Ancient Gene Reveals Deep Evolutionary Roots of Plant Organ Development.

A gene known for its essential role in modern plant root development appears to have a much older evolutionary function, according to new research from Kobe University. The study, published in New Phytologist, reveals that the RLF gene, vital for forming lateral roots in vascular plants, also drives organ development in liverworts—primitive land plants that lack true roots altogether.

Lead researcher Fukaki Hidehiro, a plant biologist at Kobe University, initially identified the RLF gene’s role in lateral root formation in Arabidopsis thaliana, a widely studied model plant. Intrigued by the possibility that RLF’s function might extend beyond root development, his team investigated whether this gene also influences organ formation in more ancient plant species.

To explore this, Fukaki turned to Marchantia polymorpha, an umbrella liverwort considered one of the simplest land plants. Despite lacking roots that absorb nutrients or water, Marchantia possesses its own version of the RLF gene. Through genetic studies, the team demonstrated that liverworts without RLF showed severe abnormalities in various plant organs. Remarkably, the Arabidopsis RLF gene could compensate for the liverwort’s gene, and vice versa—confirming the genes’ interchangeable functionality across species separated by hundreds of millions of years of evolution.

“This shows that the two genes are functionally interchangeable as actors in organ development,” said Fukaki.

The RLF gene encodes a protein within the large family of heme-binding proteins—molecules known for their role in cellular energy transfer. This study is the first to link heme-binding proteins with plant organ development. Fukaki’s team confirmed that the RLF protein indeed binds to heme in both Arabidopsis and liverworts.

These findings highlight a broader evolutionary pattern: mechanisms that emerge for one purpose can later be repurposed. In this case, a gene that predates roots is now indispensable to their development.

Fukaki noted, “The fact that RLF plays an important role in organ development since at least the dawn of land plants is an example of how evolution often co-opts existing mechanisms for new functions, such as root development, which appeared after liverworts and mosses diverged from other land plants.”

This research deepens our understanding of how plant organs evolved and opens new avenues for exploring ancient genetic functions.

Source:https://phys.org/news/2025-05-root-gene-older.html

This is non-financial/medical advice and made using AI so could be wrong.