Why Do Plants Grow Towards Light?
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Loading... - Blondel Mbe
- 15 Aug 2022
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An international team is now one step closer to explaining a central observation.
Charles Darwin has had a greater influence on science than most. Though his research on the Islands and his theories on evolution are widely known, fewer people are aware of his contributions to plant science. A multinational research team has now achieved a significant advancement in the explanation of a key observation that dates back to Darwin.
Darwin noted that plants might grow in a certain direction in response to environmental cues like light or gravity in his book The Power of Movement in Plants published in 1880. He provided evidence that the portion of the plant that receives the stimulus and the portion that reacts is distinct. Darwin claimed that in order to explain this, an “influence” must move from the domain of stimulus perception to the area of reaction. However, Darwin would never be able to identify this influence.
This “growth accelerating substance” was discovered to be the hormone auxin in 1926, and it was subsequently discovered that auxin is the growth factor that controls the majority of plant responses to environmental changes. However, directed transport of the auxin molecule across cells is necessary to make sure that the auxin response is allocated to the appropriate area of the plant.
In the 1990s, a family of proteins named PIN-FORMED (PIN) was finally identified as essential for this process. They got the name from the distinct morphology derived if they are dysfunctional: The plant became a needle-like ‘pin’, without shoots or flowers.
The PIN proteins turned out to be auxin transporters. Their function is vital for the establishment of auxin gradients within plant tissues. A gradient that subsequently guides plant growth and development. Read More...
