Isolation, identification and evaluation of plant growth promotion effects of native fluorescent Pseudomonas from rhizophere soil of a Mentha × piperita plantation.

SANTORO, M., GIORDANO, W., BANCHIO, E.

Simposio; 32nd New Phytologist Symposium. Plant interactions with other organisms: molecules, ecology and evolution.; 2013

There are some bacteria living in rhizosphere capable of improve plant-growth, known as Plant- Growth Promoting Rhizobacteria (PGPR). In the last years, a mechanism has been described mediated by volatile organic compounds (VOCs) produces by rhizobacterias. Until this moment there are few studies about the effects of VOCs on aromatics plants. The aim of this work was to isolated PGPR bacteria and to evaluate growth promoting effects on mint mediate by emitted VOCs Fluorescent pseudomonads were isolated from rhizosphere of Mentha piperita. The activity of promoting plant growth and essential oils (EO) production was tested by direct inoculation and VOCs effects. For strains of the all isolated bacteria were selected, because produce an increase in plant growth parameters and EO yield. The profile of emitted VOCs was analysed by GC-MS. The compound emitted by isolated strains can be separated into two groups; one presented on all native bacteria analysed and the other characteristic of single bacteria. Direct inoculation produced an enhancement in biomass of root and number of leaves of plants of mint cultured in vitro. VOCs emission increase the total content of mint EO and some of the main compounds like: limonene, menthone, menthol. It is well known that EOs are produced as mechanism of defence and that some bacterial VOCs produce an ISR, we can suggest that the increase on EO production may be an improvement of aromatic plant defence.