Carbonic anhydrases CA1 and CA4 function in atmospheric CO2-modulated disease resistance

Yeling Zhou,Anja J H Van Dijken,Irene A Vroegop-Vos,Corné M J Pieterse,Cyril Zipfel,Saskia C M Van Wees,Dieuwertje Van Der Does

doi:10.1007/s00425-020-03370-w

Yeling Zhou, Anja J H Van Dijken + Show 5 more

Open Access

https://doi.org/10.1007/s00425-020-03370-w

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Abstract

Main conclusionCarbonic anhydrases CA1 and CA4 attenuate plant immunity and can contribute to altered disease resistance levels in response to changing atmospheric CO2 conditions.β-Carbonic anhydrases (CAs) play an important role in CO2 metabolism and plant development, but have also been implicated in plant immunity. Here we show that the bacterial pathogen Pseudomonas syringae and application of the microbe-associated molecular pattern (MAMP) flg22 repress CA1 and CA4 gene expression in Arabidopsis thaliana. Using the CA double-mutant ca1ca4, we provide evidence that CA1 and CA4 play an attenuating role in pathogen- and flg22-triggered immune responses. In line with this, ca1ca4 plants exhibited enhanced resistance against P. syringae, which was accompanied by an increased expression of the defense-related genes FRK1 and ICS1. Under low atmospheric CO2 conditions (150 ppm), when CA activity is typically low, the levels of CA1 transcription and resistance to P. syringae in wild-type Col-0 were similar to those observed in ca1ca4. However, under ambient (400 ppm) and elevated (800 ppm) atmospheric CO2 conditions, CA1 transcription was enhanced and resistance to P. syringae reduced. Together, these results suggest that CA1 and CA4 attenuate plant immunity and that differential CA gene expression in response to changing atmospheric CO2 conditions contribute to altered disease resistance levels.

Highlights

Plants have evolved a complex immune system to regulate survival from attack by pathogenic microbes and herbivorous insects
We found that differential expression of CA1 under different atmospheric C O2 conditions is correlated with an altered level of disease resistance against P. syringae and that CA1 and CA4 are required for the effects of C O2 on disease resistance against P. syringae
We first monitored the expression of CA1 and CA4 upon P. syringae infection of Arabidopsis cultivated under ambient C O2 conditions

Summary

Introduction

Plants have evolved a complex immune system to regulate survival from attack by pathogenic microbes and herbivorous insects. Upon perception of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs), defense responses are activated, including stomatal closure, production of reactive oxygen species, MAP kinase activation, hormonal signaling, and massive transcriptional reprogramming, which leads to the production of defensive compounds that limit pathogen ingress (Tsuda and Katagiri 2010; Zipfel and Robatzek 2010; Couto and Zipfel 2016). These induced signal outputs collectively lead to pattern-triggered immunity (PTI), which forms the first layer of plant defense to invading microbes. To produce climate resilient crops in the future, it is important to understand how changes in atmospheric C O2 levels impact plant–microbe interactions

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