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PHOTO BIOLOGY IN PROPHETOPATHY
I I M S submission to W H O
Muslims often pride themselves with the claim that what sets them
apart from people belonging to other religions is their ability to
sustain a concrete relationship between science and religion. The
first command the prophet received from God was "read" enunciated in
the Quran’s 96th chapter. Despite the debate the surrounds the
interpretation (tafsir) of that particular command, Muslims find
comfort in asserting that it is an indication that Islam is a religion
of "reading". What follows is an Islamic quest for knowledge whether
is in the field of math, physics, astronomy, economics or even
medicine.
In that regards, Muslim scientists often find guidance in the words
and practices of the Prophet Mohammad. The prophet did not confine his
dealings with religion only; he also sought to address the various
aspects of a Muslims life. Most important of these aspects is how to
can a Muslim sustain a healthy life. Prophetic medicine refers to the
actions and exact words of the prophet dealing with sicknesses,
hygiene, and health in general. According to the prophet, for every
disease there is a cure. Therefore, prophetic medical traditions do
not stop at following the teachings of the prophets; they encourage
humans to search for cures as well.
Following the prophet’s death, many scholars who have been influenced
by the prophetic tradition actively sought to follow the prophet’s
words and research by any means possible for different cures and
medicinal procedures. For example, Ibn Qayyim Al Jawziyya produced one
of the most important works about "al Tibb-ul-Nabbawi." in his
277-chapter book, AL- Jawziyya deals with different treatments of
individuals as recommended by the prophet. It also talks about
malpractice and hallmarks of competent doctor.
Al-Jawziyya identifies specific remedies recommended by the prophet
and deals with pharmacological studies on the use of various herbs and
natural substances. Al-jawziyya also elaborates on the relation
between medicine and religion. 'Abd-ul-Rahman ibn abi Bakr al-Suyuiti’
wrote multiple of readings on prophetic medicine. He composed two
works on prophetic medicine. One contained the practices of medicine
by Mohammad and a second on sexual relations as ordered by the
prophet. Al Suyti’s book divides medicine into 3 types:traditional,
spiritual and preventive. He listed preventive medical measures such
as food and exercise. Others taught by hadith such as epidemics, use
of tooth stick (siwak) and other practices.
It is worth to mention that some of theses practices have been adopted
by modern medicine and have been tested in many researches centers
around the world. For example, many institutions in Egypt are involved
in research on traditions remedies and many medicinal plants like the
black seed is being investigated and commercialized.
The black seed is an example of a prophetic remedy that has been
studies by Muslims and not Muslims. In conclusion, prophetic medicine
is an authentic and valid medical system which produced remedies that
have been considered as legitimate and groundbreaking by various
scientists and research. Further research about prophetic medicine is
being conducted in various labs around the world and the results of
these research continue to be to surprising even to the most keen
scientist.
Biophoton/Al alaq
----------------
A biophoton (from the Greek βιο meaning "life" and φωτο meaning
"light"), synonymous with ultraweak photon emission, low-level
biological chemiluminescence, ultraweak bioluminescence, dark
luminescence and other similar terms, is a photon of light emitted
from a biological system and detected by biological probes as part of
the general weak electromagnetic radiation of living biological cells.
Biophotons and their study should not be confused with
bioluminescence, a term generally reserved for higher intensity
luciferin/luciferase systems.
Biophotonics is the study, research and applications of photons in
their interactions within and on biological systems. Topics of
research pertain more generally to basic questions of biophysics and
related subjects - for example, the regulation of biological
functions, cell growth and differentiation, connections to so-called
delayed luminescence, and spectral emissions in supermolecular
processes in living tissues, etc.
The typical detected magnitude of "biophotons" in the visible and
ultraviolet spectrum ranges from a few up to several hundred photons
per second per square centimeter of surface area, much weaker than in
the openly visible and well-researched phenomenon of normal
bioluminescence, but stronger than in the thermal, or black body
radiation that so-called perfect black bodies demonstrate. The
detection of these photons has been made possible (and easier) by the
development of more sensitive photomultiplier tubes and associated
electronic equipment.
Biophotons were employed by the Stalin regime to diagnose cancer, and
their discoverer, Alexander Gurwitsch was awarded the Stalin Prize.
