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

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, Delta Hg, Delta Hr, and R%. GBSSI also affected the average chain length ((X) over bar) of amylopectin, which was associated with the AAC, TAC, RS, HPV, HD, COH, Delta Hg, Delta Hr, and R%. The SSI, SSIIa and SSIIIa affected the amylose size (R-h,R- 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.