Corn for the cows without rain, thanks to genetics

A sun-drenched day on the fields of the Institute for Agricultural, Fisheries and Food Research in Wetteren, Flanders, southeast of Ghent. A strong wind makes the bone-dry cropland disappear. It couldn’t be more appropriate for a trial with drought-resistant maize.

About twenty lab technicians, researchers and students, affiliated with the city university and the Flemish Institute for Biotechnology, got down on their knees in the sand. In the absence of garden tools, they use a plastic test tube to make a hole in the bottom every 15 centimeters as deep as an inch. The ground is still a little moist there.

On this Thursday, after months of study in a laboratory, the team led by Hilde Nelissen, professor of plant biology at Ghent University, is seeding maize kernels of the non-commercially available variety B104 into three grains of maize after “a minor adjustment” in the genetic material. months should have grown into man-sized plants with full-fledged cobs, regardless of whether the cropland continued to be scourged by the drought that has persisted in Western Europe since March and threatens to burden farmers with large yield losses.

It was PhD student Jessica Joossens (36), now happily tossing in the soil, who discovered a gene in the maize plant in a dataset from a colleague a year and a half ago that causes the DNA material to fold under ‘drought stress’ so that it becomes inactive; as a result, the plant stops growing until water is available again, or dies if this is not forthcoming. Using the crispr-cas method, in which genes can be influenced individually, Joossens looked at what happened when that gene was switched off. Corn is one of the crops whose genome has been extensively mapped. Moreover, according to Joossens, it is ‘a really nice plant to work with’, because ‘easy to grow, measure and transform’.

smeared with earth

In a greenhouse and greenhouses, the plant continued to grow even in persistent drought. The hope is now that ‘the crispr maize’ will also do the same in the field, so that farmers, the target group of this study, can now be assured of sufficient animal feed. But not only in times of drought, says Joossens, her dress and tights are smeared with earth. “We have already seen that this gene works in heat and low light. This maize could also withstand that.”

According to Hendrik Vandamme, chairman of the General Farmers’ Syndicate, Belgian farmers have been looking for drought-resistant maize for years. “We have only had one relatively normal year since 2018,” he says over the phone. “And that was last year. Especially 2020 was extremely dry, with hardly any precipitation and a mild northeasterly wind that provided an extra drying effect. It’s no better this spring. Then you, as an agricultural sector, start thinking: do we have alternatives for cultivation?”

Corn is originally subtropical and only came to Europe from Mexico fifty years ago, after which breeders made the plant suitable for a more northern climate over the years. The crop is an important component in the feed of ruminants – cows, sheep – because, unlike grass, they get a large part of their energy from it. In France, maize fields are irrigated as standard, but there is not enough fresh water in Belgium, says Vandamme. And so farmers with breeders, but also with institutes like Hilde Nelissen’s, are looking for a way out. Because it is beginning to dawn that the drought will only get worse.

Four years ago, Nelissen’s team also conducted a field trial with maize to which genetic material from another species had been added to see whether it could withstand drought. But that crop failed, ironically because the soil was too dry for the kernels to germinate at all. Nelissen, with a smile: “That’s why we sow a little deeper now.”

Groundwater level up to standard

She estimates that this spring 70 percent of Belgian agricultural land will be affected by the drought. And it is also very warm for the time of year. That has a cumulative effect. A lot of rain is needed to bring the groundwater level back up to standard, another extreme actually. And our maize cannot withstand that.”

And so she hopes the drought will continue in the coming weeks. The team visits Wetteren twice a month. To measure the leaves and especially to cut off the male flower in time, to prevent a manipulated plant from spreading through its pollen. That is strictly prohibited in Europe. The cobs are harvested in October.

Jessica Joossens hopes to obtain a doctorate for her drought-resistant maize by then. “Then we will see if we can extend this research to wheat. An even more important crop if possible.”