Breeding Trees Better Adapted for Warmer Climates

Scientists have confirmed the function of a gene that controls the awakening of trees from winter dormancy, a discovery that may be the key to a world in which trees don't have to worry about adapting to warmer climates.

The decade-long study, carried out by the University of Oregon, identified the EBB1 gene - or what they are calling the bud-break gene - involved in producing the first green leaves of spring. This gene is a master regulator in poplar trees (Populus species), and could pave the way towards trees with better adaptability - no doubt an asset in this ever changing climate.

"Having this knowledge enables you to engineer changes when they might become urgent," co-author and forest biotechnology professor Steve Strauss said in a statement.

The results, published in the Proceedings of the National Academy of Sciences, describes how these bud-break genes control when trees open their leaves, when they produce flowers and when they go dormant. These annual cycles are crucial in helping trees adapt to environmental changes, like those associated with climate. However, the genetics have to keep up, Strauss added.

"Will there be sufficient genetic diversity around to evolve populations that can cope with a much warmer and likely drier climate?" he said. "We just don't know."

Harnessing EBB1 may ensure that such trees do exist in the future.

Researchers developed modified trees that overproduced EBB1 genes and emerged from dormancy earlier in the year. In contrast, they also showed that trees with less EBB1 activity emerged from dormancy later.

Specifically, EBB1 is able to do this by coding for a protein that helps to restart cell division in a part of the tree known as meristem. It also plays a role in suppressing genes that prepare trees for dormancy in the fall, and in other processes such as nutrient cycling and root growth that are critical for survival.

While the findings are unlikely to be implemented anytime soon, Strauss adds that as more genes of this kind are recognized, the more opportunity scientists will have to create "genetically modified trees" better equipped to handle Earth's changing climate.