Good results from a drought-tolerant transgenic wheat

There is growing acceptance around the world of a drought-tolerant genetically modified wheat, which will improve food security in regions of the world where, due to global warming, droughts are becoming more frequent, intense and long-lasting.

Now it is the United States government that has approved the cultivation of the aforementioned drought-tolerant wheat, developed by specialists from the National Scientific and Technical Research Council (CONICET) of Argentina.

The United States government, through its Animal and Plant Health Inspection Service (APHIS) of the United States Department of Agriculture (USDA), has authorized the possibility of growing transgenic wheat with HB4 technology (registered trademark), which is drought tolerant, in its territory, without restrictions. In its resolution, the American agency determined that this transgenic variety does not present risks in relation to the non-modified wheat seeds used as a reference. “From a pest risk perspective, this modified plant can be safely grown and reproduced in the United States,” the agency said. This means that it will not be subject to certain specific regulations intended to regulate genetically modified or genetically engineered organisms. This approval is in addition to the one obtained for consumption in June 2022 – granted by the United States Food and Drug Administration (FDA) – and is an important step for its commercialization in one of the main wheat producing countries in the world.

The drought-tolerant HB4 technology, considered unique worldwide, was developed by a team of specialists from CONICET and the Universidad Nacional del Litoral (UNL), led by Raquel Chan, director of the Instituto de Agrobiotecnología del Litoral (IAL, a joint center of CONICET and UNL), in conjunction with the global Argentine company Bioceres Crop Solutions, specialized in agricultural biotechnology. This is a successful public-private partnership lasting more than twenty years that allowed the development of this pioneering technology.

“This is a very important development, given that the United States is one of the world’s largest wheat producers, and the approval means that it can be planted in an unregulated manner; which means that it passed all environmental safety tests and safety for human and animal food. Although the FDA had already approved it for consumption in 2022, this is going to have enormous repercussions: it is not the same to plant only in Argentina and export, than to be able to plant the seeds directly in the United States or other countries. The difference is abysmal,” says Chan.

Since transgenic seeds incorporating HB4 technology are more tolerant to drought, they allow for minimizing production losses, improving the plants’ ability to adapt to water stress situations and providing greater predictability to yields per hectare. The ability of these wheat seeds to offer greater tolerance to drought is provided by the incorporation into their genome of a modified gene, originally taken from the sunflower plant, called HaHB4 (for Helianthus annuus homeobox 4, commercial name HB4).

This technological and productive innovation has already been approved in other important markets such as Argentina, Brazil and Paraguay, which together represent more than 90 percent of the surface area cultivated with wheat in South America. But now, with the authorization for its cultivation in the United States, a new stage has opened for its expansion in the international market.

The United States is one of the main markets worldwide and the fourth after Argentina, Brazil and Paraguay to grant full authorization to produce and market HB4 wheat. This wheat is also currently undergoing field trials in Australia. It is worth noting that HB4 wheat has already been approved for human and animal consumption in 7 other countries: Australia, Colombia, Indonesia, New Zealand, Nigeria, South Africa and Thailand. Applications for HB4 wheat have also been submitted in Bolivia, the Philippines, Uruguay and Vietnam (for human and animal consumption, and cultivation).

As global warming advances, there are areas of the Earth where droughts will become more frequent, intense and long-lasting. Using genetically modified agricultural crops to better resist drought may be the key to avoiding serious food crises in regions where they did not exist. (Photo: Laboratory of the Institute of Agrobiotechnology of the Coast / CONICET / UNL)

Development of a drought-tolerant technology

The research process that Chan and his team carried out to develop HB4 technology had a first turning point in the discovery of a sunflower gene that gives this plant greater tolerance to stress due to water deficit.

In this regard, Chan explains that the research and development process began with a fundamental, pure science question: “How is it that sunflower is more resilient to water stress than soybeans or wheat?” The search to answer that question was a key impetus for the discovery of the HaHB4 gene.

The first trials for the development of transgenic plants consisted of introducing this gene into seeds of Arabidopsis thaliana, a plant commonly used as an experimental model in laboratories, and obtained the expected results: the seeds that incorporated the sunflower gene obtained greater tolerance to water stress.

In partnership with Bioceres, they began testing what would happen when the gene was incorporated into crops of agricultural interest, such as soybeans, corn, alfalfa and wheat, and in most cases they obtained successful results, which were continued in new studies. Studying the behavior of these crops in the laboratory, in the greenhouse and later in the field was a research project that lasted many years, in which specialists in different disciplines such as molecular biology, genetics, agronomy and bioinformatics participated. It is worth highlighting the work carried out by Patricia Miranda and her predecessor Moisés Burachik (deceased) to achieve this regulatory milestone.

“Twenty years ago, when this started, I never imagined we could get to this point,” the researcher confesses.

Chan points out that currently, severe heat waves combined with lack of water are causing havoc to crops, so it is necessary to generate new technologies to add to those already developed. “We are working on that. We want to generate technologies that can give crops resistance to all climatic adversities. HB4 is the first of our technologies to come to light with a partner company, and I hope we will have many more,” he says. (Source: Miguel Faigón / CONICET. CC BY 2.5 AR)