Plant protection

Insect defence

Resistant and
ready for anything

The resistance of crops to insects is more important than ever. Aurélie Bak and her team are looking for innovative solutions, exploring promising candidate genes for the development of new traits.

Small guy, big pest: we are working on innovative solutions to actively combat the cabbage-stem flea beetle.

The challenge? Making our crops even more resilient to insects in the face of climate change and pest control restrictions. Reductions in the use of plant protection products constrain effective pest management approaches. At the same time, climate change drives the spread of pests worldwide. This makes alternative strategies, such as the development of resistance traits in plant breeding, necessary to reduce crop losses in the future.

Aurélie Bak, Senior Research Lead for Trait Development, is taking on this challenge. Together with her team, she identifies genes for trait development at the KWS Gateway Research Center (GRC). They are also developing test assays to investigate the efficacy of these traits under insect attack.

Plant defence mechanisms – such as against the beet moth – are particularly interesting for our research.

The development of insect-resistant traits is becoming increasingly important for us.

Plants have some impressive tricks up their sleeve

But how can a plant defend itself against insects? Over the course of evolution, plants have developed remarkable defense mechanisms, including mechanical strategies such as thorns, hairs, or lignification as well as the production of toxins. In addition, plants use sophisticated strategies such as attracting predators true to the motto “the enemy of my enemy is my friend.” Plants are even able to warn their neighbors so that they can immediately deploy their defense mechanisms in the event of an attack.

“Insects are difficult
to control.”

Aurélie Bak

The team: Junli Zhang, Joy Hungerford, Aurélie Bak, Qi Wang und
 Jocelyn Jackson (from the left).

“I’ve always been interested in the diverse interactions between plants and insects,” says Aurélie Bak. “It’s exciting to research how plants, which are unable to move, are still able to take effective action against herbivores,” she adds. Aurélie Bak is an expert in insects and other plant pests. Her scientific experience ranges from nematodes to virus-transmitting aphids, and she has led many research projects in this field.

Insects pose a unique challenge for our scientists. Unlike plant diseases, insects are mobile. They can choose where they want to attack. Once they do so, they not only cause direct feeding damage, but also render the plant susceptible to additional stress factors such as drought. In addition, insects often introduce diseases by transmitting pathogens from infected plants to healthy ones. “Working with insects presents more challenges than working with viruses or bacteria,” confirms Aurélie Bak. “As part of the trials, we have to exert a certain pressure on the plants to identify resistance but insects are difficult to control. Sometimes you have to wait until they arrive in the field.”


Insect resistance: Development of traits

The development of insect traits is a lengthy process, requiring a deep understanding of the interactions between insects and plants, as well as the underlying molecular processes. “We look closely at which mechanisms the plant naturally uses to defend itself against an insect. Once we understand these mechanisms, we look for the genes that are responsible,” explains Aurélie Bak. “The identification of such candidate genes often involves scientific literature. However, collaborations with universities are also essential to leverage current basic research and further research capacities.” The defense mechanisms of plants are very complex and sometimes highly specific. “We can’t always start from scratch here but leverage existing knowledge from the research community as part of our strategy,” emphasizes Aurélie Bak.

The identification of candidate genes involves collaborative research work. Once candidate genes are identified, they undergo detailed analysis.

Different molecular biological and biochemical methods are used as candidate genes are studied in KWS commercial plant material to understand their function and evaluate potential negative effects on plant growth.

Next, the influence of the genes on insect resistance is tested in special test systems. For this purpose, the plants are exposed to insect pests both in the greenhouse and the field.

A successful line demonstrates increased resistance in the field without a negative impact on the performance of our commercial hybrid material. At this point, the candidate genes can be “handed over” to breeding.

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Curious about how we are battling insect damage? Read more about the cabbage stem flea beetle (in german) and how we are developing new solutions for our plants. |


What are insect assays?

Insect assays are very challenging and need to be adapted for every insect species. It is crucial to know exactly how to evaluate the infestation in order to reliably assess resistance. To this end, the team works closely with the Phytopathology department in Einbeck, using their knowledge and services, but also developing its own test systems. The GRC now even has its own rearing capacity for various insect species.

The group is also well networked with other KWS divisions, underscoring the significance of insect resistance across various departments. For a year now, a dedicated cross-crop task force on insect resistance has been operational. Aurélie and her team meet regularly with colleagues from various other R&D groups and Business Units, discuss current results and jointly develop breeding and agronomic strategies. |

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