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one-third of the irrigated land on earth is not suitable for growing crops
because it is contaminated with high levels of salt. More farmable land
is lost through high salt levels in soil than is gained through the clearing
of forest resources.
Most plants are highly sensitive to salty conditions, which
cause stress and significant biochemical change due to absorption and
influx of sodium from the salty soil.
However, NSF-funded scientists are studying approaches that will lead
to plants that can tolerate salty growing conditions. In recent years,
it has become clear that cells of higher plants are capable of adjusting
to high levels of salt. In fact, if exposed in a gradual manner, plants
can grow and reproduce during exposure to very high concentrations of
"Turning on" processes
distinguishes salt-tolerant species from susceptible plants is the ability
to use or "turn on" this process when necessary.By
understanding the signaling system that allows a plant to sense excess
sodium in the environment and then make necessary adjustments, plant
biologists will be able to influence the growth of crop plants in arid
and inhospitable conditions.
Work at the University of Arizona and other university labs is under way
to identify what determines or causes salt tolerance in plants. This research
has led to the identification of a location in the plant genetic code
necessary for salt tolerance.