Tuesday, 22 May 2012

Salt Tolerant Wheat by Michael Timothy Cross

Blog Post Assignment
Salt-Tolerant Wheat

Have a geeb at the original site at:

                Salinity is a major problem facing Australian and worldwide wheat farmers today.  However, with the combined work of the CSIRO, NSW Department of Primary Industries, University of Adelaide, the Australian Centre for Plant Functional Genomics and the ARC Centre of Excellence in Plant Energy Biology, this may not be such a prevalent problem in the future.
                Scientists from these centres tested upon durum wheat (Triticum turgidum ssp. durum), which is commonly used in making pasta. Durum wheat has a low threshold for salinity levels in the arable soil, but with the use of cross breeding, significant improvements were made in the wheat productivity. This was done by experimenting with an ancestral wheat relative known as Triticum monococcum.
                Durum wheat has been hybridised in the past, but unfortunately the genes that result in salt tolerance was left out. This lack of salt tolerance is known as a low Na+ exclusion. With further study of Triticum monococcu, the scientists were able to discover the gene (TmHKT1;5-A) which resulted in the higher salt tolerance. This particular gene, which is located on the plasma membrane of the xylem cells in the roots, has a pivotal role in removing the sodium from the roots of the plant. This allows much lower salt content in the leaves.  This gene was then cross-bred, traditionally, with the durum wheat.
                This particular experiment also has field testing in farms across NSW and Australia, not just in the lab. These scientists began to test their experiments in the field and discovered that the genetically modified durum wheat had a substantial increase in yield than the control. In arable soil with low salinity, the durum wheat and the modified wheat had similar results. However, in the test with higher salinity content in the salt, the modified wheat had a yield of up to 25% greater than the non-modified durum wheat. Dr. Rana Munns of the CSIRO Plant Industry said “This work is significant as salinity already affects over 20% of the world’s agricultural soils, and salinity poses an increasing threat to food production due to climate change.”
                The researchers used molecular techniques to discover and identify this unique gene in Triticum monococcum; however, because of the use of traditional cross-breeding this plant has not been classified as transgenic or genetically modified. This allows this plant to be established without any restrictions which is usually the case.
                With field and test results looking so positive in this particular case, this gene, TmHKT1;5-A , will soon be issued into other wheat varieties including bread wheat. It is hoped that similar results will be recorded in the field like the durum wheat. This is very important, as arable land is extremely finite and with the world’s population expected to rise exponentially and climate change having a greater effect, the demand for food will become a lot larger.

Dean, T, 2012, Salt tolerant wheat could boost yields by 25%, viewed 16 March 2012 <http://www.lifescientist.com.au/article/418188/salt_tolerant_wheat_could_boost_yields_by_25_/>
University of Adelaide 2012, Researchers report breakthrough on salt-tolerant durum wheat, viewed 16 March 2012<http://www.physorg.com/news/2012-03-breakthrough-salt-tolerant-durum-wheat.html >
Nano Technology 2012, Wheat grain yield on saline soils is improved by an ancestral Na+ transporter gene, viewed 16 March 2012, <http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.2120.html#/ref3

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