New Worlds: Research produces more salt-tolerant plants

Plants aren't crazy about being irrigated with salt water, but some will tolerate it.

By JUDY SIEGEL-ITZKOVICH
dead sea 298 (photo credit: )
dead sea 298
(photo credit: )
Plants aren't crazy about being irrigated with salt water, but some will tolerate it. Now a technique for increasing their tolerance and thus preventing stunted growth and even death has been developed at The Hebrew University of Jerusalem. The method has much potential for dealing with soil salinization in different regions of the world, including Israel, according to Prof. Alex Levine and doctoral student Yehoram Leshem of the department of plant and environmental sciences at the Alexander Silberman Institute of Life Sciences The problem is exacerbated by intense agriculture and irrigation. Salinity drives the plant into water deficit and is accompanied by toxicity of sodium and chloride ions, resulting in restricted growth and reduced yield. Moreover, salt stress causes a secondary oxidative stress, sometimes resulting in plant death. Through detailed lab studies, they were able to achieve a new understanding of the mechanisms by which plants deal with salty conditions. Based on this knowledge, and through genetic manipulation, Levine and Leshem were successful in reducing the self-induced membrane damage that takes place under stressful conditions. The altered plants were also shown to have greater salt tolerance. The work by Levine and Leshem - published in the Proceedings of the [US] National Academy of Sciences - has not only opened new insights into plant responses to salt stress, but also points the way to new ways of improving salt tolerance in a broad spectrum of crops. It can thus bring great economic and social benefit to many nations. LASERS MONITOR DEAD SEA SINKHOLES The increasing number of sinkholes - gaping holes that open up around the Dead Sea due to the reduction of its water level - is worrying geologists and other scientists. Although there is no agreement on how to prevent their occurrence, scientists from the Technion-Israel Institute of Technology and the Israel Geological Institute have developed a model for automatically identifying sinkholes and predicting where they will spread. Dr. Hagai Pilin, a member of the mapping and geoinformation team at the Technion's civil engineering faculty, says sinkholes are just one of many phenomena caused by the drop in the Dead Sea's surface by a meter per decade. But it is important to predict where they will appear because of the damage they can cause. The team performed laser scans from the air using a system that produces 3-D images in a "cloud of dots." The laser can penetrate plant matter and supply data without human intervention, monitoring changes in the surface that lead to the formation of sinkholes. Fully 97% of the sinkholes, some less than a meter wide, were identified. Knowing where the sinkholes will spread is important when planning roads, homes, hotels and other infrastructure. ARCHEOLOGY PAPER IN TOP SIX Bar-Ilan University Prof. Mordechai Kislev's research on the fig was recognized as being "among the six most important archeological discoveries in 2006" by Discovery magazine. Kislev, of the Ramat Gan university's archeological botanics lab, and colleagues discovered evidence that humans domesticated plants 1,000 years earlier than had been thought. They published evidence in Scienceof the oldest-known domesticated plants - figs - at Gilgal in the Jordan River valley. The figs without fertile seeds found in Gilgal are the oldest domesticated plant ever found - evidence that Israel contributed significantly to the development, and perhaps even to the beginnings, of agriculture. The article provided additional insight into the Agricultural Revolution, with the authors noting that humans apparently already knew how to plant choice trees at the beginning of the Neolithic period (which ended 7,500 years ago) and thus were able to increase their yield. FIRED UP BY GIVING It is better to give than to receive, says the well-known axiom. Now American researchers have found that donating to charity stimulates areas of the brain connected to the pleasure of eating a favorite food. The journal Science recently published a study using brain scans that bolstered the idea that altruism is a human characteristic. University of Oregon scientists studied the neural responses in 19 volunteers who made various transactions on a computer. The results showed that nerve cells in the caudate nucleus fire when money is "donated" to a food charity; the identical nerve cells fire when the person ate some favorite treat. Amazingly, the same neural activity showed up when taxes were paid, although not to the same extent. MEOW! Domesticated cats originated not in Egypt but in the Fertile Crescent of the Middle East, according to research published in Science. "This was much earlier than Egyptian civilization," said Carlos Driscoll, lead author of the study and a University of Oxford graduate student. The team took genetic samples from 979 cats, including felines exhibited at cat shows, feral cats and wildcats trapped in Mongolia and Kazakhstan. They were then divided into six categories that included 36 DNA markers. The result was that house cats fell into the same group as Fertile Crescent wildcats. The genome of wildcat populations is being "diluted" with DNA from house cats, and thus threatening the wildcats' survival, according to the International Society for Endangered Cats.