Independent Researcher CONICET / Adjunct Professor UNC
Physiological role of T2 ribonucleases in plants subjected to different stress scenarios
Our laboratory is involved in two research projects related with the biological role of T2 ribonucleases (RNases) in Nicotiana alata: A) Plants exposed to phosphate (Pi) starvation seem to use a combined strategy of Pi remobilization from internal and external RNA sources. Thus far, the only ribonucleases reported to be induced in Nicotiana alata undergoing Pi deprivation are extracellular S-like RNase NE and NnSR1, a class III non S-RNase derived from the self-incompatibility system which is localized in endoplasmic reticulum compartments. In order to find out the exact physiological role of RNases under Pi stress scenarios, we are following a strategy of post-transcriptional silencing of RNase NE and NnSR1. We are also interested in investigate whether the induction of these two RNases is simultaneous or sequential as well as the study of the Pi threshold triggering such induction. B) We are interested in elucidate the temporal alterarations of the cytoskeleton and the endomembrane system of rejected pollen tubes in the S-RNase based self-incompatibility system. Our aim is to detemine the causes of pollen growth arrest an the precise role of S-RNases in such process.
- Eliana Escobar – PhD student
- Carolina Caspani – Undergraduate Student
- Juan Roldan, Hernan Rojas and Ariel Goldraij (2014). In vitro inhibition of incompatible pollen tubes in Nicotiana alata involves the uncoupling of the F-actin cytoskeleton and the endomembrane trafficking system. Protoplasm. 10.1007/s00709-014-0658-4.
- Hernán Rojas, Juan Roldan and Ariel Goldraij (2013). NnSR1, a class III non-S-RNase constitutively expressed in styles, is induced in roots and stems under phosphate deficiency in Nicotiana alata. Annals of Botany 112: 1351-1360.
- Juan Roldan, Hernan Rojas and Ariel Goldraij (2012) Disorganization of F-actin cytoskeleton precedes vacuolar disruption in pollen tubes during the in vivo self-incompatibility response in Nicotiana alata Annals of Botany 110: 787-795.
- Juan Roldan, Rodrigo Quiroga and Ariel Goldraij (2010) Molecular and genetic characterization of novel S-RNases from a natural population of Nicotiana alata. Plant Cell Rep 29: 735-746.
- Goldraij A, Kondo K, Lee CB, Hanckock CN, Vazquez-Santana S, Sivaguru M, Vázquez-Santana S, Kim Sunran, Phillips TE, Cruz-García F and McClure B (2006) Compartmentalization of S-RNase and HT-B degradation in self-incompatible Nicotiana. Nature 439: 805-810.
- Doctor in Chemical Sciences (1995), Universidad Nacional de Córdoba, Argentina
- Agronomic Engineer (1985), Universidad Nacional de Córdoba, Argentina
- Researcher (2005-2015) Faculty of Science Chemical-CIQUIBIC-CONICET, Universidad Nacional de Córdoba, Argentina
- Postdoctoral position (2003-2005) Dr Bruce McClure lab, Department of Biochemistry, College of Agriculture, Foods and Natural Resources, University of Missouri-Columbia, USA.
- Postdoctoral position (1996-1999 and 2002-2003) Dr Joseph Polacco lab, Department of Biochemistry, College of Agriculture, Foods and Natural Resources, University of Missouri-Columbia, USA.
- Graduate student (1990-1995) Juan Curtino Faculty of Science Chemical Lab-CIQUIBIC, Universidad Nacional de Córdoba, Argentina
- Present position: Adjunct Professor, Biololgical Chemistry, Chemistry Faculty, Universidad Nacional de Córdoba.
Background on Science outreach and extension
- Secretary of Extension (2014-2017), School of Chemistry, Universidad Nacional de Córdoba, Argentina.
Directed Ph.D. Theses
- Juan Alfredo Roldán (2013) “Cellular and Molecular Basis of Self-incompatibility in Nicotiana: Organization and dinamycs of F-actin cytoskeleton and endomembrane system of pollen tubes during the rejection process”. School of Chemistry, Universidad Nacional de Córdoba, Argentina.
- Javier Hernán Rojas (2014) “Root expression and endoplasmic reticulum localization of NnSR1, a T2 class III non-S-RNase induced under phosphate starvation in Nicotiana alata” Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.