Scientists explain how salt impedes plant growth

Scientists at the Carnegie Institution discovered that not all roots of plants are equally inhibited by salt. In their paper published in the current issue of The Plant Cell, they reported that an inner layer of tissue in the branching roots is sensitive to salt, which activates abscisic acid, a stress hormone that impedes growth.

The researchers grew Arabidopsis plants and used a custom imaging system to measure the response of the plants to salt. Through this technique, they found that the branching roots went dormant when exposed to salt and that abscisic acid was the key signaling molecule. To understand the action of abscisic acid in blocking plant growth, they developed mutants and suppressed the function of the hormone in different root layers. The results showed that aside from acting as a filter, the epidermis or the inner layer of the root also works like a guard, with abscisic acid, preventing the plant from growing in dangerous environments. The findings will help other scientists develop plant varieties that can grow in saline soils.

Read more about the study at http://carnegiescience.edu/news/breakthrough_how_salt_stops_plant_growth.