Efnisyfirlit

• Cover Page
• Title page
• On the Cover
• Copyright page
• Editors
  • Editor Emeritus
  • Principle Contributors
• Preface
  • Organization
  • New to This Edition
  • Acknowledgments
  • Reviewers
• Digital Resources
  • Plant Physiology and Development, SEVENTH EDITION
    • For the Student
    • For the Instructor
    • Flexible Options
  • Note from The Authors
• Table of Contents
• UNIT I Structure and Information Systems of Plant Cells
  • 1 Plant and Cell Architecture
    • 1.1 Plant Life Processes: Unifying Principles
      • Plant life cycles alternate between diploid and haploid generations
    • 1.2 Overview of Plant Structure
      • Plant cells are surrounded by rigid cell walls
      • Plasmodesmata allow the free movement of molecules between cells
      • New cells originate in dividing tissues called meristems
    • 1.3 Plant Tissue Types
      • Dermal tissues cover the surfaces of plants
      • Ground tissues form the bodies of plants
      • Vascular tissues form transport networks between different parts of the plant
    • 1.4 Plant Cell Compartments
      • Biological membranes are lipid bilayers that contain proteins
        • Lipids
        • Proteins
    • 1.5 The Nucleus
      • Gene expression involves transcription, translation, and protein processing
      • Posttranslational modification of proteins determines their location, activity, and longevity
    • 1.6 The Endomembrane System
      • The endoplasmic reticulum is a network of internal membranes
      • Cell wall matrix polysaccharides, secretory proteins and glycoproteins are processed in the Golgi apparatus
      • The plasma membrane has specialized regions involved in membrane recycling
      • Vacuoles have diverse functions in plant cells
      • Oil bodies are lipid-storing organelles
      • Peroxisomes play specialized metabolic roles in leaves and seeds
    • 1.7 Independently Dividing Semiautonomous Organelles
      • Proplastids mature into specialized plastids in different plant tissues
      • Plastidial and mitochondrial division are independent of nuclear division in land plants
    • 1.8 The Plant Cytoskeleton
      • The plant cytoskeleton consists of microtubules and microfilaments
      • Actin, tubulin, and their polymers are in constant flux in the living cell
      • Microtubules are dynamic cylinders
      • Cytoskeletal motor proteins mediate cytoplasmic streaming and directed organelle movement
    • 1.9 Cell Cycle Regulation
      • Each phase of the cell cycle has a specific set of biochemical and cellular activities
      • The cell cycle is regulated by cyclins and cyclin-dependent kinases
      • Mitosis and cytokinesis involve both microtubules and the endomembrane system
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 2 Cell Walls: Structure, Formation, and Expansion
    • 2.1 Overview of Plant Cell Wall Functions and Structures
      • Plant cell walls vary in structure and function
      • Components differ for primary and secondary cell walls
      • Cellulose microfibrils have an ordered structure and are synthesized at the plasma membrane
      • Matrix polysaccharides are delivered to the wall via vesicles
      • Hemicelluloses are matrix polysaccharides that bind to cellulose
      • Pectins are hydrophilic gel-forming components of the primary cell wall
    • 2.2 The Dynamic Primary Cell Wall
      • Primary cell walls are continually assembled during cell growth
        • Self-Assembly
        • Enzyme-Mediated Assembly
    • 2.3 Mechanisms of Cell Expansion
      • Microfibril orientation influences growth directionality of cells with diffuse growth
      • Microfibril orientation in the multilayered cell wall changes over time
      • Cortical microtubules influence the orientation of newly deposited microfibrils
      • Many factors influence the extent and rate of cell growth
      • Stress relaxation of the cell wall drives water uptake and cell expansion
      • Leaf epidermal pavement cells provide a model for regulated cell wall expansion
      • Acid-induced growth and wall stress relaxation are mediated by expansins
      • Cell wall models are hypotheses about how molecular components fit together to make a functional wall
      • Many structural changes accompany the cessation of wall expansion
    • 2.4 Secondary Cell Wall Structure and Function
      • Secondary cell walls are rich in cellulose and hemicellulose and often have a hierarchical organization
        • Macrofibril Formation, Structure, and Adhesion
      • Lignification transforms the SCW into a hydrophobic structure resistant to deconstruction
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 3 Genome Structure and Gene Expression
    • 3.1 Nuclear Genome Organization
      • The nuclear genome is packaged into chromatin
      • Centromeres, telomeres, and nucleolar organizer regions contain repetitive sequences
      • Transposons are mobile sequences within the genome
      • Chromosome organization is not random in the interphase nucleus
      • Meiosis halves the number of chromosomes and allows for the recombination of alleles
      • Polyploids contain multiple copies of the entire genome
    • 3.2 Plant Cytoplasmic Genomes: Mitochondria and Plastids
    • 3.3 Transcriptional Regulation of Nuclear Gene Expression
      • RNA polymerase II binds to the promoter region of most protein-coding genes
      • Conserved nucleotide sequences signal transcriptional termination and polyadenylation
      • Epigenetic modifications help determine gene activity
    • 3.4 Posttranscriptional Regulation of Nuclear Gene Expression
      • All RNA molecules are subject to decay
      • Noncoding RNAs regulate mRNA activity via the RNA interference (RNAi) pathway
        • microRNAs Regulate Many Developmental Genes Posttranscriptionally
        • Short Interfering RNAs Originate from Repetitive DNA
        • Downstream Events of the RNAi Pathway Involve the Formation of an RNA-induced Silencing Complex
        • RNA-interference May Help Reset Epigenetic Marks in the Gametophyte
        • Small RNAs and RNAi Combat Viral Infection
        • Cosuppression Is a Gene-silencing Phenomenon Mediated by RNA
    • 3.5 Tools for Studying Gene Function
      • Mutant analysis can help elucidate gene function
      • Molecular techniques can measure the activity of genes
      • Gene fusions can create reporter genes
    • 3.6 Genetic Modification of Plants
    • 3.7 Editing Plant Genomes
      • Sequence-specific nucleases induce targeted mutations
      • Gene editing can lead to precise gene replacement
      • Base editing can be used as an alternative to homology-directed repair
      • Prime editing uses an RNA repair template and reverse transcription
    • 3.8 Engineering Crop Plants
      • Transgenes can confer resistance to herbicides or plant pests
      • Genetic engineering of plants remains controversial
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 4 Signals and Signal Transduction
    • 4.1 Temporal and Spatial Aspects of Signaling
    • 4.2 Signal Perception and Amplification
      • Receptors are located throughout the cell and are conserved across kingdoms
      • Signals must be amplified intracellularly to regulate their target molecules
      • Evolutionarily conserved MAP kinases amplify cellular signals
      • Evolutionarily conserved kinases regulate programmed and plastic plant development
      • Extracellular signals are perceived and transmitted by receptor-like kinases
      • Phosphatases are the “off switch” of protein phosphorylation
      • Other protein modifications can reconfigure cellular processes
      • Ca2+ is the most ubiquitous second messenger in plants and other eukaryotes
      • Changes in the cytosolic or cell wall pH can serve as second messengers for hormonal and stress responses
      • Reactive oxygen species act as second messengers mediating both environmental and developmental signals
      • Lipid signaling molecules act as second messengers that regulate a variety of cellular processes
