A Suppressor/Avirulence Gene Combination in Hyaloperonospora arabidopsidis Determines Race Specificity in Arabidopsis thaliana

Frontiers in Plant Science

David J. Studholme¹  Volkan Cevik²  Alison Woods-Tör³  Osman Telli³  Mahmut Tör³  Eric B. Holub⁴ 

[1] College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom;Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom;Institute of Science and the Environment, University of Worcester, Worcester, United Kingdom;Warwick Crop Centre, School of Life Sciences, University of Warwick, Coventry, United Kingdom;

关键词: effector;    avirulence inhibitor;    suppressor;    oomycete;    Arabidopsis;    downy mildew;   

DOI  :  10.3389/fpls.2018.00265

来源: DOAJ

【 摘 要 】

The pathosystem of Arabidopsis thaliana and diploid biotrophic oomycete Hyaloperonospora arabidopsidis (Hpa) has been a model for investigating the molecular basis of Flor's gene-for-gene hypothesis. The isolates Hpa-Noks1 and Hpa-Cala2 are virulent on Arabidopsis accession RMX-A02 whilst an F1 generated from a cross between these two isolates was avirulent. The F2 progeny segregated 3,1 (avirulent, virulent), indicating a single major effect AVR locus in this pathogen. SNP-based linkage mapping confirmed a single AVR locus within a 14 kb map interval containing two genes encoding putative effectors. The Hpa-Cala2 allele of one gene, designated H. arabidopsidiscryptic1 (HAC1), encodes a protein with a signal peptide and an RxLR/dEER motif, and triggers a defense response in RMX-A02. The second gene is heterozygous in Hpa-Cala2. One allele, designated Suppressor ofHAC1Cala2 (S-HAC1Cala2) encodes a protein with a signal peptide and a dKEE motif with no RxLR motif; the other allele (s-hac1Cala2) encodes a protein with a signal peptide, a dEEE motif and is divergent in sequence from the S-HAC1Cala2 allele. In selfed progeny from Hpa-Cala2, dominant S-HAC1Cala2 allele carrying progeny correlates with virulence in RMX-A02, whereas homozygous recessive s-hac1Cala2 carrying progeny were avirulent. Genetic investigations suggested other heterozygous suppressor loci might exist in the Hpa-Cala2 genome.

【 授权许可】

Unknown