A seedling specific vegetative lectin gene is related to development in Cicer arietinum

Abstract

Plant lectins are a group of glycoproteins with the ability to recognize and bind carbohydrate ligands. Seed lectins function as storage and defense proteins, but the specific function of vegetative lectins is uncertain. In this paper we describe the characterization of a clone, CanVLEC, encoding a vegetative lectin from chickpea (Cicer arietinum L. cv. Castellana). The expression of the CanVLEC gene was specific in seedlings, mostly in hooks and elongating epicotyls, and no expression was detected in adult plants. The level of chickpea vegetative lectin transcripts in epicotyls decreased through the epicotyl growth suggesting a relationship to development. Treatment with indoleacetic acid (IAA) and brassinolides (BR), hormones that promoted elongation in chickpea epicotyl, increased the level of CanVLEC mRNA, supporting a relationship to growth. CanVLEC is drastically down regulated by water deficit ruling out its possible involvement in plant response to water stress, unlike other vegetative lectins. CanVLEC protein may be targeted to an extracellular location owing to the presence of a signal peptide.