    • 4.3 Hormones and Plant Development
      • Auxin was discovered in early studies of coleoptile bending during phototropism
      • Gibberellins promote stem growth and were discovered in relation to the “foolish seedling disease” of rice
      • Cytokinins were discovered as cell division–promoting factors in tissue-culture experiments
      • Ethylene is a gaseous hormone that promotes fruit ripening and other developmental processes
      • Abscisic acid regulates seed maturation and stomatal closure in response to water stress
      • Brassinosteroids regulate photomorphogenesis, germination, and other developmental processes
      • Strigolactones suppress branching and promote rhizosphere interactions
    • 4.4 Phytohormone Metabolism and Homeostasis
      • Indole-3-pyruvate is the primary intermediate in auxin biosynthesis
      • Gibberellins are synthesized by oxidation of the diterpene ent-kaurene
      • Cytokinins are adenine derivatives with isoprene side chains
      • Ethylene is synthesized from methionine via the intermediate ACC
      • Abscisic acid is synthesized from a carotenoid intermediate
      • Brassinosteroids are derived from the sterol campesterol
      • Strigolactones are synthesized from β-carotene
    • 4.5 Movement of Hormones within the Plant
      • Plant polarity is maintained by polar auxin streams
        • Auxin Uptake
        • Auxin Efflux
      • Auxin transport is regulated by multiple mechanisms
    • 4.6 Hormonal Signaling Pathways
      • The cytokinin and ethylene signal transduction pathways are derived from the bacterial two-component regulatory system
      • Receptor-like kinases mediate brassinosteroid and certain auxin signaling pathways
      • The core ABA signaling components include phosphatases and kinases
      • Plant hormone signaling pathways generally employ negative regulation
      • Several plant hormone receptors include components of the ubiquitination machinery and mediate signaling via protein degradation
      • Plants have evolved mechanisms for switching off or attenuating signaling responses
      • The cellular response output to a signal is often tissue-specific
      • Hormone responses are modulated by other endogenous molecules
      • Plants use electrical signaling for communication between tissues
      • Cross-regulation allows signal transduction pathways to be integrated
    • Summary
    • Suggested Reading
    • List of Key Terms
• UNIT II Transport and Translocation of Water and Solutes
  • 5 Water and Plant Cells
    • 5.1 Water in Plant Life
    • 5.2 The Structure and Properties of Water
      • Water is a polar molecule that forms hydrogen bonds
      • Water is an excellent solvent
      • Water has distinctive thermal properties relative to its size
      • Water has a high surface tension
      • Water has a high tensile strength
    • 5.3 Diffusion and Osmosis
      • Diffusion is the net movement of molecules by random thermal agitation
      • Diffusion is most effective over short distances
      • Osmosis describes the net movement of water across a selectively permeable barrier
    • 5.4 Water Potential
      • The chemical potential of water represents the free-energy status of water
      • Three major factors contribute to water potential
        • Solutes
        • Pressure
        • Gravity
      • Water potentials can be measured
    • 5.5 Water Potential of Plant Cells
      • Water enters the cell along a water potential gradient
      • Water can also leave the cell in response to a water potential gradient
      • Water potential and its components vary with growth conditions and location within the plant
    • 5.6 Cell Wall and Membrane Properties
      • Small changes in plant cell volume cause large changes in turgor pressure
      • The rate at which cells gain or lose water is influenced by plasma membrane hydraulic conductivity
      • Aquaporins facilitate the movement of water across membranes
    • 5.7 Plant Water Status
      • Physiological processes are affected by plant water status
      • Solute accumulation helps cells maintain turgor and volume
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 6 Water Balance of Plants
    • 6.1 Water in the Soil
      • Soil water potential is affected by solutes, surface tension, and gravity
      • Water moves through the soil by bulk flow
    • 6.2 Water Absorption by Roots
      • Water moves in the root via the apoplast, symplasm, and transmembrane pathways
      • Solute accumulation in the xylem can generate “root pressure”
    • 6.3 Water Transport through the Xylem
      • The xylem consists of two types of transport cells
      • Water moves through the xylem by pressure-driven bulk flow
      • Water movement through the xylem requires a smaller pressure gradient than movement through living cells
      • What pressure difference is needed to lift water 100 meters to a treetop?
      • The cohesion–tension theory explains water transport in the xylem
      • Xylem transport of water in trees faces physical challenges
      • Plants have several mechanisms to overcome losses of xylem conductivity caused by embolism
    • 6.4 Water Movement from the Leaf to the Atmosphere
      • Leaves have a large hydraulic resistance
      • The driving force for transpiration is the difference in water vapor concentration
      • Water loss is also affected by the pathway resistances
      • Stomatal control couples leaf transpiration to leaf photosynthesis
      • The cell walls of guard cells have specialized features
      • Changes in guard cell turgor pressure cause stomata to open and close
      • Internal and external signals regulate the osmotic balance of guard cells
      • The transpiration ratio measures the relationship between water loss and carbon gain
    • 6.5 Overview: The Soil–Plant–Atmosphere Continuum
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 7 Mineral Nutrition
    • 7.1 Essential Nutrients, Deficiencies, and Plant Disorders
      • Special techniques are used in nutritional studies
      • Nutrient solutions can sustain rapid plant growth
      • Mineral deficiencies disrupt plant metabolism and function
        • Group 1: Deficiencies in Mineral Nutrients that are part of Carbon Compounds
        • Nitrogen
        • Sulfur
        • Phosphorus
        • Group 2: Deficiencies in Mineral Nutrients that are Important for Structural Integrity
        • Silicon
        • Boron
        • Group 3: Deficiencies in Mineral Nutrients that Remain in Ionic Form
        • Potassium
        • Calcium
        • Magnesium
        • Chlorine
        • Zinc
        • Sodium
        • Group 4: Deficiencies in Mineral Nutrients That are Involved in Redox Reactions
        • Iron
        • Manganese
        • Copper
        • Nickel
        • Molybdenum
      • Plant tissue analysis reveals mineral deficiencies
    • 7.2 Treating Nutritional Deficiencies
      • Crop yields can be improved by the addition of fertilizers
      • Some mineral nutrients can be absorbed by leaves
    • 7.3 Soil, Roots, and Microbes
      • Negatively charged soil particles affect the adsorption of mineral nutrients
      • Soil pH affects nutrient availability, soil microbes, and root growth
      • Excess mineral ions in the soil limit plant growth
      • Some plants develop extensive root systems
      • Root systems differ in form but are based on common structures
      • Different areas of the root absorb mineral ions differently
      • Nutrient availability influences root growth and development
      • Mycorrhizal symbioses facilitate nutrient uptake by roots
      • Nutrients move between mycorrhizal fungi and root cells
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 8 Solute Transport
    • 8.1 Passive and Active Transport
    • 8.2 Transport of Ions across Membrane Barriers
      • Different diffusion rates for cations and anions produce diffusion potentials
      • How does membrane potential relate to ion distribution?
