A simple method for in situ hybridization to RNA in guard cells of Vicia faba L.:: The expression of aquaporins in guard cells

Because the epidermis of V. faba L. leaves easily can be peeled into strips of one cell layer, we developed a simple method of in situ hybridization using epidermal peels as a substitute for paraffin, resin and cryosections. Our method sufficiently detected the expression of broad bean aquaporin 1 in guard cells. RT-PCR revealed higher expression of aquaporins (AQPs) in guard cells compared to other leaf cell types; this indicates the importance of AQP for bulk water flow across guard cell membranes and, therefore, for stomatal movements.