Abiotic stress in algae: response, signaling and transgenic approaches

• Published in: Journal of applied phycology Vol. 34; no. 4; pp. 1843 - 1869
• Main Authors: Kaur, Manpreet, Saini, Khem Chand, Ojah, Hiramoni, Sahoo, Rajalakshmi, Gupta, Kriti, Kumar, Adesh, Bast, Felix
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2022; Springer Nature B.V
• Subjects: Abiotic factors; Abiotic stress; Algae; Algal growth; algology; Aquatic environment; Artificial environments; Biomedical and Life Sciences; Biosynthesis; Cell differentiation; chronic exposure; Community development; Dehydration; Desaturation; Desiccation; Differentiation (biology); Ecology; Freshwater & Marine Ecology; genetically modified organisms; growth and development; Heavy metals; Hormones; Life Sciences; Lipid metabolism; Lipids; Metabolites; Metals; Nutrient deficiencies; Nutrient deficiency; Nutrients; Photoinhibition; Photosynthesis; Physiology; Phytoplankton; Plant growth substances; Plant hormones; Plant Physiology; Plant Sciences; Primary production; primary productivity; Salinity; Salinity effects; Secondary metabolites; Signal transduction; Solutes; stress tolerance; Stresses; Survival; temperature; Ultraviolet radiation; Phytohormones; Transgenic; Lipid production; Abiotic stress; ROS; Salinity
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-022-02746-7

High salinity, nutrient deficiency, heavy metals, desiccation, temperature fluctuations, and ultraviolet radiations are major abiotic stress factors considered inhospitable to algal growth and development in natural and artificial environments. All these stressful conditions cause effects on algal physiology and thus biochemical functioning. For instance, long-term exposure to hyper/hypo salinity conditions inhibits cell differentiation and reduces growth. Photosynthesis is completely blocked in algae's dehydrated state, resulting in photoinhibition or photodamage. The limitation of nutrients in aquatic environments inhibits primary production via regulating phytoplankton community development and structure. Hence, in response to these stressful conditions, algae develop plenty of cellular, physiological, and morphological defences to survive and thrive. The conserved and generalized defence responses in algae include the production of secondary metabolites, desaturation of membrane lipids, activation of reactive species scavengers, and accumulation of compatible solutes. Moreover, a well-coordinated and timely response to such stresses involves signal perception and transduction mainly via phytohormones that could sustain algae growth under abiotic stress conditions. In addition, the combination of abiotic stresses and plant hormones could further elevate the biosynthesis of metabolites and enhance the ability of algae to tolerate abiotic stresses. This review aims to present different kinds of stressful conditions confronted by algae and their physiological and biochemical responses, the role of phytohormones in combatting these conditions, and, last, the future transgenic approaches for improving abiotic stress tolerance in algae.