      • The Nernst equation distinguishes between active and passive transport
      • Proton transport is a major determinant of the membrane potential
    • 8.3 Membrane Transport Processes
      • Channels enhance diffusion across membranes
      • Carriers bind and transport specific substances
      • Primary active transport requires energy
      • Secondary active transport is driven by ion gradients
      • Kinetic analyses can elucidate transport mechanisms
    • 8.4 Membrane Transport Proteins
      • Genes encoding many transporters have been identified
      • Transporters exist for diverse nitrogen-containing compounds
      • Cation transporters are diverse
        • Cation Channels
        • Cation Carriers
        • Cation Function in Cells
      • Anion transporters have been identified
      • Transporters for metal and metalloid ions transport essential micronutrients
      • Aquaporins have diverse functions
      • Plasma membrane H+-ATPases are highly regulated P-type ATPases
      • The tonoplast H+-ATPase drives solute accumulation in vacuoles
      • H+-pyrophosphatases and P-type H+-ATPases also pump protons at the tonoplast
    • 8.5 Transport in Stomatal Guard Cells
      • Blue light induces stomatal opening
      • Abscisic acid and high CO2 induce stomatal closing
    • 8.6 Ion Transport in Roots
      • Solutes move through both apoplast and symplasm
      • Ions cross both symplasm and apoplast
      • Xylem parenchyma cells participate in xylem loading
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
• UNIT III Biochemistry and Metabolism
  • 9 Photosynthesis: The Light Reactions
    • 9.1 Photosynthesis in Green Plants
    • 9.2 General Concepts
      • Light consists of photons with characteristic energies
      • Absorption of photosynthetically active light changes the electronic states of chlorophylls
      • Photosynthetic pigments absorb the light that powers photosynthesis
    • 9.3 Key Experiments in Understanding Photosynthesis
      • Action spectra relate light absorption to photosynthetic activity
      • Photosynthesis takes place in complexes containing light-harvesting antennas and photochemical reaction centers
      • The chemical reaction of photosynthesis is driven by light
      • Light drives the reduction of NADP+ and the formation of ATP
      • Oxygen-evolving organisms have two photosystems that operate in series
    • 9.4 Organization of the Photosynthetic Apparatus
      • The chloroplast is the site of photosynthesis
      • Thylakoids contain integral membrane proteins
      • Photosystems I and II are spatially separated in the thylakoid membrane
      • Anoxygenic photosynthetic bacteria have a single reaction center
    • 9.5 Organization of Light-Absorbing Antenna Systems
      • Antenna systems contain chlorophyll and are membrane-associated
      • The antenna funnels energy to the reaction center
      • Many antenna pigment–protein complexes have a common structural motif
    • 9.6 Mechanisms of Electron Transport
      • Electrons from chlorophyll travel through the carriers organized in the Z scheme
      • Energy is captured when an excited chlorophyll reduces an electron acceptor molecule
      • The reaction center chlorophylls of the two photosystems absorb at different wavelengths
      • The PSII reaction center is a multi-subunit pigment–protein complex
      • Water is oxidized to oxygen by PSII
      • Pheophytin and two quinones accept electrons from PSII
      • Electron flow through the cytochrome b6f complex also transports protons
      • Plastocyanin carries electrons between the cytochrome b6f complex and photosystem I
      • The PSI reaction center oxidizes PC and reduces ferredoxin, which transfers electrons to NADP+
      • Some herbicides block photosynthetic electron flow
    • 9.7 Proton Transport and ATP Synthesis in the Chloroplast
      • Cyclic electron flow augments the output of ATP to balance the chloroplast energy budget
    • 9.8 Repair and Regulation of the Photosynthetic Machinery
      • Carotenoids serve as photoprotective agents
      • Some xanthophylls also participate in energy dissipation
      • The PSII reaction center is easily damaged and rapidly repaired
      • Thylakoid stacking permits energy partitioning between the photosystems
    • 9.9 Genetics, Assembly, and Evolution of Photosynthetic Systems
      • Chloroplast genes exhibit non-Mendelian patterns of inheritance
      • Most chloroplast proteins are imported from the cytoplasm
      • The biosynthesis and breakdown of chlorophyll are complex pathways
      • Complex photosynthetic organisms have evolved from simpler forms
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 10 Photosynthesis: The Carbon Reactions
    • 10.1 The Calvin–Benson Cycle
      • The Calvin–Benson cycle has three phases: carboxylation, reduction, and regeneration
      • The fixation of CO2 via carboxylation of ribulose 1,5-bisphosphate and the reduction of 3-phosphoglycerate yield triose phosphates
      • The regeneration of ribulose 1,5-bisphosphate ensures the continuous assimilation of CO2
      • An induction period precedes the steady state of photosynthetic CO2 assimilation
      • Many mechanisms regulate the Calvin–Benson cycle
      • Rubisco activase regulates the catalytic activity of Rubisco
        • Rubisco Activase
      • Light regulates the Calvin–Benson cycle via the ferredoxin–thioredoxin system
      • Light-dependent ion movements modulate enzymes of the Calvin–Benson cycle
      • Light controls the assembly of chloroplast enzymes into supramolecular complexes
    • 10.2 The Oxygenation Reaction of Rubisco and Photorespiration
      • The oxygenation of ribulose 1,5-bisphosphate sets in motion photorespiration
      • Photorespiration is linked to the photosynthetic electron transport system
      • Enzymes of plant photorespiration derive from different ancestors
      • Photorespiration interacts with many metabolic pathways
    • 10.3 Inorganic Carbon–Concentrating Mechanisms
    • 10.4 Inorganic Carbon–Concentrating Mechanisms: C4 Photosynthetic Carbon Fixation
      • Malate and aspartate are the primary carboxylation products of the C4 cycle
      • Kranz-type C4 plants assimilate CO2 by the concerted action of two different types of cells
      • The C4 subtypes use different mechanisms to decarboxylate four-carbon acids transported to bundle sheath cells
      • Bundle sheath cells and mesophyll cells exhibit anatomical and biochemical differences
      • The C4 cycle also concentrates CO2 in single cells
      • Light regulates the activity of key C4 enzymes
      • Photosynthetic assimilation of CO2 in C4 plants requires more transport processes than in C3 plants
      • In hot, dry climates, the C4 cycle reduces photorespiration
    • 10.5 Inorganic Carbon–Concentrating Mechanisms: Crassulacean Acid Metabolism (CAM)
      • Different mechanisms regulate C4 PEPCase and CAM PEPCase
      • CAM is a versatile mechanism sensitive to environmental stimuli
    • 10.6 Accumulation and Partitioning of Photosynthates—Starch and Sucrose
    • 10.7 Formation and Mobilization of Chloroplast Starch
      • Chloroplast stroma accumulates starch as insoluble granules during the day
      • Starch degradation at night requires the phosphorylation of amylopectin
      • The export of maltose prevails in the nocturnal breakdown of transitory starch
      • The synthesis and degradation of the starch granule are regulated by multiple mechanisms
        • Redox Control
        • Protein Phosphorylation
        • Formation of Complexes with Proteins
        • Allosteric Effectors (Low Molecular Weight Metabolites)
    • 10.8 Sucrose Biosynthesis and Signaling
      • Triose phosphates from the Calvin–Benson cycle build up the cytosolic pool of three important hexose phosphates in the light
      • Fructose 2,6-bisphosphate regulates the hexose phosphate pool in the light
      • Sucrose is continuously synthesized in the cytosol
      • Sucrose plays only a minor role in stomatal regulation
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 11 Photosynthesis: Physiological and Ecological Considerations
    • 11.1 Photosynthesis Is Influenced by Leaf Properties
      • Leaf anatomy and canopy structure optimize light absorption
      • Leaf angle and leaf movement can control light absorption
      • Leaves acclimate to sun and shade environments
    • 11.2 Effects of Light on Photosynthesis in the Intact Leaf
      • Photosynthetic light-response curves reveal differences in leaf properties
      • Leaves must dissipate excess light energy as heat
        • The Xanthophyll Cycle
        • Chloroplast Movements
        • Leaf Movements
      • Absorption of too much light can lead to photoinhibition
    • 11.3 Effects of Temperature on Photosynthesis in the Intact Leaf
      • Leaves must dissipate vast quantities of heat
      • There is an optimal temperature for photosynthesis
      • Photosynthesis is sensitive to both high and low temperatures
      • Photosynthetic efficiency is temperature-sensitive
    • 11.4 Effects of Carbon Dioxide on Photosynthesis in the Intact Leaf
      • Atmospheric CO2 concentration keeps rising
      • CO2 diffusion to the chloroplast is essential to photosynthesis
      • CO2 supply imposes limitations on photosynthesis
        • C3 versus C4 plants
        • CAM plants
      • How will photosynthesis and respiration change in the future under elevated CO2 conditions?
