Abstract
In a world with a rapidly growing population, clear-cut solutions should be found to increase crop yield in order to provide enough food for everyone. However, abiotic stresses are among the most limiting factors to achieve this goal. A possible solution might come from studying the plant microbiota communities and their effects on plants under stress. Indeed, rhizophere and endosphere microbial communities are distinct from the surrounding soil, and these specific communities highly contribute to the health and growth of plants. We identified a beneficial plant microbe Enterobacter sp. SA187 that induces plant tolerance to abiotic stresses. However, the key genes for this beneficial interaction between the plant and the bacterium are unknown. Here we show that Ethylene Receptor Sensor 2 (ERS2) acts as a positive regulator of plant-bacterial interaction. We identified the ERS2 gene from a Genome-Wide Association study. When colonized with SA187, we found that mutant ers2 plants are compromised in fresh weight and beneficial index under salt stress conditions. Our results confirm the important role of ethylene signaling in this beneficial interaction to enhance plant stress tolerance of the model plant Arabidopsis in vitro and in open field agriculture of crops (de Zelicourt et al., 2018). Taken together, our work shows that ethylene is a key signal from beneficial bacteria to the host plant to enhance tolerance to abiotic stress thereby increasing yield and biomass.