1. Plant Structure and Growth

7/25/2019 1. Plant Structure and Growth

1/70

Last Updated:June 25, 2016 LMS SEGi education group 1

PLANT ANATOMY AND PHYSIOLOGY

WEEK 1 WEEK 2

!"ant #or$ and #unction


2/70


LE%&'('G )*JE+(-ES

Understand t.at t.e p"ant structure consists o/ &oots,Ste$s and Leaes

*e aare o/ t.e /unctions o/ t.e roots, ste$s and "eaes

Kno t.e transport o/ ater and /ood sustances in

p"ants and .ere t.ese occur

Kno so$e p"ant respond to t.e eniron$ent 3

p.ototropis$, geotropis$ and tig$otropis$


3/70


LE%&'('G )U+)MES

%t t.e end o/ t.is topic ou s.ou"d e a"e to:

(denti/ and di//erentiate t.e crosssections o/ $onocot

and dicot root and ste$ under t.e $icroscope

State t.e structure and /unctions o/ 7"e$ and p."oe$

(ndicate .ere actie and passie transport occur in a

p"ant8

9escrie t.e di//erent tpes o/ responses seen in p"ants8


4/70

Why are plants important?

#ood

S.e"ter

)7gen !rotection

;aitat

%est.etics


5/70

!"ant $orp.o"og t.e stud o/ t.e e7terna" structure o/

p"ants

!"ant anato$ t.e stud o/ t.e interna" structure

A plant can be divided into 2 basic systems:

Terrestrial plants face a divided habitat:

Each system depends on the other

Shoots provide sugars for roots (viaphloem)

Roots provide H2! minerals and support for shoots (via "ylem)

#$ Root system

2$ Shoot system % stems! leaves & flo'ers

Air source of 2for *HS

Soil % provides H2 and minerals


6/70

The Root System

4 /unctions:#$ Anchor plants

2$ Absorb and conduct H2 & nutrients

+$ Store food

2 ma,or types of root systems:#$ Taproot system

Seen in many eudicots

Some are modified to store much reserve food

2$ -ibrous root system *revent soil erosion

Seen primarily in monocots

Root hairs: enhance H2 absorption by ....................increasing surface area


7/70

The Shoot System

Vegetative shoot = stem + leaves

Floral shoot - terminates in flowers

STEMS -on the shoot tip

-has developing leaves

-a.k.a. axillary bud-embryonic side shoot

-usually dormant

where leaves

attach to stem

Node

Terminal

bud

Lateral

bud


8/70

LEAES

.e $ain p.otosnt.etic organs o/ a p"ant

Usua"" a /"attened blade.ic. is "ea/ ase /or$s a

sheatharound t.e ste$?

Monocot "eaes para""e" $a


9/70


10/70


11/70

(s t.e eaporatie "oss o/ ater/ro$ p"ants

(t is t.e super.ig.a /ornutrient transport+oo"s t.e p"ant)ccurs pri$ari" on t.e "oer

"ea/ sur/ace


12/70

#ig 4@ 10


13/70

#ig8 4@810


14/70


15/70


16/70

TYPES of PLANT

CELLS Note: Structure is related to function.

1. PARENCHYMA CELLS

least specialized plant cells

primary walls are thin, flexible

function - synthesizing and storing organic

products

2. COLLENCHYMA CELLS

wall is uneven in thickness

grouped into strands or cylinders to support young

parts of plants


17/70

3. SCLERENCHYMA CELLS

have very rigid, thick walls strengthened by lignin

function - support

4. WATER CONDUCTING CELLS: Tracheids & Vessel

Elementsdead at functional maturity

Tracheids - long, thin tapered cells; lignin; has pits for

flow of H2O; functions: support &

conduction

Vessel elements - wider, shorter, thinner walled,

less tapered; aligned end to end; end walls

are perforated for H2O flow


18/70

Transport in Plants


19/70


20/70

En!o!ermis " #asparian strip


21/70

Mo$ement o% &ater " Apoplast an!

