Amylose-extender

Variation in amylose concentration is also observed between butt, center and tip zones within individual ae ears, with the highest percentage in kernels taken from the butt of the ear and the lowest percentage in kernels from the tip zone.317 In addition, when the endosperm tissue is divided into tip, middle and crown portions, the middle portion is highest in amylose percentage within each ear zone.317 

Starch granules from ae kernels have a much higher BEPT than normal or the other mutants (Table 3.4). Also, based on 14 genotypes studied, the B-type x-ray diffraction pattern appears to be unique to ae and ae -containing genotypes (Table 3.4). 

Mutator induced mutations of branching enzyme I have also been developed.341 In these mutants neither leaf nor endosperm starch differed in structure from the normal starches. 

Sugary allele Ears sampled, no. Kernel weight, mg Glucoseb Fructoseb Sucroseb WSPb Starchb 

Brown et al.238 reported that starch granules from 18- and 24-day-old su2 kernels are weakly birefringent and have an A-type x-ray pattern (Table 3.4), in contrast to the B-type pattern reported for starch granules from mature su2 kernels.360,387 The BEPT of su2 granules is lower than that of normal granules (Table 3.4).359,388 Based 

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Amylose extender mutants have been found in rice.272 The alteration of the starch structure is very similar to that reported for maize endosperm ae mutants. The defect is in the BE3 isozyme, BE3 of rice being more similar in amino acid sequence to maize BE11 than to BEl.36,272 Thus, rice BE3 may catalyze the transfer of small chains, rather than long chains. 

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