U.S. patent application number 13/429014 was filed with the patent office on 2012-10-04 for composition and method for stress mitigation in plants.
This patent application is currently assigned to STOLLER ENTERPRISES, INC.. Invention is credited to Albert Liptay, Ronald Salzman, Jerry Stoller.
Application Number | 20120252673 13/429014 |
Document ID | / |
Family ID | 46927999 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120252673 |
Kind Code |
A1 |
Stoller; Jerry ; et
al. |
October 4, 2012 |
COMPOSITION AND METHOD FOR STRESS MITIGATION IN PLANTS
Abstract
A composition and method to mitigate plant autophagy and/or
apoptosis of newly developing cells in plants grown under
environmentally stressful growing conditions. Exogenous application
of a cytokinin, preferably kinetin, to the foliage of plants has
been discovered to overcome, or at least mitigate, autophagy when
applied during or just prior to flowering. Several provided
examples show that, in laboratory and field experiments, exogenous
foliar application of cytokinin to the leaves and flowers of plants
lessened cytokinin deficiencies in plant tissues grown in high
temperatures, thereby mitigating autophagy and apoptosis and
greatly enhancing seed/crop production. The application of low
concentrations of potassium together with the cytokinin appears to
provide a synergistic effect by amplifying the effect of the
cytokinin to lessen autophagy and increase crop productivity.
Inventors: |
Stoller; Jerry; (Houston,
TX) ; Liptay; Albert; (Houston, TX) ; Salzman;
Ronald; (College Station, TX) |
Assignee: |
STOLLER ENTERPRISES, INC.
|
Family ID: |
46927999 |
Appl. No.: |
13/429014 |
Filed: |
March 23, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61469044 |
Mar 29, 2011 |
|
|
|
Current U.S.
Class: |
504/124 ;
504/241 |
Current CPC
Class: |
A01N 43/90 20130101;
C05F 11/10 20130101; A01N 47/36 20130101; A01N 43/90 20130101; A01N
59/00 20130101; A01N 2300/00 20130101; A01N 59/00 20130101 |
Class at
Publication: |
504/124 ;
504/241 |
International
Class: |
A01N 43/90 20060101
A01N043/90; A01P 21/00 20060101 A01P021/00; A01N 59/00 20060101
A01N059/00 |
Claims
1. A method of mitigating plant autophagy in plants grown under a
high stress environmental condition, said method comprising the
steps of: readying a plant hormone for application to plants, said
plant hormone being primarily cytokinin, and applying said plant
hormone in an aqueous solution to the foliage or flowers of said
plants during or just prior to flowering, said aqueous solution
having a concentration of between about 0.01 wt % to about 0.1 wt %
cytokinin, said aqueous solution applied to said plants at a rate
of about 1/4 pint to about 4 pints per acre.
2. The method of claim 1 wherein, said high stress environmental
condition is a daytime temperature of greater than about 30 degrees
Celsius.
3. The method of claim 2 wherein, said daytime temperature of
greater than 30 degrees Celsius occurs during or just prior to
flowering.
4. The method of claim 1 further comprising the step of, applying
potassium to the foliage or flowers of said plants at the rate of
between about 1/4 lb. to about 2 lbs. potassium per acre.
5. A method of farming comprising the steps of: readying an
autophagy-inhibiting agent for application to growing plants, said
autophagy inhibiting agent consisting of a plant hormone, said
plant hormone including a cytokinin, readying a potassium salt for
application to said growing plants, and applying said
autophagy-inhibiting agent and said potassium salt in an aqueous
solution to the foliage or flowers of said growing plants during or
just prior to flowering, said aqueous solution applied to said
growing plants such that between about 0.09 grams to about 0.76
grams of cytokinin are applied per acre of growing plants.
6. The method of fanning of claim 5 wherein, said potassium salt is
applied to the foliage or flowers of said growing plants at the
rate of about 1/4 lb. to about 2 lbs. potassium salt per acre.
