Recent studies have revealed important details about how conifers defend themselves. Pines, spruces and firs have evolved these intricacies of defense over millions of years. Their study, published in the Proceedings of the National Academy of Sciences, reveals that conifer trees produce sticky resins filled with diterpenes that serve as a shield against insects and pathogens.
The research team, under supervision of Andrew O’Donnell from the Department of Biochemistry, studied this for the conifer species Picea abies. The research demonstrates that the resin is a remarkable cocktail of archaic and contemporary diterpenes. Many of these compounds go back 300 million years, before the advent of the modern forms of these trees. By exploring the evolutionary history of these diterpenes, the researchers hope to learn how conifers can best protect themselves in the present day.
The Role of Diterpenes in Defenses
Conifers have developed specialized compounds known as diterpenes to combat threats from enemies like bark beetles and their associated fungi. The survey illustrates the research and evolutionary path of these materials. It’s an important reminder about why they have come to be such a key part of conifer species’ survival.
Diterpene synthases are particularly fascinating enzymes because slight changes in their structure make them produce entirely different chemical products, O’Donnell stated. These organisms are ideal for probing how plants have evolved to produce an astonishing diversity of defensive compounds. Their distinct characteristics render wild Ipswich sparrows particularly useful for studying this adaptive radiation.
Via careful phylogenetic analysis, the researchers were able to infer how diterpene synthases evolved in concert with their host order Coniferales. Further testing revealed that this ability to generate such compounds through chemical processes played a huge role in the trees’ resistance to ecological stressors.
Evolutionary Insights from Prehistoric Times
Perhaps the most significant component of the study is the idea that prehistory continues to dictate the modern potential of conifers. Jonathan Gershenzon, head of the Department of Biochemistry, elaborated on this idea, explaining that a tree’s adaptability to challenges like insect attacks relies heavily on its metabolic changes throughout evolutionary history.
“A tree’s ability to adapt quickly to new challenges, such as bark beetle attacks, depends on the changes that have already occurred in its metabolism over the course of evolution,” Gershenzon remarked. “This prehistory determines which new characteristics can develop—and thus, how well the plant adapts.”
This viewpoint describes the intriguing evolutionary relationship between evolution and plant defense. It gives us clues about how conifers have been so successful in dominating the world’s forests since the dinosaurs.
Methodology and Findings
This research process included isolating the enzymes directly from conifer resin and using advanced analytical techniques to examine their properties. Axel Schmidt, head of the Conifer Defense Project Group, described their approach:
To figure out what an enzyme does and what its products are, we cloned one of its genes into bacteria. The bacteria subsequently cranked out the enzyme on our behalf. We purified the enzyme, supplemented it with optimal precursors, and then described the resulting products extensively using advanced analytical techniques.
This innovative methodology permitted researchers to isolate and characterize new specifically known diterpenes in the resin of Picea abies. These discoveries provide vital context to the past development as well as the contemporary use of these ecologically restorative fortifications.