Genetically modified (GM) tomatoes look much the same as traditional varieties. But are they? By comparing the chemical diversity of strains of GM tomatoes with a control strain and traditional reference cultivars, a research team in Japan has developed a way to distinguish between them.
Consumers need to be confident that GM tomatoes are safe, so initial risk assessments must show that they are ‘substantially equivalent’ to traditional varieties in their chemical make-up. Scientists can then focus on those chemicals, or ‘metabolites’, found only in particular GM varieties for toxicological testing.
As a case study, the team—led by Kazuki Saito of the RIKEN Plant Science Center in Yokohama—focused on GM tomatoes over-expressing a foreign gene encoding miraculin, a substance normally found in a tropical plant but not tomatoes. Miraculin is a glycoprotein—a protein with short carbohydrate side chains. It has the remarkable ability to make sour foods taste sweet. “Miraculin has fewer calories than sugar and has potential as a natural sweetener and flavor enhancer,” Saito notes.
Metabolism refers to the processes involved in maintaining life, including the building and breakdown of proteins, nucleic acids and carbohydrates. Complex metabolic pathways involve many enzymes and the chemical constituents of cells and tissues are in constant flux.
Whereas genomics provides an overview of the genetic composition of an organism, ‘metabolomics’ can give a snapshot of biochemical status. “We applied metabolomic techniques to compare the chemical diversity of GM tomatoes to that of traditional varieties,” Saito explains. Because there is currently no single technique for separating and characterizing all metabolites, the researchers used a range of metabolomic techniques to assess the chemical diversity of GM tomatoes over-expressing miraculin.
“Our multi-platform approach allowed us to identify metabolites in both types of tomato in an automated manner, and to evaluate variation between them using robust statistical methods,” says Saito.
The researchers found that the ripening GM tomatoes had a reproducible metabolic signature, and that over 92% of their metabolites showed an acceptable range of variation similar to that of the traditional varieties.
“Our aim was not to show that the GM tomatoes are safe, but rather to examine the chemical diversity of GM tomatoes compared with natural variants, and to possibly narrow down the list of potentially problematic metabolites as a guide to further investigation,” explains Saito.
The team believes that their multi-platform approach could be applied to any GM organism as a start to objective risk assessment.
The corresponding author for this highlight is based at the Metabolomics Research Division, RIKEN Plant Science Center
 Kusano, M., Redestig, H., Hirai, T., Oikawa, A., Matsuda, F., Fukushima, A., Arita, M., Watanabe, S., Yano, M., Hiwasa-Tanse, K., Ezura, H. & Saito, K. Covering chemical diversity of genetically-modified tomatoes using metabolomics for objective substantial equivalence assessment. PLoS ONE 6, e16989 (2011).
Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex
New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences