BIOTIC AND ABIOTIC STRESS
Functional analysis of BADH gene promoter
from Suaeda liaotungensis K.
Yi Zhang Æ Hui Yin Æ Dan Li Æ Weiwei Zhu Æ
Qiuli Li
Received: 26 July 2007 / Revised: 10 September 2007 / Accepted: 19 September 2007 / Published online: 9 October 2007
Ó Springer-Verlag 2007
Abstract A 1,993 bp region upstream of the gene
encoding the betaine aldehyde dehydrogenase (BADH)
was isolated from Suaeda liaotungensis K., and the anal-
ysis of the promoter sequence has revealed the existence of
several putative cis-elements by the PLACE database. In
this study, according to the characteristic of the BADH
promoter, five chimeric constructs varied in the length of
promoter fragments from –1,993, –1,466, –1,084, –573 and
–300 to +62 bp relative to the transcriptional start site were
placed to the upstream of the b-glucuronidase (GUS)
coding region and transferred to Nicotiana tabacum
L.cv.89 by Agrobacterium tumefaciens-mediated leaf-disc
transformation. The functional properties of each promoter
fragment were examined by GUS histochemical staining
and fluorescence quantitative analyses in the transgenic
tobacco leaves treated with different NaCl concentrations
for 48 h. The results show that healthy transgenic plants
had decreased GUS activity in leaves, whereas a higher
GUS activity was observed when the transgenic plants
were challenged with sodium chloride (NaCl). Induction
levels were proportional to the concentration of NaCl
treatment, allowing fine-tuning of protein expression. GUS
enzyme activity was enhanced 6.3-fold in transgenic
tobacco leaves containing –300 bp promoter fragment in
the presence of 400 mmol/l NaCl compared to the nonin-
ductive leaves. This suggests that the smallest promoter
fragment (–300 to +62 bp) possesses all the essential cis-
acting elements and is sufficient for NaCl induction.
Keywords Suaeda liaotungensis K. Á
Betaine aldehyde dehydrogenase Á
BADH promoter deletion analysis Á GUS activity Á
NaCl induction
Abbreviations
BADH Betaine aldehyde dehydrogenase
CaMV Cauliflower mosaic virus
GUS b-Glucuronidase
MUG 4-Methylumbelliferyl-b-
D
-glucuronide
4-MU 4-Methylumbelliferone
X-gluc 5-Bromo-4-chloro-3-indolyl-b-
D
-glucuronide
Introduction
Plants are often exposed to various adverse environmental
stresses such as salinity, drought, heat and cold. Salinity is
one of the major factors that limit the geographical distri-
bution of plants and is responsible for significant reductions
in the yield and quality of many important crops (Boyer
1982). Plants utilize a number of protection mechanisms to
maintain normal cellular metabolism and prevent damage
to cellular components (Wood et al. 1996). One common
metabolic adaptation to salinity stress is the accumulation
of osmoprotectants. One of these osmoprotectants, glycine
betaine, is a quaternary ammonium compound accumulated
in many species of plants in response to salt stress (Hanson
et al. 1991; Rhodes and Hanson 1993; Rathinasabapathi
et al. 2001). Glycine betaine protects the cell from salt
Communicated by J. Register.
Y. Zhang Á H. Yin Á D. Li Á W. Zhu Á Q. Li (&)
College of Life Sciences, Liaoning Normal University,
850 Huanghe Road, Dalian, Liaoning 116029, China
e-mail: liqiuli@dl.cn
Y. Zhang
e-mail: zhangyi_81@126.com
123
Plant Cell Rep (2008) 27:585–592
DOI 10.1007/s00299-007-0459-8