Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor
Authors: Yan Liu
Cigang Yu
Shanshan Dong
Zhenhua Zhang
Ming Chen
Changyong Wang
Journal: PLoS ONE (2016)
Discipline: Multidisciplinary
Keywords: Pollen-mediated gene flow; Transgenic wheat; Pollen dispersal; Gene flow frequency; Transgene escape
Affiliations: Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China., Key Laboratory on Biosafety of Environmental Protection, Ministry of Environmental Protection, Nanjing, China., Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.

Abstract:  Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow. 

Retracted: Yes

PubPeer comments:
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 Retracted [9 March 2022] . --------------- Following the publication of this article [1], concerns were raised regarding the results presented in Fig 2. Specifically, repetitive patterns were identified in the background of lanes 2u20139. This concern was discussed with the first author and corresponding author, and raw image data underlying the figure in question were requested. The authors commented that the similar areas in the background of Fig 2 may have been the result of image editing errors. The authors stated that the raw image data underlying the published figure is no longer available. They provided alternative image data which was described as PCR detection of the Nib8 transgene in seedling samples. However, in the absence of the original data supporting the published figure, the journal does not consider that alternative experiment data are sufficient to resolve the image concerns. In addition, the Data Availability statement for this article reads u201cAll relevant data are within the paper and its Supporting Information files.u201d As the raw image data underlying Fig 2 are not available, the article does not comply with PLOS ONEu2019s Data Availability policy that was in place at the time of the articleu2019s submission. In the absence of the raw data, the concerns regarding the integrity of the image data in Fig 2 remain unresolved. Therefore, the PLOS ONE Editors retract this article. SD agreed with the retraction. YL, CY, ZZ, MC and CW either did not respond directly or could not be reached. , 
 The journal was notified of this concern via email on August 4, 2019. ,