Читать книгу Dry Beans and Pulses Production, Processing, and Nutrition - Группа авторов - Страница 53

Thus far, no commercially available bean varieties developed through genetic modification (GM) or through gene engineering are being marketed in the US. Beans have lagged behind soybeans in the utilization of this technology for a number of reasons (Veltcheva et al. 2005; Song et al. 2020). The major reason was the absence of an incentive to develop a GM bean by private industry as the acreage base is so small compared to soybean. This meant that there was limited investment or financial resources targeted to develop a GM bean, either in the public or private sector. In addition, the smaller acreage planted to dry beans is dispersed over six to eight major market classes in addition to the different horticultural types, so no economic incentive existed to pursue the development of GM bean as any financial returns would be small. Since beans are cropped with soybeans, the private sector did not want herbicide‐resistant volunteer beans appearing in the soybean or corn crop the following season. The additional hurdle was the recalcitrant nature of beans to regeneration and plant transformation.

All major grain legumes, including cowpea, peanut, and pea, have been genetically transformed, and beans continue to resist transformation using Agrobacterium. This has been a formidable hurdle, and one that was bypassed by colleagues in Brazil who have successfully transformed beans using a particle gun (Bonfim et al. 2007). This was the first use of RNA interference technology to achieve this remarkable result of engineered Gemini Virus resistance to Bean Golden Mosaic Virus in the field (Aragão and Feria 2009), which has since been moved into commercial “carioca bean” cultivars (Souza et al. 2018). These varieties were engineered to express resistance to the Gemini Virus pathogen Bean Golden Mosaic Virus. This was the first use of RNA interference technology to achieve this remarkable result of engineered Gemini virus resistance in the field (Aragão and Feria 2009).

The cost to deregulate GM beans in the US is estimated at over $10 million for each GM event but the revenue generated by the crop across diverse states and seed and pod types is insufficient to support deregulation. This bodes well for consumers who are “anti‐GMO foods” or for European markets that similarly continue to exclude GM products. The downside is that bean producers cannot avail themselves of the same production technologies as soybean producers, which will result in a competitive loss of bean acreage in many production states. Lower acreage will undoubtedly result in smaller crop production and higher prices to the consumer. This fact alone is concerning, given the new evidence of the valuable health benefits of increasing bean consumption in the US diet to help combat obesity, diabetes, and certain cancers (Thompson et al. 2009). The US bean industry with limited research support needs to address this question in a rational and reasonable fashion using science‐based research. Breeders are consistently asked to make progress and compete with GM crops such as soybean, yet they are limited in the tools they can use to address future production needs and challenges. Perhaps CRISPR (Zaidi et al. 2020) will provide an affordable consumer‐accepted gene‐editing technology to engineer improved traits for common bean in the near future.