Infection induced defence responses in sorghum, with special emphasis on accumulation of reactive oxygen species and cell wall modifications

Abstract

Hemibiotrophic plant pathogens pass both biotrophic and necrotrophic phases during their infection cycle. Colletotrichum spp. exhibits two types of hemibiotrophy, i.e. intracellular and subcuticular intramural. Colletotrichum sublineolum infecting sorghum exhibits a typical intracellular type of hemibiotrophy. During the biotrophic stage of C. sublineolum infection in sorghum, several cell wall-associated defence reactions are activated and efficiently participate in stopping pathogen development. Among these defence reactions, generation and accumulation of reactive oxygen species (ROS) and cell wall barrier formation are key factors in resistance. This review focuses on the infection processes of C. sublineolum in sorghum and the defence responses activated, with special emphasis on accumulation of ROS and hydroxy-rich glyco-proteins (HRGPs).

Keywords:

• Hemibiotrophy
• Colletotrichum sublineolum
• sorghum
• defence responses
• active oxygen species
• hydroxyproline-rich glycoproteins

Acknowledgements

The authors would like to thank Danish International Development Assistance (DANiDA), Denmark, for financial assistance. Authors had discussions with most of the cited authors of unpublished works and would wish to thank them and to apologise to any researchers whose relevent work was not cited or discussed in this review.