The Rust Fungi

Abstract

The rust fungi are a monophyletic group of approximately 7000 species in the basidiomycota and are highly specialized obligate parasites of plants. The life cycle of rusts can be complex. Some rusts have up to five spore stages that alternate between haploid and dikaryotic nuclear conditions and that can occur on two taxonomically unrelated host plants. The rusts have evolved specialized structures that allow them to penetrate and obtain nutrients from living host cells. Biologic forms of a single rust species may differ in ability to attack different genera of host plants. Furthermore, within a single rust species they can be highly variable in ability to attack different genotypes of one host species. At the species level, genes that condition avirulence/virulence in rusts interact in a specific relationship with rust‐resistance genes in plants. Many of the most important plant diseases in the world are caused by rust fungi.

Key concepts:

  • The rust fungi are a monophyletic group of approximately 7000 species within the basidiomycota, the group of fungi that includes mushrooms and shelf fungi.

  • Rust fungi have complex life cycles with up to five spore stages that alternate between haploid and dikaryotic nuclear condition on two unrelated host plants.

  • The rust fungi are obligate parasites of plants and have evolved specialized structures to infect and obtain nutrients from plants.

  • Rusts have a highly specific host range. Genes in rust that express avirulence or virulence interact with rust‐resistance genes in host plants to condition a compatible or incompatible interaction. Some rust species are highly variable for biologic forms that vary in their ability to attack host genotypes with different rust‐resistance genes.

  • Many of the most important plant diseases worldwide are caused by rust fungi.

Keywords: basidiomycota; uredinales; plant disease; fungi

Figure 1.

Life cycle of a macrocyclic‐heteroecious rust. (a) mature, diploid teliospore, (b) basidia with basidiospores, (c) pycnial (sprermogonial) stage, (d) aecial stage, (e) uredinial stage and (f) telial stage. From Alexopoulos et al., drawn by Carol Gubbins Hahn.

Figure 2.

Diagrammatic representation of infection structures of a cereal rust fungus. (a) Uredinial infection structures at 60 h. U, urediniospore; GT, germ tube; A, appresoria; GC, stomatal guard cell; PP, penetration peg; SV, substomatal vesicle; IH, infection hyphae; PH, primary haustoria; ICH, intercellular hyphae; H, additional haustoria. Drawn by James Chong. Reproduced from Harder . (b) Cross section of invaded host cell at the site of penetration to show three‐dimensional representation of a mature haustoria and association with host cell organelles. E, EH, extrahaustorial matrix; EM, extrahaustorial membrane; ER, endoplasmic reticulum; FN, fungal nucleus; G, golgi body; HB, haustorial body; HMC, haustorial mother cell; HN, haustorial neck; M, mitochondria; N, host nucleus; P, plasmalemma; R, ring neck; T, tubule complex; V, vesicle; W, host cell wall. Drawn by James Chong. Reproduced from Harder and Chong . (c) Urediniospore formation on a cereal leaf. U, urediniospores; SC, sporogenous cell; SB, spore bud; UI, urediniospore initial; PD, pedicel; N, nucleus; V, vacuole. Drawn by James Chong. Reproduced from Harder . Used with permission from Elsevier.

Figure 3.

Uredinial infection of Hemileia vastatrix (coffee rust). Photo courtesy of Howard Schwartz.

Figure 4.

(a) Aecial infection of Cronartium ribicola (white pine blister rust) on pine tree. USDA Forest Service, Ogden UT. (b) Uredinia of Cronartium ribicola on Ribes sp. Robert Anderson, USDA Forest Service.

Figure 5.

(a) Stem rust caused by Puccinia graminis f.sp. tritici on wheat – photo by Yue Jin –USDA‐ARS. (b) Leaf rust caused by P. triticina on wheat – photo by James Kolmer. (c) Stripe rust caused by P. striiformis f. sp. tritici on wheat – photo by James Kolmer – USDA‐ARS.

close

References

Agrios GN (2004) Plant Pathology, 5th edn. San Diego: Academic Press.

Aime MC (2006) Toward resolving family level relationships in rust fungi (Urediniales). Mycoscience 47: 112–122.

Alexopoulus CJ (1962) Introductory Mycology. New York: Wiley.

Alexopoulus CJ, Mims CW and Blackwell M (1996) Introductory Mycology, 4th edn. New York: Wiley.

Anikster Y (1984) The formae specialis. In: Bushnell WR and Roelfs AP (eds) The Cereal Rusts, vol. I. Orlando: Academic Press.

Anikster Y, Bushnell WR, Eilam T, Manisterski J and Roelfs AP (1997) Puccinia recondita causing leaf rust on cultivated wheats, wild wheats, and rye. Canadian Journal of Botany 75: 2082–2095.

Arthur JC (1929) The Plant Rusts (Urediniales). New York: Wiley.

Arthur JC (1934) Manual of the Rusts in United States and Canada. Lafayette, IN: Purdue Research Foundation.

