Novel components of leaf bacterial communities of field-grown tomato plants and their potential for plant growth promotion and biocontrol of tomato diseases

ROMERO, FERNANDO MATIAS; MARINA, MARÍA; PIECKENSTAIN, FERNANDO LUIS

RESEARCH IN MICROBIOLOGY

ELSEVIER SCIENCE BV

Año: 2016 vol. 167 p. 222 - 233

0923-2508

This work aimed to characterize potentially endophytic culturable bacteria from leavesof cultivated tomato and analyze their potential for growth promotion and biocontrol ofdiseases caused by Botrytis cinerea and Pseudomonas syringae. Bacteria were obtained frominner tissues of surface-disinfected tomato leaves of field-grown plants. Analysis of 16SrRNA gene sequences identified bacterial isolates related to Exiguobacterium aurantiacum(isolates BT3 and MT8), Exiguobacterium spp.(isolate GT4), Staphylococcus xylosus (isolateBT5), Pantoea eucalypti (isolate NT6), Bacillus methylotrophicus (isolate MT3),Pseudomonas veronii (isolates BT4 and NT2), Pseudomonas rhodesiae (isolate BT2) andPseudomonas cichorii (isolate NT3). After seed inoculation, BT2, BT4, MT3, MT8, NT2 andNT6 were re-isolated from leaf extracts. NT2, BT2, MT3 and NT6 inhibited growth ofBotrytis cinerea and Pseudomonas syringae pv.tomato in vitro, produced antimicrobialcompounds and reduced leaf damage caused by B. cinerea. Some of these isolates alsopromoted growth of tomato plants, produced siderophores, the auxin indole-3-acetic andsolubilized inorganic phosphate. Thus, bacterial communities of leaves from field-growntomato plants were found to harbor potentially endophytic culturable beneficial bacteriacapable of antagonizing pathogenic microorganisms and promoting plant growth, which couldbe used as biological control agents and biofertilizers/biostimulators for promotion of tomatoplant growth.