Abstract
To elucidate the auxin asymmetry in the gravistimulated cucumber seedlings, we raised polyclonal antibodies of the auxin-carrier-homologs (CS-AUX1; influx carrier, CS-PIN1; efflux carrier) isolated from cucumber and examined the expression and localization of those proteins. The expression of CS-AUX1 protein was observed all around the transition zone, expect for vascular tissue, and more abundantly in the lower side of the transition zone between hypocotyl and root than the peg-suppressed upper side when seeds were germinated in a horizontal position. On the other hand, CS-PIN1 protein accumulated more abundantly in the epidermal and cortical cells of the transition zone of the peg-suppressed upper side than the lower side. CS-PIN1 protein was also detected in the vascular tissue. These results suggest that localized change in the balance of influx and efflux carriers of auxin causes auxin redistribution and subsequently regulates peg formation in cucumber.
