An oxidoreductase from ‘Alphonso’ mango catalyzing biosynthesis of furaneol and reduction of reactive carbonyls

Abstract

Two furanones, furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) and mesifuran (2,5-dimethyl-4-methoxy-3(2H)-furanone), are important constituents of flavor of the Alphonso cultivar of mango (Mangifera indica). To get insights into the biosynthesis of these furanones, we isolated an enone oxidoreductase gene from the Alphonso mango. It has high sequence similarity to an alkenal/one oxidoreductase from cucumber (79% identity) and enone oxidoreductases from tomato (73% identity) and strawberry (72% identity). The complete open reading frame was expressed in E. coli and the (his)6-tagged recombinant protein was purified by affinity chromatography. The purified protein assayed with NADH as a reducing agent converted D-fructose-1,6-diphosphate into furaneol, the immediate precursor of mesifuran. The enzyme was also able to convert two highly reactive carbonyls, 3-buten-2-one and 1-penten-3-one, produced by lipid peroxidation in plants, into their saturated derivatives. Expression profiling in various ripening stages of Alphonso fruits depicted an expression maxima at 10 days after harvest stage, shortly before the appearance of the maximum amount of furanones (completely ripe stage, 15 days after harvest). Although no furanones were detected at the 0 day after harvest stage, significant expression of this gene was detected in the fruits at this stage. Overall, the results suggest that this oxidoreductase plays important roles in Alphonso mango fruits.

Chemometrics-Based Aroma Discrimination of 14 Egyptian Mango Fruits of Different Cultivars and Origins, and Their Response to Probiotics Analyzed via SPME Coupled to GC–MS

“…These cvs were reported to have Indian origins showing the same pattern of Indian originated fruits . Another volatile of interest is β-terpinene (P25), found mainly in AI and HSS and AI at 39.2 and 19.4%, respectively, and at a trace level in “founs” cv regardless of its geographic origin, that is, FD and FI, Table , and in agreement with the report by Kulkarni et al…”

Transcriptional transitions in Alphonso mango (Mangifera indica L.) during fruit development and ripening explain its distinct aroma and shelf life characteristics

“…Furaneol and mesifuran are the two furanones from Alphonso mango and their synthesis by enone oxidoreductase ( EO ) and O-methyltransferase ( OMTS ), respectively have been described earlier 10 , 11 . Multiple contigs coding for quinone oxidoreductase and O-methyltransferases were detected in the present analysis.…”

“…On the other hand in the current study various contigs encoding novel EH (three contigs), EH2 (four contigs) and peroxygenase (three contigs) were detected. Similarly, multiple transcripts encoding enone oxidoreductase and O-methyltransferase having role in furanone biosynthesis 10 , 11 were also identified and expression profiles of many of them were shown to be ripening specific (Supplementary Figure SF7 ). Abundance and ripening related expression of large number of these unique flavor related genes in Alphonso mango (Supplementary Figure SF7 ) signifies their role in synthesis of diverse aroma volatiles and their unique blend giving sweet and fruity flavor in Alphonso as shown by our previous studies 34 , 35 .…”

An ETHYLENE RESPONSE FACTOR-MYB Transcription Complex Regulates Furaneol Biosynthesis by Activating QUINONE OXIDOREDUCTASE Expression in Strawberry

“…The biosynthetic pathway of HDMF in other plants is similar to that in strawberry. Genes with homology to FaQR have been identified in tomato (SlEO) and mango (Mangifera indica; MiEO; Klein et al, 2007;Kulkarni et al, 2013).…”