Why do plants lack sodium pumps and would they benefit from having one?

The purpose of this minireview is to discuss the feasibility of creating a new generation of salt-tolerant plants that express Na+/K+-ATPases from animals or green algae. Attempts to generate salt-tolerant plants have focussed on increase the expression of or introducing salt stress-related genes from plants, bryophytes and yeast. Even though these approaches have resulted in plants with increased salt tolerance, plant growth is decreased under salt stress and often also under normal growth conditions. New strategies to increase salt tolerance are therefore needed. Theoretically, plants transformed with an animal-type Na+/K+-ATPase should not only display a high degree of salt tolerance but should also reduce the stress response exhibited by the first generation of salt-tolerant plants under both normal and salt stress conditions. The biological feasibility of such a strategy of producing transgenic plants that display improved growth on saline soil but are indistinguishable from wild-type plants under normal growth conditions, is discussed.