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The effects of
cryptochrome photoreceptors on root growth in Arabidopsis
Jianxin Zeng, Qiming Wang,
Jianzhong Lin, Keqin Deng, Dongying Tang, Xiaoying Zhao and
Xuanming Liu*
Bioenergy
and Biomaterial Research Center Bioscience and Biotechnology
Institute, Hunan University, Changsha 410082, China.
*Corresponding author. E-mail:
sw_xml@hnu.cn.
Tel.:
+86(0) 731-8821721.
Fax: +86(0) 731-8822606.
Abbreviations:
IAA,
Indoleacetic acid;
NPA, 1-naphthylphthalamic acid; PIN1,
Pin-formed1; PIN2, Pin-formed2.
Accepted 8
May, 2009 |
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Cryptochrome mutants were examined to assess their potential
roles in root growth. Compared to root elongation of wild
type, the cryptochrome mutant seedlings showed increased
root elongation in blue light. Cry1cry2 seedlings
have the longest root elongation and
cry1
seedlings showed slightly increased root elongation than
cry2 seedlings. During this process,
CRY1
play the largest role and
CRY2
play lesser role, indicating that
CRY1
and
CRY2
act synergistic role in root growth. The auxin transport inhibitor NPA abolished the differential
effect of cryptochromes on root growth. Moreover, expression
of PIN1 in
CRY1
over-expression (Oecry1) transgenic seedlings was
half of that in wild type. Taken together, these results
revealed that the cryptochrome photoreceptors regulate root
growth by changing auxin transport.
Key
words:
Arabidopsis, auxin, blue light, cryptochrome,
root elongation. |
