Welcome to

- the Senescence Wiki

An interactive online resource for researchers on plant senescence

• To learn more about SenWiki, go to Origin and objectives of SenWiki.
• For a people-friendly introduction to senescence, there's an account written for non-specialists on Sid Thomas's website.
• To become a contributor to SenWiki, please register (button on the Login panel).
• For a brief guide to uploading and editing content, go to How to...
• To comment, make an enquiry or just say hello, please contact Sid or Suzy by email: hot@aber.ac.uk; sfs@aber.ac.uk.
• To search SenWiki (it searches the rest of Sid Thomas's website too) go here.
• Scroll down to see the Table of Contents.

The support of the Leverhulme Trust is gratefully acknowledged

At present the following sections have content of some kind. In no case is the topic complete and contributions or suggestions would be heartily welcomed.

• 1.1.1
• 1.5
• 2.1: 2.1.1; 2.1.2
• 2.2: 2.2.1; 2.2.2; 2.2.3; 2.2.4
• 2.3: 2.3.1; 2.3.2; 2.3.3; 2.3.4
• 3.1: 3.1.1
• 3.2: 3.2.1; 3.2.2
• 5.1: 5.1.1; 5.1.2
• 5.2: 5.2.4
• 6.1: 6.1.1; 6.1.2; 6.1.3
• 7.2: 7.2.1
• 7.3: 7.3.1; 7.3.2; 7.3.3; 7.3.4; 7.3.5 (1-7)
• 7.6: 7.6.6
• 8.2:
• 9.1:
• 9.2:
• 9.3: 9.3.2
• 9.6: 9.6.2; 9.6.3; 9.6.4
• 10.1:

Table of Contents

• 1 What senescence is and isn't
  • 1.1 Origin of the word
    • 1.1.1 Etymology
    • 1.1.2 Related words (senile, senior, senate etc)
  • 1.2 Other words with similar meanings to senescence
    • 1.2.1 Ag(e)ing
    • 1.2.2 Geronto...
    • 1.2.3 Necro-, thanato-, acheronto-...
  • 1.3 Lifespan
  • 1.4 Viability, dying and death
  • 1.5 The specialised meanings of senescence in plant science
• 2 Senescence-like processes across the plant, animal and microbial kingdoms
  • 2.1 Cell growth and viability
    • 2.1.1 Growth curves of microorganisms and cell cultures
    • 2.1.2 Senescence as a normal phase of cell lifespan
  • 2.2 Cell movement and localised senescence
    • 2.2.1 Cell migration in gastrulation
    • 2.2.2 Rigid cell wall means no cell movement in plant development
    • 2.2.3 Cell elimination in animal development
    • 2.2.4 Lysigeny and schizogeny in plant morphogenesis
  • 2.3 Senescence in the life-cycle
    • 2.3.1 In embryogenesis
    • 2.3.2 In maturation
    • 2.3.3 In reproduction
    • 2.3.4 In individuals, populations and communities
  • 2.4 Senescence in response to abiotic stress
    • 2.4.1 Stress and strain
    • 2.4.2 Optimality, sub- and supra-optimality, lethality
    • 2.4.3 Resilience, acclimation, adaptation
    • 2.4.4 Senescence within existing morphology
    • 2.4.5 Senescence and morphological reconfiguration
    • 2.4.6 Catastrophic senescence
  • 2.5 Senescence and biotic interactions
    • 2.5.1 Commensalism, symbiosis, parasitism, biotrophism, necrotrophism
    • 2.5.2 Cell-cell interactions
    • 2.5.3 Pathogenesis
    • 2.5.4 Signalling within and between organisms
    • 2.5.5 Allelopathy
• 3 Senescence of vegetative plant organs and tissues
  • 3.1 Axes
    • 3.1.1 Shoots
    • 3.1.2 Roots
  • 3.2 Laterals
    • 3.2.1 Leaves
    • 3.2.2 Buds
    • 3.2.3 Branches
• 4 Senescence of reproductive plant organs and tissues
  • 4.1 Floral parts
  • 4.2 Gametes
  • 4.3 Embryos
  • 4.4 Fruits and seeds
• 5 Senescence of plant cells and organelles
  • 5.1 Cell types
    • 5.1.1 Green cells
    • 5.1.2 Highly coloured cells
    • 5.1.3 Non-pigmented cells
    • 5.1.4 Cells of structural tissue
    • 5.1.5 Reproductive cells
  • 5.2 Organelles
    • 5.2.1 Plastids
    • 5.2.2 Mitochondria
    • 5.2.3 Peroxi- and glyoxy-somes
    • 5.2.4 Vacuoles
    • 5.2.5 Nuclei
    • 5.2.6 Endomembrane system
    • 5.2.7 Cell walls
• 6 Biochemistry of plant senescence
  • 6.1 Pigment metabolism
    • 6.1.1 Chlorophyll
    • 6.1.2 Carotenoids
    • 6.1.3 Phenylpropanoids
    • 6.1.4 Others
  • 6.2 Macromolecule breakdown and salvage of nutrients
    • 6.2.1 Proteins
    • 6.2.2 Nucleic acids
    • 6.2.3 NPS metabolism
  • 6.3 Energy and oxidative metabolism
    • 6.3.1 Photosynthesis
    • 6.3.2 Respiration
    • 6.3.3 Lipid and carbohydrate catabolism
    • 6.3.4 Gluconeogenesis
    • 6.3.5 Redox metabolism
• 7 Molecular regulation of senescence
  • 7.1 Natural genetic variation in senescence
  • 7.2 Mutations
    • 7.2.1 Rapidly senescing types
    • 7.2.2 Stay-greens
      • 7.2.2.1 Cosmetic
      • 7.2.2.2 Functional
    • 7.2.3 Lesion mimic mutants
    • 7.2.4 Ripening mutants
  • 7.3 Genetic mapping of senescence traits
    • 7.3.1 Individual genes
    • 7.3.2 QTL
    • 7.3.3 Mapping is sensitive to remote developmental events
    • 7.3.4 Mapping is sensitive to the environment
    • 7.3.5 Examples of gene mapping in crop species
      • 7.3.5.1 Rice
      • 7.3.5.2 Sorghum
      • 7.3.5.3 Pearl Millet
      • 7.3.5.4 Maize
      • 7.3.5.5 Wheat
      • 7.3.5.6 Barley
      • 7.3.5.7 Other Species
  • 7.4 Senescence-associated genes
    • 7.4.1 Methods of isolation
    • 7.4.2 Classes of SAGs
  • 7.5 Molecular genetics and genomics of senescence
    • 7.5.1 Omics studies
    • 7.5.2 Bioinformatics resources
    • 7.5.3 Systems Biology approaches
  • 7.6 Genetic programming of senescence
    • 7.6.1 Transcription factors
    • 7.6.2 Regulation at the post-transcriptional level and at translation
    • 7.6.3 Protein processing and cell trafficking
    • 7.6.4 Metabolism-level control
    • 7.6.5 Epigenetics
    • 7.6.6 Programs and timetables
  • 7.7 Hormonal and other chemical regulators of senescence
    • 7.7.1 Cytokinins as senescence antagonists
    • 7.7.2 Ethylene as a promoter of senescence
    • 7.7.3 Salicyclic acid as a key component of signalling pathways
