PARIS--New findings appear to confirm suspicions that several important papers in a hot area of plant biology were fatally compromised by scientific fraud. The results, published in the March issue of Plant Journal, stem from an investigation at the Max Planck Institute for Plant Breeding Research in Cologne, Germany, which concluded last year that a laboratory technician had falsified some experiments.
In the Plant Journal article, a team of researchers at the Cologne institute, along with colleagues from other European labs, report that they could not reproduce key findings in eight papers published in Science, EMBO Journal, the Proceedings of the National Academy of Sciences (PNAS), Trends in Plant Science, and Plant Journal, dating back to 1992. Two other papers from the institute, which had originally appeared in Nature and PNAS in 1997, were retracted last year by most of their authors after their findings also could not be reproduced. "I can no longer believe any parts of the data in any parts of the papers," says plant biologist Alan Jones of the University of North Carolina, Chapel Hill. "Major conclusions were drawn" from the papers, he says.
The affair dates from the early 1990s, when Richard Walden and other researchers at the institute pioneered a new way to cause plants to "overexpress" particular genes--cause the genes to produce much higher levels of proteins than normal. Walden and his co-workers used this technique to study two plant hormones, auxin and cytokinin, that control plant cell division and growth. The team produced numerous mutants of tobacco plants that they thought were capable of growing independently of the presence of these two hormones. Using these mutants, the team isolated a number of genes, proteins, and other factors that appeared to be involved in the hormones' mechanism of action.
It now appears, however, that these mutants were not capable of hormone-independent growth after all. The investigation carried out at the institute last year concluded that a technician added plant growth factors to culture media used in the experiments and manipulated the experiments to make it appear that cultured plant cells were capable of auxin- and cytokinin-independent cell division. The new results suggest that this compromised the papers' central findings. The lead author of the Plant Journal report, plant researcher Jeff Schell--who is head of the department in which the Walden group worked and was a co-author on the disputed papers--agrees that all the major findings were "subject to falsification."