7. A method of growing plants comprising the steps of: readying a
plant hormone and potassium for application to foliage or flowers
of plants that grow in an average daytime temperature above about
20 degrees Celsius, said plant hormone having cytokinin as a
majority component, and applying an aqueous solution of said plant
hormone and said potassium to the foliage or flowers of said plants
during or just prior to flowering, said cytokinin applied to said
plants at a rate between about 0.09 grams per acre to about 0.76
grams per acre.
8. The method of claim 7 wherein, said potassium is applied to the
foliage or flowers of said plants at a rate of between about 1/4
lb. to about 2 lbs. per acre.
9. The method of claim 7 wherein, said average daytime temperature
above about 20 degrees Celsius occurs during or just prior to
flowering.
10. The method of claim 7 wherein, said average daytime temperature
exceeds about 30 degrees Celsius.
11. A composition for mitigating environmental stress in growing
plants, said composition comprising: a plant hormone including
primarily a cytokinin, said cytokinin being present in an aqueous
solution of said composition at a concentration of between about
0.1 ppm to about 3.4 ppm cytokinin, said composition being an
amount effective to lessen plant autophagy under an average daytime
growing temperature above 30 degrees Celsius.
12. The composition of claim 11 further comprising, a potassium
salt present in said composition at a concentration of between
about 500 ppm to about 4,000 ppm potassium salt.
13. A composition for lessening environmental stress in growing
plants, said composition comprising: a plant hormone having
cytokinin as a majority component, said cytokinin being present in
an aqueous solution of said composition at a concentration such
that between about 0.09 grams to about 0.76 grams of cytokinin may
be applied per acre of said growing plants when said composition is
so applied, said composition being an amount effective to lessen
plant autophagy under an average daytime growing temperature above
30 degrees Celsius and a potassium salt being present in said
aqueous solution of said composition at a concentration such that
between about 1/4 lb. to about 2 lbs. of potassium salt may be
applied per acre of said growing plants when said composition is so
applied.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a method and composition
for mitigating plant autophagy or the degradation of older plant
cells to supply nutrients to deficient newly-forming plant cells,
which can occur during development (e.g., flowering) of new plant
cells under stressful conditions, such as high temperatures.
Moreover, this invention relates to the enhanced development of
seeds, and consequently, the increased yield of harvestable grains
from plants, including crop plants, that experience environmentally
stressful growing conditions during development and growth.
[0003] 2. Description of the Related Art
[0004] Traditionally, mineral fertilizers have been predominately
applied to growing crop plants. Difficulties arise, however, when
external stresses impede successful plant development, especially
of grain or seed crops. Physical stresses, such as those inflicted
by environmental temperatures being either too low or too high, and
in particular high temperatures, are especially problematic.
Moreover, the state-of-the-art agronomic practice does not employ
plant growth regulators to overcome a plant's difficulty, due to
such stresses, in producing sufficient amounts of nutrients, e.g.,
sugars, to prevent autophagy (i.e., cannibalization of
previously-formed plants cells by newly-forming cells to compensate
for a dearth of cell nutrients). It is well known that mineral
fertilizers provide sixteen minerals that are necessary for crop
growth and development; however, these minerals are not signaling
molecules to effect gene expression. Signaling molecules, such as
plant growth regulators, are known to enhance crop productivity
through the expression of certain genes. Furthermore, much research
has been conducted into the use of plant growth regulators and
their effects on plant growth and development. However, until
disclosure of the invention herein, it has not been known that the
application of certain "signaling molecules" improves plant
productivity by mitigating plant autophagy caused by environmental
stresses, such as high growing temperatures.
[0005] Considering the sheer amount of research into techniques and
compositions to improve food production as well as the continual
need for greater food production to feed an exponential human
population growth, there is a long felt and unfulfilled need for
improved methods and compositions to improve plant productivities,
especially in view of higher environmental temperatures and other
harsher growing conditions.
