INBA   12521
INSTITUTO DE INVESTIGACIONES EN BIOCIENCIAS AGRICOLAS Y AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Stink bugs (Nezara viridula) induce soybean MAPKs activation and expression of genes related with cell wall proteins in developing seeds modulating chemical defenses
Autor/es:
GIACOMETTI ROMINA; ILINA NATALIA; ZAVALA JORGE
Lugar:
Bogota
Reunión:
Congreso; III Congress of the Latin American Association of Chemical Ecology ~ALAEQ 2014; 2014
Institución organizadora:
ALAEQ
Resumen:
Stink bugs (Nezara viridula) are a key pest in soybean (Glycine max), which attack decreases yield crop. Plant response begins with the recognition of cell injury and oral secretions, triggering mitogen activated protein kinases (MAPK) pathway and inducing defenses against herbivores. Stink bugs preferentially feed on young developing seeds and inject toxic saliva that causes further tissue damage. Soybean MAPK?s role in mediating responses to insects attack remains largely unexplored. In this work we examined in developing seeds under attack of stink bugs the transcription of genes involved in cell wall modification, as well as early and late MAPKs involvement in defense modulation. We found that MPK3, MPK4 and MPK6 as well as a MPKK are differentially transcribed in time after insect perception. We analyzed the phosphorylation status and identified soybean MPK6 as an herbivore and wound-induced kinase, while MPK3 and MPK4 were found to be activated after SA and JA treatments. Although two critical genes involved in flavonoid synthesis, Phe-ammonia lyase (PAL2) and chalcone synthase (CHS7) were up-regulated under all treatments, only stink bug attack induced isoflavone synthase (IFS), an enzyme responsible for the synthesis of daidzein and genistein, which are the main chemical defenses against these insects. We also analyzed the cell wall transcriptional response and found that 72h after stink bugs attack increased the expression of expansine (EXP), xyloglucan endo-transferase (EXT), pectate lyase (PL) y polygalacturonase (PG). Our results suggest that stink bug attack not only increases the expression of cell wall genes causing a re-arrangement of the wall, but also triggers JA and SA-mediated defenses through a tightly regulated induction of MAPKs transcription and phosphorylation of particular MAPKs in a time-dependent fashion.