Identifcation of genotypescarriers of resistance to tan spot Ptr ToxA and Ptr ToxB of Pyrenophora tritici-repentis in common wheat collection

Pyrenophora tritici-repentis (Ptr) is the causative agent of tan spot, one of the yield limiting diseases of wheat, rapidly increasing in wheat growing countries including Kazakhstan. The aim of this study was the identifcation of wheat genotypes with resistance to Ptr race 1 and race 5 and their host­selective effectors (toxins) Ptr ToxA and Ptr ToxB. A common wheat collection of 41 accessions (38 experimental and 3 controls) was characterized using the molecular markers Xfcp623 and XBE444541, diagnostic for the Tsn1 and Tsc2 genes conferring sensitivity to fungal toxins. The coincidence of the marker XBE444541 with resistance to race 5 was 92.11 %, and with Ptr ToxB, 97.37 %. Genotyping results using the marker Xfcp623 confrmed the expected response to Ptr ToxA; the presence/absence of the marker Xfcp623 completely (100 %) coincided with sensitivity/resistance to race 1 and Ptr ToxA. This demonstrates the reliability of the diagnostic marker Xfcp623 for identifying wheat genotypes with resistance to the fungus and insensitivity to Ptr ToxA. The study of the reaction of wheat germplasm to the fungal inoculation and toxin infltration showed that out of 38 genotypes analyzed 30 (78 %) exhibited resistance to both race 1 and race 5, and insensitivity to toxins Ptr ToxA and ToxB. Of most signifcant interest are eight wheat genotypes that showed resistance/insensitivity both to the two races and two toxins. The results of phenotyping were reconfrmed by the molecular markers used in this study. Sensitivity to Ptr ToxB is not always correlated with susceptibility to race 5 and is dependent on the host’s genetic background of the wheat genotype, i. e. on a specifc wheat genotype. The results of the study are of interest for increasing the efciency of breeding based on the elimination of the genotypes with the dominant alleles Tsn1 and Tsc2 sensitive to the toxins Ptr ToxA and ToxB. The genotypes identifed will be used in wheat breeding for resistance to tan spot.

1. Gultyaeva E.I., Kovalenko N.M., Shamanin V.P., Tyunin V.A., Shreyder E.R., Shaydayuk E.L., Morgunov A.I. Population structure of leaf pathogens of common spring wheat in the West Asian regions of Russia and Northern Kazakhstan in 2017. Vavilovskii Zhurnal Genetiki i Selektsii = Vavilov Journal of Genetics and Breeding. 2018;22(3):363-369. DOI 10.18699/VJ18.372. (in Russian)

2. Koyshibaev M.K. Diseases of Plants. Almaty, 2002. (in Russian)

3. Kokhmetova A.M., Kremneva O.Yu., Keyshilov Zh.S., Sultanova N.Zh. Race range and virulence of Pyrenophora tritici-repentis isolates in the Republic of Kazakhstan and the North Caucasus region of Russia. Eurasian J. Appl. Biotechnol. 2016;3:57-66. (in Russian)

4. Mironenko N.V., Kovalenko N.M. Interaction of the Tsn1 and ToxA genes in the Triticum aestivum – Pyrenophora tritici-repentis pathosystem. Vestnik Zaschity Rasteniy = Plant Protection News. 2018; 2(96):12-16. (in Russian)

5. Mihaylova L.A., Mironenko N.V., Kovalenko N.M. Tan Spot of Wheat. Guidelines for the study of populations of the tan spot causative agent Pyrenophora tritici-repentis and resistance of varieties. St. Petersburg, 2012. (in Russian)

6. Pospekhov G.V. Features of the growth and fruiting of the cultured fungus Pyrenophora tritici-repentis (Died.) Drechs. Mikologia i Fitopatologia = Mycology and Phytopathology.1989;23(2):117-121. (in Russian)

7. Sultanova N.Zh. Biological features of the causative agent of tan spot of winter wheat leaves in southeastern Kazakhstan. Vestnik Selskokhozyaystvennoy Nauki Kazakhstana = Bulletin of Agricultural Sciences of Kazakhstan. 2007;3:4-6. (in Russian)

8. Chesnokov V.A., Bazyrina E.N., Bushueva T.M., Il’inskaja N.L. Growing of Plants without Soil. Leningrad, 1960. (in Russian)

9. Abeysekara N.S., Friesen T.L., Liu Z., McClean P.E., Faris J.D. Marker development and saturation mapping of the tan spot Ptr ToxB sensitivity locus Tsc2 in hexaploid wheat. Plant Genome. 2010;3:179- 189. DOI 10.3835/plantgenome2010.07.0017.

10. Ali S., Gurung S., Adhikar T.B. Identifcation and characterization of novel isolates of Pyrenophora tritici-repentis from Arkansas. Plant Dis. 2010;94:229-235. DOI 10.1094/pdis-94-2-0229.