Although the method has not been tested in the west, the biophoton
concept has been appropriated into the pseudoscientific jargon of
alternative medicine, for example to supply a basis for supposed
natural cures for cancer
In the 1920s, the Russian embryologist Alexander Gurwitsch reported
"ultraweak" photon emissions from living tissues in the UV-range of
the spectrum. He named them "mitogenetic rays" because his experiments
convinced him that they had a stimulating effect on cell division.
(see Morphogenetic field) However, the failure to replicate his
findings and the fact that, though cell growth can be stimulated and
directed by radiation this is possible only at much higher amplitudes,
evoked a general skepticism about Gurwitsch's work. In 1953 Irving
Langmuir dubbed Gurwitsch's ideas pathological science.
But in the later 20th century Gurwitsch's daughter Anna, Colli,
Quickenden and Inaba separately returned to the subject, referring to
the phenomenon more neutrally as "dark luminescence", "low level
luminescence", "ultraweak bioluminescence", or "ultraweak
chemiluminescence". Their common basic hypothesis was that the
phenomenon was induced from rare oxidation processes and radical
reactions. Gurwitsch's basic observations were vindicated.
Proposed mechanism
-------------------------------------
Chemiexcitation via oxidative stress by reactive oxygen species(ROS)
and/or catalysis by enzymes (ie peroxidase, lipoxygenase) is a common
event in the biomolecular milieu. Such reactions can lead to the
formation of triplet excited species, which release photons upon
returning to a lower energy level in a process analogous to
phosphorescence. That this process is a contributing factor to
spontaneous biophoton emission has been indicated by studies
demonstrating that biophoton emission can be attenuated by depleting
assayed tissue of antioxidants or by addition of carbonyl derivitizing
agents]. Further support is provided by studies indicating that
emission can be increased by addition of reactive oxygen species (ROS)
.
Since there is visible bioluminescence in many bacteria and other
cells it can be inferred that the (extremely small) number of photons
in ultra-weak bioluminescence is a random by-product of cellular
metabolism. Cellular metabolism is thought to occur in steps, each
involving small energy exchanges.(See ATP) Due to a certain degree of
randomness, according to the laws of thermodynamics (or statistical
mechanics), it must be expected that some irregular steps will
occasionally occur, "outlying states" in which, due to physiochemical
energy imbalance, a photon is emitted.
Statistical mechanics in modern biology often favours an ensemble
model of systems due to the large numbers of interacting molecules,
etc. In chaos theory, for example, it is often suggested that the
apparent randomness of systems is due to a lack of understanding of
the larger system of which the given system is a component. This has
led many who deal with large systems to employ statistics to explain
seemingly random events as outlying effects in probability
distributions.
Hypothesized involvement in cellular communication
In the 1970s the then assistant professor Fritz-Albert Popp, and his
research group, at the University of Marburg (Germany) showed that the
spectral distribution of the emission fell over a wide range of
wavelengths, from 200 to 800 nm. Popp proposed that the radiation
might be both semi-periodic and coherent. This hypothesis has not won
general acceptance among scientists who have studied the evidence.
Popp's group, however, constructed, tested, patented, and sought to
market a device for measuring biophoton emissions as a means of
assessing the ripeness and general food value of fruits and
vegetables.
Russian, German, and other biophotonics experts, often adopting the
term "biophotons" from Popp, have theorized, like Gurwitsch, that they
may be involved in various cell functions, such as mitosis, or even
that they may be produced and detected by the DNA in the cell nucleus.
In 1974 Dr. V.P.Kazmacheyev announced that his research team in
Novosibirsk had detected intercellular communication by means of these
rays.
Proponents additionally claim that studies have shown that injured
cells will emit a higher biophoton rate than normal cells and that
organisms with illnesses will likewise emit a brighter light, which
has been interpreted as implying a sort of distress signal. These
ideas tend to support Gurwitsch's original idea that biophotons may be
important for the development of larger structures such as organs and
organisms.
However such conclusions are debatable. Injured cells are under higher
amounts of oxidative stress, which ultimately is the source of the
light, and whether this constitutes a "distress signal" or simply a
background chemical process is yet to be demonstrated. The difficulty
of teasing out the effects of any supposed biophotons amid the other
numerous chemical interactions between cells makes it difficult to
devise a testable hypothesis. Most organisms are bathed in relatively
high-intensity light that ought to swamp any signalling effect,
although biophoton signaling might manifest through temporal patterns
of distinct wavelengths or could mainly be used in deep tissues hidden
from daylight (such as the human brain, which contains photoreceptor
proteins). There remains little evidence in the scientific literature
to support the existence of such a signaling mechanism.
