Microsatellites in starch-synthesizing genes in relation to starch physicochemical properties in waxy rice (Oryza sativa L.)
Microsatellites in starch-synthesizing genes in relation to starch physicochemical properties in waxy rice (Oryza sativa L.)
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DOI：
10.1007/s00122-002-1049-3
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发表时间：
2002-11-01
影响因子：
5.4
通讯作者：
Sun, M
中科院分区：
文献类型：
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作者：
Bao, JS;Corke, H;Sun, M
大米淀粉由直链淀粉和支链淀粉组成。直链淀粉含量是决定稻米淀粉品质的重要因素，主要受蜡质基因控制，编码颗粒结合淀粉合成酶(GBSS)。淀粉分支酶(SBE)和可溶性淀粉合成酶(SSS)在支链淀粉合成中起主要作用。以56份糯稻材料为材料，研究了编码颗粒结合淀粉合成酶1的Wx基因、编码淀粉分支酶I的SBE基因和编码可溶性淀粉合成酶1的SSS基因的微卫星多态性。在Wx基因座检测到4个(CT)(N)微卫星等位基因，分别为(CT)(16)、(CT)(17)、(CT)(18)和(CT)(19)，其中以(CT)(17)频率最高。在SBE基因座上发现了3类(CT)(N)微卫星等位基因，分别为(CT)(8)或(CT)(10)，并伴有CTCTCGGGCGA插入序列，以及(CT)(8)单独插入。在SSS基因座上有多个微卫星聚集。然而，这些等位基因也可以分为三类，即等位基因类SSS-A=(AC)(2)...TCC(TC)(11)...(TC)(5)C(ACC)(11)，等位基因类SSS-B=(AC)(3)...TCT(TC)(6)...(TC)(4)C(ACC)(9)，等位基因类SSS-C=(AC)(3)...TCT(TC)(6)...(TC)(4)C(ACC)(8)。不同微卫星基因型间的淀粉理化特性分析表明，携带(CT)(19)等位基因、SBEA等位基因和SSS-B等位基因的糯稻群体与其他群体有较大差异。糊化温度(GT)较高的15份材料(19份)中有9份属于WX(CT)(19份)，全部属于SBE-A类，13份属于SSS-B类。这些微卫星可能在水稻品质改良的分子标记辅助育种中发挥作用。
Rice starch is composed of amylose and amylopectin. Amylose content, an important determinant of rice starch quality, is primarily controlled by the waxy gene, encoding granule-bound starch synthase (GBSS). The starch branching enzyme (SBE) and soluble starch synthase (SSS) play major roles in the synthesis of amylopectin. Microsatellite polymorphisms in the three genes, the wx gene encoding granule-bound starch synthase 1, the SBE gene encoding starch branching enzyme I and the SSS gene encoding soluble starch synthase 1, were studied for 56 accessions of waxy rice (Oryza sativa L.). Four (CT)(n) microsatellite alleles, (CT)(16), (CT)(17), (CT)(18) and (CT)(19), at the wx locus were detected in this set of waxy rice, of which (CT)(17) was the most frequent. Three (CT)(n) microsatellite allele classes were found at the SBE locus, (CT)(8) or (CT)(10) together with an insertion sequence of CTCTCGGGCGA, and (CT)(8) alone without the insertion. There were multiple microsatellites clustered at the SSS locus. However, these alleles can also be grouped into three classes, i.e. the allele class SSS-A = (AC)(2)...TCC(TC)(11)...(TC)(5)C(ACC)(11), the allele class SSS-B = (AC)(3)...TCT(TC)(6)...(TC)(4)C(ACC)(9), and the allele class SSS-C = (AC)(3)...TCT(TC)(6)...(TC)(4) C(ACC)(8). The analyses of starch physicochemical properties among different microsatellite genotypes indicated that the waxy rice group with the (CT)(19) allele, the SBEA allele and the SSS-B allele was quite different from other groups. Nine out of 15 accessions with a high gelatinization temperature (GT)(19) belonged to the wx (CT)(19) group, all of them belonged to the SBE-A group and 13 of them belonged to the SSS-B group. These microsatellites might be useful in marker-assisted breeding for the improvement of rice grain quality.