    • 11.5 Stable Isotopes Record Photosynthetic Properties
      • How do we measure the stable carbon isotopes of plants?
      • Why does the carbon isotope ratio vary in plants?
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 12 Translocation in the Phloem
    • 12.1 Patterns of Translocation: Source to Sink
    • 12.2 Pathways of Translocation
      • Sugar is translocated in phloem sieve elements
      • Mature sieve elements are living cells specialized for translocation
      • Large pores in cell walls are the prominent feature of sieve elements
      • Companion cells aid the highly specialized sieve elements
    • 12.3 Phloem Loading
      • Phloem loading can occur via the apoplast or symplasm
      • Apoplastic loading is characteristic of many herbaceous species
      • Sucrose loading in the apoplastic pathway requires metabolic energy
      • Phloem loading in the apoplastic pathway involves a sucrose–H+ symporter
      • Transfer cells are companion cells that are specialized for membrane transport
      • Phloem loading is symplasmic in some species
      • The oligomer-trapping model explains symplasmic loading in plants with intermediary-type companion cells
      • Phloem loading is passive in several tree species
      • The type of phloem loading is correlated with several significant characteristics
    • 12.4 Long-Distance Transport: A Pressure-Driven Mechanism
      • Mass transfer is much faster than diffusion
      • The pressure-flow model is a passive mechanism for phloem transport
      • The pressure is osmotically generated
      • Some predictions of pressure flow have been confirmed, while others require further experimentation
      • Functional sieve plate pores appear to be open channels
      • Are the pressure gradients in the sieve elements sufficient to drive phloem transport in trees?
      • Modified models for translocation by mass flow have been suggested
      • Does translocation in gymnosperms involve a different mechanism?
    • 12.5 Materials Translocated in the Phloem
      • Sugars are translocated in a nonreducing form
      • Other small organic solutes are translocated in the phloem
      • Phloem-mobile macromolecules often originate in companion cells
      • Damaged sieve elements are sealed off
    • 12.6 Phloem Unloading and Sink-to-Source Transition
      • Phloem unloading and short-distance transport can occur via symplasmic or apoplastic pathways
      • Symplasmic unloading supplies growing vegetative sinks
      • Symplasmic unloading is passive but depends on energy consumption in the sink
      • Import into seeds, fruits, and storage organs often involves an apoplastic step
      • Apoplastic import is active and requires metabolic energy
      • The transition of a leaf from sink to source is gradual
    • 12.7 Photosynthate Distribution: Allocation and Partitioning
      • Allocation includes storage, utilization, and transport
      • Source leaves regulate allocation
      • Various sinks partition transport sugars
      • Sink tissues compete for available translocated photosynthate
      • Sink strength depends on sink size and activity
      • The source adjusts over the long term to changes in the source-to-sink ratio
    • 12.8 Transport of Signaling Molecules
      • Turgor pressure and chemical signals coordinate source and sink activities
      • Mobile RNAs function as signal molecules in the phloem to regulate growth and development
      • Mobile proteins also function as signal molecules to regulate growth and development
      • Plasmodesmata function in phloem signaling 
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 13 Respiration and Lipid Metabolism
    • 13.1 Overview of Plant Respiration
    • 13.2 Glycolysis
      • Glycolysis metabolizes carbohydrates from several sources
      • The energy-conserving phase of glycolysis produces pyruvate, ATP, and NADH
      • Plants have alternative glycolytic reactions
      • In the absence of oxygen, fermentation regenerates the NAD+ needed for glycolytic ATP production
    • 13.3 The Oxidative Pentose Phosphate Pathway
      • The oxidative pentose phosphate pathway produces NADPH and biosynthetic intermediates
      • The oxidative pentose phosphate pathway is controlled by cellular redox status
    • 13.4 The Tricarboxylic Acid Cycle
      • Mitochondria are semiautonomous organelles
      • Pyruvate enters the mitochondrion and is oxidized via the TCA cycle
      • The TCA cycle of plants has unique features
    • 13.5 Oxidative Phosphorylation
      • The electron transport chain catalyzes a flow of electrons from NADH to O2
        • Complex I (NADH Dehydrogenase)
        • Complex II (Succinate Dehydrogenase)
        • Complex III (Cytochrome bc11 Complex)
        • Complex IV (Cytochrome cc Oxidase)
      • The electron transport chain has supplementary branches
      • ATP synthesis in the mitochondrion is coupled to electron transport
      • Transporters exchange substrates and products
      • Aerobic respiration yields about 60 molecules of ATP per molecule of sucrose
      • Several subunits of respiratory complexes are encoded by the mitochondrial genome
      • Plants have several mechanisms that lower the ATP yield
        • The Alternative Oxidase
        • The Uncoupling Protein
        • Rotenone-Insensitive NAD(P)H Dehydrogenases
      • Respiration is an integral part of a redox and biosynthesis network
      • Respiration is controlled at multiple levels
    • 13.6 Respiration in Intact Plants and Tissues
      • Plants respire roughly half of the daily photosynthetic yield
      • Respiratory processes operate during photosynthesis
      • Different tissues and organs respire at different rates
      • Environmental factors alter respiration rates
        • Oxygen
        • Temperature
        • Carbon Dioxide
    • 13.7 Lipid Metabolism
      • Fats and oils store large amounts of energy
      • Triacylglycerols are stored in oil bodies
      • Polar glycerolipids are the main structural lipids in membranes
      • Fatty acid biosynthesis consists of cycles of two-carbon addition
      • Glycerolipids are synthesized in the plastids and the ER
      • Lipid composition influences membrane function
      • Membrane lipids are precursors of important signaling compounds
      • Storage lipids are converted into carbohydrates in germinating seeds
        • Overview: Lipids to Sucrose
        • Lipase-Mediated Hydrolysis
        • β–Oxidation of Fatty Acids
        • The Glyoxylate Cycle
        • The Mitochondrial Role
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 14 Assimilation of Inorganic Nutrients
    • 14.1 Nitrogen in the Environment
      • Nitrogen passes through several forms in a biogeochemical cycle
      • Unassimilated ammonium or nitrate may be dangerous
    • 14.2 Nitrate Assimilation
      • Many factors regulate nitrate reductase
      • Nitrite reductase converts nitrite to ammonium
      • Both roots and shoots assimilate nitrate
      • Nitrate can be transported in both xylem and phloem
      • Transceptor contributes to nitrate signaling
    • 14.3 Ammonium Assimilation
      • Converting ammonium to amino acids requires two enzymes
      • Ammonium can be assimilated via an alternative pathway
      • Transamination reactions transfer nitrogen
      • Asparagine and glutamine link carbon and nitrogen metabolism
    • 14.4 Amino Acid Biosynthesis
    • 14.5 Biological Nitrogen Fixation
      • Free-living and symbiotic bacteria fix nitrogen
      • Nitrogen fixation requires microanaerobic or anaerobic conditions
