Starch phosphorylation plays an important role in starch biosynthesis

Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways

“…Reversible glucan phosphorylation at the granule surface is essential for complete starch breakdown (Silver et al , 2014). The semi-crystalline matrix of the starch granule surface is disrupted by phosphorylation mediated by glucan, water dikinase (GWD) and phosphoglucan, water dikinase (Baunsgaard et al , 2005; Kötting et al , 2005; Xu et al , 2016). In potato leaves, the phosphorylation level of the starch granule surface is increased during starch breakdown (Ritte et al , 2004).…”

Heterologous expression of two Arabidopsis starch dikinases in potato

“…An early study has shown that SUSY4 is a major determinant of tuber sink strength and the suppression of this gene leads to an inhibition of starch accumulation in potato tubers . In previous research, the inhibition of GWD1 expression led to the downregulation of a series of key genes including SUSY4 , thus we hypothesized that starch phosphorylation affects starch metabolism partly by regulating the flux into the amyloplast . Further experiments are needed to examine if the expression of AtGWD2 directly or indirectly triggers such regulation in potato tuber.…”

“…In addition, KDG3 transformants showed a consistent increase in the expression of GBSSI , AGPase , UGPase , and SP compared to the control. It has been reported that the expression level of GWD1 in potato tubers affects that of key genes involved in the starch metabolic pathway . It is, therefore, likely that AtGWD3 may play a similar role in the regulation of starch metabolism and this hypothesis remains to be elucidated.…”

“…Tubers from five plants from the same clone were pooled together to minimize individual variation, and starch isolation was performed according to the procedure and analyzed as described in Ref. . These included starch chain length distribution, particle size distribution, granule morphology, amylose content, phosphate content, and starch gelatinization properties.…”

Genetic and molecular approaches to valorise protein and fibre in potato

“…To inspect for starch in PCW, samples were visualized microscopically by using scanning electron microscopy (SEM) (Phenom™, FEI, Eindhoven, The Netherlands) as previously described (Xu et al 2017).…”