Lecture 1 - Plant Water Relationship I - Botany PDF Download

 Page 1


Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
0 
                       
 
 
 
 
 
 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
Lesson: Water Relationship I 
Lesson Developer: Dr. Vibha Kaushik 
College/Dept: Swami Shraddhanand College, University of 
Delhi 
 
 
 
 
 
 
 
 
 
Page 2


Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
0 
                       
 
 
 
 
 
 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
Lesson: Water Relationship I 
Lesson Developer: Dr. Vibha Kaushik 
College/Dept: Swami Shraddhanand College, University of 
Delhi 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
1 
 
Chapter: Water Relationships I 
Table of Contents 
? Introduction 
? Properties of water which makes its transport possible 
? Cohesion 
? Adhesion 
? Surface tension 
? Tensile strength 
? Water potential and its components 
? Water potential 
? Components of water potential 
? Osmotic potential 
? Hydrostatic pressure  
? Gravitational component  
? Diffusion and Osmosis 
? Hypotonic solution 
? Hypertonic solution 
? Isotonic solution 
? Water absorption by roots 
? Apoplast 
? Symplast 
? Transmembrane pathway 
? Aquaporins 
? Root Pressure and Guttation 
? Ascent of sap 
? Root pressure theory 
? Capillarity theory 
? Cohesion-tension theory 
? Cavitation and embolism 
? Air seeding 
? Summary 
Page 3


Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
0 
                       
 
 
 
 
 
 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
Lesson: Water Relationship I 
Lesson Developer: Dr. Vibha Kaushik 
College/Dept: Swami Shraddhanand College, University of 
Delhi 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
1 
 
Chapter: Water Relationships I 
Table of Contents 
? Introduction 
? Properties of water which makes its transport possible 
? Cohesion 
? Adhesion 
? Surface tension 
? Tensile strength 
? Water potential and its components 
? Water potential 
? Components of water potential 
? Osmotic potential 
? Hydrostatic pressure  
? Gravitational component  
? Diffusion and Osmosis 
? Hypotonic solution 
? Hypertonic solution 
? Isotonic solution 
? Water absorption by roots 
? Apoplast 
? Symplast 
? Transmembrane pathway 
? Aquaporins 
? Root Pressure and Guttation 
? Ascent of sap 
? Root pressure theory 
? Capillarity theory 
? Cohesion-tension theory 
? Cavitation and embolism 
? Air seeding 
? Summary 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
2 
? Exercise 
? Glossary 
? Further Reading 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 4


Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
0 
                       
 
 
 
 
 
 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
Lesson: Water Relationship I 
Lesson Developer: Dr. Vibha Kaushik 
College/Dept: Swami Shraddhanand College, University of 
Delhi 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
1 
 
Chapter: Water Relationships I 
Table of Contents 
? Introduction 
? Properties of water which makes its transport possible 
? Cohesion 
? Adhesion 
? Surface tension 
? Tensile strength 
? Water potential and its components 
? Water potential 
? Components of water potential 
? Osmotic potential 
? Hydrostatic pressure  
? Gravitational component  
? Diffusion and Osmosis 
? Hypotonic solution 
? Hypertonic solution 
? Isotonic solution 
? Water absorption by roots 
? Apoplast 
? Symplast 
? Transmembrane pathway 
? Aquaporins 
? Root Pressure and Guttation 
? Ascent of sap 
? Root pressure theory 
? Capillarity theory 
? Cohesion-tension theory 
? Cavitation and embolism 
? Air seeding 
? Summary 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
2 
? Exercise 
? Glossary 
? Further Reading 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
3 
 
Learning outcomes 
This e-lesson has been written to enable the reader to understand: 
? The intricate and important relationship between plants and water.  
? What drives its absorption into the roots from soil 
? How it is translocated upwards from there 
? How effectively water is transported through the plant body and what are the driving 
forces.  
? The properties of water which make this tremendous task possible.  
? The basic concepts like water potential, diffusion and osmosis.  
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 5


Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
0 
                       
 
 
 
 
 
 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
Lesson: Water Relationship I 
Lesson Developer: Dr. Vibha Kaushik 
College/Dept: Swami Shraddhanand College, University of 
Delhi 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
1 
 
Chapter: Water Relationships I 
Table of Contents 
? Introduction 
? Properties of water which makes its transport possible 
? Cohesion 
? Adhesion 
? Surface tension 
? Tensile strength 
? Water potential and its components 
? Water potential 
? Components of water potential 
? Osmotic potential 
? Hydrostatic pressure  
? Gravitational component  
? Diffusion and Osmosis 
? Hypotonic solution 
? Hypertonic solution 
? Isotonic solution 
? Water absorption by roots 
? Apoplast 
? Symplast 
? Transmembrane pathway 
? Aquaporins 
? Root Pressure and Guttation 
? Ascent of sap 
? Root pressure theory 
? Capillarity theory 
? Cohesion-tension theory 
? Cavitation and embolism 
? Air seeding 
? Summary 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
2 
? Exercise 
? Glossary 
? Further Reading 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
3 
 
Learning outcomes 
This e-lesson has been written to enable the reader to understand: 
? The intricate and important relationship between plants and water.  
? What drives its absorption into the roots from soil 
? How it is translocated upwards from there 
? How effectively water is transported through the plant body and what are the driving 
forces.  
? The properties of water which make this tremendous task possible.  
? The basic concepts like water potential, diffusion and osmosis.  
 
 
 
 
 
 
 
 
 
 
 
 
 
Water relationship I 
 
 
Institute of lifelong learning, University of Delhi 
 
4 
 
Introduction 
Water comprises most of the body weight of all organisms and plants are no exception. Though 
its content may vary in different plant parts depending upon the extent of metabolic activity, 
water is essential for plant growth and survival, so much so, that water availability is the most 
important determinant of the type of vegetation in an area. Conversely, plants play a major role 
in the global circulation of water in the hydrological cycle. Plants, by the process of transpiration 
return 60% of the precipitation falling on ground, back to the atmosphere. 
Much of the living protoplasm of plant cells is water. It serves a wide array of functions ranging 
from simply maintaining the shape of the cell and its components, helping in growth, to, being a 
raw material for biochemical processes like photosynthesis and maintaining the temperature. 
Water is the major driving force for the process of growth. Cellular volume is enlarged by water 
uptake owing to the resulting increase in turgor pressure. Turgor pressure is an important 
phenomenon in plant cells which is responsible for several other processes also, like opening and 
closing of stomata, several plant movements, phloem translocation, etc. It is the phenomenon 
responsible for maintenance of rigidity and turgidity of plant tissues. 
The movement of water is said to occur through the soil-plant-atmosphere-continuum (SPAC). It 
mainly involves four steps listed in the flowchart below.