#9 Plant-Insect Gene Transfer, Iron in Astrobiology and Oxygen Made in the Dark...
Gene transfer between plants and whiteflies, iron in the origin of life and the potential of life in space as well as oxygen being produced - not through photosynthesis...
🧬Plant or Insect DNA?
A Plant gene found in Insects can shield the aphid from toxins…
Millions of years ago, whiteflies incorporated a portion of DNA from plants into their genomes. It has recently been revealed that this DNA has aided the insect in a specialised way. One of the stolen genes can be utilised to degrade common toxins that plants use to defend themselves against the whiteflies. Possessing the gene has allowed the whitefly to feed off the plants safely as a result.
This is believed to be the first recorded example of horizontal gene transfer between a plant and an Insect. The gene that was successfully transferred, responsible for neutralizing toxic compounds produced from the plant, named BtPMaT1, has not been found in other insect species.
The BtPMaT1 genes role is to aid in the storing of the toxin, safely, within the plant. Youjun Zhang and his team, used a combination of both phylogenetic and genetic analyses to discover that around 35 million years ago, a virus may have transferred the gene from the plant to the whitefly insect. The virus within the plant may have taken in the gene. The whitefly then ingested the plant, and resultantly managed to incorporate the DNA into its genome. Whilst this was an unlikely event, over millions of years, billions of individual insects, viruses and plants across a long time period, there is a chance that an event such as this could occur.
Since this event occurred, whiteflies have become a major agricultural pest worldwide, with an ability to attack at least 600 different species of plants across the world. Following the discovery, Chinese colleagues created a strategy to reverse the whiteflies accidentally stolen “superpower”. The Chinese team developed a small RNA molecule that interferes with the BtPMaT1 gene, altering its expression and making the whiteflies susceptible to the toxin released by the Plant.
Turling, the co author of the study, went on to say that “the most exciting step of this design was when our colleagues genetically manipulated tomato plants to start producing this RNA molecule". Therefore, once the whiteflies had ingested the plant and so ingested the plant-produced RNA, the BtPMaT1 gene was silenced, resulting in complete mortality of the insect. Furthermore, the genetic manipulation had no negative impact on the survival of other insects tested.
This shows promise for the future with specific efforts to produce genetically modified crops that are able to silence the whitefly gene, a targeted agricultural pest control method could be implemented. Whilst there are still numerous hurdles for the team to face, including ethical scepticism and the publics view on the matter, the research so far is indicative of success in the area with numerous potential future applications.
🏌️Iron a Driver of Evolution?
The importance of Iron in how our world started and how we may discover others…
Iron is an essential nutrient that is integral to life as we know it. Iron played an important role in the Formation of Earth, with the fixed amount in our rock mantle being key in the exact function and development of life. Scientists at Oxford University have revealed the possible mechanisms by which iron could have influenced the development of complex life forms.
Co-author Jon Wade, an Associate Professor of Planetary Materials at the Department of Earth Sciences in Oxford, said that the “initial amount of iron in Earth’s rocks is “set” by the conditions of planetary accretion, during which the Earth’s metallic core segregated from its rock mantle”. “Too little iron in the rocky portion of the planet, like the planet Mercury, and life is unlikely. Too much, like Mars, and water may be difficult to keep on the surface for times relevant to the evolution of complex life.”
Initially, the iron conditions on Earth would have been optimal. This would have meant that there was surface retention of water. Iron was soluble in sea water, meaning that it was easily available to enable simple life forms to develop. Roughly 2.4 billion years ago oxygen levels on Earth began to rise which was termed the “Great Oxygenation Event”. The increasing levels of oxygen created a reaction with the Iron, resulting in the iron becoming insoluble. This meant that gigatons (1 billion tonnes) of iron dropped out of the sea water, and so it was less available to developing life forms.
“Life had to find new ways to obtain the iron it needs,” stated co author Hal Drakesmith, Professor of Iron Biology at the MRC Weatherall Institute of Molecular Medicine, University of Oxford. He went on to say that “For example, infection, symbiosis and multicellularity are behaviours that enable life to more efficiently capture and utilise this scarce but vital nutrient. Adopting such characteristics would have propelled early life forms to become ever more complex, on the way to evolving into what we see around us today.”
It is unknown how common intelligent life is in the Universe. The concepts shown in the research show that conditions required to support the initial stages of life and development of simple life forms, are different to those of complex life forms and intelligent organism evolution. The temporal changes as seen on Earth which allowed life to find new ways of accessing iron, may be rare or random, meaning that the likelihood of intelligent life on other plants is unlikely.
However as with all astrobiology, knowing more about how important specific nutrients such as iron were in the development of early life, may help the search for suitable planets that could develop life forms. Research such as this by Oxford University, may be crucial in the search of life supporting exoplanets.
🦠Microbes Produce Oxygen in the Dark?
