Plant Molecular Biology 45: 353–363, 2001.
© 2001 Kluwer Academic Publishers. Printed in the Netherlands.
Molecular cloning and functional characterization of two kinds of
betaine-aldehyde dehydrogenase in betaine-accumulating mangrove
Avicennia marina (Forsk.) Vierh.
, Yu-Ling Meng
, Yoshinobu Kawamitsu
, Yoshito Tanaka
, Hiroshi Ishikawa
, Shigeyuki Baba
, Tetsuko Takabe
, Tadashi Ishii
and Teruhiro Takabe
Faculty of Science & Technology, Meijo University, Tenpaku-ku, Nagoya, Aichi, 468-8502 Japan;
Institute of Meijo University, Tenpaku-ku, Nagoya, Aichi, 468-8502 Japan (
author for correspondence; e-mail:
Facultyof Agriculture, University of the Ryukyus, Okinawa, 903-0213 Japan;
School of Agricultural Science, Nagoya University, Chikusa-ku, Nagoya, Aichi, 464-8601 Japan;
Science, Kanazawa University, Kanazawa, Ishikawa, 920-11 Japan,
Forestry and Products Research Institute,
Tsukuba, Ibaraki, 464-8601 Japan
Received 5 June 2000; accepted in revised form 11 October 2000
Key words: Avicennia marina, betaine, betaine aldehyde dehydrogenase, mangrove, salt tolerance
Glycinebetaine is an important osmoprotectant in bacteria, plants, and animals, but only little information is
available on the synthesis of glycinebetaine in tree plants. Among four mangrove species, glycinebetaine could
be detected only in Avicennia marina. Pinitol was the main osmoprotectant in the other three species. The level of
glycinebetaine in A. marina increased under high salinity. Betaine-aldehyde dehydrogenase (BADH) was detected
in all four species, but choline monooxygenase could not be detected. A cDNA library was constructed from the
leaves of A. marina. Two kinds of BADH cDNAs were isolated, one homologous to the spinach chloroplast BADH,
and the other with unique residues SKL at the end of C-terminus. The BADH transcription levels of the former
were higher than those of the latter. The levels of the former BADH increased at high salinity whereas those of
the latter were independent of salinity. BADHs were expressed in Escherichia coli and puriﬁed. Two kinds of A.
marina BADHs exhibited similar kinetic and stability properties, but were signiﬁcantly different from those of
spinach BADH. A. marina BADHs efﬁciently catalyzed the oxidation of betainealdehyde, but not the oxidation of
ω-aminoaldehydes and were more stable at high temperature than the spinach BADH.
Mangrovesare woodyplantswhichform the dominant
variation in tidal, saline wetlands along tropical and
subtropical coasts. The ecological and sociological
importance of mangroves is well recognized (Tom-
linson, 1986). Mangroves are also physiologically
interesting as potential models for stress tolerance. It is
knownthat the accumulation of low-molecular-weight
The nucleotide sequence data reported will appear in the DDBJ,
EMBL and GenBank Nucleotide Sequence Databases under the
accession numbers AB043539 and AB043540.
organic solutes such as sugars, some amino acids, and
quaternary ammonium compounds are involved in the
Bohnert and Jensen, 1996; Ingram and Bartels, 1996;
Takabe et al., 1998). Glycinebetaine(GB) is an impor-
tant osmoprotectant. GB is a quaternary ammonium
compound present in bacteria, cyanobacteria, algae,
animals, and several plant families (Rhodes and Han-
son, 1993). However, little information was available
on the synthesis of GB in tree plants (Rhodes and
Hanson, 1993), and nothing is known about the GB
synthesis gene in mangroves.