The expression of a newCicer arietinum cDNA, encoding a glutamic acid-rich protein, is related to development

The cDNA named Cap28 was isolated from an epicotyl cDNA library of Cicer arietinum stressed seedlings as a clone whose transcript abundance decreased under the PEG-induced water stress. Since under this condition epicotyl growth was inhibited, the involvement of the corresponding gene in the growth process was studied. One feature of its encoded protein was the presence of a high percentage of three amino acids, Glu, Pro and Ala, the first one appearing in pairs. The expression pattern of the Cap28 corresponding gene suggests that it is associated with developing organs undergoing cell division and cell elongation and that it may be involved in one of these processes. Thus, the highest Cap28 expression was found in young epicotyls and decreased in older ones. Cap28 expression was induced by auxins and brassinolides, suggesting that these hormones could mediate the processes in which the Cap28-encoded protein is involved. Moreover, Cap28 seems to be developmentally regulated in view of its higher expression in tissues whose cells undergo division processes, such as meristematic hooks and apical internodes. High expression was also detected in early stages of seed development.