Abstract:

NLPs[necrosis-and ethylene-inducing peptide 1 (Nep1)-like proteins] are a type of apoplast secreted protein, which exist in a variety of phytopathogens, and play an important role during plant-pathogen interactions. According to structural characteristics, NLP proteins are divided into three types: Ⅰ, Ⅱ and Ⅲ, with cytotoxic and noncytotoxic forms. Cytotoxic NLPs bind to NTCD4 protein to facilitate oligomerization of NLP proteins, resulting in cell death and disease susceptibility in eudicots, but not monocots. However, the function of noncytotoxic NLP proteins remains unclear. NLPs can also act as microbe-associated molecular patterns(MAMP)to trigger plant immunity. Many plants have evolved immune systems that specifically recognize NLP proteins, e.g., Arabidopsis thaliana recognizes the conserved peptide nlp20/24 of type Ⅰ NLP proteins via the receptor-like protein RLP23, thereby stimulating immune responses. This article reviewed the research progress on NLPs, such as protein structures, gene expression patterns, mechanisms of pathogenicity and host recognition, to provide a theoretical basis and reference for further research on pathogen-host interactions and disease prevention and control.

Key words: phytopathogens, NLPs, cytotoxic, immunity, pathogenic mechanism