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Isolation and expression
pattern of COR15b and KIN1 genes in watermelon
and pumpkin
Kang Guozhang1,2*,
Zhu Zhonghou2, Guo Tiancai1 and Ren
Jiangping1
1Henan
Agricultural University; Zhengzhou 450002, China.
2Henan
Provincial Engineering Research Center for Watermelon
Breeding, Luoyang 450002, China.
*Corresponding author. E-mail:
zkangg@163.com.
Accepted 9 October, 2009 |
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COR15b
and KIN1 (COR 6.5) genes encode polypeptides of 15
KDa and 6.5 KDa, respectively. They are involved in the
dehydration tolerance mechanisms and play important role
under cold stress. cDNA sequences of COR15b and
KIN1 genes were firstly isolated from leaves of watermelon
(Citrullus lanatus) and pumpkin (Cucurbita
moschata). Sequencing results indicated that the open
reading fragments (ORF) of COR15b in watermelon (ClCOR15b)
and COR15b in pumpkin (CmCOR15b) were 348 and
426 bp, which encoded 116 and 141 amino acids, respectively.
The putative amino acids of CmCOR15 b shared 98.58%
identities to COR15b in Arabidopsis (AtCOR15b),
but ClCOR15b had only 80.85% identities to
AtCOR15b because there appeared two mutations at the
positions of 220 (C/T) and 418 (T/A) in ClCOR15b and
T/A mutation produced a transcript end codon (TAA), which
led to a lack of 26 amino acids. Similar with KIN1 in
Arabidopsis (AtKIN1), ORFs of both KIN1 in
watermelon (ClKIN1) and KIN1 in pumpkin
(CmKIN1) were 198 bp, encoding two short polypeptides
of 65 amino acids. The putative amino acids of ClKIN1
and CmKIN1 shared 98.48 and 90.51% identities to
AtKIN1 respectively, although they also contained
some mutation sites. Real-time quantitative PCR results
indicated that, during cold stress condition, transcripts of
CmCOR15b, ClKIN1 and CmKIN1
significantly increased, suggesting that they could take
part in the cold tolerance. However, ClCOR15b kept
stable during cold stress, implying that its role during
cold stress could be changed because of the lacked sequence.
Key
words:
Citrullus lanatus; Cucurbita moschata,
COR15b, KIN1, cold tolerance. |
