Molecular Cloning of Vacuolar H+-ATPase A Subunit Paralogs and their Expression in Pear Fruit

We cloned two cDNAs (PcVHA-A1, PcVHA-A2) encoding V-ATPase A subunit (catalytic subunit) in pear (Pyrus communis L. var. sativa DC, ‘La France’). They encode proteins with a calculated molecular weight of approximately 69 kDa, which consist of 623 amino acids. The expression of PcVHA-A1 mRNA was extremely high in mature fruit and young leaves, but low in flower, young fruit, mature leaves, and root, it increased with the maturation of pear fruit. On the other hand, the expression of PcVHA-A2 mRNA was relatively high at the early and late developmental stages of the pear fruit. A certain level of PcVHA-A2 expression was also observed in flowers and leaves.