Scientists from Purdue University and the Chinese Academy of Sciences have used CRISPR/Cas9 gene-editing technology to produce a variety of rice that can produce up to 31 percent more grain when compared with current strains of rice. To develop the rice, the researchers created mutations to 13 genes that were linked with phytohormone abscisic acid. Essentially the gene editing ‘silenced’ these genes. This plant hormone is related to plant stress tolerance and suppression of growth. By controlling plant stress, the variant with improve yield was produced.
The new process was different to other attempts at genetically modifying rice. Other approaches have used gene-splicing where genes from other plants have been transferred into rice in order to boost its robustness. Here rice plants have been modified to increase micronutrients such as vitamin A, increase grain size, or to accelerate photosynthesis. More controversially, some rice plants have been engineered to tolerate herbicides or to resist pests, meaning that framers are reliant upon specific chemicals produced by global multinationals in order to continue using the crop.
Tests on the new variant rice were conducted in Shanghai, China and on China’s Hainan Island. The types of stresses that the new rice can better withstand include drought, soil salinity plus other environmental factors that lead to a reduced yield for farmers.
CRISPR
CRISPR is an acronym for “Clustered regularly-interspaced short palindromic repeats.” It is a relatively new genome editing tool that functions like molecular scissors. The method allows scientists to modify an organism’s DNA. For a fuller description of the technology, see the Digital Journal article “Is CRISPR technology set to change biological science?“
According to an overview by Engadget, there remain ethical questions to unravel with the new rice. Some environmental groups are concerned with the impact of genetically modified rice on other crops. There is also the issue of who would own the rice and future corporate control. In addition, further tests are required to ensure that the rice is safe and accessible.
The development of the new rice has been published in the journal Proceedings of the National Academy of Sciences. The research paper is headed “Mutations in a subfamily of abscisic acid receptor genes promote rice growth and productivity.”
