potential to produce bioactive secondary metabolites that are involved in chemical
defense of host plants, stress tolerance and antimicrobial activities (Arnold et al.
2003 ; Gunatilaka 2006 ; Debbab et al. 2012 ; Kusari et al. 2013 ;2014a; Li et al.
2015 ; Wang et al. 2015 , 2016 ). Normal screening of endophytes under laboratory
conditions results in production of certain natural products, but cryptic bioactive
metabolites often require certain triggering factors (Scherlach and Hertweck 2009 ;
Kusari et al. 2013 ,2014c). Thus, antagonism and antifungal activity was employed
as a triggering factor to estimate the biocontrol potential of endophytes in aiding
chemical defense to host plants against invading pathogens. Further, the results
were in complete agreement to the well-known OSMAC approach (Bode et al.
2002 ; Kusari et al. 2012 ), whereby the different culture parameters, nutrient con-
ditions and pathogen stress were responsible for the biosynthesis of secondary
metabolites or their precursors by endophytes. Additionally, such investigations
pointed towards the capability of endophytes to produce cryptic metabolites under
certain elicitation conditions, which might be useful in production of agriculturally
valuable compounds against pathogens and pests. Recent investigations on endo-
phytes harbored in various medicinally important plants, other thanCannabis, have
utilized the OSMAC concept for the production of bioactive target and non-target
compounds (Kharwar et al. 2011 ; Debbab et al. 2012 ; Kusari et al. 2012 , 2013 ,
2014b,c; Li et al. 2015 ; Wang et al. 2015 , 2016 ), effective against potentially
harmful pathogens, pests and associated epiphytes. Therefore, employing OSMAC
approach could exploit endophytic microorganisms as a sustainable resource of
bioactive natural products with implications in agricultural and pharmaceutical
sectors.
20.4 Screening of Endophytic Microorganisms Living
inCannabisPlants Conferring Plant Adaptation
and GrowthEndophytic microorganisms have been bioprospected for the capability to protect
plants from biotic and abiotic stress, induce plant growth and development
(Redman et al. 2002 ; Rodrigues et al. 2004 , 2008 ; Rodrigues and Redman 2008 ;
Hamilton et al. 2012 ; Kusari et al. 2013 ). Recent studies on bacterial endophytes
fromCannabisplants growing in the wild (Afzal et al. 2015 ) have demonstrated
their capability to provide stress tolerance from different salt concentrations, pro-
duction of growth hormones like Indole-3-acetic acid (IAA), inorganic phosphate
solubilization and even plant and fungal cell wall degradation. Since ages, plants
are known to withstand stress conditions and constantly coevolve to initiate
responses against such conditions. In spite of such significant advances, plant salt
stress possesses a threat to agricultural lands. Salt stress is a condition whereby
increase in the amount of salt causes plant growth inhibition and even death. In the
study conducted by Afzal et al. ( 2015 ), bacterial endophytic isolates ofCannabis
426 P. Kusari et al.