Changes in the Metabolite Profile During Micropropagation of Normal and Somaclonal Variants of Banana Musa AAA cv. ´Williams´

Abstract

BackgroundMicropropagation techniques allow the mass production of pathogen-free banana plants but can cause somaclonal variations (SV) such as dwarfism. Changes in the metabolite profile during micropropagation of true-to-type (normal) and dwarf banana plants have not been described. Normal and dwarf banana Musa AAA cv. “Williams” were micropropagated and the metabolite profile of vitroplants was assessed at the proliferation, rooting and greenhouse-acclimatization phases of tissue culture. Metabolites from 10 dwarf and 10 normal meristems from each micropropagation phase were extracted and detected by gas chromatography coupled to mass spectrometry (GC-MS). Principal component analysis (PCA) and test of statistical significance were applied to detect differentially expressed metabolites. ResultsThe PCA showed a clear grouping of the dwarf plants (DPs) separated from the normal plants (NPs) in the rooting and acclimatization phases. In the proliferation phase, L-sorbose was significantly more abundant in DPs when compared to NPs. In the rooting phase, the aerial parts of the DPs showed significantly higher levels of 2-Keto-d-gluconic and citric acids but lower levels of fructose when compared to NPs. The meristems of DPs from the acclimatization phase showed significantly higher levels of D-galactose, gulonic acid and D- galacturonic acid but lower levels of mannose and L-fucose when compared to the NPs. Some molecules, such as L-glutamin and uridin were only detected in NPs from this phase. ConclusionsResults suggest the presence of oxidative stress and changes in the constitution of the apoplast at the different stages potentially affecting cell shape and phenotypic traits in DPs.