Are Flower Scents a Casualty of Global Warming?

Can you imagine a world where flowers had no fragrance? They would be alive and even colorful but devoid of the smells we’re used to associating with them. Picture a living rose with its deep red petals and thorny stems but in this picture, as you rest the flower next to your nose to inhale its heady scent, you smell nothing. The rose petals are velvety to your touch; the thorns sharp. Yet the scent you’d expect would be absent.


This picture is not yet a reality but scientists have known that increasing temperatures associated with global climate change have a negative effect on plant growth and their ability to produce scents.


Scientists at Hebrew University in Jerusalem are finding out that ambient increased temperature changes lead to a decrease in the floral scents a plant produces.


In order to understand the root cause of climate change in relation to flowers and their scents, it all begins with reproduction.


Flowers produce scents to attract pollinating insects to its reproductive organs, the carpels, which are the female parts, and the stamens, which are the male parts. Flowers attract insects by assembling a mixture of dozens, and even hundreds, of substances from biochemical groups.


These substances attract insects, insects land on the reproductive parts of flowers, then pollination occurs when the equivalents of human sperm and human ovaries meet when pollen on an insect fertilizes the flower’s ovaries.


Global climate changes are affecting the way plants are able to produce the chemicals that attract insects.


Petunia plants are the subject in a study at Hebrew University in Jerusalem, Israel. Scientists are studying the effects of increases in ambient temperature on the production of their floral scents.


When grown at elevated temperature conditions, their production and emission of scent compounds are significantly defected.


PhD student Alon Can’ani says, “Increases in temperature associated with the changing global climate are interfering with plant-pollinator mutualism.”


Two Petunia varieties, P720 and Blue Spark, are specifically linked to this arrested expression and activity of proteins that facilitate biosynthesis of the compounds that make the scents and the colors of flowers.


The research has led to the discovery that the adverse effect can be bypassed by expressing the Arabidopsis thaliana PAP1 gene. This gene boosts the production of scent with no regard to the ambient temperature.


Climate changes may not conclusively stop flowers from being able to produce their fragrance, but this study is a start in proving the hypothesis of how global warming affects flowers and potentially what science can do to stop this occurrence from happening.



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