Genetic Engineering Strategies for Abiotic Stress Tolerance in Plants

Abstract

Crop plants are affected by a variety of abiotic stresses such as salinity, drought, extreme temperatures, and oxidative stress and cause a significant yield loss (more than 50 %). In the near future, these abiotic stresses might increase because of global climate change. Abiotic stresses lead to dehydration or osmotic stress through reduced availability of water for vital cellular functions and maintenance of turgor pressure and also result in high production of reactive oxygen species (ROS). Plants are evolved with various mechanisms such as changes in cellular and metabolic processes to cope with the stress condition. Recent developments in molecular genetics have contributed greatly to our understanding of the biochemical and genetic basis of abiotic stress tolerance. This has led to the development of abiotic stress-tolerant plants with yield advantage by modulation of the expression of the genes that encode for enzymes involved in the biosynthesis of osmoprotectants (e.g., proline, sugars, sugar alcohol, glycine betaine, and polyamines), antioxidant enzymes, protective proteins (e.g., LEAs and HSPs), transporters, regulatory proteins, kinases, and transcription factors. More recently, posttranscriptional and posttranslational regulation mechanisms of the abiotic stress response, like microRNAs and ubiquitination, appear as promising new modulation targets to develop abiotic stress-tolerant plants and contribute to the development of more productive crops to feed the growing mass.