TITLE:
Cloning and Enzymatic Activity Analysis of the Malonyl-CoA:acyl Carrier Protein Transacylase in Brassica napus Cultivars with Different Oil Content
AUTHORS:
Chenning Qu, Huanhuan Jiang, Lei Zhang
KEYWORDS:
Malonyl-CoA:acyl Carrier Protein Transacylase (MCAT), Brassica Napus, Oil Content, Relative Activities
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.18,
August
7,
2014
ABSTRACT: The full-length genomic DNA of MCAT (Malonyl-CoA:acyl carrier protein transacylase) in Brassica napus was cloned. BnMCAT shares very high identity with AtMCAT in gene sequence and gene structure. A multiple alignment of the protein
sequence showed that BnMCAT shares
high identity with other MCATs from E.
coli and plants. BnMCAT was
expressed in all tissues, such as roots, stems, leaves, flowers, and seeds, and
no significant differences in the expression level were found in different
embryo stages after pollination. According to an in vitro relative activity analysis, purified recombinant BnMCAT expressed in E. coli had transacylase activity. Although the relative activities
of BnMCAT in crude extracts isolated
from different staged embryos were similar and showed little variation, a
higher relative activity was found in a crude extract isolated from embryos in
comparison to leaves. Different relative activities of BnMCAT in crude extracts isolated from cultivars with different oil
content were also found, suggesting that the activity of BnMCAT might be a decisive factor for a high oil content. Together,
these results showed that BnMCAT is
an important enzyme in the FAS system and indicate that BnMCAT might be a new target enzyme for future crop improvement
through genetic engineering.