RAPISARDA Viviana Andrea
congresos y reuniones científicas
RNA-SEQ TRANSCRIPTIONAL PROFILING OF Herbaspirillum seropedicae IN RESPONSE TO SUFFICIENT AND HIGH PHOSPHATE CONCENTRATION
GRILLO-PUERTAS, M.; PANKIEVICZ, V.C.; TADRA-SFEIR, M.; PEDRAZA, R.O.; RAPISARDA, V.A.; SOUZA, E.M.
Congreso; Segunda Reunión Conjunta de Sociedades de BioCiencias; 2017
Herbaspirillum seropedicae is a diazotrophic and endophytic bacterium associated with important agricultural crops, promoting plant growth and increasing productivity. Its agricultural use requires studies on its physiological response to prevailing levels of nutrients such as phosphate (Pi). It has been previously reported in different bacteria that environmental Pi modulates the levels of intracellular polyphosphate (polyP), a molecule that plays important roles in microbial metabolism. The aim of this work was to evaluate the intracellular polyP levels and the differentially expressed genes in H. seropedicae grown in sufficient or high Pi conditions. H. seropedicae SmR1 was grown in NFbHN-malate medium modified with 5 or 50 mM Pi; culture absorbance at 600nm and polyP levels were measured at different times during 24 h. Results showed that cultures grown in high Pi medium reached higher cell densities than cultures grown in sufficient Pi media and maintained high polyP levels in stationary phase. To analyze if these differences in polyP levels could generate changes in gene expression, mRNA from cell grown in different media was purified and used for RNA-seq profiling. Comparison of RNA profile between sufficient and high Pi conditions revealed that 620 genes were differentially expressed, being 53 and 43% repressed and induced by high Pi, respectively. Most of the induced genes in the high Pi condition were involved in energy production process, two component regulatory systems, amino acid transport and metabolism, chemotaxis and inorganic ion transport and metabolism. The ability to respond to environmental signals which modulates polyP production could be critical in diverse aspects of H. seropedicae.