TPS-b family genes involved in signature aroma terpenes emission in ripe kiwifruit

Aroma is a critical factor influencing consumer acceptability of ripe fruit. When fruit are eaten, the aroma travels retronasally from the mouth into the olfactory receptors located in the nose after exhaling. In kiwifruit (Actinidia spp.), terpene volatiles such as α-terpinolene and 1,8-cineole have been shown to contribute to the characteristic aroma of ripe fruit. Notably, 1,8-cineole contributes a key floral/eucalyptus note to the aroma of ripe A. chinensis ‘Hort16A’ kiwifruit, based on sensory descriptive and discriminant analysis. Emission of α-terpinolene and 1,8-cineole in kiwifruit is induced by ethylene, and production peaks when fruit are at eating ripeness. Two monoterpene synthase TPS-b family genes have been isolated from the fruit of A. arguta and A. chinensis that produce α-terpinolene and 1,8-cineole, respectively. Here we discuss terpene volatiles with respect to fruit aroma and consumer sensory evaluation, analyze the gene structure and conserved motifs of TPS-b genes in published kiwifruit genomes and then construct a transcriptional regulatory network based on Actinidia TPS-b. These data provide further insights into the potential molecular mechanisms underlying signature monoterpene synthesis to improve flavor in kiwifruit.</p

Additional file 5 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 5. Multiple-sequence alignments of the B3 domain from LAV, RAV and ARF families of citrus. Red circles indicate identical amino acid residues. Color-coded GUIDANCE2 scores are presented for the citrus B3 domain sequences. Confidently aligned residues are colored in shades of magenta, whereas uncertain residues are colored in shades of blue. GUIDANCE2 scores which represent the degree of confidently aligned residues (1 corresponds to 100% certainty) are plotted below the alignment

Additional file 2 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 2 Ka/Ks calculation of the duplicated B3 gene pairs in sweet orange (Citrus sinensis) and pummelo (C. grandis)

Additional file 9 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 9. List of qRT-PCR primers used in this study

Additional file 4 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 4. Three-dimensional models of the B3 domain from citrus. The Ribbon diagram of the CsLAV1 B3 domain was built using the SWISS-MODEL server. The B3 domain consists of seven β-strands (β1-β7) that form an open β-barrel. Two α-helices (α1 and α2) project above and below the β-barrel

Additional file 7 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 7 Phylogenetic tree of the B3 proteins from citrus and Arabidopsis based on the neighbor-joining method using MEGA7 software. The reliability of the predicted tree was tested by bootstrapping with 1000 replicates. The percentage of neighbor-joining bootstrap replications (> 40%) is shown above each node

Additional file 3 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 3 One-to-one orthologous relationships between sweet orange/pummelo and Arabidopsis as well as those between sweet orange/pummelo and rice

Additional file 6 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 6. Multiple-sequence alignments of the B3 domain from the REM family of citrus. Red circles indicate conserved amino acid residues. Color-coded GUIDANCE2 scores are presented for the citrus B3 domain sequences. Confidently aligned residues are colored in shades of magenta, whereas uncertain residues are colored in shades of blue. GUIDANCE2 scores which represent the degree of confidently aligned residues (1 corresponds to 100% certainty) are plotted below the alignment

Additional file 8 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 8 Lists of B3 genes identified in Arabidopsis and rice

Additional file 1 of Genome-wide analysis of the citrus B3 superfamily and their association with somatic embryogenesis

Additional file 1 B3 genes identified in the genomes of sweet orange (Citrus sinensis) and pummelo (C. grandis)