Scientists Tap Tree Genomes to Discover Adaptation Strategies

Source: Virginia Tech
Date of Publication: January 5, 2015
Links: http://www.sciencedaily.com/releases/2015/01/150105092922.htm

Summary:
After decades of extrapolation about gene function in trees based on gene function from a tiny, less complex plant, a team of scientists has finally sequenced whole genomes from 544 unrelated trees of the same species. This accomplishment makes it easier for the scientists to understand the significance of gene variation for the environmental adaptations of trees. For example, the scientists identified two related genes from Populus, a type of deciduous flowering tree species that lives in northern hemisphere. This type of tree contains FT 1 gene and FT 2 gene. The FT 1 gene was known to regulate the transition to flowering and FT 2 gene is important for controlling fall growth cessation and bud set. This gene variation helps the tree to survive because they control the timing of both dormancy transitions in spring and fall. They are like an alarm clock, they tell the trees when to bloom and when to sleep. This gene variation is also an example of adaptation because the area where the Populus grow has four seasons. Therefore, Populus adapted to the environment genetically. Unfortunately, according to Professor Brunner, this example is just a notable exception. It is going to take a while for scientists to derive more conclusions. She said, "The challenge is that we have identified all these genes but don't yet have a good idea of their function." Currently, most of the knowledge of what genes are important for environmental adaptation of trees has been evidentiary guessing that built upon the model plants. Brunner also stated that they need to do more in the actual tree system rather than relying solely on extrapolating from model herbaceous plants.

Relevance:
This article is related to what we have learned in Chapter 14, Evolution: A history and a process. Specifically, in Concept 14.1, we learned that adaptation is an inherited characteristic that improves an organism's ability to survive and reproduce in a particular environment. In this case, genetic variation played a key role in the adaptation of Populus tree. If there is only FT 1 gene, the trees could die because they cannot adjust to fall and winter. In turn, if the FT 2 gene is missing, the trees would not bloom in spring. And based on the concept of the artificial and natural selection, the trees that do not bloom may have some issue with the next generation because they cannot spread their seeds as easily as other plants do. And humans might cut down those kind of trees because people might think they are useless according to their plain-looking. Additionally, in the article, it also mentioned that Poopulus is a type of deciduous tree. According to Concept 34.3, the temperature deciduous region tend to be very cold in winter and quite hot in summer. So this genetic variation is extremely important for the trees like Populus to adapt to such environment.