Abstract:
Lipases are known to have important functions in ma
ny physiological processes in
plants. Here, we cloned a lipase gene via Rapid Amp
lification of cDNA Ends
(RACE) technique from
Brassica napus
L., designated as
BnDIL1
(
B. napus
Desiccation-
Induced Lipase 1). The lipase enzyme activity was c
onfirmed by estimating the lipase
activity and reduced lipids content in
Saccharomyces cerevisiae
(pep4)
transformant. Two
B. napus
lines with different oil contents were employed to
examine the transcription
profiles of
BnDIL1
during the processes of seed morphogenesis, maturat
ion, dormancy,
pregermination and germination. The transcription l
evel of lipid degradation pathway
was enhanced during the processes of seed maturatio
n, dormancy, pregermination and
germination, and was higher in seeds of low oil-con
tents line than that of high oil-contents
line. However,
BnDIL1
was significantly activated when seed desiccation
started. Both
“slow desiccation” and “fast desiccation” treatment
s on seedlings dramatically activated
the transcription of
BnDIL1
, while only “slow desiccation” stress, which would
induce the
cell apoptosis, significantly activated the transcr
iption of lipid degradation gene. This
result demonstrated that
BnDIL1
in
B. napus
was desiccation stress dependent gene
rather than fatty acids degradation gene.
Keywords:
Enzyme activity,
Oil-content, Rapid amplification, Seed, Transcripti
on profiles
of
BnDIL1.
