Improvement of Abiotic Stress Tolerance of Crops Via Enhancement of their Antioxidant Capacity

Crops are often exposed to various environmental stresses, such as high and low temperature, drought, increase of field salinity, and metal toxicity. At cellular level, these stresses disturb redox homeostasis and trigger formation of reactive oxygen species (ROS). The improvement of the antioxidant defence system to attenuate the effects of ROS and to maintain the redox balance even under stress conditions may result in an enhanced stress tolerance of plants. Biotechnology efforts including direct gene transfer techniques or cell and tissue cultures have been applied for improving the abiotic stress tolerance of plants via the enhancement of their antioxidant capacity. In this review, we demonstrate that the doubled haploid (DH) technology, especially through androgenesis, is also a valuable tool for producing plants with enhanced antioxidant capacity tolerant to most kinds of abiotic stresses. The monitoring of changes in photosynthetic processes induced by environmental stresses can be efficiently applied for the characterization of the abiotic stress tolerance of selected DH plants. In addition, we demonstrate that the in vitro selection of microspores can provide a wide range of genetic plant materials with different combinations of elevated activities of antioxidant enzymes, which can contribute to the studying of stress tolerance mechanisms in relation also to the redox regulation.