Temporal patterns of gene expression associated with tuberous root formation and development in sweetpotato (Ipomoea batatas).

BACKGROUND: The tuberous root of sweetpotato is undisputedly an important organ from agronomic and biological perspectives. Little is known regarding the regulatory networks programming tuberous root formation and development. RESULTS: Here, as a first step toward understanding these networks, we analyzed and characterized the genome-wide transcriptional profiling and dynamics of sweetpotato root in seven distinct developmental stages using a customized microarray containing 39,724 genes. Analysis of these genes identified temporal programs of gene expression, including hundreds of transcription factor (TF) genes. We found that most genes active in roots were shared across all developmental stages, although significant quantitative changes in gene abundance were observed for 5,368 (including 435 TFs) genes. Clustering analysis of these differentially expressed genes pointed out six distinct expression patterns during root development. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that genes involved in different processes were enriched at specific stages of root development. In contrast with the large number of shared expressed genes in root development, each stage or period of root development has only a small number of specific genes. In total, 712 (including 27 TFs) and 1,840 (including 115 TFs) genes were identified as root-stage and root-period specific, respectively at the level of microarray. Several of the specific TF genes are known regulators of root development, including DA1-related protein, SHORT-ROOT and BEL1-like. The remaining TFs with unknown roles would also play critical regulatory roles during sweetpotato tuberous root formation and development. CONCLUSIONS: The results generated in this study provided spatiotemporal patterns of root gene expression in support of future efforts for understanding the underlying molecular mechanism that control sweetpotato yield and quality.

Effect of domestic cooking methods on the anthocyanins and antioxidant activity of deeply purple-fleshed sweetpotato GZ9.

Purple-fleshed sweetpotatoes (PFSPs) are considered to be a healthy food and there are many methods to process in family. This study aimed to investigate the effects of various domestic cooking on the anthocyanin variation and antioxidant activity of a newly bred purple-fleshed cultivar Guangzishu 9 (GZ9) with anthocyanin content up to 1,500 mg/100g dry weight. As a result, total 15 individual anthocyanins were separated and identified by using UPLC-QTOF-MS. Top three anthocyanins were cyanidin 3-dicaffeoyl sophoroside-5-glucoside, cyanidin 3-caffeoyl- p-coumaryl sophoroside-5-glucoside and peonidin 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside, which accounting for 57.27% of the total anthocyanin content. Acylated anthocyanins were the major constituents in GZ9, and the type of anthocyanins was dominated by cyanidin. Boiling, steaming and mircrowaving had no significant effect on the total anthocyanin content. But baking, frying, air-frying and stir-frying reduced 11-45% of total anthocyanin content. Through ABTS+ radical scavenging capacity and reducing power, antioxidant variations were also observed during different family cooking, and the variation had a strong correlation with total anthocyanin content.