Identification of MAMP-Responsive Plasma Membrane-Associated Proteins in Arabidopsis thaliana Following Challenge with Different LPS Chemotypes from Xanthomonas campestris

Abstract

Lipopolysaccharides (LPS) are recognized as microbe-associated molecular patterns (MAMPs) responsible for eliciting defense-related responses and while the effects have been well-documented in mammals, there is a lack of knowledge regarding the mechanism of perception in plant systems and recognized structural moieties within the macromolecular lipoglycan structure. Thus, identification of the LPS plasma membrane (PM) receptor(s)/receptor complex in Arabidopsis thaliana through proteomics will contribute to a deeper understanding of induced defense responses. As such, structurally characterized LPS chemotypes from Xanthomonas campestris pv. campestris (Xcc) wild-type 8004 (prototypical smooth-type LPS) and mutant 8530 (truncated core with no O–chain) strains were utilized to pre-treat A. thaliana plants. The associated proteomic response/changes within the PM were compared over a 24 h period using mass spectrometry-based methodologies following three variants of LPS-immobilized affinity chromatography. This resulted in the identification of proteins from several functional categories, but importantly, those involved in perception and defense. The distinct structural features between wild-type and mutant LPS are likely responsible for the differential changes to the proteome profiles, and many of the significant proteins were identified in response to the wild-type Xcc LPS where it is suggested that the core oligosaccharide and O-chain participate in recognition by receptor-like kinases (RLKs) in a multiprotein complex and, notably, varied from that of the mutant chemotype.

Resistance of Xanthomonas oryzae pv. oryzae to Lytic Phage X2 by Spontaneous Mutation of Lipopolysaccharide Synthesis-Related Glycosyltransferase

“…Glycosyltransferase, which is widely found in bacteria, plays important roles in the etiology of disease and therapeutic targets through catalyzing the formation of glycosidic bond using sugar donors containing a nucleoside phosphate or a lipid phosphate leaving group [ 38 , 39 ]. Glycosyltransferase is involved in the synthesis of LPS, one of the phage adsorption receptors [ 18 ] and pathogen-associated molecular patterns [ 40 , 41 ], which is composed of lipid A, the oligosaccharide core and O-antigen [ 42 ]. The adsorption of phage ΦL7 onto Xanthomonas campestris requires binding to a complex receptor consisting of LPS [ 43 ].…”

CORK1, a LRR-Malectin Receptor Kinase for Cellooligomer Perception in Arabidopsis thaliana

“…Besides CORK1, there are 13 additional LRR-MD-RLKs in Arabidopsis . They have been shown to be involved in lipopolysaccharide perception (Hussan et al, 2020), pollen tube development (Lee and Goring, 2021) and control of cell death in leaves (Li et al, 2020). Several of them are up-regulated by brassinosteroids and participate in immune responses (Qutob et al, 2006; Hok et al, 2014; Xu et al, 2014).…”

The First Line of Defense: Receptor-like Protein Kinase-Mediated Stomatal Immunity

“…Although current data showed that GHR1 is necessary for flg22-triggered stomatal immunity [ 125 ], whether GHR1 functions downstream of FLS2 remains to be clarified. Arabidopsis KINASE 7 (KIN7) was assumed to be a receptor of LPS [ 126 ], that phosphorylates TANDEM PORE K + CHANNEL 1 (TPK1) to regulate ABA- and CO 2 -mediated stomatal closure [ 127 ]. RECEPTOR-LIKE PROTEIN KINASE 1 (RPK1) was supposed to be a positive regulator in ABA signaling.…”