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By Zafrir Rinat
A new study by Israeli scientists may help improve the ability of plants to survive in highly saline soil, one of the main threats to agriculture worldwide.
The study, recently published in the Journal of the American Academy of Sciences, describes a method of genetic engineering that may allow a plant to neutralize excess salt.

In many parts of the world, including the northern Negev and the Jezreel Valley, large amounts of salt remain in the soil after irrigation water evaporates or is used by the plants.

Salt impairs the supply of water to the plant and causes cell toxicity, and in many places irrigation must be increased so water not utilized by the plants will drain the salt that builds up in them.

Professor Alex Levine and doctoral student Yehoram Leshem of Hebrew University's Silverman Institute studied the effects of exposure to salt in the thale cress (Arabidopsis thaliana).

Leshem said this plant is able to get rid of excess salt through a special organ.

However, Leshem says that "oxygen coming from the root of the plant to this organ damages its covering and impairs the plant's ability to deal with exposure to salt.

"The damage is cumulative and the plant dies within a few days," he says.

The research followed the movement of the oxygen until it reaches the covering organ and then manipulates the gene allowing the oxygen to reach the covering and impair its function.

Further testing compared genetically manipulated thale cress sprouts exposed to salt with those that were not manipulated. The former survived a few more days than the latter.

Leshem noted that despite the damage the oxygen does to the organ, it has other functions, and the research is preliminary and must still be tested on crops.


[www.haaretz.com]