Wheat is one of the most important food crops for human beings, and its cultivation history can be traced back to tens of thousands of years ago.

The most awaited part of the wheat growing process is its ripening period when the wheat field will show a beautiful golden colour.

Do you know why wheat turns golden yellow when it matures? Is there any mystery behind it?

The colour change of wheat is determined by its chlorophyll content.

Photosynthesis is the basis for plant growth and development, and it converts water and carbon dioxide into organic matter and oxygen.

Chlorophyll is a pigment in plant leaves that can absorb light energy from sunlight and convert it into chemical energy for plants to do photosynthesis.

Chlorophyll is green, so plants appear bright green when they contain enough of it.

When wheat reaches maturity, its growth slows down, and it no longer needs as much photosynthesis to make organic matter.

At this point, the wheat's chlorophyll content gradually declines, and several other pigments become visible. These pigments include things like carotenoids and flavonoids, which are yellow or orange. When these pigments take over, the wheat turns green to golden yellow.

Other plants in nature experience similar colour changes.

Plant colour changes are mainly determined by the amount and type of pigments in their bodies.

The content and type of these pigments are affected by various factors, such as light, temperature, pH, metal ions, and chromium.

For example, chlorophyll synthesis decreases when the light intensity decreases or the temperature drops. In contrast, the synthesis of carotenoids and anthocyanins increases, causing the leaves to change from green to yellow or red.

When the pH of the vesicle is low, anthocyanins appear red; when the pH of the vesicle is high, anthocyanins appear blue.

When anthocyanins form complexes with specific metal ions or other colourless flavonoids, a chromatic effect occurs, making the colour darker or bluer.

So, the reason why wheat turns golden yellow at maturity is not an accidental or meaningless phenomenon but the result of an adaptive evolution that is prevalent.

By regulating its chlorophyll and other pigment content, wheat can change its colour depending on its growth stage and environmental conditions.

Plant colour change is a universal phenomenon, and it also reflects the adaptability and regulation of plants to environmental changes.