Kováčik Jozef, Klejdus Bořivoj, Babula Petr, Soares Maria Elisa, Hedbavny Josef, de Lourdes Bastos Maria
Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic; CEITEC - Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic.
Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic; CEITEC - Central European Institute of Technology, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic.
J Inorg Biochem. 2015 Apr;145:70-8. doi: 10.1016/j.jinorgbio.2015.01.003. Epub 2015 Jan 17.
Uptake of trivalent chromium (Cr(III)-chloride), Cr speciation and consequences for the metabolism in chamomile plants with two ploidy levels have been studied. Depletion of fresh biomass, tissue water content and soluble proteins in response to high (120 μM) Cr(III) was ploidy-independent. Cr mainly accumulated in the roots (only negligibly in the shoots) and total root Cr amount was higher in tetraploid ones including the proof with specific fluorescent indicator (naphthalimide-rhodamine) of Cr(III). Quantification of Cr(VI) detected its higher content in tetraploid roots (up to 4.2% from total Cr), indicating partial oxidation of applied Cr(III). Higher H2O2 presence but lower activities of peroxidases were observed in tetraploid roots while nitric oxide, superoxide dismutase and glutathione reductase activities did not differ extensively. Soluble phenols, lignin, non-protein thiols, individual thiols (glutathione and phytochelatin 2) and ascorbic acid responded to high Cr(III) similarly in both cultivars while decrease of minerals was more pronounced in tetraploid ones. It seems that Cr(III)-induced oxidative stress arises from high root Cr uptake and Cr(VI) presence and is related to depletion of thiols. Assay of Krebs cycle acids confirmed rather depletion under 120 μM Cr(III) in both cultivars but increase in citric acid may indicate its involvement in root Cr chelation. Subsequent comparison of Cr(III)-chloride and Cr(III)-nitrate showed similar influence on Cr accumulation and majority of biochemical responses while different impact on phytochelatin 2 amount was the most distinct feature.
研究了具有两种倍性水平的洋甘菊植物对三价铬（氯化铬（III））的吸收、铬的形态以及对其新陈代谢的影响。响应高浓度（120 μM）铬（III）时，新鲜生物量、组织含水量和可溶性蛋白质的减少与倍性无关。铬主要积累在根部（地上部分积累极少），四倍体植物根部的总铬含量更高，包括用特定荧光指示剂（萘二甲酰亚胺 - 罗丹明）对铬（III）的验证。铬（VI）的定量分析检测到其在四倍体根部的含量更高（占总铬的4.2%），表明施用的铬（III）发生了部分氧化。在四倍体根部观察到过氧化氢含量较高，但过氧化物酶活性较低，而一氧化氮、超氧化物歧化酶和谷胱甘肽还原酶的活性差异不大。在两个品种中，可溶性酚类、木质素、非蛋白硫醇、单个硫醇（谷胱甘肽和植物螯合肽2）和抗坏血酸对高浓度铬（III）的反应相似，而四倍体中矿物质的减少更为明显。似乎铬（III）诱导的氧化应激源于根部对铬的高吸收和铬（VI）的存在，并且与硫醇的消耗有关。三羧酸循环酸的测定证实，在两个品种中，120 μM铬（III）处理下均出现了消耗，但柠檬酸的增加可能表明其参与了根部铬的螯合作用。随后对氯化铬（III）和硝酸铬（III）的比较表明，它们对铬积累和大多数生化反应的影响相似，而对植物螯合肽2含量的不同影响是最显著的特征。
