ABSTRACT

Selenium (Se) causes oxidative damage to plants. Proline is accumulated as a compatible solute in plants under stress conditions and mitigates stresses. Selenate at 250 µM increased cell death and inhibited the growth of tobacco BY-2 cells while exogenous proline at 10 mM did not mitigate the inhibition by selenate. Selenate increased accumulation of Se and ROS and activities of antioxidant enzymes but not lipid peroxidation in the BY-2 cells. Proline increased Se accumulation and antioxidant enzyme activities but not either ROS accumulation or lipid peroxidation in the selenate-stressed cells. Glutathione (GSH) rather than ascorbic acid (AsA) mitigated the growth inhibition although both reduced the accumulation of ROS induced by selenate. These results indicate that proline increases both antioxidant enzyme activities and Se accumulation, which overall fails to ameliorate the growth inhibition by selenate and that the growth inhibition is not accounted for only by ROS accumulation.

Abbreviations: APX: ascorbate peroxidase; AsA: ascorbic acid; BY-2: Bright Yellow-2; CAT: catalase; DAI: days after inoculation; DW: dry weight; FW: fresh weight; GSH: glutathione; ROS: reactive oxygen species

 抽象的

硒 (Se) 会对植物造成氧化损伤。脯氨酸在胁迫条件下作为相容性溶质在植物中积累并减轻胁迫。 250 µM 的硒酸盐会增加细胞死亡并抑制烟草 BY-2 细胞的生长，而 10 mM 的外源脯氨酸不会减轻硒酸盐的抑制作用。硒酸盐增加了 BY-2 细胞中 Se 和 ROS 的积累以及抗氧化酶的活性，但不增加脂质过氧化。脯氨酸增加硒积累和抗氧化酶活性，但不增加硒酸盐应激细胞中活性氧积累或脂质过氧化。谷胱甘肽 (GSH) 而不是抗坏血酸 (AsA) 减轻了生长抑制，尽管两者都减少了硒酸盐诱导的 ROS 积累。这些结果表明脯氨酸增加了抗氧化酶活性和硒积累，这总体上不能改善硒酸盐的生长抑制，并且生长抑制不仅仅由ROS积累来解释。

缩写： APX：抗坏血酸过氧化物酶； AsA：抗坏血酸； BY-2：亮黄-2； CAT：过氧化氢酶； DAI：接种后天数； DW：干重； FW：鲜重； GSH：谷胱甘肽； ROS：活性氧