The document outlines Assignment #4, which requires a 10-minute presentation on the mint plant, touching on aspects such as its physical structure, environmental factors, responses to stimuli like gravity, light, and touch, and various defense mechanisms against herbivores and pathogens. It describes the mint plant's traits, such as its square stems and lanceolate leaves, along with the abiotic and biotic factors that influence its growth. Additionally, it emphasizes the importance of understanding specific response systems like gravitropism, thigmotropism, and phototropism in relation to the plant's development and defense strategies.

1. Assignment #4 – Presentation
1. Prepare a 10 minute presentation based on your previous 3
assignments (observations, sensory systems, and integration).
You can use comments from the presentations to improve your
thinking.
2. Comment on your classmates’ presentations for full credit.
3. describe the mint plant (shape, color) the physical structure
of this plant, why it looks like this, protein, hormones,
signaling, how does sensory system work?
THE MINT PLANT 1
THE MINT PLANT 10
The Mint Plant
Name: Noura Alzahrani
Final project plant physiology

2. Description of the Physical Structure
The mint (genus Mentha) is a fragrant herb that belongs to the
mint family. This plant has square stems to which leaves are
arranged oppositely to each other. The leaves are lanceolate in
shape and are arranged side by side along the stem. The stem of
the plant is succulent despite the fact that the plant does not
usually grow in a watery environment. Just above the roots, at
the end of the stem, shoots appear composed of small leaves and
a bud. The mint while at its young stages is just a short herb
with an approximated height of 30 centimeters.
The Plant in its larger environment
The abiotic environment
The mint herb is affected by scores of abiotic factors. However,
the plant can survive well under uncontrolled lighting.
Therefore, the light quantity that the plant is exposed to does
not necessarily determine its ability to grow. The mint is
however expected to be grown in an area that has controlled
contact with the wind. The plant sometimes grows tall and
considering its weak stem; then it is clear that the plant will
eventually be broken. Also, there is need to control the
temperatures around the plant (Cohen & Kennedy, 2010). Too
hot temperatures melt the oils covering allowing the plant to

3. lose a lot of water through the process of photosynthesis. In the
same measure, low temperatures, especially during winter, are
quite hard for the plant to survive in.
The mint is less commanded by the biotic environment in which
it is grown. However, botanists who have had a practical
planting of the plant argue that the mint performs better when
planted in a fertile soil that has a pH of 6.0-7.0. It, therefore,
means that the plant thrives in a slightly acidic or neutral soil.
Adding fertilizers to the soil is not advocated for. However, it
does not negatively affect the plant as fertilizer is also slightly
acidic (Cohen & Kennedy, 2010). However, use of natural
mulch such as that of plant leaves is advocated for as it keeps
the soil moist.
Description of the biotic community
The biotic community of the mint plant is limited. There exist
very few biotic factors that affect the mint plant. Among these
factors are the consumers. The consumers are animals that feed
on the plant denying it room for growth. The mint plant is eaten
by small plant-eating organisms that may deny the plant a
chance to grow ("mint | plant," 2017). Where such organisms
such as locusts are encountered, then it is important to conduct
protection mechanisms that prevent the plant from being eaten.
Also, the plant also faces scores of decomposer organisms such
as mushrooms that thrive where mint plants have died and
decomposed.
Challenges faced by the Mint Plant
Mint is a natural hub that grows almost everywhere. The plant
is faced with a few challenges. One is that some people view it
as a weed and end up uprooting it. Also, the plant is mostly
affected by diseases such as the mint rust that makes the plant
to die easily. Due to its good odor, the plant is open to being
affected by pests ("Growing Mint - Bonnie Plants," 2017). The
plant also grows easily and hence may end up infecting the
whole garden with pests that may cause financial losses while
fighting the pests.
Resources available

