Malerba Massimo, Cerana Raffaella
Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milan, Italy.
Dipartimento di Scienze dell'Ambiente e della Terra, Università degli Studi di Milano-Bicocca, 20126 Milan, Italy.
Plants (Basel). 2018 Aug 11;7(3):64. doi: 10.3390/plants7030064.
High temperatures are a significant stress factor for plants. In fact, many biochemical reactions involved in growth and development are sensitive to temperature. In particular, heat stress (HS) represents a severe issue for plant productivity and strategies to obtain high yields under this condition are important goals in agriculture. While selenium (Se) is a nutrient for humans and animals, its role as a plant micronutrient is still questioned. Se can prevent several abiotic stresses (drought, heat, UV, salinity, heavy metals), but the action mechanisms are poorly understood. Se seems to regulate reactive oxygen species (ROS) and to inhibit heavy metals transport. In addition, it has been demonstrated that Se is essential for a correct integrity of cell membranes and chloroplasts, especially the photosynthetic apparatus. Previous results showed that in tobacco ( cv. Bright-Yellow 2) cultures HS (5 min at 50 °C) induced cell death with apoptotic features, accompanied by oxidative stress and changes in the levels of stress-related proteins. In this work we investigated the effect of Se on the responses induced by HS. The obtained results show that Se markedly reduces the effects of HS on cell vitality, cytoplasmic shrinkage, superoxide anion production, membrane lipids peroxidation, activity of caspase-3-like proteases, and the levels of some stress-related proteins (Hsp90, BiP, 14-3-3s, cytochrome ).
高温是植物的一个重要胁迫因素。事实上，许多参与生长和发育的生化反应对温度敏感。特别是，热胁迫（HS）对植物生产力来说是一个严峻问题，在这种条件下实现高产的策略是农业中的重要目标。虽然硒（Se）是人和动物的一种营养元素，但其作为植物微量营养元素的作用仍受到质疑。硒可以预防多种非生物胁迫（干旱、高温、紫外线、盐度、重金属），但其作用机制尚不清楚。硒似乎能调节活性氧（ROS）并抑制重金属运输。此外，已经证明硒对于细胞膜和叶绿体尤其是光合机构的正确完整性至关重要。先前的结果表明，在烟草（品种：亮黄2）培养物中，热胁迫（50℃处理5分钟）诱导具有凋亡特征的细胞死亡，同时伴有氧化应激和应激相关蛋白水平的变化。在这项工作中，我们研究了硒对热胁迫诱导的反应的影响。所得结果表明，硒显著降低了热胁迫对细胞活力、细胞质收缩、超氧阴离子产生、膜脂过氧化、类半胱天冬酶 -3蛋白酶活性以及一些应激相关蛋白（热休克蛋白90、结合免疫球蛋白蛋白、14-3-3蛋白、细胞色素）水平的影响。
