Relationships between starch synthase I and branching enzyme isozymes determined using double mutant rice lines

BMC Plant Biology

Table 3 Composition of carbohydrate (weight%) in endosperm starch fractions separated by gel filtration chromatography

Lines		Fr. I (%)^a	Fr. II (%)	Fr. III (%)	TAC (%)^e	III/II
Wild type	Starch^b	21.3 ± 0.3^d	20.4 ± 0.0	58.5 ± 0.3	18.2	2.9 ± 0.0
(Nipponbare)	Amylopectin^c	3.0 ± 0.4	17.7 ± 0.9	54.4 ± 1.8	-	3.1 ± 0.1
Wild type	Starch	22.1 ± 0.8	20.6 ± 0.0	57.4 ± 0.9	19.0	2.8 ± 0.0
(Taichung 65)	Amylopectin	2.8 ± 0.1	19.4 ± 0.0	57.7 ± 0.1	-	3.0 ± 0.0
ss1	Starch	23.3 ± 0.4^,*	18.7 ± 0.4^*	58.0 ± 0.1	20.8^*	3.1 ± 0.1
(e7)	Amylopectin	2.5 ± 0.2^**	18.6 ± 0.5	58.2 ± 4.5	-	3.1 ± 0.2
be1	Starch	21.7 ± 1.2	19.5 ± 0.4	58.8 ± 1.5	18.1	3.0 ± 0.1
(EM557)	Amylopectin	3.6 ± 0.1^,*	19.0 ± 0.3	58.4 ± 1.2	-	3.1 ± 0.1
ss1/be1	Starch	21.4 ± 0.3	20.5 ± 0.8	58.1 ± 0.6	20.0	2.9 ± 0.1
(#4011)	Amylopectin	1.4 ± 0.1^***	20.2 ± 0.9	57.6 ± 1.1	-	2.9 ± 0.2
Wild type	Starch	21.5 ± 1.9	21.2 ± 0.7	57.3 ± 1.9	19.2	2.7 ± 0.2
(Kinmaze)	Amylopectin	2.3 ± 0.1	21.4 ± 0.5	59.6 ± 2.2	-	2.8 ± 0.2
ss1 ^L	Starch	21.0 ± 0.3	21.8 ± 0.5^,*	57.2 ± 0.3^,*	19.7	2.6 ± 0.1^,*
(i2-1)	Amylopectin	1.3 ± 0.0^*	21.2 ± 0.5^,*	59.1 ± 2.6^**	-	2.8 ± 0.0^,*
be2b	Starch	29.4 ± 0.8^**	34.3 ± 0.6^*	36.3 ± 0.4^*	28.1^,*	1.1 ± 0.0^*
(EM10)	Amylopectin	1.3 ± 0.1^*	35.8 ± 1.4^*	38.9 ± 1.5^*	-	1.1 ± 0.0^,*
ss1 ^L /be2b	Starch	21.6 ± 0.6	37.5 ± 1.2^***	40.9 ± 1.9^***	19.7	1.1 ± 0.0^***
(#4017)	Amylopectin	1.2 ± 0.1^***	37.8 ± 0.5^***	38.6 ± 1.0^***	-	1.0 ± 0.0^***

^aThree fractions (Fr. I, II and III) were divided at troughs of carbohydrate content curve, as detected by refractive index detectors (Figure 5).
^bTotal carbohydrate content = 100%.
^cAreas of Fr. II and Fr. III of amylopectin were superimposed onto those of the starch, and amount of amylopectin (extra-long chain) in Fr. I was calculated.
^dMean ± SE of three replicates.
^eTrue amylose content (TAC) = apparent amylose content (Fr. I of starch) – extra-long chains (Fr. I of amylopectin).
*Significant differences between single mutant and wild-type lines (t-test, P < 0.05).
**Significant differences between parental mutant and double mutant lines (t-test, P < 0.05).
***Significant differences between double mutant and wild-type lines (t-test, P < 0.05).

ISSN: 1471-2229