Insects that feed on starch can find veritable feasts in corn, pea, and bean crops or warehouses. It is no coincidence that the ancestors of these commercial plants developed α-amylase (alpha-amylase) inhibitor proteins, which make the starch in their seeds indigestible to pests, keeping them from becoming serious threats. However, the domestication of wild plants by humans to increase productivity and digestibility may have reduced the presence of these inhibitors.
In an article published in the Biotechnology Journal, an international group of researchers discusses the advances made in the last two decades and emphasizes the potential of gene editing to develop plants that produce these inhibitors in greater quantities to combat insect pests. Of course, care must be taken at the same time to ensure that the plants are digestible to humans and other non-target organisms, such as livestock.
The group of authors was led by researchers from the Brazilian Agricultural Research Corporation (EMBRAPA) and the Genomics for Climate Change Research Center ( GCCRC ), an Applied Research Center ( ARC ) supported by FAPESP at the State University of Campinas (UNICAMP).
"In the early 2000s, there were many advances in this area, such as the prospecting of genes encoding alpha-amylase inhibitors in different plant species, the evaluation of the specificity of these molecules against alpha-amylase enzymes in insect pests and non-target organisms, and the development of transgenic plants that overexpress these molecules. Advances were also made in protecting intellectual property through patents filed and granted," says Marcos Fernando Basso , a researcher at the GCCRC with a scholarship from FAPESP and first author of the article.
However, the use of classical transgenics, which involves inserting genes from other species into the genome of plants of interest, discourages biotechnology and food production companies from developing and exploiting their final product. New transgenic organisms for human consumption would risk low market acceptance, in addition to high regulatory costs.
Potential
Bedbugs, beetles, weevils, and woodworms are popular names for insects that produce amylase enzymes. These enzymes convert the starch molecules found in the leaves and seeds of important agricultural crops into sugars. In their adult or larval stages, these pests can attack seeds in fields and during storage, causing economic losses and compromising food quality.
Bruchids, such as the weevil and woodworm, were among the first targets of these technologies due to the significant damage they cause, particularly to grains stored long-term. In this food-rich environment, they reproduce rapidly. Infestation can occur during pod development and persist in storage and during commercialization.
Alpha-amylase inhibitors have also proven effective against other insects. For example, the boll weevil (Anthonomus grandis) feeds on the sugars produced and stored in cotton flower buds. Similarly, the coffee berry borer (Hypothenemus hampei) is an insect whose larvae feed on coffee seeds.
The authors point out that developing varieties with higher alpha-amylase inhibitor production – provided it does not inhibit amylase enzymes in humans and non-target organisms – has great potential when using gene editing techniques.
Using these techniques to increase the expression or modify the DNA sequence of a plant's own genes may enable the creation of plants that are not considered transgenic by the National Technical Commission on Biosafety (CTNBio). CTNBio is the technical-scientific body responsible for formulating, updating, and implementing the National Biosafety Policy for Genetically Modified Organisms (GMOs). Consequently, these technologies would be more likely to be accepted in the market. Therefore, they would be of interest to agribusiness companies for commercialization.
"Gene editing using the technique known as CRISPR [a tool that allows precise and specific genetic modifications to be made to DNA chains or genomic rearrangements to be generated] and its variations gives us the possibility of increasing the production of these inhibitors or making them more active in plants of interest to act specifically against insect pests, without the molecules being a problem for humans and animals that consume the plants or seeds. Therefore, it may be a promising path in the coming years," concludes Basso (read more about CRISPR at revistapesquisa.fapesp.br/en/a-tool-to-edit-dna/ ).
About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe .
