Unlocking the genetic information of a fern could provide us potential solutions to multiple issues faced by our reikistjarna í dag.
In erfðamengi röðun, DNA sequencing is done to determine the order of nucleotides in every specific DNA molecule. This exact order is of value to be able to understand the type of genetic information carried in the DNA. Since genes encode for protein which are responsible for most body functions, this information can help to understand the effect of their function in the body. Sequencing complete erfðamengi of an organism i.e. all of its DNA is a complex and challenging task and has to be done bit by bit by breaking DNA into smaller pieces, sequencing them and then putting it all together. For example, the complete human erfðamengi was sequenced in 2003 took 13 years and a total cost of USD 3 billion. With advancement in technology erfðamengi can be sequenced relatively faster and at a lower cost using methods like Sanger sequencing and Next-generation sequencing. Once a genome is sequenced and decoded, unlimited possibilities open up for identifying potential areas of biological research and making progress towards targeted application development.
A team of 40 researchers from Cornell University and around the world have sequenced the full erfðamengi af vatni Fern kallaður Azolla filiculoides1,2. This fern is commonly seen to be growing in warmer temperatures and tropical regions of the world. The project of unravelling genomic secrets of the fern has been in the pipeline for a while and was backed by funds of USD 22,160 from 123 backers through a crowdfunding site called Experiment.com. Researchers eventually received funding to carry out the sequencing from Beijing Genomics Institute in collaboration with Utrecht University. This tiny floating fern species which fits over a finger nail has a genome size of .75 gigabases (or billion base pairs). Ferns are known to have large erfðamengi, average of 12 gigabases in size, however none of the larger fern genomes have been decoded so far. Such an elaborate project was aimed at providing clues on what could be the potential of this fern.
Many interesting aspects of fern Azolla have been uncovered upon this erfðamengi sequencing study published in Náttúruplöntur and have provided direction for future research on potential areas in which this fern can be beneficial. The fern Azolla was widespread and growing almost 50 million years ago on this reikistjarna around the Arctic Ocean. During that time Earth was also warmer compared to current conditions and this fern was thought to play a significant role in keeping the reikistjarna cooler by capturing around 10 trillion tons of carbon dioxide from the atmosphere over the course of 1 million years. Here we see a potential role for this fern in combating and protecting our reikistjarna from global warming resulted by climate change.
The fern is also thought to play an important role in nitrogen fixation, a process which combines free nitrogen (N2) in the atmosphere – an inert gas available abundantly in air – with other chemical elements to create more reactive nitrogen-based compounds e.g. ammonia, nitrates etc which can then be used in various applications like fertilizer for agriculture purposes. Erfðamengi data tells us about a symbiotic relationship (mutual benefit) of this fern with a cyanobacteria named Nostoc azollae. The fern leaf host these cyanobacteria in tiny holes and these bacteria fix nitrogen thereby producing súrefni sem ferninn og nærliggjandi vaxandi plöntur gætu notað. Aftur á móti blýantur bakteríur gather energy through the plant photosynthesis when the fern provides it fuel. Therefore, this fern could be possibly used as a natural green fertilizer and possibly eliminate usage of nitrogen fertilizers propagating more sustainable agricultures practises. Authors say that having both the erfðamengi of cyanobacteria and now the fern, research can be focused on developing and adopting such sustainable practises. Interestingly, fern Azolla has already been added in rice paddies as green manure by Asian farmers for more than 1000 years.
Vísindamenn hafa einnig greint mikilvægt náttúrulega breytt (skordýraeitur) gen í fernunni sem sést hafa getu til að veita skordýraþol. Þetta gen veitir gríðarlega vernd gegn skordýrum þegar það er flutt yfir í bómullarplöntur. Talið er að þetta „skordýraeitur“ gen sé flutt eða „gefið“ frá bakteríum yfir á fernuna og er talið vera mjög sérstakur hluti af ætt fernunnar, þ.e. það hefur borist með góðum árangri frá kynslóð til kynslóðar. Uppgötvun mögulegrar verndar gegn skordýrum hlýtur að hafa mikil áhrif á landbúnaðarhætti.
This study shows that ‘pure science’ of unravelling first ever genomic information from ferns is a major step in the direction of uncovering and understanding crucial plant genes. It also helps in a better understanding of the evolutionary history of ferns i.e. how their features have evolved over the generations. Understanding of plants is very crucial to explore and comprehend how flora and fauna exist together amicably on our reikistjarna and such research should be given importance rather than labelling it as something which is not significant enough. After sequencing Azolla filiculoides and Salvinia cucullata, more than 10 fern species are already in pipeline for further research.
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{Þú getur lesið upprunalegu rannsóknarritgerðina með því að smella á DOI hlekkinn sem gefinn er upp hér að neðan á listanum yfir tilvitnaðar heimildir}
Heimildir)
1. Fay-Wei L et al. 2018. Fern erfðamengi elucidate land plant evolution and cyanobacterial symbioses. Náttúruplöntur. 4 (7). https://doi.org/10.1038/s41477-018-0188-8
2. Fernbase https://www.fernbase.org/. [Skoðað 18. júlí 2018].
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