Auxins are important plant regulators involved in many
growth and behavioral processes, including those
activated by Trichoderma spp. (Contreras et al., 2009).
Hexon et al. (2009) showed that Trichoderma spp.
produced indole-3-acetic acid (IAA) that promotes lateral
root formation. The enhanced plant growth by
Trichoderma (T. harzianum strain T22, T39 and A6)
might be due to the production of secondary metabolites
which may act as an auxin like compound (Vinale et al.,
2008a, b)