16 July 2009

Genetically produced salt-free crops

Salt-tolerant cereal crops are a step closer to reality as a new type of genetic modification (GM) process is now under development.

Based at the University of Adelaide’s Waite Campus in Australia, the research team used a new GM technique to contain salt in parts of the plant where it does less damage.

Genetically modified plants and non-genetically modified plants grown in saline conditions. Non-GM plants, above, struggle to grow in saline conditions; GM plants, below, thrive in the same conditions.  Source: Australian Centre for Plant Functional Genomics

Salinity affects agriculture worldwide, which means the results of this research could have a positive impact on world food production and security.

“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, as pressure to use less water increases and quality of water decreases,” said the team’s leader, Professor Mark Tester, from the School of Agriculture, Food and Wine at the University of Adelaide and the Australian Centre for Plant Functional Genomics.

“Helping plants to withstand this salty onslaught will have a significant impact on world food production.”

Tester’s team used the technique to keep salt—as sodium ions (Na+)—out of the leaves of a model plant species. The researchers modified genes specifically around the plant’s water conducting pipes (xylem) so salt exits the transpiration stream before it gets to the shoot.

“This reduces the amount of toxic Na+ 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 Na+ 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.”

The team is now in the process of transferring this technology to crops such as rice, wheat, and barley.

“Our results in rice already look very promising,” Tester said.

For related information, go to www.isa.org/environment.