Lecture PBPM - Secondary plant cell wall

Secondary plant cell wallSecondary plant cell wall

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Lecture PBPM - Secondary plant cell wall: topics

Topics

plant/environment interface of cutin (lipophilic biopolymer)plant/environment interface of cutin (lipophilic biopolymer)fine structure of leaf surfaces

chemical composition of cutin and waxlipid and wax biosynthesislipid and wax biosynthesis

cuticle structure

l / i i f f b i (li hili bi l )plant/environment interface of suberin (lipophilic biopolymer)chemical composition of suberin

biosynthesis of suberinoccurrence and fine structure of suberized cell walls

lignin as an aromatic biopolymer: mechanical stability of plantsg p y y plignin monomers and lignin biosynthesis

lignin polymerisationlignin structure

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lignin structurehistochemical detection of lignin

lignification and pathogen defence

Lecture PBPM - Fine structure of leaf surfaces covered by cuticles

Caltha palustris Anthemis tinctoria Viola tricolor

P th i t i id t N t i b i li d iC l h l i

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Parthenocissus tricuspidata Neoporteria brevicylindricaCaltha palustris

Lecture PBPM - Fine structure of leaf surfaces covered by waxes

Taxus baccata Hypericum buckleyiLonicera tatarica

Heliconia collinsiana Lecythis chartacea Williamodendron quadrilocelathum

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Lecture PBPM - Wax covered stomate

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Lecture PBPM - Wax mutants of Arabidosis thaliana help to identifying wax biosynthesis genes

stemwt cer7 cer 17

siliquewt cer7 cer 17

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Lecture PBPM - Cuticle of Clivia nobilis in the light microscope

cell wall staining cutin staining cell wall andcutin stainingg

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Lecture PBPM - Cuticle in the transmission electron microscope: glandular cell of Lamium

cuticle

cell wall

cellcell

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Lecture PBPM - Relative distribution of lipids in leaves

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Lecture PBPM - Proposed pathway for wax biosynthesis

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Lecture PBPM - Major constituents of cutin and wax

ω-hydroxyfatty acids h i l th fω hydroxyfatty acids

in chain-hydroxyfatty acids

chain lengths ofC16 and C18

waxes can have chain lengthsbetween C22 to C60

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Lecture PBPM - Proposed poylmer structure of cutin

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Lecture PBPM - Epidermis covered by a cuticle

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Lecture PBPM - Suberized interfaces of plants

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Lecture PBPM - Suberin and lenticells

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Lecture PBPM - Suberin biosynthesis

nH3C

C O O H

OH

n

H3COH

CR

O

C C S C oA

OH

H

CR

O

S C o A

H3CC O O H

OHn

P450?FARP450

FAE

KCS(FDH, HIC, KCS1 ?)

n

H3CC O O H

CR C C S C oA

OH H

CR

O H

C C S C o A

OH

HH

C24C22C20C18

FAD

P450

n

H3CC O O H

CR C C S C oA

HH

CR C C S C oA

O

HHP450(LCR, ATT1 ?)

HOn

C O O H

P450 ω-hydroxyacid dehydrogenase(HTH ?)

On

C O O H

ω-oxo-acid dehydrogenase

• elongation – FAE (KCS)

• functionalisation – P450

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nC O O HO

OH

Lecture PBPM - Major constituents of suberin

ω hydroxyfatty acids of various chain lengthsω-hydroxyfatty acids of various chain lengths

α,ω-diacids of various chain lengths

chain lengths can vary between C16 to C32

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Lecture PBPM - Stem periderm of Malus sylvestris

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Lecture PBPM - Belowground suberized interfaces of plants in roots

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Lecture PBPM - Suberin ultra structure of potato periderm (Solanum tuberosum)

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Lecture PBPM - Lignified cell walls of Asparagus officinalis in the light microscope

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Lecture PBPM - Histochemical detection of lignin

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Lecture PBPM - Biosynthesis of phenolics leading to lignin monomers: easy scheme

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Lecture PBPM - Biosynthesis of phenolics leading to lignin monomers: detailed scheme

p-Coumaryl alcohol

Coniferyl alcohol

Sinapyl alcohol

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Sinapyl alcohol

Lecture PBPM - Radical polymerisation of lignin

if l

peroxidase

isomeric forms the coniferyl alcohol radicalsconiferylalcohol

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Lecture PBPM - Lignin monomers and the polymer

compound

p-coumaryl alcoholconiferyl alcoholsinapyl alcohol

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Lecture PBPM - Hypothetical structure of the lignin polymer

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Lecture PBPM - Architecture of a conifer tracheid from Pseudotsuga menziesii

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Lecture PBPM -Lecture PBPM - Lignification as important defence reaction of plants towards pathogens

fungus

epidermal cell

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