Reading the signs: Plants and animals found common ground in response to microbial threats

November 19, 2010

Though it's been at least a billion years since plants and animals shared a common ancestor, they have through the eons shared a common threat in the form of microbes, including bacteria, eukaryotes and viruses. This has resulted in remarkably similar mechanisms for detecting the molecular signatures of infectious organisms that hold promise for the future treatment of infectious diseases in humans.

The recognition of microbial signature molecules by host receptors is the subject of a paper published in the journal Science titled "Plant and Animal Sensors of Conserved Microbial Signatures." The corresponding author of the paper is Pamela Ronald, a plant pathologist who holds joint appointments with the U.S Department of Energy (DOE)'s Joint BioEnergy Institute, where she serves as Vice President for the Feedstocks Division and directs the grass genetics program, and with the University of California (UC) Davis, where she is a professor of plant pathology. Co-authoring the paper with Ronald was Bruce Beutler, an immunologist and mammalian geneticist with 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 says. "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."

In the Science paper, Ronald describes how the long-held presumption that the mechanisms of plant and animal defense against microbes are separate and distinct has undergone a complete change.

"Discoveries over the past 15 years demonstrate that the mechanisms that allow plants and animals to resist infection show impressive structural and strategic similarity," Ronald says. "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."

While host sensor-mediated immune responses are essential for innate immunity in both plants and animals, sustained or highly induced immune responses can be harmful, which makes negative regulation of these pathways critical. In animals, negative regulators act at multiple levels within certain molecular signaling cascades, but little is yet known about the negative regulation of plant innate immunity.

"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," Ronald says, adding that this approach has already been demonstrated in transference work with cultivated rice and wheat varieties, as well as with tobacco and tomato.

"There may also be room to engineer resistance in vertebrates as well, including humans," she says.

In the Science paper, Ronald speculates that some microbes might be pathogenic to humans because they have managed to evade detection by human Toll-like receptors. Now that some of the essential building blocks of immunity have been elucidated, she believes it may be possible to manipulate these receptors so that microbes can no longer evade them.
The Joint BioEnergy Institute (JBEI) is one of three Bioenergy Research Centers funded by the U.S. Department of Energy to advance the development of the next generation of biofuels. It is a scientific partnership led by the Lawrence Berkeley National Laboratory (Berkeley Lab) and including the Sandia National Laboratories, the University of California campuses of Berkeley and Davis, the Carnegie Institution for Science, and the Lawrence Livermore National Laboratory.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California for the DOE Office of Science. Visit our Website at

DOE/Lawrence Berkeley National Laboratory

Related Infectious Diseases Articles from Brightsurf:

Understanding the spread of infectious diseases
Physicists at M√ľnster University (Germany) have shown in model simulations that the COVID-19 infection rates decrease significantly through social distancing.

Forecasting elections with a model of infectious diseases
Election forecasting is an innately challenging endeavor, with results that can be difficult to interpret and may leave many questions unanswered after close races unfold.

COVID-19 a reminder of the challenge of emerging infectious diseases
The emergence and rapid increase in cases of coronavirus disease 2019 (COVID-19), a respiratory illness caused by a novel coronavirus, pose complex challenges to the global public health, research and medical communities, write federal scientists from NIH's National Institute of Allergy and Infectious Diseases (NIAID) and from the Centers for Disease Control and Prevention (CDC).

Certain antidepressants could provide treatment for multiple infectious diseases
Some antidepressants could potentially be used to treat a wide range of diseases caused by bacteria living within cells, according to work by researchers in the Virginia Commonwealth University School of Medicine and collaborators at other institutions.

Opioid epidemic is increasing rates of some infectious diseases
The US faces a public health crisis as the opioid epidemic fuels growing rates of certain infectious diseases, including HIV/AIDS, hepatitis, heart infections, and skin and soft tissue infections.

Infectious diseases could be diagnosed with smartphones in sub-Saharan Africa
A new Imperial-led review has outlined how health workers could use existing phones to predict and curb the spread of infectious diseases.

The Lancet Infectious Diseases: Experts warn of a surge in vector-borne diseases as humanitarian crisis in Venezuela worsens
The ongoing humanitarian crisis in Venezuela is accelerating the re-emergence of vector-borne diseases such as malaria, Chagas disease, dengue, and Zika virus, and threatens to jeopardize public health gains in the country over the past two decades, warn leading public health experts.

Glow-in-the-dark paper as a rapid test for infectious diseases
Researchers from Eindhoven University of Technology (The Netherlands) and Keio University (Japan) present a practicable and reliable way to test for infectious diseases.

Math shows how human behavior spreads infectious diseases
Mathematics can help public health workers better understand and influence human behaviors that lead to the spread of infectious disease, according to a study from the University of Waterloo.

Many Americans say infectious and emerging diseases in other countries will threaten the US
An overwhelming majority of Americans (95%) think infectious and emerging diseases facing other countries will pose a 'major' or 'minor' threat to the U.S. in the next few years, but more than half (61%) say they are confident the federal government can prevent a major infectious disease outbreak in the US, according to a new national public opinion survey commissioned by Research!America and the American Society for Microbiology.

Read More: Infectious Diseases News and Infectious Diseases Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to