Mutualistic symbioses between eukaryotes and beneficial microorganisms of their microbiome play an essential role in nutrition, protection against disease, and development of the host. However, the impact of beneficial symbionts on the evolution of host genomes remains poorly characterized. Here we used the independent loss of the most widespread plant–microbe symbiosis, arbuscular mycorrhization (AM), as a model to address this question. Using a large phenotypic approach and phylogenetic analyses, we present evidence that loss of AM symbiosis correlates with the loss of many symbiotic genes in the Arabidopsis lineage (Brassicales). Then, by analyzing the genome and/or transcriptomes of nine other phylogenetically divergent non-host plants, we show that this correlation occurred in a convergent manner in four additional plant lineages, demonstrating the existence of an evolutionary pattern specific to symbiotic genes. Finally, we use a global comparative phylogenomic approach to track this evolutionary pattern among land plants. Based on this approach, we identify a set of 174 highly conserved genes and demonstrate enrichment in symbiosis-related genes. Our findings are consistent with the hypothesis that beneficial symbionts maintain purifying selection on host gene networks during the evolution of entire lineages.
It is estimated that 100,000 billion bacteria populate the gut of each individual (or 10 to 100 times more than the number of cells in the human body), and their diversity is considerable, estimated to around a thousand different bacterial species...
Hosts: Vincent Racaniello, Michael Schmidt, Elio Schaechter, and Michele Swanson. Vincent, Michael, Elio and Michele discuss how an endosymbiont betrays its aphid host to alert plant defenses, and a new immunosuppressive cell that allows infection...
Coronaviruses are the diverse group of RNA virus. From 1960, six strains of human coronaviruses have emerged that includes SARS-CoV and the recent infection by deadly MERS-CoV which is now going to cause another outbreak. Prevention of these viruses is urgent and a universal vaccine for all strain could be a promising solution in this circumstance. In this study we aimed to design an epitope based vaccine against all strain of human coronavirus.
Since the dawn of agriculture, plant pathogens and pests have been a scourge of humanity. Yet we have come a long way since the Romans attempted to mitigate the effects of plant disease by worshipping and honoring the god Robigus. Books in the Middle Ages by Islamic and European scholars described various plant diseases and even proposed particular disease management strategies. Surprisingly, the causes of plant diseases remained a matter of debate over a long period. It took Henri-Louis Duhamel du Monceau's elegant demonstration in his 1728 “Explication Physique” paper that a “contagious” fungus was responsible for a saffron crocus disease to usher in an era of documented scientific inquiry. Confusion and debate about the exact nature of the causal agents of plant diseases continued until the 19th century, which not only saw the first detailed analyses of plant pathogens but also provided much-needed insight into the mechanisms of plant disease. An example of this is Anton de Bary's demonstration that a “fungus” is a cause, not a consequence, of plant disease. This coming of age of plant pathology was timely. In the 19th century, severe plant disease epidemics hit Europe and caused economic and social upheaval. These epidemics were not only widely covered in the press but also recognized as serious political issues by governments. Many of the diseases, including late blight of potato, powdery and downy mildew of grapevine, as well as phylloxera, were due to exotic introductions from the Americas and elsewhere. These and subsequent epidemics motivated scientific investigations into crop breeding and plant disease management that developed into modern plant pathology science over the 20th century.
Nowadays, our understanding of plant pathogens and the diseases they cause greatly benefits from molecular genetics and genomics. All aspects of plant pathology, from population biology and epidemiology to mechanistic research, are impacted. The polymerase chain reaction (PCR) first enabled access to plant pathogen DNA sequences from historical specimens deposited in herbaria. Historical records in combination with herbarium specimens have turned out to provide powerful tools for understanding the course of past plant epidemics. Recently, thanks to new developments in DNA sequencing technology, it has become possible to reconstruct the genomes of plant pathogens in herbaria. In this article, we first summarize how whole genome analysis of ancient DNA has been recently used to reconstruct the 19th-century potato-blight epidemic that rapidly spread throughout Europe and triggered the Irish potato famine. We then discuss the exciting prospects offered by the emergence of the discipline of ancient plant pathogen genomics.
Global warming is happening now, and scientists are confident that greenhouse gases are responsible. To understand what this means for humanity, it is necessary to understand what global warming is, how scientists know it's happening, and how they predict future climate.
Once the world’s fourth largest lake, the mighty Aral Sea is now in it’s death throws. Starved of it’s lifeblood of the waters of the Syr Darya and the Amu Darya rivers, the sea has been shrinking for the last 40 years.
