新型水稻57H突变体的发掘与表征

Excavation and Characterization of Novel Rice 57H Mutants

在正常型水稻的发育种子中,谷蛋白与醇溶蛋白在胚乳细胞内质网被合成后,作为主要储藏蛋白质分别被蓄积成液泡型蛋白体与内质网衍生型蛋白体。一些57H变异导致57kD谷蛋白前体高量增加与成熟型谷蛋白显著减少,是关于水稻储藏蛋白蓄积的基因突变。本研究采用SDS-PAGE技术,从水稻种质资源中,发现并获得2个57H突变体。种子全蛋白的SDS-PAGE分析显示,这2个突变体兼具57kD多肽链大量增加与13kD多肽链缺失的性状,但并没有成熟型谷蛋白等其他储藏蛋白性状的变化;谷蛋白电泳与免疫印染分析显示其高量增加的多肽链是57kD谷蛋白前体;醇溶蛋白电泳分析显示它们中缺失的多肽链是13kD醇溶蛋白。这些结果表明所得的2份突变体具有与已报道57H突变体不同的性状,它们可能含有关于储藏蛋白质合成表达的未知遗传信息,是全面阐明储藏蛋白合成蓄积遗传调控机制的有用素材。

Glutelins and prolamins, the main rice storage proteins, are synthesized in the ER and accumulated into the vacuolar protein body and the ER-derived protein body in endosperm cell of the developing seed of the wild type rice, respectively. Several 57H mutations have been found to cause the high increase of 57 kD glutelin precursor and the remarkable decrease of the mature glutelins, and involved in the accumulation of storage proteins in rice. In this study, two 57H mutants were newly found and ob- tained from rice germplasms using SDS-PAGE technique. SDS-PAGE analysis of the total seed proteins showed that the two mu- tants had the characters namely the great increase of 57 kD polypeptide and the lack of 13 kD polypeptide, but not alteration of characters for the mature glutelins and other storage proteins; Eleetrophoretie and immuno-blotting analyses of glutelin showed that the increased polypeptides was 57 kD glutelin precursor in the mutants; Electrophoretic analysis of prolamins showed that the lacked polypeptide was 13 kD prolamin in them. It is indicate that the two mutants have novel characters distinct from the re- ported 57H mutants. They probably contain unknown genetic information for synthesis and expression of storage proteins, and are considered to be useful materials for the overall understanding of genetic mechanism regulating synthesis and accumulation of the storage proteins in rice.