GMO Golden Rice Trials Fail - Stunted Growth and Reduced Yield

Rice (Oryza sativa L.) is a major food crop of the world, essential for the survival of more than half of the world’s population. Worldwide, approximately 480 million metric tons of milled rice is produced annually, with about 90 percent of the world’s rice produced and consumed in the six Asian countries (China, India, Indonesia, Bangladesh, Vietnam and Japan). Developing nations, particularly in Asia, are heavily reliant on rice for their dietary caloric requirements.

Inherently, the endosperm of rice lacks provitamin A, resulting in a serious vitamin A deficiency among populations eating predominantly rice. In theory, enriching rice endosperm with provitamin A via genetic engineering (GE) may alleviate vitamin A deficiencies; the resulting product is known as Golden Rice 1 (GR1), a series of lines developed from a long grain rice variety Cocodrie by Syngenta, which has accumulated up to 7μg/g carotenoids per endosperm. However this process is entirely synthetic, as rice is unable to incorporate provitamin A via conventional breeding. 

Image by Jkwchui on Wikimedia Commons

The highest increase in carotenoids levels within rice was accomplished when enzymes with higher activity were replaced by others in previous series. This replacement was shown to boost the production of carotenoids, reaching up to 37 μg/g in a separate long grain rice variety Kaybonnet, is referred as Golden Rice2 (GR2) series.

In an attempt to commercialize GE rice, researchers at the ICAR-Indian Agricultural Research Institute (ICAR-IARI), have crossed the GR2 series with an Indian rice, Swarna, and were faced with some surprising results. The GE plants resulted in abnormal and stunted growth, as measured by size, and reduced yield, as measured by grain number, when compared to the non-GE parent, Swarna.

The researchers have identified several causes of the results, including but not limited to, an imbalance in hormones, and unintended effects from introgression, leading to a significant reduction in chlorophyll. The reduction in chlorophyll may be the culprit causing the reduction in growth and yield - clearly a deep, systemic problem for GE developers.

Nonetheless, this experiment sheds light on the unintended consequences of genetically modifying organisms. In fact, these effects would have gone unnoticed had this experiment not taken place.

Comparison of plant phenotype among transgene homozygous (A), hemizygous (B) and null (C) lines in relation to the RP Swarna (D). A) Reduced plant height of transgene homozygous plant in comparison to a hemizygous plant and the RP Swarna. B) Reduced panicle size and poor panicle exertion in a transgene homozygous plant in comparison to a hemizygous plant and the RP Swarna.

GE Golden Rice is far too often hyped by GMO proponents as a victory for genetic modification, claiming that these products will "feed the world" and save developing nations from dietary deficiencies. This new study emits uncertainty on the accountability  of not only Golden Rice, but the biotechnology industry as a whole.

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References

Bollinedi, H., S., G., Prabhu, K., Singh, N., Mishra, S., Khurana, J., & Singh, A. (2017). Molecular and Functional Characterization of GR2-R1 Event Based Backcross Derived Lines of Golden Rice in the Genetic Background of a Mega Rice Variety Swarna. PLOS ONE, 12(1), e0169600. http://dx.doi.org/10.1371/journal.pone.0169600