Genotyping-by-sequencing-based identification ofArabidopsispattern recognition receptor RLP32 recognizing proteobacterial translation initiation factor IF1

Abstract

Pattern-triggered immunity (PTI) is a central component of plant immunity. Activation of PTI relies on the recognition of microbe-derived structures, termed patterns, through plant encoded surface-resident pattern recognition receptors (PRRs). We have identified proteobacterial translation initiation factor 1 (IF1) as an immunogenic pattern that triggers PTI in Arabidopsis thaliana and some related Brassicaceae species. Unlike most other immunogenic patterns identified, IF1 elicitor activity cannot be assigned to a small peptide epitope, suggesting that tertiary fold features are required for IF1 receptor activation. We have deployed natural variation in IF1 sensitivity to identify leucine-rich repeat (LRR) receptor-like protein 32 (RLP32) as the corresponding Arabidopsis receptor using a restriction site-associated DNA sequencing (RAD-seq) approach. Transgenic expression of RLP32 confers IF1 sensitivity to rlp32 mutants, IF1-insensitive Arabidopsis accessions and IF1-insensitive Nicotiana benthamiana. RLP32 binds IF1 specifically and forms complexes with LRR receptor kinases SOBIR1 and BAK1 to mediate signaling. Similar to previously identified PRRs RLP32 confers resistance to Pseudomonas syringae infection, highlighting an unexpectedly complex array of bacterial pattern sensors within a single plant species.

The EDS1–PAD4–ADR1 node mediates Arabidopsis pattern-triggered immunity

“…and IF1 (which is recognized by RLP32) 12 triggered a reduced ethylene response in a pbl30 mutant, although in some cases, differences were not statistically significant; responses in the pbl32 mutant were not impaired to any elicitor (Extended Data Fig. 1).…”

Cell-Wall-Degrading Enzymes-Related Genes Originating from Rhizoctonia solani Increase Sugar Beet Root Damage in the Presence of Leuconostoc mesenteroides

“…Further analysis of candidate genes belonging to the highly co-expressed gene modules is needed, such as those of ME_turquoise, which includes NH16_RS05440 (ADP-ribose pyrophosphatase), NH16_RS06070 (prolyl-dipeptidyl aminopeptidase), NH16_RS03690 (glycosyl transferase), msrA (protein repair), and mgtE (magnesium transporter), etc. Many of these genes mentioned above have been demonstrated to be important bacterial pathogenicity-related factors and could serve as potential targets for future mitigation strategies [36][37][38]. Besides the genes mentioned above, the high abundance of specific L. mesenteroides rRNA genes indicate the role of these genes during early bacterial pathogenesis [39] when rapid multiplication is one of the key events.…”

Multi-omics approach highlights differences between RLP classes in Arabidopsis thaliana

“…The currently unidentified SCLEROTINIA CUL-TURE FILTRATE ELICITOR 1 (SCFE1) is perceived via RLP30 [27]. RLP32 recognizes the structural fold of the bacterial translation initiation factor − 1 (Inf-1) present in all proteobacteria [31] and RLP42/RBPG1 detects several endopolygalacturonases from Botrytis cinerea and Aspergillus niger [28]. Finally, RLP3 is the causal gene of the quantitative resistance locus RFO2 in Arabidopsis conferring resistance against the vascular wilt fungus Fusarium oxysporum forma specialis matthioli [29].…”

“…The VDRs RLP1, RLP23, RLP30, RLP32 and RLP42 all require BRASSINOSTEROID-INSENSITIVE KINASE 1 (BAK1) and SUPPRESSOR OF BIR1 (SOBIR1) for full function. The aforementioned RLPs are constitutively associated with SOBIR1 at the plant plasma membrane, then upon ligand perception BAK1 is recruited to the complex [23,25,27,28,31]. The interaction with SOBIR1 is mediated via a stretch of negatively charged amino acids, Aspartate (D) and Glutamate (E), in the extracellular juxtamembrane region, just before the transmembrane domain and a conserved GxxxG motif within the transmembrane region [30].…”