Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska Dolina B2, Ilkovicova 6, 842 15, Bratislava, Slovakia.
Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska Dolina B2, Ilkovicova 6, 842 15, Bratislava, Slovakia; Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska Cesta 9, 845 23, Bratislava, Slovakia.
Plant Physiol Biochem. 2021 Nov;168:155-166. doi: 10.1016/j.plaphy.2021.10.012. Epub 2021 Oct 5.
Nowadays, one of the biggest challenges of plant physiology is to find out the ways how to mitigate negative impacts of abiotic stress on plants. It is the pollution of groundwater or soil by various metals and metalloids that significantly affects the quality of life. Both arsenic (As) and silicon (Si) are metalloids - while the first one is toxic in general, the latter one is considered as beneficial for plants suffering from various kinds of stresses. The aim of our work was to elucidate the growth and development of young maize (Zea mays L.) plants exposed to both of these metalloids simultaneously. Experiments were focused on the comparison of root growth and biomass allocation, changes in uptake of macro- and micronutrients, visualisation of free radicals along with monitoring of the dynamics of main antioxidant enzymes activity in roots. The results showed that increasing concentration of As (75 and 150 μM As) severely inhibited root length and the amount of biomass, and addition of Si (2.5 mM) to the medium containing As did not have a significant effect on root growth. Similarly, the application of Si did not influence the uptake of macro- and microelements into the roots (mainly Ca, P, K, Mo, Cu, Zn and Ni) which was mostly decreased due to As. On the other hand, Si significantly decreased the presence of both superoxide and hydrogen peroxide in roots that suffered from As toxicity. Although the overall growth of maize plants was not improved by Si amendment, we assume that Si might affect the functionality of key antioxidant enzymes in time, and in this way at least partially help to overcome negative effects of As on maize roots.
如今，植物生理学面临的最大挑战之一是找出减轻非生物胁迫对植物负面影响的方法。正是各种金属和类金属对地下水和土壤的污染，极大地影响了生活质量。砷（As）和硅（Si）都是类金属——虽然前者通常是有毒的，但后者被认为对各种胁迫下的植物有益。我们工作的目的是阐明同时暴露于这两种类金属的幼玉米（Zea mays L.）植物的生长和发育情况。实验重点比较了根的生长和生物量分配的变化、对大量和微量元素的吸收变化、自由基的可视化以及监测根中主要抗氧化酶活性的动态。结果表明，随着 As 浓度的增加（75 和 150 μM As），根长和生物量严重受到抑制，向含 As 的培养基中添加 Si（2.5 mM）对根的生长没有显著影响。同样，Si 的应用也没有影响根对大量和微量元素（主要是 Ca、P、K、Mo、Cu、Zn 和 Ni）的吸收，这些元素主要因 As 的存在而减少。另一方面，Si 显著减少了受 As 毒性影响的根中超氧化物和过氧化氢的存在。尽管 Si 的添加并没有改善玉米植株的整体生长，但我们假设 Si 可能会影响关键抗氧化酶的功能，从而在一定程度上帮助玉米根克服 As 的负面影响。
