Licorice (Glycyrrhiza glabra L.), is an herbaceous perennial and has been used as
a flavoring agent in foods and medicinal remedies for years. Piriformospora indica, as an
endophyte Mycorrhizal-like fungus, promotes the growth and survival of plants
belonging to a number of species when exposed to various abiotic stresses, including
drought and salinity stress. Drought stress is a major constraint of crop productivity. The
goal of this research was the study of P. indica potential to colonize the roots of the
licorice plant and to enhance growth and photosynthesis capacity under drought stress.
This study was done as a factorial experiment in a completely randomized design with
three replications and was conducted in the greenhouse of Malayer university (Malayer).
The experimental factors included three fungal levels (inoculated with spore and
mycelium and non-inoculated) and two drought levels (F.C., 50% F.C.). The results
demonstrated that P. indica, promotes growth and confers drought resistance. Inoculation
of the plant with P.indica increased the biomass of licorice plants, as in inoculated plants
under drought stress total shoot and root dry weight was increased. The results showed
that the chlorophyll and carotenoid contents of P. indica-inoculated licorice leaves were
also higher than those of the uninoculated controls in drought stress. Higher chlorophyll
and carotenoid content and thus photosynthesis rates might accelerate carbohydrate
synthesis and thus growth of Glycyrrhiza glabra. These results suggest that P. indica is a
helpful symbiont for promoting licorice growth and drought resistance [1, 2].