      • Symbiotic nitrogen fixation occurs in specialized structures
      • Establishing symbiosis requires an exchange of signals
      • Nod factors produced by bacteria act as signals for symbiosis
      • Nodule formation involves phytohormones
      • The nitrogenase enzyme complex fixes N2
      • Amides and ureides are the transported forms of nitrogen
    • 14.6 Sulfur Assimilation
      • Sulfate is the form of sulfur transported into plants
      • Sulfate assimilation requires the reduction of sulfate to cysteine
        • Sulfate Activation
        • Incorporation of Sulfide into Cysteine
        • Phosphorylation of APS
      • Sulfate assimilation occurs mostly in leaves
      • Methionine is synthesized from cysteine
    • 14.7 Phosphate Assimilation
      • miRNAs contribute to phosphate and sulfate signaling
    • 14.8 Oxygen Assimilation
    • 14.9 The Energetics of Nutrient Assimilation
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 15 Abiotic Stress
    • 15.1 Defining Plant Stress
      • Physiological adjustment to abiotic stress involves trade-offs between vegetative and reproductive development
    • 15.2 Acclimation and Adaptation
      • Adaptation to stress involves genetic modification over many generations
      • Acclimation allows plants to respond to environmental fluctuations
    • 15.3 Environmental Factors and Their Biological Impacts on Plants
      • Water deficit decreases turgor pressure, increases ion toxicity, and inhibits photosynthesis
      • Temperature stress affects a broad spectrum of physiological processes
      • Flooding results in anaerobic stress to the root
      • Salinity stress has both osmotic and cytotoxic effects
      • During freezing stress, extracellular ice crystal formation causes cell dehydration
      • Heavy metals can both mimic essential mineral nutrients and generate ROS
      • Ozone and ultraviolet light generate ROS that cause lesions and induce PCD
      • Combinations of abiotic stresses can induce unique signaling and metabolic pathways
      • Interactions occur between abiotic and biotic stresses
      • Sequential exposure to different abiotic stresses sometimes confers cross-protection
      • Beneficial microbes can improve plant tolerance to abiotic stress
    • 15.4 Stress-Sensing Mechanisms in Plants
      • Early-acting stress sensors provide the initial signal for the stress response
    • 15.5 Signaling Pathways Activated in Response to Abiotic Stress
      • The signaling intermediates of many stress-response pathways can interact
      • Acclimation to stress involves transcriptional regulatory networks called regulons
      • Chloroplasts and mitochondria respond to abiotic stress by sending stress signals to the nucleus
      • Plant-wide waves of Ca2+ and ROS mediate systemic acquired acclimation
      • Epigenetic mechanisms, retrotransposons, and small RNAs provide additional protection against stress
      • Hormonal interactions regulate abiotic stress responses
    • 15.6 Physiological and Developmental Mechanisms That Protect Plants against Abiotic Stress
      • Plants adjust osmotically to drying soils by accumulating solutes
      • Submerged organs develop aerenchyma tissue in response to hypoxia
      • Antioxidants and ROS-scavenging pathways protect cells from oxidative stress
      • Molecular chaperones and molecular shields protect proteins and membranes during abiotic stress
      • Plants can alter their membrane lipids in response to temperature and other abiotic stresses
      • Exclusion and internal tolerance mechanisms allow plants to cope with toxic ions
      • Phytochelatins and other chelators contribute to internal tolerance of toxic metal ions
      • Plants use cryoprotectant molecules and antifreeze proteins to prevent ice crystal formation
      • ABA signaling during water stress causes the massive efflux of K+ and anions from guard cells
      • Plants can alter their morphology in response to abiotic stress
        • Leaf Area
        • Leaf Orientation
        • Trichomes
        • Cuticle
        • Root-to-Shoot Ratio
      • The process of recovery from stress can be dangerous to the plant and requires a coordinated adjustment of plant metabolism and physiology
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
• UNIT IV Growth and Development
  • 16 Signals from Sunlight
    • 16.1 Plant Photoreceptors
      • Photoresponses are driven by light quality or spectral properties of the energy absorbed
      • Plants responses to light can be distinguished by the amount of light required
    • 16.2 Phytochromes
      • Phytochrome is the primary photoreceptor for red and far-red light
      • Phytochrome can interconvert between Pr and Pfr forms
      • Pfr is the physiologically active form of phytochrome
      • The phytochrome chromophore and protein both undergo conformational changes in response to red light
      • Pfr is partitioned between the cytosol and the nucleus
    • 16.3 Phytochrome Responses
      • Phytochrome responses vary in lag time and escape time
      • Phytochrome responses fall into three main categories based on the amount of light required
        • Very Low Fluence Responses (VLFRS)
        • Low-Fluence Responses (LFRS)
        • High-Irradiance Responses (HIRS)
      • Phytochrome A mediates responses to continuous far-red light
      • Phytochrome B mediates responses to continuous red or white light
      • Roles for phytochromes C, D, and E are emerging
    • 16.4 Phytochrome Signaling Pathways
      • Phytochrome regulates membrane potentials and ion fluxes
      • Phytochrome regulates gene expression
      • Phytochrome interacting factors (PIFs) act early in signaling
      • Phytochrome signaling involves protein phosphorylation and dephosphorylation
      • Phytochrome-induced photomorphogenesis involves protein degradation
    • 16.5 Blue-Light Responses and Photoreceptors
      • Blue-light responses have characteristic kinetics and lag times
    • 16.6 Cryptochromes
      • The activated FAD chromophore of cryptochrome causes a conformational change in the protein
      • cry1 and cry2 have different developmental effects
      • Nuclear cryptochromes inhibit COP1-induced protein degradation
      • Cryptochrome can also bind to transcriptional regulators directly
    • 16.7 Interactions of Cryptochrome with Other Photoreceptors
      • Stem elongation is inhibited by both red and blue photoreceptors
      • Phytochrome interacts with cryptochrome to regulate flowering
      • The circadian clock is regulated by multiple aspects of light
    • 16.8 Phototropins
      • Blue light induces changes in FMN absorption maxima associated with conformation changes
      • The LOV2 domain is primarily responsible for kinase activation in response to blue light
      • Blue light induces a conformational change that “uncages” the kinase domain of phototropin and leads to autophosphorylation
      • Phototropins trigger plant movements that enhance light use
      • Blue light initiates stomatal opening via activation of the plasma membrane H+-ATPase
    • 16.9 Responses to Ultraviolet Radiation
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 17 Seed Dormancy, Germination, and Seedling Establishment
    • 17.1 Seed Structure
      • Seed anatomy varies widely among different plant groups
    • 17.2 Seed Dormancy
      • There are two basic types of seed dormancy mechanisms: exogenous and endogenous
      • Non-dormant seeds can exhibit vivipary and precocious germination
      • The ABA:GA ratio is the primary determinant of embryonic seed dormancy
