Department of Plant Physiology, Lublin University of Life Sciences, Akademicka 15, 20-950 Lublin, Poland.
Biol Trace Elem Res. 2010 Dec;138(1-3):307-15. doi: 10.1007/s12011-010-8613-5. Epub 2010 Feb 6.
The objective of this study was to investigate the effect of selenium (Se) supply (0, control; 2.5, 5, 10, or 20 μM) on cucumber (Cucumis sativus L.) cv. Polan F1 plants grown under short-term low temperature stress. About 14-16 day-old seedlings, grown at an optimal temperature (25/20°C; day/night), were exposed to short-term chilling stress with a day/night temperature of 10°C/5°C for 24 h, for a further 24 h at 20°C/15°C, and then transferred to 25/20°C (re-warming) for 7 days. Se did not affect the fresh weight (FW) of plants at a concentration of 2.5-10 μM, but in the presence of 20 μM Se, the biomass of shoots significantly decreased. The contents of chlorophylls and carotenoids witnessed no significant change after Se supplementation. Compared with the control, the Se-treated plants showed an increase of proline content in leaves, once after chilling and again after 7 days of re-warming. However, proline levels were much higher immediately after chilling than after re-warming. The malondialdehyde (MDA) content in the root of plants treated with 2.5-10 μM Se decreased directly after stress. This was in comparison with the plants grown without Se, whereas it increased in roots and leaves of plants exposed to 20 μM Se. Seven days later, the MDA level in the root of plants grown in the presence of Se was still lower than those of plants not treated with Se and generally witnessed no significant change in leaves. Although Se at concentrations of 2.5-10 μM modified the physiological response of cucumber to short-term chilling stress, causing an increase in proline content in leaves and diminishing lipid peroxidation in roots, the resistance of plants to low temperature was not clearly enhanced, as concluded on the basis of FW and photosynthetic pigments accumulation.
本研究旨在探讨硒（Se）供应（0，对照；2.5、5、10 或 20 μM）对短期低温胁迫下生长的黄瓜（Cucumis sativus L.）cv. Polan F1 植株的影响。约 14-16 天大的幼苗在最佳温度（25/20°C；白天/夜间）下生长，然后暴露于短期冷胁迫下，白天/夜间温度为 10°C/5°C 24 h，再在 20°C/15°C下进一步生长 24 h，然后转移到 25/20°C（复温）7 天。在 2.5-10 μM 的浓度下，Se 不影响植物的鲜重（FW），但在 20 μM Se 的存在下，茎的生物量显著减少。补充 Se 后，叶绿素和类胡萝卜素的含量没有明显变化。与对照相比，Se 处理的植物叶片中脯氨酸含量增加，在冷胁迫后和复温后 7 天再次增加。然而，冷胁迫后脯氨酸水平立即高于复温后。在根中，用 2.5-10 μM Se 处理的植物在胁迫后直接降低丙二醛（MDA）的含量。与未添加 Se 的植物相比，在添加 20 μM Se 的植物中，根和叶中的 MDA 含量增加。7 天后，在添加 Se 的植物根中的 MDA 水平仍低于未添加 Se 的植物，并且通常在叶片中没有明显变化。尽管浓度为 2.5-10 μM 的 Se 改变了黄瓜对短期冷胁迫的生理反应，导致叶片中脯氨酸含量增加，根系脂质过氧化减少，但基于 FW 和光合色素积累，植物对低温的抗性并未明显增强。
