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Isolation and molecular
characterization of a novel homogalacturonan galacturonosyl-
transferase gene (GbGAUT1) from Gossypium
barbadense
J. N. Chi#, G.
Y. Han#, X. F. Wang, G. Y. Zhang, Y. X. Sun and
Z. Y. Ma*
Key Laboratory of Crop Germplasm Resources of Hebei
Province, Agricultural University of Hebei, Baoding, Hebei
071001, People’s Republic of China
*Corresponding author. E-mail:
mzhy@hebau.edu.cn.
Tel.: +86-312- 7528401.
#These authors contributed
equally to this article
Abbreviations: GAUT,
galacturonosyltransferase; RACE,
rapid amplification of cDNA ends; ORF, open reading
frame;
DPA,
day post anthesis, HG, homogalacturonan;
RG- = 1 \* ROMAN I,
rhamnogalacturonan = 1 \* ROMAN
I;
RG- = 2 \* ROMAN II,
rhamnogalacturonan = 2 \* ROMAN II;
GTs, glycosyltransferases; GATL, GAUT-like.
Accepted 8 May, 2009 |
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A novel
gene, designated as GbGAUT1 (Gossypium barbadense
homogalacturonan galacturonosyl-transferase gene 1), was
successfully cloned from G. barbadense (GenBank
accession No. EF552432) by bioinformatics methods, RT-PCR
and RACE. The open reading frame (ORF) was 1797 bp long and
putatively encoded a polypeptide of 598 amino acids, with a
predicted molecular mass of 69 kDa. GbGAUT1 could be
considered as a homogalacturonan (HG)
galacturonosyltransferase protein since the conserved
GAUT1-related supperfamily motif had been found and it was
clustered into GAUT-A group in the phylogenetic tree. Semi
quantitative RT-PCR showed that GbGAUT1
preferentially expressed in the fiber secondary cell wall
thickening, especially in the fibers of 35 day post anthesis
(DPA). These results suggested that the novel cotton
GbGAUT1 might play an important role in fiber
development.
Key
words:
Gossypium barbadense, fiber development, cDNA
cloning, pectin polysaccharide, homogalac-turonan
galacturonosyltransferase. |
