Although we cannot see them, plants have a series of substances in their petals that attract pollinating insects . The reason they can see them and we can’t is that they are only visible in the ultraviolet spectrum , invisible to humans. According to a study from Clemson University in the United States, these substances act as a kind of target for pollinators and help flowers respond quickly to a changing environment .
Matthew H. Koski is an associate professor of biological sciences in the Clemson School of Sciences who has led the research at hand. He and his team studied the bright yellow flowers of Argentina anserina , a plant in the family Rosaeceae , meaning roses, to learn how pigments in the petals that are visible only in the ultraviolet spectrum play an integral role in the plant plasticity . The plasticity of a plant is known as its ability to respond quickly to a changing environment, such as climate change.
Researchers studied silver algae growing at different elevations in southwestern Colorado to better understand the roles of various UV-absorbing chemicals in plant petals and how these chemicals contribute to pollination and thus , to playback.
Koski explained that while humans can’t see the UV patterns in flower petals, many of their pollinators can.
“I’ve always been fascinated by how color variation arises, how it evolves, and what factors drive the evolution,” Koski said of flower petal colors, “so I got interested in thinking about how we perceive color vs. how the organisms that most frequently interact with flowers perceive color”. “Insects (pollinators, for example) see in the ultraviolet spectrum,” he continued. “So flowers that reflect or absorb ultraviolet wavelengths give (pollinators) the perception of different colors that we can’t see. I’ve been fascinated by discovering what these ultraviolet signals might be doing functionally with respect to pollination. When I thought about the ultraviolet absorption trait of interest, it’s biochemical. It’s a biochemical trait that leads to different perceptions of UV absorption and reflectance.”
The researcher and head of the study points out that a wide range of plants have concentrations of chemicals that absorb UV rays at the base of the flower petals, while the tips of the petals have more chemicals that reflect UV rays. According to him, this creates an overall target-like effect that guides the insects in their search for pollen.
Researchers have also discovered that flowers at different altitudes adapt to their environments by producing different amounts of chemicals that block or absorb UV rays . “At higher altitudes, there are always more UV-absorbing compounds or a larger UV-absorbing spatial area in the petals, compared to low-altitude populations,” Koski said.
The study’s authors claim this demonstrates plant plasticity , which Koski defines as the way different traits arise in the same organisms under different environmental conditions. This is a fundamental step in understanding how organisms adapt to survive change. “The important thing about plasticity is that when we think about climate change and global change, plasticity is a mechanism by which natural populations can respond very quickly to changes in climate and persist through them,” he said. “The process of evolution, in which changes in the genetic code occur over time, is thought to be slower than the plastic response to environmental change.”
One question raised by the research is whether or not the plastic responses of plants to environmental situations are adaptive , that is, whether they offer an advantage to an organism, or are changes in the way a trait develops due to the environment without that this affects the aptitude of the plant. “One of the things this study found is that the plastic change in ultraviolet pigmentation benefited the plant, especially those at high altitudes, because increased ultraviolet absorption in the petals led to increased viability of the plant.” pollen,” Koski explained.
Koski added that the research will help scientists better understand how organisms respond to environmental changes and even predict whether or to what extent some organisms might survive rapid environmental change, such as global climate change. The research could also be important for agriculture, he said, because some of the same UV-sensitive pigments that act in silver algae are also present in commercial crops such as mustard and sunflower.
“It is interesting to think that if abiotic factors (components of an ecosystem that do not have life, but influence the living beings that are part of it), such as UV rays or temperature, modify the expression of these traits, how will impact that on how pollinators view flowers, and how it’s going to affect things like yield and seed production in crops, for example,” Koski said.
The results of the study have been published in the journal Evolution .
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Reference:
H. Koski et.al. 2022. Elevational divergence in pigmentation plasticity is associated with selection and pigment biochemistry. Evolution. DOI: https://doi.org/10.1111/evo.14422
