Wednesday, 15 June 2011

What do liver cells have in common with wheat seedlings? The University of Western Australia's PhD student Rachel Shingaki-Wells has found that both cope with oxygen starvation better when fed three amino acids: glycine, serine and alanine.

Ms Shingaki-Wells said amino acids were the building blocks of proteins, the large molecules that carry out functions in the cell and her research, published in the leading international plant journal Plant Physiology , has led to better understanding of how to maintain the seedling health of wheat when floods become a threat.

"Most crop plants are devastated during floods because they can't get enough oxygen and they start to drown," Ms Shingaki-Wells said.  "In animals, a lack of oxygen is likely to result in death after only a few minutes. Remarkably, some plants can survive for weeks without oxygen."

Due to its long cultivation under water, rice has adapted to become the most flood-tolerant crop in the world.

"At a molecular level, we've seen a lot of changes going on in rice plants during flooding, including significant increases in the production of serine, glycine and alanine and the molecules used to make these amino acids," Ms Shingaki-Wells said.

"Rice is very busy trying to survive.  Unfortunately the same cannot be said for wheat; its response is slower and if oxygen doesn't return swiftly, it's likely to die.  When I reviewed medical research online, I found that when liver cells were given these same three amino acids, they were better able to cope with oxygen deprivation."

Armed with this information, Ms Shingaki-Wells set out to recreate the effect in wheat and it worked.  Wheat seedlings had lower tissue damage when fed with these amino acids.

"What was particularly intriguing was that when rice was fed these amino acids, nothing happened.  It seems that rice's biology is set up to respond to flooding and doesn't need our help.  Wheat is another story; it could do with some outside help," Ms Shingaki-Wells said.

"I hope this discovery can have positive impacts on our understanding of how to decrease the losses of all types of crops during natural disasters, like flooding.  It was also very satisfying to take information from the world of mammalian research and apply this successfully to plant research."

Ms Shingaki-Wells' supervisor, Winthrop Professor Harvey Millar, from the ARC Centre of Excellence in Plant Energy Biology , said finding out how plants worked on a molecular level was very important.

"This information can provide a new target for plant breeders, as they work to improve the tolerance of wheat plants to everything that the weather throws at them.  That's why the Grains Research Development Corporation (GRDC) provides funding for this type of research."

Media references

Winthrop Professor Harvey Millar (+61 8)  6488 7245  /  (+61 4) 20 308 534
( ARC Centre of Excellence in Plant Energy Biology )
Aleta Johnston (UWA Public Affairs)  (+61 8)  6488 7797  /  (+61 4) 31 514 677


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