The fastest growing plant in the world is a duckweed. His secret? An extreme simplification of its genome and an evolution optimized for rapid growth. However, this particularity means that it presents several interests in various fields of research.
The fastest growing in the world
The Wolffia (or wolfies) are a genus of floating aquatic plants, commonly known as “duckweed”. These are the smallest plants in the world capable of producing flowers. In a study published in the journal Genomic research on January 19, 2021, researchers from the United States, Germany and India focused on one species in particular: the Wolffia australiana. According to them, this duckweed has the strongest growth among all the other plants. This can indeed double its size in just 24 hours.
In order to understand the secret of Wolffia australiana, the researchers carried out a sequencing of its genome. They also cultivated the plant using a circadian cycle and performed analyzes to understand which genes were active and at what time of day. Remember, however, that most plants grow by following a circadian cycle and tend to grow especially in the morning.
According to the results, only 13% of genes of Wolffia australiana are expressed according to a circadian cycle. However, in the case of most other plants, this rate averages 40%. According to Todd Michael, the lead author of the study from the Salk Institute for Biological Studies (USA), this explains why duckweed is growing so fast. He also indicated that she was able to grow continuously under the influence of light. The other plants are naturally limited by their internal circadian clock.
An ultra-simplified genome
This genetic “simplification” is not the only one concerning this plant. Indeed, other genes usually important for behavior, defense mechanisms or root growth are absent. For Todd Michael, the Wolffia australiana got rid of genes she didn’t need during her evolution. This is what allowed it to evolve to benefit from a capacity for rapid and uncontrolled growth. You should know that this duckweed has a genome of 357 million base pairs (Mb) for 15,000 coding proteins. By comparison, wheat has 15,500 million base pairs.
For scientists, the Wolffia australiana presents several interests. Let us first mention the possibility that become a new model for the study of how genes act on biological activities. The arab () is in fact currently favored by biologists for this kind of work, but it is developing much less quickly.
Then this duckweed could embody a new source of protein for humans or even a base for a new biofuel. Traditionally consumed in Southeast Asia, duckweed could also be used to imagine the creation of new fast growing plants. For the researchers, the interest would be more on plants to be cultivated in an artificial environment under continuous light.