192
H. B. Slama et al.
(Alvin et al. 2014). ISR activation majorly occurs through the SA-independent
pathway involving jasmonate and ethylene signals (Pettersson and Baath 2004).
They increase the sensitivity to these hormones, to activate several defense genes
(Hase et al. 2003).
8.7 Biological Applications of Endophytic Microorganisms
Nowadays, endophytic microorganisms have been used in multiple fields as biological alternatives to chemical compounds. These microbial populations were involved
in biocontrol of phytopathogens, plant growth stimulation, phytoremediation, bioremediation, medicinal and industrial applications (Strobel and Daisy 2003; Schulz
2006; Jalgaonwala et al. 2011; Godstime et al. 2014; Shukla et al. 2014; Chaudhry
et al. 2017; Uzma et al. 2018).
a. Biological control
Biological control or Biocontrol is the use of microbial antagonists to manage or
inhibit plant pathogens (bacteria, fungi, viruses, and nematodes) (Mehta et al. 2014).
This environment-friendly approach may be an effective solution to get rid of chemical pesticides in the agricultural sector. Therefore, the bioformulation of beneficial
microorganisms could help in enhancing and maintaining plant productivity naturally and cost-effectively (Guédez et al. 2008; Griffin 2014; Nion and Toyota 2015;
Kergunteuil et al. 2016; Alenezi et al. 2017; Høyer et al. 2019).
b. Bioremediation
Bioremediation process implies the use of microbial populations to remove or lessen
pollutants (heavy metals, dye, organic compounds, crude oil, etc.) toxicity from
the biosphere (Kinoshita et al. 2008; Zhou et al. 2014; Limcharoensuk et al. 2015;
Govarthanan et al. 2016; Ijaz et al. 2016; Bharagava et al. 2017; Mefteh et al. 2019).
It is achieved through two major mechanisms: biosorption which is one of the most
convenient techniques of sequestration. It binds contaminants onto the cell walls of
microorganisms (Kousha et al. 2012; Bera et al. 2016; Chew and Ting 2016; Ting
et al. 2016) and bioaccumulation consisting of transporting and precipitating toxic
elements into microbial cells (Kiran et al. 2017) and transforming them into non-toxic
forms (Sathish et al. 2012; Sim et al. 2018, 2019).
c. Phytoremediation
The association of plant-microbes is a perfect combination to solve environmental
pollution/contamination in a maintained, cost-effective, and environment-friendly
manner (Glick 2010; Shin et al. 2012; Chen et al. 2014; Dharni et al. 2014; Ma
et al. 2015; Chirakkara et al. 2016, Rekik et al. 2017; Mefteh et al. 2019). Recently,
heavy metal removal/alleviation by endophytes has been highly studied (Weyens
et al. 2009; Luo et al. 2011; Langella et al. 2014), it is achieved via multiple methods
H. B. Slama et al.
(Alvin et al. 2014). ISR activation majorly occurs through the SA-independent
pathway involving jasmonate and ethylene signals (Pettersson and Baath 2004).
They increase the sensitivity to these hormones, to activate several defense genes
(Hase et al. 2003).
8.7 Biological Applications of Endophytic Microorganisms
Nowadays, endophytic microorganisms have been used in multiple fields as biological alternatives to chemical compounds. These microbial populations were involved
in biocontrol of phytopathogens, plant growth stimulation, phytoremediation, bioremediation, medicinal and industrial applications (Strobel and Daisy 2003; Schulz
2006; Jalgaonwala et al. 2011; Godstime et al. 2014; Shukla et al. 2014; Chaudhry
et al. 2017; Uzma et al. 2018).
a. Biological control
Biological control or Biocontrol is the use of microbial antagonists to manage or
inhibit plant pathogens (bacteria, fungi, viruses, and nematodes) (Mehta et al. 2014).
This environment-friendly approach may be an effective solution to get rid of chemical pesticides in the agricultural sector. Therefore, the bioformulation of beneficial
microorganisms could help in enhancing and maintaining plant productivity naturally and cost-effectively (Guédez et al. 2008; Griffin 2014; Nion and Toyota 2015;
Kergunteuil et al. 2016; Alenezi et al. 2017; Høyer et al. 2019).
b. Bioremediation
Bioremediation process implies the use of microbial populations to remove or lessen
pollutants (heavy metals, dye, organic compounds, crude oil, etc.) toxicity from
the biosphere (Kinoshita et al. 2008; Zhou et al. 2014; Limcharoensuk et al. 2015;
Govarthanan et al. 2016; Ijaz et al. 2016; Bharagava et al. 2017; Mefteh et al. 2019).
It is achieved through two major mechanisms: biosorption which is one of the most
convenient techniques of sequestration. It binds contaminants onto the cell walls of
microorganisms (Kousha et al. 2012; Bera et al. 2016; Chew and Ting 2016; Ting
et al. 2016) and bioaccumulation consisting of transporting and precipitating toxic
elements into microbial cells (Kiran et al. 2017) and transforming them into non-toxic
forms (Sathish et al. 2012; Sim et al. 2018, 2019).
c. Phytoremediation
The association of plant-microbes is a perfect combination to solve environmental
pollution/contamination in a maintained, cost-effective, and environment-friendly
manner (Glick 2010; Shin et al. 2012; Chen et al. 2014; Dharni et al. 2014; Ma
et al. 2015; Chirakkara et al. 2016, Rekik et al. 2017; Mefteh et al. 2019). Recently,
heavy metal removal/alleviation by endophytes has been highly studied (Weyens
et al. 2009; Luo et al. 2011; Langella et al. 2014), it is achieved via multiple methods