693 / 2019-05-01 14:10:35

Heterologous expression of Arabidopsis thaliana Thioredoxin-h2 increased salt tolerance by enhancing antioxidant systems in Brassica napus

Salt tolerance,Thioredoxin-h2,Antioxidant system,Brassica napus,Arabidopsis thaliana,Heterologous expression

全体主题 > Abiotic Stress

Brassica napus is an important crop in food and energy industries producing vegetable oil and bio-diesel, respectively. When B. napus is exposed to excessive salt, it gives adverse effects resulting decrease of crop yield. Salt stress can not only cause secondary stresses, such as ionic toxicity and osmotic stress, but also induce secondary messengers, such as Ca2+ and reactive oxygen species (ROS), in plant cells. Accumulation of toxic ROS directly affects to plant cells with imbalance of redox system and triggers apoptosis. Thioredoxins (Trxs) are encoded by large gene family and play as antioxidant proteins. We isolated genes encoding two cytosolic h-type Arabidopsis Trx proteins including AtTrx-h2 and AtTrx-h3 which share high sequence identity without distinct N-terminal region of AtTrx-h2, and generated AtTrx overexpressing transgenic B. napus. Heterologous expression of AtTrx-h2 in B. napus conferred salt tolerance with high fresh weight and chlorophyll contents under salt stress, while that of AtTrx-h3 does not. Histochemical staining and H2O2 content showed that AtTrx-h2 transgenic plants were reduced ROS levels. In addition, activities of antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were higher in AtTrxh2 transgenic plants compared to vector control and AtTrx-h3 transgenic plants under salt stress. Therefore, we suggest that AtTrx-h2 could be a powerful genetic resource for developing of salt-tolerant crops.