Photobiology
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Photobiology is the scientific study of the interactions of light
(technically, non-ionizing radiation) and living organisms. The field
includes the study of photosynthesis, photomorphogenesis, visual
processing, circadian rhythms, bioluminescence, and ultraviolet
radiation effects. The division between ionizing radiation and
nonionizing radiation is typically considered to be 10 eV, the energy
required to ionize an oxygen atom.
Light effects on circadian rhythm
----------------------------------------------------
Numerous organisms maintain inherent individual daily rhythms to
biological processes, known as circadian rhythms, that assist the
organism in maintaining functional periodicity relative to the 24-hour
day/night cycle of the earth. These rhythms are maintained by the
individual organisms, but due to variable individuality and
environmental pressures, must continually or repeatedly be reset to
synch with the natural environmental cycle. In order for this to be
accomplished, external factors must play some role in the
synchronization, or entrainment, of the internal circadian rhythm with
the external environment. Of the various factors that influence this
entrainment, light exposure to the eyes is the strongest effecter
Demonstrated effects
All of the mechanisms of light-effected entrainment are not yet fully
known, however numerous studies have demonstrated the effectiveness of
light entrainment to the day/night cycle. Studies have shown that:
The timing of exposure to light influences entrainment; as seen on the
phase response curve for light for a given species.
In diurnal species, exposure to bright light after wakening advances
the circadian rhythm, whereas exposure before sleeping delays the
rhythm.
The length of exposure influences entrainment.
Longer exposures have a greater effect than shorter exposures.
Consistent exposure has a greater effect than intermittent exposure.
In rats, constant exposure eventually disrupts the cycle to the point
that functions like memory and stress coping may be impaired.
Intensity and wavelength of light influence entrainment.
Brighter light is more effective than dim light.
Dim light can effect entrainment relative to darkness.
In humans, low intensity short wavelength (blue/violet) light may be
equally effective as high intensity white light.
Internal regulators
------------------------------
Light's effect on the circadian rhythms of all or most animals has
been well-documented. However, since circadian rhythms are internal
functions, the influence of external factors like light and an
individual's sensitivity to them can to some degree be regulated by
internal mechanisms.
In zebrafish, evidence of a negative regulation of light-dependent
gene transcription has been found. In one study, overabundance of the
enzyme catalase reduced the transcription of genes that were dependent
on light, whereas inhibition of the enzyme resulted in increased
transcription.
Another study found that a deficit of the oligopeptide angiotensin in
the brain of laboratory rats resulted in delayed adjustment to changes
in the day/night pattern.
Similarly, deficits of TrkB tyrosine kinase in mice, a receptor for
brain-derived neurotrophic factor (BDNF), result in a decrease of the
ability to entrain to shifts in the day/night cycle.
Internal conditions may thus sway the effectiveness of entrainment to
light. All mechanisms behind the process are not yet fully understood.
Other factors
---------------------
Although many researchers consider light to be the strongest cue for
entrainment, it is by no means the only factor acting on circadian
rhythms. Other factors may enhance or decrease the effectiveness of
entrainment. For instance, physical activity like exercise when
coupled with light exposure results in a somewhat stronger entrainment
response. Other factors such as music and administration of the
neurohormone melatonin have shown similar effects. Numerous other
factors affect entrainment as well. These include feeding schedules,
temperature, pharmacology, locomotor stimuli, social interaction,
sexual stimuli and stress
Photoperiodism
------------------------
In plants
Many flowering plants use a photoreceptor protein, such as phytochrome
or cryptochrome, to sense seasonal changes in night length, or
photoperiod, which they take as signals to flower. In a further
subdivision, obligate photoperiodic plants absolutely require a long
or short enough night before flowering, whereas facultative
photoperiodic plants are more likely to flower under the appropriate
light conditions, but will eventually flower regardless of night
length.
Photoperiodic flowering plants are classified as long-day plants or
short-day plants, though the regulatory mechanism is actually governed
by hours of darkness, not the length of the day.
