Biosynthesis and Regulation of Wheat Amylose and Amylopectin from Proteomic and Phosphoproteomic Characterization of Granule-binding Proteins

Abstract

Waxy starch has an important influence on the qualities of breads. Generally, grain weight and yield in waxy wheat (Triticum aestivum L.) are significantly lower than in bread wheat. In this study, we performed the first proteomic and phosphoproteomic analyses of starch granule-binding proteins by comparing the waxy wheat cultivar Shannong 119 and the bread wheat cultivar Nongda 5181. These results indicate that reduced amylose content does not affect amylopectin synthesis, but it causes significant reduction of total starch biosynthesis, grain size, weight and grain yield. Two-dimensional differential in-gel electrophoresis identified 40 differentially expressed protein (DEP) spots in waxy and non-waxy wheats, which belonged mainly to starch synthase (SS) I, SS IIa and granule-bound SS I. Most DEPs involved in amylopectin synthesis showed a similar expression pattern during grain development, suggesting relatively independent amylose and amylopectin synthesis pathways. Phosphoproteome analysis of starch granule-binding proteins, using TiO2 microcolumns and LC-MS/MS, showed that the total number of phosphoproteins and their phosphorylation levels in ND5181 were significantly higher than in SN119, but proteins controlling amylopectin synthesis had similar phosphorylation levels. Our results revealed the lack of amylose did not affect the expression and phosphorylation of the starch granule-binding proteins involved in amylopectin biosynthesis.

Preliminary study of ratio of amylose and amylopectin as indicators of glycemic index and in vitro enzymatic hydrolysis of rice and wheat starches

“…In both wheat and rice, amylopectin and amylose content are exactly the same. The amylopectin content in rice is 80%-85% and that in wheat is 75% according to Guan-Xing Chen et al 9 The value obtained in this wheat and rice sample is slightly higher than the reference range. The normal range of amylose content in rice is from 3% -20% according to Abas A et al 10 And according to Guan-Chen X et al, wheat usually consists of 25% amylose.9 According to Behall KM et al, compared to amylose, amylopectin led to a greater increase in blood sugar and insulin levels.…”

Identification and molecular characterization of mutant line deficiency in three waxy proteins of common wheat (Triticum aestivum L.)

“…Furthermore, the total starch content decreased in the Wx-null line (48.13%) compared to wild-type Gao 8901 (53.61%). Although GBSS I enzyme deficiency does not affect amylopectin synthesis, it causes a significant reduction in total starch biosynthesis [78]. Unlike corn starch granules characterized by more uniform size, wheat starch granules exhibit two main populations of large A-type and smaller B-type.…”

Acceptability and proximate composition of two Filipino delicacies, puto seko and panganan from arrowroot (Maranta arundinaceae, L.)

“…The higher the amount of amylopectin present the lower the hardness of the baked product and the higher the amylose content, the higher its hardness value (Horstmann et al, 2016). Studies revealed that arrowroot starch has low amylose and high amylopectin content (Erdman, 1986;Pérez and Lares, 2005) as compared to wheat flour with a high amount of amylose (Van Hung et al, 2006;Chen, et al, 2016).…”

“…But Pérez and Lares (2005), reported that it has high amylopectin content of 84.79%. In contrast, the amylose and amylopectin content of wheat flour ranges from 25-28% amylose and 72-75% amylopectin (Van Hung et al, 2006;Chen, et al, 2016).…”