INVESTIGADORES
MERINI Luciano Jose
congresos y reuniones científicas
Título:
Reactive oxygen species (ROS) and anthraquinones production in chitosan-elicitated Rubia tinctorum cell suspension cultures
Autor/es:
PERASSOLO, M; BUSTO, VD; QUVEDO, CV; CARDILLO, AB; MARTINEZ, CA; CUADRADO, V; MERINI, LJ; GIULIETTI, AM; RODRIGUEZ TALOU, J
Lugar:
Dalian - China
Reunión:
Simposio; IBS2008; 2008
Resumen:
Anthraquinones (AQs) are secondarymetabolites derived fromisochorismic
acid, _-ketoglutaric acid and isopentenyl diphosphate
(Han et al., 2001). Their production in Rubia tinctorum can be
induced by elicitors (Vasconsuelo et al., 2003). The response to
elicitation triggers the production of reactive oxygen species (ROS)
and cell death. AQs synthesis in R. tinctorum cell suspension cultures
elicitated by chitosan involves stimulation of PLC and PI3K,
changes in intracellular Ca2+ concentration and MAPK activation
(Vasconsuelo and Bolan, 2007). In defense responses, the pentose
phosphate pathway (PPP) is also stimulated. This route produces
NADPH, an antioxidant protection against ROS. The proline cycle
induces PPP by the generation of NADP+, cofactor of glucose-6-
phosphate dehydrogenase (G6PD), the first and limiting enzyme in
PPP. The aim of this work was to analyze the relationship between
elicitation, oxidative burst and cell death. R. tinctorum suspension
cultures were treated with chitosan (200 mg/L), chitosan plus
sodium nitroprussiate (SNP), chitosan plus lanthanum chloride
and chitosan plus diphenylene iodonium (DPI). Cell viability, G6PD
activity, AQs, proline, and extracellular H2O2 content were determined
after chitosan elicitation. AQs increased after 24 and 48 h
of chitosan elicitation. Cell death increased after 6 and 24 h, which
correlated with enhanced H2O2 production. The addition of DPI
resulted in decreased chitosan-induced cell death and H2O2 production.
Similar levels of AQs accumulationwere found in chitosan
and chitosan-DPI treatments. Cultures treated with chitosan and
lanthanum chloride showed lower levels of AQs and cell death
than chitosan alone. SNP prevented chitosan effects on cell cultures,
since a decrease in both cell death and H2O2 levels were observed.
It can be assumed that higher cell viability caused by SNP addition
is a consequence of its effect on H2O2 production. Proline levels
decreased after treatment with chitosan, as well as G6PD activity,
showing that in this case, PPP may not be induced by elicitation.
References
Han, Y., Van der Heijden, R., Verpoorte, R., 2001. Biosynthesis of anthraquinones in
cell cultures of the Rubiaceae. Plant Cell Tissue Organ Cult. 67, 201220.
Vasconsuelo, A.A., Bolan, R., 2007. Molecular aspects of the early stages of elicitation
of secondary metabolites in plants. Plant Sci. 172, 861875.
Vasconsuelo, A.A., Giuletti, A.M., Picotto, G., Rodríguez Talou, G., Boland, J.R., 2003.
Involvement of the PLC/PKC pathway in Chitosan-induced anthraquinone production
by Rubia tinctorum L. cell cultures. Plant Sci. 165, 429436.
doi:10.1016/j.jbiotec.2008.07.804