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What is the context of this research?

Fifty million years ago, the Earth was so warm that much of the North Pole was covered with the floating fern Azolla. Arctic Ocean sediments from this time are composed almost entirely of Azolla fossils for an 800,000-year span: an interval called the Arctic Azolla event. As these Azolla plants died and became part of the sediment, they took atmospheric carbon down with them. Global atmospheric levels of CO2 fell significantly, precipitating Earth's initial shift from a greenhouse world towards the current icehouse climate that we're now worried will melt. Azolla is still with us, floating on the surface of ponds and lakes. Tiny, but fierce, it can double its entire body mass in just less than two days––a promising alternative for biofuel production and carbon-capture efforts.

What is the significance of this project?

Azolla does another interesting trick–it captures all the nitrogen fertilizer it needs from the atmosphere around it. Asia’s farmers have long known about this, growing Azolla together with rice. Azolla fixes nitrogen, improves the soil, and provides a natural fertilizer to bolster rice productivity. Azolla isn't just a plant; it’s a ‘superorganism,’ a symbiotic collaboration of a plant and a microbe. In a special leaf cavity, Azolla hosts a microbe called Nostoc that converts atmospheric nitrogen into food for its host. Azolla and Nostoc can combat global warming and produce precious nitrogen to help feed the world. Wouldn't it be great to understand this symbiotic relationship better? To be able to decipher the biological "conversation" between the host and the microbe?

What are the goals of the project?

Our goal is to unlock this superorganism’ superpowers and better adapt the Azolla system to agricultural, biofuel, and carbon sequestration applications.

We will develop a genomic resource for Azolla. Among the five major plant lineages, the only one without a sequenced genome is ferns. This first fern genome will not only provide an accurate framework to examine patterns underlying evolutionary transitions in land plants, but also a critical resource for nitrogen fixation, biofuel production and symbiosis research.

We will also use metagenomics to comprehensively explore the microbial diversity and functional repertoire associated with Azolla. We will focus on gene families and biological pathways involved in nitrogen utilization and a symbiotic lifestyle.



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