Published 2018-10-09

This post is also available in Swedish

Research progress on field cress

Research on field cress (Lepidium campestre), a wild oilseed plant, has been under way for 20 years. Now the scientists have found 30 important genes that, it is hoped, can help to speed up domestication of this oil crop.

Field cress is a herb with undistinguished flowers and soft, greyish, hairy leaves. Found rarely in southern and central Sweden, it tends to grow on road verges and embankments. It may not sound particularly exciting, but this plant has aroused researchers’ interest for decades, one reason being its potential as an alternative to oilseed rape. Despite the great efforts made, the breakthrough has been slow going — until now.

The research scientists, who work in Mistra Biotech, have now identified variants of 30 important genes in the genetic material — genes that determine, for example, when the plant blooms, the quality of its oil and how firmly the seeds are attached to the plant before harvest. This knowledge can be crucial when it comes to choosing the right specimens for domestication of the wild species.

Another explanation for the researchers devoting such great efforts to a single plant is that it would be suitable for arable cultivation in these northerly latitudes. There, it has the potential to serve as both a biennial oil crop and a catch crop that absorbs excess nutrients from other cultivation that would otherwise leach into watercourses.

What has impeded cultivation of field cress so far is that it retains a few ‘wild’ traits that are unsuitable for cultivation systems. These are precisely the variations in traits that the scientists have now surveyed.

Genetically, the field cress species shows marked similarities to the rest of the plant genus Lepidium.

‘By studying the closely related Smith’s pepperwort (Lepidium heterophyllum) and Mediterranean pepperweed (Lepidium hirtum), we can utilise some of their good qualities,’ explains Cecilia Gustafsson, one of the researchers behind the study.

Field cress is also closely related to thale cress (Arabidopsis thaliana), a model plant that is very well studied regarding which genes govern which traits. The researchers can now benefit from this knowledge by, for example, looking for genes in field cress that resemble known genes in thale cress. In this way, they have found the field-cress genes for vernalisation (the process whereby exposure to cold conditions induces a plant to bloom), flowering period, seed retention, and quantity and quality of oil.

The study was funded by the Mistra Biotech research programme and the Swedish Foundation for Strategic Research, and recently published an article in the scientific journal BMC Genetics. This article, by Cecilia Gustafsson, Jakob Willforss, Fernando Lopes-Pinto, Rodomiro Ortiz and Mulatu Geleta, may be found here:

https://doi.org/10.1186/s12863-018-0624-9.

Facts about field cress

Researchers in Mistra Biotech have long been trying to domesticate this biennial oil crop. The hope is that its winter-hardiness will make it an interesting alternative to oilseed rape. According to estimates, harvesting up to five tonnes per hectare will be feasible, but much remains to be done before this can be achieved. The scientists’ primary aim is to raise the oil content and change the composition of fatty acids.

As a first step, researchers are trying to use genetic engineering to obtain a plant with the required properties. After that, they will try to achieve the same results using traditional plant breeding, so that it will later be possible to commercialise the plant in Europe.

Since field cress is biennial, it can be undersown with one of the Nordic region’s common cereal varieties. When these are harvested, the field cress keeps growing for another year. This reduces nutrient leaching and the need for tillage, and helps to make agriculture sustainable.

Text: Per Westergård