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Researchers successfully assemble myrtle rust genome

April 01, 2020


A trans-Tasman research collaboration has successfully completed the assembly of a nearly complete genome for the fungus that causes myrtle rust. The task of assembling the genome was intensive and took many months because the Austropuccinia psidii genome is much larger than expected. In fact, it is by far the largest fungal genome assembled to date.

This work provides a valuable resource for research being undertaken to develop strategic approaches to combat disease spread.

The New Zealand contribution to this research was supported by Ministry for Primary Industries’ funding.

Read: Long-read assembly of the pandemic strain of Austropuccinia psidii (myrtle rust) reveals an unusually large (gigabase sized) and repetitive fungal genome

Also see this earlier research report about decoding the myrtle rust genome - Austropuccinia psidii De Novo sequencing    

Why assembly of the genome is important

Myrtle rust occurs when living plant tissue is infected by the fungus Austropuccinia psidii. Originally occurring only in South America where it is a natural part of the forest ecosystem, the fungus is now present in many places outside its native range and is recognised as a serious invasive plant pathogen around the world. It is known to infect at least 480 different species of plants in the large myrtle family, the Myrtaceae.

Several different strains of the fungus exist and the most widely distributed ‘pandemic biotype’ has been found throughout the Asia-Pacific and Oceania regions (including New Zealand) during the last 10 years.

Access to a complete genome is a critical resource for molecular and genomic studies into the ability of A. psidii to cause disease in host plants. The damage this disease causes to susceptible hosts can be devastating. Since 2010, when myrtle rust was first identified in Australia, it has caused the near extinction of at least three myrtle species, the decline of at least one keystone species, and negatively affected commercial production of economically important myrtles.

How the genome was assembled

The trans-Tasman collaboration successfully completed the assembly of a nearly complete genome for the pandemic biotype using sophisticated Single Molecule, Real-Time technology developed by American company PacBio, and spatial data obtained using Hi-C technology.

For more information on the technology used, follow the links below:

 

Assembling the genome by Peri Tobias University of Sydney

Photo credit: Peri Tobias