Tiecher Tadeu L, Ceretta Carlos A, Tiecher Tales, Ferreira Paulo A A, Nicoloso Fernando T, Soriani Hilda H, Rossato Liana V, Mimmo Tanja, Cesco Stefano, Lourenzi Cledimar R, Giachini Admir J, Brunetto Gustavo
Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
Departamento de Ciência do Solo da Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
Ecotoxicol Environ Saf. 2016 Jul;129:109-19. doi: 10.1016/j.ecoenv.2016.03.016. Epub 2016 Mar 21.
The occurrence of high levels of Cu in vineyard soils is often the result of intensive use of fungicides for the preventive control of foliar diseases and can cause toxicity to plants. Nowadays many grape growers in Southern Brazil have replaced Cu-based with Zn-based products. The aim of the study was to evaluate whether the increase in Zn concentration in a soil with high Cu contents can interfere with the dynamics of these elements, and if this increase in Zn may cause toxicity to maize (Zea mays L.). Soil samples were collected in two areas, one in a vineyard with more than 30 years of cultivation and high concentration of Cu and the other on a natural grassland area adjacent to the vineyard. Different doses of Cu and Zn were added to the soil, and the adsorption isotherms were built following the Langmuir's model. In a second experiment, the vineyard soil was spiked with different Zn concentrations (0, 30, 60, 90, 180, and 270mg Zn kg(-1)) in 3kg pots where maize was grown in a greenhouse for 35 days. When Cu and Zn were added together, there was a reduction in the quantities adsorbed, especially for Zn. Zn addition decreased the total plant dry matter and specific leaf mass. Furthermore, with the increase in the activity of catalase, an activation of the antioxidant system was observed. However, the system was not sufficiently effective to reverse the stress levels imposed on soil, especially in plants grown in the highest doses of Zn. At doses higher than 90Znmgkg(-1) in the Cu-contaminated vineyard soil, maize plants were no longer able to activate the protection mechanism and suffered from metal stress, resulting in suppressed dry matter yields due to impaired functioning of the photosynthetic apparatus and changes in the enzymatic activity of plants. Replacement of Cu- by Zn-based fungicides to avoid Cu toxicity has resulted in soil vineyards contaminated with these metals and damaging of plant photosynthetic apparatus and enzyme activity.
葡萄园土壤中高含量铜的出现通常是由于大量使用杀菌剂来预防性控制叶部病害所致，这可能会对植物产生毒性。如今，巴西南部的许多葡萄种植者已用锌基产品取代了铜基产品。本研究的目的是评估在高铜含量土壤中增加锌浓度是否会干扰这些元素的动态变化，以及这种锌浓度的增加是否会对玉米（Zea mays L.）产生毒性。在两个区域采集了土壤样本，一个是种植超过30年且铜浓度高的葡萄园，另一个是葡萄园附近的天然草地。向土壤中添加了不同剂量的铜和锌，并根据朗缪尔模型建立了吸附等温线。在第二个实验中，在3千克花盆中向葡萄园土壤添加不同浓度的锌（0、30、60、90、180和270毫克锌/千克(-1)），在温室中种植玉米35天。当铜和锌一起添加时，吸附量减少，尤其是锌。添加锌降低了植物总干物质和比叶质量。此外，随着过氧化氢酶活性的增加，观察到抗氧化系统被激活。然而，该系统不足以有效逆转施加在土壤上的胁迫水平，尤其是在锌含量最高剂量下生长的植物中。在铜污染的葡萄园土壤中，锌剂量高于90毫克/千克(-1)时，玉米植株不再能够激活保护机制并遭受金属胁迫，由于光合器官功能受损和植物酶活性变化，导致干物质产量受到抑制。用锌基杀菌剂替代铜基杀菌剂以避免铜毒性，已导致葡萄园土壤被这些金属污染，并损害了植物的光合器官和酶活性。
