The application of DNA demethylation in alteration of phenotypic, seed production, protein lipid content and fatty acid composition in soybean cultivar SJ. 5

Abstract

To evaluate the demethylating effects of 5-azaC on the general phenotypes, protein content, oil content and fatty acid composition at the whole plant system, soybean plants (Glycine max (L.) Merrill) var. SJ.5 have been submitted to 5-azaC treatment. In in vitro culture, seeds were cultured in MS media containing 5-azaC at the concentration of 0, 300, 600, 900, 1200 and 1500 micromolar for 10 days. The 5-azaC-treated seedlings exhibited normal morphology in comparison with the controls except that their height and root length were significantly shorter than that of the controls, and were dose dependent. The isolated genomic DNAs showed hypomethylation as compared with that of the controls. In the field culture, seeds were treated for 16 h with 5-azaC solution at 0, 300, 600, 900, 1200 and 1500 micromolar. The treatment induced tall plant and high node number, without apparently affecting any other developmental processes. Studies on the effects of 5-azaC on the protein and oil content revealed that the alteration in the average protein and oil content of treated seeds were dose independent. The highest protein and oil content were derived from the dosage of 1500 micromolar and 1200 micromolar, respectively. Furthermore, all fatty acid profiles remained unchanged. Genomic DNAs isolated from the selected phenotypes such as tall, high protein and high oil content showed no significant difference in the m[superscript 5]C content in comparison with DNAs from the control samples. The M[subscript 0] showed tall, short, high protein and high oil content and exhibited the inheritance of such phenotypes in the M[subscript 1] plants.