A bacteria beneficial in low nitrogen

A beneficial bacteria improves plant growth under low fertilization conditions

Developing alternatives to synthetic nitrogen fertilizers is a key challenge for reconciling agricultural productivity with reducing detrimental environmental impacts. In a study published in New Phytologist, scientists from the Institute of Plant Sciences-Paris Saclay (IPS2) demonstrated that Enterobacter sp. SA187, a non-nitrogen-fixing endophytic bacterium already known to enhance plant tolerance to various environmental stresses, can improve plant growth under low nitrogen conditions.

Using the model plant Arabidopsis thaliana, they showed that this bacterium strongly stimulates growth when the plant has access to very low levels of nitrate. This improvement is based on increased absorption and internal redistribution of nitrate, associated with an increased expression of genes encoding the high-affinity nitrate transporters NRT2.5 and NRT2.6. Using transcriptomic and genetic approaches, the study also reveals that this process is largely mediated by the activation of the phytohormone ethylene signaling pathway.

This work sheds new lights on how beneficial microorganisms can reprogram the transcriptome and plant development to optimize nitrogen use. It opens promising avenues for the development of more sustainable agricultural strategies based on microbial inputs to reduce the use of synthetic nitrogen fertilizers.

Simplified model of Enterobacter sp. SA187 impact on Arabidopsis thaliana under low N conditions SA187 inoculation promotes plant growth under low nitrate by modulating the expression of high-affinity nitrate transporters (HATS) through both ethylene-dependent and independent pathways. NRT2.5 is strongly upregulated in presence of SA187 in an EIN2-dependent manner in both shoots and roots, while NRT2.6 shows tissue-speciﬁc regulation: downregulated in shoots, and upregulated in roots, with a partial ethylene independence.

30/01/2026