Figure error forces retraction of transgenic chickpea paper
But one group of scientists made hummus out of their approach when they botched what evidently was a key element of a figure in their 2011 paper in Plant Cell Reports (PCR).
The article, “High-efficiency Agrobacterium-mediated transformation of chickpea (Cicer arietinum L.) and regeneration of insect-resistant transgenic plants,” came from researchers at the National Botanical Research Institute in Lucknow, India. Cited three times, according to Thomson Scientific’s Web of Knowledge, it purported to find that:
To develop an efficient genetic transformation system of chickpea (Cicer arietinum L.), callus derived from mature embryonic axes of variety P-362 was transformed with Agrobacteriumtumefaciens strain LBA4404 harboring p35SGUS-INT plasmid containing the uidA gene encoding β-glucuronidase (GUS) and the nptII gene for kanamycin selection. Various factors affecting transformation efficiency were optimized; as Agrobacterium suspension at OD600 0.3 with 48 h of co-cultivation period at 20°C was found optimal for transforming 10-day-old MEA-derived callus. Inclusion of 200 μM acetosyringone, sonication for 4 s with vacuum infiltration for 6 min improved the number of GUS foci per responding explant from 1.0 to 38.6, as determined by histochemical GUS assay. For introducing the insect-resistant trait into chickpea, binary vector pRD400-cry1Acwas also transformed under optimized conditions and 18 T0 transgenic plants were generated, representing 3.6% transformation frequency. T0 transgenic plants reflected Mendelian inheritance pattern of transgene segregation in T1 progeny. PCR, RT-PCR, and Southern hybridization analysis of T0 and T1 transgenic plants confirmed stable integration of transgenes into the chickpea genome. The expression level of Bt-Cry protein in T0 and T1 transgenic chickpea plants was achieved maximum up to 116 ng mg−1 of soluble protein, which efficiently causes 100% mortality to second instar larvae of Helicoverpa armigera as analyzed by an insect mortality bioassay. Our results demonstrate an efficient and rapid transformation system of chickpea for producing non-chimeric transgenic plants with high frequency. These findings will certainly accelerate the development of chickpea plants with novel traits.
But according to the retraction notice, such certainty was a tad premature:
This article has been retracted on the demand of the authors because of error in one figure panel. Consequently, the data is not unambiguous. All of the authors have agreed with the retraction notice and sincerely regret the inconvenience that this retraction causes to PCR and its readership.