Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB)-Instituto de Agroecología y Economía del Agua (INAGEA), Palma de Mallorca, Spain.
Systems Biology and Mathematical Modeling Group, Max-Planck-Institut für Molekulare Pflanzenphysiologie, 14476 Potsdam, Germany.
Plant Cell Environ. 2020 Jun;43(6):1376-1393. doi: 10.1111/pce.13737. Epub 2020 Feb 24.
The species Deschampsia antarctica (DA) is one of the only two native vascular species that live in Antarctica. We performed ecophysiological, biochemical, and metabolomic studies to investigate the responses of DA to low temperature. In parallel, we assessed the responses in a non-Antarctic reference species (Triticum aestivum [TA]) from the same family (Poaceae). At low temperature (4°C), both species showed lower photosynthetic rates (reductions were 70% and 80% for DA and TA, respectively) and symptoms of oxidative stress but opposite responses of antioxidant enzymes (peroxidases and catalase). We employed fused least absolute shrinkage and selection operator statistical modelling to associate the species-dependent physiological and antioxidant responses to primary metabolism. Model results for DA indicated associations with osmoprotection, cell wall remodelling, membrane stabilization, and antioxidant secondary metabolism (synthesis of flavonols and phenylpropanoids), coordinated with nutrient mobilization from source to sink tissues (confirmed by elemental analysis), which were not observed in TA. The metabolic behaviour of DA, with significant changes in particular metabolites, was compared with a newly compiled multispecies dataset showing a general accumulation of metabolites in response to low temperatures. Altogether, the responses displayed by DA suggest a compromise between catabolism and maintenance of leaf functionality.
南极发草（DA）是仅有的两种生活在南极洲的本地维管束植物之一。我们进行了生理生态、生物化学和代谢组学研究，以研究 DA 对低温的响应。同时，我们评估了来自同一科（禾本科）的非南极参考物种（普通小麦 TA）的响应。在低温（4°C）下，两种物种的光合速率均降低（DA 和 TA 分别降低了 70%和 80%），且出现氧化应激症状，但抗氧化酶（过氧化物酶和过氧化氢酶）的反应相反。我们采用融合最小绝对收缩和选择算子统计模型，将依赖于物种的生理和抗氧化反应与初级代谢相关联。对 DA 的模型结果表明，与渗透保护、细胞壁重塑、膜稳定和抗氧化次生代谢（类黄酮和苯丙烷类合成）有关，与从源到汇组织的养分动员相协调（通过元素分析证实），而在 TA 中则没有观察到。与新汇编的多物种数据集相比，DA 的代谢行为表现出特定代谢物的显著变化，该数据集显示低温响应下代谢物的一般积累。总的来说，DA 表现出的响应表明在分解代谢和维持叶片功能之间存在一种妥协。