[0006] 3. Identification of Objects of the Invention
[0007] An object of the invention is to accomplish one or more of
the following:
[0008] Provide a method and composition to enhance the productivity
and growth of crop plants;
[0009] Provide a method and composition to enhance the productivity
and growth of crop plants grown under harsh environmental
stresses;
[0010] Provide a method and composition to enhance the productivity
and growth of plants grown under high temperature conditions;
[0011] Provide a method and composition to increase the synthesis
of nutrients by plants; and
[0012] Provide a method and composition to mitigate plant autophagy
and/or apoptosis;
[0013] Other objects, features, and advantages of the invention
will be apparent from the following specification and drawings to
one skilled in the art.
SUMMARY OF THE INVENTION
[0014] The objects identified above, along with other features and
advantages of the invention are incorporated into a method and
composition for growing plants, especially crop plants, to be more
productive and/or resilient to stressful growing conditions, such
as high temperature. When growing temperatures are too high, the
development of flowers and subsequent embryos (seeds) is known to
be compromised, with the concomitant result that productivity of
crop grains or other types of agronomic harvest is impaired and
crop yields are drastically decreased. Under extreme growing
conditions, such as high temperatures, plants experience an
inability to produce the nutrients, such as sugars, necessary for
conducting normal anabolic processes (i.e., flower and embryo/seed
development). To compensate for this dearth of nutrients, plants
growing under these stress conditions typically undergo autophagy,
or self-cannibalization, to secure the necessary nutrients.
[0015] Exogenous application to the plant canopy (i.e. leaves and
flowers) of the plant growth regulator/hormone cytokinin has been
discovered to prevent such autophagy by inducing the necessary
production of sufficient nutrients (i.e., sugars) for the growth of
new plant cells (i.e., successful and complete seed development).
It is thought that genes controlling for increased levels of
photosynthates (i.e., plant sugar/energy producers) are triggered
by exogenous application of cytokinin. Additionally, the
application of low concentrations of potassium along with the
cytokinin has been found to substantially increase the effect of
the cytokinin. Such results are unexpected with such low potassium
concentrations, because they differ from the physiological effects
normally attributed to higher application rates of fertilizer-grade
potassium. It is thought that the application of low concentrations
of potassium act much like other signaling molecules (e.g.,
hormones) in stimulating transcription of particular genes, such as
the genes that express cytokinin effects. The synergy from the
application of low concentrations of potassium and cytokinin to
growing plants may also be realized under lower stress growing
conditions.
[0016] The disclosed composition and its method of application
represents a practical approach to mitigating plant autophagy, and
any ensuing apoptosis, that results from stressful plant growing
conditions, such as high temperatures. The method preferably
includes the application of a plant hormone, primarily a cytokinin,
to the foliage and/or flowers of plants at or about the time of
plant flowering (e.g., during meiosis and when pollen is about to
enter dehiscence). This autophagy-inhibiting agent is preferably
the cytokinin, kinetin, however, other forms of cytokinin may be
used singularly or in combination, such as zeatin, various forms of
zeatin, N6-benzyl adenine, N6-(delta-2-isopentyl) adenine,
1,3-diphenyl urea, thidiazuron, CPPU (forchlorfenuron) or other
chemical formulations with cytokinin-like activity. Preferably, but
optionally, a low concentration of potassium is also applied
together with the plant hormone to enhance the effects of the plant
hormone as previously described.
[0017] In a first step, the cytokinin plant hormone is readied for
application to the plants to be treated. The cytokinin plant
hormone is preferably applied to the plants as an aqueous solution.
Therefore, readying the cytokinin plant hormone may include one or
more of the following activities: diluting the cytokinin plant
hormone in sufficient water to create the desired concentration of
cytokinin in the applied mixture/composition, adding low
concentrations of potassium to the cytokinin plant hormone
mixture/composition to enhance the effects of the applied
cytokinin, loading the cytokinin plant hormone with or without
potassium (or an aqueous mixture thereof) into a sprayer or tank
for subsequent application to the plants to be treated, calibrating
the sprayer or dosing applicator to meter the desired amount of the
cytokinin plant hormone mixture to the plants to be treated and
transporting the cytokinin plant hormone with or without potassium
(or an aqueous mixture thereof) to the location of the plants to be
treated.
