Causonis japonica, a plant native to Japan, is the first to exhibit the newly identified characteristic. Depending on the stage of its maturity cycle, its flowers might change color before returning to their original color. Causonis japonica is the only flower species known to exhibit bidirectional color change, despite the fact that many flowers have been found to change color based on their stage of maturation. Understanding the flowers’ color-changing techniques may help improve nutrient yields in some food crops since the pigments involved in the hues are related to nutrient-rich colorful veggies.
We all enjoy flowers, and one of their most alluring qualities is probably their broad variety of sizes, forms, and, of course, colors. However, did you know that some flowers have the ability to change their color? Although not all of them are flowers, this characteristic has been noted for at least a few decades in hundreds of different species. It is believed that flowers that change color do so to let pollination insects know that they can expect nectar or pollen rewards in the form of the flower. This signal is seen as being “honest.” The opposite is also true; some plants send out a “dishonest” signal in which some of their flowers exhibit their default hue while others do not. This activity is believed to make the plant more visible overall to potential pollinators from a distance. But regardless of the plant’s approach, every instance of a color-changing bloom that has been discovered has been unidirectional. The color does not change back once it has changed. So, picture the shock Professor Hirokazu Tsukaya of the University of Tokyo must have had when he witnessed a flower of the Causonis japonica plant changing color, then changing color again, and then changing color again.
The bidirectional color-changing flowers were an entirely unexpected discovery, according to Tsukaya, even though he had extensively examined the plant and had learned there were at least two types in 2000. Professor Nobumitsu Kawakubo, a colleague of mine from Gifu University, is an expert in time-lapse, lengthy video recordings of flower pollination. Initially, he and his student attempted to investigate the pollination practices among the various varieties of Causonis japonica and anticipated witnessing the recognizable transformation from its natural orange color to a vivid pink. They watched the time-lapse video again and were astounded to see that it oscillated between the two states and not only changed back to orange once more. They informed me of this discovery, which prompted us to inquire as to its origin. So we began working together.
Tsukaya was able to link the physiological changes that occurred in the flowers at the same time as their color changes through the use of meticulously filmed time-lapse movies from the field and in-depth laboratory studies.
According to Tsukaya, the male stage of flower development, when nectar is secreted, coincides with the bloom’s early orange state. “The male stamen, or stamen, ages and detaches, turning the blossoms pink. A few hours later, the pistil, which is the female part, starts to mature and secrete nectar, which causes the flower to turn orange once more. The blossom turns pink when that phase is over. Orange-yellow carotenoid is the principal pigment responsible for color change, and it also has the fastest cycle of accumulation and decomposition to date. Another thing that surprised us was that fact.
You’ve probably noticed that the chemical name carotenoid has a certain carrot-like ring to it. This is not a coincidence since the same molecule is responsible for the orange color of regular carrots. It’s a good source of vitamin A, and given that the color-changing flowers exhibit the fastest accumulation of carotenoids ever observed, it should come as no surprise that the researchers believe their discovery could one day be used to create vegetables rich in carotenoids that mature more quickly or produce more vitamin A.
Our next steps, according to Tsukaya, “will be to understand what is directing the behaviors we have observed.” “The degree to which the stages of the cycles are regulated is one important question we have.” Is it brought on by proteins caught in a feedback loop, or does something genetically occur? We will investigate this further in the hopes of quickly coming up with a solution. It’s strange to think that Causonis japonica was once despised by Japanese farmers due to its ferocious nature. But Kyoka Izumi, a novelist, wrote so favorably about them that I wonder if it kept some people interested in keeping them. Whatever the reason, I’m happy they are still alive and able to tell us their secrets. “I’m curious as to what we’ll learn next.”
