Distribution and Expression of Auxin Binding Protein 1 (ABP1) in the Thin Cell Layers of Tobacco

Tobacco （ Nicotiana tabacum L.） pedicel in the blooming period was used to study the distribution of auxin binding protein 1 (ABP1) in the tobacco tissue and cell at different time in the culture of thin cell layers (TCL). Using the immunofluorescence marker it was indicated that the main ABP1 was distributed in the epidermis and the 1st and 2nd layers of the subepidermis cells. A little ABP1 was distributed in the cortex. Tobacco ABP1 was induced to express in the protoplast of tobacco pedicel TCL cultured in MS culture medium containing IAA and BA. Expression of ABP1 in the protoplast was stronger in the active period of vegetative bud differentiation. ABP1 expression became weaker in later period of differentiation. The result of SDS-PAGE and Western blotting showed the molecular weight of tobacco ABP1 in TCL was 26 kD.