therapeutics would also avoid the undesirable dramatic alterations of the host
microbiota that are associated with current antibiotics (Clatworthy et al. 2007 ; Hong
et al. 2012 ; Rajesh et al.2014b; Kusari et al. 2015 ). Additionally, genetically
transforming endophytes with quorum quenching genes likeaiiA can further
enhance the possibility of attenuating virulence factors. Moreover, plants are well
known to produce molecules that mimic the quorum autoinducers (Teplitski et al.
2011 ). Similarly, endophytic isolates capable of quenching might be checked for
the production of autoinducer-like molecules for interacting with pathogens in the
near vicinity, maintaining their colonization within host plants and subsequently
counteracting those pathogens.
20.6 Strategies for Discovering Endophytic Microbial
Community Harbored in Plants with Similar
Secondary Metabolites:Radula marginata
as an ExampleInvestigation on liverworts belonging toRadulaspecies have been reported to
contain aromatic compounds and prenyl bibenzyls (Toyota et al. 1994 ; Asakawa
et al.1991a, b). Recent investigations on liverwortRadula marginata, commonly
found in New Zealand have shown the production of bibenzyl cannabinoids namely
perrottetinene and perrottetinenic acid (Park and Lee 2010 ; Toyota et al. 2002 ).
These compounds have structural similarity with tetrahydrocannabinol (Fig.20.3)
which is the major psychoactive cannabinoid found inC. sativa. Earlier reports
have shown the isolation of perrottetinene from other species likeR. perrottettiand
R. laxiramea(Cullmann and Becker 1999 ; Toyota et al. 1994 ). Interestingly,
bibenzyls are known to have important biological functions like antioxidant,
antibacterial, antifungal and cytotoxic activities (Ludwiczuk and Asakawa 2008 ). It
is highly interesting to note the presence of structurally similar secondary
metabolites in two phylogenetically diverse plants.
Fig. 20.3 Structures of similar cannabinoids inRadula marginata(Perrottetinene) andCannabis
sativa(Tetrahydrocannabinol)
430 P. Kusari et al.