20.1 Introduction
In the last decades, extensive studies on endophytic microorganisms harboring a
plethora of plants have led to the possibility of unraveling their intricate association
with host plants, associated endophytes and epiphytes, pathogens and even herbi-
vores (Kusari and Spiteller 2012 ; Kusari et al. 2013 ,2014b,c; Newman and Cragg
2015 ). Endophytic microorganisms, commonly called“endophytes”, reside within
the internal tissues of plants maintain a mutualistic association for at least a part of
their lifecycle, without causing any disease (Bacon and White 2000 ; Kusari et al.
2012 ; 2013 ,2014a,b,c,d,e). In this way, endophytes constantly coevolve with
their host plant(s) and associated microorganisms that enable them to develop
various functional capabilities for survival such as production of antagonistic vir-
ulence factors against invading pathogens, as well as development of strategies to
bypass or attenuate the virulence of phytopathogens. Further, endophytes are
known to produce various bioactive secondary metabolites, encompassing almost
all kinds of chemical scaffolds, some of which are occasionally mimetic to the
associated host plants and aid in host plantfitness against different biotic and abiotic
factors (Rodriguez et al. 2004 , 2008 ; Waller et al. 2005 ;Márquez et al. 2007 ;
Porras-Alfaro and Bayman, 2011 ; Kusari et al.2014b,c,d,e). Interestingly, it has
now emerged that endophytes play important roles in their ecological niches not as
axenic forms but as endophytic microbial communities. These include, for example,
production of bioactive secondary metabolites that directly act as chemical defense
compounds for host plants, aiding in host plantfitness, development and/or traf-
ficking of pathogenic signals, and involvement in host plant gene regulations and
metabolic processes (Hosni et al. 2011 ; Liu et al. 2012 ; Cornforth et al. 2014 ;
Kusari et al.2014d, 2016 ; Wang et al. 2015 , 2016 ). Concomitantly, plants serve as
highly-selective and specific ecological niche for harboring and maintaining
interactions with selected endophytic microflora. Investigations on every plant
species till date have led to identifying and characterizing both fungal and bacterial
endophytes (Staniek et al. 2008 ; Debbab et al. 2012 ; Li et al. 2012 ; Kusari et al.
2012 ,2014b,c).
Medicinal plants likeCannabis sativaL. have also been reported to harbor
endophytes (Gautam et al. 2013 ; Qadri et al. 2013 ; Kusari et al. 2013 ,2014a,b,e).
C. sativa (Cannabaceae) is an annual herbaceous plant known to contain
cannabinoids, terpenoids,flavonoids and lignans as secondary metabolites (ElSohly
and Slade 2005 ; Taura et al. 2007 ; Flemming et al. 2007 ; Flores-Sanchez et al.
2009 ; Kusari et al. 2013 ,2014b). These constituents have innumerable therapeutic
potencies ranging from analgesic, anti-spasmodic, anti-tremor, anti-inflammatory,
antioxidant, immunosuppressive, anti-nociceptive, antiepileptic, anti-depressive to
even antineoplastic (Carchman et al. 1976 ; Williamson and Evans 2000 ; Gomes
et al. 2008 ; Flores-Sanchez et al. 2009 ; Grotenhermen and Müller-Vahl 2012 ;
Kusari et al. 2013 , 2014b). Taking endophytic microflora into consideration,
C. sativaplants have been bioprospected for harboring endophytes with the goal of
evaluating their potential benefits in agricultural and pharmaceutical sectors.
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