A field trial to assess the environmental biosafety of codA-transgenic Eucalyptus camaldulensis cultivation

Abstract

The first Japanese field trial testing the effects of genetically modified (GM) forest trees was conducted over a period of 4 years. Salt tolerance was conferred on Eucalyptus camaldulensis by introducing the soil microbe-derived choline oxidase (codA) gene into this plant. Three individual lines were planted in an isolated field owned by the Gene Research Center at the University of Tsukuba, following approval for type I use by the Ministry of Education, Culture, Sports, Science and Technology, Japan, and the Japanese Ministry of the Environment. Soil populations of fungi, actinomycetes, and bacteria fluctuated during sampling, but any differences introduced were observed only transiently, and no long-term change in the population was observed during the trial. Both the soil-mix as well as the sandwich method was employed to evaluate allelopathic activity of codA-transgenic E. camaldulensis. By the soil mix method, both GM and non GM-derived plant samples were found to exert negative allelopathic effects on seed germination, with an annual fluctuation. Overall, no significant differences were observed between the transformant lines and their bulk seed-derived non-transformants. The sandwich method also revealed an annual fluctuation. A comparison of the non-transformants and transformants revealed no significant differences in their allelopathic activity. Considering the practical use of these transgenic E. camaldulensis, they will no doubt be planted in some salinized sites. Thus, evaluating their impact on the ecosystem in saline conditioned fields might be important in the future.

…Fell Upas Sits, the Hydra-Tree of Death †, or the Phytotoxicity of Trees

“…Initially, the effects of codA on allelopathic activity of transgenic Eucalyptus camaldulensis [345] or E. globulus [346] were tested under net-house conditions. In addition, long term trials were carried out for transgenic E. camaldulensis [347] and E. globulus [346] in Japan. Authors had evaluated the allelopathic effects of eucalypts on test species Lactuca sativa using sandwich and soil mix methods, and no significant differences were found between the transgenic and non-transgenic plants.…”

Environmental risk evaluation of the transgenic Brassica napus lines harboring serine acetyltransferase gene from Nicotiana tabacum

“…Several aspects, such as transgene integration, expression, variety of plants, plant physical state, alterations in root secretions, and soil condition may have intended or unintended implications on the function and structure of soil microbes (Butler et al 2003;Green et al 2007). While many of the transgenic plants for different traits have been reported to pose no apparent risks to environmental biosafety (Lottmann et al 2010;Yu et al 2013aYu et al , 2013c, a negative impact of the transgene event on microbial activities has been reported in some studies (Chen et al 2012).…”

Development and evaluation of novel salt‐tolerantEucalyptustrees by molecular breeding using anRNA‐Binding‐Proteingene derived from common ice plant (Mesembryanthemum crystallinumL.)

“…We have speculated that the breeding of abiotic stress‐tolerant plantation trees could be one way to combat global climate change and contribute to the sustainable development of humankind. We have conducted molecular breeding of abiotic stress‐tolerant Eucalyptus trees using genetic resources of abiotic stress‐tolerant genes from halobacteria and/or halophytes (Kikuchi et al ., ; Matsunaga et al ., ; Oguchi et al ., ; Tran et al ., ; Yu et al ., , ,b,c,d). Mangrin was found to be a candidate salt‐tolerant gene isolated from a cDNA library from suspension‐cultured cells of a mangrove plant, Bruguiera sexangula by a functional screening for cDNA encoding proteins essential for salt tolerance (Yamada et al ., ).…”