-

only 2% Of total water absorbed by plants utilized in Factor : ↑ temp ,

↑ air movement ,
↓
humidity ,
↑
light intensity Abscisic acid → Plant hormone ; abscisic acid ,
causes kt to pass out guard

photosynthesis & nearly 98% lost in form vapors via process low coz =
large open cells to surrounding cell

called plant transpiration high coz

=
small open → water inside guard cell higher >
surrounding cells ,
water from
↳
by plants return Hzo →
atmosphere guard cell move →
surrounding cells & cause guard cells become

via stomata Factors in regulation of stomata open / close flaccid & thus stomata closed

1 water in soil • 2 Root hair • 3 Root cortex o 4

Xylem
-

involve changes in turgor pressure I pressure potential I guard cells during daytime 10,10W Concert •
plant can detect this ,
stomata open to allow co , → enter for photo -

5 upward movement o b leaves an Diffusion through stomata &

nighttime results potassium 1kt ) ions synthesis

through xylem -

During daytime guard cells take up rations from surrounding cells

[ more K+ ions & has low water

10 , high concert °
cause stomata close CO2 increase acidity guard cells by increasing H'
-

concern

become turgid & stomata opens

stomatal pores ) H+
open to take in co , and Due to increase in in guard cells guard cells become
-

more are open ,

°
concert .

,
cause

more plants transpire & lose water -

In dark no accumulation ñ ions in guard cell due to K+ ions are transported flaccid & stomata closed
,

from guard cell →

surrounding cells

i. unction " """ " " " ""' " " Auxin •
plant hormone produced in shoot & apical meristem

activated proton pumps H+ out guard cell

•

1 main functions is cool plant sweat keeps humans & animal

PLAN -1 TRANSPIRATION uptake K+ guard water in peripheral cell guard

• →
→ cell ,
cell & caused

cool guard cell become turgid & thus stomata opened

L if
cannot transpire enough to keep cool in dry soil i extreme

heats then losing leaves / completely defoliate in

guard cell low Kt ↑ H2O water from cells , affecting plant transpiration
start & move
guard cell →
surrounding Factors rate
-

, ,

↓
severely stressed and die thus guard cells become flaccid & stomata closed

l
plant transpiration is evaporative cooling system brings 1 Temperature -
rates go up as temp .
↑
,
air warmer due to stronger sunlight &

down temp plants .

,
but since leads → water loss Drought °
there is lack ground water
,
stomata will close to prevent water warmer air masses

↓
by guard toss through transpiration
dehydration
regulated cell to open / close stomatal mins pores I 1
regulatory mechanism to prevent

, 2 Humidity -
relative this of air surrounding plant rises transpiration rate falls
,

2 involved in pumping new water & minerals to leaves

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Yin
for Iban :ÑbbÑI Cold weather / winds tend to closed rapid
±¥
°
cold weather , strong ,
stomata coz greater outside

leaf
low temp water from reduce traspi ration
. loss guard cells & rate

1
Dry air 0 2 loss water from leaves → 3 New water °
low temp plants always dehydrate coz restricted water uptake
⇐É ↓

,
Humidity
stoma always rapid lose

Regulation of transpiration 3 Wind & air movement -

increased movement wind & air around plant result in
higher transp i -

Pathogen ° Bacteria & fungi capable of triggering stomatal closure through patho -
ration rate

-
stomata open / close depend on light intensity , high temp ,

, gen
-
associated molecular patterns ( PAMPs ) , prevents penetration through
E.

/
§
wind ,
relative humidity & coz concentrations in atmosphere these pores s

¥
§
→ stomata considered part of plant innate immune response É
oÉ
wind velocity
 4 Soil -
moisture availability -
soil moisture lacking ,
result in leaf loss &
plant

transpire less water Another type of water loss from plant

stem
How transpiration is measured ?
/ " "" "

lenticel -
found on epidermis of diff plant organist
l fruits

limitations

-
measures water uptake of gases between internal tissue
-

exchange env .
&
spaces organs

cutting plant shoot damage plant 0, & water

entrance & simultaneously output coz vapor
-

plant has no roots ino resistance to

_
In apple ,
account for up 21% transpiration
H2O being pulled up
, ,ype of plant -

grow in arid regions " " " """ • " " " " "" """"ᵈ

water by transpiring less water > other plants by having

waxy cuticle & epidermal hair

PLAN -1 -1µg µ J PIRA / [ ON

Guttation -
water lost from leaves in form liquid droplets from tips &
margins

leaves at night

-
uncontrolled process
 Plants have adapted to transport water , minerals from roots to leaves what is symplast Gaspari an strip -
band -
like thickening of lignin & suberin in

sugars from specific

←

& leaves →
areas
-
consists of cytoplasmic network every plant cell interconnected by plasmodesmata root endodermis

sym plastic route utilised to deliver H2O & ions

How do roots absorb water & minerals beyond cortex . mad up non-living components

