Biostimulants: Exploring Sources and Applications (Plant Life and Environment Dynamics)

Preface
Contents
About the Editors
1: Plant Biostimulants: Overview of Categories and Effects
	1.1 Introduction
	1.2 Sources of Biostimulants
	1.3 Humic Substance
	1.4 Smoke Water
	1.5 Protein Hydrolysates and Amino Acids
	1.6 Polysaccharides
	1.7 Inorganic Compounds
		1.7.1 Silicon (Si)
		1.7.2 Selenium (Se)
	1.8 Microorganisms
		1.8.1 Fungi
		1.8.2 Bacteria
	1.9 Seaweeds
	References
2: Biostimulant Potential of Seaweed Extracts Derived from Laminaria and Ascophyllum nodosum
	2.1 Introduction
	2.2 Historical and Traditional Uses as Fertilizers
	2.3 Biostimulant Uses
		2.3.1 Plant Growth
		2.3.2 Tolerance to Abiotic Stresses
		2.3.3 Resistance to Biotic Stresses
		2.3.4 Fruit Quality and Productivity
	2.4 Conclusion
	References
3: Borage Extracts as Biostimulants of Plant Growth and Development
	3.1 Plant Extracts
		3.1.1 Extraction Methods
		3.1.2 Plant Extract in Agriculture
	3.2 Borage as Biostimulant Source
		3.2.1 Taxonomical Classification
		3.2.2 Botanical Characteristics
		3.2.3 Origin and Cultivation
		3.2.4 Phytochemical Constituents
		3.2.5 Borage Uses
			3.2.5.1 Evaluation of Borage Extracts as Potential Biostimulants
	References
4: Simple Organic Acids as Plant Biostimulants
	4.1 Introduction
	4.2 Physiological Implications: Foliar Organic Acids as they Regulate Plant Growth and Development
		4.2.1 Malic Acid on Nitrogen Metabolism
		4.2.2 Root Exudation of Organic Acids
			4.2.2.1 Effect on Soil Flora and Fauna
		4.2.3 Nutrients Abortion
		4.2.4 Carbohydrate Partitioning
		4.2.5 Protein Metabolism
		4.2.6 Cell Membrane
		4.2.7 Morphogenesis
		4.2.8 Photosynthetic Parameters
			4.2.8.1 Foliar
			4.2.8.2 Added OA to Medium
		4.2.9 Antioxidative Capacity and Stress Tolerance
			4.2.9.1 Foliar OA
			4.2.9.2 Adding OA Medium
		4.2.10 Plant Defense
		4.2.11 Miscellaneous
	4.3 Agricultural Implications
		4.3.1 Yield Components
			4.3.1.1 Shoot
			4.3.1.2 Leaf
			4.3.1.3 Leaf Count
			4.3.1.4 Florescence Count
			4.3.1.5 Seed
			4.3.1.6 Oil Production
			4.3.1.7 Protein Content
			4.3.1.8 Root
			4.3.1.9 Bulb
			4.3.1.10 Fruit
				Flowering
		4.3.2 Stress Tolerance
			4.3.2.1 Abiotic Stress
				Salt and Drought Stress
				Heat Stress
				Chilling Stress
				Nutrients Toxicity
					Addition to Growth Medium
					Foliar Application
				Other Abiotic Stress
			4.3.2.2 Biotic Stress
		4.3.3 Postharvest Quality
			4.3.3.1 Oxalic Acid
			4.3.3.2 Citric Acid
			4.3.3.3 Malic Acid (L-Malic Acid)
			4.3.3.4 Other Combinations
		4.3.4 Secondary Metabolism and Essential Oil Production by Plants
		4.3.5 Quality Indices of Product
		4.3.6 Mineral Acquisition
		4.3.7 Other
	4.4 Conclusion
	References
5: Animal-Derived Hydrolyzed Protein and Its Biostimulant Effects
	5.1 Regulatory Status of Animal-Derived Hydrolyzed Protein, Production Methods, and Characteristics
		5.1.1 International Regulatory Status
		5.1.2 European Regulatory Status
		5.1.3 Production Processes
			5.1.3.1 Acid or Alkaline Hydrolysis
			5.1.3.2 Enzymatic Hydrolysis by Cell-Free Proteases
		5.1.4 Physicochemical Characteristics and Analysis Methods
			5.1.4.1 Raw Material Protein Chemistry
			5.1.4.2 Chemical Characteristics of Hydrolyzed Protein
			5.1.4.3 Analytical Methods
				Degree of Hydrolysis
				Racemization Degree
				Molecular Weight Distribution
				Determination of Free and Total Amino Acids
				Determination of Nitrogen
				Determination of Carbon
				Determination of Micro- and Macronutrients
	5.2 The Effects of Animal-Derived Hydrolyzed Protein on Crop Performance
		5.2.1 Plant Growth, Development, and Quality Traits
