过量表达URO基因提高拟南芥的抗旱能力

庞静洋*, 倪伟平*, 杨扬, 徐艳飞, 李玲, 杨美良, 李小方, 孙越**
华东师范大学生命科学学院, 上海200241 * 对本工作贡献相同。

通信作者: 孙越;E-mail: ysun@bio.ecnu.edu.cn;Tel: 021-54341016

摘 要:

拟南芥uro突变体中由于URO (UpRight ROsette)基因的过量表达导致生长素含量明显提高。本文结果表明, uro突变体的抗旱能力明显强于野生型, 但uro突变体的根长、表皮毛数目以及离体叶的脱水速度都没有优于野生型。uro突变体对外源ABA不敏感, 且在uro突变体中ABA响应基因的表达与野生型相比显著推迟。另外, 表型分析表明uro突变体的营养生长延长, 植株衰老延迟, 特别是经过渗透胁迫后, uro植株内的丙二醛含量低于野生型。由此可见, URO基因的过量表达使uro突变体通过ABA非依赖途径提高了抗旱能力, 而且uro突变体衰老延迟可能与其干旱抗性提高有关。

关键词:抗旱; 水分胁迫; 生长素; ABA; URO基因; 衰老

收稿:2013-03-11   修定:2013-07-03

资助:国家自然科学基金(31270332和3057015)

Overexpression of URO Gene Enhances Drought Resistance in Arabidopsis

PANG Jing-Yang*, NI Wei-Ping*, YANG Yang, XU Yan-Fei, LI Ling, YANG Mei-Liang, LI Xiao-Fang, SUN Yue**
school of Life sciences, east China Normal University, shanghai 200241, China

Corresponding author: PANG Jing-Yang; E-mail: ysun@bio.ecnu.edu.cn; Tel: 021-54341016

Abstract:

Arabidopsis uro mutant has higher IAA content than wild-type plants because of URO (UpRight ROsette) gene overexpression. In this study, the results showed that uro mutant displayed improved drought tolerance compared to wild type. However, no evidence showed uro mutant had any drought tolerance related phenotypes such as root length, number of trichomes and the speed of cellular dehydration of leaf explants. In addition, uro mutant exhibited decreased sensitivity to exogenous abscisic acid (ABA). At the same time, the enhanced expression of ABA-responsive genes in uro mutant was delayed obviously relative to wild type after ABA treatment. On the other hand, uro mutant has prolonged vegetable growth and delayed senescence. Especially after osmotic stress treatment, there was much less malondialdehyde (MDA) in uro mutant than in wild type. These results indicate that overexpression of URO gene enhances drought tolerance of uro mutant through an ABA-independent pathway, and the delayed senescence of uro mutant may relate to its high drought tolerance.

Key words: drought resistance; water stress; auxin; ABA; URO; senescence

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