    • 17.3 Release from Dormancy
      • Light is an important signal that breaks dormancy in small seeds
      • Some seeds require either chilling or after-ripening to break dormancy
      • Seed dormancy can be broken by various chemical compounds
    • 17.4 Seed Germination
      • Germination and postgermination can be divided into three phases corresponding to the phases of water uptake
    • 17.5 Mobilization of Stored Reserves
      • Cereal seeds are a model for understanding starch mobilization
      • Legume seeds are a model for understanding protein mobilization
      • Oilseeds are a model for understanding lipid remobilization
    • 17.6 Seedling Growth and Establishment
      • The development of emerging seedlings is strongly influenced by light
      • Gibberellins and brassinosteroids both suppress photomorphogenesis in darkness
      • Hook opening is regulated by phytochrome, auxin, and ethylene
      • Vascular differentiation begins during seedling emergence
      • The root tip has specialized cells
      • Ethylene and other hormones regulate root hair development
    • 17.7 Differential Growth Enables Successful Seedling Establishment
      • Ethylene affects microtubule orientation and induces lateral cell expansion
      • Auxin promotes growth in stems and coleoptiles, while inhibiting growth in roots
      • The minimum lag time for auxin-induced elongation is 10 minutes
      • Auxin-induced proton extrusion loosens the cell wall
    • 17.8 Tropisms: Growth in Response to Directional Stimuli
      • Gravitropism involves the lateral redistribution of auxin
      • The gravitropic stimulus perturbs the symmetric movements of auxin
      • Gravity perception is triggered by the sedimentation of amyloplasts
      • Gravity sensing may involve pH and calcium ions (Ca2+) as second messengers
      • Thigmotropism involves signaling by Ca2+, pH, and reactive oxygen species
      • Hydrotropism involves ABA signaling and asymmetric cytokinin responses
      • Phototropins are the light receptors involved in phototropism
      • Phototropism is mediated by the lateral redistribution of auxin
      • Shoot phototropism occurs in a series of steps
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 18 Vegetative Growth and Organogenesis: Primary Growth of the Plant Axis
    • 18.1 Meristematic Tissues: Foundations for Indeterminate Growth
      • The root and shoot apical meristems use similar strategies to enable indeterminate growth
    • 18.2 The Root Apical Meristem
      • The root tip has four developmental zones
      • The origin of different root tissues can be traced to specific initial cells
      • Auxin and cytokinin contribute to the maintenance and function of the RAM
    • 18.3 The Shoot Apical Meristem
      • The shoot apical meristem has distinct zones and layers
      • A combination of positive and negative interactions determines apical meristem size
      • KNOX class homeodomain transcription factors help maintain proliferation in the SAM through regulation of cytokinin and GA concentrations
      • Localized auxin accumulation promotes leaf initiation
      • Axillary meristems form in the axils of leaf primordia
    • 18.4 Leaf Development
      • Growth determines leaf shape
    • 18.5 The Establishment of Leaf Polarity
      • A signal from the SAM initiates adaxial–abaxial polarity
      • Antagonism between sets of transcription factors determines adaxial–abaxial leaf polarity
      • MYB transcription factors, HD-ZIP III proteins, and KNOX1 repression promote adaxial identity
      • Abaxial identity is determined by auxin, KANADI, and YABBY
      • Blade outgrowth is auxin dependent and regulated by the YABBY and WOX genes
      • Leaf proximal–distal polarity also depends on specific gene expression
      • In compound leaves, de-repression of the KNOX1 gene promotes leaflet formation
    • 18.6 Differentiation of Epidermal Cell Types
      • Guard cell identity is determined by a specialized epidermal lineage
      • Two groups of bHLH transcription factors govern stomatal cell identity transitions
      • Cell-to-cell peptide signals regulate stomatal patterning
      • Intrinsic polarity in the stomatal lineage aids stomatal spacing
      • Environmental factors also regulate stomatal density
      • Stomata development in monocots involves some genes that are orthologous to those in Arabidopsis
    • 18.7 Venation Patterns in Leaves
      • The primary leaf vein is initiated discontinuously from the preexisting vascular system
      • Auxin canalization initiates development of the leaf trace
      • Basipetal auxin transport from the L1 layer of the leaf primordium initiates development of the leaf trace procambium
      • The existing vasculature guides the growth of the leaf trace
      • Vascular development proceeds from procambium differentiation
      • Higher-order leaf veins differentiate in a predictable hierarchical order
      • Auxin regulates higher-order vein formation and patterning
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 19 Vegetative Growth and Organogenesis: Branching and Secondary Growth
    • 19.1 Shoot Branching and Architecture
      • Auxin, cytokinins, and strigolactones regulate axillary bud outgrowth
      • Auxin from the shoot tip maintains apical dominance
      • Strigolactones act locally to repress axillary bud growth
      • Cytokinins antagonize the effects of strigolactones
      • Integration of environmental and hormonal branching signals is required for plant fitness
      • Axillary bud dormancy is affected by season, position, and age factors
    • 19.2 Root Branching and Architecture
      • Lateral root primordia arise from the xylem pole pericycle cells
      • Lateral root formation can be divided into four distinct stages
      • Lateral root founder cells undergo asymmetric cell divisions to initiate formation of lateral root primordia
      • Monocots and eudicots differ in their predominant root types
      • Transcription factors regulate the gravitropic setpoint angles of lateral roots and shoots
      • Plants can modify their root system architecture to optimize water and nutrient uptake
    • 19.3 Secondary Growth
      • Two types of lateral meristems are involved in secondary growth
      • The vascular cambium produces secondary xylem and phloem
      • Mobile transcription factors pre-pattern the vascular cambium
      • The gene networks that control secondary meristems share similarities and differences with those that control the apical meristems
      • Several phytohormones regulate vascular cambium activity and differentiation of secondary xylem and phloem
      • The cork cambium gives rise to the outer corky layer called the periderm
      • Bark has diverse protective and storage functions
      • Epicormic buds covered by bark can sprout after forest fires
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 20 The Control of Flowering and Floral Development
    • 20.1 Floral Evocation: Integrating Environmental Cues
    • 20.2 The Shoot Apex and Phase Changes
      • Plants progress through three developmental phases
      • Juvenile tissues are produced first and are located at the base of the shoot
      • Phase changes can be influenced by nutrients, gibberellins, and other signals
    • 20.3 Circadian Rhythms: The Clock Within
      • Circadian rhythms exhibit characteristic features
      • Phase shifting adjusts circadian rhythms to different day–night cycles
      • Phytochromes and cryptochromes entrain the clock
    • 20.4 Photoperiodism: Monitoring Day Length