Modern biologists believe that it is the coincidence of the active
forms of phytochrome or cryptochrome, created by light during the
daytime, with the rhythms of the circadian clock that allows plants to
measure the length of the night. Other than flowering, photoperiodism
in plants includes the growth of stems or roots during certain
seasons, or the loss of leaves.
Long-day plants
------------------------
A long-day plant requires fewer than a certain number of hours of
darkness in each 24-hour period to induce flowering. These plants
typically flower in the northern hemisphere during late spring or
early summer as days are getting longer. In the Northern Hemisphere,
the longest day of the year is on or about 21 June (solstice). After
that date, days grow shorter (i.e. nights grow longer) until 21
December (solstice). This situation is reversed in the Southern
Hemisphere (i.e. longest day is 21 December and shortest day is 21
June). In some parts of the world, however, "winter" or "summer" might
refer to rainy versus dry seasons, respectively, rather than the
coolest or warmest time of year.
Some long-day obligate plants are:
Carnation (Dianthus)
Henbane (Hyoscyamus)
Oat (Avena)
Ryegrass (Lolium)
Clover (Trifolium)
Bellflower (Campanula carpatica)
Some long-day facultative plants are:
Pea (Pisum sativum)
Barley (Hordeum vulgare)
Lettuce (Lactuca sativa)
Wheat (Triticum aestivum, spring wheat cultivars)
Turnip (Brassica rapa)
Arabidopsis thaliana (model organism)
Short-day plants
----------------------
Short-day plants flower when the night is longer than a critical
length. They cannot flower under long days or if a pulse of artificial
light is shone on the plant for several minutes during the middle of
the night; they require a consolidated period of darkness before
floral development can begin. Natural nighttime light, such as
moonlight or lightning, is not of sufficient brightness or duration to
interrupt flowering.
In general, short-day (i.e. long-night) plants flower as days grow
shorter (and nights grow longer) after 21 June in the Northern
Hemisphere, which is during summer or fall. The length of the dark
period required to induce flowering differs among species and
varieties of a species.
Photoperiod affects flowering when the shoot is induced to produce
floral buds instead of leaves and lateral buds. Note that some species
must pass through a "juvenile" period during which they cannot be
induced to flower -- common cocklebur is an example of a plant species
with a remarkably short period of juvenility and plants can be induced
to flower when quite small.
Some short-day obligate plants are:
Chrysanthemum
Coffee
Poinsettia
Strawberry
Tobacco, var. Maryland Mammouth
Common duckweed, (Lemna minor)
Cocklebur (Xanthium)
Maize - tropical cultivars only
Some short-day facultative plants are:
Hemp (Cannabis)
Cotton (Gossypium)
Rice
Sugar cane
Day-neutral plants
Day-neutral plants, such as cucumbers, roses and tomatoes, do not
initiate flowering based on photoperiodism at all; they flower
regardless of the night length. They may initiate flowering after
attaining a certain overall developmental stage or age, or in response
to alternative environmental stimuli, such as vernalization (a period
of low temperature), rather than in response to photoperiod.
In animals
Daylength, and thus knowledge of the season of the year, is vital to
many animals. A number of biological and behavioural changes are
dependent on this knowledge. Together with temperature changes,
photoperiod provokes changes in the colour of fur and feathers,
migration, entry into hibernation, sexual behaviour, and even the
resizing of sexual organs.
In mammals, for example, daylength is registered in the
suprachiasmatic nucleus (SCN), which is informed by retinal
light-sensitive ganglion cells, which are not involved in vision. The
information travels through the retinohypothalamic tract (RHT).
Birds', such as the canary, singing frequency depends on the
photoperiod. In the spring when the photoperiod increases (more
daylight), the male canary's testes grow. As the testes grow, more
androgens are secreted and song frequency increases. During autumn
when the photoperiod decreases (less daylight), the male canary's
testes regress and androgen levels dramatically drop resulting in
decreased singing frequency. Not only is singing frequency dependent
on the photoperiod but also song repertoire. The long photoperiod of
spring results in a greater song repertoire. Autumn's shorter
photoperiod results in a reduction in song repertoire. These
behavioral photoperiod changes in male canaries are caused by changes
in the song center of the brain. As the photoperiod increases so does
the high vocal center (HVC) and the robust nucleus of the
archistriatum (RA). When the photoperiod decreases these areas of the
brain regress
Chronobiology
---------------------
Chronobiology is a field of biology that examines periodic (cyclic)
phenomena in living organisms and their adaptation to solar and lunar
related rhythms. These cycles are known as biological rhythms.
