Sowokinos J R, Thomas C, Burrell M M
University of Minnesota, Department of Horticultural Science, St. Paul 55108, USA.
Plant Physiol. 1997 Feb;113(2):511-7. doi: 10.1104/pp.113.2.511.
UDP-glucose pyrophosphorylase (UGPase) was cloned from six American and nine European potato (Solanum tuberosum L.) cultivars. Restriction mapping of the different UGPase-cDNAs with BamHI, HindIII, and EcoRI revealed that at least two mRNA populations were present in most cultivars. Staining for UGPase activity in nondenaturing gels of proteins extracted from developing potato tubers yielded two major isozymes that were highly active and appeared to be dimeric in nature. Following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all isozymes were disassociated into a single subunit with a molecular mass of 53 kD. Since UGPase has been demonstrated to be a single-copy gene in the haploid genome of potato (A.Y. Borovkov, P.E. McClean, J.R. Sowokinos, S.H. Ruud, G.A. Secor [1995] J Plant Physiol 147: 644-652), there must be allelic differences at the UGPase locus (chromosome 11). The two alleles, designated ugpA and ugpB, were identified by the absence and presence of a BamHI site, respectively. The relative band intensities of the two cDNA populations following polymerase chain reaction amplification and agarose gel electrophoresis were related to a potato cultivar's ability to resist sweetening when exposed to cold temperatures.
从六个美国马铃薯品种和九个欧洲马铃薯（Solanum tuberosum L.）品种中克隆了尿苷二磷酸葡萄糖焦磷酸化酶（UGPase）。用BamHI、HindIII和EcoRI对不同的UGPase-cDNA进行限制性酶切图谱分析，结果表明大多数品种中至少存在两个mRNA群体。对从发育中的马铃薯块茎中提取的蛋白质进行非变性凝胶UGPase活性染色，产生了两种主要的同工酶，它们活性很高，且在本质上似乎是二聚体。经过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳后，所有同工酶都解离成一个分子量为53 kD的单一亚基。由于UGPase已被证明是马铃薯单倍体基因组中的单拷贝基因（A.Y. Borovkov、P.E. McClean、J.R. Sowokinos、S.H. Ruud、G.A. Secor [1995] J Plant Physiol 147: 644-652），因此在UGPase基因座（11号染色体）必定存在等位基因差异。分别根据BamHI位点的缺失和存在鉴定出两个等位基因，命名为ugpA和ugpB。聚合酶链反应扩增和琼脂糖凝胶电泳后两个cDNA群体的相对条带强度与马铃薯品种在低温下抗糖化的能力有关。
