Cabbage batch skids: new experiments dry up plant paper

Prominent plant researcher Mark Estelle has retracted a paper on plant hormones after follow-up studies showed the conclusions were incorrect.

The hormone in question, auxin, is a major player in plant growth and development. The retracted Current Biology paper reported that a certain auxin receptor, designated AFB4, downregulates the responses of cabbage-cousin Arabidopsis thaliana to the signaling molecule. But after publication, the researchers experimented with a mutant seedling that didn’t produce the receptor, and discovered it didn’t overreact to auxin signals, indicating the receptor wasn’t playing a major role in limiting the effects.

Estelle, a Howard Hughes Medical Institute investigator based at the University of California, San Diego, told us he and his team are working on a paper that will contain the accurate data from the paper, along with new findings.

Here’s the notice for “The AFB4 Auxin Receptor Is a Negative Regulator of Auxin Signaling in Seedlings”, which has 62 citations, per Google Scholar:

(Current Biology 21, 520–525; March 22, 2011) In this article, we reported that the AFB4 protein is a negative regulator of auxin response based on the auxin hypersensitivity of the afb4-2 mutant line. Recently we obtained a second afb4 allele and confirmed that it is an RNA null. This mutant is not auxin hypersensitive, indicating that our conclusion that AFB4 is a negative regulator of auxin response is incorrect. For this reason, we wish to retract the article. Other conclusions from the study, including the demonstration that AFB4 and AFB5 are auxin receptors and are the major targets of the synthetic auxin picloram, remain valid. The corresponding author wishes to apologize to the scientific community for any confusion that might have arisen from the study.

Estelle emailed us with more details:

As we state in the notice, when we analyzed a new loss of function allele of the AFB4 gene, we discovered that it did not have the phenotype exhibited by the afb4-2 allele, indicating that our conclusion concerning the function of AFB4 was incorrect. Yes, we are currently working on a manuscript that will include some of the data in the retracted paper, as well as additional data.

We’ve reached out to the journal editor, and will update if we hear back.

Hat tip Rolf Degen and JATdS

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