Melatonin production by rhizobacteria native strains: Towards sustainable plant growth promotion strategies

JOFRE, FLORENCIA; MAMMANA, SABRINA B.; LOPEZ APPIOLAZZA, MARTIN; M. FERNANDA SILVA; GOMEZ, FEDERICO J. V.; COHEN, ANA

PHYSIOLOGIA PLANTARUM

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023 vol. 175 p. 1 - 10

0031-9317

In the current context of climate change and water deficit, the selection of nativebeneficial microorganisms, such as plant growth-promoting rhizobacteria (PGPR), hasbecome a trend for sustainable agriculture due to their ability to improve plant–bacteria interaction with a minimal adverse effect on the soil microbiota compared tocommercial PGPR. Until now, the production of phytohormones like melatonin(MT) by native PGPR and their effect on endogenous MT levels in plants have beenpoorly studied. MT is a ubiquitous phytohormone that protects plants against bioticand abiotic stress by improving the tolerance of stressed plants. In this work, the production of MT by two native PGPR, Enterobacter 64S1 and Pseudomonas 42P4, wasevaluated and both PGPR were applied in Arabidopsis thaliana plants grown underdrought conditions to assess the inoculation effects. Parameters such as plantgrowth, leaf cellular membrane damage, leaf protective compounds, and endogenousMT levels under drought and irrigation conditions were evaluated. The results demonstrated that the native strains Pseudomonas 42P4 and Enterobacter 64S1 produceMT and increase the content of endogenous MT in A. thaliana plants under drought.These native strains improved the tolerance of arabidopsis plants to drought by preventing oxidative and membrane damages and improving plant growth. To the bestof our knowledge, this is the first report on MT production by native PGPR and theireffects on endogenous MT levels in arabidopsis plants, setting the bases to elucidatethe role of native PGPR on water deficit conditions.