Contents of eight saccharides in unprocessed and processed Rehmannia glutinosa and content changes at different processing time points Effects of Ecological Factors on Raffinose Content in Soybean Seed Cloning and Expression of a Gene Encoding a Raffinose Synthase in the Resurrection Plant Boea hygrometrica Advance in Raffinose Family Oligosaccharides Metabolism and the Key Enzymes in Plants