Rice (Oryza sativa L.) GR2E, IR-ØØGR2E-5 is produced with the intention of reducing VAD (Vitamin A deiciency) in vulnerable populations. Genetically modified rice GR2E has inserted genes; psy, crt1, pmi. Two of these genes have been inserted to enable the development of provitamin-A in rice. Together, an inserted psy gene and crt gene mainly lead to significant concentrations of beta-carotene in the rice plant. This genetically modified rice has pro-vitamin A in the white of the seed. Ordinary rice has no vitamin A and will contribute to a vitamin A deficiency where there is predominant rice consumption. There is low-certainty evidence that rice fortified with vitamin A can reduce vitamin A deficiency.
A psy gene from maize (Zea mays) has been inserted into rice GR2E. The gene psyI codes for the enzyme (ZmPSYI). This maize enzyme is phytoene synthase which can convert two molecules of geranylgeranyl pyrophosphate into phytogen. Phytogen is the precursor to a step to make beta-carotene, which can be converted further into Vitamin A in the body.
A crt1 gene from the bacterium (Pantoea ananatis) has also been inserted into rice GR2E, which codes for the carotene desaturase enzyme (CRTI) and which can lead to lycopene formation. Lycopene has a red color and is the cause of the red color in tomatoes. Lycopene can be poorly water-soluble and attaches mostly to the plant's fiber. In genetically modified rice for Vitamin A, lycopene becomes a substrate to form beta carotene which has an orange-yellow colour.
Genetically modified rice plants have also been developed with resistance to insects such as: GM Shanyou 63 and Huahui No.1, and herbicides such as LLRice E06 and LLRice E63. Genetically modified rice GM Shanyou 63 induces delta endotoxin with an inserted gene from the bacterium Bacillus thuringiensis subspecies kurstaki. The cry1ab gene and cry1ac gene have been inserted, leading to CRY1Ab and CRY1Ac delta endotoxins, - which give this rice plant resistance to lepidopteran insects, by damaging their midgut. Shanyou63 has shown high resistance to target insects.
Genetically modified rice Huahui No.1, HZU-HHØØ1-9 is genetically modified to be able to kill the larvae of the Asian rice borer; Chilo suppressalis. Genes originating from bacteria (Bacillus thuringiensis) have been inserted for the expression of Cry1Ab/Cry1Ac toxins. Cry genes code for Cry proteins. These proteins form crystals that lead to cell death after absorption into the cells. Uptake in the cells can take place through receptor binding in the cell's surface. Inside the cell, the toxicity of Cry toxin is probably dependent on magnesium ions (Mg2+). The interactions; Cry-toxin and receptor and magnesium, leads to necrosis of the cell. Cry1Ab/Ac is lethal against C. suppressalis larvae that feed on these rice plants. They can reduce the extent of damage caused by these pests by reducing them by over 85% numbers. The species occurs mainly in Asia.
Rice varieties with herbicide resistance have also been developed. These are LLRice E06 (ACS-OSØØ1-4) and LLRice E63, (ACS-OSØØ2-5). Both of these have been developed to be resistant to herbicides with the active substance glufosinate. They have inserted the bar gene which originates from the bacterium (Streptomyces hygroscopicus). The bacterium has probably been selected from medium with spores of glufosinate. The gene that confers resistance to glufosinate has been inserted into rice. This means that these genetically modified rice plants can withstand levels of glufosinate that are lethal to all weeds. It also means that the unwanted spread of these rice plants, for example as hybrids with other rice plants, must be combated with means other than glufosinate.