Correlation Between Gene Expression and Antioxidant Enzyme Activity in Plants Tolerant to Water Stress: A Systematic Review

Drought stress is one of the main environmental factors that limit plant growth and productivity. In order to endure such stress, which increases every year, plants developed different strategies to withstand drought conditions, including an enzymatic antioxidant defense system with enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), peroxidase (POX), glutathione peroxidase (GPX), and glutathione-S-transferase (GST), among others, playing key roles. Therefore, efforts to develop new drought-tolerant varieties have become essential for maintaining human populations increasing researchers' interest in tools and/or mechanisms involved in drought tolerance. Thus, this work is aimed at offering a systematic review of the correlation between gene expression and antioxidant enzyme activity in water-stress tolerant plants for fourteen most important food crops worldwide, according to FAO, and Arabidopsis thaliana. This systematic review was performed using the free software StArt and the PICOS strategy. Among the factors that generate drought tolerance is the increased activity/gene expression of antioxidant enzymes. The use of plant regulators stood out as the most critical substance among chemical inputs; however, these do not provide long-term tolerance and therefore, the development of genetically modified organisms would be the most efficient technique for promoting tolerance to long-term water deficit in plants. In this systematic review, data was collected, and forty candidate genes were identified as responsible for water deficit tolerance, which can be used by plant breeding programs to develop genetically engineered products.