plant kindom

Plant Morphology
& Anatomy
Plant Organs


Types of Plant Organs
Types of Plant Organs

Vegetative organs:
Vegetative organs:

Roots
Roots

Leaves
Leaves

Stems
Stems

Reproductive organs:
Reproductive organs:

Flowers
Flowers

Fruits
Fruits

Plant Body Systems
Plant Body Systems

The plant body is
The plant body is
organized into a root
organized into a root
system and a shoot
system and a shoot
system:
system:

Root system is generally
Root system is generally
below ground.
below ground.

Shoot system consists of
Shoot system consists of
vertical stems, leaves,
vertical stems, leaves,
flowers, & fruit s that
flowers, & fruit s that
contain seeds.
contain seeds.


Root System
Root System
“

“
absorbtion” and “anchorage” …
absorbtion” and “anchorage” …


The Root System
The Root System

Although we do not see
Although we do not see
much of roots, they are
much of roots, they are
equally important to plant
equally important to plant
growth as stems and leaves
growth as stems and leaves
…
…

Leaves collect light and CO
Leaves collect light and CO
2
2


to produce sugar for growth
to produce sugar for growth
as long as the plant can get
as long as the plant can get
enough water and nutrients from

enough water and nutrients from
its roots
its roots
!
!


Types of Root Systems
Types of Root Systems



A true root system consists
A true root system consists
of both primary & secondary
of both primary & secondary
roots (lateral roots)
roots (lateral roots)

Primary root system:
Primary root system:

Taproot System*
Taproot System*

Fibrous Root System**
Fibrous Root System**

Adventitious Roots**
Adventitious Roots**

*Found in most
*Found in most
dicots
dicots


**Found in most
**Found in most
monocots
monocots




Primary Root System
Primary Root System

The 1
The 1
st
st
root to emerge
root to emerge
from a seed is the
from a seed is the
radicle
radicle
(primary root), which
(primary root), which
emerges to form a

emerges to form a
taproot that persists
taproot that persists
throughout the life of the
throughout the life of the
plant.
plant.

Many progressively
Many progressively
smaller
smaller
branch roots
branch roots
(lateral roots)
(lateral roots)
grow
grow
from the taproot.
from the taproot.


Taproot System
Taproot System

Definition
Definition
: the root system
: the root system
consisting of a thick,

consisting of a thick,
central
central
primary root
primary root
, which forms
, which forms
many smaller
many smaller
lateral roots
lateral roots
.
.

Common in dicots and
Common in dicots and
conifers.
conifers.

In some plants such as
In some plants such as
carrots and beets, fleshy
carrots and beets, fleshy
taproots are the plant’s
taproots are the plant’s
“food pantry”.
“food pantry”.

In other plants the long
In other plants the long

taproots are modified for
taproots are modified for
reaching water deep in the
reaching water deep in the
ground.
ground.


Fibrous Root System
Fibrous Root System

Definition
Definition
: root system that
: root system that
consists of several to many
consists of several to many
roots of
roots of
the same size
the same size
that
that
develop from the end of the
develop from the end of the
stem with smaller, lateral
stem with smaller, lateral
roots branching off of
roots branching off of
them.

them.

Typically slender, small roots
Typically slender, small roots

Found in monocots like
Found in monocots like
onion, sweet potatoes, etc…
onion, sweet potatoes, etc…

Form in plants in which the
Form in plants in which the
embryonic root is short-lived.
embryonic root is short-lived.


Fibrous Root System
Fibrous Root System

Most fibrous roots are
Most fibrous roots are
very extensive and cling
very extensive and cling
to soil particles, >>>
to soil particles, >>>
can be used for
can be used for
preventing erosion.
preventing erosion.


Fibrous roots do not
Fibrous roots do not
arise from preexisting
arise from preexisting
roots but rather from
roots but rather from
the stem.
the stem.


Adventitious Roots
Adventitious Roots

Definition
Definition
: roots that arise
: roots that arise
on organs other than roots
on organs other than roots

Usually begin growing after
Usually begin growing after
the seed germinates
the seed germinates

They form in all sorts of
They form in all sorts of
places on plants including
places on plants including
leaves, petioles, and stems.

leaves, petioles, and stems.


Adventitious Roots
Adventitious Roots


Why Different Root Types?
Why Different Root Types?

Help plants compete for water and minerals
Help plants compete for water and minerals
…
…
- Shallow, wide-spreading fibrous roots: <15 cm deep
- Shallow, wide-spreading fibrous roots: <15 cm deep
- Medium-depth, evenly distributed fibrous roots (<1.5 m
- Medium-depth, evenly distributed fibrous roots (<1.5 m
deep)
deep)
- Deep taproots (lack width, but go deeply)
- Deep taproots (lack width, but go deeply)


Root Functions
Root Functions
Primary & Specialized
Primary & Specialized

Primary Root Functions
Primary Root Functions

Roots perform 4 main functions:
Roots perform 4 main functions:

Absorption/Conduction of water
Absorption/Conduction of water
and dissolved minerals
and dissolved minerals

Anchorage
Anchorage

Storage (carbohydrates)
Storage (carbohydrates)

Production of hormones
Production of hormones
(e.g.,
(e.g.,
gibberellins) &
gibberellins) &
secondary plant
secondary plant
compounds
compounds
(e.g., nicotine in
(e.g., nicotine in
tobacco plants)

tobacco plants)

Some specialized roots are
Some specialized roots are
modified for other functions ….
modified for other functions ….