During the past few decades, several lines of studies have been conducted to
understand rice–M. oryzae interactions in greater detail (Meng et al. 2018b, 2019a).
Moreover, the development of high-throughput omics-based approaches has
facilitated the identification of novel genes, proteins, and metabolites from both
the involved in the plant–pathogen interaction (Gupta et al. 2015b). Results obtained
from these studies have been successfully mapped to the biological pathways
involved in pathogen infection, plant response, and disease progression (Wang
et al. 2017a). Quantitative multi-omics datasets are mapped to known metabolic
networks to identify pathways that are up- or downregulated upon pathogen attack
(Meng et al. 2018a). Alternatively, combined with phenotype data, multi-omics
datasets are used to construct correlation networks during pathogen attack (Gupta
et al. 2018a, 2020).
12.2 PTI Responses in Rice–M. oryzae Interaction
12.2.1 PRRs and PAMPs Identified So Far
As of today, three PAMPs have been identified from the M. oryzae including chitin
(Kuchitsu et al. 1993), MSP1 (Jeong et al. 2007; Wang et al. 2016), and M. oryzae
hypersensitive response-inducing protein 1 (MoHRIP1) (Chen et al. 2012)
(Fig. 12.1). However, the number of identified PRRs from the rice is much higher
as compared to the number of identified PAMPs from M. oryzae. In general, PRRs
include two classes of proteins including receptor-like kinases (RLKs) and receptorlike proteins (RLPs). While RLKs are composed of three domains including an
ectodomain (ECD), a transmembrane domain, and a cytoplasmic kinase domain,
RLPs lack a cytoplasmic kinase domain. Based on the domains or motifs in ECDs,
PRRs are classified into different subfamilies including leucine-rich repeat (LRR)
domain, lysine motifs (LysM), lectin domain, or epidermal growth factor (EGF)-like
domain. LysM-RLPs and LysM-RLKs represent a major class of receptors for the
perception of microbial N-acetyl glucosamine-containing glycans, including fungal
chitin and bacterial peptidoglycan (PGN). The completion of the rice genome
sequencing project has led to the identification of 1131 RLK and 90 RLP genes,
which may be involved in cellular signaling and developmental events. Although,
the genome sequencing project of M. oryzae was also completed almost two decades
ago (Dean et al. 2005), the exact number of PAMPs present could not be predicted
because of the absence of any specific domain or conserved sequence in them.
PAMPs, therefore, can only be identified based on their molecular characterization.
Although several rice PRRs have been predicted, the PRRs that perceive conserved
M. oryzae-derived PAMPs including MSP1, and MoHrip1 could not be identified so
far.
12 Unraveling the Molecular Mechanism of Magnaporthe oryzae Induced. . .
365
understand rice–M. oryzae interactions in greater detail (Meng et al. 2018b, 2019a).
Moreover, the development of high-throughput omics-based approaches has
facilitated the identification of novel genes, proteins, and metabolites from both
the involved in the plant–pathogen interaction (Gupta et al. 2015b). Results obtained
from these studies have been successfully mapped to the biological pathways
involved in pathogen infection, plant response, and disease progression (Wang
et al. 2017a). Quantitative multi-omics datasets are mapped to known metabolic
networks to identify pathways that are up- or downregulated upon pathogen attack
(Meng et al. 2018a). Alternatively, combined with phenotype data, multi-omics
datasets are used to construct correlation networks during pathogen attack (Gupta
et al. 2018a, 2020).
12.2 PTI Responses in Rice–M. oryzae Interaction
12.2.1 PRRs and PAMPs Identified So Far
As of today, three PAMPs have been identified from the M. oryzae including chitin
(Kuchitsu et al. 1993), MSP1 (Jeong et al. 2007; Wang et al. 2016), and M. oryzae
hypersensitive response-inducing protein 1 (MoHRIP1) (Chen et al. 2012)
(Fig. 12.1). However, the number of identified PRRs from the rice is much higher
as compared to the number of identified PAMPs from M. oryzae. In general, PRRs
include two classes of proteins including receptor-like kinases (RLKs) and receptorlike proteins (RLPs). While RLKs are composed of three domains including an
ectodomain (ECD), a transmembrane domain, and a cytoplasmic kinase domain,
RLPs lack a cytoplasmic kinase domain. Based on the domains or motifs in ECDs,
PRRs are classified into different subfamilies including leucine-rich repeat (LRR)
domain, lysine motifs (LysM), lectin domain, or epidermal growth factor (EGF)-like
domain. LysM-RLPs and LysM-RLKs represent a major class of receptors for the
perception of microbial N-acetyl glucosamine-containing glycans, including fungal
chitin and bacterial peptidoglycan (PGN). The completion of the rice genome
sequencing project has led to the identification of 1131 RLK and 90 RLP genes,
which may be involved in cellular signaling and developmental events. Although,
the genome sequencing project of M. oryzae was also completed almost two decades
ago (Dean et al. 2005), the exact number of PAMPs present could not be predicted
because of the absence of any specific domain or conserved sequence in them.
PAMPs, therefore, can only be identified based on their molecular characterization.
Although several rice PRRs have been predicted, the PRRs that perceive conserved
M. oryzae-derived PAMPs including MSP1, and MoHrip1 could not be identified so
far.
12 Unraveling the Molecular Mechanism of Magnaporthe oryzae Induced. . .
365