[0018] Preferably, the cytokinin concentration in an undiluted
aqueous solution ranges from about 0.01% to about 0.10%. A
commercially-available, undiluted cytokinin solution, X-Cyte (a
product of Stoller USA, Houston, Tex.), supplies the preferred
cytokinin concentration of about 0.04%. At the preferred cytokinin
concentration, the undiluted aqueous solution of cytokinin is
applied in a second step to plants to be treated at the rate of
between about 1/4 to 4 pints solution per acre of growing plants
and more preferably between 1 to 2 pints solution per acre of
growing plants. Such application equates to a rate of between about
0.09 to about 0.76 grams cytokinin per acre of growing plants
(diluted in 60 gallons of water per acre), and more preferably, at
a rate of between about 0.19 to about 0.38 grams cytokinin per acre
of growing plants (diluted in 60 gallons of water per acre).
Potassium, if applied with the cytokinin, is preferably applied at
very low concentrations. The potassium application rates are
preferably between about 1/4 lb. to about 2 lbs. per acre, more
preferably between about 1/2 lb. to about 11/2 lbs. per acre, and
most preferably about 1 lb. per acre.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] By way of illustration and not limitation, the invention is
described in detail hereinafter on the basis of the accompanying
figures, in which:
[0020] FIG. 1 is a histogram of experimental results testing
whether impaired seed/silique development under high temperature
growth conditions is caused by a nutrient/sugar insufficiency,
which may incite apoptosis of newly-forming plant cells via
autophagy; and
[0021] FIG. 2 is a histogram of experimental data that verifies the
results obtained in FIG. 1, namely that high temperature yield
reduction, caused by autophagy, is mainly due to an insufficiency
of the plant growth regulator/hormone, cytokinin.
DESCRIPTION OF THE PREFERRED IMPLEMENTATIONS OF THE INVENTION
[0022] A preferred implementation of the invention addresses one or
more of the deficiencies of the prior art and incorporates at least
one of the objects previously identified. The invention employs a
plant growth regulator, preferably a cytokinin, which when
appropriately applied to plants has been discovered to enhance the
synthesis and transfer of sufficient nutrients, such as sugars, for
the growth and development of the reproductive parts (e.g., in
particular, the pollen) of plants grown under stressful conditions,
such as high temperatures. For the purposes of this invention, high
growing temperatures include growing temperatures above about 25
degrees Celsius (77 degrees Fahrenheit), but more commonly growing
temperatures above about 30 degrees Celsius (86 degrees
Fahrenheit). Even a temperature greater than about 20 degrees
Celsius (68 degrees Fahrenheit) may be considered a "high"
temperature, depending on the plant type (e.g., wheat barley and
rye) and/or locality (e.g., distance from the earth's poles). Such
high temperatures have been found to compromise crop plant
productivity. This is thought to be the result of the reduction of
cytokinin plant hormones in the plant due to the high
temperatures.
[0023] A reduction in the level of cytokinin in the plant tissues
incites autophagy self-cannibalization of healthy plant tissues to
provide the required nutrients for reproductive development. The
stress of autophagy can compromise seed formation (Cheikh et al.
1994), structural strength and/or physical integrity of the
reproductive organs (and thus successful egg fertilization) (Liptay
et al. 1994), cell arrangement and organ functionality (Lolle et
al. 1998), cell replication (Takahshi et al. 2008) and cell growth
(Szekeres et al. 1996). These stress effects are due to autophagy
of pre-formed tissues in the various processes of plant growth and
development mentioned previously. Furthermore, this autophagy
results in apoptosis of potential crop products, thereby
significantly reducing crop yield.
[0024] Exogenous applications of cytokinin to the flowers and
leaves (i.e., foliage) of plants provides the spatially-required,
growth regulator signaling effect needed for enhanced synthesis of
nutrients/sugars for use by tender new cells. Enhancement of
nutrient synthesis, via cytokinin application, is believed to
result in a more complete development of the biological tissues for
plant reproduction. Specifically, the availability of an adequate
supply of nutrients/energy leads to the successful development of
the male sperm, including the various tissues and biological
signals responsible for its development. An adequate energy source
also aids in the various stages of development of the pollen in
which the sperm are protected by encasement. Also, adequate
nutrients/energy are available to assist the male sperm in its
journey from the pollen grain, through the developing pollen tube
and into the female ovary for fertilization of the egg. Thus,
cytokinin application results in the successful formation of seed
embryos and associated tissues of the crop plant, thereby
overcoming autophagy and any resultant apoptosis.