"Chrono" pertains to time and "biology" pertains to the study, or
science, of life. The related terms chronomics and chronome have been
used in some cases to describe either the molecular mechanisms
involved in chronobiological phenomena or the more quantitative
aspects of chronobiology, particularly where comparison of cycles
between organisms is required.
Chronobiological studies include but are not limited to comparative
anatomy, physiology, genetics, molecular biology and behavior of
organisms within biological rhythms mechanics. Other aspects include
development, reproduction, ecology and evolution.
The variations of the timing and duration of biological activity in
living organisms occur for many essential biological processes. These
occur (a) in animals (eating, sleeping, mating, hibernating,
migration, cellular regeneration, etc.), (b) in plants (leaf
movements, photosynthetic reactions, etc.), and in microbial organisms
such as fungi and protozoa. They have even been found in bacteria,
especially among the cyanobacteria (aka blue-green algae, see
bacterial circadian rhythms). The most important rhythm in
chronobiology is the circadian rhythm, a roughly 24 hour-cycle shown
by physiological processes in all these organisms. The term circadian
comes from the Latin circa, meaning "around" and dies, "day", meaning
"approximately a day."
The circadian rhythm can further be broken down into routine cycles
during the 24-hour day:
Diurnal, which describes organisms active during daytime
Nocturnal, which describes organisms active in the night
Crepuscular, which describes animals primarily active during the dawn
and dusk (ex: white-tailed deer, some bats)
Many other important cycles are also studied, including:
Infradian rhythms, which are cycles longer than a day, such as the
annual migration or reproduction cycles found in certain animals or
the human menstrual cycle.
Ultradian rhythms, which are cycles shorter than 24 hours, such as the
90-minute REM cycle, the 4-hour nasal cycle, or the 3-hour cycle of
growth hormone production.
Tidal rhythms, commonly observed in marine life, which follow the
roughly 12-hour transition from high to low tide and back.
Gene oscillations — some genes are expressed more during certain hours
of the day than during other hours.
A circadian cycle was first observed in the 18th century in the
movement of plant leaves by the French scientist Jean-Jacques d'Ortous
de Mairan (for a description of circadian rhythms in plants by de
Mairan, Linnaeus, and Darwin see this page). In 1751 Swedish botanist
and naturalist Carolus Linnaeus (Carl von Linné) designed a floral
clock using certain species of flowering plants. By arranging the
selected species in a circular pattern, he designed a clock that
indicated the time of day by the flowers that were open at each given
hour. For example, among members of the daisy family, he used the
hawk's beard plant which opened its flowers at 6:30 AM and the hawkbit
which did not open its flowers until 7 AM.
The 1960 symposium at Cold Spring Harbor Laboratory laid the
groundwork for the field of chronobiology.
It was also in 1960 that Patricia DeCoursey invented the phase
response curve, since one of the major tools used in the field.
Franz Halberg of the University of Minnesota, who coined the word
circadian, is widely considered the "father of American
chronobiology". However, it was Colin Pittendrigh and not Halberg who
was elected to lead the Society for Research in Biological Rhythms in
the 1970s. Halberg wanted more emphasis on the human and medical
issues while Pittendrigh had his background more in evolution and
ecology. With Pittendrigh as leader, the Society members did basic
research on all types of organisms, plants as well as animals. More
recently it has been difficult to get funding for such research on any
other organisms than mice, rats, humans[4][5] and fruit flies.
[edit] Recent developments
More recently, light therapy and melatonin administration have been
explored by Dr. Alfred J. Lewy (OHSU), Dr. Josephine Arendt
(University of Surrey, UK) and other researchers as a means to reset
animal and human circadian rhythms. Humans can be morning people or
evening people; these variations are called chronotypes for which
there are various assessment tools and biological markers.
In the second half of 20th century, substantial contributions and
formalizations have been made by Europeans such as Jürgen Aschoff and
Colin Pittendrigh, who pursued different but complementary views on
the phenomenon of entrainment of the circadian system by light
(parametric, continuous, tonic, gradual vs. nonparametric, discrete,
phasic, instantaneous, respectively; see this historical article,
subscription required).
