Specific roles of tocopherols and tocotrienols in seed longevity and germination tolerance to abiotic stress in transgenic rice
Specific roles of tocopherols and tocotrienols in seed longevity and germination tolerance to abiotic stress in transgenic rice
复制标题
生育酚和生育三烯酚在转基因水稻种子寿命和对非生物胁迫的发芽耐受性中的具体作用
DOI：
10.1016/j.plantsci.2015.12.005
复制
发表时间：
2016-03-01
期刊：
影响因子：
5.2
通讯作者：
Chen, Xiwen
中科院分区：
文献类型：
--
作者：
Chen, Defu;Li, Yanlan;Chen, Xiwen
生育酚和生育三烯酚是亲脂性抗氧化剂，在植物种子中含量丰富。尽管它们的作用已被广泛研究，但我们对它们在水稻种子中的功能的了解仍然有限。在本研究中，基于现有的尿黑酸植基转移酶（HPT）和生育酚环化酶（TC）沉默的RNAi水稻植物，我们开发了沉默尿黑酸香叶基香叶基转移酶（HGGT）的转基因植物。与对照植物相比，所有RNAi植物的发芽率均显着降低，异常幼苗的比例更高，其中HGGT转基因表现出最严重的表型。加速衰老表型与胚胎中积累的 H2O2 量、葡萄糖水平和离子泄漏很好地对应，但与这些基因型中胚胎中积累的 O-2- 量和脂质氢过氧化物水平不相符。在非生物胁迫条件下，HPT和TC转基因比HGGT转基因表现出较低的发芽率和幼苗生长，而HGGT转基因表现出与野生型几乎相同的状态。因此，我们提出，在加速老化和应激条件下，胚芽中的生育酚可以保护胚胎免受活性氧的影响，而果皮中的生育三烯酚可能专门有助于降低加速老化期间种子的代谢活动。 (C) 2015 Elsevier Ireland Ltd. 保留所有权利。
Tocopherols and tocotrienols are lipophilic antioxidants that are abundant in plant seeds. Although their roles have been extensively studied, our understanding of their functions in rice seeds is still limited. In this study, on the basis of available RNAi rice plants constitutively silenced for homogentisate phytyltransferase (HPT) and tocopherol cyclase (TC), we developed transgenic plants that silenced homogentisate geranylgeranyl transferase (HGGT). All the RNAi plants showed significantly reduced germination percentages and a higher proportion of abnormal seedlings than the control plants, with HGGT transgenics showing the most severe phenotype. The accelerated aging phenotype corresponded well with the amount of H2O2 accumulated in the embryo, glucose level, and ion leakage, but not with the amount of O-2- accumulated in the embryo and lipid hydroperoxides levels in these genotypes. Under abiotic stress conditions, HPT and TC transgenics showed lower germination percentage and seedling growth than HGGT transgenics, while HGGT transgenics showed almost the same status as the wild type. Therefore, we proposed that tocopherols in the germ may protect the embryo from reactive oxygen species under both accelerated aging and stress conditions, whereas tocotrienols in the pericarp may exclusively help in reducing the metabolic activity of the seed during accelerated aging. (C) 2015 Elsevier Ireland Ltd. All rights reserved.