11. Anderson J.A., Effertz R.J., Faris J.D., Francl L.J., Meinhardt S.W., Gill B.S. Genetic analysis of sensitivity to a Pyrenophora triticirepentis necrosis¬inducing toxin in durum and common wheat. Phytopathology. 1999;89:293-297.

12. Andrie R.M., Pandelova I., Ciuffetti I.M. A combination of phenotypic and genotypic characterization strengthens Pyrenophora tritici-repentis race identifcation. Phytopathology. 2007;97:694-701.

13. Ballance G.M., Lamari L., Bernier C.C. Purifcation and characterization of a host¬selective necrosis toxin from Pyrenophora tritici-repentis. Physiol. Mol. Plant Pathol. 1989;35:203-213.

14. Chen X., Line R., Leung H. Genome scanning for resistance gene analogs in rice, barley, and wheat by high resolution electrophoresis. Theor. Appl. Genet. 1998;97:345-355.

15. Chu C.G., Friesen T.L., Faris J.D., Xu S.S. Evaluation of seedling resistance to tan spot and Stagonospora nodorum blotch in tetraploid wheat. Crop Sci. 2008;48:1107-1116. DOI 10.2135/cropsci2007.09.0516.

16. Cook R.J., Yarham D.J. Occurrence of tan spot of wheat caused by Pyrenophora tritici-repentis on wheat in England and Wales in 1987. Plant Pathol. 1989;38(1):101-102. DOI 10.1111/j.1365-3059.1989.tb01434.x.

17. Dinglasan E.G., Godwin I.D., Phan H.T.T., Tan K.-C., Platz G.J., Hickey L.T. Vavilov wheat accessions provide useful sources of resistance to tan spot (syn. yellow spot) of wheat. Plant Pathol. 2018; 67(5):1076-1087. DOI 10.1111/ppa.12822.

18. Dumitras L., Bontea V. Data noi privinol parasitul foliar al griulu Helminthosporium repentis Diedicke. Studii si Cercetari de Biologie Vegetala. 1981;33:169-172.

19. Faris J.D., Zhang Z., Lu H., Lu S., Reddy L., Cloutier S., Fellers J.P., Meinhardt S.W., Rasmussen J.B., Xu S.S., Oliver R.P., Simons K.J., Friesen T.L. A unique wheat disease resistance-like gene governs effector-triggered susceptibility to necrotrophic pathogens. Proc. Natl. Acad. Sci. USA. 2010;107:13544-13549. DOI 10.1073/pnas.1004090107.

20. Faris J.D., Zhang Z., Rasmussen J.B., Friesen T.L. Tan spot susceptibility governed by the Tsn1 locus and race nonspecifc resistance quantitative trait loci in a population derived from the wheat lines Salamouni and Katepwa. Mol. Breed. 2012;30:1669-1678. DOI 10.1007/s11032-012-9750-7.

21. Friesen T.L., Faris J.D. Molecular mapping of resistance to Pyrenophora tritici-repentis race 5 and sensitivity to Ptr ToxB in wheat. Theor. Appl. Genet. 2004;109:464-471. DOI 10.1007/s00122-004-1678-9.

22. Kariyawasam G.K., Carter A.H., Rasmussen J.B., Faris J.D., Xu S.S., Mergoum M., Liu Z. Genetic relationships between race-nonspecifc and race specifc interactions in the wheat-Pyrenophora tritici-repentis pathosystem. Theor. Appl. Genet. 2016;129:897-908. DOI 10.1007/s00122-016-2670-x.

23. Kokhmetova A., Kremneva O., Volkova G., Atishova M., Sapakhova Z. Evaluation of wheat cultivars growing in Kazakhstan and Russia for resistance to tan spot. J. Plant Pathol. 2017;99(1):161-167. DOI 10.4454/jpp.v99i1.3812.

24. Kollers S., Rodemann B., Ling J., Korzun V., Ebmeyer E., Argillier O., Hinze M., Plieske J., Kulosa D., Gana M.W., Roder M.S. Genomewide association mapping of tan spot resistance (Pyrenophora tritici-repentis) in European winter wheat. Mol. Breed. 2014;34(2):363- 371. DOI 10.1007/s11032-014-0039-x.

25. Lamari L., Bernier C.C. Evalution of wheat lines and cultivars to tan spot [Perynophora tritici-repentis] based on lesion type. Can. J. Plant Sci. 1989;11(1):49-56.

26. Lamari L., Bernier C.C. Genetics of tan necrosis and extensive chlorosis in tan spot of wheat caused by Pyrenophora tritici-repentis. Phytopathology. 1991;81:1092-1095.

27. Lamari L., Strelkov S.E., Yahyaoui A., Amedov M., Saidov M., Djunusova M., Koichibayev M. Virulence of Pyrenophora tritici-repentis in the countries of the Silk Road. Can. J. Plant Pathol. 2005; 27:383-388. DOI 10.1080/07060661.2012.695750.

