Telomere hypervariability in the rice blast fungus Magnaporthe oryzae, a model plant pathogen

The research performed in this project was the first to investigate the molecular basis of telomere instability and, as such, represents a landmark study. Highlights include: identification of five different mechanisms for telomere rearrangements; discovery of a new mode of fungal genome evolution – namely telomere internalization; and demonstration that telomeric transposons rescue telomerase-minus cells from telomere crisis. The project provided training to two postdocs and a visiting scientist and supported the research of a graduate student. Eight undergraduate students (including two minority females) gained research experience – three through the REU program.

Research findings:

1. Telomere instability in Magnaporthe occurs via several mechanisms:
2. Telomere instability promotes genome rearrangement through “telomere internalization”
3. MoTeRs rescue Magnaporthe from the telomere crisis that normally results from telomerase deletion.
4. Telomere Instability in Magnaporthe isolates lacking MoTeRs – an apparent example of “Adaptive Telomere Failure.”

Broader Impacts:

This project provided undergraduate research training for one graduate student and five undergraduates.

Students

Rahnama, Mostafa - Post-Doctoral Scholar, Added 06/17/2020 on LCC

April E Lamb, Graduate, Added 02/01/2021

Alexander Stewart, Added 07/08/2021

Collaborators

Software

Software developed for telomere identification and assembly were shared with numerous research labs.

Grants

KSEF-148-502-14-337 Exploring a Novel Mechanism for Pathogenic Adaptation in Fungi KY Science and Technology Co Inc 7/1/2014 - 6/30/2015 $30,000
S13166 Novel Strategies for Managing Blast Diseases on Rice and Wheat Kansas State University 1/1/2013 - 12/31/2015 $196,098
MCB-0653930, $357,000, 3/1/2007 - 2/29/2012 (N.C.E.) Telomere hypervariability in the rice blast fungus Magnaporthe oryzae

Publications:

1. Schardl C, Young C, Hesse U, Amyotte S, Andreeva K, Calie P, Fleetwood D, Haws D, Schweri K, Moore N, Oeser B, Voisey C, Farman M and 41 others (2013) Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid loci, PLoS Genetics 9: e1003323
2. Farman M, Novikova OS, Starnes JH, Thorbury DW. 2014. Subtelomere organization, evolution, and dynamics in the rice blast fungus Magnaporthe oryzae. In Subtelomeres, (ed. EJ Louis, MM Becker), pp. 71-99. Springer-Verlag, Berlin, Heidelberg.
3. Starnes J, Thornbury D, Rehmeyer C and Farman M (2012). Telomere-targeted non-LTR retrotransposons in Magnaporthe oryzae: agents of genome instability. Genetics. 191:389-406
4. Farman M (2011) Targeted cloning of fungal telomeres. Meth. Mol. Biol. 722:11-31.
5. Schwartz S and Farman M (2010) Systematic overrepresentation of DNA ends and underrepresentation of DNA termini among sequencing templates prepared from hydrodynamically sheared DNA molecules. BMC Genomics 11: 87.
6. Wu, C, Kim Y-S, Smith K, Li W, Hood H, Staben C, Selker E, Sachs M, and Farman M (2009) Characterization of chromosome ends in the filamentous fungus Neurospora crassa. Genetics 181: 1129-1145.
7. Rehmeyer C, Li W, Kusaba M, and Farman M (2009) The telomere-linked helicase (TLH) gene family in Magnaporthe oryzae: Revised gene structure reveals a novel TLH-specific protein domain. Current Genetics 55:253-262.

C.2 Other products: Genbank submissions, FJ589751 - FJ589764, FJ597629 - FJ597638, FJ867915 - FJ867918.