Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
Department of Plant Ecophysiology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland.
Int J Mol Sci. 2020 Aug 17;21(16):5899. doi: 10.3390/ijms21165899.
Though winter-hardiness is a complex trait, freezing tolerance was proved to be its main component. Species from temperate regions acquire tolerance to freezing in a process of cold acclimation, which is associated with the exposure of plants to low but non-freezing temperatures. However, mechanisms of cold acclimation in grasses, important for forage production in Europe, have not been fully recognized. Thus, two introgression forms with distinct freezing tolerance were used herein as models in the comprehensive research to dissect these mechanisms in that group of plants. The work was focused on: (i) analysis of cellular membranes' integrity; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gas exchange; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); (iii) analysis of plant antioxidant capacity (reactive oxygen species generation; gene expression, protein accumulation, and activity of selected enzymes); and (iv) analysis of Cor14b accumulation, under cold acclimation. The more freezing tolerant introgression form revealed a higher integrity of membranes, an ability to cold acclimate its photosynthetic apparatus and higher water use efficiency after three weeks of cold acclimation, as well as a higher capacity of the antioxidant system and a lower content of reactive oxygen species in low temperature.
尽管抗寒性是一个复杂的特征，但抗冻性被证明是其主要组成部分。来自温带地区的物种在冷驯化过程中获得抗冻性，这与植物暴露在低温但非冻结温度下有关。然而，禾本科植物的冷驯化机制尚未得到充分认识，禾本科植物对欧洲的饲料生产很重要。因此，本文使用了两种具有不同抗冻性的渐渗形式作为模型，对该组植物的这些机制进行了综合研究。这项工作的重点是：（i）分析细胞膜的完整性；（ii）分析植物的光合作用能力（叶绿素荧光；气体交换；基因表达、卡尔文循环选定酶的蛋白积累和活性）；（iii）分析植物的抗氧化能力（活性氧生成；基因表达、蛋白积累和选定酶的活性）；以及（iv）在冷驯化下分析 Cor14b 的积累。在经过三周的冷驯化后，具有更高抗冻性的渐渗形式表现出更高的膜完整性、使光合作用装置适应寒冷的能力以及更高的水分利用效率，以及更高的抗氧化系统能力和低温下活性氧含量更低。
