Specificity in the immobilisation of cell wall proteins in response to different elicitor molecules in suspension-cultured cells of French bean (Phaseolus vulgaris L.)

Abstract

A characteristic of the defence response is the immobilisation of wall proteins possibly through the formation of covalent cross-links and the subsequent barrier formation against pathogens. A requirement for this is the generation of active oxygen species, particularly hydrogen peroxide. In the present work, we examine in depth the requirement for H2O2 and the specificity of the immobilisation with respect to particular wall proteins. Salt-extractable wall proteins were analysed for hydroxyproline content and the subset of proteins with this post-translational modification was found to be small. About 50 proteins were found to be easily salt-extractable and in response to elicitor treatment about 5 were found to be specifically immobilised. Immobilisation was very rapid and completed within 15 min after elicitation, and dependent upon the type of elicitor and the intensity of the production of active oxygen species. N-terminal sequencing and amino acid analysis revealed that, apart from one polypeptide, all immobilised proteins were (hydroxy)proline-containing glycoproteins with O-linked oligosaccharide side chains. In contrast, N-linked glycoproteins were not immobilised. N-terminal protein sequencing revealed the immobilised HRGPs to be novel, but both extensin and PRP-like. Implications of these findings for both pathogenic and symbiotic processes are also discussed.

A Peroxidase-Dependent Apoplastic Oxidative Burst in Cultured Arabidopsis Cells Functions in MAMP-Elicited Defense

“…These data together with our proteomic data suggest a sensing mechanism that monitors the integrity of the cell wall. Consistent with this model, previous studies in French bean cell cultures and legumes have shown that Fusarium cell wall elicitor causes peroxidative cross-linking and immobilization of Pro-and Cys-rich polypeptides within the wall (Bradley et al, 1992;Wojtaszek et al, 1995;Wojtaszek, 1997;Bindschedler et al, 2006). Also consistent with this model is the finding that leaves of ecotype Columbia plants expressing asFBP1 are about 30% larger than wild-type leaves Daudi et al, 2012).…”

“…Pectinacetylesterases and pectinmethylesterases control the degree of acetyl and methyl esterification of cell wall polygalacturonans, and PGIPs inhibit cell expansion by inhibiting the cell wall-loosening activity of polygalacturonases that hydrolyze pectin. Although significant changes in the cross-linking of Hyp-rich glycoproteins following elicitor treatment have not been observed (Brisson et al, 1994;Wojtaszek et al, 1995;Brown et al, 1998), it is possible that the knockdown of basal levels of PRX33 and PRX34 leads to cell expansion by diminishing peroxidase-catalyzed crosslinking of cell wall polymers, which in turn affects the regulation of genes involved in cell expansion. A similar compensatory mechanism has also been observed in mutants lacking the cellulose synthase gene CESA3, where a reduction of cellulose content affected the pectin and xyloglucan composition of the cell wall (Cañ o-Delgado et al, 2003;Bosca et al, 2006).…”

“…Proteins were extracted from the cell walls of intact cells by the CaCl 2 method and processed for SDS-PAGE as described previously (Wojtaszek et al, 1995). Selected bands from SDS-PAGE gels were excised, cut into 1-mm 2 pieces, and placed in nonstick Eppendorf tubes.…”

Deciphering the Responses of Root Border-Like Cells of Arabidopsis and Flax to Pathogen-Derived Elicitors

“…The recognition of MAMPs through specific plant receptors triggers the activation of a collaborative defense response to restrict pathogen growth. This primary innate immune response includes the induction of mitogen-activated protein kinase signaling, transcriptional reprogramming, production of reactive oxygen species (ROS; Boller and Felix, 2009;Millet et al, 2010), and modifications of cell wall structure via deposition of callose (Hao et al, 2008) or accumulation of Hyp-rich glycoproteins such as extensin (Wojtaszek et al, 1995;Ribeiro et al, 2006). Most of this knowledge has come from a number of studies performed on leaves.…”

Localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells to Pseudomonas syringae pv phaseolicola.

“…Some of these features have been associated with developmental and pathological cell death in plants (Mittler and Lam, 1995; Levine et al, 1996; Ryerson and Heath, 1996;Wang et al, 1996), but the HR often lacks the classic ultrastructural features associated with apoptosis (Bestwick et al, 1995; Mittler and Lam, 1996). AOS have been shown to induce apoptosis in mammalian cells, but the involvement of AOS in the execution of apoptotic cell death is controversial (Buttke and Sandstrom, 1995; Jacobson, 1996).In plants, H,Op production is also involved in the defensive modifications that occur within the walls of challenged cells (Bolwell, 1993;Wojtaszek et al, 1995). In some cases, alteration to cell wall structure may be an extremely rapid response.…”