Concanavalin a as a Probe for the Epidermis- Specific Secretion of Glycoproteins during Iaa- Induced Growth in Rye Coleofitlib

Auxin(IAA)-induced extension growth of primary plant cell walls is regulated via cell wall loosening the molecular mechanism of which is unresolved. In electronmicroscopical studies it has been demonstrated that IAA-induced growth in grass coleoptiles is cbc ter ized by the IAA-induced occurrence of osmiophilic particles (OPs) specifically in the outer periplasmic space of the tension-stressed load-bearing epidermis. Although their physiological significance is not yet identified, O h fulfill several criteria to be. expected from wall loosening factors. According to recent reports O h appear to consist of or to contain glycoproteirs (Edelmann et al.). In the present study ConA a lectin specifically binding to man and glc has been employed to further characterize OPs and to analyze its effect on growth. For this, abraded coleoptile segme ts of 3 d old dark grown rye