Posted 4-3-00

Here are a few quick examples, compliments of ARS plant physiologists Catherine Grieve and Don Ort: stunted, or slower growth; "sick" leaves (a condition called necrosis); smaller yield (meaning the bean plant produces fewer seeds that can be harvested as our food); roots that "drink up" less water; and wasted energy--the result of getting rid of salt in plant tissues.

Here's a more detailed explanation: Plants that can't stand very salty soils are called "glycophytes" (gleye-coe fights). These include bean plants. Lots of salt creates two problems for them. First off, a glycophyte plant can't take in water from a source, like seawater, that has more salt than its own sap, or juices. If the plant does, it'll die. That's because the salty seawater actually removes water already stored in the plant. So in a sense, the plant dies of thirst! Second, salt contains sodium. Too much sodium can poison the bean plant. It also prevents the plant from taking up important minerals like potassium, which is needed for growth.

Some plants don't mind lots of salt, though. They're called "halophytes" (hey-loe fights). You probably know of some. One example is the mangrove tree, which dips its roots into seawater in coastal areas. Another is the coconut tree, which also grows along the beach.

By studying halophyte plants, scientists hope to breed new crop varieties that will grow well in salty conditions that would normally harm them. That's especially important as the world's population grows and choice cropland becomes less available for farming.

-- Sci4Kids Staff, Catherine Grieve, U.S. Salinity Lab, Riverside, California; Don Ort, Photosynthesis Research Lab, Urbana, Illinois.

Back to Archives/ Go home instead