Role of mirna7695 in controlling osnramp6 (naturial resistance associated macrophage protein 6) expression and defense responses in rice plants

• Autores: Cristina Peris Peris
• Directores de la Tesis: Blanca San Segundo de los Mozos (dir. tes.), Sonia del Campo (codir. tes.), Soledad Martos Arias (tut. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2016
• Idioma: español
• Tribunal Calificador de la Tesis: Charlotte Poschenrieder Wiens (presid.), Concha Domingo Carrasco (secret.), Ane Sesma (voc.)
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • MIRNA are a key regulators of wide range of rice plant process, from developmental to nutrient homeostasis and/or biotic stresses. That regulation is carry out by posttranscriptional regulation of its targets. This thesis is addressed the identification and functional characterization of miRNA7695/OsNramp6 during the rice defense response to M. oryzae, as well as their involvement in metal homeostasis. These studies are important to understand how the plant nutritional status could affect the pathogen infection progress or vice versa. A better understanding of the link between nutrition and biotic stress are important to develop strategies to improve plant stress tolerant, due the agronomic worldwide importance of rice.

    The work of this thesis is divided in two chapter. The first chapter focuses on identification of a novel miRNA, osa-miRNA7698, in the defense response to Magnaporthe oryzae. The overexpression of miR7698 down-regulates the short isoform of OsNramp6 gene, giving a resistance against M. oryzae. Moreover, rice plants that accumulates miR7698 also regulates genes involved in iron homeostasis.

    The second chapter is focused on functional characterization of OsNramp6 gene in metal homeostasis and in defense response to M. oryzae. In the studies here presented, we demonstrated how both long/short isoform of OsNRAMP6 are a membrane proteins capable of iron and manganese transport. The Osnramp6 knockout mutant confers resistance to M. oryzae and produce a biomass reduction when the plants were grown under sufficient metal supply, thus, supporting a role of OsNramp6 in plant growth.