Genetic Resistance Mechanisms in Rice Against Insect Pests

Rice employs a multilayered defence system against insect herbivores that integrates receptor‐mediated recognition of insect‐derived molecules, downstream signalling cascades, physical barriers and regulated cell responses. Key resistance (R) genes encode nucleotide‐binding leucine‐rich repeat receptors or lectin and short consensus repeat domain proteins that perceive insect effectors and activate plant immunity. This recognition triggers kinase cascades, hormone signalling and transcriptional reprogramming, leading to callose deposition in sieve elements, production of proteinase inhibitors and mobilisation of secondary metabolites. Autophagic pathways fine‐tune defence activation to limit growth penalties. Small RNAs and transcription factors further modulate gene networks in response to feeding. The identification and pyramiding of quantitative trait loci and cloned R genes have underpinned breeding of durable, broad‐spectrum resistance, offering a sustainable route to safeguard global rice yields against piercing‐sucking pests such as brown planthopper.

Research from Nature Portfolio

Recent studies have elucidated a tripartite rheostat in which a brown planthopper salivary protein binds a rice receptor‐like cytoplasmic kinase to suppress basal defences but is recognised by an intracellular NB‐LRR receptor, BPH14, restoring immunity; selective autophagy of the effector prevents chronic defence activation and growth inhibition. Foundational work on BPH18, a CC-NBS-NBS-LRR gene from wild rice, revealed its endomembrane localisation in phloem cells and unique dual NBS architecture that confers durable planthopper resistance. Another seminal discovery is Bph32, encoding an SCR domain protein highly expressed at feeding sites, which reduces planthopper ingestion when introgressed into susceptible varieties, highlighting the diversity of receptor classes mediating host resistance.

Genetic Resistance Mechanisms in Rice Against Insect Pests publication trend

The graph below shows the total number of articles in genetic resistance mechanisms in rice against insect pests across all publications each year (not limited to Nature Index journals).

Technical terms

Nucleotide-binding leucine-rich repeat receptor (NB-LRR): Intracellular protein that recognises insect or pathogen effectors and initiates immune signalling.

Receptor-like kinase (RLK): Membrane‐anchored enzyme that perceives extracellular signals and activates downstream defence pathways.

Autophagy: Selective degradation of cellular components that regulates immune receptor and effector levels to balance defence and growth.

MicroRNA (miRNA): Small non-coding RNA that post-transcriptionally regulates gene expression, modulating resistance pathways.

Quantitative trait locus (QTL): Genomic region harbouring genes that contribute to variation in complex traits such as pest resistance.

Callose deposition: Rapid synthesis and accumulation of β-1,3-glucan at sieve plates to block phloem feeding by piercing-sucking insects.

References

1. A tripartite rheostat controls self-regulated host plant resistance to insects. Nature (2023).
2. Map-based Cloning and Characterization of the BPH18 Gene from Wild Rice Conferring Resistance to Brown Planthopper (BPH) Insect Pest. Scientific Reports (2016).
3. Bph32, a novel gene encoding an unknown SCR domain-containing protein, confers resistance against the brown planthopper in rice. Scientific Reports (2016).
4. OsmiR319-OsPCF5 modulate resistance to brown planthopper in rice through association with MYB proteins. BMC Biology (2024).
5. Integrated transcriptomics and metabolomics analysis provide insight into the resistance response of rice against brown planthopper. Frontiers in Plant Science (2023).
6. Recent Advances in Molecular Mechanism and Breeding Utilization of Brown Planthopper Resistance Genes in Rice: An Integrated Review. International Journal of Molecular Sciences (2023).