Effects of anti-sense thioredoxin s on grain yield and quality properties in two wheat cultivars with different quality types.

Thioredoxin h(Trxh) is a small protein catalyzing thiol-disulfide interchange,which is involved in many processes,such as activation or deactivation of enzymes and enzyme inhibition and germination.Wheat pre-harvest sprouting is caused by a series of hydrolyses,in which α-amylase plays a key role.The anti-trxs gene has been transferred into wheat(Triticum aestivum L.) cultivars "Yumai 18" and "Yumai 34" since 2003 to decrease Trxh reductive capability and α-amylase activity in wheat seed.From the T4 generations,two transgenic lines,TY18 and TY34 were obtained.To investigate the effects of anti-sense thioredoxin s on grain yield and quality properties,TY18 and TY34 were tested in field experiments in 2007-2009 growing seasons with comparisons to their cultivars Yumai 18(weak gluten) and Yumai 34(strong gluten).The result showed that the grain yield and quality properties of both lines were greatly affected.Compared with the wild controls,grain number per spike,grain yield and the starch quality in seeds of the transgenic lines were significantly promoted.The total starch content,amylopectin content,peak viscosity,trough viscosity,and final viscosity were significantly increased in transgenic lines,and the ratio amylase-to-amylopectin reduced,accordingly.The effects of transferring gene on protein quality were different in the two cultivars.The contents of total protein,albumin,globulin,and glutelin decreased significantly and the contents of gliadin increased significantly in the two transgenic lines of TY18.The development time and stability time of flour decreased significantly.However,these protein quality indexes had no significant differences between transgenic lines and controls,except contents of albumin,gliadin,and glutelin,which were decreased in transgenic lines TY34.Therefore,the anti-trxs gene transferred into wheat improved the starch quality of both wheat cultivars and the braking quality of weak-gluten cultivar.