Porphyrin Biosynthesis and Antioxidant Properties are Influenced by Wavelength of LED-Light in Arabidopsis Seedlings

The effects of different light wavelengths on porphyrin biosynthesis and antioxidant mechanism were examined using different wavelengths from light emitting diodes (LED) with wavelengths of white LED (420-680 nm) as a control, blue LED (460-490 nm), green LED (520-550 nm), and red LED (620-650 nm). After 3 days of exposure to various wavelengths of LED lights, Arabidopsis seedlings treated with blue LED displayed significant increases in Mg-porphyrins including Mg-protoporphyrin IX (Mg-Proto IX), Mg-Proto IX methyl ester (ME), and protochlorophyllide, whereas red LED resulted in the lower levels of Mg-Proto IX and Mg-Proto IX ME, compared to white LED. Among various LEDs, blue LED induced the great increase in antioxidant property as indicated by increased transcript level of CatA, compared to white LED. Similarly, the blue-LED treatment greatly accumulated the amount of anthocyanin in Arabidopsis seedlings, compared to other wavelengths of LED lights. Our study demonstrates that different light wavelengths greatly influence plants’ physiological characteristics through altering porphyrin biosynthesis as well as antioxidant properties.