[0025] Additionally, the application of low concentrations of
potassium along with the cytokinin has been found to substantially
increase the effect of the cytokinin on plant tissues. Such results
are unexpected and differ from the physiological effects normally
attributed to higher application rates of typical fertilizer-grade
potassium. The physiological effects of higher applied potassium
concentrations include: maintaining turgidity in the plants and
thus ensuring a water supply, neutralizing anions helping to
stabilize pH of the cytoplasm, and general metabolic processes. To
induce these physiological effects, the concentration of applied
potassium must be on the order of typical fertilizers. The low
concentrations of potassium, disclosed herein, employed for
signaling effect are at least ten percent lower than typical
potassium fertilizer applications, such as those described in U.S.
Pat. No. 4,581,056 issued to Nooden et al. or in A. A. Csizinszky,
Foliar and Soil-Applied Biostimulant Studies with Microirrigated
Pepper and Tomato, 103 PROC. FLA. STATE HORT. SOC. 113-17 (1990).
It is thought that potassium, applied in low concentrations, acts
much like other signaling molecules (e.g., hormones) in aiding
transcription of particular genes, such as the genes that are
expressed in response to applied cytokinin. Potassium, if applied
with the cytokinin, is preferably applied at very low
concentrations between about 1/4 lb. to about 2 lbs. per acre, more
preferably between about 1/2 lb. to about 11/2 lbs. per acre, and
most preferably about 1 lb. per acre. The signaling effect of the
potassium has been found to be increasingly diminished for
potassium application rates greater than about 2 lbs. per acre.
[0026] A preferred implementation of the invention facilitates the
successful synthesis of nutrients/sugars, such that these
nutrients/sugars (i.e., chemical energy) may be transferred to the
developing male plant organs. The method preferably includes the
application of a plant hormone, primarily a cytokinin, to the
foliage and/or flowers of plants at or about the time of plant
flowering. The period of potential effectiveness of cytokinin
application may range from several weeks prior to flower emergence,
up to and including flower emergence, pollination, and during
subsequent embryo development. A preferred time is during the
process of meiosis, when pollen mother cells my fail to
differentiate, or fail to divide. This time of meiosis occurs in
dicot plants during an interval after flower bud differentiation,
but before the flowers open. In monocot plants, such as grains, it
corresponds approximately to the "early boot" stage (Feekes stage
10.0) in grain development. Another preferred time is during pollen
release from the tapetum and pollen sacs, when pollen is about to
enter dehiscence (or shed). In dicot plants, this generally falls
within the period ranging from immediately before the opening of
the flower up until the flower dies and falls off the plant. In
monocot plants, pollen release corresponds approximately to Feekes
stage (10.5.1) in grain development. The application of cytokinin
after flowering may also enhance the development of the embryo
under high temperature growing conditions and thereby increase
yield.
[0027] The autophagy-inhibiting agent is preferably the cytokinin,
kinetin, however, other forms of cytokinin may be used singularly
or in combination, such as zeatin, various forms of zeatin,
N6-benzyl adenine, N6-(delta-2-isopentyl)adenine, 1,3-diphenyl
urea, thidiazuron, CPPU (forchlorfenuron) or other chemical
formulations with cytokinin-like activity. Preferably, but
optionally, a low concentration of potassium is also applied
together with the plant hormones to enhance the effects of the
plant hormone, cytokinin.
[0028] In a first step, the cytokinin plant hormone is readied for
application to the plants to be treated. The cytokinin plant
hormone is preferably applied to the plants as an aqueous solution.
Application of agricultural chemicals may be accomplished in any of
several ways well known to those skilled in the art, including but
not limited to, spraying, drip lines, side dressing, etc.
