Plays redundant role with PV42a in regulating male gametogenesis and pollen tube guidance. Expressed highly in rosette leaves, cauline leaves, open flowers, developing siliques and dry seeds, but at a low level in stems and floral buds. No visible phenotype; probably due to a complementation by PV42b. Shorter siliques and reduced seed sets in pv42a and pv42b RNAi double mutant. Belongs to the 5'-AMP-activated protein kinase gamma subunit family.