Are the ozone hole and global warming related?What can we do about global warming?What if global warming isn’t as severe as predicted?Why is global warming a problem?Has the Sun been more active in recent decades, and could it be responsible for some global warming?If Earth has warmed and cooled throughout history, what makes scientists think that humans are causing global warming now?How do scientists know that Mauna Loa’s volcanic emissions don’t affect the carbon dioxide data collected there?Do satellite observations of atmospheric temperatures agree with surface-based observations and model predictions?What does NASA have to do with global warming?Are there natural processes that can amplify or limit global warming?If we immediately stopped emitting greenhouses gases, would global warming stop?If we stabilized greenhouse gas emissions at today’s rates, would global warming stop?
by Stanley Falkow Fig. 1. Trouble jumping in? Source. A graduate student came to my office recently to say that she was increasingly bothered by anxiety and the ‘terror’ of having to speak at laboratory meetings.
Robert F. Kennedy Jr. is coming out with a new book that claims thimerosal in vaccines causes autism. This claim has been thoroughly discredited, but RFK Jr. believes that it's all a big conspiracy and that he's right. His crazy anti-vaccine views coupled with his fame make for an especially dangerous combination.
New Findings in Environmental Microbiology Described from Oak Ridge National Laboratory (Comparative metagenomic and rRNA microbial diversity characterization using archaeal and bacterial synthetic communities) By a News Reporter- Staff News Editor...
Two great trends are evident in the evolution of life on Earth: towards increasing diversification and towards increasing integration. Diversification has spread living processes across the planet, progressively increasing the range of environments and free energy sources exploited by life. Integration has proceeded through a stepwise process in which living entities at one level are integrated into cooperative groups that become larger-scale entities at the next level, and so on, producing cooperative organizations of increasing scale (for example, cooperative groups of simple cells gave rise to the more complex eukaryote cells, groups of these gave rise to multi-cellular organisms, and cooperative groups of these organisms produced animal societies). The trend towards increasing integration has continued during human evolution with the progressive increase in the scale of human groups and societies. The trends towards increasing diversification and integration are both driven by selection. An understanding of the trajectory and causal drivers of the trends suggests that they are likely to culminate in the emergence of a global entity. This entity would emerge from the integration of the living processes, matter, energy and technology of the planet into a global cooperative organization. Such an integration of the results of previous diversifications would enable the global entity to exploit the widest possible range of resources across the varied circumstances of the planet. This paper demonstrates that it's case for directionality meets the tests and criticisms that have proven fatal to previous claims for directionality in evolution.
The direction of evolution: The rise of cooperative organization John E. Stewart
Ecology as a science evolved from natural history, the observational study of the interactions of plants and animals with each other and their environments. As natural history matured, it became increasingly quantitative, experimental, and taxonomically broad. Focus diversified beyond the Eukarya to include the hidden world of microbial life. Microbes, particularly viruses, were shown to exist in unfathomable numbers, affecting every living organism. Slowly viruses came to be viewed in an ecological context rather than as abstract, disease-causing agents.
Many parasites commandeer the bodies of their hosts in order to spread. Examples of this include horsehair worms that reach water by forcing their cricket hosts to drown themselves, and liver flukes that drive infected ants to climb blades of grass, where cows can eat the insects, and so the flukes. But parasites can turn plants into zombies, too — and a team of scientists from the John Innes Centre in Norwich, UK, has now discovered how they do it.
When plants are infected by parasitic bacteria called phytoplasmas, their flowers turn into leafy shoots, their petals turn green and they develop a mass of shoots called ‘witches’ brooms’. This transformation sterilizes the plant, while attracting the sap-sucking insects that carry the bacteria to new hosts. “The plant appears alive, but it’s only there for the good of the pathogen,” says plant pathologist Saskia Hogenhout from the John Innes Centre in Norwich, UK. “In an evolutionary sense, the plant is dead and will not produce offspring.” “Many might baulk at the concept of a zombie plant because the idea of plants behaving is strange,” says David Hughes, a parasitologist at Pennsylvania State University in University Park. “But they do, and since they do, why wouldn't parasites have evolved to take over their behaviour, as they do for ants and crickets?”
National Post The anti-detox: 'Poo therapy' will replace cleanses, fashionable detoxes, US ... National Post However, scientists in the U.S. have come up with the “anti-detox” — a treatment that involves putting waste back in.
As member of the editorial board of Trends in Biotechnology, I thought it might be useful to identify the Trends in Biotechnology articles that generate the most buzz. Below are the articles that have been mentioned in social ...