4. The mint plant is a naturally growing plant. The mint plant does
not, therefore, need extra resources for growth. This plant only
needs the common resources that are utilized by other plants.
These resources, inclusive of water, air and sunlight are always
readily available for the mint plant. It, therefore, grows
everywhere which makes it be branded as a weed. Mostly, the
plant is seen to grown in river beds, swampy and sometimes
dumped areas ("Growing Mint - Bonnie Plants", 2017). This is
because such areas provide an extra resource which is salinity.
Resources available for the plant are therefore the natural
resources inclusive of sunlight, water, and air.
Short-term responses required by the Plant.
The mint behaves similarly to other plants. However, some
difference exists that justifies the plant to be distinct. The plant
is covered by some oily substance over its stem. Therefore, it
reacts to sunlight, water, and temperatures differently. Short-
term responses may amount to dropping of leaves when the
climate is scorching ("mint | plant," 2017). However, this
drooping is not severe since the oily covering protects the stem
and the leaves from high levels of transpiration as a result of
photosynthesis. Therefore, short-term responses expected from
the plants are very minimal.
Long-term Responses
In a long-term evaluation, this plant responds to different
factors affecting it differently. For instance, a long-time
exposure to extreme temperatures would result in the wilting
and consequent dropping of the leaves. Also, long-term
exposure to the extremely humid conditions would affect the
plant, making the flowers, the leaves and also the stem to
wither. Consequently, increased hostile conditions will render
the plant dead over a long period.
Mint plant Response System to Gravity
Mint plant gravity response systems revolve around
gravitropism, which is a response mechanism to gravity as the
stimuli. Sato et.al (2014) educates that, gravitropism is also
referred to as geotropism. Besides, this response system will

5. influence the mint plant's structure. Along with the afore
mentioned, this section seeks to enlighten on gravitropism as a
notable mint plant response systems, and its effect on a mint
plant structure.
Notably, gravitropism is a mint plant response system.
According to Sato et.al (2014), this system responds to an
environmental stimulus- gravity. In the response, a mint plant
will embrace two mechanisms. The two mechanism includes
positive and negative geotropism (Sato et.al, 2014). Sato et.al
(2014) argues that the mint plants roots will exhibit positive
geotropism. On the other side, negative geotropism is exhibited
by the mint plant leaves and stems. Besides, Sato et.al (2014)
enlightens that, the onset of geotropism in a mint plant is during
germination. Seconding the pre-stated, Sato et.al (2014) puts
across that, it is during germination that, the shoots of the mint
plant grow up and for the roots, they grow downwards.
Arguably, gravitropism as a mint plant response system
influences the mint plant structure. According to Sato et.al
(2014), geotropism will influence the mint plant structure
through the two above-mentioned mechanisms- negative and
positive geotropism. Sato et.al (2014) enlightens that, though
geotropism, a mint plant will grow vertically. Sato et.al (2014)
seconds the above through highlight the aspect of earth's
gravity. To support the above, Sato et.al (2014) argues that, if
one plants a mint plant one a bag, and later bends the bag so
that the mint plant slants horizontally, due to geotropism, the
mint plant will later coil and growth vertically. As such, the
vertical growing structure of a mint plant is as a result of
geotropism what is referred to as gravitropism- a mint plant
response system based gravity as an environmental stimulus.
Mint plant Response System to Contact
A mint plant contact response systems are facilitated by
the thigmotropism mechanism, which applies to several mint
plants. According to Braam (2015), the two fore mentioned mint
plant response mechanism revolves around touch as a stimulus.
Besides, this response system is responsible to some of the mint

6. plant's structures. In line with the pre-stated, this section takes
the lane to formulate a discussion that will shed light on this
contextual mint plant response system and how its influences a
mint plant's structure.
To start with, Braam (2015) enlightens that thigmotropism
is a mint plant mechanism in response to touch as a stimulus. It
is worth noting that, the aspect of touch for this response
system refers to the physical touch. Braam (2015) puts across
that, thigmotropism is also referred to as thigmonasty. Braam
(2015) define thigmotropism as the directional growth of a mint
plant in response to the contact arising from another object.
Examples of mint plants parts that embraced this kind of
response include the tendrils. To sum up, Braam (2015)
educates that, a major mechanism relating to thigmotropism in
positive thigmotropism. In positive thigmotropism, the mint
plants will particularly cling to physical structures for instance
walls.
Arguably, thigmotropism will affect the mint plant
structure. In accordance with Braam (2015) argument, when
mint plants parts, such as tendrils, have physical contact with an
object, consequently, the mint plants parts acquire supports. In
acquiring support, more often, the most mint plant parts will
cling or coil on the object. With a solid example of tendrils,
through coiling and clinging on the object the mint plant's
structure is affected- the mint plants tendrils takes a coiling
structure. In conclusion, and based on t the above mentioned, it
is, therefore, evident that thigmotropism will influence a mint
plant's structure.
Mint plant Response System to Light
Notably, the mint plant responds to lights through
phototropism. Hohm et.al (2013) enlightens that phototropism
is a mint plant response system relating to light as an
environmental stimulus. Hohm et.al (2013) puts across that, and
light is a crucial element to a mint plant's life and growth. For
instance, a mint plant requires light for photosynthesis.
Following the pre-stated, Hohm et.al (2013) mentions that mint

