Alteration of pectin metabolism in blood orange fruit (<i>Citrus sinensis</i> cv. Tarocco) in response to vesicle collapse

Abstract Segment drying is a severe physiological disorder of citrus fruit, and vesicles become granulated or collapsed. Aside from the hypothesis that alteration cell wall metabolism main factor granulation, little known about vesicle collapse. This study aimed to elucidate changes in pectin during collapse blood orange. Vesicle was characterized by decreased nutrients increased chelate- sodium carbonate-soluble calcium content. The nanostructure chelate-soluble became complex developed multi-branching upon activity methylesterase increased, while polygalacturonase pectate lyase Genome-wide transcriptional analysis revealed an increasing pattern genes encoding other enzymes involved synthesis demethylesterification Drying were abscisic acid content relevant gene expression. In conclusion, we discovered underlying collapse, mainly promoting demethylesterification, remodeling structures, further inhibiting degradation, which hypothesized be for first disclose potential intrinsic mechanism orange fruit.