“…Once a certain level is reached, AC no longer increases in GBSSI-enhanced lines possibly because of the limited non-reducing ends in amylose and the substrate competition between amylose and amylopectin (Tsai et al, 1970; Smith et al, 2002; Sestili et al, 2012). The promotion of AC in SSIIa nulls varies widely in different species; for instance, the elimination of SSIIa unlikely change AC in rice alk (Umemoto et al, 2004, 2008), moderately increases AC (40–50%) in maize sugary2 ( su2 ) and wheat sgp-1 (Yamamori et al, 2000; Tziotis et al, 2004; Zhang et al, 2004), and yields about 50% AC in barley sex6 (Morell et al, 2003). Compared with the effectiveness of SBE inactivation for high-amylose cereal crops, which have remarkable increase in AC (Li et al, 2008; Carciofi et al, 2012; Zhu et al, 2012; Regina et al, 2015), the enhanced AC in SSIIa nulls is moderate (Yamamori et al, 2000; Tziotis et al, 2004; Zhang et al, 2004).…”