      • Plants can be classified according to their photoperiodic responses
      • The leaf is the site of perception of the photoperiodic signal
      • The length of the night is important for floral induction
      • Night breaks can cancel the effect of the dark period
      • Photoperiodic timekeeping during the night depends on a circadian clock
      • The external coincidence model is based on oscillating light sensitivity
      • The coincidence of CONSTANS expression and light promotes flowering in LDPs
      • SDPs use a coincidence mechanism to inhibit flowering in long days
      • Phytochrome is the primary photoreceptor in photoperiodism
      • A blue-light photoreceptor regulates flowering in some LDPs
    • 20.5 Long-Distance Signaling Involved in Flowering
      • Grafting studies provided the first evidence for a transmissible floral stimulus
      • Florigen is translocated in the phloem
    • 20.6 The Identification of Florigen
      • The Arabidopsis protein FLOWERING LOCUS T (FT) is florigen
    • 20.7 Vernalization: Promoting Flowering with Cold
      • Vernalization results in competence to flower at the shoot apical meristem
      • Vernalization can involve epigenetic changes in gene expression
      • A range of vernalization pathways may have evolved
    • 20.8 Multiple Pathways Involved in Flowering
      • Gibberellins and ethylene can induce flowering
      • The transition to flowering involves multiple factors and pathways
    • 20.9 Floral Meristems and Floral Organ Development
      • The shoot apical meristem in Arabidopsis changes with development
      • The four different types of floral organs are initiated as separate whorls
      • Two major categories of genes regulate floral development
      • Floral meristem identity genes regulate meristem function
      • Homeotic mutations led to the identification of floral organ identity genes
      • The ABC model partially explains the determination of floral organ identity
      • Arabidopsis Class E genes are required for the activities of the A, B, and C genes
      • According to the Quartet Model, floral organ identity is regulated by tetrameric complexes of the ABCE proteins
      • Class D genes are required for ovule formation
      • Floral asymmetry in flowers is regulated by gene expression
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 21 Sexual Reproduction: From Gametes to Fruits
    • 21.1 Development of the Male and Female Gametophyte Generations
    • 21.2 Formation of Male Gametophytes in the Stamen
      • Pollen grain formation occurs in two successive stages
      • The multilayered pollen cell wall is surprisingly complex
    • 21.3 Female Gametophyte Development in the Ovule
      • The Arabidopsis gynoecium is an important model system for studying ovule development
      • The vast majority of angiosperms exhibit Polygonum-type embryo sac development
      • Functional megaspores undergo a series of free nuclear mitotic divisions followed by cellularization
    • 21.4 Pollination and Fertilization in Flowering Plants
      • The progamic phase includes everything from pollen landing and tube growth to the fusion of sperm and egg
      • Adhesion and hydration of a pollen grain on a compatible flower depend on recognition between pollen and stigma surfaces
      • Ca2+-triggered polarization of the pollen grain precedes tube formation
      • Pollen tubes grow by tip growth
      • Receptor-like kinases are thought to regulate the ROP1 GTPase switch, a master regulator of tip growth
      • Pollen tube tip growth in the pistil is guided by both physical and chemical cues
      • Style tissue may condition pollen tubes to grow toward the embryo sac
      • Synergid cells release chemoattractants that guide pollen tube growth to the micropyle
      • Double fertilization occurs in three distinct stages
    • 21.5 Selfing versus Outcrossing
      • Hermaphroditic and monoecious species have evolved floral features to ensure outcrossing
      • Cytoplasmic male sterility (CMS) occurs in the wild and is of great utility in agriculture
      • Self-incompatibility (SI) is the primary mechanism that enforces outcrossing in angiosperms
      • Two distinct genetic mechanisms govern self-incompatibility
      • The Brassicaceae sporophytic SI system is mediated by S locus–encoded receptors and ligands
      • Cytotoxic S-RNases and F-box proteins determine gametophytic self-incompatibility (GSI)
    • 21.6 Apomixis: Asexual Reproduction by Seed
      • Apomixis is not an evolutionary dead end
    • 21.7 Endosperm Development
      • Cellularization of coenocytic endosperm in Arabidopsis progresses from the micropylar to the chalazal region
      • Cellularization of the coenocytic endosperm of cereals progresses centripetally
      • Endosperm development and embryogenesis can occur autonomously
      • Many of the genes that control endosperm development are differentially expressed maternal or paternal genes
      • Cells of the starchy endosperm and aleurone layer follow divergent developmental pathways
    • 21.8 Seed Coat Development
      • Seed coat development appears to be regulated by the endosperm
    • 21.9 Seed Maturation and Desiccation Tolerance
      • Seed filling and desiccation tolerance phases overlap in most species
      • The acquisition of desiccation tolerance involves many metabolic pathways
      • During the acquisition of desiccation tolerance, the cells of the embryo acquire a glassy state
      • LEA proteins and nonreducing sugars have been implicated in seed desiccation tolerance
      • Abscisic acid plays a key role in seed maturation
      • Coat-imposed dormancy is correlated with long-term seed viability
    • 21.10 Fruit Development and Ripening
      • The phytohormones auxin and gibberellic acid (GA) regulate fruit set and parthenocarpy
      • Specific transcription factors regulate the development of the dehiscence zone
      • Tomato is an important model system for studying fleshy fruit development
      • Fleshy fruits undergo ripening
      • Ripening involves changes in the color of fruit
      • Fruit softening involves the coordinated action of many cell wall–degrading enzymes
      • Taste and flavor reflect changes in acids, sugars, aroma, and other compounds
      • The causal link between ethylene and ripening was demonstrated in transgenic and mutant tomatoes
      • Climacteric and non-climacteric fruit differ in their ethylene responses
      • The ripening process is transcriptionally regulated
      • Studying the molecular mechanism of ripening can have commercial applications
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 22 Embryogenesis: The Origin of Plant Architecture
    • 22.1 Embryogenesis in Monocots and Eudicots
      • Embryogenesis differs between monocots and eudicots, but also shares common features
        • Maize Embryogenesis
        • Arabidopsis Embryogenesis
    • 22.2 Establishment of Apical–Basal Polarity
      • Apical–basal polarity is established early in embryogenesis
      • Zygote polarization can be studied using live imaging
    • 22.3 Mechanisms Guiding Embryogenesis
      • Intercellular signaling processes play key roles in guiding position-dependent development
      • Cell-cell communication during early embryo development may be regulated by plasmodesmata
      • Mutant analyses have identified genes for signaling processes that are essential for embryo organization
    • 22.4 Auxin Signaling During Embryogenesis
      • Spatial patterns of auxin accumulation regulate key developmental events
