Microbe-Mediated Biotic Stress Signaling
and Resistance Mechanisms in Plants
10
Lebin Thomas and Ishwar Singh
Abstract
Modern agriculture is heavily dependent on agrochemicals for management of
biotic and abiotic stresses faced by crop plants. However, the exclusive dependence on these chemicals has caused an elevated concern about environment,
deleterious effects on non-target organisms, and resistance in target organisms
against synthetic pesticides. Plants respond to numerous biotic and abiotic
stresses by morphological, biochemical, and molecular mechanisms with
interacting signaling pathways involving the membrane-bound or intracellular
receptors that perceive different elicitors such as pathogen-associated molecular
patterns or herbivore-associated molecular patterns (PAMPs/MAMPs/HAMPs)
or effectors, thereby causing a PAMP-triggered immunity (PTI) or pathogens/
insect pest effector-triggered immunity (ETI). One of the recommendations to
overcome the biotic stress concerns includes the development and implementation of biopesticides and biofertilizers, containing the beneficial plant growth
promoting microorganisms (PGPM). These PGPM enhance the growth, yield,
and nutrient uptake of plants, and further, exhibit biological control of plant
diseases. Under natural habitats, the plant–microbe interactions can be crucial
for proper plant nutrient mobilization, growth, development, and protection
against pathogens. Colonization of roots by specific beneficial microbes may
cause induced resistance locally and systemically in plants, which is characterized
by the activation of concealed defense mechanisms that is hormonally regulated
by interconnected signaling pathways. The biotic or abiotic elicitors induce
systemic acquired resistance (SAR) in plant tissues via salicylic acid
(SA) signaling which results in an accumulation of pathogenesis-related proteins
(PR proteins). Whereas, the exposure of roots to PGPM under influence of
L. Thomas · I. Singh (*)
Department of Botany, Hansraj College, University of Delhi, Delhi, India
# The Author(s), under exclusive license to Springer Nature Singapore Pte
Ltd. 2020
B. Giri, M. P. Sharma (eds.), Plant Stress Biology,
https://doi.org/10.1007/978-981-15-9380-2_10
297
and Resistance Mechanisms in Plants
10
Lebin Thomas and Ishwar Singh
Abstract
Modern agriculture is heavily dependent on agrochemicals for management of
biotic and abiotic stresses faced by crop plants. However, the exclusive dependence on these chemicals has caused an elevated concern about environment,
deleterious effects on non-target organisms, and resistance in target organisms
against synthetic pesticides. Plants respond to numerous biotic and abiotic
stresses by morphological, biochemical, and molecular mechanisms with
interacting signaling pathways involving the membrane-bound or intracellular
receptors that perceive different elicitors such as pathogen-associated molecular
patterns or herbivore-associated molecular patterns (PAMPs/MAMPs/HAMPs)
or effectors, thereby causing a PAMP-triggered immunity (PTI) or pathogens/
insect pest effector-triggered immunity (ETI). One of the recommendations to
overcome the biotic stress concerns includes the development and implementation of biopesticides and biofertilizers, containing the beneficial plant growth
promoting microorganisms (PGPM). These PGPM enhance the growth, yield,
and nutrient uptake of plants, and further, exhibit biological control of plant
diseases. Under natural habitats, the plant–microbe interactions can be crucial
for proper plant nutrient mobilization, growth, development, and protection
against pathogens. Colonization of roots by specific beneficial microbes may
cause induced resistance locally and systemically in plants, which is characterized
by the activation of concealed defense mechanisms that is hormonally regulated
by interconnected signaling pathways. The biotic or abiotic elicitors induce
systemic acquired resistance (SAR) in plant tissues via salicylic acid
(SA) signaling which results in an accumulation of pathogenesis-related proteins
(PR proteins). Whereas, the exposure of roots to PGPM under influence of
L. Thomas · I. Singh (*)
Department of Botany, Hansraj College, University of Delhi, Delhi, India
# The Author(s), under exclusive license to Springer Nature Singapore Pte
Ltd. 2020
B. Giri, M. P. Sharma (eds.), Plant Stress Biology,
https://doi.org/10.1007/978-981-15-9380-2_10
297