Everywhere Science!!!

How do the colored leaves of croton plants carry out photosynthesis?

A croton plant is a tropical plant with bright foliage. They grow in a wide range of shapes and hues. It is an ornamental plant. It is also known as Codiaeum. They are flowering plants and classified under the family Euphorbiaceae. Their leaves are differently colored due to different types of pigments like Chlorophyll, Carotinoids and Anthocyanins present in them.  But do the colored leaves perform photosynthesis?

What is Photosynthesis?

Photosynthesis is a process in which green plants use energy from the sun to transform water, carbon dioxide, and minerals into oxygen and organic compounds. It is a light reaction.

Photosynthesis happens only during the day. When water is absorbed by the roots of green plants and is carried to the leaves by the xylem and carbon dioxide is obtained from air that enters the leaves through the stomata and diffuses to the cells containing chlorophyll. The green pigment chlorophyll is capable of converting the active energy of light into food that can be stored and used when needed.

Photosynthesis provides us with most of the oxygen we need in order to breathe. We, in turn, exhale the carbon dioxide needed by plants. Plants are very important to human life because we rely on them as a source of food for ourselves and other requirements such as medicines, housing, industries, clothing etc. Animals also depend on these plants for their food and shelter. Thus there is inter-dependency between plants, humans and animals.

Why do the Croton leaves appear colored?

The leaves of the croton plant contain pigments like Chlorophyll, Carotinoids and Anthocyanins. Chlorophyll absorbs the red and blue light from the sunlight that contacts the leaf and reflects green light.  Therefore, the light reflected or transmitted through the leaf is deficient in red and blue light, so it appears green to our eyes. “Green” is the type of light used by chlorophyll. When a leaf has a high concentration of chlorophyll relative to other pigments, the leaf appears green.

Carotinoids absorb the blue-green and blue light from the sunlight that contacts the leaf. Light reflected by carotinoid pigments appears yellow or yellow-orange to our eyes. When a leaf has a high concentration of carotinoids relative to other pigments, the leaf usually appears yellow.

A third class of pigments found in leaves is the anthocyanins. Anthocyanins absorb blue, blue-green and green light. When leaves contain high concentrations of anthocyanins relative to other pigments, the leaves appear red or purple to our eyes. Purple leaves usually have high anthocyanin concentrations relative to chlorophyll. The pigment anthocyanin absorbs green light and reflects reds and purples. Therefore, the leaves “appear” purple to our eyes.

The chlorophyll is present in the croton leaves embedded along with Carotinoids and Anthocyanins. The colored pigments Anthocyanin and Carotinoids assist the pigment Chlorophyll in the process of photosynthesis. So, plants with leaf color other than green perform photosynthesis just like green-leafed plants. The chlorophyll needed for photosynthesis is masked among the colorful pigmentation. If the leaves do not perform photosynthesis, then the plants will die!!!!