A study by researchers at the University of Göttingen on Mesotaenium endlicherianum, an alga closely related to land plants, has revealed important genetic insights. By analyzing algae's responses to various environmental conditions, biologists have uncovered genetic mechanisms shared between algae and land plants, deepening their understanding of plant evolution and resilience.
A wide variety of plants grow on most of the Earth's land surface, and they constitute the vast majority of terrestrial biomass. Plants range from delicate mosses to towering trees. This amazing biodiversity resulted from a fateful evolutionary event: the terrestrialization of plants. This refers to the point in time when a type of algae (whose modern descendants can still be studied in the laboratory) evolved into plants and invaded land around the world. A research team at the University of Göttingen led a survey of 10 billion RNA fragments to identify "hub genes".
An international team led by the research team generated large-scale gene expression data to study the molecular networks in one of land plants' closest algal relatives, a humble single-celled alga called Mesotaenium endlicherianum. Their research results were published in Nature Plants.
The researchers used a strain of Endophyllum that had been safely stored for 25 years at the Algal Culture Collection of the University of Göttingen (SAG) and used a unique experimental setup there to continuously expose the Endophyta to a range of different light intensities and temperatures.
Janine Fürst-Jansen, a researcher at the University of Göttingen, says: "Our study first examined the limits of the algae's ability to adapt to light and temperature. We exposed it to a wide temperature range from 8°C to 29°C. We were very curious when we observed a wide range of interactions between thermotolerance and phototolerance based on in-depth physiological analyses."
The researchers not only studied the algae's response at a morphological and physiological level, but also read information from approximately 10 billion RNA fragments. The study used network analysis to simultaneously study the common behavior of nearly 20,000 genes. Among these shared patterns, "hub genes" were discovered that play a central role in coordinating gene expression in response to various environmental signals.
This approach not only provides valuable insights into how algal gene expression is regulated in response to different conditions, but, combined with evolutionary analysis, also reveals how these mechanisms are common to land plants and their algal relatives.
Professor Jande Vries from the University of Göttingen said: "What is unique about this study is that our network analysis can point to an entire toolbox of genetic mechanisms that was unknown in these algae. When we looked at this genetic toolbox, we found that they are shared over 600 million years of plant and algae evolution!"
Armin Dadras, a PhD student at the University of Göttingen, explains: "Our analysis allows us to identify which genes cooperate with each other in various plants and algae. It is like discovering which notes remain in harmony throughout different songs. This insight helps us discover long-term evolutionary patterns, revealing how certain basic genetic 'notes' remain consistent across numerous plant species, much like a timeless melody resonates across different musical genres."