28. Lamari L., Strelkov S.E., Yahyaoui A., Orabi J., Smith R.B. The identifcation of two new races of Pyrenophora tritici-repentis from the host center of diversity confrms a one-to-one relationship in tan spot of wheat. Phytopathology. 2003;93(4):391-396. DOI 10.1094/phyto.2003.93.4.391.

29. Lu H.J., Faris J.D. Macro- and microcolinearity between the genomic region of wheat chromosome 5B containing the Tsn1 gene and the rice genome. Funct. Integr. Genomics. 2006;6(2):90-103. DOI 10.1007/s10142-005-0020-1.

30. Maraite H., Berny J.F., Goff A. Epidemiology of tan spot in Belgium. Proc. of the 2nd Int. Tan Spot Workshop. Fargo, North Dakota State Univ., 1992;73-79.

31. Maraite H., Mercado-Vergnes D., Renard M.-E., Zhanarbekova A., Duveiller E. Relevance of pathogen diversity in management of leaf spot and leaf blight diseases on wheat in Central Asia. Agromeridian. 2006;2:105-114.

32. Martinez J.P., Oesch N.W., Ciuffetti L.M. Characterization of the multiple-copy host-selective toxin gene, ToxB, in pathogenic and nonpathogenic isolates of Pyrenophora tritici-repentis. Mol. Plant Microbe Interact. 2004;17:467-474. DOI 10.1094/MPMI.2004.17.5.467.

33. Martinez J.P., Ottum S.A., Ali S., Francl L.J., Ciuffetti L.M. Characterization of the ToxB gene from Pyrenophora tritici-repentis. Mol. Plant Microbe Interact. 2001;14:675-677. DOI 10.1094/mpmi.2001.14.5.675.

34. Orolaza N.P., Lamari L., Ballance G.M. Evidence of a hostspecifc chlorosis toxin from Pyrenophora tritici-repentis, the causal agent of tan spot of wheat. Phytopathology. 1995;85:1282-1287.

35. Rees R.G., Platz G.J., Mayer R.J. Susceptibility of Australian wheats to Pyrenophora tritici-repentis. Aust. J. Agric. Res. 1988;39:141-151.

36. Riede C.R., Anderson J.A. Linkage of RFLP markers to an aluminum tolerance gene in wheat. Crop Sci. 1996;36(4):905-909.

37. Šarová J., Hanzalová A., Bartoš P. Incidence of wheat leaf spot pathogens in the Czech Republic. Cereal Res. Commun. 2003;31:145-151.

38. Singh P.K., Crossa J., Duveiller E., Singh R.P., Djurle A. Association mapping for resistance to tan spot induced by Pyrenophora triticirepentis race 1 in CIMMYTs historical bread wheat set. Euphytica. 2016;207(3):515-525. DOI 10.1007/s10681-015-1528-7.

39. Singh P.K., Mergoum M., Ali S., Adhikari T.B., Elias E.M. Genetics of wheat – Pyrenophora tritici-repentis interactions. Euphytica. 2010; 171:1-13. DOI 10.1007/s10681-009-0074-6.

40. Strelkov S.E., Lamari L. Host-parasite interactions in tan spot [Pyrenophora tritici-repentis] of wheat. Can. J. Plant Pathol. 2003;25:339- 349. DOI 10.1080/07060660309507089.

41. Tuori R.P., Wolpert T.J., Ciuffetti L.M. Purifcation and immunological characterization of toxic components from cultures of Pyrenophora tritici-repentis. Mol. Plant Microbe Interact. 1995;8:41-48.

42. Virdi S.K., Liu Z., Overlander M.E., Zhang Z., Xu S.S., Friesen T.L., Faris J.D. New insights into the roles of host gene-necrotrophic effector interactions in governing susceptibility of durum wheat to tan spot and Septoria nodorum Blotch. G3 (Bethesda). 2016;6(12):4139- 4150. DOI 10.1534/G3.116.036525.

43. Xu S.S., Friesen T.L., Mujeeb-Kazi A. Seedling resistance to tan spot and Stagonospora nodorum blotch in synthetic hexaploid wheats. Crop Sci. 2004;44:2238-2245.

44. Zhanarbekova A.B., Koishibayev M., Maraite H., Duveiller E., Mercado D.M., Sliamova N.D. The distribution of tan spot on wheat and race structure of Drechslera tritici-repentis in Kazakhstan and neighboring countries of CIS. Proc. Int. Sci. Conf. “Modern Problems of Plant Protection and Quarantine”. Almaty, 2005;371-376.

45. Zhang Z., Friesen T.L., Simons K.J., Xu S.S., Faris J.D. Development, identifcation, and validation of markers for marker assisted selection against the Stagonospora nodorum toxin sensitivity genes Tsn1 and Snn2 in wheat. Mol. Breed. 2009;23:35-49. DOI 10.1007/s11032-008-9211-5.