Relationships among starch biosynthesizing protein content, fine structure and functionality in rice

Abstract

The underlying mechanisms behind the genetics, structure and functionality relations in starches from various origins have not been fully understood. For better control of the genotypic background, rice starches from four chalky mutants and their parent were employed to investigate the above relations, and some interesting relations were revealed. GBSSI and SSIIIa were shown to affect the height of amylose in the debranched starch fraction (h_AM) which reflects true amylose content (TAC), and then h_AM was correlated with the AAC, RS, HD, COH, To, ΔHg, ΔHr, and R%. GBSSI also affected the average chain length (X)¯ of amylopectin, which was associated with the AAC, TAC, RS, HPV, HD, COH, ΔHg, ΔHr, and R%. The SSI, SSIIa and SSIIIa affected the amylose size (R_h,AM), which was correlated with the TAC, AAC, RS, HD, COH, To and Tp. Furthermore, both SSIIa and PUL affected the X_AP2, and X_AP2 was correlated with the To.

Keywords: Amylopectin; Biosynthesis; Resistant starch; Rice; Starch; Structure.