Fuente: WIPO "tomato" Described herein are polypeptides having plant biostimulant activity, bacterial strains producing these polypeptides and uses thereof for promoting plant growth. In embodiments the polypeptide comprises the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3. In embodiments the polypeptides are sactipeptides comprising one to four Cys-to-alpha carbon bond(s). The peptides are particularly useful for plant biostimulation. Also described are bacterial extracts coprising the peptides, nucleic acid molecules encoding these peptides and bacterial strains producing the same.