7. plants will growth towards where light is found. Besides, it is
worth noting that, phototropism will affect the structure of a
mint plant. Concerning the pre-stated, this section seeks to
enlighten on phototropism as a mint plant response system that
consequently influences the mint plant's structure.
Phototropism is a mint plant response system that relates
to light. It is worth noting that, light is an environmental factor
that affects mint plants growth. As such, in phototropism, light
acts as a stimulus (Hohm et.al, 2013). Arguably, Hohm et.al
(2013) puts across that, phototropism is a directional response
while as photomorphogenesis refers to non-directional response
growth. Besides, phototropism will relate to response,
particularly on the blue-wavelength light. What is more, Hohm
et.al (2013) argues that, for phototropism, since it's a
directional response, mint plants will embrace growing either
away from or towards the light which forms the basis for the
two-phototropism mechanism- negative and positive
mechanism. According to Hohm et.al (2013), stems will
embrace positive phototropism while as negative phototropism
is evident in a mint plant's roots.
Arguably, phototropism will influence mint plants
structure. Based on the fact that this mint plant response system
revolves around mint plants responding to the light direction,
the stem which embraces positive phototropism will respond the
light direction. As a result, a mint plant grows particularly to
the direction of the light. Following the fore mentioned, in
instances where the mint plant is enclosed in a dark area, the
mint plant will either bend towards the light direction. Such
pre-stated bending structure will influence the mint plants
structure (Hohm et.al, 2013).
Mint plant Response System to Defense from Herbivorous and
Pathogens
Notably, War et.al (2012) enlightens that, herbivorous and
pathogens are the two main enemies to any mint plant.
According to War et.al (2012), herbivorous stands as the main
mint plant enemy since either large or small herbivores, they

8. feed on mint plants. On the other hand, according to Taylor et.al
(2014), pathogen, which is disease-causing microorganisms
such as bacteria and fungi will live in a mint plant and
consequently damage the mint plant's tissues. As such,
pathogens and herbivores are major mint plant enemies.
Following the fore mentioned, numerous mint plants have
response systems that seek to respond to the two above
mentioned enemies- pathogens and herbivorous. In line with the
fore mentioned, this section seeks to shed light on the mint
plant response systems in defending them against the attackers
such as pathogens and herbivorous.
To start with, in for the defense response system, the mint
plant has barriers. These barriers are both impenetrable and
intact (War et.al, 2012). There are various ways relating to
impenetrable barriers. First, some mint plants have bark that
protects them from the predators. Besides, War et.al (2012)
educates that, mint plants have defense responses such as thorns
and spines. Spines are modifying leaves while as Thorns are
modified branches (War et.al, 2012). Besides, mint plants
defensive response will also entail the presence of secondary
metabolites. Secondary metabolites are more often toxic or
alkaloids which offer defensive response to the mint plant's
herbivores stimuli.
What is more, mint plants will respond using various
defensive mechanisms to the pathogens as stimuli. According to
Taylor et.al (2014), a major defensive response to pathogens
stimuli by mint plants is through the use of long-distance
signaling elicit. For the pre-stated method, Taylor et.al (2014)
enlightens that, the defensive respond seeks to deter predators
through a major compound known as jasmonates.
Specific and Various Aspect in the Four Mint plant Response
Systems
Arguably, the above four mentioned mint plant response
systems proper functioning, that is in responding to their
relevant stimuli is aided by the various and specific aspects
comprising the response systems. For instance, for the mint

9. plant defense response system, the systems will require
jasmonates as well as alkaloids to respond to the stimuli of
pathogens and herbivorous respectively. In accord to the above
mentioned, there hence the need to understand the various and
specific aspects that comprise each of the four contextual mint
plant response systems. As such, this section seeks to offer a
detailed and extensively researched discussion that will
enlighten on the various and specific aspects in each of the four
contextual mint plant response systems that aid in the
functionality of the systems.
The Components of Mint plant Response System Light
The proper functioning of phototropism is aided by
various components. To start with, Hohm et.al (2013) puts
across that, phototropism on the onset mediated by different
photoreceptors. Hohm et.al (2013) enlightens that the fore
mentioned photoreceptor are comprised of proteins. These
proteins are covalently bonded to chromosphere. The
chromosphere is a pigment that absorbs light (Hohm et.al,
2013). A combination of both the protein and the chromosphere
forms the chromoprotein.
Besides, the mint plant light response system also has
photoreceptors. According to Hohm et.al (2013), the sensory
photoreceptors are located in two regions. The regions include
the violet-blue region and the red/far- red region. Notably, the
sensory photoreceptors absorb light in the above two mentioned
regions. It is worth noting that, the above-mentioned regions are
located in the visible light spectrum. What is more, according to
Hohm et.al (2013), this particular response system also
comprises of phytochromes, which is chromoproteins family.
Arguably, Hohm et.al (2013) notes that the phytochromes are in
two forms, the Pfr and Pr. the Pfr is an active physiological
protein form.
In addition, this mint plant response system also is
comprised of other aspects such as the phototropism. Hohm
et.al (2013) enlightens that the phototropism is particularly
protein-based receptors. These protein-based receptors are

