introduction to botany. lecture 6 - a. shipunov...other tissues anatomy of stem introduction to...
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Other tissuesAnatomy of stem
Introduction to Botany. Lecture 6
Alexey Shipunov
Minot State University
September 8th, 2010
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Outline
1 Other tissuesPoikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
2 Anatomy of stemFrom SAM to primary structureVascular bundles
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Outline
1 Other tissuesPoikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
2 Anatomy of stemFrom SAM to primary structureVascular bundles
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Poikilo- and homoiohydricity
Poikilohydric plants do not save water, they survive evencomplete desiccationHomoiohydric plants save water, they always have similarwater content and do not survive after desiccationCompare with poikilo- and homoiothermic animals (reptilesvs. mammals)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Origins of poikilo- and homoiohydricityLife on the air and under the sun
drying**TTTTTTTTTTTTTTTTT
Epidermiswith cuticle
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transpiration''OOOOOOOO
Stomata��
water absobtion����
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Absorbingtissues
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Mycorhiza����
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Vasculartissues
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Homoiohydricity��
Anabiosiswwooooooooooo
Poikilohydricity��
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Increasing of biomassttjjjjjjjjjjjjjjjjj
competition��
3D growth��
increasingof weight
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Supporttissues
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further increasingof weight
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Lignin��?
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Cambium����
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Bigheight
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Rootsystem//
separation fromgametophyte
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Seed��
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ED
@A//
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Absorption tissues
Always primary, simple tissuesRhizoderm, or root hairs, originates from protoderm, butlife span is much shorter than of epidermisVelamen, originates from root cortex
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Rhizoderm
Root hairs of grass seedlings (LM)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Velamen
Outer cylinder is a velamen tissue of orchid root (LM, c© D.Webb)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Secretory tissues
Primary, simple or complex tissuesSpreading across plant body, concentrating in leaves andyoung stemsMay secrete latex, volatile oils, mucus and other chemicalsFunctions vary: attraction or dis-attraction, communication,defense etc.
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Laticifers
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Additional meristems
Intercalary meristems: locate in stems, regulates stemelongationMarginal meristems are leaf-specific, they regulate shapesRepair meristems help to cure wounds, they form budsand roots in unusual places
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
Poikilo- and homoiohydricityAbsorption tissuesSecretory tissuesAdditional meristems
Classification of tissues
Classification table: discussion
Tissues Primary SecondarySimple ... ...
Complex ... ...
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Protoderm to epidermis
Stem apex meristem (SAM) produces protodermProtoderm cells differentiate into epidermal cells
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Ground meristem to cortex and pith
SAM produces also ground meristemGround meristem differentiates into cortex and pithProcambium raises between cortex and pith, it formsvascular bundles or vascular cylinder
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Three primary meristems: procambium, protodermand ground meristem
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Young stem with primary tissues
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Older stem with hollow in the center
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Primary structure of stem
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Procambium to xylem and phloem
Outer layers of procambium form primary phloemInner layers become primary xylemSometimes outermost layers of procambium formpericycle (parenchyma cells)In some cases, inner layers of cortex could formendoderm
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Vascular bundle 1
Corn (Zea mays) mature stem cross-section showing singlevascular bundle, Brightfield (LM ×400)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Vascular bundle 2
Wild Sunflower (Helianthus sp.) with nearly mature vascularbundle (LM ×35)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Origin of vascular bundles
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Vascular bundles
Vascular bundles connect leaves and stemsIn many plants, they form ring on the cross-section of stem(“dicot” stem)Monocot stems usually have dispersed vascular bundles
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Vascular bundles and leaf traces
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Monocot stem
Corn (Zea mays) stem (LM ×4)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Primary Thickening Meristem (PTM)
PTM occurs only in “dicot” stems
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Steles 1
Stele is an overall configuration of primary vascular systemof plant stemThe most important kinds of steles are: protostele,siphonostele, eustele and ataktostele*
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Steles 2
(1) is protostele, (7) siphonostele (occurs in ferns), (8) eustele(“dicot” stem), (9) ataktostele (monocot stem)
Shipunov BIOL 154.6
Other tissuesAnatomy of stem
From SAM to primary structureVascular bundles
Summary
Absorbtion tissues take water from soilSecretory tissues extract different chemicals outsideSAM produces protoderm and ground meristem, groundmeristem differentiates into cortex and pithProcambium forms vascular bundles or vascular cylinderOuter layers of procambium transform into primaryphloem, inner layers — into primary xylemMonocot stem usually has dispersed vascular bundles(ataktostele)
Shipunov BIOL 154.6
Appendix For Further Reading
For Further Reading
Th. L. Rost, M. G. Barbour, C. R. Stocking, T. M. Murphy.Plant Biology. 2nd edition.Thomson Brooks/Cole, 2006.Chapters 4.3, 5.2 and 5.3.
Shipunov BIOL 154.6