Transgenic Breeding Approaches for Improving Abiotic Stress Tolerance: Recent Progress and Future Perspectives

Abstract

The recent rapid climate changes and increasing global population have led to an increased incidence of abiotic stress and decreased crop productivity. Environmental stresses, such as temperature, drought, nutrient deficiency, salinity, and heavy metal stresses, are major challenges for agriculture, and they lead to a significant reduction in crop growth and productivity. Abiotic stress is a very complex phenomenon, involving a variety of physiological and biochemical changes in plant cells. Plants exposed to abiotic stress exhibit enhanced levels of ROS (reactive oxygen species), which are highly reactive and toxic and affect the biosynthesis of chlorophyll, photosynthetic capacity, and carbohydrate, protein, lipid, and antioxidant enzyme activities. Transgenic breeding offers a suitable alternative to conventional breeding to achieve plant genetic improvements. Over the last two decades, genetic engineering/transgenic breeding techniques demonstrated remarkable developments in manipulations of the genes for the induction of desired characteristics into transgenic plants. Transgenic approaches provide us with access to identify the candidate genes, miRNAs, and transcription factors (TFs) that are involved in specific plant processes, thus enabling an integrated knowledge of the molecular and physiological mechanisms influencing the plant tolerance and productivity. The accuracy and precision of this phenomenon assures great success in the future of plant improvements. Hence, transgenic breeding has proven to be a promising tool for abiotic stress improvement in crops. This review focuses on the potential and successful applications, recent progress, and future perspectives of transgenic breeding for improving abiotic stress tolerance and productivity in plants.

Recent Advances in Understanding Mechanisms of Plant Tolerance and Response to Aluminum Toxicity

“…Transgenic breeding is a promising tool for abiotic stress improvement in crops, which can create new and significant sources of resistance with rapid multiplication potentials [201]. In the previous decade, numerous studies were conducted to develop Al-tolerant crop cultivars through the manipulation of Al-tolerant genes, mainly concentrating on the secretion of OAs, Al sequestration, and defense system.…”

“…Plants improve stress resistance by regulating the expression of tolerant genes. The transformation of these genes can effectively improve Al tolerance of plants [201]. For example, AvSAMS1 is a multiple tolerance gene and transgenic Arabidopsis showed a higher tolerance to Al stress than Col-0 ecotype and also higher tolerance to other metal stresses [30].…”

Osmotic stress in banana is relieved by exogenous nitric oxide

“…Few strategies have been adopted to alleviate plants from drought stress, including developing drought-tolerant plants via conventional breeding, genetic engineering, introducing exogenous hormones, such as salicylic acid, or exogenous signaling molecules, such as nitric oxide. Conventional breeding, such as wide-cross hybridization and mutation breeding, and modern biotechnology, such as genetic engineering, were used to produce crop cultivars with various stress-tolerant traits ( Anwar & Kim, 2020 ). Exogenous application of signaling molecules, such as salicylic acid and nitric oxide, is a well-known stress mitigation strategy ( Chavoushi et al, 2019 ).…”

Abiotic Stress Responses in Plants: Current Knowledge and Future Prospects

“…However, one of the massive challenges in modern sustainable agriculture is the development of abiotic stressresilient crops with new and desired agronomical traits using different approaches. For this purpose, understanding the mechanisms by which plants perceive stress signals and further transmit them to cellular machinery for activating adaptive responses is of huge importance [13][14][15][16]. In this context, marrying the various physiological, biochemical, and gene regulatory network knowledge is essential that will aid up in the development of stress-tolerant high-yielding food crop cultivars [17,18].…”