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羊草是一种重要的禾本科牧草 ,主要分布于亚洲东部地区。硫氧化还原蛋白H (Trxh)是一大类广泛分布于动物、植物和微生物中的小分子蛋白。在一些禾本科植物中 ,一种在成熟花粉中表达的Trxh ,与植物的自交不亲和性有关。本研究克隆了羊草花粉硫氧还蛋白基因 (TrxLc)的DNA和cDNA序列 ,与其他禾本科植物Trxh的cDNA序列相比 ,它们具有 5 3.5 %～ 5 6 4 %的同源性。Southern杂交显示TrxLc在羊草基因组中是单拷贝。Northern杂交显示TrxLc在羊草根、茎和叶中没有表达 ,在成熟雌蕊和幼小花粉中微量表达 ,但是在成熟花粉中大量表达。在大肠杆菌中表达重组TrxLc并检测了其活性。胰岛素还原反应中得到的Vmax值和Km 值显示 ,TrxLc类似于其他植物的非花粉组织特异表达的Trxh ,但与大肠杆菌的Trxh差异较大。
Leymus chinensis is an important gramineous pasture, mainly distributed in eastern Asia. Thioredoxin H (Trxh) is a broad class of small molecule proteins widely found in animals, plants and microorganisms. In some grasses, one Trxh expressed in mature pollen is associated with plant self-incompatibility. In this study, we cloned the DNA and cDNA sequence of Leymus chinensis pollen thioredoxin gene (TrxLc), which shared 53.5% ~ 544% homology with the other cDNA sequences of Trxh. Southern blotting showed that TrxLc is a single copy in the Leymus chinensis genome. Northern blotting showed that TrxLc was undetectable in the roots, stems and leaves of Leymus chinensis and was slightly expressed in mature pistil and young pollen but abundant in mature pollen. Recombinant TrxLc was expressed in E. coli and tested for activity. The Vmax and Km values obtained in the insulin reduction reaction show that TrxLc is similar to Trxh that is specifically expressed in non-pollen tissues of other plants, but differs greatly from Trxh in Escherichia coli.