The degree of starch phosphorylation as influenced by phosphate deprivation of potato (Solanum tuberosum L.) plants

Abstract

SummaryThe levels of starch phosphorylation in potato tubers were investigated in relation to fertilization with phosphorus (P) of field-grown and greenhouse-grown plants. The field-grown plants received 0, 15 or 30 kg P ha -1. Starch from plants grown without P-fertilizer contained 15.6 nmol P (mg starch) -l whereas starch from plants grown with 30 kg P ha -l contained 20.6 nmol P (mg starch) -1. The greenhouse-grown plants were cultured in inert media and received nutrient solutions containing 0, 3, 12 or 24 mg P l -l, respectively. Plants grown with no Pfertilizer produced tuber starch with phosphorylation levels reduced to approximately 30% of the level found in plants grown with an ample supply of P. Thus, the level of starch phosphorylation can be modified by limiting the P-supply through the root system. Application of foliar P-fertilizer to the greenhouse-grown plants had no significant effect on the phosphorylation of the tuber starch.

Health‐beneficial properties of potato and compounds of interest

“…Most phosphorylation occurs at the C6 position (70–80%), while only 20–30% occurs at the C3 position . On average, one out of every 200–300 glucose units is reported to be phosphorylated . Noda et al studied the phosphorus content of 69 potato cultivars and reported a range between 434 and 1087 µg g −1 .…”

“…39 On average, one out of every 200-300 glucose units is reported to be phosphorylated. 40 Noda et al 41 studied the phosphorus content of 69 potato cultivars and reported a range between 434 and 1087 μg g −1 . The lowest content was observed in Setoyutaka and the highest in Kachikei No.…”

Increased expression of the MYB‐related transcription factor, PHR1, leads to enhanced phosphate uptake in Arabidopsis thaliana

“…Each pot contained five plants and 1 L of aerated nutrient solution. The nutrient solution used contained the following macro-and micronutrients: 1.8 mm KNO3, 0.2 mm MgSO4 · 7H2O, 0.7 mm NH4SO4, 1.25 mm Mg(NO3), 8.4 mm NaCl, 3.7 mm MnSO4, 1.6 mm ZnSO4, 0.76 mm CuSO4, 2.7 mm H3BO3, 0.18 mm Na2MoO4, 1.9 mm Ca(NO3)2 and 8 mm Fe-ethylenediaminetetraacetic acid (EDTA); the pH of the solution was adjusted to 5.5 (after Jacobsen et al 1998;Müller et al 2004). The plants were grown for 2 weeks with half strength of the nutrient solution supplied with 20 mm Pi (high-P plants) or 1 mm (low-P plants).…”

Physico‐chemical properties of starches isolated from potato cultivars grown in soils with different phosphorus availability

“…The degree of phosphorylation has a profound effect on the physical and chemical properties of the starch. Because the degree of phosphorylation influences the qualitative properties of starch there is interest in the effect of environmental parameters; specifically, to what extent starch phosphorylation can be manipulated by controlling phosphate supply to the plants …”

“…Because the degree of phosphorylation influences the qualitative properties of starch there is interest in the effect of environmental parameters; specifically, to what extent starch phosphorylation can be manipulated by controlling phosphate supply to the plants. 12 Noda et al 13 studied the starch P content in potato cultivars and its effect on starch properties and their results indicated that enhancing the starch phosphate resulted in significant increases in the swelling power, peak viscosity, and breakdown and significant but small increases in the onset and peak temperatures of gelatinization. Other starch quality parameters, such as the amylose content, granule median size, and the gelatinization enthalpy, did not significantly change due to the degree of phosphate substitution of starch.…”