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Biological inoculants interact with rhizospheric microorganisms synergistically and
antagonistically to promote plant growth (Ali and Vidhale 2013; Vejan et al. 2016).
5.4 Siderophore
Siderophores are iron-chelating secondary metabolites of low molecular weight
synthesized by microbes (Sinha et al. 2019), fungi (Renshaw et al. 2002; Manzoor
et al. 2019), graminaceous plants (Garnica et al. 2018), phytoplankton (Reid et al.
1993), cyanobacteria (Arstøl and Hohmann-Marriott 2019), etc. under low- available
iron conditions. Siderophores have binding ability not only with iron but also with
a variety of other metals making them available or excluded from the rhizosphere
offering vigorous growth and enhanced crop productivity and their possible application in phytoremediation studies. Nowadays, siderophores have gained worldwide
importance due to their role as biocontrol, biosensor, bioremediation, and chelating agent.
Siderophore-mediated responses strongly depend on pH and available iron (Jin
et al. 2010). Different siderophores differ in their chemical structures, properties,
and stability constant with iron. Identification of microbial strain on the basis of
siderophore is known as siderotyping. Siderotyping is being used by many workers
for taxonomical identification and characterization of microbes (Bosne and Levy
Frebault 1992; Meyer et al. 2002; Mulet et al. 2008). About 500 different siderophores have been reported so far (Paul and Buttinger 2005). Siderophores are
broadly divided into the catecholate, hydroxamates and carboxylate (Ali and Vidhale
2013). Mostly bacteria and fungi produce hydroxymate siderophore (Balagurunathan
and Radhakrishnan 2007; Ali and Vidhale 2013).
5.5 Benefits of Siderophore
The source of environmental iron is lithosphere in its ore form. Iron is quite copious
on earth. It is ubiquitous and redox active, one of the most essential and crucial element for existence of plant, animal, or microbial life. Iron acts as an essential component in many enzyme-mediated metabolic processes like respiration,
photosynthesis, anabolism of nucleic acids, porphyrin, vitamins, siderophores, and
aromatic compounds (Aguado-Santacruz et al. 2012; Rout 2015). Siderophore
determines the density and structure of rhizospheric microbial biota and enhances
the possibility of obtaining culture of several unculturable microorganisms by making the iron available to them (Saha et al. 2016). In agriculture, siderophore promotes the growth and productivity of crop plants by promoting the iron availability
and uptake, especially in iron-deficient soils. It has been noticed that apart from
iron, siderophores can enhance the availability of other mineral nutrients by
5 Application of Siderophore in Crop Productivity and Remediation of Heavy…
Biological inoculants interact with rhizospheric microorganisms synergistically and
antagonistically to promote plant growth (Ali and Vidhale 2013; Vejan et al. 2016).
5.4 Siderophore
Siderophores are iron-chelating secondary metabolites of low molecular weight
synthesized by microbes (Sinha et al. 2019), fungi (Renshaw et al. 2002; Manzoor
et al. 2019), graminaceous plants (Garnica et al. 2018), phytoplankton (Reid et al.
1993), cyanobacteria (Arstøl and Hohmann-Marriott 2019), etc. under low- available
iron conditions. Siderophores have binding ability not only with iron but also with
a variety of other metals making them available or excluded from the rhizosphere
offering vigorous growth and enhanced crop productivity and their possible application in phytoremediation studies. Nowadays, siderophores have gained worldwide
importance due to their role as biocontrol, biosensor, bioremediation, and chelating agent.
Siderophore-mediated responses strongly depend on pH and available iron (Jin
et al. 2010). Different siderophores differ in their chemical structures, properties,
and stability constant with iron. Identification of microbial strain on the basis of
siderophore is known as siderotyping. Siderotyping is being used by many workers
for taxonomical identification and characterization of microbes (Bosne and Levy
Frebault 1992; Meyer et al. 2002; Mulet et al. 2008). About 500 different siderophores have been reported so far (Paul and Buttinger 2005). Siderophores are
broadly divided into the catecholate, hydroxamates and carboxylate (Ali and Vidhale
2013). Mostly bacteria and fungi produce hydroxymate siderophore (Balagurunathan
and Radhakrishnan 2007; Ali and Vidhale 2013).
5.5 Benefits of Siderophore
The source of environmental iron is lithosphere in its ore form. Iron is quite copious
on earth. It is ubiquitous and redox active, one of the most essential and crucial element for existence of plant, animal, or microbial life. Iron acts as an essential component in many enzyme-mediated metabolic processes like respiration,
photosynthesis, anabolism of nucleic acids, porphyrin, vitamins, siderophores, and
aromatic compounds (Aguado-Santacruz et al. 2012; Rout 2015). Siderophore
determines the density and structure of rhizospheric microbial biota and enhances
the possibility of obtaining culture of several unculturable microorganisms by making the iron available to them (Saha et al. 2016). In agriculture, siderophore promotes the growth and productivity of crop plants by promoting the iron availability
and uptake, especially in iron-deficient soils. It has been noticed that apart from
iron, siderophores can enhance the availability of other mineral nutrients by
5 Application of Siderophore in Crop Productivity and Remediation of Heavy…