Author
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Sandhu, Devinder |
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KAUNDAL, AMITA - University Of California |
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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 3/18/2018 Publication Date: 8/14/2018 Citation: Sandhu, D., Kaundal, A. 2018. Dynamics of salt tolerance: molecular perspectives. In: Gosal, S.S., Wani, S.H., editors. Biotechnologies of Crop Improvement. Volume 3. Cham, Switzerland: Springer International Publishing AG. p. 25-40. https://doi.org/10.1007/978-3-319-94746-4. DOI: https://doi.org/10.1007/978-3-319-94746-4 Interpretive Summary: Salinity is a common problem throughout the world and is among one of the most important abiotic stresses faced by plants. With the increasing global scarcity of irrigation water salinity problem is further pronounced. Salt stress adversely affects growth and development by inhibiting many metabolic processes. The salt stress affects the growth of a plant by limiting germination, leaf expansion, root/shoot growth, photosynthesis, stomatal conductance and nutrient uptake. All these factors ultimately affect the biomass and yield of the plant. Salt tolerance mechanism is a complex of various different pathways that work in coordination and are interdependent on each other. Plants develop several biochemical and physiological mechanisms to survive in high salinity environment. Some of the important aspects of salt stress and important mechanisms responsible for salt tolerance include tissue Na+ accumulation, Na+ exclusion from roots, sequestration of Na+ into vacuoles, enhanced tolerance to Na+ concentration, and Cl¯ toxicity. Traditional breeding approaches had limited success in identifying material tolerant to salinity due to the complexity of the salt tolerance mechanism. In the last decade, significant progress has been made in understanding plant responses to salinity and the roles of several important players involved have been elucidated. The focus of this book chapter is to discuss recent advances in identifying genetic components and possibility of their utilization in developing new salt-tolerant genotypes that are vigorous and high yielding. This chapter will be of interest to plant biologists who are working on understanding molecular control of the salt tolerance mechanism. In addition, insights from this work will be beneficial to plant breeders in developing salt tolerant varieties. Improving salt tolerance in plants will not only improve yield but will provide incentives to make augmented use of alternative/degraded waters, which may open up new lands for the crop cultivation. Technical Abstract: Plant being sessile has to face many environmental stresses and develop physiological and biochemical mechanisms to withstand those stresses. Salinity is one of the major stresses that affects the plant growth and impose direct impact on productivity and yield. The lack of good quality irrigation water is forcing farmers to use alternative or degraded waters of irrigation throughout the world. One of the major considerations for using alternate or degraded water is often its high salinity. Salinity affects various physiological and biochemical mechanisms in plants, including germination and growth, photosynthesis and plant water relations. Plants, when exposed to external stresses, develop mechanisms and responses to defend themselves. Salt tolerance is regulated by a complex network of different component traits. With the availability of the genome sequences of the most crop species, it became feasible to develop the links between physiological performance and underlying biological mechanisms involved in salinity stress. This article describes the effect of salinity on the plants such as germination, growth, photosynthesis and plant water relations, and mechanism plant adopt to protect itself such as ion exclusion from roots, sequestering ions into vacuole, and high tolerance to ion toxicity. Recent advances in research and technology may play critical role in developing new salt-tolerant cultivars that are vigorous and high yielding. |
