Expression of a rice glutaredoxin in aleurone layers of developing and mature seeds: subcellular localization and possible functions in antioxidant defense
Expression of a rice glutaredoxin in aleurone layers of developing and mature seeds: subcellular localization and possible functions in antioxidant defense
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DOI：
10.1007/s00425-015-2354-9
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发表时间：
2015-11-01
期刊：
影响因子：
4.3
通讯作者：
Satoh, Shigeru
中科院分区：
文献类型：
--
作者：
Morita, Shigeto;Yamashita, Yuki;Satoh, Shigeru
水稻谷氧还蛋白（OsGrxC 2;2）在种子组织中大量表达，并定位于发育和成熟种子糊粉层的贮藏液泡中，具有抗氧化能力，在种子发育后期，种子组织经历了剧烈的失水，因此需要耐受与脱水相关的氧化损伤。我们以前发现了一个水稻谷氧还蛋白亚型，OsGrxC 2;2，作为一个基因在发育种子中大量表达。由于谷氧还蛋白参与抗氧化防御，在本研究中，我们研究了OsGrxC 2;2的亚细胞定位和表达谱，以及OsGrxC 2;2是否在防御活性氧自由基的作用。Western blotting和免疫组化结果表明，OsGrxC 2;2蛋白在发育和成熟种子的胚和糊粉层中大量积累。OsGrxC 2;2在发育种子中特别定位于糊粉粒，糊粉粒是来自液泡的储存细胞器。OsGrxC 2;2的过表达增强了转基因水稻植株对酵母中甲萘醌和绿色叶片中甲基紫精的耐受性。这些结果表明OsGrxC 2;2参与了种子发育和成熟过程中对氧化胁迫的防御。
A rice glutaredoxin isoform (OsGrxC2;2) with antioxidant capacity is expressed abundantly in seed tissues and is localized to storage vacuoles in aleurone layers in developing and mature seeds.Seed tissues undergo drastic water loss at the late stage of seed development, and thus need to tolerate oxidative injuries associated with desiccation. We previously found a rice glutaredoxin isoform, OsGrxC2;2, as a gene expressed abundantly in developing seeds. Since glutaredoxin is involved in antioxidant defense, in the present study we investigated the subcellular localization and expression profile of OsGrxC2;2 and whether OsGrxC2;2 has a role in the defense against reactive oxygen species. Western blotting and immunohistochemistry revealed that the OsGrxC2;2 protein accumulated at a high level in the embryo and aleurone layers of developing and mature seeds. The OsGrxC2;2 in developing seeds was particularly localized to aleurone grains, which are storage organelles derived from vacuoles. Overexpression of OsGrxC2;2 resulted in an enhanced tolerance to menadione in yeast and methyl viologen in green leaves of transgenic rice plants. These results suggest that OsGrxC2;2 participates in the defense against oxidative stress in developing and mature seeds.