Proteomic analysis of changes in the extracellular matrix of Arabidopsis cell suspension cultures induced by fungal elicitors

Abstract

A proteomic approach has been applied to investigate changes in the extracellular matrix of Arabidopsis thaliana cell suspension cultures following treatments with two fungal pathogen elicitors, chitosan and extracts of Fusarium moniliforme. The oxidative burst and induction of glutathione S-transferase were used as markers for induction of the pathogen defence response. Changes in the cell wall and culture filtrate proteome were profiled. Proteins whose abundance changed reproducibly were analysed via matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry (MS). An increase in the level of two classical cell wall proteins (a putative endochitinase and a polygalacturonase inhibiting protein) and two novel proteins (a putative receptor-like protein kinase and a probable apospory-associated protein) were seen at 24 hours following elicitation. The level of an unknown protein and a hypothetical protein, which has some homology to serine carboxypeptidases, were decreased at 24 hours post-elicitation. In the culture filtrate extracts, we identified two pathogen elicitor responsive proteins, a xyloglucan endo-1,4-beta-D glucanases (XEG) and a peroxidase. Using a combination of two-dimensional polyacrylamide gel electrophoresis, immunoblotting with a phosphotyrosine-specific antibody, and MALDI-TOF MS we discovered that spots that represent putative lectin receptor-like kinase, a putative endochitinase and a XEG possess phosphorylated tyrosine residues. The identification of phosphorylated bona fide cell wall proteins and a putative extracellular receptor-like kinase with no transmembrane domain implicate the existence of an extracellular phosphorylation network which could be involved in intercellular communication.

Characterization of the Complex Locus of Bean Encoding Polygalacturonase-Inhibiting Proteins Reveals Subfunctionalization for Defense against Fungi and Insects

“…In addition to reducing the aggressive potential of PGs, PGIPs favor the formation of long-chain oligogalacturonides (OGs) that are able to induce defense responses . Consistent with their role in defense, PGIPs are ubiquitous in flowering plants and are upregulated in response to stress-related signals, wounding, and fungal and insect attack , and references therein; Li et al, 2003;Ndimba et al, 2003). The overexpression of PGIPs in transgenic plants limits fungal colonization (Powell et al, 2000;Ferrari et al, 2003), thereby demonstrating the defensive potential of these proteins.…”

Identification and profiling of salinity stress-responsive proteins in Sorghum bicolor seedlings

“…After vortexing, the homogenate was centrifuged at 15,700 x g for 10 min and the supernatant containing soluble leaf proteins was collected and stored at -20C. Extracted leaf proteins were quantified using a modified Bradford assay [30] as previously described [31] using BSA as a standard.…”

Identification of an Apoplastic Protein Involved in the Initial Phase of Salt Stress Response in Rice Root by Two-Dimensional Electrophoresis

“…Proteomics is now emerging as a powerful tool for studying these protein dynamics, especially in plant stress responses (Salekdeh et al, 2002;Lee et al, 2004). A number of studies have been performed using proteomic approaches to identify pathogen response proteins in rice and Arabidopsis (Kim et al, 2003;Ndimba et al, 2003) and salt stress response proteins in the rice microsome (Lee et al, 2004), root (Yan et al, 2005), and leaf sheath (Abbasi and Komatsu, 2004). Dani et al (2005) used a proteomic approach to analyze the proteome changes in the tobacco (Nicotiana tabacum) leaf apoplast during longterm (20 d) salt stress.…”