1st Edition
Physiology of Stressed Crops, Vol. 4 Osmoregulation and Protection
To cope with the abiotic stress-induced osmotic problems, plants adapt by either increasing uptake of inorganic ions from the external solution, or by de novo synthesis of organic compatible solutes acting as osmolytes. Of the osmoregulants and protectants discussed in this volume, trehalose, fructans, ectoine and citrulline, which are generated in different species, in osmotically ineffective amounts, mitigate the stress effects on cells/plants and improve productivity. There are several pieces of encouraging research discussed in this volume showing significant improvement in stress tolerance and in turn productivity by involving genetic engineering techniques.
Introduction to Osmoregulation: Introduction
Non-osmotic (Specific) Effects of Some Stress-induced Metabolits
Preconditioning
Osmoregulation and Environment
Inheritance of Osmotic Adjustment
Improvement Aspects
References
Measurement of Osmotic Adjustment
Suggested Readings
Inorganic Osmolytes: Introduction
The dominating role of potassium ion; K+-uptake mechanism
Sodium: Potassium uptake
The indirect role of calcium
Ion uptake as affected by different types of stresses
Improvement work
References; Brief descriptions of some procedures used
Patch-clamp method (Adopted from Lew, 1991)
Suggested readings
Sugars
The Key Osmolytes: Freeze-induced dehydration
Drought-induced dehydration
Salinity-induced dehydration
Sugars and dehydration-induced ROS
Toxic ion (arsenic) stress
High light-intensity stress; Heat stress
Sucrose and stress metabolism; References
Some procedures used
Suggested readings
Complex Sugars
Cyclitols
Introduction
Cold stress
Salinity stress
Drought stress
Nutrient stress
The stress of ROS
Improvement work
References
Brief description of some procedures used
Suggested readings
Proline: Introduction
Proline biosynthesis in stressed plants
Localization and transport
Stressinduced proline accumulation and stress mitigation
Salinity stress
Drought stress
Cold and freezing stress
Improvement
References
Some procedures used
Suggested reading
Glycinebetaine: Introduction
Biosynthesis in stressed plants
GB-induced mechanism of stress tolerance
Subcellular localization of GB
Stress induced GB accumulation and stress mitigation
Drought stress
Salinity stress
Cold stress
Heat stress
Oxidative stress
Improvement
Variability
Genetics/ Inheritance
Metabolic engineering
Practical application and future perspective
References
Brief description of some procedures used
Suggested reading
Polymines: Introduction
Biosynthesis
Polyamines and root growth
Stress tolerance
Improvement
References
Method used
HPLC analysis of polyamines (After Hennion and Martin-Tanguy, 2000)
Suggested readings
Trehalose: Introduction
Biosynthesis and sugar metabolism
Increased production of unstressed plants
Trehalose vs stress tolerance
Salinity stress
Drought stress
Improvement
Chloroplst vs nuclear engineering
Future perspective
References
Methods used
Detection of trehalose by HPLC with ELSD (Zhou et al., 2001)
Trehalase assay (After Jang et al., 2003)
Suggested reading
Fructan: Introduction
Biosynthesis
Abiotic stress tolerance
Hypoxia
Mineral nutrient stress
Salinity stress
Improvement
References
Suggested reading�Ectoine: Introduction
Biosynthesis
Transport
Engineering for ectoine production and improvement
References
Method used
Suggested reading
Citrulline: Introduction
Biosynthesis
Mechanism of Action
References
Method used
Suggested reading
ROS and Antioxidants: Introduction
ROS generation and ROS stress
The plant defence mechanism: Generation of ROS-degenerating enzymes and antioxidants
Enzymatic defence
Non-enzymatic defence
Stress induced ROS-detoxification by antioxidants
Cold stress
Heavy metal stress
References
Methods used (After Loggini et al., 1999)
Suggested readings
Biography
U S Gupta
