Hormesis in Plants: The Role of Oxidative Stress, Auxins and Photosynthesis in Corn Treated with Cd or Pb

International Journal of Molecular Sciences

HazemM. Kalaji¹  Marta Pogrzeba²  Eugeniusz Małkowski³  Krzysztof Sitko³  Paulina Zieleźnik-Rusinowska³  Żaneta Gieroń³  Michał Szopiński³ 

[1] Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences WULS-SGGW, 02-776 Warsaw, Poland;Institute for Ecology of Industrial Areas, 40-844 Katowice, Poland;Plant Ecophysiology Team, Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, 40-032 Katowice, Poland;

关键词: hormesis;    growth;    photosynthesis;    chlorophyll a fluorescence;    cadmium;    lead;   

DOI  :  10.3390/ijms21062099

来源: DOAJ

【 摘 要 】

Hormesis, which describes the stimulatory effect of low doses of toxic substances on growth, is a well-known phenomenon in the plant and animal kingdoms. However, the mechanisms that are involved in this phenomenon are still poorly understood. We performed preliminary studies on corn coleoptile sections, which showed a positive correlation between the stimulation of growth by Cd or Pb and an increase in the auxin and H₂O₂ content in the coleoptile sections. Subsequently, we grew corn seedlings in hydroponic culture and tested a wide range of Cd or Pb concentrations in order to determine hormetic growth stimulation. In these seedlings the gas exchange and the chlorophyll a fluorescence, as well as the content of chlorophyll, flavonol, auxin and hydrogen peroxide, were measured. We found that during the hormetic stimulation of growth, the response of the photosynthetic apparatus to Cd and Pb differed significantly. While the application of Cd mostly caused a decrease in various photosynthetic parameters, the application of Pb stimulated some of them. Nevertheless, we discovered that the common features of the hormetic stimulation of shoot growth by heavy metals are an increase in the auxin and flavonol content and the maintenance of hydrogen peroxide at the same level as the control plants.

【 授权许可】

Unknown