We would like to bring to your attention the issues we have just uncovered relating to the data presented in the paper ‘Down-regulation of glucan, water-dikinase activity in wheat endosperm increases vegetative biomass and yield’ Volume 10, Issue 7, pages 871–882, September 2012.
The issues uncovered do not negate the central conclusions of the paper but do make a material difference to the way in which the data should be presented.
In brief, having access to the 9k SNP chip has revealed that the Bobwhite 26 (bw26) control used in the experiments was not the same genotype as the line transformed. Of about 5469 markers scored, 37.4% were not the expected genotype compared with an authentic bw26 control.
At the time of the transformations, morphology and HWM glutenins suggested the transformed genotype was authentic bw26. Therefore, pertinent comparisons can only be made between the negative segregants and the transgenic lines and not between the transgenic lines and the untransformed line used in these studies. Further to this, the SNP genotyping has shown that the negative segregant used in the reported field trials was an admixture of the negative segregant and the line that was presumed to be the untransformed control; thus, data presented for the field trials must now be disregarded.
Therefore, the following amendments are required:
- Disregard bw26 from Figures 1c and d, 3 and 4 as it is no longer an appropriate comparator
- Disregard bw26 from supplemental material Tables S1, S2 and S4.
- Figure 1 of the original manuscript uses an incorrect control. We have now repeated the entire experiment and the attached figure should be considered in lieu of the original Figure 1. All the original conclusions drawn regarding the results in Figure 1 remain valid.
- Disregard Figure 5, Figure S3 and Table S3 as the genotyping has suggested that the negative segregant used was an admixture of the negative and bw26, and thus, the comparison is not valid.
- Disregard bw26 in Table 1. As a consequence, page 873 in the ‘Results, Enhanced biomass production and yield in GWD RNAi plants’ section, first paragraph,
Read ‘28 and 68% compare to the negative segregant’ instead of ‘58 and 81% compare to the parent line’.
Read ‘17–50% and 7–54%’ instead of ‘20–54% and 16–69%’.
Page 873, in the ‘Results, Enhanced biomass production and yield in GWD RNAi plants’ section, second paragraph, read ‘21–60%’ and ‘17–50%’ in lieu of ‘40–62%’ and ‘30–54%’, respectively.
Page 875, in the ‘Results, Enhanced biomass production and yield in GWD RNAi plants’ section, first paragraph,
Read ‘12–19%’ instead of ‘5–10%’.
Read ‘6% (taGWD4-7), 18% (taGWD4-6) and 21% (taGWD1-1)’ instead of ‘14% (taGWD4-7), 27% (taGWD4-6) and 29% (taGWD1-1)’.
Read ‘yield advantage of 18%’ instead of ‘yield advantage of 26.6%’.
As no negative segregant was included in the experiment reported in Table 2, no valid conclusions can now be drawn and the data presented should be disregarded. In the light of this, we have repeated some basic measurements that demonstrated higher sugar content in stems of the transgenic lines during grain filling, compared to negative segregants. However, we have not yet reproduced the entire experiment presented in the manuscript.
As the genotyping has suggested that the negative segregant used was an admixture of the negative and BW26, please disregard all results and discussion regarding the field trials page 875 and the Discussion, ‘Grain-specific down-regulation of GWD increases biomass and yield in subsequent generation’ section page 878.
With the best regards,
Dr Jean-Philippe Ral