A method for enhancing various economically important yield-related traits in plants by modulating expression in a plant of a nucleic acid encoding a PMP (protein of interest) polypeptide. Plants having modulated expression of a nucleic acid encoding a PMP polypeptide, which plants have one or more enhanced yield-related traits compared with control plants are provided. Unknown PMP-encoding nucleic acids and constructs comprising the same, which is useful in performing the methods of the invention, are also provided.