硫氧还蛋白h(thioredoxin h,Trxh)是一类广泛存在于生物体内的多功能活性蛋白,分子量约为12kD,它通过还原靶蛋白中的二硫键参与酶活性调节、抗胁迫、信号传导等许多重要的生命活动。硫氧还蛋白h能促进谷物类种子萌发过程,主要表现在以下2个方面:(1)在籽粒萌发期间,硫氧还蛋白可通过还原储存蛋白的分子内二硫键使其更易于被降解;(2)硫氧还蛋白也可以直接地通过将酶还原或者间接地通过使酶抑制蛋白失活而激活酶。源于Phalaris coerulescens的trxs基因(thioredoxin s,trxs)与小麦硫氧还蛋白h基因(thioredoxin h,trxh)同属于硫氧还蛋白基因家族,它们的cDNA有94%的同源性,表达产物也有相似的生物功能。我们采用基因枪法将反义trxs基因导入小麦,获得了可稳定遗传的小麦,并检测出转基因种子中硫氧还蛋白h表达量、水溶蛋白和醇溶蛋白的还原状态以及a-淀粉酶活性均低于对照小麦;另外,通过模拟降雨抗穗发芽试验证实转基因株系具有很强的抗穗发芽能力。以转反义trxs基因抗穗发芽小麦为材料,检测反义trxs基因小麦籽粒萌发过程中蛋白质的变化,探讨转反义trxs基因小麦的抗穗发芽机理。研究表明反义trxs基因能够减缓KCl可溶性蛋白中Chloroform-methanol(CM)蛋白向代谢类蛋白的转化进程,在萌发初期降低籽粒代谢类蛋白的含量,使籽粒代谢速度下降,而CM蛋白主要包含一些分子量小于20kD的蛋白质。在籽粒成熟过程中,硫氧还蛋白能够阻止麦谷蛋白亚基形成谷蛋白聚合体的过程,在转基因小麦中麦谷蛋白更易于形成大分子量的谷蛋白大聚合体,使得转基因小麦中的谷蛋白在萌发初期更难于被水解,因此转基因小麦籽粒会因谷蛋白难于降解而萌发较慢。另外,反义trxs基因减慢了麦胚中10kD蛋白的降解过程。 Thioredoxin h (Thxh) is a kind of multifunctional active protein widely existing in the body. The molecular weight is about 12kD. It is involved in the regulation of enzyme activity, anti-stress and signal transduction by reducing the disulfide bond in the target protein Many other important life activities. Thioredoxin h can promote cereal seed germination process, mainly in the following two aspects: (1) during grain germination, thioredoxin can make it easier to be degraded by reducing the intramolecular disulfide bond of storage protein ; (2) Thioredoxin can also activate enzymes directly by reducing the enzyme or indirectly by inactivating the enzyme inhibitor. The trxs (trxs) from Phalaris coerulescens and the thioredoxin h (trxh) belong to the thioredoxin gene family. Their cDNAs have 94% homology and the expressed products also have Similar biological function. We introduced the antisense trxs gene into wheat by particle bombardment and obtained wheat with stable inheritance. We also detected the expression level of thioredoxin h, the reduced state of water-soluble protein and gliadin and the activity of a-amylase in the transgenic seeds Lower than the control wheat; In addition, by simulation rainfall-spike test confirmed transgenic lines have a strong resistance to spike germination. The antisense trxs gene-resistant sprouting wheat was used as the material to detect the changes of protein during the seed germination of antisense trxs and the mechanism of spike resistance of transgenic trxs transgenic wheat was studied. The results showed that the antisense trxs gene could slow down the conversion of Chloroform-methanol (CM) to the metabolic protein in the KCl-soluble protein, reduce the content of the metabolites in the early germination stage and decrease the metabolic rate of the grain, while the CM protein mainly contained some Protein with molecular weight less than 20kD. During grain maturation, thioredoxin can stop the gluten subunits from forming gluten polymers. In the transgenic wheat, glutenin is more likely to form large macromolecular gluten macromolecules such that gluten in the transgenic wheat Early germination is more difficult to be hydrolyzed, so GM wheat grains due to the degradation of gluten and germination is slower. In addition, the antisense trxs gene slows the degradation of 10 kD protein in wheat germ.