Use of a bacterial composition comprising at least one plant growth-promoting bacterium from the Microbacterium genus, for producing biostimulant effects in seeds, seedlings and/or plants, comprising the step of priming said seeds, or seedlings or plants. The bacterial composition particularly comprises Microbacterium bacteria from clades 1 or 3, more particularly from certain new strains. The bacterial composition is particularly applied to a growth medium, for instance before transplantation. Very good results have been obtained for tomato plants.
