Protective Chemical Agents in the Amelioration of Plant Abiotic Stress

Biochemical and Molecular Perspectives

Aryadeep Roychoudhury, Durgesh K. Tripathi, Aryadeep Roychoudhury, Durgesh Kumar Tripathi, Aryadeep Roychoudhury, Durgesh Kumar Tripathi

• Publisher: Wiley-Blackwell
• Year: 2020
• Print ISBN: 9781119551638
• eBook ISBN: 9781119551652
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

A guide to the chemical agents that protect plants from various environmental stressors

Protective Chemical Agents in the Amelioration of Plant Abiotic Stress offers a guide to the diverse chemical agents that have the potential to mitigate different forms of abiotic stresses in plants. Edited by two experts on the topic, the book explores the role of novel chemicals and shows how using such unique chemical agents can tackle the oxidative damages caused by environmental stresses.

Exogenous application of different chemical agents or chemical priming of seeds presents opportunities for crop stress management. The use of chemical compounds as protective agents has been found to improve plant tolerance significantly in various crop and non-crop species against a range of different individually applied abiotic stresses by regulating the endogenous levels of the protective agents within plants. This important book:

• Explores the efficacy of various chemical agents to eliminate abiotic stress
• Offers a groundbreaking look at the topic and reviews the most recent advances in the field
• Includes information from noted authorities on the subject
• Promises to benefit agriculture under stress conditions at the ground level

Written for researchers, academicians, and scientists, Protective Chemical Agents in the Amelioration of Plant Abiotic Stress details the wide range of protective chemical agents, their applications, and their intricate biochemical and molecular mechanism of action within the plant systems during adverse situations.

1
Role of Proline and Glycine Betaine in Overcoming Abiotic Stresses

Murat Dikilitas¹, Eray Simsek¹, and Aryadeep Roychoudhury²

¹Department of Plant Protection, Faculty of Agriculture, Harran University, S. Urfa, Turkey

²Department of Biotechnology, St. Xavier's College (Autonomous), Kolkata, West Bengal, India

1.1 Introduction

Plants are continuously under exposures of many kinds of abiotic and biotic stresses starting from vegetative to reproductive stages (Roychoudhury et al., 2011; Hajihosseinlo et al., 2015; Aksakal et al., 2017; Aamer et al., 2018; Cheng et al., 2018; Dawood and El‐Awadi 2018; Duhan et al., 2018; Choudhary et al., 2019; Ghaffari et al., 2019; Sahitya et al., 2018; Paul and Roychoudhury 2019). Salinity, waterlogging, chilling or cold stress, drought, heat, light, heavy metal stress, pesticide wastes, nutrient deficiency, UV‐B damages, and pathogen stress and their combinations might lead to more devastating consequences on crop plants (Roychoudhury et al. 2011). Even if crop plants may exhibit tolerance to stress arising from either biotic or abiotic stress agents or to both, they may not be productive as desired in terms of crop production and quality. Although plants are able to accumulate osmolytes to defend themselves against stress, the synthesis of osmolytes could be reduced under severe stress conditions. In general, increases of osmolytes have been regarded as the reflection of stress tolerance. There are quite a few osmolytes commonly measured in cells such as proline, polyamines, glycine betaine (GB), sugar and sugar products, glycerol, sorbitol, mannitol, etc., that have significant roles in protecting cells from cell‐damaging stress factors (Chen and Jiang 2010; Rabbani and Choi 2018). Therefore, increasing amino acid or osmolyte contents under stress conditions would be a proper approach to tackle at least one of the stress factors. However, if one of the stress agents is biotic, the mechanisms for tolerance would be more complex due to the adaptation of attacking pathogens to these stressful conditions. It is possible that the pathogens may use the compounds having low molecular weights such as sugars, polyamines, or low‐molecular‐weight amino acids as substrates. These “ready to take‐in substrates” could even increase the virulence of the pathogens and result in more devastating effects on crop production. Therefore, modulation of abiotic stress tolerance under the combined stress conditions may not be satisfactory for crop plants. Applications of proline, sugar, and amino acid might increase the pathogen dissemination via secretion of secondary metabolites under abiotic or combined stress occurrences. For example, Dunn et al. (1998) reported that NaCl stress led to increased production of arginine levels and decreased phenylalanine ammonia lyase (PAL) activity in citrus plants, thus causing increased susceptibility to nematode attack caused by Tylenchulus semipenetrans. The authors also stated that the reduction in PAL activity due to an increase in arginine levels increased higher infection rates. It was concluded that the increased level of arginine following salinity stress led to reduction in host defense responses against the attacking mites. In another study, Mathur et al. (2013) stated that the elevated CO₂ (550 ppm) led to reduction in disease severity of Alternaria blight and downy mildew caused by Alternaria brassicae and Hyaloperonospora brassicae, respectively, in Brassica juncea cv. Pusa Tarak (mustard plants). They concluded that elevated CO₂ resulted in the accumulation of higher amounts of epicuticular wax with the increase of total phenolics and PAL activity levels, which might have enabled the mustard plants to resist the infection caused by those pathogens. A reduction in pore size and stomatal density with reduced stomatal conductance might have played significant roles in decreasing the disease index of downy mildew caused by H. brassicae, which is a stomata‐invading pathogen. However, the same authors also stated that the pathogenicity of Albugo candida, a causal agent for white rust infection, increased in the same plant. The authors suggested that three times higher sugar concentration levels than plants grown in ambient CO₂ might have played significant roles and led to higher incidence and severity of the white rust disease. Therefore, we have to consider the biotic stress cases while we aim to develop and improve the level of tolerance or resistance of crop plants under stress.

