Alterations in Enzyme Activities in Leaves after Exposure of Plectranthus Sp. Plants to 900 mhz elec
tải về 0.92 Mb. Chế độ xem pdf
|
ELECTROMAGNETICFIELDSandELF
| Materials and methods
Plectranthus is the largest South African genus of plants belonging to the mint family (Lamiaceae). There are many Plectranthus species (around 44) that are currently used as ornamental herbaceous plants throughout the world's gardens. Several species are grown as leaf vegetables, as root vegetables for their edible tubers, or as medicine. Plectranthus species are used as food plants by the larvae of some Lepidoptera species. Plants Plectrantus sp. were grown in a growing chamber at controlled temperature (23–24°C), light (30–40 mmol m – 2 s –1 ), humidity (60–65%) and photoperiod 12/12 h. The exposure was performed by GSM mobile phone type NSM-3, which was connected to a personal computer through an interface cable. The mobile phone was programmed via special software to emit carrier frequency 902 MHz (60 th uplink channel of GSM900). The signal included standard GSM modulation. GSM signal was pulsed. The duration of the pulses was 577 microseconds that corresponded to one time slot of TDMA frame. The TDMA frame in GSM systems has a duration 4.615 milliseconds. Discontinuous transmission mode (DTX) was off during all exposures. Mobile phone pulse output power was 2 W. Plants were exposed whole body to EM radiation from GSM mobile phone at 20 cm distance from the antenna for 1 hour. Alterations in enzyme activity in leaves were registered immediately after the end of the exposure and 1, 2 and 24 hours later. At the same time control pots were kept at the same conditions, but without exposure. Glucose-6-phosphate dehydrogenase activity was determined according to the method of Wakiuchi et al. (20). This metod, as well as the methods for determination of NADH-malate dehydrogenase and NADP-isocitrate dehydrogenase activities are described in Handbook of Plant Physiology (9). Protein quantity was determined according to the method of Bradford (3). The presented data are averages and standard deviations of 6 measurements for each term. The Student t-test was used to estimate the statistically significant differences between XI ANNIVERSARY SCIENTIFIC CONFERENCE BIOTECHNOL. & BIOTECHNOL. EQ. 23/2009/2 120 YEARS OF ACADEMIC EDUCATION IN BIOLOGY SPECIAL EDITION/ONLINE 45 YEARS FACULTY OF BIOLOGY 612 |