The Location of the Chickpea Cell Wall ßV-Galactosidase Suggests Involvement in the Transition between Cell Proliferation and Cell Elongation

Abstract

We report the generation of antibodies against a ß-galactosidase (ßV-Gal) from Cicer arietinum and the subsequent immunolocalization of the protein in different parts and developmental stages of the plant. ßV-Gal is a cell wall protein encoded by the CanBGal-5 gene, which belongs to a family of at least four ß-galactosidase genes in chickpea. We have previously reported that CanBGal-5 transcripts are located in organs with high elongation and cell division rates, such as meristematic hooks, very young epicotyls, and apical internodes. ßV-Gal protein is the only studied chickpea ß-galactosidase widely present in meristematic hooks, mainly in the meristematic apical zone. These results agree with the previously reported transcription pattern of CanBGal-5 and may reflect its involvement in cell wall modifications during the final stages of cell proliferation, leading to the establishment of an expanding cell wall. The location of ßV-Gal in the cell wall of procambium cells and in pericycle cells of the developing lateral roots also supports the involvement of ßV-Gal in this process. During seedling and plant growth, the highest levels of bV-Gal protein were detected in the youngest actively growing epicotyls and in the apical growing internodes. Thus, protein levels pointed to a relationship between bV-Gal and the events occurring in the cell wall during the early stages of development. Immunolocalization studies in different zones of epicotyls and radicles suggest a role for ßV-Gal in cell elongation.