Nature to retract plant study

A highly cited __Nature__ paper that identified a long-sought receptor critical for mediating plant response to stress is being retracted after researchers were unable to reproduce the results. Corresponding author on the paper, linkurl:Robert Hill;http://home.cc.umanitoba.ca/~rhill/ from the University of Manitoba, first discovered a problem with the results over the summer when one of his students failed to reproduce the findings. "The binding assay procedures, at least in our hands, did not give the correct results," said Hill. Hill and his coauthors were the first to identify a receptor for abscicic acid (ABA), which regulates plant stress response. Researchers have been trying to identify an ABA receptor for decades -- a finding that would be of major interest to the agriculture industry. In the linkurl:study,;http://www.nature.com/nature/journal/v439/n7074/abs/nature04373.html published in 2006 and cited more 120 times, first author Fawzi Razem, who conducted the work as a postdoc in Hill's lab, found that FCA, a nuclear protein that binds RNA and is involved in plant flowering, also acted as a receptor for ABA. Two more ABA receptors were found in linkurl:2006;http://www.nature.com/nature/journal/v443/n7113/abs/nature05176.html and linkurl:2007;http://www.sciencemag.org/cgi/content/full/315/5819/1712 by other groups who used the same method. Researchers in the field were surprised when the finding was published in early 2006. "That paper was perplexing," said linkurl:Sean Cutler;http://cutlerlab.blogspot.com/ a plant biologist at the University of California, Riverside. "Every paper that's come out claiming to be an ABA receptor has been perplexing." The reason for the hesitation, said linkurl:Peter McCourt,;http://www.ratemyprofessors.com/ShowRatings.jsp?tid=486497 a plant geneticist from the University of Toronto, was that researchers have long known that concentrations of the ABA hormone "goes through the roof" -- increasing about 100-fold -- when plants are stressed. According to Razem's paper, however, FCA binds abscisic acid with a high affinity, meaning that fairly low concentrations of the hormone would trigger a stress response. "Corn plants are always stressed, so by definition the receptor will always be on," said McCourt, "and that doesn't make sense." "I [had] always been very skeptical of binding assays in whole plants," said McCourt. "I read the [Razem] paper and I thought, 'maybe I was wrong.'" In a study to be published in __Nature__, the proofs of which were obtained by __The Scientist__, corresponding author linkurl:Catherine Day;http://biochem.otago.ac.nz/staff/day/cday.html and colleagues from the University of Otago in New Zealand report that they were unable to reproduce the Razem results. They suggest that the sensitivity of the binding assay used by Razem, as well as the authors of the subsequent two ABA papers, was too high, bringing all three into question. A note in that paper states that the Razem paper has been retracted, but since it has not yet been published, the study contains no dates. In an email to __The Scientist__, Day said she had nothing more to add about the Razem study. Peter McVetty,head of the university's plant science department, told the linkurl:Winnipeg Free Press;http://www.canada.com/topics/news/national/story.html?id=1028551 that a calculation error may have "crept in" to the data. The retraction letter for the Razem paper, which Hill coauthored, will be published in the December 11th issue of __Nature__, according to Manitoba University spokesperson John Danakas. __Nature__ declined to confirm the retraction or say when it would be published. Hill said he corresponded with Razem in regards to the retraction, but declined to say what they discussed. Razem could not be reached for comment by phone or email. According to Danakas, Razem, who became an assistant professor at the University of Manitoba shortly after the publication of this study (September of 2006), has resigned from his position, effective by the end of this year. Danakas said Razem is leaving for another appointment, but where is "not known to us." Danakas also said he could not comment whether an investigation was currently underway, but did say that in cases where scientific findings are not reproducible the university usually performs a "thorough and rigorous investigation" into possible fraud allegations. "It obviously put a big dent in what we're doing," said Hill. "It's meant that we've had to go back and reinterpret data." One graduate student has had to "chop a publication" which was based on the assumption that the ABA receptor was real. "I've come to reconcile with the problem," said Hill, adding that he is working to correct it "without hurting too many people." "All one can do it be upfront about it, once one gets in a situation" like this, said Hill. **__Related stories:__*** linkurl:The drought receptor;http://www.the-scientist.com/article/display/54050/ [Jan 2008]*linkurl:Science retracts major Arabidopsis paper;http://www.the-scientist.com/news/display/53081/ [20th April 2007]*linkurl:US postdoc fabricates DNA data;http://www.the-scientist.com/blog/display/54637/ [9th May 2008]

Nature to retract plant study

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