Behind the “Cry for Help” response caused by plant pathogen infection

A group from State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China, etc. has reported about how to induce “cry for help” response to assemble disease suppressing and growth promoting rhizomicrobiome.
https://www.nature.com/articles/s41467-024-46254-3

The well-studied model pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 and its nonpathogenic derivatives (D36E, D36EFLC and D36EHPM) were used in this experiment using Arabidopsis as a model plant.

Treatment with either DC3000 or the derivatives increased the relative contents of long chain organic acids (LCOAs) and amino acids in root exudates. The bacterial phyla Proteobacteria (32.1%–38.3%) and Actinobacteria (15.4%–20.7%) were the most abundant groups in the rhizosphere, and the genus Devosia (belonging to phylum Proteobacteria) was enriched in the D36E and D36EFLC treatments. Interestingly, the abundance of genus Devosia was negatively correlated with L-malic acid and myristic acid in root exudates but positively correlated with 4-hydroxypyridine.

Finally, it was shown that the metabolites of D36E and D36EFLC alone are sufficient to induce a “cry for help” response. So, this study demonstrates the ability of nonpathogenic strains and their MAMPs to act as elicitors to induce the formation of a disease-suppressive soil legacy, which can potentially support agricultural applications.