      • The GNOM protein establishes a polar distribution of PIN auxin efflux proteins
      • MONOPTEROS encodes a transcription factor that is activated by auxin
    • 22.5 Radial Patterning During Embryogenesis
      • Procambial precursors for the vascular stele lie at the center of the radial axis
      • The differentiation of cortical and endodermal cells involves the intercellular movement of a transcription factor
    • 22.6 Formation of the Root and Shoot Apical Meristems
      • Root formation involves MONOPTEROS and other auxin-regulated transcription factors
      • Shoot formation requires HD-ZIP III, SHOOT MERISTEMLESS, and WUSCHEL genes
      • Plants can initiate embryogenesis in multiple types of cells
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 23 Plant Senescence and Developmental Cell Death
    • 23.1 Programmed Cell Death
      • Distinct types of PCD occur in plants
      • Developmental PCD and pathogen-triggered PCD involve distinct processes
      • The autophagy pathway captures and degrades cellular constituents within lytic compartments
      • Autophagy plays a dual role in the regulation of plant PCD
      • Autophagy is required for nutrient recycling during plant senescence
    • 23.2 The Leaf Senescence Syndrome
      • Leaf senescence may be sequential, seasonal, or stress-induced
      • Leaves undergo massive structural and biochemical changes during leaf senescence
      • The autolysis of chloroplast proteins occurs in multiple compartments
      • The STAY-GREEN (SGR) protein is required for both LHCP II protein recycling and chlorophyll catabolism
    • 23.3 Regulation of Leaf Senescence: A Multi-Layered Network
      • Leaf senescence depends on the comprehensive regulation of pathways that respond to endogenous and environmental factors
        • Transcriptional Regulation
        • Chromatin-Mediated Regulation
        • Posttranscriptional Regulation
        • Translational Regulation
        • Posttranslational Regulation
        • Light Signaling
        • Circadian Rhythms
      • Plant hormones and other signaling agents can act as positive or negative regulators of leaf senescence
      • Positive senescence regulators
        • Ethylene
        • Abscisic Acid (ABA)
        • Methyl Jasmonate (MeJA)
        • Salicylic Acid (SA)
        • Reactive Oxygen Species
        • Sugars
      • Negative senescence regulators
        • Cytokinin
        • Auxin
    • 23.4 Abscission
      • Organ abscission is regulated by developmental and environmental cues
    • 23.5 Whole-Plant Senescence
      • Angiosperm life cycles may be annual, biennial, or perennial
      • Whole-plant senescence differs from aging in animals
      • The determinacy of shoot apical meristems is developmentally regulated
      • Nutrient redistribution may trigger senescence in monocarpic plants
      • The productivity of tall trees continues to increase right up to the onset of senescence
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
  • 24 Biotic Interactions
    • 24.1 Plant Interactions with Beneficial Microorganisms
      • Nod factors are recognized by the Nod factor receptor (NFR) in legumes
      • Arbuscular mycorrhizal associations and nitrogen-fixing symbioses involve related signaling pathways
      • Rhizobacteria can increase nutrient availability, stimulate root branching, and protect against pathogens
    • 24.2 Herbivore Interactions That Harm Plants
      • Mechanical barriers provide a first line of defense against insect pests and pathogens
      • Plant specialized metabolites can deter insect herbivores
      • Plants store constitutive toxic compounds in specialized structures
      • Plants often store defense chemicals as nontoxic water-soluble sugar conjugates in the vacuole
    • 24.3 Inducible Defense Responses to Insect Herbivores
      • Plants can recognize specific components of insect saliva
      • Ca2+ signaling and activation of the MAP kinase pathway are early events associated with insect herbivory
      • Jasmonate activates defense responses against insect herbivores
      • Jasmonate acts through a conserved ubiquitin ligase signaling mechanism
      • Hormonal interactions contribute to plant–insect herbivore interactions
      • JA initiates the production of defense proteins that inhibit herbivore digestion
      • Herbivore damage induces systemic defenses
      • Glutamate receptor-like (GLR) genes are required for long-distance electrical signaling during herbivory
      • Herbivore-induced volatiles can repel herbivores and attract natural enemies
      • Herbivore-induced volatiles can serve as long-distance signals between plants
      • Herbivore-induced volatiles can also act as systemic signals within a plant
      • Defense responses to herbivores and pathogens are regulated by circadian rhythms
      • Insects have evolved mechanisms to defeat plant defenses
    • 24.4 Plant Defenses against Pathogens
      • Microbial pathogens have evolved various strategies to invade host plants
      • Pathogens produce effector molecules that aid in the colonization of their plant host cells
      • Plants can detect pathogens through perception of pathogen-derived “danger signals”
      • R genes provide resistance to individual pathogens by recognizing strain-specific effectors
      • The hypersensitive response is a common defense against pathogens
      • A single encounter with a pathogen may increase resistance to future attacks
      • The main components of the salicylic acid signaling pathway have been identified
      • Phytoalexins with antimicrobial activity accumulate after pathogen attack
      • RNA interference plays a central role in antiviral immune responses in plants
      • Some plant parasitic nematodes form specific associations through the formation of distinct feeding structures
      • Plants compete with other plants by secreting allelopathic specialized metabolites into the soil
      • Some plants are parasites of other plants
    • Summary
    • Web Material
    • Suggested Reading
    • List of Key Terms
• Glossary
• Illustration Credits
  • Chapter 1
  • Chapter 2
  • Chapter 3
  • Chapter 4
  • Chapter 5
  • Chapter 6
  • Chapter 7
  • Chapter 8
  • Chapter 9
  • Chapter 10
  • Chapter 11
  • Chapter 12
  • Chapter 13
  • Chapter 14
  • Chapter 15
  • Chapter 16
  • Chapter 17
  • Chapter 18
  • Chapter 19
  • Chapter 20
  • Chapter 21
  • Chapter 22
  • Chapter 23
  • Chapter 24
• Index
• List of Illustrations
• List of Tables
• Images
  • 1 Plant and Cell Architecture
  • 2 Cell Walls: Structure, Formation, and Expansion
  • 3 Genome Structure and Gene Expression
  • 4 Signals and Signal Transduction
  • 5 Water and Plant Cells
  • 6 Water Balance of Plants
  • 7 Mineral Nutrition
  • 8 Solute Transport
  • 9 Photosynthesis: The Light Reactions
  • 10 Photosynthesis: The Carbon Reactions
  • 11 Photosynthesis: Physiological and Ecological Considerations
  • 12 Translocation in the Phloem
  • 13 Respiration and Lipid Metabolism
  • 14 Assimilation of Inorganic Nutrients
  • 15 Abiotic Stress
  • 16 Signals from Sunlight
  • 17 Seed Dormancy, Germination, and Seedling Establishment
  • 18 Vegetative Growth and Organogenesis: Primary Growth of the Plant Axis
  • 19 Vegetative Growth and Organogenesis: Branching and Secondary Growth
  • 20 The Control of Flowering and Floral Development
  • 21 Sexual Reproduction: From Gametes to Fruits
  • 22 Embryogenesis: The Origin of Plant Architecture
  • 23 Plant Senescence and Developmental Cell Death
  • 24 Biotic Interactions

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