Therefore, readying the cytokinin plant hormone may include one or
more of the following activities: diluting the cytokinin plant
hormone in sufficient water to create the desired concentration of
cytokinin in the applied mixture/composition, adding a low
concentration of potassium to the cytokinin plant hormone
mixture/composition to enhance the effect of the applied cytokinin,
loading the cytokinin plant hormone with or with out potassium (or
an aqueous mixture thereof) into a sprayer or tank for subsequent
application to the plants to be treated, calibrating the sprayer or
dosing applicator to meter the desired amount of the cytokinin
plant hormone to the plants to be treated and transporting the
cytokinin plant hormone with or without potassium (or an aqueous
mixture thereof) to the location of the plants to be treated.
[0029] Preferably, the cytokinin concentration in an undiluted
aqueous solution ranges from about 0.01% to about 0.10%. A
commercially-available, undiluted cytokinin product, X-Cyte (a
product of Stoller USA, Houston, Tex.), supplies the preferred
cytokinin concentration of about 0.04%. At the preferred cytokinin
concentration, the undiluted aqueous solution of cytokinin is
applied in a second step to plants to be treated at the rate of
between about 1/4 to 4 pints solution per acre of growing plants
and more preferably between 1 to 2 pints solution per acre of
growing plants. Such application equates to a rate of between about
0.09 grams to about 0.76 grams of cytokinin per acre of growing
plants (diluted in 60 gallons of water per acre for a
sprayed/applied solution), and more preferably, at a rate of
between about 0.19 to about 0.38 grams cytokinin per acre of
growing plants (diluted in 60 gallons of water per acre for a
sprayed/applied solution), depending on the specific plant/crop
species. Thus, as disclosed above, the amount of cytokinin applied
to the growing plants (1 to 2 pints of undiluted cytokinin solution
per acre, which is equivalent to 0.1 ppm to 1.66 ppm cytokinin of
the sprayed/applied solution per acre) is much lower than previous
cytokinin applications to growing plants. In fact, the preferred
application rates are more than ten fold lower than other reported
ranges of cytokinin application, which are from about 20 ppm to
about 400 ppm as suggested by N. G. Denny, User Guide of Plant
Growth Regulators. If the duration of flower development is
lengthy, the application may need to be repeated for the newly
developing flowers.
[0030] Potassium, if applied together with the cytokinin, is also
preferably applied at low concentrations. (Alternatively, the
potassium may be applied prior to or after a separate application
of cytokinin. However, such separate applications are not optimal,
because they are more energy and time intensive.) The potassium is
preferably applied as a potassium salt, such as that found in
potash, however other forms of potassium known to those skilled in
the art may be equally employed. The potassium application rates
are preferably between about 1/4 lb. to about 2 lbs. per acre
(equivalent to about 500 ppm to about 4,000 ppm potassium of the
sprayed solution per acre), more preferably between about 1/2 lb.
to about 11/2 lbs. per acre, and most preferably about 1 lb. per
acre. The synergistic effects of applying low concentrations of
cytokinin along with low concentrations of potassium to growing
plants may not be limited to high stress growing conditions but may
also be realized under lower stress growing conditions.
[0031] Preferred implementations of the invention are further
described in the following several examples. However, these
examples are not meant in any way, and should not be interpreted,
to limit the scope of the invention disclosed herein.
Example 1
[0032] Experiments were conducted to determine the extent to which
the plant growth regulator, cytokinin, when appropriately applied
to plants growing in high temperature environments, enhanced sugar
levels and increased the transfer of sugars to energy deficient
portions of the plant. These experiments were also designed to
determine whether the plant tissues under high temperature stress
suffered from one or both of two potential problems: First, whether
under high temperature stress, there is a deficiency of cytokinin
in the plant tissue. Second, whether under high temperature stress,
there is degradation of the cytokinin (which is a normal process to
regulate the balance of plant growth regulators in plant tissues,
in this case by reducing the amount of active cytokinin in the
plant tissue).
[0033] The data from these experiments, as shown in FIGS. 1 and 2,
clearly indicate that the problem suffered by plants subjected to
high temperature stresses during their flowering phase is an
inadequacy of cytokinin in the reproductive tissues of the plants.
