Genome-enabled discovery of candidate virulence loci in Striga hermonthica, a devastating parasite of African cereal crops.

Autor: Qiu S; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK., Bradley JM; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK., Zhang P; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK., Chaudhuri R; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK., Blaxter M; Institute of Evolutionary Biology, School of Biological Sciences, The University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK.; Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK., Butlin RK; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.; Department of Marine Sciences, University of Gothenburg, S-405 30, Gothenburg, Sweden., Scholes JD; School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2022 Oct; Vol. 236 (2), pp. 622-638. Date of Electronic Publication: 2022 Jul 07.
DOI: 10.1111/nph.18305
Abstrakt: Parasites have evolved proteins, virulence factors (VFs), that facilitate plant colonisation, however VFs mediating parasitic plant-host interactions are poorly understood. Striga hermonthica is an obligate, root-parasitic plant of cereal hosts in sub-Saharan Africa, causing devastating yield losses. Understanding the molecular nature and allelic variation of VFs in S. hermonthica is essential for breeding resistance and delaying the evolution of parasite virulence. We assembled the S. hermonthica genome and identified secreted proteins using in silico prediction. Pooled sequencing of parasites growing on a susceptible and a strongly resistant rice host allowed us to scan for loci where selection imposed by the resistant host had elevated the frequency of alleles contributing to successful colonisation. Thirty-eight putatively secreted VFs had very different allele frequencies with functions including host cell wall modification, protease or protease inhibitor and kinase activities. These candidate loci had significantly higher Tajima's D than the genomic background, consistent with balancing selection. Our results reveal diverse strategies used by S. hermonthica to overcome different layers of host resistance. Understanding the maintenance of variation at virulence loci by balancing selection will be critical to managing the evolution of virulence as part of a sustainable control strategy.
(© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.)
Databáze: MEDLINE
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