		5.2.2 Response to Stresses
		5.2.3 Nutrient Uptake and Assimilation
		5.2.4 Impact on Soil Properties
		5.2.5 Action Mechanisms of Hydrolyzed Protein: Experimental Evidences and Hypotheses
	5.3 Conclusions
	References
6: Protein Hydrolysates as Biostimulants of Plant Growth and Development
	6.1 Introduction
	6.2 Proteins from By-Products for Hydrolysates Production
	6.3 Fundamentals in Protein Hydrolysates Production
		6.3.1 Amino Acid Content and Profile Analysis
		6.3.2 Hydrolysis Degree
	6.4 Protein Hydrolysate Production
		6.4.1 Protein Substrates Treatment
		6.4.2 Enzymatic Proteolysis Performance
	6.5 Effects of PH-Based Biostimulant on Crops´ Traits
		6.5.1 Foliar and Radicular Administration of Hydrolysates
		6.5.2 Effects in Crop Growth and Quality
	6.6 Approaches to Elucidate PH Mode of Action
		6.6.1 High-Throughput Phenotyping Characterization
		6.6.2 Metabolomic Analysis
		6.6.3 Differential Gene Expression Analysis
	6.7 Conclusions
	References
7: Biostimulants and Their Extraction from Food and Agro-Based Industries
	7.1 Introduction
	7.2 Biostimulants from Food and Agro-Based Industries
	7.3 Modes of Action of Biostimulants from Organic Waste
	7.4 Extraction of Biostimulants from Food and Agro Waste
	7.5 Conclusion
	References
8: Foliar Application of Microbial and Plant-Based Biostimulants on Plant Nutrition
	8.1 Introduction
	8.2 Mode of Action of Biostimulants
	8.3 Plant Biostimulants on Crop Growth and Yield
	8.4 Implications of Biostimulants for Abiotic Stress Tolerances
	8.5 Enhancing Nutrient Uptake and Translocation
	8.6 Improving Nutrient Use Efficiency
	8.7 Improving Nutritional and Nutraceutical Quality of Plant Products
	References
9: The Role of Biostimulants in Plant Growth, Development, and Abiotic Stress Management: Recent Insights
	9.1 Introduction
	9.2 Biostimulants as Plant Growth and Development Regulators: An Efficient Agronomic Tool
		9.2.1 Abiotic Stress
	9.3 Abiotic Stress Management Through Biostimulants Application
		9.3.1 Salinity
		9.3.2 Drought
		9.3.3 Cold/Chilling Stress
		9.3.4 Heat Stress
		9.3.5 Heavy Metals
	9.4 Future Thrust and Conclusion
	References
10: Role of Biostimulants in Agriculture
	10.1 Introduction
	10.2 Main Categories of Biostimulants
		10.2.1 Humic Acid
		10.2.2 Protein Hydrolysates and Amino Acids
		10.2.3 Inorganic Compounds
		10.2.4 Chitosan and Other Biopolymers
		10.2.5 Microorganism
		10.2.6 Fulvic Acid
		10.2.7 Seaweed Extract
	10.3 Effects/Applications of Biostimulants in Different Crops
		10.3.1 Plant Growth, Yield, and Nutrient Efficiency
		10.3.2 Physiology and Metabolism
		10.3.3 Antioxidant Properties
		10.3.4 Stimulation of Plant Defences Against Abiotic Stresses
		10.3.5 Effect of Biostimulants on Physical Characteristics
		10.3.6 Effect on Chemical Composition
	10.4 Methods of Application
	10.5 Conclusion
	References
11: Biostimulants: Emerging Trend and Opportunities
	11.1 Introduction
	11.2 Microbial Biostimulants
		11.2.1 Mode of Action of Microbial Biostimulants
		11.2.2 Novel Approach in Microbial Biostimulants Development
	11.3 Protein Hydrolysates
		11.3.1 Mode of Action of Protein Hydrolysates
		11.3.2 Novel Approach in Protein Hydrolyzate Development
	11.4 Algae Extracts
		11.4.1 Production of Seaweeds
		11.4.2 Biostimulatory Action of Seaweed
		11.4.3 Novel Approach in Seaweed Extracts Development
	11.5 Humic Substances
		11.5.1 Humic Acids
		11.5.2 Fulvic Acids
		11.5.3 Humic Substances´ Effects
			11.5.3.1 Direct Effects
			11.5.3.2 Indirect Effects
		11.5.4 Concluding Remarks and Potential Future Research
	11.6 Conclusions and Perspectives
	References