The University of Vienna researchers, along with collaborators from France, Germany, Switzerland, and the USA, have made a significant advancement in understanding the impact of genetic drivers on the evolution of a particular photosynthesis mechanism in Tillandsia (air plants). This discovery provides insight into the intricate processes that drive plant adaptation and ecological diversity.The research team’s findings on plant species’ water-saving trait called Crassulacean Acid Metabolism (CAM), including the adaptation in most Tillandsia species, have been published in Plant Cell. CAM plants, such as those in the Tillandsia genus, optimize their water use efficiency by opening their stomata at night to absorb carbon dioxide for photosynthesis, storing it for later use. This adaptation allows CAM plants to survive with minimal water.Several times throughout the plant kingdom, CAM has evolved independently. However, the complex genetic basis of CAM has been difficult to understand, leading to a focus on research in evolutionary biology.
In this study, the research team examined a pair of Tillandsia species that have different forms of photosynthesis – CAM vs. C3. This means that the C3 species does not have the specialized adaptation to arid conditions. The team used advanced techniques to study the plants’ genetics and biochemistry, such as analyzing gene arrangements, molecular and gene family evolution, and differential gene expression over time.The study found that changes in gene regulation are the main driver of CAM evolution in Tillandsia, rather than changes in the sequences that code for proteins. Clara Groot Crego, from the University of Vienna, explained that while large-scale changes have influenced Tillandsia’s genomes like other plants, the adjustment of how photosynthesis works mainly happens through the regulation of genes. The study was funded by the Austrian Science Fund (FWF) and the University.
The study conducted by Ovidiu Paun and his team at the University of Vienna focused on identifying CAM-related gene families that have undergone accelerated expansion in CAM species. This emphasizes the important role of gene family evolution in creating new variations that contribute to CAM evolution.
Expanding into New Environments through Repeated Evolution
Ovidiu Paun, from the Department of Botany and Biodiversity Research at the University of Vienna, explains that CAM has evolved multiple times in different species of Tillandsia, enhancing their ability to colonize new ecological niches. This has been a key factor in the significant speciation observed within this group.
The study highlights the potential significance of genetic innovation in driving ecological diversification, going beyond just changes in base pairs,” Paun adds.
Thibault Leroy, the lead researcher from INRAE Toulouse, France, emphasizes that this research has implications beyond basic science. “Understanding how CAM evolved can help develop strategies to make crops more resilient to water shortages and cope with climate change.”
The study will be expanded to include more species within this and other plant groups as part of a new collaborative project jointly funded by the Austrian Science Fund (FWF) and the French National Agency.Research paper (ANR).
Source:
- Clara Groot Crego, Jaqueline Hess, Gil Yardeni, Marylaure de La Harpe, Clara Priemer, Francesca Beclin, Sarah Saadain, Luiz A Cauz-Santos, Eva M Temsch, Hanna Weiss-Schneeweiss, Michael H J Barfuss, Walter Till, Wolfram Weckwerth, Karolina Heyduk, Christian Lexer, Ovidiu Paun, Thibault Leroy. The evolution of CAM is linked to the expansion of gene families in a rapid bromeliad radiation. The Plant Cell, 2024; DOI: 10.1093/plcell/koae130