Journal or Publishing Institution: New Phytologist
Study: http://onlinelibrary.wiley.com/doi/10.1111/nph.12748/full
Author(s): Lu, B.R., Snow, A.A., Yang, X. and Wang, W.
Article Type: Journal Publication
Record ID: 1461
Text: Grunewald & Bury (2014; in this issue of New Phytologist, pp. 367–369) criticize our recent peer‐reviewed paper (Wang et al., 2014; in this issue of New Phytologist, pp. 679–683), stating that we ‘unnecessarily harm the sensitive debate on GM crops.’ We will not focus on this politically charged topic here, but we do want to address scientific questions about our study of transgenic crop–weed (Oryza sativa and O. sativa f. spontanea) hybrids of rice. Grunewald and Bury propose that an insertion effect that stimulated tiller formation in the EP3 crop parent of these hybrids offers a more convincing explanation of our results than direct effects of a transgene for over‐expressing 5‐enolpyruvoylshikimate‐3‐phosphate synthase (epsps) (our central hypothesis). In our study, the genetically engineered (GE) segregants had significantly greater expression of epsps and produced significantly greater amounts of the enzyme of EPSPS than the non‐GE segregants, as expected (Wang et al., 2014). As discussed later, we doubt that an insertion effect could account for the clear and significant increases in our transgenic lines in terms of enhanced fecundity, greater tryptophan concentrations in leaves, and other traits, which are more parsimoniously explained by transgenic over‐expression of epsps and its key role in the shikimic acid pathway (Wang et al., 2014). Tryptophan is produced by this pathway and is a precursor of growth hormones (auxin) and secondary metabolites that play a role in plant defense (e.g. Maeda & Dudareva, 2012). Tryptophan is just one of many products of the shikimic acid pathway, which can account for as much as 35% of a plant’s biomass (e.g. Franz et al., 1997)…
Keywords: Hybrids, Crops, Transgenics, Fitness, GM crops, Oryza sativa, O. sativa f. spontanea, Rice, Rice Hybrids, Arabidopsis thaliana
Citation: Lu, B.R., Snow, A.A., Yang, X. and Wang, W., 2014. Using a single transgenic event to infer fitness effects in crop–weed hybrids: a reply to the Letter by Grunewald & Bury (2014). New Phytologist, 202(2), pp.370-372.
