control of these PPNs relies on fumigants and non-fumigants compounds, which offer a systemic protection. Such control methods are costly and hazardous to the environment and to humans. Compounds naturally produced by plants may play an important role in nematode control. The aim of this study is to analyze the molecular response of P. penetrans to the nematicidal agent 3-octanol (C8H18O) using a De novo transcriptome assembly approach. Previous work showed that 3-octanol is a strong nematicide of P. penetrans causing 100% mortality in standard direct contact for 24h. The mode of action of this nematicide was studied at sub-lethal exposure for 30 min. Overall, the aliphatic alcohol 3-octanol induced the activation of detoxification mechanisms of P. penetrans with up-regulation of metabolic pathways related with metabolism of xenobiotics by CP450, steroid hormone synthesis, retinol metabolism, drug metabolism among others, while affecting ascorbate and aldarate metabolism, starch/sucrose metabolism and several signaling pathways related with cellular immune response. Understanding the defense mechanisms of P. penetrans against natural nematicides can lead to development of tailor- made control solutions.