Infection induced oxidative cross-linking of hydroxyproline-rich glycoproteins (HRGPs) is associated with restriction of Colletotrichum sublineolum in sorghum

Puttalingaiah Basavaraju*, Shekar Shailasree, Nandini P. Shetty, Ramachandra K. Kini, Hans J.L. Jørgensen, Eigil de Neergaard, Hunthrike S. Shetty

*Corresponding author for this work

    Research output: Contribution to journalJournal articleResearchpeer-review

    11 Citations (Scopus)

    Abstract

    Hydroxyproline-rich glycoproteins (HRGPs) accumulation and oxidative cross-linking is one of the earliest defense responses in plants against pathogen infection. In the present study HRGP accumulation in three sorghum genotypes i.e. SC146 (resistant), SC326 (intermediately resistant) and BTx623 (susceptible) as a response to Colletotrichum sublineolum isolate CP2126 infection is elucidated. HRGPs were monitored by hydroxyproline (Hyp) estimation. In genotypes SC146 and SC326 there was a significantly higher amounts of Hyp at 2 days after inoculation (dai) compared to genotype BTx623, indicating an infection induced accumulation of HRGPs. Western blot analysis of acid-ethanol extracted proteins with polyclonal antibody raised against pearl millet purified HRGPs identified four bands with molecular masses of ∼65, 45, 17 and 14 kDa as HRGPs. Insolubilization of the 45 kDa protein in genotypes SC146 and SC326 upon infection with C. sublineolum indicates a role of this protein in cell wall cross-linking, coinciding with heavier accumulation of hydrogen peroxide. In addition, tissue print analysis using polyclonal antibody of pearl millet HRGPs recognized these cross-linked proteins to be HRGPs. These findings indicated that HRGPs in sorghum is a component of defense reaction against C. sublineolum infection.

    Original languageEnglish
    JournalJournal of Plant Interactions
    Volume4
    Issue number3
    Pages (from-to)179-186
    Number of pages8
    ISSN1742-9145
    DOIs
    Publication statusPublished - 2009

    Keywords

    • Disease resistance
    • Hydrogen peroxide
    • Hydroxyproline
    • Hydroxyproline-rich glycoproteins
    • Sorghum anthracnose

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