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Composition and content of lipids were studied in 5-day-old radish seedlings (Raphanus sativus L. var. radicula DC.) grown in lowlight and darkness in an extremely low frequency (ELF) magnetic field characterized by 50 Hz frequency and ∼500 µT flux density. The control seedlings were grown under the same conditions, but without exposure to the magnetic field. The products of lipid metabolism were compared with lipid composition in seeds. In control seedlings, reserve neutral lipids, mostly triacylglycerides, were utilized for the formation of polar lipids (PL). As a result, the amount of the latter doubled, particularly due to glycolipids (GL) and phospholipids (PhL) compared to their content in seeds. At 20-22 °C in light, magnetic field exposure increased the production of PL by threefold specifically, GL content increased fourfold and PhL content rose 2.5 times, compared to seeds. In darkness, the effect of magnetic field on lipids was weaker. At the lower temperature of 13-16 °C in light, the effect of the magnetic field was weak, but in the darkness, no magnetic field action was recorded. It is concluded that ELF magnetic field stimulated lipid synthesis in chloroplast, mitochondrial, and other cell membranes in radish seedlings grown in light at 20-22 °C and 13-16 °C.

Composition and content of lipids were studied in leaves of red perilla plants (Perilla nankinensis [Lour.] Decne.) grown in weak permanent horizontal magnetic field (PMF) of 500 µT flux density under controlled illumination, temperature, and humidity in the phytothron chamber. Control plants were grown under similar conditions, but without PMF exposure. Exposure of perilla plants for a month to PMF retarded plant flowering as compared to control. PMF treatment increased total lipid content, including polar lipids, among them glycolipids and phospholipids. PMF did not affect content of neutral lipids. It is concluded that PMF stimulated synthesis of membrane lipids of chloroplasts, mitochondria, and cytoplasm in perilla leaves. A possible role of PMF as a factor imitating the additional light source retarding flowering of a short-day perilla plants is discussed.

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