Chitin-induced systemic disease resistance in rice requires both OsCERK1 and OsCEBiP and is mediated via perturbation of cell-wall biogenesis in leaves

Abstract

Chitin is a well-known elicitor of disease resistance and its recognition by plants is crucial to perceive fungal infections. Chitin can induce both a local immune response and a systemic disease resistance when provided as a supplement in soils. Unlike local immune responses, it is poorly explored how chitin-induced systemic disease resistance is developed. In this study, we report the systemic induction of disease resistance against the fungal pathogen Bipolaris oryzae by chitin supplementation of soils in rice. The transcriptome analysis uncovered genes related to cell-wall biogenesis, cytokinin signaling, regulation of phosphorylation, and defence priming in the development of chitin-induced systemic response. Alterations of cell-wall composition were observed in leaves of rice plants grown in chitin-supplemented soils, and the disease resistance against B. oryzae was increased in rice leaves treated with a cellulose biosynthesis inhibitor. The disruption of genes for lysin motif (LysM)-containing chitin receptors, OsCERK1 (Chitin elicitor receptor kinase 1) and OsCEBiP (Chitin elicitor-binding protein), compromised chitin-induced systemic disease resistance against B. oryzae and differential expression of chitin-induced genes found in wild-type rice plants. These findings suggest that chitin-induced systemic disease resistance in rice is caused by a perturbation of cell-wall biogenesis in leaves through long-distance signalling after local recognition of chitins by OsCERK1 and OsCEBiP.

Induced systemic resistance by the root colonization ofTrichoderma atrovirideis independent from the chitin-mediated signaling pathway in Arabidopsis

“…Since the treatments of heat-killed L. bicolor and chitin also systemically induced disease resistance, the authors proposed that ISR without symbiotic association would be triggered by the root perception of PAMPs/MAMPs, which is supported by our previous study (Takagi et al, 2022). In rice, supplementing soils with chitin systemically induced disease resistance against the necrotrophic pathogen Bipolaris oryzae through the function of LysM-type PRRs, OsCERK1, and OsCEBiP.…”

“…Chitin is a PAMP/MAMP used by plants to sense the presence of fungi in intracellular spaces (Shu et al, 2023). Like beneficial fungus colonization, applying chitin into soils promotes plant growth and induces systemic resistance (Parada et al, 2018;Kaminaka et al, 2020;Takagi et al, 2022).…”

“…Additionally, soil application of chitin improves plant growth in various crops, which is thought to be independent of induced disease resistance. We have recently reported that supplementing soils with chitin systemically induces disease resistance against necrotrophic fungal pathogens in Arabidopsis, cabbage, strawberry, and rice (Parada et al ., 2018; Takagi et al ., 2022). Thus, chitin application to soils and beneficial root endophytic fungi induce similar systemic responses in plants, growth promotion and disease resistance.…”

Dipicolinic acid enhances kiwifruit resistance to Botrytis cinerea by promoting phenolics accumulation

“…59 CERK1 orthologs have been detected in Arabidopsis and rice, wherein they play a key role in the activation of immune responses. 60 The observed up-regulation of CERK1 suggests that DPA is stimulating a defense response in kiwifruit. PRs play an essential role in defense signaling and have been considered marker genes for immunity response.…”

“…Activation of CERK1 involves the accumulation of ROS and pathogenesis‐related proteins (PRs) 59 . CERK1 orthologs have been detected in Arabidopsis and rice, wherein they play a key role in the activation of immune responses 60 . The observed up‐regulation of CERK1 suggests that DPA is stimulating a defense response in kiwifruit.…”