Characterization of pullulanase (PUL)-deficient mutants of rice (Oryza sativa L.) and the function of PUL on starch biosynthesis in the developing rice endosperm.
Characterization of pullulanase (PUL)-deficient mutants of rice (Oryza sativa L.) and the function of PUL on starch biosynthesis in the developing rice endosperm.
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DOI：
10.1093/jxb/ern349
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发表时间：
2009
影响因子：
6.9
通讯作者：
Nakamura Y
中科院分区：
文献类型：
--
作者：
Fujita N;Toyosawa Y;Utsumi Y;Higuchi T;Hanashiro I;Ikegami A;Akuzawa S;Yoshida M;Mori A;Inomata K;Itoh R;Miyao A;Hirochika H;Satoh H;Nakamura Y
水稻等位基因糖1(Sug1)异淀粉酶1(ISA1)缺陷突变体在胚乳中积累不同水平的淀粉和植物糖原，普鲁兰酶类型的脱分支酶(PUL)的活性与Sug1表型的严重程度密切相关。因此，我们选育了三个PUL缺失的突变体来研究PUL在淀粉生物合成中的作用。PUL活性的降低对参与淀粉生物合成的其他酶没有多效性影响。与野生型相比，Pu1突变体的支链淀粉短链(DP≤13)增加，但变化幅度远小于Sug1突变体。PUL突变体的α-葡聚糖组成[直链淀粉、支链淀粉、水溶性多糖]和淀粉组分(直链淀粉和支链淀粉)的结构基本相同，但突变体的支链淀粉B2-3链的平均链长比野生型长∼3个残基。Pul缺失突变体和轻度Sug1突变体之间的双突变体仍然保留了胚乳组织外层的淀粉，而支链淀粉的WSP和短链(DP≤7)的含量高于Sug1突变体，这表明Pul功能与Isa 1功能部分重叠，其缺失对支链淀粉合成的影响比Isa 1缺失要小得多，Sug1表型的变化对Pul活性的依赖不明显。
Rice (Oryza sativa) allelic sugary1 (sug1) mutants defective in isoamylase 1 (ISA1) accumulate varying levels of starch and phytoglycogen in their endosperm, and the activity of a pullulanase-type of a debranching enzyme (PUL) was found to correlate closely with the severity of the sug1 phenotype. Thus, three PUL-deficient mutants were generated to investigate the function of PUL in starch biosynthesis. The reduction of PUL activity had no pleiotropic effects on the other enzymes involved in starch biosynthesis. The short chains (DP ≤13) of amylopectin in PUL mutants were increased compared with that of the wild type, but the extent of the changes was much smaller than that of sug1 mutants. The α-glucan composition [amylose, amylopectin, water-soluble polysaccharide (WSP)] and the structure of the starch components (amylose and amylopectin) of the PUL mutants were essentially the same, although the average chain length of the B2-3 chains of amylopectin in the PUL mutant was ∼3 residues longer than that of the wild type. The double mutants between the PUL-null and mild sug1 mutants still retained starch in the outer layer of endosperm tissue, while the amounts of WSP and short chains (DP ≤7) of amylopectin were higher than those of the sug1 mutant; this indicates that the PUL function partially overlaps with that of ISA1 and its deficiency has a much smaller effect on the synthesis of amylopectin than ISA1 deficiency and the variation of the sug1 phenotype is not significantly dependent on the PUL activities.
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影响因子：
4.9
作者：
Fujita, N;Kubo, A;Nakamura, Y
通讯作者：
Nakamura, Y
影响因子：
7.4
作者：
Fujita, N;Yoshida, M;Nakamura, Y
通讯作者：
Nakamura, Y
影响因子：
7.4
作者：
Beatty, MK;Rahman, A;James, MG
通讯作者：
James, MG
影响因子：
11.6
作者：
Dinges, JR;Colleoni, C;Myers, AM
通讯作者：
Myers, AM
影响因子：
7.2
作者：
Burton, RA;Jenner, H;Denyer, K
通讯作者：
Denyer, K