Plant vacuoles have multifaceted roles including turgor maintenance,
cytosolic pH and ionic homeostasis, plant protection against
environmental stress, detoxification, pigmentation, and cellular
signaling. These roles are achieved through the coordinated activities
of many proteins in the tonoplast (vacuolar membrane), of which the
proton pumps and ion transporters have been modified for improved
abiotic stress tolerance in transgenic plants. Here we describe a method
to manipulate vacuolar H+ -pyrophosphatase in turfgrass and
evaluate the impact of the modified tonoplast on the phenotype,
biochemistry, and physiology of the transgenics. Creeping bentgrass (Agrostis stolonifera L.) plants overexpressing an Arabidopsis vacuolar H+
-pyrophosphatase AVP1 exhibited improved growth and enhanced salt
tolerance, likely associated with increased photosynthesis, relative
water content, proline production, and Na+ uptake. These transgenic plants also had decreased solute leakage in the leaf tissues and increased concentrations of Na+ , K+ , Cl?
, and total phosphorus in the root tissues. Similar strategies can be
employed to manipulate other tonoplast transporters and in other plant
species to produce transgenic plants with improved performance under
various abiotic stresses.