Symplast


22/70

Apoplast an! Symplast


23/70

Mem'rane Transport

Passi$e Transport( No ener)y re*+ire!, Di%%+sion o% a s+'stan-e %rom a re)ion o%

hi)her -on-entration to one o% lo&er-on-entration &itho+t the help o% anytransport protein,

Osmosis,the mo$ement o% &ater into -ells.is an e/ample o% passi$e !i%%+sion( the

!i%%+sion o% &ater a-ross a mem'rane %roma re)ion o% hi)her -on-entration 0hypotonicor !il+te sol+tion1 to one o% lo&er-on-entration 0hypertonic or -on-entrate!sol+tion1,


24/70


25/70

A-ti$eTransport

18 .e transport o/ sustances /ro$ a

region o/ "oer concentration to a region

o/ .ig.er concentration8

%ctie transport reAuires energ


26/70

A-ti$e Transport


27/70

A-ti$e Transport 2 Passi$e Transport


28/70

.e ra//ic o/ BLargeB Mo"ecu"es

En!o-ytosis an! E/o-ytosis( Me-hanisms%or transport in or o+t

En!o-ytosis( 3 4in!s 0in all. the

e/tra-ell+lar %a-es o% mem'ranes %+se to%orm $esi-les &hi-h enter the -ell5 -ell

al&ays 6sees7 the -ytoplasmi- %a-e1,

A, pha)o-ytosis( 6-ell+lar eatin)7

8, pino-ytosis( 6-ell+lar !rin4in)7


29/70


30/70

Exocytosis:

Essentially the reverse of

endocytosis. For releaseof cellular contentsoutside the cell (here, the

cytoplasmic faces ofvesicle and plasmamembrane fuse, so

secretion can occur).


31/70

3, E/o-ytosis(

Essentially the re$erse o%

en!o-ytosis, 9or release o%-ell+lar -ontents o+tsi!e the -ell

0here. the -ytoplasmi- %a-es o%

$esi-le an! plasma mem'rane%+se. so se-retion -an o--+r1,


32/70

E/o-ytosis(

:se! to e/port materials o+t o% -ell,

Materials in vesicles %+se &ith -ell

mem'rane an! are release! to

o+tsi!e, Tear )lan!s e/port salty sol+tion,

Pan-reas +ses e/o-ytosis to se-rete ins+lin,


33/70


34/70


35/70

SIEVE-TUBE MEMBERS: Food-conducting cells

Are chains of phloem cells that transport sucrose, other

organic compounds and minerals Are alive at functional maturity

Their end walls have pores called sieve-tubes At least one companion cell is connected to each These cells nuclei and ribosomes serve the sieve-tube

member which lack these organelles


36/70


37/70


38/70


39/70

Monocot Stem (xs)

Dicot Stem (xs)


40/70

Dicot Stem (xs)


41/70

M t R t ( )


42/70

Monocot Root (xs)


43/70

(Apoplastic)

(Symplastic)


44/70

Monocot Root (xs)


45/70

Dicot Root (xs)


46/70

Dicot Root Vascular Bundle


47/70

Root Vascular Cylinder and Cortex -- Dicot

Cortex

Endodermis

Xylem

Phloem

Pericycle


48/70

Mass Flow -1

Cort

Endodermis

Xylem

Phloem

Pericycle


49/70

Mass Flow - 2

Cort

Endodermis

Xylem

Phloem

Pericycle


50/70


51/70

In shrubs like this tea plant

(Camellia sinensis), the rootsystem will be more tap root than

fibrous root.

Notice the diameter of this tap

root compared to this manswaist!

But shrubs also generally have

some compromise for uprootingforcesfeeder roots extending

laterally.

Tropical soils are nutrient poor


52/70

Tropical soils are nutrient poor.

Roots must traverse the surface

for minerals, so roots grow on

the surface (no tap root).

So, to keep this tall baobab tree

standing upright, the roots grow

in diameter but only in the

vertical dimensions to formridge rootscalled buttress

roots.

These roots are a meter tall!

These roots inspired gothic

cathedral architects to design

buttress walls.

C h d l hi d i b ll


53/70

https://reader009.{domain}/reader009/html5/0328/5abad96aab0ba/5abad987a09b8.jpg

http://www.oxc.com.hk/raoul_nathalie/gallery/images/04%20Buttress.jpg

Cathedral architects to design buttress walls.

