Comparative flower metabolomics analysis in polygamodioecious Garcinia indica choisy indicates flower gender type specific metabolite accumulation

Abstract

The knowledge of flower metabolic changes during flower development is limited in dioecious species. To better understand the abundance and variation of metabolites between these flower types is of utmost interest. Our aim was to investigate metabolite diversity and accumulation in three different flower types of Garcinia indica. Here we used High performance liquid chromatography-collision induced dissociation-quadrupole time of flight-mass spectroscopy (HPLC-CID-QTOF-MS) to identify and quantify metabolites. Further by using statistical analysis tools namely Mass Hunter, XCMS and MetaboAnalyst we generated comparative metabolomics data. We annotated 910 metabolites which were further classified into six major categories. The statistical analysis revealed that 11 flavonoids were differentially accumulated in male, female and bisexual flowers, and certain metabolites helped to distinguish among three flower types. The kaempferol and quercetin derivatives with sugar moieties showed high occurrence in female depicting major difference in principal component 1. Moreover, the occurrence of sugars and amino acids was found higher in bisexual and female flowers. Additionally, pathway analysis dissected 17 impactful pathways, prominently amino acid and TCA showing higher impact on flower development whereas 12 joint-pathways showed correlation between MADS- box gene and metabolites. Interestingly, selenoprotein, one of the rarely found genes in plants was also detected which can be helpful to elucidate the role of selenoprotein in plant kingdom. Altogether, this work provides the first untargeted metabolite analysis in G. indica flowers which can serve as a foundation to understand the mechanism of metabolites in flower development.