The present invention according to a firrst aspect relates to a Trichoderma longibrachiatum strain comprising an autologous nucleotide sequence coding for a protein having at least 70% sequence similarity with the amino acid sequence of SEQ ID NO: 1 and its use for the treatment of a plant. Further aspects of the invention relate to a protein derived from said strain, methods for producing the protein, the use of the protein for the treatent of a plant and compositions comprising a source of the protein of the invention. Yet Further aspects of the invention relate to seeds treated with a source of the protein and methods for growing plants incorporating the step of treating said plants with the composition of the invention.