4th Dec 2014

GARNet Advisory Committee Chair Professor David E Salt (University of Aberdeen) has led a team that identified one of the genes that allows some plants to pump poison out of roots. This discovery could pave the way for a new generation of crops which do not absorb high levels of the poison arsenic.

The research team includes scientists from the Shanghai Institutes for Biological Sciences of the Chinese Academy of Sciences, Nanjing Agricultural University and Rothamsted Research, which receives strategic funding from BBSRC. The team found that the gene HAC1 is used by Arabidopsis thaliana to control arsenic accumulation and that when it is removed, the concentration of arsenic in the plants increased 300-fold. Identification of this key gene in A. thaliana makes it simpler to identify the equivalent gene in food crops such as rice and wheat.

Professor David E Salt said: "In order to survive, the plants need to find a way to deal with the poison entering their roots and so they convert it from arsenate, the form in which it is absorbed, to arsenite which can then be effluxed or pumped out from the roots. Previous research has identified that this process was happening but not how it was happening and that is where we have taken an important step forward.

"Now we know the identity of the gene we can use this information to breed new varieties of crops with a strong version of the arsenate reductase but which also keep their favourable agronomic properties. Putting this into practice would mean you have a good crop without arsenic."

Professor Fangjie Zhao, whose team at Rothamsted Research and Nanjing Agricultural University contributed to the characterization of HAC1 gene function, said: "Arsenic contamination is a serious problem worldwide. Recent surveys show that substantial proportions of cereals exceed new EU limits for arsenic. One way to tackle this problem is to breed crop varieties low in the accumulation of arsenic. The discovery that HAC1 plays a crucial role in limiting arsenic accumulation should help to achieve this goal. This new knowledge also fits an important piece of jigsaw into the overall picture of how plants deal with a toxin that is widely present in the soil."

Publication: Genome-wide association mapping identifies a new arsenate reductase 2 enzyme critical for limiting arsenic accumulation in plants. (2014) PLOS Biology doi: 10.1371/journal.pbio.1002009

This article is adapted from this press release from BBSRC.