Accumulation of 19-kDa plasma membrane polypeptide during induction of freezing tolerance in wheat suspension-cultured cells by abscisic acid.
Suspension-cultured cells derived from immature embryos of winter wheat (Triticum aestivum L. cv. Chihoku) were used in experiments designed to obtain clues to the mechanism of the ABA-induced development of freezing tolerance. Cultured cells treated with 50 microM ABA for 5 d at 23 degrees C acquired the maximum level of freezing tolerance (LT50; -21.6 degrees C). The increased freezing tolerance of ABA-treated cells was closely associated with the remarkable accumulation of 19-kDa polypeptides in the plasma membrane. The 19-kDa polypeptide components were isolated by preparative gel electrophoresis and were further separated into one major (AWPM-19) and other minor polypeptide components by Tricine-SDS-PAGE. N-terminal amino acid sequence of AWPM-19 was determined, and a cDNA clone encoding AWPM-19 was isolated by PCR from the library prepared from the ABA-treated cultured cells. The cDNA clone (WPM-1) encoded a 18.9 kDa hydrophobic polypeptide with four putative membrane spanning domains and with a high pI value (10.2). Expression of WPM-1 mRNA was dramatically induced by 50 microM ABA within a few hours. These results suggest that the AWPM-19 might be closely associated with the ABA-induced increase in freezing tolerance in wheat cultured cells.
Koike
M
M
Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
Takezawa
D
D
Arakawa
K
K
Yoshida
S
S
D000040:Abscisic Acid / Q000494:pharmacology*; D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004591:Electrophoresis, Polyacrylamide Gel; D005615:Freezing; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins; D017386:Sequence Homology, Amino Acid; D014908:Triticum / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D018076:DNA, Complementary; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D010940:Plant Proteins; C107491:WTABAPM protein, Triticum aestivum; D000040:Abscisic Acid