Effects of Endocrine Disruptor Di-n-butyl
phthalate on Bok choy
(Brassica
rapa
subsp. chinensis)
Chien-Sen Liao, Jui-Hung Yen,
and Yei-Shung Wang *
D
epartment of Agricultural Chemistry, National Taiwan University,
Taipei, Taiwan
Abstract
Di-n-butyl
phthalate (DBP) is one of the phthalate
esters (PAEs)
and
endocrine disruptor. In this research,
we investigated the effects of DBP
on leaf vegetable. White stem bok
choy (Brassica rapa
subsp. chinensis),
one of the most popular leaf
vegetable
in Taiwan was chose in this study. The
results showed that leaves of bok choy became white, chlorosis and necrosis as
30 mg L-1
DBP treated
after 42 days. Transmission electron microscopic
image of white
leaves revealed changes in the chloroplast structures. Biomass
and chlorophyll concentration of bok choy
decreased as exposure in DBP treatment. However, DBP
accumulation in bok choy increased with dose of DBP in
hydroponic
system.
The
growth and morphology of
bok choy
showed a significant dose-response relationship with
DBP
dosage.
Furthermore, the leaf tissue of bok choy was collected for proteome-level analysis using
two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). We
identified 6 protein spots that showed reproducible differences in expression
between the normal and the DBP-treated bok choy. The
protein level studies revealed the increased expression of superoxide dismutase
(SOD) and peroxidase 21 precursor, which both responsible
of
the detoxification of
free radical in all cells. However, heat shock cognate protein 80, protein disulfide isomerase
precursor, apocytochrome f precursor and
RNA polymerase beta subunit were all decreased
as DBP
treated. They were
take charge of polypeptide folding, electron transport chain and
DNA transcription in cells. In addition to these
results indicated that DBP affects the
proteome and physiology
as well as the morphology of bok choy. Four decreased proteins might relate to
the growth and development of bok choy.
Keywords:
Endocrine disruptors;
Di-n-butyl phthalate;
bok choy;
morphology; proteome