Coutinho TA, Rijkenberg FHJ and Van Asch MAJ (1995) Teliospores of Hemilia vastatrix. Mycological Research 99: 932–934.

Cummins GB and Caldwell RM (1956) The validity of binomials in the leaf rust complex of cereals and grasses. Phytopathology 46: 81–82.

Cummins GB and Hiratsuka N (2003) Illustrated Genera of Rust Fungi, 3rd edn. St. Paul, MN: American Phytopathological Society.

Dodds P, Lawrence GJ, Catanzariti AM, Ayliffe MA and Ellis JG (2004) The Melampsora lini Avr567 avirulence genes are expressed in haustoria and their products are recognized inside plant cells. The Plant Cell 16: 755–768.

Ellis JG, Dodds PN and Lawrence GJ (2007) Flax rust resistance gene specificity is based on direct resistance‐avirulence protein interactions. Annual Review of Phytopathology 45: 289–306.

Eriksson J (1899) Nouvelles etudes sur la rouille brune des Cereales. Annals of Science Natural Botany 1(Series 8): 241–288.

Flor HH (1971) Current status of the gene‐for‐gene concept. Annual Review of Phytopathology 9: 275–296.

Hansen M and Lewis KJ (1997) Compendium of Conifer Diseases. St. Paul, MN: American Phytopathological Society.

Harder DE (1984) Developmental ultrastructure of hyphae and spores. In: Bushnell WR and Roelfs AP (eds) The Cereal Rusts, vol. I. Orlando: Academic Press.

Harder DE and Chong J (1984) Structure and physiology of Haustoria. In: Bushnell WR and Roelfs AP (eds) The Cereal Rusts, vol. I. Orlando: Academic Press.

Huang L, Brooks SA, Li W et al. (2003) Map‐based cloning of leaf rust resistance gene Lr21 from the large and polyploid genome of wheat. Genetics 164: 655–664.

Maloy OC (1997) White pine blister rust control in North America: a case history. Annual Review of Phytopathology 35: 87–109.

Mendgen K and Hahn M (2002) Plant infection and the establishment of fungal biotrophy. Trends in Plant Science 7: 352–356.

Milus EA and Seyran E (2006) Aggressiveness of Puccinia striiformis f. sp. tritici isolates in the south‐central United States. Plant Disease 90: 847–852.

Pirone PP (1978) Diseases & Pests of Ornamental Plants, 5th edn. New York: Wiley.

Roelfs AP, Singh RP and Saari EE (1992) Rust Diseases of Wheat: Concepts and Methods of Disease Management. Mexico DF: Centro Internacional Mejormiento de Trigo y Maize (CIMMYT).

Savile DBO (1953) Short‐season adaptation in the rust fungi. Mycologia 45: 75–87.

Savile DBO (1976) Evolution of the rust fungi (Urediniales) as reflected by their ecological problems. Evolutionary Biology 9: 137–207.

Schieber E and Zentmeyer GA (1984) Coffee rust in the western hemisphere. Plant Disease 68: 89–93.

Stakman EC and Piemeisel FJ (1917) A new strain of Puccinia graminis. Phytopathology 7: 73.

Staples RC and Macko V (1984) Germination of urediospores and differentiation of infection structures. In: Bushnell WR and Roelfs AP (eds) The Cereal Rusts, vol. I. Orlando: Academic Press.

Swann EC, Frieders EM and McLaughlin DJ (2001) Urediniomycetes. In: McLaughlin DJ and Lemke P (eds) The Mycota VII. B. Systematics and Evolution. Berlin: Springer.

Tainter FH and Baker FA (1996) Principes of Forest Pathology. New York: Wiley.

Walker JC (1969) Plant Pathology, 3rd edn. New York: McGraw‐Hill.

Webster J (1980) Introduction to Fungi. Oxford: Cambridge University Press.

Williams PG (1984) Obligate parasitism and axenic culture. In: Bushnell WR and Roelfs AP (eds) The Cereal Rusts, vol. I. Orlando: Academic Press.

Wynn WK and Staples RC (1981) Tropisms of fungi in host recognition. In: Staples RC and Toenniessen GA (eds) Plant Disease Control: Resistance and Susceptibility. New York: Wiley.

Further Reading

Bolton MD, Kolmer JA and Garvin DF (2008) Wheat leaf rust caused by Puccinia triticina. Molecular Plant Pathology 9: 563–575.

Lawrence GJ, Dodds PN and Ellis JG (2007) Rust of flax and linseed caused by Melampsora lini. Molecular Plant Pathology 8: 349–364.

Leonard KJ and Szabo LS (2005) Stem rust of small grains and grasses caused by Puccinia graminis. Molecular Plant Pathology 6: 99–111.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Kolmer, James A, Ordonez, Maria E, and Groth, James V(Sep 2009) The Rust Fungi. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0021264]