Special Red Leaves
· Plant Team
When autumn comes, the leaves of maple trees gradually turn red. From afar, the mountains are covered with red, and the scenery is very spectacular.
So why do the leaves turn red in the fall?
It turns out that, in addition to chlorophyll, there are many other pigments in the leaves of plants, such as yellow lutein, carotene, and anthocyanins, that change color with PH (pH). Autumn leaf discoloration is mainly related to these pigments.
1. Chlorophyll reduction is the main reason
Deciduous trees, in the fall and winter, will enter the self-dormant adjustment stage, part of the nutrient recycling storage in the trunk or roots, to prepare for the next spring and then use.
Chlorophyll can not be synthesized in large quantities at this time while constantly being decomposed by chlorophyllase or bleached by photo-oxidation, gradually decreasing.
So, in the fall and winter, the leaves first no longer show green.
2. No anthocyanin, no red leaves
When there is a lack of chlorophyll in the leaves, the color of other pigments, such as yellow carotenoids (lutein, carotene), anthocyanins, and so on.
Let's focus on anthocyanins, which belong to the flavonoid group of phenolic compounds.
Anthocyanins are one of the main pigments that make up the color of flower petals and fruits; common blueberries, blackberries, black goji berries, blackcurrants, cranberries, mulberries, purple potatoes, cherries, purple kale, and so on contain anthocyanins.
Anthocyanins have been scientifically proven to be beneficial to the human body as they are strong antioxidants that protect the body from damage caused by harmful substances containing free radicals.
Anthocyanins also enhance the elasticity of blood vessels, improve the circulatory system and smoothness of the skin, inhibit inflammation and allergies, and improve the flexibility of joints.
However, anthocyanins are not red! What does it have to do with fall leaves turning red?
Anthocyanins are water-soluble pigments that change color depending on the acidity of the cellular fluid.
It is reddish when the cellular fluid is acidic, bluish when the cellular fluid is alkaline, and purple when it is neutral.
In the fall, chlorophyll gradually breaks down due to the drop in temperature, and the acidity and alkalinity of the cytosol also change, making anthocyanins red.
In addition, the sugar stored in the leaves also helps to convert the anthocyanins, making the leaves more reddish.
3. Why frost leaves are redder
While the chlorophyll on the leaf surface of frosted leaves is further destroyed, the sugar stored in the branches and leaves increases, making the leaves redder and redder.
According to the amount of anthocyanin and sugar, the leaf surface can form bright red, fishy red, deep red, purple red, and other different colors.