Polyploidy may cause the appearance of novel phenotypes which may have important significance for breeding purposes. The present work attempts to investigate the molecular mechanisms occurring after genome duplication and utilises the biosynthetic pathway of anthocyanins as a model. To this end, chemically induced autotetraploid Solanum commersonii plants, kindly provided by Prof D. Carputo (University of Naples "Federico II") were evaluated for the accumulation of anthocyanins in leaves. Preliminary investigations showed that polyploids had a higher accumulation of red pigments especially when grown in vitro in sucrose enriched medium with respect with the diploid line. In a following experiment detached leaves from four independent 4x lines and control diploid plants were grown in liquid MS medium supplemented with increased amount of sucrose ranging from 0 to 10% w/v The anthocyanin accumulation, observed in the abaxial page of the leaves, correlated with sucrose content in the medium in the tetraploids. On the contrary, the control genotype did not show any evident effect of the increased concentration of sucrose as the leaves showed few red pigments, if any. The expression of regulatory (i.e R2R3MYB) and structural (i.e DFR and ANS) genes of the anthocyanin pathway was assessed by qRT-PCR analysis at different days from the beginning of the treatment. The key genes of the anthocyanin pathway showed a dose dependent upregulation in the tetraploid lines only. Conversely, a significant modification of gene expression was not observed in the diploid line. In summary our preliminary analyses indicated that also in potato, as previously reported in other species (Solfanelli et al., 2006), sucrose may incite anthocyanin synthesis. Sugars not only fuel cellular carbon and energy metabolism but also play pivotal roles as signaling molecules (Rolland et al., 2006). We interpret our preliminary results to mean that polyploidization event has misregulated the sugar sensing mechanism present in diploid plants. Further analyses are ongoing to test this hypothesis.
PLOIDY DEPENDENT ANTHOCYANIN ACCUMULATION IN SOLANUM COMMERSONII PLANTS
DAMIANI F;PASSERI V;PAOLOCCI F
2012
Abstract
Polyploidy may cause the appearance of novel phenotypes which may have important significance for breeding purposes. The present work attempts to investigate the molecular mechanisms occurring after genome duplication and utilises the biosynthetic pathway of anthocyanins as a model. To this end, chemically induced autotetraploid Solanum commersonii plants, kindly provided by Prof D. Carputo (University of Naples "Federico II") were evaluated for the accumulation of anthocyanins in leaves. Preliminary investigations showed that polyploids had a higher accumulation of red pigments especially when grown in vitro in sucrose enriched medium with respect with the diploid line. In a following experiment detached leaves from four independent 4x lines and control diploid plants were grown in liquid MS medium supplemented with increased amount of sucrose ranging from 0 to 10% w/v The anthocyanin accumulation, observed in the abaxial page of the leaves, correlated with sucrose content in the medium in the tetraploids. On the contrary, the control genotype did not show any evident effect of the increased concentration of sucrose as the leaves showed few red pigments, if any. The expression of regulatory (i.e R2R3MYB) and structural (i.e DFR and ANS) genes of the anthocyanin pathway was assessed by qRT-PCR analysis at different days from the beginning of the treatment. The key genes of the anthocyanin pathway showed a dose dependent upregulation in the tetraploid lines only. Conversely, a significant modification of gene expression was not observed in the diploid line. In summary our preliminary analyses indicated that also in potato, as previously reported in other species (Solfanelli et al., 2006), sucrose may incite anthocyanin synthesis. Sugars not only fuel cellular carbon and energy metabolism but also play pivotal roles as signaling molecules (Rolland et al., 2006). We interpret our preliminary results to mean that polyploidization event has misregulated the sugar sensing mechanism present in diploid plants. Further analyses are ongoing to test this hypothesis.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
