Receptor-Like Kinases in Plant Stress Responses

Receptor-like kinases (RLKs) constitute one of the largest protein families in plants, mediating perception and transduction of environmental cues across the plasma membrane. These transmembrane receptors comprise an extracellular sensor domain, a single-pass transmembrane helix and a cytoplasmic kinase domain that initiates phosphorylation cascades. Among RLKs, leucine-rich repeat RLKs (LRR-RLKs) represent the most abundant subfamily, with diverse roles in development and immunity. Cysteine-rich receptor-like kinases (CRKs) bearing DUF26 motifs have emerged as crucial regulators of oxidative stress and pathogen defence. Through ligand binding and dimerisation, RLKs activate downstream signalling modules that modulate gene expression, stomatal aperture and hormone pathways. Functional redundancy within large RLK subfamilies masks individual contributions, yet recent genetic, biochemical and computational approaches have begun to unravel specific receptor–ligand pairs involved in drought, salinity, cold and biotic challenges. The dynamic modulation of RLK networks enables integration of abiotic and biotic signals, balancing growth and defence. Given their central position in stress signalling, RLKs offer promising targets for engineering climate-resilient crops and improving agricultural productivity worldwide.

Research from Nature Portfolio

Recent studies have used deep learning to annotate kinases and phosphatases directly from protein sequences in non-model species. This approach enabled de novo inference of phosphorylation signalling cascades under cold stress in soybean, identifying specific RLKs as key temperature regulators. Extension of these predictions to rice, maize, sorghum and wheat highlighted conserved receptor functions in diverse crops, offering a scalable framework to dissect kinase–substrate interactions and inform breeding strategies for thermal tolerance.

Receptor-Like Kinases in Plant Stress Responses publication trend

The graph below shows the total number of articles in receptor-like kinases in plant stress responses across all publications each year (not limited to Nature Index journals).

Technical terms

Receptor-like kinase (RLK): Transmembrane protein with extracellular sensor and intracellular kinase domains that perceives external signals and initiates phosphorylation cascades.

Leucine-rich repeat receptor-like kinase (LRR-RLK): Largest RLK subfamily defined by tandem leucine-rich repeats in the extracellular domain for ligand recognition.

Cysteine-rich receptor-like kinase (CRK): RLK subgroup characterised by DUF26 motifs implicated in reactive oxygen species sensing and stress signalling.

Domain of Unknown Function 26 (DUF26): Conserved extracellular motif found in CRKs that mediates redox-dependent ligand interactions.

Reactive oxygen species (ROS): Chemically reactive molecules derived from oxygen that serve as signalling agents during stress responses.

Phosphorylation cascade: Sequential activation of kinase enzymes by phosphate transfer that propagates and amplifies cellular signals.

References

1. Functional annotation of proteins for signaling network inference in non-model species. Nature Communications (2023).
2. Origin and diversification of leucine-rich repeat receptor-like protein kinase (LRR-RLK) genes in plants. BMC Ecology and Evolution (2017).
3. Large-Scale Phenomics Identifies Primary and Fine-Tuning Roles for CRKs in Responses Related to Oxidative Stress. PLOS Genetics (2015).
4. Transcriptional regulation of the CRK/DUF26 group of Receptor-like protein kinases by ozone and plant hormones in Arabidopsis. BMC Plant Biology (2010).