Journal of General Plant Pathology

, Volume 85, Issue 6, pp 458–462 | Cite as

Exploring the origin of crop pathogens: host-specific toxin-producing pathogens as a case study

  • Takashi TsugeEmail author
Presidential Address


In the agroecosystem, new diseases often occur within several years after the introduction of a new crop species or cultivar. These diseases, referred to as “man-made diseases”, appear only on newly introduced crops that are genetically susceptible to the pathogens. Because these new diseases appear very soon after the introduction of a new crop, the pathogen most likely did not arise by mutation after cultivation began, but was already present in the population as a potential pathogen. How do pathogens emerge in the field? How and where do potential pathogens live and maintain their pathogenicity until they meet a host crop? Information on the origin of crop pathogens is still very limited.

Since 1981, I have worked on Alternaria alternatapathogens, which produce host-specific toxins (HSTs). HSTs produced by fungal pathogens are generally low-molecular weight secondary metabolites with a diverse range of structures that function as effectors controlling pathogenicity or...



I express my deepest gratitude to all my colleagues and students for their enthusiastic collaboration and cooperation with this research. Most of this work was supported by Grants-in-Aid for research projects from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.

Compliance with ethical standards

Conflict of interest

The author declares that he has no conflicts of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by the author.


  1. Akagi Y, Akamatsu H, Otani H, Kodama M (2009) Horizontal chromosome transfer, a mechanism for the evolution and differentiation of a plant-pathogenic fungus. Eukaryot Cell 8:1732–1738CrossRefGoogle Scholar
  2. Akamatsu H, Taga M, Kodama M, Johnson R, Otani H, Kohmoto K (1999) Molecular karyotypes for Alternaria plant pathogens known to produce host-specific toxins. Curr Genet 35:647–656CrossRefGoogle Scholar
  3. Brandwagt BF, Mesbah LA, Takken FLW, Laurent PL, Kneppers TJA, Hille J, Nijkamp HJJ (2000) A longevity assurance gene homolog of tomato mediates resistance to Alternaria alternata f. sp. lycopersici toxins and fumonisin B1. Proc Natl Acad Sci USA 97:4961–4966CrossRefGoogle Scholar
  4. Covert SF (1998) Supernumerary chromosomes in filamentous fungi. Curr Genet 33:311–319CrossRefGoogle Scholar
  5. Dewey RE, Siedow JN, Timothy DH, Levings CS III (1988) A 13-kilodalton maize mitochondrial protein in E. coli confers sensitivity to Bipolaris maydis toxin. Science 239:293–295CrossRefGoogle Scholar
  6. Han Y, Liu X, Benny U, Kistler HC, VanEtten HD (2001) Genes determining pathogenicity to pea are clustered on a supernumerary chromosome in the fungal plant pathogen Nectria haematococca. Plant J 25:305–314CrossRefGoogle Scholar
  7. Hatta R, Ito K, Hosaki Y, Tanaka T, Tanaka A, Yamamoto M, Akimitsu K, Tsuge T (2002) A conditionally dispensable chromosome controls host-specific pathogenicity in the fungal plant pathogen Alternaria alternata. Genetics 161:59–70PubMedPubMedCentralGoogle Scholar
  8. Ishii K (2002) Remembrance on the Japanese pear “Nijisseiki” and breeder Mr. Kakunosuke Matsudo (in Japanese). Shokubutsu-boeki [Plant Prot] 56(1):41–43Google Scholar
  9. Johal GS, Briggs SP (1992) Reductase activity encoded by the HM1 disease resistance gene in maize. Science 258:985–987CrossRefGoogle Scholar
  10. Johnson LJ, Johnson RD, Akamatsu H, Salamiah A, Otani H, Kohmoto K, Kodama M (2001) Spontaneous loss of a conditionally dispensable chromosome from the Alternaria alternata apple pathotype leads to loss of toxin production and pathogenicity. Curr Genet 40:65–72CrossRefGoogle Scholar
