# Arabidopsis protein CAR1 reinforces stomatal immunity against Pseudomonas syringae effector AvrE1

- Published: 2026-11-05 23:11 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: stomatal immunity, CAR1 resistance protein, AvrE1 effector, Pseudomonas syringae, Arabidopsis thaliana, guard cells, type III effector, plant pathogen entry
- URL: https://realtech.media/news/rt-b9d88939e1c3c8f54e925225_arabidopsis_protein_car1/

**In Arabidopsis thaliana, the resistance protein CAR1 recognizes the effector AvrE1 and prolongs stomatal immunity, limiting leaf invasion by natural P. syringae isolates.**

![Arabidopsis protein CAR1 reinforces stomatal immunity against Pseudomonas syringae effector AvrE1](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/cfcd36941afd075c.jpg)
*Tian, M.; Yu, R.; Yang, W,; Guo, S.; Liu, S.; Du, H.; Liang, J.; Zhang, X., Wikimedia Commons, CC BY 4.0*

Researchers reported in Science Advances that the resistance protein CAR1 in Arabidopsis thaliana reinforces stomatal immunity after recognizing AvrE1, a type III effector of the bacterial pathogen Pseudomonas syringae [1]. The pathogen must enter the leaf interior through natural openings such as stomata to cause disease, and plants restrict entry by closing stomata upon non-self recognition. P. syringae counters this with a range of toxins and effectors.

CAR1 expression is enriched in guard cells, and its activation prolongs the effective duration of stomatal immunity [1]. CAR1 also prevented invasion of leaf tissue by natural isolates of P. syringae [1]. According to the authors, CAR1-mediated stomatal immunity against the conserved effector AvrE1 forms a broadly significant barrier to host accessibility by the pathogen.

## Sources

1. [Science Advances](https://doi.org/10.1126/sciadv.aei5129)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b9d88939e1c3c8f54e925225_arabidopsis_protein_car1/