Authors: D J Sherrier G S Taylor K A T Silverstein M B Gonzales K A VandenBosch
Publish Date: 2005/05/04
Volume: 225, Issue: 1-2, Pages: 43-55
Abstract
Nodulins encoding repetitive prolinerich cell wall proteins PRPs are induced during early interactions with rhizobia suggesting a massive restructuring of the plant extracellular matrix during infection and nodulation However the proteins corresponding to these gene products have not been isolated or characterized nor have cell wall localizations been confirmed Posttranslational modifications conformation and interactions with other wall polymers are difficult to predict on the basis of only the deduced amino acid sequence of PRPs PsENOD2 is expressed in nodule parenchyma tissue during nodule organogenesis and encodes a protein with distinctive PRP motifs that are rich in glutamate and basic amino acids A database search for the ENOD2 signature motifs indicates that similar proteins may have a limited phylogenetic distribution as they are presently only known from legumes To determine the ultrastructural location of the proteins antibodies were raised against unique motifs from the predicted ENOD2 sequence The antibodies recognized nodulespecific proteins in pea Pisum sativum with a major band detected at 110 kDa representing a subset of PRPs from nodules The protein was detected specifically in organelles of the secretory pathway and intercellular spaces in the nodule parenchyma but it was not abundant in primary walls Similar proteins with an analogous distribution were detected in soybean Glycine max The use of polyclonal antibodies raised against signature motifs of extracellular matrix proteins thus appears to be an effective strategy to identify and isolate specific structural proteins for functional analysis
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