  11. Li Y, Aldwinckle HS, Sutton T, Tsuge T, Kang G, Cong P-H, Cheng Z-M (2013) Interactions of apple and the Alternaria alternata apple pathotype. Crit Rev Plant Sci 32:141–150CrossRefGoogle Scholar
  12. Lorang JM, Carkaci-Salli N, Wolpert TJ (2004) Identification and characterization of victorin sensitivity in Arabidopsis thaliana. Mol Plant-Microbe Interact 17:577–582CrossRefGoogle Scholar
  13. Lorang JM, Sweat TA, Wolpert TJ (2007) Plant disease susceptibility conferred by a “resistance” gene. Proc Natl Acad Sci USA 104:14861–14866CrossRefGoogle Scholar
  14. Lorang JM, Hagerty CH, Lee R, McClean PE, Wolpert TJ (2018) Genetic analysis of victorin sensitivity and identification of a causal nucleotide-binding site leucine-rich repeat gene in Phaseolus vulgaris. Mol Plant Microbe Interact 31:1069–1074CrossRefGoogle Scholar
  15. Meehan F, Murphy HC (1947) Differential phytotoxicity of metabolic by-products of Helminthosporium victoriae. Science 106:270–271CrossRefGoogle Scholar
  16. Miao VP, Covert SF, VanEtten HD (1991) A fungal gene for antibiotic resistance on a dispensable (“B”) chromosome. Science 254:1773–1776CrossRefGoogle Scholar
  17. Nakashima T, Ueno T, Fukami H, Taga T, Masuda H, Osaki K, Otani H, Kohmoto K, Nishimura S (1985) Isolation and structures of AK-toxin I and II, host-specific phytotoxic metabolites produced by Alternaria alternata Japanese pear pathotype. Agric Biol Chem 49:807–815Google Scholar
  18. Nishikawa J, Nakashima C (2019) Morphological and molecular characterization of the strawberry black leaf spot pathogen referred to as the strawberry pathotype of Alternaria alternata. Mycoscience 60:1–9CrossRefGoogle Scholar
  19. Nishimura S, Kohmoto K (1983) Host-specific toxins and chemical structures from Alternaria species. Annu Rev Phytopathol 21:87–116CrossRefGoogle Scholar
  20. Ohtani K, Yamamoto H, Akimitsu K (2002) Sensitivity to Alternaria alternata toxin in citrus because of altered mitochondrial RNA processing. Proc Natl Acad Sci USA 99:2439–2444CrossRefGoogle Scholar
  21. Sekiguchi A (1976) Studies on the Alternaria leaf spot disease of apple caused by Alternaria mali Roberts (in Japanese with English summary). Bull Nagano Hort Exp Stn 12:1–64Google Scholar
  22. Sekiguchi A, Ueno T, Fukami H, Hayashi Y, Nakashima T, Nishimura S (1974) Pathogenicity of Alternaria mali Rob. and toxicity of AM toxin to various plants (abstract in Japanese). Jpn J Phytopathol 40:149CrossRefGoogle Scholar
  23. Tanaka S (1933) Studies on black spot disease of the Japanese pear (Pyrus serotina Rehd.). Mem Coll Agric Kyoto Univ 28:1–31Google Scholar
  24. Thomma BPHJ (2003) Alternaria spp.: from general saprophyte to specific parasite. Mol Plant Pathol 4:225–236CrossRefGoogle Scholar
  25. Tsuge T, Harimoto Y, Akimitsu K, Ohtani K, Kodama M, Akagi Y, Egusa M, Yamamoto M, Otani H (2013) Host-selective toxins produced by the plant pathogenic fungus Alternaria alternata. FEMS Microbiol Rev 37:44–66CrossRefGoogle Scholar
  26. Tsuge T, Harimoto Y, Hanada K, Akagi Y, Kodama M, Akimitsu K, Yamamoto M (2016) Evolution of pathogenicity controlled by small, dispensable chromosomes in Alternaria alternata pathogens. Physiol Mol Plant Pathol 95:27–31CrossRefGoogle Scholar
  27. Wolpert TJ, Dunkle LD, Ciuffetti LM (2002) Host-selective toxins and avirulence determinants: what’s in a name? Annu Rev Phytopathol 40:251–285CrossRefGoogle Scholar
  28. Woudenberg JHC, Seidl MF, Groenewald JZ, de Vries M, Stielow JB, Thomma BPHJ, Crous PW (2015) Alternaria section Alternaria: Species, formae speciales or pathotypes? Study Mycol 82:1–21CrossRefGoogle Scholar

Copyright information

© The Phytopathological Society of Japan and Springer Japan KK, part of Springer Nature 2019

Authors and Affiliations

  1. 1.College of Bioscience and TechnologyChubu UniversityKasugaiJapan

Personalised recommendations