ARABIDOPSIS MITOCHONDRIAL ALKALINE/NEUTRAL INVERTASE C IS IMPORTANT FOR GERMINATION AND FLOWERING

MARTIN ML; MARTINEZ NOEL G; EDUARDO JULIAN ZABALETA; SALERNO, GL

San Luis

Congreso; XLVII Reunión Anual de SAIB; 2011

Invertases (Invs) catalyze the irreversible hydrolysis of sucrose intohexoses and play a key role when a demand of carbon and energyoccurs. It has become evident that sucrose and its hydrolysisproducts are important metabolic signals that modulate geneexpression and regulate plant development. Alkaline-Neutralinvertases (A/N-Invs) have maximum activity at characteristic pHsbetween 6.5–8.0. Their physiological functions are not clear yet.A/N-Invs are mainly located in the cytosol but recently differentsubcellular locations were unraveled, although their roles are stillunknown. In this work, we focused on the mitochondrialArabidopsis At-A/N-InvC. Transcripts of At-A/N-InvC weredetected in every tissue analyzed. Its biochemical identity wascharacterized by expression in E. coli cells. To explore itsphysiological function, invc knockout mutant plants were analyzedand compared with recently characterized inva mutant plants. Lackof At-A/N-InvC expression in homozygous mutant plants wasverified by RT-PCR assays. A detailed phenotypic analysis showedthat mutant plants present a developmental alteration relative to Col-0 plants, including delayed germination and flowering time,emphasizing the role of mitochondrial sucrose hydrolysis indevelopment processes.