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Time-Resolved Transcriptomics Provides Insights into Cultivar-Dependent Sucrose Loss During Ambient Storage of Sweet Corn

Year: 2026

Type: article

Abstract: Postharvest sucrose depletion severely limits the organoleptic quality and commercial value of sweet corn during ambient storage. To characterize the temporal transcriptional responses associated with cultivar-dependent sugar loss, ears of two supersweet corn hybrids, ‘Shenketian 811’ (SKT) and ‘Overland’ (AFL), were stored under monitored ambient conditions (24–26 °C) for 7 days. Kernel sugars, total soluble solids, whole-ear respiration rates, and transcriptomic profiles were assessed at five time points. Sucrose concentration declined from 77.9 to 30.9 μg mg−1 fresh weight in SKT and from 80.3 to 20.3 μg mg−1 fresh weight in AFL. Weighted gene co-expression network analysis (WGCNA), followed by within-cultivar module–trait analysis, identified one module positively and one negatively associated with sucrose concentration in both cultivars. Subsequent gene-level correlation analysis of the 1071 genes in these modules identified 571 non-redundant sucrose-associated genes, which were enriched in carbon metabolism, glycolysis/gluconeogenesis, the citrate cycle, and starch and sucrose metabolism. Pairwise differential-expression analysis further identified 194 genes showing recurrent storage-responsive or cultivar-dependent expression, of which five genes involved in sucrose cleavage or sucrose–starch interconversion were prioritized. Notably, the cell-wall invertase gene ZmINVCW1 exhibited a sustained AFL-biased expression pattern, which was validated by RT-qPCR, while total cell wall invertase activity was also significantly higher in AFL at multiple sampling points. This time-resolved analysis characterizes recurrent transcriptional responses associated with cultivar-dependent sucrose loss and provides a focused framework for further functional studies of postharvest sucrose retention.

Source: Plants

DOI: 10.3390/plants15213413