Chapter 3 Biotechnology Strategies to Combat Plant Abiotic Stress Syed Uzma Jalil and Mohammad Israil Ansari Abstract Adverse environmental conditions cause major challenge to crop produc- tion and have significant decreases in crop yields worldwide. Developing stress toler- ance varieties against wide range of abiotic stresses is a widely supported approach that allows the environment to adapt to these methods. The reactive oxygen species (ROS) in plants are generated due to abiotic stresses that causes lipid peroxidation, inactivation of enzymes, DNA damage in plant cells. Biotechnological approaches propose numerous applications in crop improvement including stress resistance and quality enhancement. Identification and functional characterization of various target genes involves in signaling, transcription, antioxidant defense system for under- standing the molecular mechanism of abiotic stress tolerance has been employed to developed stress resistant plants by biotechnological techniques. Employing genetic engineering approaches, tissue culture techniques, functional validation of genes and transcription factors and genome editing approaches for example Zinc Finger Nucle- ases (ZFNs), transcription activator-like effector nucleases (TALENs) as well as advanced molecular tool CRISPR-Cas9 systems which provides simplicity and preci- sion of targeted gene editing methods. These biotechnological approaches engage in different processes to enhance abiotic stress resistant in different plants. Present chapter provide inclusive outline to draw the consideration of investigators with advances in biotechnological techniques to improve the tolerance of abiotic stresses in various plants to increase plant productivity. Keywords Abiotic stresses · Genetic engineering · Genome editing · Metabolic engineering · Stress tolerance S. U. Jalil Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow 226 028, India M. I. Ansari (B ) Department of Botany, University of Lucknow, Lucknow 226 007, India e-mail: ansari_mi@lkouniv.ac.in © Springer Nature Switzerland AG 2021 J. M. Al-Khayri et al. (eds.), Nanobiotechnology, https://doi.org/10.1007/978-3-030-73606-4_3 61