In this chapter, we mainly focus on the modulation of abiotic stress issues through proline and GB application, but we would discuss on the biotic stress involvement as well.

1.2 Responses of Crop Plants Under Abiotic Stresses

Abiotic stress factors significantly cause reductions in crop production and deteriorate the crop quality, which eventually results in the depletion of food source. In recent years, climate changes in terms of increase in air and surface temperatures along with the enhanced accumulation of CO₂ and the environmental pollution make the situation worse. The stress agents whether abiotic or biotic would disrupt the biochemical and molecular pathways of crop plants and physiologically deteriorate the functions of crop plants (Ramegowda and Senthil‐Kumar 2015; Dikilitas et al. 2018). Abiotic stress combinations or abiotic and biotic stress combinations cannot be easily solved because of their different characteristics. Although the generation of crop plants for multiple stress factors is an urgent need, the addition of different stressors in the present scenario as well as the evolution of pathogenic and insect races would make the development of resistant crop plants difficult. Many approaches have been adopted to eradicate stress in crop plants; however, none of them has achieved complete success in agricultural systems. Plant breeding, genetic modifications, or application of signaling molecules as well as pol...

Table of contents

• Cover
• Table of Contents
• List of Contributors
• 1 Role of Proline and Glycine Betaine in Overcoming Abiotic Stresses
• 2 Glycine Betaine and Crop Abiotic Stress Tolerance: An Update
• 3 Osmoprotective Role of Sugar in Mitigating Abiotic Stress in Plants
• 4 Sugars and Sugar Polyols in Overcoming Environmental Stresses
• 5 Ascorbate and Tocopherols in Mitigating Oxidative Stress
• 6 Role of Glutathione Application in Overcoming Environmental Stress
• 7 Modulation of Abiotic Stress Tolerance Through Hydrogen Peroxide
• 8 Exogenous Nitric Oxide‐ and Hydrogen Sulfide‐induced Abiotic Stress Tolerance in Plants
• 9 Role of Nitric Oxide in Overcoming Heavy Metal Stress
• 10 Protective Role of Sodium Nitroprusside in Overcoming Diverse Environmental Stresses in Plants
• 11 Role of Growth Regulators and Phytohormones in Overcoming Environmental Stress
• 12 Abscisic Acid Application and Abiotic Stress Amelioration
• 13 Role of Polyamines in Mitigating Abiotic Stress
• 14 Role of Melatonin in Amelioration of Abiotic Stress‐induced Damages
• 15 Brassinosteroids in Lowering Abiotic Stress‐mediated Damages
• 16 Strigolactones in Overcoming Environmental Stresses
• 17 Emerging Roles of Salicylic Acid and Jasmonates in Plant Abiotic Stress Responses
• 18 Multifaceted Roles of Salicylic Acid and Jasmonic Acid in Plants Against Abiotic Stresses
• 19 Brassinosteroids and Salicylic Acid as Chemical Agents to Ameliorate Diverse Environmental Stresses in Plants
• 20 Role of γ‐Aminobutyric Acid in the Mitigation of Abiotic Stress in Plants
• 21 Isoprenoids in Plant Protection Against Abiotic Stress
• 22 Involvement of Sulfur in the Regulation of Abiotic Stress Tolerance in Plants
• 23 Role of Thiourea in Mitigating Different Environmental Stresses in Plants
• 24 Oxylipins and Strobilurins as Protective Chemical Agents to Generate Abiotic Stress Tolerance in Plants
• 25 Role of Triacontanol in Overcoming Environmental Stresses
• 26 Penconazole, Paclobutrazol, and Triacontanol in Overcoming Environmental Stress in Plants
• 27 Role of Calcium and Potassium in Amelioration of Environmental Stress in Plants
• 28 Role of Nitric Oxide and Calcium Signaling in Abiotic Stress Tolerance in Plants
• 29 Iron, Zinc, and Copper Application in Overcoming Environmental Stress
• 30 Role of Selenium and Manganese in Mitigating Oxidative Damages
• 31 Role of Silicon Transportation Through Aquaporin Genes for Abiotic Stress Tolerance in Plants
• 32 Application of Nanoparticles in Overcoming Different Environmental Stresses
• Index
• End User License Agreement