Cátedra de Fisiología Vegetal, Facultad de Ciencias Naturales e IML, Universidad Nacional de Tucumán, CP 4000 Tucumán, Argentina.
Chemosphere. 2010 Oct;81(5):584-93. doi: 10.1016/j.chemosphere.2010.08.033. Epub 2010 Sep 15.
Seasonal variations in physiological and biochemical parameters of the aquatic fern Salvinia minima exposed to different Cr(VI) concentrations were studied. Growth, photosynthetic pigments, soluble carbohydrates, sucrose-related enzymes, lipid peroxidation, phenolics, and Cr accumulation in floating and submerged leaves were analyzed. Cr content was lower in winter than in summer, indicating that active metabolic events occurred in metal uptake. Leaf number and metal concentration factor were higher in summer than in winter. Relative growth rate (R(n)) indicated that growth was more affected by Cr in winter than in summer. Biochemical parameters showed great seasonal variations under increasing Cr. Hexose, starch, malondialdehyde and phenolic contents were greatest in winter, but R(n) and protein values were lowest. Sucrose content was highest in summer floating leaves. A great seasonal variability was observed in sucrose-related enzymes with the highest activities occurring in winter lipoxygenase was much higher in winter than in summer, indicating a strong lipid peroxidation. Results indicate that in Salvinia Cr causes seasonal perturbations in carbohydrate metabolism and oxidative stress by altering both sucrose-related enzymes and lipoxygenase activities. Variability in physiological and biochemical parameters seems to indicate that in outdoor conditions different mechanisms, in terms of Cr accumulation and tolerance, may occur in S. minima during summer and winter.
研究了暴露于不同 Cr(VI)浓度下的水生蕨类植物满江红的生理和生化参数的季节性变化。分析了浮叶和沉水叶的生长、光合色素、可溶性碳水化合物、蔗糖相关酶、脂质过氧化、酚类和 Cr 积累。冬季 Cr 含量低于夏季，表明金属吸收过程中发生了活跃的代谢事件。夏季的叶片数量和金属浓度系数高于冬季。相对生长率（R(n)）表明冬季 Cr 对生长的影响大于夏季。在 Cr 增加的情况下，生化参数显示出很大的季节性变化。冬季六碳糖、淀粉、丙二醛和酚类含量最高，但 R(n)和蛋白质值最低。夏季浮叶的蔗糖含量最高。与夏季相比，冬季脂肪氧合酶的活性更高，表明脂质过氧化作用较强。结果表明，Cr 通过改变蔗糖相关酶和脂肪氧合酶的活性，导致满江红在碳水化合物代谢和氧化应激方面产生季节性干扰。生理和生化参数的变异性似乎表明，在户外条件下，满江红在夏季和冬季可能会以不同的机制（在 Cr 积累和耐受性方面）来应对 Cr。
