Breeding of low prolamin rice

低蛋白突变体的筛选从诱变处理的后代中筛选出慢蛋白突变体。在2000多个国家的水稻品种中检测到不同种类的原蛋白多肽。对低蛋白品种进行了杂交，并对后代进行了分析。低蛋白突变体esp2在小规模酿造试验中表现出低酸度和低氨基酸度，但溶出度非常高。研究结果将有助于材料的有效利用。低prolamin基因的分离低prolamin突变体的连锁分析结果表明，esp1基因位于4号染色体1.4 cM区域内。构建esp1基因的高密度连锁图谱。利用水稻品种“金麦斯”发育种子cDNA文库，克隆了与蛋白蛋白向PBI积累有关的PDI和BiP基因。基于cDNA克隆制备特异性抗体。低prolamin突变体的细胞化学分析prolamin包括两类，半胱氨酸残基贫乏的prolamin （Cys-P prolamin）和半胱氨酸残基丰富的prolamin （Cys-R prolamin）。低蛋白突变体esp3和Esp4的分析表明，Cys-R和Cys-P蛋白分别在种子发育的早期和后期积累到PBI中。各蛋白类抗体分析表明，Cys-P和Cys-R蛋白分别聚集在PBI的中心和外周。认为Cys-P蛋白在PBI中起核心作用，Cys-R在PBI中起填充作用。

Screening of low prolamin mutantsLow prolamin mutant lines were selected from the progeny of the mutagenesis treatment. The diverse variation for prolamin polypeptides were detected from the native rice varieties, about 2000, collected from some countries. The crossing among low prolamin varieties was done, the progeny is being analyzed.Brewing prosperity of low prolamin mutantThe low prolamin mutant, esp2, showed the low acid degree and low amino acid degree by small scale brewing test, though the mutant showed very high dissolving degree. The results will be helpful on the efficient utilization of the materials.Isolation of the gene for low prolaminBy the results of the linkage analysis of the low prolamin mutant, esp1 gene is positioned within the 1.4 cM region on chromosome 4. The high-density linkage map of esp1 gene will be constructed.The genes of PDI and BiP, related to the accumulation of the prolamin into PBI, were cloned using the cDNA library constructed from the developing seed of rice cultivar 'Kinmaze'. The specific antibodies were prepared based on the cDNA clone.Cytochemical analysis of the low prolamin mutantsProlamin consists of two classes, the cysteine residue poor prolamin (Cys-P prolamin) and the cysteine residue rich prolamin (Cys-R prolamin). The analysis of low prolamin mutants esp3 and Esp4 indicates that Cys-R and Cys-P prolamins are accumulated into PBI at the early and late stages, respectively, during seed development. The analysis by the antibodies to each prolamin classes indicates that Cys-P and Cys-R prolamins accumulate in the center and the periphery of PBI, respectively. It is thought that Cys-P prolamin plays an important role as a core and Cys-R plays the role of filling the inside of PBI.