Research to probe weeds for genetic treasure

Chemical manufacturers, life science companies and scientists specializing in weed biology and genomics are teaming up to learn more about the genetic makeup of some of the world’s most ubiquitous and costly weeds.

The International Weed Genomics Consortium will be led by weed scientists at Colorado State University in Fort Collins, Colo., and will involve collaborating academics at more than 15 universities around the world.

Industry partners in the project include Corteva, Bayer Crop-Science, BASF, Syngenta and CropLife International.

Together, the IWGC partners hope to develop high-quality genome maps for some of the world’s most costly, invasive and hard-to-control weed species, such as kochia, ragweed, wild oats, crab grass, green foxtail and Palmer amaranth.

By gaining a more complete understanding of the weed genomes, their structures and the genes they contain, scientists hope to develop new and more effective chemistries capable of controlling some of the most common agricultural weeds in North America and around the world.

The project could also lead to the development of novel non-chemical control systems and the creation of more resilient agricultural crop varieties that are better equipped to cope with harsh environmental conditions such as droughts, floods, heat, frost and other abiotic stresses.

The IWGC project received $1.5 million in funding from the Foundation for Food and Agricultural Research in Washington, a government funding agency created by U.S. Congress to explore public-private partnerships in agricultural research.

FFAR funding was matched by the project’s industry partners, which will gain preferential first access to the assembled and annotated weed genomes for one year.

After that, the genomes will be made available for public access and research purposes.

The IWGC’s academic and industry partners are assessing weed genomics work that has already taken place around the world to determine what information is already available, as well as how existing information can be improved and augmented.

Ultimately, the project’s partners will settle on a list of top priority weeds, each of which will have its own “gold-standard” genomic map.

The consortium is seeking additional partners that have expertise in the area of weed genomics. Potential Canadian partners include weed scientists at Agriculture Canada and at western Canadian universities, IWGC organizers said.

Ag Canada scientists have already done work on a high quality genome map for horseweed.

“If you think about the weeds in your own yard or in your own fields, they’re really very resilient and they’re one of the most adaptive species out there when it comes to survival,” said Jeff Rosichan, a director at FFAR, who is helping oversee the consortium’s work.

“We believe that by studying the genomes, the gene sequences, annotating them and understanding more about the genes themselves and how weeds have evolved, there’s a lot of biology there that could really be used to address other problems and challenges … that are facing global agriculture today.”

As it stands, research in the area of weed genomics has been piecemeal and has lacked global co-ordination.

Researchers in some countries have sequenced the genomes of individual weed species. However, the quality of some weed genomes is poor or incomplete.

Some genomes are incomplete and may have gaps while others require further study and annotation.

One of IWGC’s first tasks is to conduct an inventory of weed genomics work that has already taken place.

Consortium partners will build on that foundation in hopes of pushing weed genomics research to a new and more complete level of understanding.

In addition to contributing to the development of new and more effective weed control chemistries, the knowledge gleaned could support research that leads to more resilient and productive cultivated crops for the global agriculture sector.

Through smart breeding technologies such as gene editing, the genetic information gleaned from the weed genomes could be applied to cultivated crop species in hopes of creating plant varieties that are more productive under a wider range of environmental conditions.

The research could also have important implications for the North American organic sector, said Rosichan.

“When you think about organic production, they have the same (weed control) issues as conventional growers, but they just don’t have as many tools to fight them.

“One of our hopes is that some of this research is going to translate into knowledge that will contribute to better solutions for organic growers.”

In addition, plant breeders could potentially borrow genetic resources from resilient and widely adapted weed species to create new and more productive transgenic crop varieties that are less prone to environmental stresses.

That could be an important consideration, given current concerns about global climate change and its potential impact on agricultural productivity.

“There’s a lot of really interesting biology that (may tell us) about how weeds organize their genomes or how their genomes have changed in order to be so adaptable,” Rosichan said.

“My hope is that we’ll be able to use some of that knowledge and to translate it to some of our (cultivated) crop species to make them more resilient and more adaptable.”

Todd Gaines, the IWGC project director and associate professor of molecular weed science in CSU’s Department of Agricultural Biology, said using the “whole genome” approach to advance knowledge of weed biology has been a long time coming.

“When you think about weeds, what makes them great is they are adapted to the harshest situations,” Gaines said.

“They are the most cold-tolerant, the most salt-tolerant, the most-heat tolerant.”

Knowledge gained about weeds’ stress tolerance could be applied to crops, Gaines said.

And traditional weed management strategies could be improved or retired.

In a recent interview, Gaines used kochia as an example of a weed that may hold valuable biological secrets with the potential to improve farming practices and advance global food production.

“It (kochia) comes out… early in the spring and yet it survives these frosts and snowstorms that happen in the spring… and it flowers in the hottest part of the summer,” he said.

“That’s one thing about weeds is they have a lot of traits that are really well adapted to stress tolerance and to surviving in really difficult situations, so we’re really interested in studying that.”

The research could also lead to a better understanding of herbicide tolerance in certain weed species and ways to manage it.

“The problem of herbicide resistance continues to increase around the world and in pretty much every system that you’re looking at that relies on herbicides for weed control we find problems with resistance,” Gaines said.

Public weed researchers have traditionally had problems accessing funding for genomics work because research capacity in weed science is limited, relative to research capacity in crop science.

By partnering with major life science companies, public weed researchers are able to access funding from government sources.

Overall, genomics research has become less expensive and more accessible, Gaines said. That means better access for researchers studying organisms such as weeds, which traditionally haven’t garnered as much attention as major agricultural crops, Gaines added.

IWGC project manager and CSU research scientist Sarah Morran called weeds the “wild west of genetics.”

“Yes, we want to help growers deal with weeds, but to me it’s more about understanding them, and how we can fit them into more integrated pest management strategies,” Morran said.

The IWGC is hoping to complete 10 top-priority weed genomes within three years.

Life science company Corteva is providing the expertise and resources.

Results and information gleaned from the project will be shared through annual conferences sponsored by the United States Department of Agriculture National Institute of Food and Agriculture.

The first conference is slated for September 2021 in Kansas City, Missouri.

More information on the IWGC can be found at weedgenomics.org.