To study the effects of 900 MHz cell phone exposure on root formation in mung bean hypocotyls (stem of a germinating seedling, found below the seed leaves and above the root), a model system for rhizogenesis in plants.
16 glass vials (each containing five hypocotyls) were used for each exposure condition (including control). Each experiment (exposure condition) was repeated for three times. After the exposure, the hypocotyls were transferred into a growth chamber for seven days. For each enzymatic/biochemical analysis, there were five replicated tissue samples.
|Distance between exposed object and exposure source
|with 2 mm thick aluminum sheets shielded 47.5 cm x 27 cm x 17.5 cm chamber
|two cell phones placed along the chamber's walls; 12 glass vials containing the hypocotyls positioned between them (according to the figure in the article); constant temperature of 25 +/- 1°C inside the chamber
|A sham exposure was conducted.
The number of roots per hypocotyl and the average root length decreased significantly in response to cell phone exposure. The inhibitory effect increased with the period of exposure time. Additionally, the length of emerged roots was lesser in exposed hypocotyls.
The cell phone exposure enhanced the enzyme activities of proteases, polyphenol oxidases, and peroxidases in mung bean hypocotyls in comparison with the control. Furthermore, the electromagnetic field exposure enhanced the malondialdehyde level, the hydrogen peroxide, and proline content, indicating a reactive oxygen species-mediated oxidative damage in the hypocotyls. This was confirmed by the upregulation in the enzyme activities of all antioxidant enzymes suggesting their possible role in providing protection against mobile phone exposure-induced oxidative damage.
The authors concluded that cell phone exposure affect (inhibit) the process of rhizogenesis through biochemical alterations that manifest as oxidative damage resulting in root impairment.