There is also a food-entrainable biological clock, which is not
confined to the suprachiasmatic nucleus. The location of this clock
has been disputed. Working with mice, however, Fuller et al. concluded
that the food-entrainable clock seems to be located in the dorsomedial
hypothalamus. During restricted feeding, it takes over control of such
functions as activity timing, increasing the chances of the animal
successfully locating food resources.
Other fields
Chronobiology is an interdisciplinary field of investigation. It
interacts with medical and other research fields such as sleep
medicine, endocrinology, geriatrics, sports medicine, space medicine
and photoperiodism
The unsubstantiated theory of biorhythms, which is said to describe a
set of cyclic variations in human behaviour based on physiological and
emotional cycles, is not a part of chronobiology
Florigen
-------------
Florigen (or flowering hormone) is the term used to describe the
hypothesized hormone-like molecules responsible for controlling and/or
triggering flowering in plants. Florigen is produced in the leaves and
acts in the shoot apical meristem of buds and growing tips. It is
known to be graft-transmissible and even functions between species.
However despite having been sought since the 1930s, the exact nature
of florigen is still a mystery
Mechanism
--------------------
Central to the hunt for florigen is an understanding of how plants use
seasonal changes in day length to mediate flowering, a mechanism known
as photoperiodism. Plants which exhibit photoperiodism may be either
'short day' or 'long day' plants, which in order to flower require
short days or long days respectively. Although plants in fact
determine day length from night length.
The current model suggests the involvement of multiple different
factors. Research into florigen is predominately centred around the
model organism and long day plant, Arabidopsis thaliana. Whilst much
of the florigen pathways appear to be well conserved in other studied
species, variations do exist. The mechanism may be broken down into
three stages: photoperiod-regulated Initiation, signal Translocation
via the phloem, and induction of Flowering at the shoot apical
meristem.
Initiation
--------------
In Arabidopsis, the signal is initiated by the production of messenger
RNA (mRNA) coding a transcription factor called CONSTANS (CO). CO mRNA
is produced approximately 12 hours after dawn, a cycle regulated by
the plant's biological clock. This mRNA is then translated into CO
protein. However CO protein is stable only in light, so levels stay
low throughout short days and are only able to peak at dusk during
long days when there is still a little light. CO protein promotes
transcription of another gene called Flowering Locus T (FT). By this
mechanism, CO protein may only reach levels capable of promoting FT
transcription when exposed to long days. Hence the transmission of
florigen, and so the induction of flowering, relies on a comparison
between the plant's perception of day/night and its own internal
biological clock.
Translocation
The FT protein resulting from the short period of CO transcription
factor activity is then transported via the phloem to the shoot apical
meristem.
Flowering
At the shoot apical meristem the FT protein is thought to interact
with another transcription factor, FD protein, to activate floral
identity genes, thus inducing flowering.[7][8] Specifically, arrival
of FT at the shoot apical meristem and formation of this FT/FD
heterodimer is followed by the increased expression of: SUPPRESSOR OF
OVEREXPRESSION OF CONSTANS 1 (SOC1),[9] LEAFY (LFY),[10] APETALA 1
(AP1),[7] SEPALLATA 3 (SEP3) and FRUITFUL (FUL).[11]
Research history
-----------------------------
Florigen was first described by Russian plant physiologist Mikhail
Chailakhyan in 1937, who demonstrated that floral induction can be
transmitted through a graft from an induced plant to one that has not
been induced to flower. Anton Lang showed that several long-day plants
and biennials could be made to flower by treatment with gibberellin,
when grown under a non-flower-inducing (or non-inducing) photoperiod.
This led to the suggestion that florigen may be made up of two classes
of flowering hormones: Gibberellins and Anthesins. It was later
postulated that during non-inducing photoperiods, long-day plants
produce anthesin, but no gibberellin while short-day plants produce
gibberellin but no anthesin. However, these findings did not account
for the fact that short-day plants grown under non-inducing conditions
(thus producing gibberellin) will not cause flowering of grafted
long-day plants that are also under noninductive conditions (thus
producing anthesin).
Problems with isolating florigen and the inconsistent results acquired
led to the suggestion that florigen does not exist; rather, a
particular ratio of other hormones must be achieved for the plant to
flower. However more recent findings indicate that florigen does exist
and is produced, or at least activated, in the leaves of the plant and
that this signal is then transported via the phloem to the growing tip
at the shoot apical meristem where the signal acts by inducing
flowering.
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