PHARMACOBOTANY LECTURE 4. PLANT TISSUES II.

DERMAL TISSUES OF THE PLANT epidermis: primary dermal tissue of the shoot rhizodermis: primary dermal tissue of the root function: protection, transpiration, gas exchange, photosynthesis, secretion, absorption one layer  tunica (protoderma), rarely more than 1 cell layer (e.g. Ficus, Nerium oleander)

Nerium oleander leaf cross section http://botit.botany.wisc.edu/courses/Botany_130/Anatomy/Leaf/Nerium_3.html

Ficus sp. leaf cross section epidermis

Abies tűlevél km10x upper epidermis + cuticle lower epidermis Abies sp. needle Abies tűlevél km10x upper epidermis + cuticle lower epidermis xeromorphic stomata

Valeriana officinalis root rhizodermis

EPIDERMIS Epidermal cells: tightly linked little cytoplasm, no chloroplast large central vacuole – water storage – protects from desiccation Epidermal cells – additional cell wall materials: cutin (procutin – teichodes – polimerization)  cuticle in the form of layers (pectin, cellulose and cutin) wax, lignin, silicic acid

EPIDERMIS Epidermis cell shapes (height/width): isodiametric: H/W= 1-1.5 anisodiametric: H/W= 1.5-5 prosenchymatic: H/W5 Surface view – anticlinal wall (perpendicular to plant surface): rectangular, wavy, lobate

lobate cell walls

Stomata stoma guard cells ER chloroplasts epidermis cell Kalanchoe sp. epidermis cell stoma neighbor cell Arabidopsis thaliana http://plantscienceimages.org.uk

Stomata Stoma - location: Leaves, young stems (floral leaves, below-ground stems); but never on roots. Astomatic leaf Stomatic leaf: - hypostomatic - epistomatic - amphistomatic

Stomata Stoma position – as related to epidermal cells: mesomorphic – medium level water supply hygromorphic – abundant water supply xeromorphic – dry habitats (stomatal crypt)

mesomorphic stoma position Iris sibirica leaf of Iris sp.

nectary of ‘Freedom’ apple hygromorphic

leaf cross section of Nerium oleander xeromorphic (stomatal crypt)

Stomata On the basis of guard cell structure, and mechanisms regulating the opening and closure of stomatal pore: 1. moss-fern type 2. pine type 3. Amaryllis type 4. grass type 1. Moss-fern type: swelling of guard cells occurs perpendicular to plant surface  thin inner edge of guard cells

Stomata 2. Pine type: - guard cells are sunken - closure between upper thickenings

Stomata 3. Amaryllis type: - angiosperms: most frequent - bean-shaped guard cells, in cross section: or high turgor pressure (high light intensity, high humidity)  guard cells open the pore in a plane parallel to plant surface closed stoma water molecules stomatal pore cellulose fibers open stoma Amaryllis

Agropyron pectiniforme Stomata 4. Grass type: guard cells: dumb-bell shaped, subsidiary cells: triangular or trapezoid Agropyron pectiniforme

Phragmites ep.40x guard cells triangular subsidiary cells epidermis cells leaf epidermis of weed

Zea mays ep.40x triangular subsidiary cells guard cells epidermis cells leaf epidermis of maize

Stomata II. Number and arrangement of subsidiary cells: No subsidiary cell: anomocytic 1 subsidiary cell: desmocytic 2 subsidiary cells: diacytic (perpendicular to guard cells) paracytic (parallel to guard cells) 3 (5) subsidiary cells: anisocytic 6 subsidiary cells: hexacytic More than 6 s.cells: actinocytic, heliocytic, cyclocytic

desmocytic anomocytic diacytic tetracytic actinocytic hexacytic anisocytic

Hedera sp. - anomocytic http://employees.csbsju.edu/ssaupe/biol327/Lab/stomata/stomata-images.htm

Senna sp.: paracytic stoma subsidiary cells Capsella bursa-pastoris: anisocytic stoma http://employees.csbsju.edu/ssaupe/biol327/Lab/stomata/stomata-images.htm