The results further show that appropriate, exogenous cytokinin
application, as disclosed herein, increases plant development and
crop yields in high temperature growing environments (i.e.,
increases the number and quality of seeds that are properly
developed, thus increasing yield at harvest). FIG. 1 is a histogram
of experimental results testing whether impaired seed/silique
development under high temperature growth conditions is caused by a
nutrient/sugar insufficiency, which may incite apoptosis of
newly-forming plant cells by autophagy and FIG. 2 is a histogram of
experimental data that verifies the results obtained in FIG. 1,
namely that high temperature yield reduction, caused by autophagy,
is mainly due to an insufficiency of the plant growth
regulator/hormone, cytokinin.
[0034] These experiments employed the model crop plant, Arabidopsis
thaliana, whose genome was mapped as early as the year 2000. To
ensure uniformity, the tested plants were selected such that they
were in the beginning stages of flowering and had balanced numbers
of flowers across groups. The control agent as well as all tested
agents were applied in a water solution containing 0.01%
Silwet.RTM. super spreader (obtained from General Electric) to the
leaves and flowers (i.e., foliage) of the tested plants. As shown
in FIG. 1, a control agent (Ctl) consisting of an aqueous solution
of 0.01% Silwet.RTM. super spreader was applied to a control plant
group. A second tested agent consisting of
N-(2-chloro-pyridin-4-yl)-N-phenyl-urea (CPPU) at 100 .mu.g/1 (0.1
ppm) was applied to a second plant grouping to test whether the
difficulty in seed formation is due to cytokinin insufficiency or
overactive enzymes that break down cytokinin in the plant. The
third and fourth agents tested consisted of 6-benzyl adenine (6-BA)
and kinetin (KIN)--both cytokinins--each applied at the rate of 100
.mu.g/l (0.1 ppm). Finally, the fifth and sixth agents tested
consisted of sucrose sugars applied in solutions of 20 mM (SUC 20)
and 100 mM (SUC100), respectively, applied as readily-available
energy sources.
[0035] Aqueous solutions of the tested agents prepared to the
stated concentrations/doses were sprayed onto test groups of
flowers and leaves (i.e., foliage) of Arabidopsis thaliana until
runoff at one day prior to heat exposure and again at four days
after the beginning of heat exposure. The total duration of heat
exposure was fourteen (14) days. The growing temperatures were
maintained at between 33-36 degrees Celsius during sixteen (16)
hour days, and at about 25 degrees Celsius during eight (8) hour
nights. The experiments were conducted on poly(methyl
methacrylate)-enclosed shelves, i.e., Plexiglass.RTM.-enclosed
shelves, using four dual fluorescent lamps and a
thermostat-controlled exhaust fan. The seed pods (i.e. siliques),
filled with developed seeds (siliques>7 mm long and/or >1 mm
wide and/or bearing seeds), were counted just prior to the
beginning of the experiment, and again after fourteen (14) days of
heat exposure treatments.
[0036] As shown in FIG. 1, the plant growth regulator, cytokinin,
can mitigate the sugar deficiency in the plant tissues caused by
high growing temperatures, thus preventing autophagy. This result
is indicated by the increased number of seeds (i.e., siliques) in
the cytokinin tested agents 6-benzyl adenine (6-BA) and kinetin
(KIN). The slightly negative results encountered with the
N-(2-chloro-pyridin-4-yl)-N-phenyl-urea (CPPU) tested agent (i.e.,
a cytokinin oxidase inhibitor) combined with the positive results
encountered with the cytokinin tested agents clearly indicate that
the problem of high temperature induced autophagy is due to a
cytokinin insufficiency (i.e., lack of energy synthesis for the
newly forming cells). It should be noted that the two sucrose
tested agents also alleviated the sugar/photosynthate deficiency
thereby preventing plant autophagy. However, sucrose testing agents
provide expensive, temporary relief, because the sucrose breaks
down rapidly in situ.
