Reference "Expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid"

Reference ID

8600

Title

Expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid

Source

Plant molecular biology, 1995, vol. 27, pp. 307-315

Authors (4)

Ishitani-M	Nakamura-T
Han-S-Y	Takabe-T

Abstract

When subjected to salt stress or drought, some vascular plants such as barley
respond with an increased accumulation of the osmoprotectant glycine betaine
(betaine), being the last step of betaine synthesis catalyzed by betaine
aldehyde dehydrogenase (BADH). We report here cloning and characterization of
BADH cDNA from barley, a monocot, and the expression pattern of a BADH
transcript. An open reading frame of 1515 bp encoded a protein which showed high
homology to BADH enzymes present in other plants (spinach and sugar-beet) and in
Escherichia coli. Transgenic tobacco plants harboring the clone expressed high
levels of both BADH protein and its enzymatic activity. Northern blot analyses
indicated that BADH mRNA levels increased almost 8-fold and 2-fold,
respectively, in leaves and roots of barley plants grown in high-salt
conditions, and that these levels decreased upon release of the stress, whereas
they did not decrease under continuous salt stress. BADH transcripts also
accumulate in response to water stress or drought, indicating a common response
of the plant to osmotic changes that affect its water status. The addition of
abscisic acid (ABA) to plants during growth also increased the levels of BADH
transcripts dramatically, although the response was delayed when compared to
that found for salt-stressed plants. Removal of plant roots before transferring
the plants to high-salt conditions reduced only slightly the accumulation of
BADH transcripts in the leaves.