Nep1-Like Protein Elicitation in Plant-Pathogen Interactions

Nep1-like proteins (NLPs) are a ubiquitous class of microbial effector molecules secreted by bacteria, fungi and oomycetes. Initially characterised by their necrosis- and ethylene-inducing activities, NLPs also act as microbe-associated molecular patterns that activate pattern-triggered immunity in eudicot plants. Recognition of conserved nlp peptide motifs at the plant cell surface by specialised receptor-like proteins leads to rapid defence responses, including reactive oxygen species bursts, cell wall reinforcement and transcriptional reprogramming. While cytotoxic NLPs contribute to virulence in necrotrophic and hemibiotrophic pathogens by targeting specific sphingolipid receptors in the plasma membrane, noncytotoxic NLP variants appear to have diversified functions, ranging from immune modulation to subtle host adaptation. Structural studies reveal that key loop regions and conserved peptide patterns within the NLP fold determine both membrane interaction and immunogenic potency. The global significance of NLP elicitation spans fundamental insights into plant innate immunity and offers practical applications, from the design of novel disease-resistant crops to the development of targeted antimicrobial agents that block NLP activity.

Research from Nature Portfolio

Recent studies have shown that the rice blast fungus Magnaporthe oryzae encodes a small family of NLPs capable of inducing cell death and reactive oxygen species production in tobacco, yet targeted deletion of all family members did not compromise pathogenicity on rice. This highlights functional redundancy among NLPs and suggests that their virulence contribution may be host-specific or context-dependent. Another investigation elucidated the role of Arabidopsis receptor-like protein 23 in pre-invasive immunity to the grey mould pathogen Botrytis cinerea. This work demonstrated that RLP23 recognition of conserved nlp peptides at early infection stages is required for reactive oxygen species bursts and effectively restricts fungal ingress, underscoring the importance of NLP perception in basal defence.

Nep1-Like Protein Elicitation in Plant-Pathogen Interactions publication trend

The graph below shows the total number of articles in nep1-like protein elicitation in plant-pathogen interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Nep1-like proteins (NLPs): A family of secreted microbial effectors that induce necrosis in plants and function as microbe-associated molecular patterns.

Pattern-triggered immunity (PTI): The plant immune response activated upon recognition of conserved pathogen- or damage-associated molecular patterns at the cell surface.

Receptor-like proteins (RLPs): Cell-surface proteins lacking intracellular kinase domains that bind pathogen-derived peptides and recruit co-receptors to initiate defence signalling.

Glycosylinositol phosphorylceramides (GIPCs): Plant-specific sphingolipids that serve as binding partners for NLPs during membrane interaction and pore formation.

Reactive oxygen species (ROS): Highly reactive molecules produced by plant cells as an early defence mechanism that can strengthen cell walls and signal downstream immune responses.

References

1. A Conserved Peptide Pattern from a Widespread Microbial Virulence Factor Triggers Pattern-Induced Immunity in Arabidopsis. PLOS Pathogens (2014).
2. Molecular basis for functional diversity among microbial Nep1-like proteins. PLOS Pathogens (2019).
3. Nep1-like proteins as a target for plant pathogen control. PLOS Pathogens (2021).
4. The Nep1-like protein family of Magnaporthe oryzae is dispensable for the infection of rice plants. Scientific Reports (2017).
5. RLP23 is required for Arabidopsis immunity against the grey mould pathogen Botrytis cinerea. Scientific Reports (2020).
6. An oomycete NLP cytolysin forms transient small pores in lipid membranes. Science Advances (2022).
7. Type 2 Nep1-Like Proteins from the Biocontrol Oomycete Pythium oligandrum Suppress Phytophthora capsici Infection in Solanaceous Plants. Journal of Fungi (2021).