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Plant Physiology by Lincoln Taiz and Eduardo Zeiger
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WHAT IS PHYSIOLOGY?
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Physiology focus on: How organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system
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PLANT PHYSIOLOGY Closely related fields include: 1.plant morphology (structure of plants), 2.plant ecology (interactions with the environment) 3.phytochemistry (biochemistry of plants), 4.cell biology, 5.genetics, 6.biophysics 7.molecular biology.
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What kind of unique bioprocesses do plants have? Photosynthesis, Respiration, Plant nutrition, Plant hormone functions, Tropisms, (in latin, tropos, a turning) Nastic movements, movements are non-directional responses to stimuli (e.g. temperature, light irradiance), Photoperiodism, physiological reaction of organisms to the length of day or night Photomorphogenesis,
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Circadian rhythms, Environmental stress physiology, Seed germination, Dormancy and stomata function and transpiration, Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped Plant water relations What kind of unique bioprocesses do plants have?
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Plants Plants range in size from less than 1 cm tall to greater than 100 m
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duckweed (Lemna) 1 cm tall
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Giant Saguaro Cactus Surprise SaguarosSurprise Saguaros, besaball team 20 meters Located in Arizona, California, Sonoran Desert Edible fruits
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spines are sometimes used as sewing needles
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Redwood Tree Servi ağacı http://www.youtube.com/watch?v=C9LHjV48e9s Helios - 114,58 meter Location: Redwood Creek, California, ABD
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Modern Plant Physiology: A highly interdisciplinary field Physiology Biochemistry Genetics Molecular Biology Biotechnology Structural Biology Developmental Biology
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What is Plant?
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Why Study Plants? B. Fibers-- 1. Cotton: 2. Paper: Average paper 3. Fibers such as nylon and rayon are processed from wood fibers.
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Why Study Plants? III.Other molecules A. Medicines Also noteworthy are aspirin, ephedra (banned), quinine, ginkgolides, and others. Rosy periwinkle from Madagascar treats two cancers: juvenile leukemia and Hodgkin’s disease. Threatened by increasing population. Taxol from the bark of the pacific yew tree ( Taxus bacata ) is one of the most promising anti-cancer drugs. Foxglove ( Digitalis lanata ) produces digitoxin, which treats heart disease ( congestive heart failure ).
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Why Study Plants? B. Spices C. Oils D. Essential amino acids--There are 8 amino acids that we need in our cells, but we don’t have the ability to produce them ourselves. We can most easily get them from plants. To get the complete set of essential amino acids, a combination of legumes and cereals is best. E. Fossil fuels like coal, crude oil, and natural gas are the products of plants that died a long time ago.
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Some “hot” areas in plant and nutrient research Improving plant water-use efficiency Improving salt tolerance Improving nutritional value of plants (e.g., golden rice, increasing Fe content) Phytoremediation
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An Overview to Plant Structure
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Bryophytes Small (rarely more than 4 cm in height), very simple land plants, and the least abundant in terms of number of species and overall population. Bryophytes include mosses, These small plants have life cycles that depend on water during the sexual phase. Water facilitates fertilization, the fusion of gametes to produce a diploid zygote, Bryophytes are like algae in other respects as well: They have neither true roots nor true leaves, they lack a vascular system, and they produce no hard tissues for structural support. The absence of these structures that are important for growth on land greatly restricts the potential size of bryophytes, which, unlike algae, are terrestrial rather than aquatic.
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MarchantiaMarchantia, a liverwort, koyun otu
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Mosses, karayosunu
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Hornworts (boynuz otu) are the third group of bryophytes
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Ferns Represent the largest group of spore-bearing vascular plants. In contrast to the bryophytes, ferns have true roots, leaves, and vascular tissues, and they produce hard tissues for support. These architectural features enable ferns to grow to the size of small trees. Although ferns are better adapted to the drying conditions of terrestrial life than bryophytes are, They still depend on water as a medium for reproduction. This dependence on water during a critical stage of their life cycle restricts the ecological range of ferns to relatively moist habitats.
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Seed plants have been able to adapt to an extraordinary range of habitats. The embryo, protected and nourished inside the seed, is able to survive in a dormant state during unfavorable growing conditions such as drought. Seed dispersal also facilitates the dissemination of the embryos away from the parent plant. Another important feature of seed plants is their mode of fertilization. Fertilization in seed plants is brought about by wind- or insect-mediated transfer of pollen, the gamete- producing structure of the male, the stamen, The Seed Plants
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The most successful terrestrial plants. Seed Plants need to produce seeds: WHY they need to do it? The Seed Plants
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There are two categories of seed plants: Gymnosperms (from the Greek for "naked seed") Angiosperms (based on the Greek for "vessel seed," or seeds contained in a vessel). Gymnosperms; About 700 species are known. The largest group of gymnosperms is the conifers ("cone-bearers"), which include such commercially important forest trees as pine, fir, spruce, and redwood. Two types of cones are present: male cones, which produce pollen, female cones, which bear ovules. The ovules are located on the surfaces of specialized structures called cone scales.. The Seed Plants CYCAD-Ceratozamia mexicana
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New Jersey’s native Pitch Pine, for example, will remain closed on the tree for years until exposed to temperatures over 130 o F. The strategy here is that the tree will not release seeds until after a forest fire has burned the twig and leaf debris from the forest floor, making the site suitable for seedling germination and growth.
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Angiosperms (based on the Greek for "vessel seed," or seeds contained in a vessel). Angiosperms; Today, they dominate the landscape and about 250,000 species are known, but many more remain to be characterized. The major innovation of the angiosperms is the flower; hence they are referred to as flowering plants. Angiosperms are divided into two major groups, Dicotyledons (dicots) Monocotyledons (monocots) This distinction is based primarily on the number of cotyledons, or seed leaves. In addition, the two groups differ with respect to other anatomical features, such as the arrangement of their vascular tissues, and their floral structure.
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Review of plant anatomy Leaves Vascular tissues Cuticle Mesophyll layer Stomates and guard cells Stems Vascular bundle Roots Lateral roots Taproots Root hairs
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Meristem Localised developmental cells – Apical meristems 1.Stem tips (longitudinal development-elongation- up) 2.Root tips (longitudinal development-elongation- down) 3.Nodium (formation of branches) – Lateral Meristem 1.Vascular cambium 2.Bark cambium – Pericyle (In root-inner meristematic layer)
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Tissues in Plant A) Dermal tissues; – Epidermis B) Ground tissue – Paranchyma-photosyntesis – Collenchyma-support-primary development-alive – Sclerenchyma-support-secondary development-death Sclereids Fibers C) Vascular tissues – Ploem – Xylem
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Cross section of root Vascular bundle (Stele) = contains xylem and phloem Cortex Epidermis Root hairs – Absorb water and minerals
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Stems support leaves to maximize light absorption part of conduit for transport of water, minerals, and organic solutes storage
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Cytokinesis in animal and plant cells
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Fig. 7.1
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Fig. 7.22
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Plant vs. animal cells Plant – Cell wall – Plastids – Tonoplast – Divide by inserting wall – Plasmodesmata – Ergastic deposits common – Modular construction – Stem cells common – Totipotent cells common Animal – No cell wall – No plastids – No tonoplast (lysomes instead) – Divide by pinching – Gap junctions – Deposits rare – Non-modular – Stem cells rare – No totipotency
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