A Functional Research Of The Red Rice Heme-Binding Protein OsHBP2 From The SOUL Family

As a medicinal and edible food crop,red rice has received widespread attention for its high nutritional value.At present,with the development of economy and society,it is of great significance to use modern biotechnology to conduct in-depth research and explore the beneficial nutrition and health factors in red rice.Protein is an extremely important supporting factor for life activities,providing nutrients and participating in the regulation of cell activity.Heme is a class of small molecules containing pyrrole rings,which have important functions such as resisting oxidative stress and energy transformation in human,animal and plant cells.Moreover,its own metabolism is regulated by a series of related proteins or enzymes.Using molecular cloning,gene expression analysis,in vitro protein activity detection,model animal and plant oxidative stress treatment and other research methods and technologies,this paper systematically studied the molecular function of the SOUL family heme-binding protein OsHBP2 in red rice,and obtained the following research results:1.The gene encoding heme-binding protein OsHBP2 in red rice was successfully cloned.The full-length nucleotide sequence of the OsHBP2 gene coding frame nucleic acid is 651 bp,and it pre-encodes a protein molecule with a molecular weight of 23.5 k Da.Analysis shows that its amino acid sequence contains at least 9 methionine residues,which are likely to endow the protein with special functions.2.The E.coli expression engineering strain of the heme-binding protein OsHBP2 was successfully established to achieve efficient and large-scale in vitro expression of the target protein.The protein was isolated and purified,and it was found that OsHBP2 protein binds the function of heme molecule and scavenging activity of hydroxyl radicals;and can resist oxidation.3.The heme-binding protein OsHBP2 gene has differential expression in red rice tissues and organs,and the expression level is relatively high in roots and leaves,but low in roots;Arabidopsis plants overexpressing OsHBP2 are resistant to hydrogen peroxide oxidation significantly enhanced.4.OsHBP2 protein fed C.elegans,compared with the control nematodes,the wild-type nematodes increased their body length;their motility and reproductive ability(significantly)improved;their resistance to heat stress,ultraviolet stress,and hydrogen peroxide stress(significantly)improved;Some nematode mutants,such as corresponding growth and stress indicators,were significantly altered compared to controls.In conclusion,the study found that the red rice SOUL family heme-binding protein OsHBP2 has the basic properties of binding heme,and also has the function of resisting oxidative stress.At the same time,the successful establishment of an engineered Escherichia coli strain with high expression of the heme-binding protein OsHBP2 in vitro provides an important foundation for further promoting the potential value application of this protein.