Physical Changes in Satsuma Mandarin Leaf after Infection of Elsinoë fawcettii Causing Citrus Scab Disease

  • Paudyal, Dilli Prasad (Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration) ;
  • Hyun, Jae-Wook (Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration)
  • Received : 2015.05.21
  • Accepted : 2015.08.13
  • Published : 2015.12.01


Citrus scab disease is one of the destructive diseases that reduce the value of fruit for the fresh market. We analyzed the process of symptom development after infection with scab pathogen $Elsino{\ddot{e}}$ fawcettii in the susceptible satsuma mandarin leaves to observe the structural modification against pathogen. The cuticle and epidermal cells along with 3-5 layers of mesophyll tissue were degraded 1-2 days post inoculation. Surrounding peripheral cells of degraded tissues grew rapidly and then enveloped the necrotic area along with the growing conidia. Cross sections through the lesion revealed hyphal colonization in epidermis and mesophyll tissues. In response to the pathogen colonization, host cell walls were lignified, inner cells were rapidly compartmentalized and a semi-circular boundary was formed that separated the infected region from the non-infected region, and finally prevented the intercellular pathogen spread.


Grant : Cooperative Research Program for Agriculture Science & Technology Development

Supported by : Rural Development Administration


  1. Achor, D. S., Albrigo, L. G. and McCoy, C. W. 1991. Developmental anatomy of lesions on 'Sunburst mandarin leaves initiated by citrus rust mite feeding. J. Am. Soc. Hort. Sci. 116:663-668.
  2. Agrios, G. N. 2005. Plant Pathology. ELSEVIER academic press, New York.
  3. Bellincampi, D., Cervone, F. and Lionetti, V. 2014. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions. Front. Plant Sci. 5:228.
  4. Bhuiyan, N. H., Selvaraj, G., Wei, Y. and King, J. 2009. Role of lignification in plant defense. Plant Signal. Behav. 4:158-159.
  5. Chung, K. R. 2011. Elsinoe fawcettii and Elsinoe australis: the fungal pathogen causing citrus scab. Mol. Plant Pathol. 12:123-135.
  6. Dodds, P. N. and Rathjen, J. P. 2010. Plant immunity: towards an integraded view of plant-pathogen interactions. Nat. Rev. Genet. 11:529-548.
  7. Gabel, A. W. and Tiffany, L. H. 1987. Host-parasite relations and development of Elsinoe panici. Mycologia 79:737-744.
  8. Hyun, J. W., Paudyal, D. P., Hwang, R. Y. and Kim, K. S. 2014. Improved method to increase the conidia production from citrus scab pathogen (Elsinoe spp.). Res. Plant Dis. 21:231-234.
  9. Hyun, J. W., Timmer, L. W., Lee, S. C., Yun, S. H., Ko, S. W. and Kim, K. S. 2001. Pathological characterization and molecular analysis of Elsinoe isolates causing scab disease of citrus in Jeju Island in Korea. Plant Dis. 85:1013-1017.
  10. Hyun, J. W., Yi, S. H., MacKenzie, S. J., Timmer, L. W., Kim, K. S., Kang, S. K., Kwon, H. M. and Lim, H. C. 2009. Pathotypes and genetic relationship of worldwide collections of Elsinoe spp. causing scab disease of citrus. Phytopathology 99:721-728.
  11. Kim, K. W., Hyun, J. W. and Park, E. W. 2004. Cytology of cork layer formation of citrus and limited growth of Elsinoe fawcettii in scab lesions. Eur. J. Plant Pathol. 110:129-138.
  12. Kolattukudy, P. E. 1984. Biochemistry and function of cutin and suberin. Can. J. Bot. 62:2918-2933.
  13. Kubicek, C. P., Starr, T. L. and Glass, N. L. 2014. Plant cell wall-degrading enzymes and their secretion in plant-pathogenic fungi. Annu. Rev. Phytopathol. 52:427-451.
  14. Lodha, T. D., Hembram, P., Tep, N. and Basak, J. 2013. Proteomics: a successful approach to understand the molecular mechanism of plant-pathogen interaction. Am. J. Plant Sci. 4: 1212-1226.
  15. Simard, M., Rioux, D. and Laflamme, G. 2001. Formation of lingo-suberized tissues in jack pine resistant to the European race of Gremmeniella abietina. Phytopathology 91:1128-1140.
  16. Timmer, L. W. 2000. Scab Diseases. In: Compendium of citrus diseases. ed. by G.S. Timmer, L.W., Graham, J.H., pp. 31-32. The American Phytophathological Society, APS Press.
  17. Vance, C. P., Kirk, T. K. and Sherwood, R. T. 1980. Lignification as a mechanism of disease resistance. Annu. Rev. Phytopathol. 18:259-288.
  18. Vargas, W. A., Martin, J. M. S., Rech, G. E., Rivera, L. P., Benito, E. P., Diaz-Minguez, J. M., Thon, M. R. and Sukno, S. A. 2012. Plant defense mechanisms are activated during biotrophic and necrotrophic development of Colletotricum graminicola in Maize. Plant Physiol. 158:1342-1358.

Cited by

  1. Electron microscopic observations of sooty moulds on crape myrtle leaves 2017,
  2. Infection and symptom development by citrus scab pathogen Elsinoë fawcettii on leaves of satsuma mandarin vol.148, pp.4, 2017,