Induction of genes involved in anaplerotic pathways in male sterile A. thaliana.

LOBATO, M. E. G.; RIUS, S.; EDUARDO ZABALETA; ARAYA, A.; DIEGO FABIAN GOMEZ CASATI; BUSI, M. V.

Rosario

Congreso; XLII Reunión SAIB; 2006

Mitochondrial retrograde signaling is a pathway of communication from mitochondria to nucleus under normal and abnormal conditions. It involves multiple factors that sense and transmit mitochondrial signals to make changes in nuclear gene expression. These changes lead to a reconfiguration of the metabolism to accommodate cells to defects in mitochondria. To study the effect of a mitochondrial dysfunction induced by the expression of the unedited form of the subunit 9 of ATP synthase gene (u-ATP9) in Arabidopsis, we constructed transgenic plants expressing u-ATP9 under the control of two different floral promoters: Apetala3 and A9. Both plants expressing u-ATP9 exhibited a male sterile phenotype. Using microarrays, we analyzed the transcriptome changes in Arabidopsis AP3- and A9- u-ATP9 vs. wt plants. We found altered levels of several genes codifying for enzymes involved in glycolysis and Krebs cycle, such as two up-regulated malate dehydrogenases (At5g43330 and At1g04410), and down-regulation of a pyruvate decarboxylase (At5g54960). In agreement with the microarray data, we confirmed these results by RT-PCR and also correlate with changes in their enzymatic activity. This differential activity seems to enhance the production of energy under reduced pO2 as a hallmark of the hypoxic response.