AbdElgawad Hamada, Farfan-Vignolo Evelyn Roxana, de Vos Dirk, Asard Han
Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020 Antwerp, Belgium.
Laboratory for Molecular Plant Physiology and Biotechnology, Department of Biology, University of Antwerp, B-2020 Antwerp, Belgium; Department of Mathematics and Computer Science, University of Antwerp, B-2020 Antwerp, Belgium.
Plant Sci. 2015 Feb;231:1-10. doi: 10.1016/j.plantsci.2014.11.001. Epub 2014 Nov 18.
Increasing atmospheric CO2 will affect plant growth, including mitigation of stress impact. Such effects vary considerably between species-groups. Grasses (Lolium perenne, Poa pratensis) and legumes (Medicago lupulina, Lotus corniculatus) were subjected to drought, elevated temperature and elevated CO2. Drought inhibited plant growth, photosynthesis and stomatal conductance, and induced osmolytes and antioxidants in all species. In contrast, oxidative damage was more strongly induced in the legumes than in the grasses. Warming generally exacerbated drought effects, whereas elevated CO2 reduced stress impact. In the grasses, photosynthesis and chlorophyll levels were more protected by CO2 than in the legumes. Oxidative stress parameters (lipid peroxidation, H2O2 levels), on the other hand, were generally more reduced in the legumes. This is consistent with changes in molecular antioxidants, which were reduced by elevated CO2 in the grasses, but not in the legumes. Antioxidant enzymes decreased similarly in both species-groups. The ascorbate-glutathione cycle was little affected by drought and CO2. Overall, elevated CO2 reduced drought effects in grasses and legumes, and this mitigation was stronger in the legumes. This is possibly explained by stronger reduction in H2O2 generation (photorespiration and NADPH oxidase), and a higher availability of molecular antioxidants. The grass/legume-specificity was supported by principal component analysis.
大气中二氧化碳浓度增加会影响植物生长，包括减轻胁迫影响。这些影响在不同物种组之间差异很大。对禾本科植物（多年生黑麦草、草地早熟禾）和豆科植物（天蓝苜蓿、百脉根）进行干旱、高温和高二氧化碳处理。干旱抑制了所有物种的植物生长、光合作用和气孔导度，并诱导了渗透调节物质和抗氧化剂的产生。相比之下，豆科植物比禾本科植物更容易受到氧化损伤。升温通常会加剧干旱影响，而高二氧化碳浓度则会减轻胁迫影响。在禾本科植物中，二氧化碳对光合作用和叶绿素水平的保护作用比豆科植物更强。另一方面，豆科植物中的氧化应激参数（脂质过氧化、过氧化氢水平）通常降低得更多。这与分子抗氧化剂的变化一致，禾本科植物中高二氧化碳浓度会使其减少，而豆科植物则不然。两个物种组中的抗氧化酶下降情况相似。抗坏血酸-谷胱甘肽循环受干旱和二氧化碳的影响较小。总体而言，高二氧化碳浓度减轻了禾本科植物和豆科植物的干旱影响，且这种减轻作用在豆科植物中更强。这可能是由于过氧化氢生成（光呼吸和NADPH氧化酶）的更强减少以及分子抗氧化剂的更高可用性所致。主成分分析支持了禾本科植物/豆科植物的特异性。
