Research on insect-resistant genetically modified (IRGM) rice in China has been going on since 1989. It wasn’t until 2009 that the first two types of IRGM rice were commercialized. The two current types available in China are of Bt rice lines, both based on cry1, the most widely used herbicide worldwide. In a review by Chen et al. (2011) the authors examined the history and importance of rice production in China, the research process of IRGM rice along with the future of IRGM rice in China. They also examine the global, environmental, and socioeconomic impacts of IRGM rice. Since China is the largest rice producer and consumer in the world and its main priority is the feed the 1.3 billion and growing population. Yield loss caused by stem borers has increased tremendously in the last decades, resulting in more than 5 billion Yuan (US $735 billion) dollars each year. One approach to increasing yield is the use of IRGM rice, which has the ability to kill off stem borers. According to Chen et al. (2011) laboratory and field tests have confirmed that Bt rice can provide effective and economic control of the lepidopteron stem borer species with less economic risk than current non-GM practices. —Rachel Warburton
Chen, M., Shelton, A., Gong-yin, Y., 2011, Insect- Resistant Genetically Modified Rice in China: From Research to Commercialization, Annual Review of Entomology, 81-95
The amount of rice grown in China accounts for 18% of the total amount grown worldwide. It serves as a staple food for over a billion residents in the country and there are six main rice-growing regions in the country. Rice yield loss is extremely detrimental to China both economically and socially. In 1989 Chinese scientists from the Chinese Academy of Agricultural sciences engineered Crystal (Cry) proteins into rice plants in order to create the first IRGM rice plants. Twenty years later it was certified and commercialized by the same academy after extensive research. Many scientists and farmers feel IRGM is the only way to produce the amount of rice necessary to feed the nation; they also see a fault with the heavy reliance on traditional insecticides for health and environmental reasons and believe GMO plants may be able to help solve this problem. China is the most populated country in the world and in order to not create food scarcity in other countries due to importation of rice, China needs to be growing their own staple food such as rice.
There are two general insect pest types when dealing with rice: chewing insects and sucking insects. Chewing insects include rice stem borers, leaffolders and rice water weevils and sucking insects include planthoppers and leafhoppers. Many different control theories and practices have been developed for these pests yet many farmers still most commonly utilize synthetic insecticides due to a lack of education or understanding of the modern technologies such as IRGM. This has resulted in a doubling of the amount of pesticides used since 1990 on Chinese crops, consequentially severe insect outbreaks, pollution, and food poisoning are coming after effects.
Although the Bt research began in the late 1980s it wasn’t until late 2008 when China started a 26 billion Yuan (U.S. $3.5 billion) research and development initiative for GM plants, which eventually turned into mainly the commercialization of IRGM rice plants. Thus far IRGM plants have been widely accepted in China for their economic, environmental and yield increase benefits, but there are still concerns being raised about intellectual property rights, governmental regulation and educational outreach to the farmers and consumers. Based on the regulation policy for agricultural GMOs in China, GM crops are forced to go through three tiers of field-testing before being certified for commercialization. The three tiers include pilot field testing, environmental release testing and preproduction testing. Each year hundreds of applications are submitted for testing. Thus far only two biosafety certificates have been awarded for the production of Bt rice. Both lines are composed of a cry1Ab/Ac. China will soon become the first nation in the world to commercialize IRGM rice which should have a positive global influence. Other types of IRGM rice are currently in development and going through the three tier tests. Some of those being developed work with stacked traits of herbicide resistance, disease resistant or even both. Aside from the three-tier research tests safety assessments are also conducted on GM plants. Safety assessments are divided into five stages: laboratory research, the three tier testing, and an application for biosafety certification. Criticisms have been raised however in the current regulations and assessments because the decision making process relies primarily on the National Biosafety Committee which has 75 members, of which the majority are biotechnologists.
Since the release of the BtIRGM rice plant, numerous lab and field studies have been conducted on its environmental and food safety. Between the years of 1995 to 2009 there were over 400 peer-reviewed papers that included laboratory and field studies on these impacts. In general negative effects of IRGM rice did not stand out compared to those of conventional farming techniques. The only data that contrasted with this belief were from research conducted on silkworm larvae. The data suggest that some IRGM rice pollen may be toxic and therefore a hazard to this species.
The authors also explored the potential effects on soil biota and cross-pollination. Since cultivated rice is primarily self-pollinating there is very little cross-pollination between GM and non-GM rice cultivars. The field studies conducted on this matter suggested the risk of cross-pollination was manageable. Lin et al. also has a developed a build in strategy for containing transgenic in GM rice. Food safety was also assessed and they found no significant differences within nutritional components (crude protein, amino acids, etc.). The researchers did however find a compositional difference of three amino acids, two fatty acids and two vitamins between disease-resistant and insect-resistant GM rice grains and non-GM controls.
Bt rice has increased yield by up to 9% compared to non-Bt rice grains based on a household survey conducted in Hubei and Fujian Provinces. There have also been fewer reports of insecticide poisoning with the farmers who use IRGM rice. Overall the effects of IRGM rice have so far been positive.
The main hesitation with IRGM rice, however, is insect resistance. Especially with Bt crops the high dose/refuge, which calls for high expression of insecticidal protein in IRGM plants, have strong theoretical evidence of insect resistance. The Bt protein in Bt rice is lower than that in Bt corn which may make a difference.
In order to successfully implement IRGM rice in a healthy way for the economy and environment of China, the knowledge gaps of IRGM rice must be better understood. More attention should also be paid to identifying new insecticidal genes with different modes of action than just the first-generation rice lines currently being researched. Luckily the new initiative on GM plants in China will help scientists work on these issues and hopefully identify what the best approach is to meet the needs of the people.