Møgelsvang S, Simpson D J
Department of Physiology, Carlsberg Laboratory, Valby, Denmark.
Plant Mol Biol. 1998 Mar;36(4):541-52. doi: 10.1023/a:1005916427024.
The Russian barley cultivar Nevsky lacks gamma 3 hordein and accumulates most of its hordein in the lumen of the endoplasmic reticulum and only a minor portion in the vacuole. In wild type barley and all other temperate cereals, storage proteins are deposited in the vacuole. F1 crosses revealed that the Nevsky phenotype is recessive; but the extent of hordein accumulation in the endoplasmic reticulum in F2 endosperm lacking gamma 3 hordein was very much less than in the Nevsky parent. In order to study the Nevsky endosperm phenotype we have measured the levels of seven proteins and two mRNAs involved in protein folding in the ER lumen or ER to Golgi transport during endosperm development. The protein levels were unaltered in Nevsky as compared to the wild-type variety Bomi. When the levels of these seven proteins were correlated with the rate of hordein accumulation, four of these (HSP70, PDI, Sar1p and Sec18p) were consistently up-regulated with hordein synthesis. Accumulation of hordein in the endoplasmic reticulum appears to be determined by the absence of gamma 3 hordein, or the product of a gene closely linked to it, plus one or more other recessive genes.
俄罗斯大麦品种涅夫斯基缺乏γ-3醇溶蛋白，其大部分醇溶蛋白在内质网腔中积累，只有一小部分在液泡中积累。在野生型大麦和所有其他温带谷物中，贮藏蛋白沉积在液泡中。F1杂交表明，涅夫斯基表型是隐性的；但在缺乏γ-3醇溶蛋白的F2胚乳中，内质网中醇溶蛋白的积累程度远低于涅夫斯基亲本。为了研究涅夫斯基胚乳表型，我们测量了胚乳发育过程中参与内质网腔中蛋白质折叠或内质网到高尔基体运输的七种蛋白质和两种mRNA的水平。与野生型品种博米相比，涅夫斯基中这些蛋白质的水平没有改变。当这七种蛋白质的水平与醇溶蛋白的积累速率相关联时，其中四种（热休克蛋白70、蛋白二硫键异构酶、Sar1p和Sec18p）随着醇溶蛋白的合成而持续上调。内质网中醇溶蛋白的积累似乎是由γ-3醇溶蛋白或与其紧密连锁的基因的产物缺失，再加上一个或多个其他隐性基因决定的。
