Study Reveals Similarities and Differences in How Tomato Plants Recognize Fungal Pathogens Through Cf-4 and Cf-5 Proteins
Researchers compared how two tomato plant immune receptors, Cf-4 and Cf-5, respond to fungal pathogen effectors, finding they use shared initial signaling mechanisms but differ in downstream responses. Both receptors recognize specific secreted proteins from the fungus Fulvia fulva and trigger cell death to prevent infection. The findings suggest that the speed and intensity of immune responses don't determine how well plants resist the pathogen, which has implications for understanding plant immunity and breeding disease-resistant crops.
A bioRxiv preprint study examined how two receptor-like proteins (Cf-4 and Cf-5) in tomato plants initiate immune responses against the fungal pathogen Fulvia fulva. Although both receptors confer resistance to the fungus, Cf-4 triggers faster and stronger cell death than Cf-5. The researchers found that both receptors activate the same core upstream signaling components, including rapid MAPK activation, though Cf-5 maintains more sustained activation. Both pathogen effectors (Avr4 and Avr5) independently trigger reactive oxygen species bursts in the plant's extracellular space, and transcriptome analysis revealed a large shared set of differentially expressed genes alongside quantitative differences, with Cf-5 inducing broader transcriptional reprogramming. Despite these molecular differences, both receptors confer comparable levels of resistance to the fungus, demonstrating that the intensity and timing of cell death responses do not correlate with resistance robustness.
Limitations & open questions
The study's limitations and open questions include: whether findings in the model plant Nicotiana benthamiana fully translate to tomato physiology; the functional significance of the broader transcriptional reprogramming triggered by Cf-5; whether other Cf proteins (Cf-2, Cf-9) follow similar patterns; and the evolutionary advantages of maintaining different immune response kinetics despite equivalent resistance outcomes.
What different sources said
- bioRxivCenter
Cf-4- and Cf-5-triggered plant immunity: Similarities and differences
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