Medical/biological study (experimental study)

Microwave pretreatment can enhance tolerance of wheat seedlings to CdCl(2) stress med./bio.

By: Qiu Z, Li J, Zhang Y, Bi Z, Wei H

Published in: Ecotoxicol Environ Saf 2011; 74 (4): 820-825

Aim of study (acc. to author)

The objectives of the study were 1) to determine the combined effects of microwave pretreatment and cadmium stress on wheat seedlings and 2) to evaluate the effect of seed pretreatment by microwaves on protecting wheat from cadmium (CdCl₂) stress damage using plant morphological and physiological indices.

Background/further details

Seeds were exposed to microwaves for 0, 5, 10 and 15 s (each n=1000) and when the seedlings were 7 days old (with one fully expanded leave), they were treated with 150 µM CdCl₂ solution for 10 days. On days 2, 4, 6, 8 and 10 leaves and roots were sampled for various analysis.

Endpoint

cadmium stress tolerance of wheat

Exposure

- 2.45 GHz
- microwaves
- microw. oven/heating device
- co-exposure

Exposure	Parameters
Exposure 1: 2,450 MHz Exposure duration: continuous for 5 s, 10 s or 15 s	power: 700 W power density: 126 mW/cm²

Exposure 1

Main characteristics

Frequency	2,450 MHz
Type	electromagnetic field
Exposure duration	continuous for 5 s, 10 s or 15 s

Exposure setup

Exposure source	microwave oven
Setup	seeds placed in the center of the microwave board
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power	700 W	-	-	-	-
power density	126 mW/cm²	-	-	-	-

Reference articles

Chen YP (2006): Microwave treatment of eight seconds protects cells of Isatis indigotica from enhanced UV-B radiation lesions

Exposed system:

plant
wheat (Triticum aestivum L.)

Methods Endpoint/measurement parameters/methodology

cadmium stress tolerance of wheat (growth parameters (plant height, root length, dry weight); oxidative stress parameters (enzyme activities of peroxidase, superoxide dismutase, catalase, ascorbate peroxidase; levels of the antioxidant compounds glutathione and ascorbate and of hydrogen peroxide, malondialdehyde (via thiobarbituric acid reactive substances) and superoxide; spectrophotometry))

Investigated system:

plants, leave homogenates and supernatants

Main outcome of study (acc. to author)

CdCl₂ treatment alone reduced plant height, root length, dry weight, ascorbate and glutathione concentrations and the enzyme activities of peroxidase, superoxide dismutase, catalase, ascorbate peroxidase, and enhanced the concentration of malondialdehyde, hydrogen peroxide and the production of superoxide when compared with the control.
However, seeds with microwave pretreatment for 5 or 10 s conferred a tolerance to cadmium stress in wheat seedlings by decreasing the concentration of malondialdehyde and hydrogen peroxide, the production of superoxide and increasing the enzyme activities of peroxidase, superoxide dismutase, catalase, ascorbate peroxidase and ascorbate and glutathione concentration. Therefore, antioxidative enzymes and antioxidative compounds may be involved in tolerance of wheat seedlings to cadmium stress. The findings also showed that the microwave exposure had a positive physiological effect on the growth and development of cadmium stressed seedlings (significant increase of root length and dry weight).

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Key Subject of Biochemistry and Molecular Biology of Henan Province, China
Ministry of Education, China
Opening Foundation of Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), China

Soran ML et al. (2014): Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants
Chen YP et al. (2009): Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings
Sharma VP et al. (2009): Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress
Tkalec M et al. (2007): Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L
Chen YP (2006): Microwave treatment of eight seconds protects cells of Isatis indigotica from enhanced UV-B radiation lesions
More HG et al. (1992): Effect of microwave heating on quality and mycoflora of sorghum grain