Scientists at the Australian Centre for Plant Functional Genomics and the University of Adelaide and Cambridge University have developed salt-tolerant plants using a new type of genetic modification. The results could impact food production and security, since salinity affects agriculture worldwide.
Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The sodium toxicity of many crop plants is correlated with over-accumulation of sodium in the shoot. It was previously suggested that the engineering of sodium exclusion from the shoot could be achieved through an alteration of plasma membrane sodium transport processes in the root, if these alterations were cell specific. Current research published in The Plant Cell confirms this. Plants with reduced shoot sodium have increased salinity tolerance. The results demonstrate that the modification of a specific sodium transport process in specific cell types can reduce shoot sodium accumulation, an important component of salinity tolerance of many higher plants.
"Salinity affects the growth of plants worldwide, particularly in irrigated land where one third of the world's food is produced. And it is a problem that is only going to get worse" said team leader Mark Tester, professor at the University of Adelaide.
Tester says his team used the technique to keep salt out of the leaves of a model plant species. The researchers modified genes specifically around the plant's water conducting tissue (xylem) so that salt is removed from the transpiration stream before it gets to the shoot.
"This reduces the amount of toxic salt building up in the shoot and so increases the plant's tolerance to salinity," Tester said.
"In doing this, we've enhanced a process used naturally by plants to minimize the movement of salt to the shoot. We've used genetic modification to amplify the process, helping plants to do what they already do - but to do it much better" he added.
The team is now in the process of transferring this technology to crops such as rice, wheat and barley, said an Adelaide release.
