To find the pivotal points in the scientific research we used a program called cite space. With the help of ISI web of knowledge, where you download and search through numerous articles related to Golden Rice, you are able to produce a visual diagram of how the scientific research is organised. Cite space highlights key articles that are cited and used as references in different fields of research. It also highlights specific clusters of research and how they relate to each other, usually around the same key article that is described below. This allows us to deeply analysis the literature surrounding the science of Golden Rice.
Golden Rice, before any legitimate research was published, seemed to be a fantasy of the future. Ingo Potrykus and Peter Beyer had a project full of possibilities and potential, but nothing was official as of yet. It wasn’t until 2000 when “Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm” was published in Science Magazine by Xudong Ye and a group of co-authors, including Potrykus and Beyer. (See article 1) I found this pivotal article by using CiteSpace, a program that analyzes a surplus of scientific articles and finds the one that is most influential. http://cluster.cis.drexel.edu/~cchen/citespace/
The article notes that generically grown rice (Oryza sativa) is often milled in tropical countries to reduce the risk of it spoiling in storage. This process removes the natural vitamin A in the rice, resulting in a nutrient deficiency, causing serious health problems. By using Recombinant DNA technology, scientists are able to improve the nutrient content of the rice. To synthesize beta-carotene (which later is converted to pro-vitamin A in the body) within the rice, three different plant enzymes are introduced to the rice endosperm: phytoene desaturase, zeta-carotene desaturase, and lycopene beta-cyclase.
This scientific research was the pilot for continued Golden Rice study and research. There are three particular clusters of research that have utilized this article and branched off of it in effort to validate newer research on Golden Rice, as well as separate research. The first cluster has researched the possibility of increasing the amount of vitamin A content in the rice. A fundamental argument of Golden Rice is that vitamin A content is so small that an unreasonable amount of rice must be eaten to receive the nutrient benefits. (See article 2)
The second research cluster is focused on other food sources that have the potential to be genetically modified such as maize and tomatoes, to help counties suffering from nutrient deficiency. Ye’s article is cited by this group, as they use it as an example of how genetically modifying nutrient content of crops is possible. (See article 3 and 4)
The third research cluster has cited Ye’s paper to prove their own research is legitimate. In order to strengthen research, which is totally unrelated to Golden Rice research or GM crops, they relate their projects and make the claim that what they are doing is scientifically sound with the already research beta-carotene biosynthesis article. (See article 5,6, and 7)
(1) Ye, X, et al., 2001. Engineering the provitamin A biosynthetic pathway into rice endosperm, science, Vol 287 (5451): 303 (2) Paine, J. A., 2001. Improving the nutritional value of Golden Rice through increased pro-vitamin A content, Nature Biotechnology: http://www.nature.com/naturebiotechnology (3) Aluru, M., 2008. Generation of transgenic maize with enhanced provitamin A content, Journal of Experimental Botany, vol 59 (13): 3551-3562 (4) Romer, S. et al., 2000. Elevation of the provitamin A content of transgenic tomato plants, school of biological science, research articles, Natural America Inc: http://biotech-nature.com (5)Hirschberg, J., 2001. Carotenoid biosynthesis in flowering plants, plant biology, Vol 4 (3): 210-218 (6) Shewmaker, CW. et al., 1999. Seed-specific overexpression of phytoene synthase: increase in carotenoids and other metabolic effects, plant journal, Vol 20 (4): 401-412. (7)Dobbermann, A., 2002. Site-specific nutrient management for intensive rice cropping systems in Asia, field crops research, Vol 74 (1): 37-66.