Cryptic red light signal regulates ascorbic acid in soybean.

The regulation of endogenous level of ascorbic acid in soybean (Glycine max L. Merrill) by cryptic red light signal (CRS) was studied. CRS is a cellular signal induced by red light pre-irradiation that amplifies the action of phytochrome, and is known to enhance anthocyanin synthesis in sorghum. A phytochrome-enhanced endogenous level of ascorbic acid in soybean seedlings was amplified by CRS. The lifetime of CRS was from 0 to 2h and the peak of enhancement was between 16 and 24h of dark incubation after the end of treatment.