For example, we identified a heat shock protein gene (Private_087) and a stress-inducible gene (Private_101) induced during ripening, consistent with the ability of Corvina berries to undergo dehydration for up to 100 days [ 26, 27].
A gene encoding pectinesterase (TC14614) showed a decrease in expression during fruit development and ripening, consistent with the modification of pectin which occurs during ripening.
Amino-acid levels decreased, coupled with the elevation of transcripts involved with amino acid and organic acid catabolism during ripening stage, consistent with the mobilization of amino acids to support respiration.
The correlated expression of anthocyanin biosynthetic genes with color change during ripening is consistent with coordinated regulation by a MYB transcription factor, as reported in many other fruits [ 36].
However, unlike Arabidopsis, the expression of tomato EBF1 and EBF2 was not constitutive, with a transient decrease in expression at the onset of ripening (mature green), and consistent with Arabidopsis both showed an increase of expression with ethylene and a decrease with auxin (Yang et al. 2010).
Contigs related to lactose and galactose transport and utilization were expressed by molds only at the very beginning of cheese ripening, which is consistent with the negligible concentration of lactose in the rind after six days of ripening [ 5].
Our results confirm the findings of Romar et al. [ 49] showing that genes involved in the carotenoid biosynthetic pathway are not coregulated during chili fruit ripening, which is consistent with the hypothesis regarding differences in the expression of these genes.
26 UniGenes involved in sucrose metabolism were identified (Table 2), and the expression of five UniGenes encoding sucrose phosphate synthase (SPS) (GenBank accession no. JR053941 to JR053943) increased rapidly (Table 2, Figure 6B and Additional File 10) during fruit ripening, which was consistent with q-PCR results.
Conversely, several components of the photosynthetic machinery were identified as decreasing greater than 1.5-fold along ripening initiation, which is consistent with a reduction in photosynthesis at this period of berry development.
The presence of an apoplasmic step during radial transfer of sucrose in ripening internodes of sorghum is consistent with expectations for plant organs after the transition from growth to accumulation of large amounts of osmoticum [ 18].
Amongst all detected amino acids, the levels of alanine, glutamate and aspartate declined least in dates with late ripening profile (Additional file 6), consistent with previous work looking at ripening in tomato [ 39].
