OsSDIR1 overexpression greatly improves drought tolerance in transgenic rice
OsSDIR1 overexpression greatly improves drought tolerance in transgenic rice
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OsSDIR1过表达极大提高转基因水稻的耐旱性
DOI：
10.1007/s11103-011-9775-z
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发表时间：
2011-05-01
影响因子：
5.1
通讯作者：
Xie, Qi
中科院分区：
文献类型：
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作者：
Gao, Ting;Wu, Yaorong;Xie, Qi
最近对拟南芥进行的基因组和遗传分析表明，泛素化在植物对非生物胁迫和植物激素脱落酸(ABA)的响应中起着至关重要的作用。然而，在水稻中作为单子叶模式植物进行此类研究的报道很少。利用生物化学、分子细胞生物学和遗传学的策略，发现含有E3连接酶OsSDIR1的无名指(Oryza sativa Sales-and Different Ringing1)是作物工程中的一个候选抗旱基因。OsSDIR1在水稻各组织中均有表达，受干旱和盐胁迫的影响，但不受ABA的影响。体外泛素化实验表明，OsSDIR1是一种功能性的E3泛素连接酶，其活性需要位于无名指区域。OsSDIR1可以补充sdir1突变体的干旱敏感表型，并且过表达的转基因拟南芥对ABA更加敏感，这表明OsSDIR1基因是SDIR1的功能同源基因。在干旱处理后，转OsSDIR1基因水稻表现出比对照更强的抗旱性。气孔开度分析表明，转基因植株比对照植株有更多的闭合气孔。这一结果也被干旱处理过程中的失水测定和叶片相关含水率(RWC)测量所证实。因此，我们证明了单子叶和双子叶SDIR1是保守的，但具有不同的功能。
Recent genomic and genetic analyses based on Arabidopsis suggest that ubiquitination plays crucial roles in the plant response to abiotic stress and the phytohormone abscisic acid (ABA). However, few such studies have been reported in rice as a monocotyledonous model plant. Taking advantage of strategies in biochemistry, molecular cell biology and genetics, the RING-finger containing E3 ligase OsSDIR1 (Oryza sativa SALT-AND DROUGHT-INDUCED RING FINGER 1) was found to be a candidate drought tolerance gene for engineering of crop plants. The expression of OsSDIR1 was detected in all tissues of rice and up-regulated by drought and NaCl, but not by ABA. In vitro ubiquitination assays demonstrated that OsSDIR1 is a functional E3 ubiquitin ligase and that the RING finger region is required for its activity. OsSDIR1 could complement the drought sensitive phenotype of the sdir1 mutant and overexpressing transgenic Arabidopsis were more sensitive to ABA, indicating that the OsSDIR1 gene is a functional ortholog of SDIR1. Upon drought treatment, the OsSDIR1-transgenic rice showed strong drought tolerance compared to control plants. Analysis of the stomata aperture revealed that there were more closed stomatal pores in transgenic plants than those of control plants. This result was also confirmed by the water loss assay and leaf related water content (RWC) measurements during drought treatment. Thus, we demonstrated that monocot- and dicot- SDIR1s are conserved yet have diverse functions.