Organelle DNA contents and starch accumulation in potato tubers

Interaction of starch and non-starch polysaccharides in raw potato flour and their effects on thickening stability

The present study sought to explore the potential of raw potato flour prepared from two common potato varieties (Atlantic and Favorita) as a thickener and the underlying mechanisms of its thickening stability based on the chemical component content, chemical group, starch, pectin, cell wall integrity, and the cell wall strength of raw potato flour. The raw potato flour prepared from Favorita potato (FRPF) showed great potential as a thickener with a valley viscosity/peak viscosity of 97.24 %. Additionally, the viscosity of FRPF after heat treatment, acid treatment and shear treatment was maintained at 70.73 %, 65.99 % and 78.89 % of the original viscosity, respectively, which is better than that of ARPF (44.98 %, 47.03 % and 61.57 %, respectively). The results also revealed that high pectin content, cell wall integrity and strength contributed significantly to the thickening stability of potato meal, which was achieved by limiting the swelling and disintegration of starch. Finally, the correctness of the principle was verified using the raw potato flour prepared from four types of potatoes (Heijingang, Innovator, Qingshu No. 9, and Guinongshu No. 1). Overall, the development of thickener from raw potato flour has broadened the variety of clean label additives in the food industry.

Transcriptomic and proteomic data provide new insights into cold-treated potato tubers with T- and D-type cytoplasm

Tuber-omics in potato with the T- and D-types of cytoplasm showed different sets of differentially expressed genes and proteins in response to cold storage. For the first time, we report differences in gene and protein expression in potato (Solanum tuberosum L.) tubers possessing the T- or D-type cytoplasm. Two F1 diploid reciprocal populations, referred to as T and D, were used. The pooling strategy was applied for detection of differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) in tubers consisting of extreme chip colour after cold storage. RNA and protein bulks were constructed from contrasting phenotypes. We recognized 48 and 15 DEGs for the T and D progenies, respectively. DEPs were identified in the amyloplast and mitochondrial fractions. In the T-type cytoplasm, only 2 amyloplast-associated and 5 mitochondria-associated DEPs were detected. Of 37 mitochondria-associated DEPs in the D-type cytoplasm, there were 36 downregulated DEPs in the dark chip colour bulks. These findings suggest that T- and D-type of cytoplasm might influence sugar accumulation in cold-stored potato tubers in different ways. We showed that the mt/nucDNA ratio was higher in D-possessing tubers after cold storage than in T progeny. For the D-type cytoplasm, the pt/nucDNA ratio was higher for tubers characterized by dark chip colour than for those with light chip colour. Our findings suggest that T- and D-type cytoplasm might influence sugar accumulation in cold-stored potato tubers in different ways.