Root morphology

-
does not involve intercellular spaces & cell walls & considered as complete living component

plant tissue

Pericycle -
cylinder parenchyma / sclerenchyma cells lies just

inside endodermis & outer most part of stele of plants

"" "" "" "

PLANT TRANSPORTATION
What is Apop last ?

space outside plasma membrane consisting intercellular spaces material diffuses freely
-

How do roots absorb water & minerals ? -

does not involved protoplasm in plant tissues but involves non-living parts plant ; How do roots absorb more water & minerals ?

[ cell wall & intercellular spaces

I

I
Active absorption →
Hzo it enters cell sap &
passes from 1 cell → another -

In pathway , Hzo transported from root hair →

Mycorrhizal mutualism ( Fungus + root hairs I

→
protoplasm involved called symplast Xylem through cell wall fungus helps plant obtain more water & minerals
-

Beyond cortex , apo plastic H2O movement blocked Plant feeds sugar →
fungus
-
-

[
"" " " " "" " " "" ° " → ""° " °"" "" " ° " ""° """ °" " " "° " "" " " " " " " " " "" " " " ""

→
apop last path includes cell wall & intercellular spaces

Sym Plast & Apop last → 2 separate pathways in plant initiate passage water

along w/ ions from root hair cortex → xylem elements

→ routes exist either simultaneously / separately having

diff rates
 Mechanism transportation water & minerals Respiration 3 water enter from xylem → sieve element by osmosis due to concentration

by
[ Transpiration cause area low pressure within plant
glucose + oxygen • carbon dioxide + water +
energy inside sieve elements increase phloem loading
✓
loss water through stomata

§
-
in leaves occur in mitochondria ein cells

-
root pressure creates higher pressure & thus Hyo •
Plants use some glucose produce respiration 4 hydrostatic pressure forces solute to next sieve tube

goes up
•
Chem reaction releases energy allows to convert rest glucose into other useful substances thus diff drive solute movement to sink

-
water moves from high pressure from soil → can use to build new cells &
grow

low pressure in plant xylem The store carbohydrates as starch 5 Ploem unloading

l transfer organic food from sieve tube → sink ( root / fruits site storage
,

cohesion -
allows Hzo against gravity CO2 Hyo molecules are -

process in food
lsugari made in leaves l
sugar gradient from source creates pressure flow via sieve tube towards sink

polar have week bonds between molecules cohesive -

can downward , upward & lateral

force holding molecules together -

downward from leaves → stem & root
, upward from leaves → buds flowers
,
& fruits 6 decreases concert .
in sieve tube & water move back

Hyo molecules stick to 1 another through cohesion lateral from pith → cortex & epidermis

www.ninmiem.a " " """ "" "" " " " "
-
in plants ,
takes place by vascular tissue called phloem

www.n.mn ,

Tension adhesion /
,
-
water molecules climb on top by H2O PLAN -1 1- RANJI C) (A) [ON -

capillary action attracted to walls xylem

How do plant transport food ? Mass flow / pressure flow hypothesis

produce carbohydrates ( sugars ) in leaves by Ñ9bnd1:ÑbbÑI , but non -

-

mainly concerned w/ explanation of movement sugar via phloem in plant

ÑII nil :ÑuÑI also require carbohydrates

-

2 importance terms in mass flow hypothesis ; source & sink

-
Glucose formed by photosynthesis in cells mesophyll & some glucose utilized
-
source is site synthesis / green parts plant like leaves

-
leftover glucose transformed into sucrose -
sink is site storage like fruits , seeds & tubers

what do plants glucose for Mechanism of

?
use mass flow hypothesis

used straight away in respiration Plants.

also carry out respiration 1
sugar in mesophyll cells increase by photosynthesis

to release energy l
water then absorbed from nearby cells ,
&
increasing hydrostatic pressure in mesopnyll cell

substances for Stores of energy

-

converted into starch & Other storage .

1
Hydrostatic / turgor pressure is exerted on wall due to entry of water by osmosis

used later when plant needs them

fats
-

used to make new chemicals ; proteins , sugars & 2 Phloem loading occur

l transfer food from

organic me Sophy 11 cells •
companion cell & sieve tube phloem due to

hydrostatic / turgor pressure