The Centre has hiked the Minimum Export Price (MEP) of onion by 175 dollar per tonne to 425 dollar per tonne to ensure adequate supply in the domestic market and contain price rise of the commodity.According to a notification issued yesterday by the Directorate General of Foreign Trade the MEP for export of all varieties of onions will be 425 dollar per tonne.The new rate will be applicable with immediate effect.MEP is the rate below which no exports are allowed.