We report localisation of the chickpea bI-Gal, a member of the chickpea b-galactosidase
family, which contains at least four members. After generation of specific antibodies,
the distribution and cellular immunolocalisation of the protein in different
organs and developmental stages of the plant was studied. bI-Gal protein is much
longer than the other chickpea b-galactosidases because of the presence of a lectinlike
domain in the carboxyl terminus of the protein. Western blot experiments indicated
that the active bI-Gal retains this lectin-like domain for its function in the
plant. The bI-Gal protein was mainly detected in cell walls of elongating organs,
such as seedling epicotyls and stem internodes. An immunolocation study indicated
a very good correlation between the presence of this bI-galactosidase and cells
whose walls are thickening, not only in aged epicotyls and mature internodes in the
final phase of elongation, but mostly in cells with a support function, such as collenchyma
cells, xylem and phloem fibres and a layer of sclerenchyma cells surrounding
the vascular cylinder (perivascular fibres). These results could suggest a
function for the bI-Gal in modification of cell wall polymers, leading to thicker
walls than the primary cell walls.
