Why is UV important to plants?

Inneedofbuds

Well-Known Member
Why do plants need UV light?
UV increases the level of essential oils in mints & the production of resin by trichomes of relatives, UV is used for maximum yield and quality of these oils.
UV induces color development in flowers, essential for beautiful red veins in green Kale or Chard.
Full Power Flower - UV light needed to fully fill the glandular trichomes of basil. Plants of Ocimum basilicum L. were grown in the absence of UV light, both peltate and capitate glandular trichomes were incompletely developed in both mature and developing leaves, the oil sacs being wrinkled and only partially filled, there was a large decrease in the number of broken oil sacs among the peltate glands as the mature glands broke open, releasing volatiles. the number of glands and the qualitative or quantitative composition of the volatiles were badly affected by the lack of UV light.
Tasty Sunscreen?.With added UV light, an increased level of essential oils yields a more powerful scent and flavour. The essential oils also aid in the absorption of UV light , thus a sunscreen for plants. Plants in the wild produce their own kind of “sunscreen,” called flavonoids. Flavonoids screen out some of the more dangerous UVB-type radiation.

OK, what are these Flavonoids? Flavonoids are antioxidants in fruits, vegetables, tea, and wine - plant nutrients that belong to the polyphenol family. They are really good for you. Flavonoids are responsible for brilliant blues, purples, and greens, as well as yellows, oranges, and reds which cannot be attributed to carotenoids (found in carrots). Carotenoids are fat-soluble, while flavonoids are predominantly water-soluble. Flavonoids are found in more concentrated forms in beans and berries, but also red wine, green tea, and soy products, as well as many common fruits and vegetables. Products are have been developed using these molecules to battle cell and DNA damage involved in cancer, heart disease, diabetes and possibly brain degeneration, by neutralizing"free radicals". Research links them to reduced risks for cancer, heart disease, and other age-related degenerative diseases, as well as antioxidant protection of body fluids such as blood. They also may help prevent stroke, flu, tooth decay, and other ailments. Apple skins rich in flavonoids are discarded in all food products such as juices because the flavonoids in the skin cause cloudiness in the juice. A waste, when you consider the antioxidant activity in apple peel is potent enough to stop cancer cells growing. Flavonoid content is highest in the leaves of St. John's wort (you must know about this flower), and is at maximum concentration during full bloom. In the flowers, the content of flavonoids is highest at the start of flowering, falling during flowering. In tests, St. John's wort (flowers) had the highest content of flavonoids (11.71%) of any of 223 species tested.
Several hundred flavonoids can be found in plants, they are the compounds which affect colour, aroma and flavour.
COMMERCIAL APPLICATION - UV light slows foliar growth and stem length. Bedding plants are often grown from seedlings in greenhouses. The growing conditions in a greenhouse cause many plants to outstrip their containers, growing too tall to be easily transported by the time their color matures. Plants overly tall for their containers may also be aesthetically displeasing, which can hinder their marketing. Height control of greenhouse-grown plants has long been an issue in the bedding plant industry. Chemical growth regulators are often used on ornamentals but are not considered safe on vegetable crops. Using UV light (particularly UVB) to regulate growth is a relatively new, but much safer alternative that works on several bedding plant species as well as select vegetables, exposing plants such as impatiens, tomatoes and cucumbers to UV treatments for a few hours slows their foliar growth and stem length without reducing color or other favorable characteristics.
 

Inneedofbuds

Well-Known Member
ran out of room...


Colour of plants - where's that pigment from?

Colour depends on if your Sunscreen is sweet and on Acid? (not forgetting hydroxycinnamate) Anthocyanin production requires light for photosynthesis in the PAR range. Anthocyanins, such as cyanidin, provide a natural sunscreen for plants. Because the molecular structure of an anthocyanin includes a sugar, production of this class of pigments is dependent on the availability of carbohydrates within a plant. Anthocyanin color changes with pH, which is why soil acidity affects leaf color.
 
Top