Cerebroside Elicitors Found in Diverse Phytopathogens Activate Defense Responses in Rice Plants

Abstract

Cerebrosides A and C, compounds categorized as glycosphingolipids, were isolated in our previous study from the rice blast fungus (Magnaporthe grisea) as novel elicitors which induce the synthesis of rice phytoalexins. In this paper, these cerebroside elicitors showed phytoalexin-inducing activity when applied to plants by spray treatment and also induced the expression of pathogenesis-related (PR) proteins in rice leaves. This elicitor activity of the cerebrosides showed the structural specificity as that for the induction of phytoalexins. Ceramides prepared from the cerebrosides by removal of glucose also showed the elicitor activity even in lower level compared to the cerebrosides. In field experiments, the cerebroside elicitors effectively protected rice plants against the rice blast fungus, an economically devastating agent of disease of rice in Japan. The cerebrosides elicitors protected rice plants from other disease as well and were found to occur in a wide range of different phytopathogens, indicating that cerebrosides function as general elicitors in a wide variety of rice-pathogen interactions.

Cerebroside mediated elicitation of defense response in chilli (Capsicum annuumL.) againstColletotrichum capsiciinfection

“…Furthermore, they confirmed that cerebroside isolated from various species of F. oxysporum also induced resistance against various fusarium diseases. Presence of cerebrosides was reported in a wide variety of fungi, which included, Aspergillus niger (Wagner and Fiegert 1969), Schizophyllum commune (Kawai and Ikeda 1982) Lentinus cdodes (Kawai 1989), Saccharomyces cerevisiae (Dickson and Lester 2002), Magnaporthe grecia, and F. oxysporum (Umemura et al 2000 and. We isolated cerebroside from F. oxysporum f. sp.…”

“…Since cerebrosides contain one sugar unit, they are also called ceramide monohexosides (Barreto-Bergter et al 2004). Cerebrosides were earlier extracted and purified from various fungi (Wagner and Fiegert 1969;Umemura et al 2000;Takakuwa et al 2002). Elicitor activity of purified cerebrosides was demonstrated earlier and found to induce phytoalexin and pathogenesis related (PR) protein synthesis, hypersensitive responses (HR) and resistance to infection by compatible pathogens in rice (Koga et al 1998;Umemura et al 2000 and, pearl millet (Deepak et al 2003), and tomato (Umemura et al 2004).…”

Glucosylceramide Synthases, a Gene Family Responsible for the Biosynthesis of Glucosphingolipids in Animals, Plants, and Fungi

“…The structural features required to induce this effect have been identified in studies with different molecular species of GlcCer from the phytopathogen Magnaporthe grisea (21,22). The identification of downstream members of this signaling cascade is a prerequisite for understanding the molecular mechanism of this plant-pathogen interaction.…”

Induction of Chlorosis, ROS Generation and Cell Death by a Toxin Isolated fromPyricularia oryzae

“…Interestingly, ceramides prepared from the cerebrosides by removing glucose also had elicitor activity toward rice leaves. 27) Like Mag-toxin, coronatine has also been reported to be a phytotoxin that induced chlorosis via a lightdependent process. 28) Coronatine has been shown to induce a red chlorophyll catabolite reductase that catalyzed one step in the breakdown of the porphyrin component of chlorophyll.…”