© 1995 Heron Publishing—Victoria, Canada
Characterization of BspA, a major boiling-stable, water-stress-responsive protein in aspen (Populus tremula)
Dan Pelah (1), Oded Shoseyov (1, 2) and Arie Altman (1, 2, 3)
1. The Kennedy Leigh Center for Horticultural Research, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel / 2. The Otto Warburg Center for Agricultural Biotechnology, Faculty of Agriculture, The Hebrew University of Jerusalem, P.O. Box
12, Rehovot 76100, Israel / 3. Author to whom correspondence should be addressed / Received August 12, 1994
Summary
We identified a novel 66 kDa boiling-stable protein (BspA) in cultured shoots of aspen (Populus tremula L.) which was highly expressed in response to gradual water stress. The BspA protein, which was highly expressed as early
as 1 h after initiation of a drought treatment, accumulated during progressive water stress, decreased on rehydration, and
was expressed in response to abscisic acid (ABA) application, as detected by SDS-PAGE protein analysis and Western blotting.
Anti-BspA antibodies also cross-reacted with a 119 kDa protein. The 119 kDa protein was also induced by water stress, but
it was detected only in the total protein fraction and not in the heat-stable fraction. The BspA protein cross-reacted with
antibodies raised against a water-stress-responsive protein isolated from the African resurrection plant Craterostigma plantagineum Hochst. The N-terminal amino acid sequence of BspA was determined and exhibited high homology with the wheat germins GF-2.8
and GF-3.8. The BspA protein was the only major, water-stress-responsive boiling-stable protein detected in aspen.
Keywords:
ABA, boiling-stable protein, drought, water stress.