[0037] FIG. 2 presents an additional set of experimental results
that reinforce the results obtained for the previous experiment
(FIG. 1). The second experiment was conducted in the same manner
and using the same control and tested agent concentrations as the
first experiment, with the exception of CPPU application. Thus, the
respective aqueous solutions as used in the first experiment, with
the exception of CPPU, were sprayed onto test groups of Arabidopsis
thaliana foliage until runoff at one day prior to heat exposure and
again at four days after the beginning of heat exposure. The total
duration of heat exposure was fourteen (14) days. The growing
temperatures were maintained at between 33-36 degrees Celsius
during sixteen (16) hour days, and at about 25 degrees Celsius
during eight (8) hour nights. The experiments were conducted on
poly(methyl methacrylate)-enclosed shelves, i.e.,
Plexiglass.RTM.-enclosed shelves, using four dual fluorescent lamps
and a thermostat-controlled exhaust fan. The seed pods (i.e.
siliques), filled with developed seeds (siliques >7 mm long
and/or >1 mm wide and/or bearing seeds), were counted just prior
to the beginning of the experiment, and again after fourteen (14)
days of heat exposure treatments. The results of the second
experiment may be similarly interpreted as the results of the first
experiment, thereby confirming that the plant growth regulator,
cytokinin, can mitigate the sugar deficiency in the plant tissues
caused by high growing temperatures, thus reducing autophagy.
Example 2
[0038] In this example, the effect of the plant growth regulator
cytokinin, specifically kinetin, applied at the beginning of
flowering and two to four weeks thereafter to field-grown beans
(i.e., lima beans) in Gustine, Calif. was observed. Growing
temperatures up to approximately 35 degrees Celsius were recorded.
Table 2 (below) provides the results of this replicated, randomized
experiment. The lima bean yields were increased significantly
(i.e., less seeds succumbed to autophagy and seed death or
collapse) when the aqueous solution of kinetin was applied just
prior to flowering to the lima bean foliage at either a rate of one
pint per acre or two pints per acre. The difference of "t" test of
5% is significant.
TABLE-US-00001 TABLE Crop Yield for Kinetin Solution Application at
Flowering for Rates of 0 pt/acre, 1/2 pt/acre, 1 pt/acre and 2
pt/acre Lima Bean Yield Gustine, CA Year 2010 Average Average
Average Average Yield Yield Yield Yield Average (lb/plot) (lb/plot)
(lb/plot) (lb/plot) X-Cyte pt/acre 0 0.5 1 2 Average yield
(lb/plot) 6.86 6.915 7.845 8.11375 t test vs. control 0.416532
0.000115 0.000307 t test vs. 1/2 pt/acre 0.003132 0.006917 t test
vs. 1 pt/acre 0.09629 rep 1 7.13 6.47 8.13 8.61 rep 2 6.84 8.34
8.02 8.02 rep 3 6.59 7.11 7.65 7.83 rep 4 6.8 6.68 8.07 8.37 rep 5
7.17 6.45 7.38 8.51 rep 6 7 7.17 7.55 6.85 rep 7 6.7 6.49 7.91 8.53
rep 8 6.65 6.61 8.05 8.19
Example 3
[0039] In this example, the effect of the plant growth
regulator/hormone, cytokinin, applied together with low
concentrations of potassium, was observed. The cytokinin that was
field-applied was X-Cyte, as previously disclosed. In these
unreplicated field trials, conducted in Ohio over a three year
period, potassium at 1/2 lb. to 1 lb. per acre and cytokinin at 1
pint per acre were applied to field corn. The average increase in
yield attained by applying potassium, in addition to cytokinin, was
approximately fifteen (15) bushels per acre.
[0040] The Abstract of the disclosure is written solely for
providing the United States Patent and Trademark Office and the
public at large with a means by which to determine quickly from a
cursory inspection the nature and gist of the technical disclosure,
and it represents one preferred implementation and is not
indicative of the nature of the invention as a whole.
[0041] While some implementations of the invention have been
illustrated in detail, the invention is not limited to the
implementations shown; modifications and adaptations of the
disclosed implementations may occur to those skilled in the art.
Such modifications and adaptations are in the spirit and scope of
the invention as set forth in the claims hereinafter:
* * * * *