In the Malaysian jungle, there’s an incredible plant with blue leaves known as the peacock begonia (Begonia Pavonina), but the reason for why it is blue is an even more incredible story.
Some of the plant’s chloroplasts – where photosynthesis happens – have a crystal-like structure within them that are able to slow down light. This allows the plant to absorb more green-red light and has the “side-effect” of reflecting out blue light, hence their cobalt appearance to us.
These chloroplasts are incredible and perfect for the low-light environment found on the rainforest floor. The plants have a 5 to 10 percent higher yield than purely green ones.
"It's actually quite brilliant. Plants have to cope with every obstacle that's thrown at them without running away. Here we see evidence of a plant that's actually evolved to physically manipulate the little light it receives," senior author Heather Whitney told Popular Mechanics. "It's quite amazing, and was an absolutely surprising discovery."
The research was conducted by a team from the University of Bristol and University of Essex, and it is published in Nature Plants. The scientists looked at the arrangement of thylakoids, nanoscopic structures within the chloroplasts where the chemical reactions related to the photosynthesis take place.
Usually, thylakoids are randomly distributed within the chloroplast, but in these begonias the compartments are very regularly distributed and act like dense crystals. Thylakoids use the light of the Sun to turn water and carbon dioxide into glucose and oxygen. As sunlight goes through the leaf, the orderly spread of the thylakoids create a quantum effect that slows light down, making it possible for more chemical reactions to take place.
“We discovered under the microscope, individual chloroplasts in these leaves reflected blue light brightly, almost like a mirror,” lead author Matt Jacobs said in a statement. “The inner structure had arranged itself into extremely uniform layers just a few 100 nanometres in thickness, or a 1,000th the width of human hair.”
The researchers think that these special chloroplasts are used as a backup generator when there’s not enough light around. They might also be found in many other plants where they don’t dominate the colors of the leaves.
[H/T: Popular Mechanics]