Novel physiological function of selenium and selenium-dependent regulatory factor in Arabidopsis thaliana.

硒（Se）被认为是动物和人类必需的微量元素，因为它是谷胱甘肽过氧化物酶的组成部分，谷胱甘肽过氧化物酶是一种硒酶，可以防止细胞氧化损伤。相比之下，高等植物不需要硒，硒是否是植物必需元素的问题仍然存在争议。以前的报道认为微量硒可能在抗氧化机制中起作用，并部分减轻镉对生长的不利影响。本研究旨在探讨硒和硒依赖调节因子在拟南芥幼苗中的新生理功能。研究了在0.1 ~ 100 μM范围内添加硒（Se）对播种后18 d拟南芥植株生物量的影响。大于50 μM的处理显著降低了拟南芥幼苗的鲜重。但在0.5 ~ 5 μM Se培养基中生长的幼苗鲜重显著高于未添加Se的幼苗。与对照植株相比，硒对ATP含量和呼吸有显著影响。在添加1 μM Se的培养基中，拟南芥幼苗的NAD依赖性甘油醛-3-磷酸脱氢酶和三磷酸异构酶活性比不添加Se的幼苗高1.5倍。

Selenium (Se) has been recognized as an essential trace element for animal and human because it is an integral part of the enzyme glutathione peroxidase, a seleno enzyme that prevents oxidative damage to cells. In contrast, higher plants do not require Se, and the question of whether Se is an essential element to plants remains controversial. Previous reports suggest that trace amounts of Se may serve a role in antioxidative mechanisms and partially reduce the adverse effects of cadmium on the growth. The aim of this work was to investigate novel physiological function of Se and Se-dependent regulatory factor in Arabidopsis thaliana seedlings. The influence of Se (sodium selenate) supplementation in the range of 0.1-100 μM on the biomass of Arabidopsis plants was studied 18 days after sowing. A significant decrease in the shoot fresh weight of Arabidopsis seedlings was noted at greater than 50 μM. However, the fresh weight of the seedlings grown in the medium with 0.5-5 μM Se significantly increased over that of seedlings grown without Se. There was significant effect of Se supplementation on the ATP content and respiration, as compared with control plants. In Arabidopsis seedlings grown in the medium with 1 μM Se, NAD dependent glyceraldehyde-3-phosphate dehydrogenase and triosephosphate isomerase activities were 1.5-fold higher than those in seedlings grown without Se.