Prop roots


54/70

Pandanus utilis- screw pine

Prop roots

C h d l hi d i ll


55/70

http://www.contrib.andrew.cmu.edu/~ajm/Pages/Graphics/flyingbuttress.JPG

http://williamcalvin.com/BHM/img/FlyingButtressND.jpg

Cathedral architects to design prop walls.


56/70

Monocot Leaf Monocot (cross section)


57/70

Dicot Leaf (cross section)


58/70

Dicot Leaf (cross section)

!L%' G&)W;


59/70

!L%' G&)W;

*egins it. seed ger$ination andcontinues /or t.e "i/espan

Indeterminate growthC continued grot.

as "ong as t.e p"ant "ies

(nd8 grot. is $ade possi"e meristems

M i t


60/70

Meristems; perpet+ally em'ryoni- tiss+es

Meriste$atic ce""s Unspecia"iDed

9iide to generate ne ce""s near t.e groing

point

Apical meristems Located in root tips and s.oot uds

Supp" ce""s /or p"ants to gro in "engt.

Primary growthC e"ongation initiated apica" $eriste$s

/or$s pri$ar tissues organiDed into

t.e 4 tissue sste$s

LATERAL MERISTEMS


61/70


LATERAL MERISTEMS c"inders o/ diiding ce""s e7tending a"ong

t.e "engt.s o/ roots s.oots

add ne "aers o/ ascu"ar tissues

produces toug.er secondar der$a" tissues Secondary growthC increased girt. !+e to

lateral meristems

t.ic=ening o/ roots and s.oots

Gro&th o% Shoots


62/70


Gro&th o% Shoots

PRIMARY GROWTH O9 SHOOTS $ost s.oot e"ongation is due to grot. o/ internodes e"o t.e s.oot ape7 grot. resu"ts /ro$ and it.in t.e internode a7i""arF"atera" uds $a /or$ ranc.es "ater in t.e p"ants "i/e

SE#ONDARY GROWTH secondary plant bodyresu"ts /ro$ secondar grot.

>grot. in dia$eter?

2ndar grot. resu"ts /ro$ 2 "atera" $eriste$s:

vascular cambium produces 2ndar 7"e$ and p."oe$ cork cambium produces a toug., t.ic= coering /or roots and

ste$sH rep"aces epider$is

accu$u"ated "aers o/ 2ndar 7"e$ produces wood.ic. consists $ost" o/ trac.eids, esse" e"e$ents

and /ier

Root Tip Di%%erent


63/70


Root Tip " Di%%erent


64/70

Geotropism

)sere t.e picture e"o8

.e ste$ disp"as negatie geotropis$ecause it gros opposite to t.e pu"" o/ grait

Geotropism


65/70

Root Tip Senses Gravity

Auxin Hormone ProducedAuxin Accumulates on Lower

Growth Inhibited on Lower

Relative to Upper

Root Curves Downward

Geotropism

Root Hairs Increase Surface

AreaRoot Hairs Secrete Acid (H+)

H+Cation Exchange w/Minerals

Mineral Uptake into Roots

Water and Mineral

Uptake

Geotropism


66/70

;or$one au7in rings positie geotropis$

%u7in in.iits grot. o/ root ce""s so t.ece""s in t.e upper sur/ace e"ongate and t.e

root cures donard

%u7in sti$u"ates t.e grot. o/ ste$ ce""sso t.e ce""s e"ongate and cures upard

Geotropism

Phototropism


67/70

W.at causes ce""s in s.ad area o/ ste$ to

e"ongateI .e p"ant .or$one au7in $igrates to s.ad

area causing t.e ce""s to e"ongate

Phototropism


68/70

Thi)motropism

.is is caused uneAua" grot. due to

contact it. so"id o


69/70

Thigmotropism


70/70

&E#E&E'+ES

(ntroductor !"ant *io"og Stern, *id"ac= and Jans=

200, 11t.Ed8, McGra ;i""

(ntegrated *io"og ri"", Enger and &oss 200, 4 rd

Ed8, McGra ;i""

1. Plant Structure and Growth

Documents

Transcript of 1. Plant Structure and Growth