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4.1 Background
Fresh fruits and vegetables are considered essential for health as they provide all
essential dietary supplements. Post-harvest damage prevention of these commodities is a matter of concern as it has lot of economic implications, both at producer
and consumer level. It also affects the availability of raw material and products
based on these items, especially in developing countries. The statistics has revealed
that post-harvest fruit and vegetable damage can reach to very high values, representing over 25% of total production in industrialized countries and over 50% in
developing countries. A variety of biotic agents are responsible for this damage to
fruit and vegetable items. One major damaging group of organisms is fungus. Many
strategies are being followed world over to control these organisms. The control of
fungal phytopathogens is carried out through the application of synthetic fungicides. However, their continuous and consistent use has led to environment problems and are becoming health hazards for humans and animals. As a consequence,
the worldwide trend of consumers to buy agricultural products that come from systems without application of synthetic products has started growing rapidly.
Therefore, global attempts are under way to search for alternatives to control
post-harvest phytopathogenic fungi. Several species of fungi cause post-harvest diseases, including species belonging to Alternaria, Aspergillus, Botrytis, Fusarium,
Geotrichum, Gloeosporium, Mucor, Monilinia, Penicillium, Rhizopus, and other
genera. The control of these phytopathogens is commonly carried out through the
use of synthetic fungicides, but their use is limited due to environmental and toxicological risks. Furthermore, the repeated and continuous use of fungicides has led to
the development of fungus-resistant strains, making the fungicides ineffective
against these strains.
One of the most critical physiological processes during in vivo pathogenesis is
the maintenance of iron homeostasis. The most quarantined fungal pathogen of
stone fruits is Monilinia spp. It has been identified as the brown rot disease of stone
fruits and has developed strains resistant to several of the chemical fungicides.
Therefore, the recent emergence of resistance, the toxicity paradigm, and the limited efficacy of conventional fungicides require the identification of de novo targets
in the metabolism of phytopathogenic fungi.
One alternative can be seen in siderophores. They interfere with the action of
pathogens because they can inhibit enzymes important for their establishment in
post-harvest fruit wounds for survival, virulence, propagation, or resistance to oxidative stress predicted in vivo during infection. Therefore, the biosynthetic pathways of
the fungal siderophores along with their recruitment and utilization mechanisms are
an ideal target for specific pathogens’ resistance-friendly strategy that would block
the proliferation of pathogens without causing any damage to the host.
Iron is the essential component for various life processes (photosynthesis,
enzyme cofactor, redox reagent, respiration, nucleoside, and amino acid synthesis)
of the plant. The symptoms of iron deficiency include loss of photosynthesis, chlorosis, and various harmful processes at the cellular and molecular level.
S. Ashraf et al.
4.1 Background
Fresh fruits and vegetables are considered essential for health as they provide all
essential dietary supplements. Post-harvest damage prevention of these commodities is a matter of concern as it has lot of economic implications, both at producer
and consumer level. It also affects the availability of raw material and products
based on these items, especially in developing countries. The statistics has revealed
that post-harvest fruit and vegetable damage can reach to very high values, representing over 25% of total production in industrialized countries and over 50% in
developing countries. A variety of biotic agents are responsible for this damage to
fruit and vegetable items. One major damaging group of organisms is fungus. Many
strategies are being followed world over to control these organisms. The control of
fungal phytopathogens is carried out through the application of synthetic fungicides. However, their continuous and consistent use has led to environment problems and are becoming health hazards for humans and animals. As a consequence,
the worldwide trend of consumers to buy agricultural products that come from systems without application of synthetic products has started growing rapidly.
Therefore, global attempts are under way to search for alternatives to control
post-harvest phytopathogenic fungi. Several species of fungi cause post-harvest diseases, including species belonging to Alternaria, Aspergillus, Botrytis, Fusarium,
Geotrichum, Gloeosporium, Mucor, Monilinia, Penicillium, Rhizopus, and other
genera. The control of these phytopathogens is commonly carried out through the
use of synthetic fungicides, but their use is limited due to environmental and toxicological risks. Furthermore, the repeated and continuous use of fungicides has led to
the development of fungus-resistant strains, making the fungicides ineffective
against these strains.
One of the most critical physiological processes during in vivo pathogenesis is
the maintenance of iron homeostasis. The most quarantined fungal pathogen of
stone fruits is Monilinia spp. It has been identified as the brown rot disease of stone
fruits and has developed strains resistant to several of the chemical fungicides.
Therefore, the recent emergence of resistance, the toxicity paradigm, and the limited efficacy of conventional fungicides require the identification of de novo targets
in the metabolism of phytopathogenic fungi.
One alternative can be seen in siderophores. They interfere with the action of
pathogens because they can inhibit enzymes important for their establishment in
post-harvest fruit wounds for survival, virulence, propagation, or resistance to oxidative stress predicted in vivo during infection. Therefore, the biosynthetic pathways of
the fungal siderophores along with their recruitment and utilization mechanisms are
an ideal target for specific pathogens’ resistance-friendly strategy that would block
the proliferation of pathogens without causing any damage to the host.
Iron is the essential component for various life processes (photosynthesis,
enzyme cofactor, redox reagent, respiration, nucleoside, and amino acid synthesis)
of the plant. The symptoms of iron deficiency include loss of photosynthesis, chlorosis, and various harmful processes at the cellular and molecular level.
S. Ashraf et al.