Oxygen can also be produced in the dark without photosynthesis…
The study from the University of Southern Denmark looked at the ammonia oxidizing archaea and how this group of microbes have the ability to make oxygen without sunlight. Oxygen is obviously a key element for life on Earth, and is mostly produced by plants, cyanobacteria and algae through the process of photosynthesis. Whilst the scientific community are aware of a few microbes that are known to make oxygen without sunlight, their knowledge and discovery has been limited to smaller quantities, in specific habitats.
The ocean living microbe named Nitrosopumilus Maritimes and the species cousins, are known as the ammonia oxidizing archaea. They are an abundant species in the ocean where they are key in numerous processes including the nitrogen cycle. Due to their role they need oxygen, and as a result it has been a point of confusion amongst scientists as to why they are so abundant in waters with no oxygen, with previous theories believing that they held no function in these locations and were a type of “ghost cell”.
Don Canfield, Co-author of the paper stated that “These microbes are so common, that every 5th cell in a bucket of seawater is one of them”. The researchers reached the conclusion that they made their own oxygen. "We wanted to see what would happen if they ran out of oxygen -- like they do when they move from the oxygen rich waters to oxygen depleted waters." "We saw how they used up all the oxygen in the water, and then to our surprise, within minutes, oxygen levels started increasing again. That was very exciting!," said Don Canfield.
However, they are not capable of battling plants in terms of oxygen production. Whilst Nitrosopumilus Maritimes produce oxygen, and do so in a dark environment, they produce only enough to keep themselves going, and not to an extent that would influence levels on Earth. Producing more oxygen would result in other marine based organisms occupying the area and consuming the excess resource, resultantly meaning that no oxygen would leave the ocean.
Researchers of the study were aware of the ammonia oxidizing archaea’s ability to keep the global nitrogen cycle going, however were not aware of the full extent of their capabilities. In a recent discovery, the Nitrosopumilus Maritimes species is found to couple the oxygen production to that of gaseous nitrogen and in doing so, remove bioavailable nitrogen from the localised environment. Should further research reveal that this coupled pathway occurs on larger spatial scale, it will change our current understanding of the marine nitrogen cycle.
The research team co led by Beate Kraft has already taken samples in Denmark with plans to sample the Mexican and Costa Rican coasts in the near future.
Weekly Topics
🏞️ Environmental
The impacts of water conservation on fish habitat and ecobiology in the Yangtze River
Stables become rare bat maternity ward
Coral skeletons may store microplastic
🐼 Conservation
The path to real conservation gains
Environmental conservation in Mexico
Beavers support freshwater conservation and ecosystem stability
🦠 Disease and Illness
Exercise changes the brain chemistry to protect synapses
mRNA vaccine may offer protection against tick-borne diseases
Testosterone replacement therapy and erectile dysfunction
😷 COVID
US virus increase and 25% 24 hour drop…
Closes known relatives of virus behind COVID19 found
How scientists detect new COVID variants
🧪 Biochemistry
Innovations in disease testing - Utilising pandemic technologies for the future
One cell - two genomes? Coordination between mitochondria and the nucleus in cancer
Interview - Could the delta variant evade vaccine-induced immunity?
🔬 Evolution
Common origin - snake venom and mammalian saliva
New timeline of mammal evolution
🧬 Genetics
How active DNA molecules with therapeutic potential work
CAR T Cells restore cardiac function in heart failure mice patients…
Zoo study finds Animal DNA floating in the air
📷 Weekly Camera Roll
Click on the text below to keep reading…
Thank you for reading another issue of the BioSnip newsletter. Please consider sharing!
🔗Reference List
🧬Plant or Insect DNA
Cell Press. (2021, March 25). Plant gene found in insect, shields it from leaf toxins. ScienceDaily. Retrieved January 8, 2022 from www.sciencedaily.com/releases/2021/03/210325145905.htm
Jixing Xia, Zhaojiang Guo, Zezhong Yang, Haolin Han, Shaoli Wang, Haifeng Xu, Xin Yang, Fengshan Yang, Qingjun Wu, Wen Xie, Xuguo Zhou, Wannes Dermauw, Ted C.J. Turlings, Youjun Zhang. Whitefly hijacks a plant detoxification gene that neutralizes plant toxins. Cell, 2021; DOI: 10.1016/j.cell.2021.02.014
🏌️Iron a Driver of Evolution?
Iron Integral to the Development of Complex Life on Earth – And the Possibility of Life on Other Planets. SciTechDaily. https://scitechdaily.com/iron-integral-to-the-development-of-complex-life-on-earth-and-the-possibility-of-life-on-other-planets/
“Temporal variation of planetary iron as a driver of evolution” by Jon Wade, David J. Byrne, Chris J. Ballentine and Hal Drakesmith, 6 December 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2109865118
🦠Microbes Produce Oxygen in the Dark?
Microbes produce oxygen in the dark. PHYSORG. https://phys.org/news/2022-01-microbes-oxygen-dark.html
Beate Kraft, Oxygen and nitrogen production by an ammonia-oxidizing archaeon, Science (2022). DOI: 10.1126/science.abe6733. www.science.org/doi/10.1126/science.abe6733