PLANT HAIRS / TRICHOMES

Trichomes Origin: epidermal meristemoids (trichoblasts) Structure: base + stalk + head Aspects of classification: Unicellular - Multicellular Branched - Unbranched Soft - Rigid (calcium carbonate, silicium dioxide) Pointed – Blunt Living (secreting) – Dead

Trichomes LM I. Non-glandular (dead) trichomes: petal (Helianthus) papilla I. Non-glandular (dead) trichomes: Papilla (Plural: papillae) – epidermal protrusions stigma SEM stigma surface in pear flower Cover hairs unicellular (e.g. Boraginaceae – bristles / setae) bifid hairs (e.g. Humulus lupulus) seed hairs (e.g. Gossypium) multicellular (e.g. Verbascum – multi-level, branched) stellate hairs, scales (e.g. Elaeagnus)

Non-glandular trichomes multi-level, branched cover hair bristle/seta papillae unicellular multicellular stellate hair scale Non-glandular trichomes bifid hair

Mentha p.levél derített4x trichomes epidermis cells Mentha x piperita cleared leaf

Zea mays ep.szőrök.40x trichomes epidermis cells maize leaf

Althaeae folium_10x upper epidermis lower epidermis Ca(COO)2 crystals trichomes Althaea officinalis leaf

Non-glandular hairs / Cover hairs Elaeagnus sp.: scales Borago sp. – bristle

Non-glandular hairs / Cover hairs Verbascum sp. multi-level branched hair Humulus lupulus bifid hair

Rosae pseudofructus - trichomes

Trichomes II. Glandular trichomes (living, cytoplasm-containing): Salt-secreting (e.g. Tamarix, Limonium) Nectar-secreting (e.g. Lonicera, Vicia faba) Mucilage-secreting (Rumex, Rheum) Essential oil secreting (Lamiaceae, Asteraceae) Glandular scale (e.g. Humulus lupulus) Colleter (e.g. bud scales of Aesculus) Stinging hair (Urtica) (Tentacles of carnivorous plants (e.g. Drosera, Pinguicula))

II. Glandular trichomes stinging hair colleter capitate glandular hair multicellular, peltate glandular hair (seed hairs: non-glandular)

Glandular hairs Pelargonium sp. capitate glandular hair Artemisia vulgaris 8-celled glandular hair

Glandular hairs Juglans regia multi-cellular capitate glandular hairs Salvia sclarea capitate glandular hairs

Glandular hairs Salvia nemorosa – leaf cross section Lamiaceae type glandular hair (glandular scale) Thymus vulgaris – surface view Lamiaceae type glandular hair

glandular trichomes Flower of mallow

Glandular hairs Urtica dioica: stinging hairs (large hairs) and cover hairs (small hairs)

Urtica csalánszőr20x stinging hair head epidermis

stinging hairs

tentacles of insect-trapping sundew (Drosera) Trichomes Emergences: superficial outgrowths – more complex than trichomes epidermis + ground tissues (vascular tissues) Drosera spatula tentacles of insect-trapping sundew (Drosera) prickle of rose Indument(um): all the hairs of a plant

Secondary dermal tissue / Periderm Stems and roots with secondary thickening: – in the place of primary dermal tissues (epidermis, rhizodermis) - perennial gymnosperms and dicots (angiosperms) Primary dermal tissue torn off → traumatins, kinetins Primary cortex: reembrionalisation → secondary meristem phellogen / cork cambium:  phellem / cork  phelloderm / cork ground tissue periderm

Secondary dermal tissue / Periderm Bark/Cortex/ Rhytidoma: periderm torn off  new cork cambium  new periderm Frangulae cortex Quercus cortex periderm elements are mixed with phloem elements: bark / cortex: glycosides, tannins, crystals, alkaloids, resin Lenticels: below stomata – lenticel cambium  loose cell aggregation – ensures gas exchange end of vegetation period: covering cork layer

primary cortex phellem/cork phellogen/ cork cambium phelloderm parenchyma

rhytidoma cork cambium bark of Frangula alnus

Quercus suber cork oak