Mechanistic insights toward identification and interaction of plant parasitic nematodes: A review

Nematode identification serves as an important parameter to study their behaviour, importance and pathogenicity. Application of classical morphometric based identification methods prove to be lacking due to insufficient knowledge on morphological variations among closely related taxa. Molecular approaches such as DNA and protein-based information, microarray, probing, sequence-based methods and others have been used to supplement morphology-based methods for nematode identification. Ascarosides and certain protein-based nematode-associated molecular patterns (NAMPs), can be perceived by the host plants, and can initiate a signalling cascade. This review primarily emphasizes on an updated account of different classical and modern tools used for the identification of nematodes. Besides we also summarize the mechanism of some important signalling pathways which are involved in the different plant nematode interactions. Nematodes constitute most diverse and least studied group of soil inhabiting invertebrates. They are ecologically and physiologically important, however, wide range of nematodes show harmful impact on the individuals that live within their vicinity. Plant parasitic nematodes (PPNs) are transparent, pseudocoelomate, free living or parasitic microorganisms. PPNs lack morphometric identification methods due to insufficient knowledge on morphological variations among closely related taxa. As such, molecular approaches such as DNA and protein-based information, microarray, probing, sequence-based methods and others have been used to supplement morphology-based methods for their identification. To invade the defense response of different plant species, parasitic nematodes have evolved different molecular strategies. Ascarosides and certain protein-based nematode-associated molecular patterns (NAMPs), can be perceived by the host plants, and can initiate a signaling cascade. To overcome the host confrontation and develop certain nematode feeding sites, some members can inject effectors into the cells of susceptible hosts to reprogram the basal resistance signaling. This review primarily emphasizes on an updated account of different classical and modern tools used for the identification of PPNs. Besides we also summarize the mechanism of some important signaling pathways which are involved in the different plant nematode interactions.