Elevated CO2 enhances resistance to the BPMV virus in common bean

Elevated CO₂ enhances the degree of resistance to the BPMV virus in common bean

Development of a viral disease in a plant species requires a conducive environment. Therefore, changes in environmental factors, and more broadly, changes related to global climate change, can impact virus infection, replication, and transmission by biological vectors, possibly increasing or reducing the degree of disease.

In this new study published in the journal “Plant, Cell & Environment” by the GDYNPATH team coordinated by Valérie Geffroy, we assessed the impact of an elevated CO₂ concentration (eCO₂, 1000 ppm) on two genotypes of common bean (Phaseolus vulgaris L.), one susceptible and one resistant, infected with the bean pod mottle virus (BPMV, Comovirus siliquae). For both genotypes, plant growth, development, and physiology were not enhanced under eCO₂ in healthy plants at the stage of BPMV inoculation. In addition, the number of primary infection sites was reduced in both genotypes by eCO₂. Consistently, viral titer in inoculated leaves was lower, suggesting an enhanced resistance to BPMV in both genotypes under eCO₂. To investigate the underlying mechanisms, we studied the expression of genes involved in different antiviral immune pathways: salicylic acid (SA)‐signalling, RNA silencing, and PAMP‐triggered immunity (PTI) pathways. Under our experimental conditions, eCO₂ neither primed the SA‐ signalling pathway nor the PTI pathway, in both genotypes. However, eCO₂ seemed to prime the RNA silencing pathway in the resistant genotype, and to a lesser extent, in the susceptible genotype.

Overall, our results show that eCO₂ enhances the degree of resistance to BPMV in both resistant and susceptible genotypes of common bean and that this may be linked to the modulation of RNA silencing antiviral immune pathways.

21/10/2025