© Benaki Phytopathological Institute
Hellenic Plant Protection Journal
10:
51-66, 2017
DOI 10.1515/hppj-2017-0006
Laboratory of General and Agricultural Microbiology
Department of Crop Science, Agricultural University
of Athens, Iera Odos 75, GR 118 55 Votanikos, Athens,
Greece
* Corresponding author:
REVIEW ARTICLE
Endophytic fungi residing in medicinal plants have the ability
to produce the same or similar pharmacologically active
secondary metabolites as their hosts
A. Venieraki, M. Dimou and P. Katinakis*
Summary
Medicinal plants have been used for thousands of years in folk medicines and still are
used for their health benefits. In our days medicinal plants are exploited for the isolation of plant-de-
rived drugs as they are very effective and have relatively less or no side effects. However, the natu-
ral resources of medicinal plants are gradually exhausted and access to plant bioactive compounds
is challenged by the low levels at which these products accumulate in native medicinal plants. For in-
stance, to meet the market demands of 3 Kg per year of vinca alkaloids, powerful plant-derived anti-
cancer drugs, 1.5x10
6
Kg dry leaves are required. In this regard, this review aims to highlight the fact
that endophytic fungi residing in medicinal plants are capable to biosynthesize pharmacologically ac-
tive secondary metabolites similar or identical to those produced by their host medicinal plant. Fur-
thermore, the evolutionary origin of the genes involved in these metabolic pathways as well as the ap-
proaches designed to enhance the production of these metabolites by the isolated endophytic fun-
gi are also discussed.
Additional key words:
metabolites from endophytic bacteria and actinomycetes, chemical ecology
present in virtually all organs of a given plant
host, and some are seed borne. Endophytes
often confer considerable benefits to the
host plant they inhabit, since they can pro-
mote the growth of host plants, enhance re-
sistance to biotic and abiotic stresses (Rodri-
guez
et al
., 2009; Hardoim
et al
., 2015), and
accumulate bioactive secondary metabo-
lites (Kusari
et al
., 2012). The ecological role
of secondary metabolites produced by en-
dophytes is not clear. However, recent stud-
ies have shown that these metabolites are
involved in deterrence of herbivory (Pannac-
cione
et al
., 2014), protection against fungal
(Soliman
et al
., 2015) or bacterial pathogens
(Mousa
et al
., 2017) and amelioration of plant
abiotic stress (Hamayum
et al
., 2016).
Bioactive
secondary
metabolites
derived from medicinal plants are
gradually decreasing - Alternative
approaches
for
their
production
Medicinal plants, as a rich source of nat-
Introduction
Plant endophytes consist of bacterial and
fungal communities that colonize and spend
the whole or part of their life cycle inside
the plant tissues, without instigating any
noticeable symptoms of infection or visible
manifestation of disease to their hosts (Pe-
trini and Fisher, 1990). Evidence of plant-as-
sociated microorganisms found in the fossil-
ized tissues of land plants stems and leaves
suggests that endophyte–plant associa-
tions may have evolved along with the evo-
lution of higher land plants (Krings
et al
.,
2007). Nearly all vascular plant species stud-
ied were found to harbor endophytic bac-
teria and/or fungi (Rodriguez
et al
., 2009;
Hardoim
et al
., 2015). They are found to be
