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

硒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，可以防止细胞的氧化损伤。相比之下，高等植物不需要Se，关于Se是否是植物的必需元素的问题仍然存在争议。以前的报道表明，微量的Se可能在抗氧化机制中发挥作用，并部分减轻镉对生长的不利影响。本工作的目的是研究Se和Se依赖调节因子在拟南芥幼苗中的新生理功能。在播种18天后，研究了0.1~100μM范围内补硒对拟南芥植株生物量的影响。当Se浓度大于50μM时，拟南芥幼苗地上部鲜重显著降低，但在含Se 0.5-5μM的基质中生长的幼苗鲜重显著高于不含Se的幼苗。与对照相比，补硒对叶片中的ATP含量和呼吸强度有显著影响。在含1μM Se的拟南芥幼苗中，依赖NAD的3-磷酸甘油醛脱氢酶和磷酸丙糖异构酶的活性是不含Se的幼苗的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.