10. particularly responsible for mediating the phototropic response
(Hohm et.al, 2013). Arguably, Hohm et.al (2013) notes that,
since phototropic is a receptor, it will comprise of the protein,
chromosphere.
Components in the Mint plant Response System to Gravity
Notably, geotropism is aided by various components. To
start with, this response system has plastids. For instance, Sato
et.al (2014) mentions amyloplasts as an example of specialized
plastids located in the mint plant response system to gravity.
The response system also comprises of starch granules which
are particularly located in the amyloplasts. Sato et.al (2014)
puts across that the fore mentioned amyloplasts are found in a
mint plant's shoots which aid geotropism.
Besides, in this contextual mint plant response system,
there are secretions of calcium ions. These calcium ions are
secreted during the geotropism mechanism by the endoplasmic
reticulum. What is more, there is the response system includes
secretion of Indole-3-acetic acid. It is worth noting that, the
Indole-3-acetic acid is a mint plant hormone particularly of the
auxins class. In relation to the Indole-3-acetic acid, Sato et.al
(2014) notes that their high concentration of in roots will
particularly exhibit cell elongations. Contrary, in the stem, the
high concentration will promote cell elongation. The above
hence agrees to the two mechanism of geotropism- positive and
negative geotropism. To sum up, the mint plant response system
to gravity is composed of aspects such as plastids, starch
granules, calcium ions secretions, endoplasmic reticulum and
hormones such as Indole-3-acetic acid.
Components of the Mint plant Response System to Contact or
Touch
The mint plant response system to touch and contact is
facilitated by the thigmotropism mechanism. Arguably, proper
functioning of the thigmotropism mechanisms is aided by
various components in the mint plant response system to touch
and contact. To start with, the mint plant response system has
specialized structures. For instance, Markovic et.al (2016)

11. mentions that the Venus fly trap, have tiny hairy structures that
are particularly located inside the leaves trap. Besides, the mint
plant response system also has glands. According to Markovic
et.al (2016), these glands will secrete enzymes. For instance,
pulling back to the previous contextual example, the Venus fly
trap after an insect touches it, the leaves will close, and the
glands secrete enzymes that digest the insects. However,
Markovic et.al (2016) notes that the enzymes secreted will not
necessarily act similar to the Venus fly trap case.
On the other side, for the mint plant response system to
contact, that is thigmomorphogenesis, which will affect the mint
plant shape, the system will include components such as xylem.
According to Markovic et.al (2016), xylem is a strengthening
tissue that is produced particularly to add stiffness as well as
resist any agents such as the wind that may result to the
collapsing of the mint plant- for instance, tendrils.
Components of the Mint plant Response System on Defense
Pulling back to the fore mentioned, mint plants have a
defense response system to two notable enemies – pathogens
and herbivorous. The mechanism responsible for this response
is aided by various components within the mint plant defense
response system. To start with, the mint plant defense response
systems includes enzymes and toxins. War et.al (2012) argues
that there enzymes and toxins are secreted by the mint plants for
defense mechanisms in case the first line of defense is distorted.
Besides, the mint plant defense response system also
comprises of metabolites. According to Taylor et.al (2014), a
solid example of secondary metabolites includes alkaloids- they
produce noxious odors. What is more, this response system also
has long-distance signaling elicits for instance jasmonates (War
et.al, 2012).
Concept Map
Herbivorous
Sun and light devices

12. Photosynthesis
LIGHT
Alkaloids
Noxious odor
Pathogens
Jasmonates
Enzymes
Phototropism
ROOTS
Defense
THIGMOTROPISM
CONTACT
MINT PLANT
POSITIVE
GEOTROPISM
GEOTROPISM
SOIL

