248
C. García-Latorre et al.
et al. 2015). Initially, it was presumed that endophytic fungi only colonized aboveground plant tissues (leaves, stems, bark, petioles, and reproductive structures), which
distinguished them from mycorrhizal fungi. Later, numerous studies nowadays have
demonstrated that fungal endophytes may also inhabit root tissues (Huang et al. 2019;
Li et al. 2019; Strom et al. 2019; Yamaji et al. 2016). Overall, endophytic fungi are
ubiquitous and extremely diverse in host plants; in fact, every plant examined with
this purpose has been found to harbor at least one species of endophytic fungus
(Arnold et al. 2000; Saikkonen et al. 2000). Furthermore, it is interesting to note that
such a high diversity, i.e. more than 100 different species can be found in a single
plant species (Sánchez et al. 2012).
Researches on fungal endophytes have increased in recent years and an increasing
number of studies exhibited the beneficial effects of diverse endophyte species on
their plant hosts. Several endophytes have been shown to confer resistance to plants
against herbivores and phytopathogens (Clay and Schardl, 2002; Rodrigo et al. 2017;
Romeralo et al. 2015), to improve the nutritional status of the plant host (Lledó et al.
2016), and its competitiveness toward other plant species (Vázquez de Aldana et al.
2013), to increase its photosynthetic efficiency (Spiering et al. 2006), antioxidant
capacity (Hamilton and Bauerle 2012) and increase plant adaptation to stressful habitats such as of drought (Giauque and Hawkes 2013), salinity (Redman et al. 2011),
and heavy metals (Zamani et al. 2015). These studies provide pieces of evidence
regarding the important role played by endophytes in the adaptation and survival of
plants even under stressful habitats and conditions.
The endophytes have been identified as an important source of novel and diverse
active secondary metabolites of great scientific and industrial interest (Brader et al.
2014; Dheeman et al. 2017; Schulz et al. 2002; Surup et al. 2018). These active
metabolites, often involved in the beneficial effects observed in plant hosts, might
confer their adaptation capacity toward stressful conditions, and their resistance in
adverse field conditions. For instance, metabolites produced by Penicillium citrinum
Thom isolated from Ixeris repens (L.) A.Gray, when applied in Carex kobomugi
Ohwi showed better growth, higher chlorophyll and carotenoids content, as well as
higher efficiency in carboxylation and the water use (Hwang et al. 2011).
11.2 Enhancing Plant Nutrient Uptake
In the last decades of the twentieth century, the importance of soil as a basic environmental component has been highlighted, recognizing that soil is a nonrenewable
resource that virtually needs time for its regeneration or nutrients replacement (Nortcliff 2002). Sustainable soil management practices are essential for maintaining
proper soil health for the future production of crops. However, the intensification
of the cropping systems, which is causing salinization in many soils especially in
arid and semi-arid regions (Khan et al. 2005), and climate change (reducing the
amount of available water for crops) are contributing to the soil quality deterioration
and decreasing the availability of the nutrients for plants. Under this scenario, the
C. García-Latorre et al.
et al. 2015). Initially, it was presumed that endophytic fungi only colonized aboveground plant tissues (leaves, stems, bark, petioles, and reproductive structures), which
distinguished them from mycorrhizal fungi. Later, numerous studies nowadays have
demonstrated that fungal endophytes may also inhabit root tissues (Huang et al. 2019;
Li et al. 2019; Strom et al. 2019; Yamaji et al. 2016). Overall, endophytic fungi are
ubiquitous and extremely diverse in host plants; in fact, every plant examined with
this purpose has been found to harbor at least one species of endophytic fungus
(Arnold et al. 2000; Saikkonen et al. 2000). Furthermore, it is interesting to note that
such a high diversity, i.e. more than 100 different species can be found in a single
plant species (Sánchez et al. 2012).
Researches on fungal endophytes have increased in recent years and an increasing
number of studies exhibited the beneficial effects of diverse endophyte species on
their plant hosts. Several endophytes have been shown to confer resistance to plants
against herbivores and phytopathogens (Clay and Schardl, 2002; Rodrigo et al. 2017;
Romeralo et al. 2015), to improve the nutritional status of the plant host (Lledó et al.
2016), and its competitiveness toward other plant species (Vázquez de Aldana et al.
2013), to increase its photosynthetic efficiency (Spiering et al. 2006), antioxidant
capacity (Hamilton and Bauerle 2012) and increase plant adaptation to stressful habitats such as of drought (Giauque and Hawkes 2013), salinity (Redman et al. 2011),
and heavy metals (Zamani et al. 2015). These studies provide pieces of evidence
regarding the important role played by endophytes in the adaptation and survival of
plants even under stressful habitats and conditions.
The endophytes have been identified as an important source of novel and diverse
active secondary metabolites of great scientific and industrial interest (Brader et al.
2014; Dheeman et al. 2017; Schulz et al. 2002; Surup et al. 2018). These active
metabolites, often involved in the beneficial effects observed in plant hosts, might
confer their adaptation capacity toward stressful conditions, and their resistance in
adverse field conditions. For instance, metabolites produced by Penicillium citrinum
Thom isolated from Ixeris repens (L.) A.Gray, when applied in Carex kobomugi
Ohwi showed better growth, higher chlorophyll and carotenoids content, as well as
higher efficiency in carboxylation and the water use (Hwang et al. 2011).
11.2 Enhancing Plant Nutrient Uptake
In the last decades of the twentieth century, the importance of soil as a basic environmental component has been highlighted, recognizing that soil is a nonrenewable
resource that virtually needs time for its regeneration or nutrients replacement (Nortcliff 2002). Sustainable soil management practices are essential for maintaining
proper soil health for the future production of crops. However, the intensification
of the cropping systems, which is causing salinization in many soils especially in
arid and semi-arid regions (Khan et al. 2005), and climate change (reducing the
amount of available water for crops) are contributing to the soil quality deterioration
and decreasing the availability of the nutrients for plants. Under this scenario, the