Genetic factors in woodland strawberries promote cold tolerance

Climate change is shifting the seasons, pushing crop plants to their limits. For example, sudden frost episodes in late spring can be detrimental to strawberries in the bed. Wild species, on the other hand, are often more resilient.

Researchers at Karlsruhe Institute of Technology (KIT) and partners have decoded the cold reactions of woodland strawberries to enable the cultivation of more resilient varieties. They have published their findings in the Journal of Experimental Botany.

In the past, crops were primarily bred for productivity—at the expense of resilience. “Climate change makes it more difficult even for modern agriculture to compensate for the lack of resilience found in crops caused by fertilization and field maintenance,” says Professor Peter Nick from KIT’s Joseph Gottlieb Kölreuter Institute for Plant Sciences. “Wild plants and their genetic resilience factors are therefore becoming increasingly important for agriculture.”

His team investigated the cold resistance of woodland strawberries (Fragaria vesca) and thus laid the foundations for more resilient breeding lines in the future. For their research, the scientists resorted to the German Gene Bank for Crop Wild Relatives.

Causes of resilience decoded

In a comparative study, the scientists first identified cold-tolerant and cold-sensitive genotypes of woodland strawberries. A pair of genotypes, contrasting in their tolerance to cold stress, made it possible to uncover physiological, biochemical, molecular, and metabolic processes associated with cold tolerance.

“We were able to observe specific differences in how they handle cold stress,” says Nick. On the one hand, these are differences that have already existed before the stress sets in. “Certain cold-regulated genes are much more pronounced in the cold-tolerant genotype. These provide for the production of proteins that act as the cell’s own antifreeze and protect the membrane from freezing damage.”

On the other hand, there are differences that are caused by cold stress only. As Nick explains, this is at first just a physical signal for the plant: “Cold stiffens the membrane of the plant cell, which has an effect on transport processes and enzyme activity.”

This physical signal must then be effectively converted into a chemical signal and reach the cell nucleus. “We have now identified the genes that are particularly important in this cold-signal cascade and ensure the successful response of the robust woodland strawberry,” says Nick.

Cold-resistance to be transferred to cultivated strawberries

The findings of the study are of great value to agriculture. Says Nick, “In the future, we will be able to use these results for the cultivation of strawberries that produce more of the antifreeze protein, for example. There is no need for genetic engineering, but we can use conventional cross-breeding. Backed by our molecular knowledge, we will be able to quickly select suitable plant individuals.”

For Nick, the study also demonstrates the importance of gene banks: “The example of the woodland strawberry shows that analyzing wild species can help us make agriculture more sustainable and resilient in the future.”