M. guizhouense, and M. pingshaense with plant species from Poaceae and
Asteraceae (Nishi and Sato 2019). Different soil properties, composition of the
microbial community and root exudates may have contributed to inconsistency in
results (Mendes et al. 2013; Wyrebek et al. 2011).
Plant growth promotion associated with endophytic colonization by Metarhizium
spp. has been observed for multiple plant species after endophytic colonization of
various tissues via seed, soil, or foliar inoculation (Ahmad et al. 2020a; Batta 2013;
Behie et al. 2012, 2015; Jaber and Enkerli 2016; Krell et al. 2018; Vega 2018). For
example, three isolates of M. anisopliae significantly enhanced root length and dry
biomass of root and shoot tissues after soil inoculation of 14-day-old tomato
seedlings, although the effect depended on the isolate and inoculation concentration
(Elena et al. 2011). In field experiments, seed inoculation of maize with M. robertsii
and M. anisopliae enhanced leaf collar formation, stand density, stalk length, stalk
and foliage fresh weight, and biomass of stalk, ear, and foliage compared to control
plants (Kabaluk and Ericsson 2007; Liao et al. 2014). Seed inoculation of
M. robertsii enhanced height and above-ground biomass of maize at V4 stage and
the growth promotion effects were correlated with the frequency of detection of the
fungus in plant tissues under greenhouse conditions (Ahmad et al. 2020b). These
results provide evidence that Metarhizium may as a group have a wide host range,
which could facilitate their development and use as plant growth promoters for
agricultural applications.
EIPF in the genus Beauveria endophytically colonized above- and below-ground
plant tissues of various plant species and conferred plant growth promotion and
protection (Bamisile et al. 2018; Hu and Bidochka 2019; Russo et al. 2018; Vega
2018). For example, after foliar application of conidia of Beauveria bassiana to
maize (Zea mays L.), endophytic hyphal growth was observed between epidermal
cells, in the air spaces between parenchymal cells, and in the vascular elements of the
xylem (Wagner and Lewis 2000). B. bassiana was detected in the root as well as
aerial parts of haricot beans (Phaseolus vulgaris) and tomato (Solanum
lycopersicum) (Behie et al. 2015; Russo et al. 2018) suggesting systemic colonization of EIPF in the plant. B. bassiana colonized various tissues of strawberry plants
(Dara and Dara 2015) and improved their growth (Dara 2013). B. bassiana
colonized palm (Phoenix dactylifera) and a proteomic analysis revealed that endophytic colonization induced stress and defense-related proteins, and improved photosynthesis and energy metabolism (Gómez-Vidal et al. 2009). Seed treatment of
broad bean (Vicia faba) with B. bassiana increased plant growth as a result of
systemic colonization (Jaber and Enkerli 2016). After foliar application, endophytic
colonization of maize with B. bassiana resulted in greater plant height, grain weight,
number of leaves, and yield compared with uninoculated control plants (Russo et al.
2019). Foliar application of soybean with B. bassiana resulted in plant growth
promotion under field conditions (Russo et al. 2019). Such growth promotion effects
by endophytic Beauveria suggest that they may be suitable for development as
inoculants to promote growth in crop plants.
Growth promotion effects associated with endophytic colonization by EIPF in
other genera have also been reported. For example, Lecanicillium dimorphum and L.
13 The Role of Endophytic Insect-Pathogenic Fungi in Biotic Stress Management
383
Asteraceae (Nishi and Sato 2019). Different soil properties, composition of the
microbial community and root exudates may have contributed to inconsistency in
results (Mendes et al. 2013; Wyrebek et al. 2011).
Plant growth promotion associated with endophytic colonization by Metarhizium
spp. has been observed for multiple plant species after endophytic colonization of
various tissues via seed, soil, or foliar inoculation (Ahmad et al. 2020a; Batta 2013;
Behie et al. 2012, 2015; Jaber and Enkerli 2016; Krell et al. 2018; Vega 2018). For
example, three isolates of M. anisopliae significantly enhanced root length and dry
biomass of root and shoot tissues after soil inoculation of 14-day-old tomato
seedlings, although the effect depended on the isolate and inoculation concentration
(Elena et al. 2011). In field experiments, seed inoculation of maize with M. robertsii
and M. anisopliae enhanced leaf collar formation, stand density, stalk length, stalk
and foliage fresh weight, and biomass of stalk, ear, and foliage compared to control
plants (Kabaluk and Ericsson 2007; Liao et al. 2014). Seed inoculation of
M. robertsii enhanced height and above-ground biomass of maize at V4 stage and
the growth promotion effects were correlated with the frequency of detection of the
fungus in plant tissues under greenhouse conditions (Ahmad et al. 2020b). These
results provide evidence that Metarhizium may as a group have a wide host range,
which could facilitate their development and use as plant growth promoters for
agricultural applications.
EIPF in the genus Beauveria endophytically colonized above- and below-ground
plant tissues of various plant species and conferred plant growth promotion and
protection (Bamisile et al. 2018; Hu and Bidochka 2019; Russo et al. 2018; Vega
2018). For example, after foliar application of conidia of Beauveria bassiana to
maize (Zea mays L.), endophytic hyphal growth was observed between epidermal
cells, in the air spaces between parenchymal cells, and in the vascular elements of the
xylem (Wagner and Lewis 2000). B. bassiana was detected in the root as well as
aerial parts of haricot beans (Phaseolus vulgaris) and tomato (Solanum
lycopersicum) (Behie et al. 2015; Russo et al. 2018) suggesting systemic colonization of EIPF in the plant. B. bassiana colonized various tissues of strawberry plants
(Dara and Dara 2015) and improved their growth (Dara 2013). B. bassiana
colonized palm (Phoenix dactylifera) and a proteomic analysis revealed that endophytic colonization induced stress and defense-related proteins, and improved photosynthesis and energy metabolism (Gómez-Vidal et al. 2009). Seed treatment of
broad bean (Vicia faba) with B. bassiana increased plant growth as a result of
systemic colonization (Jaber and Enkerli 2016). After foliar application, endophytic
colonization of maize with B. bassiana resulted in greater plant height, grain weight,
number of leaves, and yield compared with uninoculated control plants (Russo et al.
2019). Foliar application of soybean with B. bassiana resulted in plant growth
promotion under field conditions (Russo et al. 2019). Such growth promotion effects
by endophytic Beauveria suggest that they may be suitable for development as
inoculants to promote growth in crop plants.
Growth promotion effects associated with endophytic colonization by EIPF in
other genera have also been reported. For example, Lecanicillium dimorphum and L.
13 The Role of Endophytic Insect-Pathogenic Fungi in Biotic Stress Management
383