Organic Soil Amendments in Assisted Phytoremediation of Heavy Metals Contaminated Soil - Basic Phytotoxicity Markers

Abstract

Organiczne dodatki we wspomaganej fitoremediacji gleb zanieczyszczonych metalami ciężkimi -podstawowe markery fitotoksyczności Abiotic and biotic stressors induce a strong cellular response in plants, resulting in significant changes in plant cells metabolism. Knowledge in this area can help to develop very specific methods of stress decrease. For this purpose, it is necessary to find sensitive and accurate tools that will allow to estimate the level of stress in cells. The largest group of substances involved in stress response are proteins. The study of changes in the protein profile can yield the most answers concerning the different mechanisms of soil microflora tolerance and the adaptation of plants to unfavorable conditions. The knowledge of these mechanisms can significantly support the assisted phytoremediation of soils. The aim of the study was to investigate the effect of abiotic factors on plant stress response in Lupinus luteus grown on soil contaminated with heavy metals and amended with organic additives. The aim of the study was to determine the level of plant stress based on tests of plant stress proteins presence and a specific peroxidase activity in plants grown on soil contaminated with heavy metals (HMs). An acrylamide gel electrophoresis (SDS-PAGE) has been used in the study to separate specific proteins fractions (metallothioneins), accompanying stress factors. The results of peroxidase activity indicated that the organic soil amendments have an impact on reducing plant stress. The lowest dose of soil amendments reduced the amount of peroxidase by almost half in roots. This proves that adequate soil supplementation helps plants to tolerate stress. The SDS-PAGE analysis suggests that in the most stressful conditions the protein profile is significantly different from control and indicates additional small protein products in the range of 7÷20 kDa indicating, in accordance with the literature, presence of metallothioneins as response to plant stress. The applied methodology confirms that organic soil amendments reduced the level of HMs plants stress after organic amendments soil application.