Functional Analysis Of OsVDAC During Rice Grain-filling

Voltage-Dependent Anion Channels (VDAC) are the main transport protein on themembrane which play vital roles in the energy metabolism, cell apoptosis, substancetransportation and signal transduction pathways. The previous studies identified by differentialproteomics suggested that VDAC protein can mediate the signal transduction of ABA in rice grainwhich closely related to the grain development processes, however the molecular mechanisms ofgrain-filling mediated by it are still unknown. The OsVDAC functions in the rice grain-fillingneeds to be deeply analyzed, in turn to clear the protein–protein interaction network of ABAregulation mediated by OsVDAC in grain-filling, which have important significances forrevealing the molecular mechanism of grain-filling.Obtaining OsVDAC interacting protein and constructing OsVDAC protein interaction,networks were conducted to clarify its function in the grain-filling using protein-proteininteraction technology. Cloning the Os vdac gene firstly and then inducing the expression ofOsVDAC fusion protein, in turn to obtain OsVDAC polyclonal antibody from immuned mice,then OsVDAC interaction proteins were fished by co-immunoprecipitation(Co-Ip). Meanwhile,OsVDAC interaction proteins were acquired by GST pull down.28interaction proteins wereobtained by CO-IP and GST pull down. It was suggested that ABA regulation inducedaminoacyl-tRNA synthetase and potassium channel AKT3firstly and they performed some rolesafter interacting with VDAC. Later on, VDAC regulated the starch synthesis through interactingwith carbohydrate metabolism associated proteins(1,4-alpha-glucan branching enzyme, sorbitoldehydrogenase, utp-glucose-1-phosphate uridylyltransferase, glycoside hydrolase), glycolisisassociated proteins(glyceraldehyde-3-phosphate dehydrogenase), ATP transport associatedproteins(ATP binding protein, alpha tubulin) and starch synthesis associated proteins(starchbranching enzyme,Sucrose synthase,ADP-glucose pyrophosphorylase,plastidial starch phosphorylase1). In addition, VDAC was also interacted with protein metabolism,nucleic acid metabolism, growth&development and defense associated proteins, in turn to affectthe grain-filling plumpness. It was visible that OsVDAC played significant roles in thegrain-filling. which also had important roles in sensing the ABA regulation in the grain-filling.