Ebook: Plant Aging: Basic and Applied Approaches

For many, the terms aging, maturation and senescence are synonymous and used interchangeably, but they should not be. Whereas senescence represents an endogenously controlled degenerative programme leading to plant or organ death, genetiC aging encompasses a wide array of passive degenerative genetiC processes driven primarily by exogenous factors (Leopold, 1975). Aging is therefore considered a consequence of genetiC lesions that accumulate over time, but by themselves do not necessarily cause death. These lesions are probably made more severe by the increase in size and complexity in trees and their attendant physiology. Thus while the withering of flower petals following pollination can be considered senescence, the loss of viability of stored seeds more clearly represents aging (Norden, 1988). The very recent book "Senescence and Aging in Plants" does not discuss trees, the most dominant group of plants on the earth. Yet both angiospermic and gymnospermic trees also undergo the above phenomena but less is known about them. Do woody plants senesce or do they just age? What is phase change? Is this synonymous with maturation? While it is now becoming recognized that there is no programmed senescence in trees, senescence of their parts, even in gymnosperms (e. g. , needles of temperate conifers las t an average of 3. 5 years), is common; but aging is a readily acknowledged phenomenon. In theory, at least, in the absence of any programmed senescence trees should -live forever, but in practice they do not.

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Content:
Front Matter....Pages N1-xi
Front Matter....Pages 1-1
Aging of Meristems and Morphogenetic Potentialities....Pages 3-10
Maturation and Senescence: Types of Aging....Pages 11-17
Adult vs. Juvenile Explants: Directed Totipotency....Pages 19-25
Recovery of Transient Juvenile Capacities During Micropropagation of Filbert....Pages 27-36
Juvenility and Maturity of Woody Species in New Zealand....Pages 37-42
Development of Rejuvenation Methods for in Vitro Establishment, Multiplication and Rooting of Mature Trees....Pages 43-49
Aging in Tree Species: Present Knowledge....Pages 51-63
Front Matter....Pages 65-65
Special Problems and Prospects in the Propagation of Woody Species....Pages 67-74
Factors Affecting Tissue Culture Success in Mass Propagation....Pages 75-80
Effective Handling of Plant Tissue Culture....Pages 81-87
Plant Cells and Protoplast Immobilization as Tools for Studies on Cell Function, Metabolism and Differentiation....Pages 89-95
Recovery of Somatic Variation in Resistance of Populus to Septoria Musiva....Pages 97-112
Shoot-Tip Grafting in Vitro of Woody Species and Its Influence on Plant Age....Pages 113-116
The Control by Cryopreservation of Age-Related Changes in Plant Tissue Cultures....Pages 117-123
Vitrification in Plant Tissue Culture....Pages 125-131
Front Matter....Pages 133-137
The Molecular Genetics of Maturation in Eastern Larch (Larix Laricina [Du Roi] K. Koch)....Pages 139-139
Cellular, Biochemical and Molecular Characteristics Related To Maturation and Rejuvenation In Woody Species....Pages 141-145
Uptake Characteristics of Sugars and Amino Acids by Vitis vinifera L. Protoplasts....Pages 147-152
Improvement of Micropropagation Methods Linked To Biochemical Properties During “In Vitro” Cultures....Pages 153-159
Front Matter....Pages 161-168
Age Dependence of Different Components of Variance....Pages 139-139
Interactions Between Genotype and Developmental Factors Modifying Peroxidase Expression....Pages 169-181
Organogenesis: Structural, Physiological and Biochemical Aspects....Pages 183-190
Changes in Carbohydrate Metabolism During Transient Senescence of Mustard (Sinapis Alba L.) Cotyledons....Pages 191-197
Study of Gene Expression During in Vitro Culture of Tobacco thin Cell Layers by two-Dimensional Electrophoresis of Proteins....Pages 199-205
An Experimental Model for the Analysis of Plant/Cell Differentiation: Thin Cell Layer Concept, Strategy, Methods, Records and Potential....Pages 207-213
Nutrient Remobilization, Nitrogen Metabolism and Chloroplast Gene Expression in Senescent Leaves....Pages 215-224
Oxidative Stress and Senescence in Oat Leaves....Pages 225-229
Structure and Function of Glutamate Dehydrogenase During Transient Senescence of Mustard (Sinapis Alba L.) Cotyledons....Pages 231-237
Front Matter....Pages 239-245
Effects of Vascular Tissue Containing a Meristem on Adjacent Pith: Hormone-Like Factors....Pages 247-247
Hormonal Control of Senescence....Pages 249-256
Modulation, Purification and Function of a Soluble Auxin Receptor....Pages 257-262
Free Radicals in Stressed and Aging Plant Tissue Cultures....Pages 263-267
Hormone Action and Sensitivity: Possible Relation to Aging....Pages 269-275
Front Matter....Pages 277-284
Cellular and Morphogenic Reorientation Induced by Inserting Foreign DNA....Pages 285-292
Genetic Manipulation of Forest Trees: Implications for Physiological Processes....Pages 293-293
Biotechnology in Forest Tree Improvement: Trees of the Future....Pages 295-301
Biotechnology in Forest Tree Improvement: Trees of the Future....Pages 303-309
Front Matter....Pages 311-318
Micropropagation of Vitis Vinifera from “Vinho Verde” Region of Portugal: A Method for Grapevine Leafroll Virus Elimination....Pages 319-324
Front Matter....Pages 325-325
In Vitro Culture of Pistacia Vera L. Embryos and Aged Trees Explants....Pages 327-334
Tissues Culture and Regeneration in Jojoba....Pages 325-325
Effect of Cold Temperature on Shoot Regeneration in Vitro from Aged Cultures of GF-677 (Prunus Persica ? Prunus Amygdalus)....Pages 335-338
Age and Meristem “in Vitro” Culture Behaviour in Filbert....Pages 339-343
Influence of Explant Source on in Vitro Axillary Shoot Formation in Oak (Quercus robur L.) Seedlings....Pages 345-349
Segmentation Effect of Immature Spike on Triticale Calli Induction....Pages 351-355
Cuticle Development in Dianthus Caryophyllus Plantlets....Pages 357-360
Partial “Rejuvenation” of 20-Year-Old Sitka Spruce by Lower Crown Pruning....Pages 361-365
Rejuvenation of Adult Specimens of Castanea Sativa Mill: Through In Vitro Micropropagation....Pages 367-371
Embryogenic Cultures of Tobacco Pollen as a Model System to Study Plant Rejuvenation....Pages 373-376
The Meristematic Calli of Maize: A Maintenance System of Tissue Juvenility....Pages 377-382
Growth and Development in in Vitro Long Term Cultures....Pages 383-387
Protein Patterns on Corylus Avellana L Rooting Capacity....Pages 389-393
Inducing Artificial Tetraploids from Diploid Meadow Fescue (Festuca Pratensis Huds.) Varieties and the Investigation of Some Meiotic Characteristics of Them....Pages 395-398
Inactivation of Peroxidase: Its Role in Plant Senescence....Pages 399-403
Electron Microscope Observations and BA Effects in Apple Cells....Pages 405-410
Polyamine and Ethylene Metabolisms During Tomato Fruit Ripening....Pages 411-415
Levels of Cytokinins in Aging and Rejuvenated Corylus avellanaL. Tissues....Pages 417-421
Changes in Polyamines Related with Pruning as a Method for Rejuvenation in Filbert....Pages 423-428
Front Matter....Pages 429-433
Early Flowering in Seedlings of Asparagus Promoted by Diuron and Atrazine....Pages 435-438
Epilogue....Pages 439-443
Back Matter....Pages 325-325
....Pages 445-447