13. Explanation
Notably, the above concept map seeks to shed light in a more
practical platform, the linkages of the four crucial Mint plant
response systems. The four response systems include response
systems to light, contact, gravity as well as defense. It is worth
noting that, for defense, the response systems targets two
aspects- herbivorous and pathogens. In line with the fore
mentioned, this section seeks to explain the above concept map
through analyzing the linkages.
To start with, the concept map illustrates that, the mint plant is
the source of the linkage between all the response systems.
Arguably, all the response systems, that is, from the response
system of light to the response system of defenses arise from
the plant. As such, the plant is the source of the above-
illustrated response systems.
In addition, the above response systems seek to aid in the
growth of the mint plant. Lux & Rost (2012) educates that,
response systems helps and facilitates the growth of plants.
Similarly, as illustrated by the above concept map, the
responses systems will converge to the mint plant, which will
aid in the growth of the mint plant.
Besides, the above concept map illustrates that the response
systems will facilitate two major aspects in a mint plant growth.
To start with, the responses system facilitates various plants
process. For instance, in accordance with the concept map, the
mint response system to light will acquire light which is crucial
for photosynthesis (Hohm et.al, 2013). Arguably, Hohm et.al
(2013) notes that it is through photosynthesis that the mint plant
acquires food which is crucial for its growth. Besides, on the
response systems to gravity, it helps the root grow downwards
to soil, which in turn helps the plant acquire nutrients.
According to Lux & Rost (2012), the mint plant requires
nutrients for its growth. Besides, roots will also help the plant
acquire water.
What more is, proper functioning of the response systems is
aided by various aspects. A major aspect that aides the proper

14. functioning of the response systems is the mechanisms.
Arguably, every response system has a mechanism, which is
unique. For instance, the response system to light is aided by
the phototropism mechanism while as the mint plant response
system to gravity is aided by geotropism. Besides, each
mechanism is also aided by various aspects such as mechanism.
For instance, thigmotropism, which is a mechanism in relation
to mint plant response system to contact is aided by secretion of
xylem tissues (Chehab et.al, 2010). Another notable example is
the mint defense response system to defense by pathogens
which is aided by jasmonates and enzymes (War et.al, 2012).
The mint plant has four main response systems. These response
systems respond to four main stimuli which include light,
gravity, contact as well as the defense against both pathogens
and herbivores. Notably, for each response system, the mint
plant will use a significant mechanism .the above concept map
illustrates, the mechanisms that the mint plant embraces in the
response system to the four mentioned stimuli. Besides, the
concept map also sheds light on the various aspects of each
mechanism and what the mechanism seeks to respond to. To
sum up, the above contextual concept map has helped illustrate
the mint plant response systems to the four main stimuli-
contact, light, gravity and defense to both herbivorous and
pathogens.

15. References
Chehab, E. W., Eich, E., & Braam, J. (2010).
Thigmomorphogenesis: a complex plant response to
mechano-stimulation. Journal of experimental botany, 60(1),
43-56.
Lux, A., & Rost, T. L. (2012). Plant root research: the past,
present, and also the future. Annals of Botany, 110(2), 201-204.
Hohm, T., Preuten, T., & Fankhauser, C. (2013). Phototropism:
translating light into directional growth. American Journal of
Botany, 100(1), 47-59.
War, A. R., Paulraj, M. G., Ahmad, T., Buhroo, A. A., Hussain,
B., Ignacimuthu, S., & Sharma, H. C. (2012). Mechanisms of
mint plant defense against insect herbivores. Mint Plant
signaling & behavior, 7(10), 1306-1320.
Taylor, J. Hatcher, P.& Paul, N. D. (2014). Crosstalk between
mint plant responses to pathogens and herbivores: a view from

16. the outside in. Journal of experimental botany, 55(395), 159-
168.
War, A. R., Paulraj, M. G., Ahmad, T., Buhroo, A. A., Hussain,
B., Ignacimuthu, S., & Sharma, H. C. (2012). Mechanisms
of mint plant defense against insect herbivores. Mint plant
signaling & behavior, 7(10), 1306-1320.
Hohm, T., Preuten, T., & Fankhauser, C. (2013). Phototropism:
translating light into directional growth. American journal of
Botany, 100(1), 47-59.
Markovic, D., Nikolic, N., Seisenbaeva, G., & Ninkovic, V.
(2016). Mint plant Responses to Brief Touching: A
Mechanism for Early Neighbour Detection?. PloS one, 11(11),
e0165742.
Sato, E. M., Hijazi, H, Vissenberg, K., & Swarup, R. (2014).
New insights into root gravitropic signaling. Journal of
experimental botany, eru515.
Braam, J. (2015). In touch: mint plant responses to mechanical
stimuli. New Phytologist, 165(2), 373-389.
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