Deep in the ocean, sunlight can hardly reach, yet there are plants found here.How?
Answers
Brown and red algad are only found as deep as enough light can penetrate for photosynthesis, which is not that deep when you consider how deep the ocean really is.
Some have special adaptions to low light like iridescence.
They also tend to grow slowly. Less photosynthesis means less energy and a slower growth rate.
On land, most plants that are adapted to very low light are also slow growers for the same reason, and if you put them in bright sun, they burn.
Blue leaves help begonias harvest energy in low light
Iridescent Algae, possibly Fauchena laciniata
Those structured chloroplasts also offer a survival benefit, the new research shows: They help the plants collect light. In a hybrid of two species — Begonia grandis and Begonia pavonina — the structures enhance the absorption of green and red wavelengths by concentrating these rays on light-absorbing compartments within the iridoplasts. Importantly, the structures slow the light. The “group velocity,” or the speed of a packet of light waves, is decreased due to interference between incoming and reflected light. The slowdown gives the plant more time to absorb precious sunbeams.
“These iridoplasts can basically photosynthesize at low-light levels where normal chloroplasts just simply could not photosynthesize,” says study coauthor Heather Whitney, a plant biologist at the University of Bristol in England. Iridoplasts, however, can’t hold their own in bright light. So begonias also have standard chloroplasts, which provide energy in plentiful sunshine. Iridoplasts act like “a backup generator” in dim conditions, Whitney says.
Other plants have structured chloroplasts, too, so begonias might not be alone in their feats of light manipulation.[1]
(Brown and red algae are actually not even plants. They evolved separately, but some people classify them with plants. There are things deep in the ocean that slightly resemble plants, but those are animals.)
Footnotes
[1] Blue leaves help begonias harvest energy in low light