Evolutionary Genetics

Most plants face attacks by fungal pathogens. In agriculture, outbreaks of diseases are frequent and pose a significant threat to sustainable food production. What enables pathogens to overcome host defenses and cause damage is poorly understood. A key evolutionary step for pathogens is to evolve effectors that specifically target and disable the plant immune system.

Our group uses experimental and population genomics tools to analyze the rapid emergence of pathogens. A major focus is to use genome-wide association studies (GWAS) to directly identify the genes in pathogen genomes linked to the breakdown of host resistance. We also assemble complete genomes to analyze mechanisms that generate high degrees of sequence polymorphism. We are particularly interested in the action of transposable elements (selfish elements in the genome) and the evolution of gene regulation. Our group also conducts population genomic studies to analyze the process of adaptive evolution in natural field populations.

• The emergence of the multi-species NIP1 effector in Rhynchosporium was accompanied by high rates of gene duplications and losses
  Mohd-Assaad, N; McDonald, BA; Croll, D
  ENVIRONMENTAL MICROBIOLOGY, 21 (8):2677-2695; 10.1111/1462-2920.14583 AUG 2019
• Cautionary Notes on Use of the MoT3 Diagnostic Assay for Magnaporthe oryzae Wheat and Rice Blast Isolates
  Gupta, DR; Avila, CSR; Win, J; Soanes, DM; Ryder, LS; Croll, D; Bhattacharjee, P; Hossain, MS; Mahmud, NU; Mehebub, MS; Surovy, MZ; Rahman, MM; Talbot, NJ; Kamoun, S; Islam, MT
  PHYTOPATHOLOGY, 109 (4):504-508; 10.1094/PHYTO-06-18-0199-LE APR 2019
• Wheat blast: from its origins in South America to its emergence as a global threat
  Ceresini, PC; Castroagudin, VL; Rodrigues, FA; Rios, JA; Aucique-Perez, CE; Moreira, SI; Croll, D; Alves, E; de Carvalho, G; Maciel, JLN; McDonald, BA
  MOLECULAR PLANT PATHOLOGY, 20 (2):155-172; 10.1111/mpp.12747 FEB 2019
• Rapid Parallel Evolution of Azole Fungicide Resistance in Australian Populations of the Wheat Pathogen Zymoseptoria tritici
  McDonald, MC; Renkin, M; Spackman, M; Orchard, B; Croll, D; Solomon, CPS; Milgate, A
  APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 85 (4):10.1128/AEM.01908-18 FEB 2019
• The birth and death of effectors in rapidly evolving filamentous pathogen genomes
  Fouche, S; Plissonneau, C; Croll, D
  CURRENT OPINION IN MICROBIOLOGY, 46 34-42; 10.1016/j.mib.2018.01.020 DEC 2018
• The Monothiol Glutaredoxin Grx4 Regulates Iron Homeostasis and Virulence in Cryptococcus neoformans
  Attarian, R; Hu, GG; Sanchez-Leon, E; Caza, M; Croll, D; Do, E; Bach, H; Missall, T; Lodge, J; Jung, WH; Kronstad, JW
  MBIO, 9 (6):10.1128/mBio.02377-18 NOV-DEC 2018
• Wheat Blast: Past, Present, and Future
  Ceresini, PC; Castroagudin, VL; Rodrigues, FA; Rios, JA; Aucique-Perez, CE; Moreira, SI; Alves, E; Croll, D; Maciel, JLN
  Edited by: Leach JE; Lindow SE
  ANNUAL REVIEW OF PHYTOPATHOLOGY, VOL 56, 56 427-456; 10.1146/annurev-phyto-080417-050036 2018
• The Genome Biology of Effector Gene Evolution in Filamentous Plant Pathogens
  Sanchez-Vallet, A; Fouche, S; Fudal, I; Hartmann, FE; Soyer, JL; Tellier, A; Croll, D Edited by: Leach JE; Lindow SE
  ANNUAL REVIEW OF PHYTOPATHOLOGY, VOL 56, 56 21-40; 10.1146/annurev-phyto-080516-035303 2018
• Genomewide signatures of selection in Epichloe reveal candidate genes for host specialization
  Schirrmann, Melanie K; Zoller, Stefan; Croll, Daniel; Stukenbrock, EH; Leuchtmann, A; Fior, S
  MOLECULAR ECOLOGY   Volume: 27   Issue: 15   Pages: 3070-3086 10.1111/mec.14585 AUG 2018
• Genome-Wide Detection of Genes Under Positive Selection in Worldwide Populations of the Barley Scald Pathogen
  Mohd-Assaad, N; McDonald, BA; Croll, D
  GENOME BIOLOGY AND EVOLUTION, 10 (5):1315-1332; 10.1093/gbe/evy087 MAY 2018
• Meiosis Leads to Pervasive Copy-Number Variation and Distorted Inheritance of Accessory Chromosomes of the Wheat Pathogen Zymoseptoria tritici
  Fouche, S; Plissonneau, C; McDonald, BA; Croll, D
  GENOME BIOLOGY AND EVOLUTION, 10 (6):1416-1429; 10.1093/gbe/evy100 JUN 2018
• A fungal avirulence factor encoded in a highly plastic genomic region triggers partial resistance to septoria tritici blotch
  Meile L; Croll D; Brunner PC; Plissonneau C; Hartmann FE; McDonald BA; Sanchez-Vallet A
  NEW PHYTOLOGIST   Volume: 219   Issue: 3 1048-1061 10.1111/nph.15180   AUG 2018
• Transposable element insertions shape gene regulation and melanin production in a fungal pathogen of wheat
  Krishnan, Parvathy; Meile, Lukas; Plissonneau, Clemence; Ma, Xin; Hartmann, Fanny E; Croll, Daniel; McDonald, Bruce A; Sanchez-Vallet, Andrea
  BMC BIOLOGY   Volume: 16(78)  10.1186/s12915-018-0543-2  JUL 16 2018

• Genetic basis of pathogen virulence
• Ecological genomics and local adaptation of pathogens
• Population genomics of pathogen outbreaks
• Structure and evolution of pathogen genomes
• Transposable elements and the evolution of gene regulation

• Crop resistance breeding
• Bioinformatics and genome assembly
• Molecular plant pathology
• Fungal community analyses
• Genome-wide association mapping (GWAS)