    • 7.7.4 Abscisic acid and gibberellins in regulatory
    • 7.7.5 Roles for jasmonates, nitrous oxide and other factors
  • 7.8 Modification of senescence
    • 7.8.1 Conventional breeding
    • 7.8.2 Molecular breeding
    • 7.8.3 Introgression
    • 7.8.4 Mutation breeding
    • 7.8.5 Transgenics
• 8 Senescence in relation to other terminal processes
  • 8.1 Hypersensitive response
    • 8.1.1 Cell death in response to attack by pathogens
    • 8.1.2 Autophagy
    • 8.1.3 Hypersensitivity in lesion-mimics
    • 8.1.4 The role of reactive oxygen
    • 8.1.5 Functional interplay between mitochondria and plastids
  • 8.2 Programmed cell death
    • 8.2.1 Antagonism between programmed cell death and senescence
    • 8.2.2 Plant apoptosis - is there such a thing or not?
  • 8.3 Seed germination
    • 8.3.1 Common programs and mechanisms
    • 8.3.2 The aleurone system
    • 8.3.3 Death of starchy endosperm
    • 8.3.4 Nutrient remobilisation and gluconeogenesis
  • 8.4 Reproduction
  • 8.5 Fruit ripening
  • 8.6 Acherontology
    • 8.6.1 The physiology and chemistry of dying and death
    • 8.6.2 Pseudosenescence
    • 8.6.3 Post-mortem changes
    • 8.6.4 "Genetics" of dying, death and the post-mortem phase
    • 8.6.5 Allelopathy
• 9 Senescence in ecology and evolution
  • 9.1 Acclimation and adaptation
    • 9.1.1 Tactical senescence
    • 9.1.2 Strategic senescence
    • 9.1.3 Interactions with other organisms
  • 9.2 Life-forms
    • 9.2.1 Raunkiaer classification
    • 9.2.2 Senescence patterns
  • 9.3 Life-cycle
    • 9.3.1 Perenniality
    • 9.3.2 Do plants age?
  • 9.4 Fitness
    • 9.4.1 Measures of fitness
    • 9.4.2 Materials and energy budgets
    • 9.4.3 What is the physiology of failing fitness?
  • 9.5 Turnover of individuals, populations, communities, floras
    • 9.5.1 Scaling of processes
    • 9.5.2 Emerging and vanishing properties
    • 9.5.3 Measurement of turnover dynamics
  • 9.6 Senescence in plant evolution
    • 9.6.1 Senescence-like processes in non-angiosperms
    • 9.6.2 Senescence in cryptogams
    • 9.6.3 Angiosperm evolution
    • 9.6.4 Invitation and warning signals to animals
• 10 Senescence and agriculture
  • 10.1 Senescence characteristics of crops
  • 10.2 Agronomy and management
    • 10.2.1 Crop husbandry for controlling senescence
    • 10.2.2 Monitoring senescence in the field
    • 10.2.3 What happens when things go wrong
  • 10.3 Senescence and yield
    • 10.3.1 Of cereal grain crops
    • 10.3.2 Of legumes
    • 10.3.3 Of green vegetables
    • 10.3.4 Of root vegetables
    • 10.3.5 Of fibre and timber species
    • 10.3.6 Of forages
    • 10.3.7 Of energy crops
    • 10.3.8 Of sources of pharmaceuticals, renewable raw materials and other phytochemicals
  • 10.4 Post-harvest biology
  • 10.5 Inputs and environmental impacts
    • 10.5.1 Irrigation, fertiliser, pesticides
    • 10.5.2 Costs and benefits of keeping plants alive longer
    • 10.5.3 Sustainability
    • 10.5.4 Economics
• 11 Senescence, culture and society
  • 11.1 Evolution of primate visual system
    • 11.1.1 The trichromatic system
    • 11.1.2 Plants and spectral tuning in Old World apes
    • 11.1.3 Molecular genetics of colour vision
    • 11.1.4 Colour sensitivity, perception and blindness
  • 11.2 Plants, colour and language
  • 11.3 Psychological and pathological relationships between people and plants
    • 11.3.1 The need for green spaces
    • 11.3.2 Gardens and parks
    • 11.3.3 Sports surfaces
    • 11.3.4 Consumer perceptions of food colour
  • 11.4 Senescence as a trope for the human condition
    • 11.4.1 Senescence in myth and legend
    • 11.4.2 The Pathetic Fallacy
    • 11.4.3 Senescence in literature and the visual arts
    • 11.4.4 Musical evocations of senescence
  • 11.5 The "Green Movement"
• 12 Notes
  • 12.1 QTLplural
• 13 Jargon Buster
  • 13.1 Allelic Variation
  • 13.2 Chlorophyll definition
  • 13.3 Chromosome
  • 13.4 DNA Markers
  • 13.5 Endopeptidase
  • 13.6 Genetic Map
  • 13.7 Genome
  • 13.8 Loci
  • 13.9 Meiosis
  • 13.10 Mendelian
  • 13.11 Mutations definition
  • 13.12 Phenotypic
  • 13.13 Polygenes
  • 13.14 Quantitative Trait Loci
  • 13.15 Rubisco
  • 13.16 SAG
  • 13.17 Segregating Population
  • 13.18 Post-mitotic
  • 13.19 Relative growth rate
• 14 How to...
• 15 Origin and objectives of SenWiki