Nov 20, 2010 08:58 GMT  ·  By
Despite having gone their separate ways at least a billion years ago, plants and animals have developed remarkably similar mechanisms for detecting the molecular signatures of infectious organisms
   Despite having gone their separate ways at least a billion years ago, plants and animals have developed remarkably similar mechanisms for detecting the molecular signatures of infectious organisms

Biologists now estimate that the last common ancestor between animals and plants lived more than a billion years ago, but they say that the two classes of lifeforms have maintained similar mechanisms of detecting pathogens such as microbes, bacteria and eukaryotes.

These organisms are a tremendous threat to both plants and animals, especially because they can trigger the development of a host of dangerous conditions, that can ultimately lead to the demise of the creature or plant they infect.

As such, detecting the molecular signature of each of these pathogens is a trait that is essential for survival. What experts discovered in a new study is that animals and plants share similar mechanisms for doing so.

Such investigations are not only important for understanding the role of evolution in shaping all living things on Earth, but also for potentially developing new cures for infectious diseases in the human population as well.

The new research study, called “Plant and Animal Sensors of Conserved Microbial Signatures,” appears in the latest issue of the top journal Science. The corresponding author of the paper is scientist Pamela Ronald, while the coauthor is expert Bruce Beutler.

Ronald is a professor of plant pathology at the University of California in Davis (UCD), and also a researcher with the US Department of Energy (DOE) Joint BioEnergy Institute.

She holds joint appointments at the JBI, where she is the Vice President of the Feedstocks Division, and also the director of the grass genetics program. Her colleague, Beutler, is an immunologist and mammalian geneticist at the Scripps Research Institute.

“If evolution is depicted as a tree, and extant species as terminal leaves on that tree, we must acknowledge that we have examined only a few of those leaves, gaining only a fragmentary impression of what is and what once was,” Ronald argues.

“In the future, a diverse array of evolutionarily conserved signatures from  pathogenic microbes will likely be discovered and some of these will likely serve as new drug targets to control deadly groups of bacteria for which there are currently no effective treatments,” she goes on to say.

Over recent years, the long-held idea that animals and plants use different mechanisms for recognizing pathogens has changed, as many studies have revealed more similarities than anyone imagined.

“We now know that plants and animals respond to microbial signature molecules using analogous regulatory modules, which likely came about as a consequence of convergent evolution,” Ronald explains.

“Characterization of new host sensors will pave the way to inter-specific and inter-generic transfer between plants of engineered receptors that confer resistance to a variety of pathogens,” she goes on to say.

“There may also be room to engineer resistance in vertebrates as well, including humans,” the expert concludes, quoted by scientists at the DOE Lawrence Berkeley National Laboratory (Berkeley Lab).