JP6997427B2 - Function control agent for potassium ion transporter of plants and method of growing plants - Google Patents

Description

The present invention relates to a function control agent for a potassium ion transporter (channel tonrance porter pump) of a plant and a method for growing a plant to which the function control agent is applied. More specifically, the present invention relates to a function control agent for a potassium ion transporter of a plant composed of a catechin compound having a specific chemical structure, and a method for growing a modified plant body to which the control agent is applied to the plant.

Plants take in carbon dioxide (CO ₂ ) in the air from the stomata in the leaves and stems, and use CO ₂ as a nutrient for the carbon source (C source) by photosynthesis. Nitrogen (N), phosphorus (P), iron (Fe), sulfur (S), magnesium (Mg), zinc (Zn), potassium (K), calcium (Ca), chlorine (Cl), silicon (Si), Inorganic nutrients such as molybdenum (Mo) and boron (B) are absorbed from the roots. This absorption is contributed by the transpiration flow generated by the opening of the pores. The opening of the pores allows the water in the body to escape to the outside world. For this reason, the pores need to be closed during drying.

It is two cells called guard cells that regulate the opening and closing of stomata. The guard cell potassium (K) ion transporter (K ⁺ channel K ⁺ tonrance porter pump) controls the guard cell volume. In Arabidopsis thaliana, a model plant, potassium (K) ion channels (KAT1, KAT2, AKT1) that absorb K ⁺ (K ⁺ may be simply referred to as K in the present specification) from extracellular to intracellular, There are K ⁺ channels (GORK, SKOR) that expel potassium ions (K ⁺ ) from the inside of the cell to the outside of the cell, and AKT2 that transports K ⁺ in both directions. In particular, KAT1, KAT2 and GORK are known to function well in stomata.

According to previous reports and textbooks, when guard cells swell (that is, stomata open), the inward channels KAT1 and KAT2 become open and activated. At the same time, the outward channel (GORK) is closed.
On the other hand, when the guard cells contract (that is, the stomata close), the inward channels KAT1 and KAT2 become close and are activated. At the same time, the outward channel (GORK) becomes open.

Potassium ion transporters are also used for purposes other than controlling the opening and closing of such pores. The potassium ion transporter also functions mainly in the absorption and excretion of potassium ions performed in the roots. By controlling the function of the potassium ion transporter by catechins, nutrient absorption and intracellular ion environment will be regulated, and it will be possible to control the function of plants. Furthermore, the potassium ion transporter also functions in the ingress and egress of potassium ions in the vascular system (conduit and phloem), which is a conducting tissue. Functions can be controlled. Furthermore, since the potassium ion transporter also functions in flowers, which are reproductive tissues, fertilization and fruit formation are controlled by controlling the function of this transporter.

According to theory, it has been actually reported that plant mutants in which the expression levels of KAT1 and KAT2 of the inward channel are reduced have drought tolerance because the stomatal closure is promoted (Non-Patent Document 1; Plant Physiology). , (2001), 127, 473-485).

Patent Document 1 (WO2012 / 008042) discloses a method for imparting plant stress resistance to plants that promotes growth in an environment in which various stresses occur on the plant, and cellulose derivatives and catechins having specific components. A composition containing water and water is used, and a plant stress tolerance-imparting agent composition having a cellulose derivative content of 45.0 to 99.5% by weight is used under stress cultivation conditions having a plant stress rate of 111 to 200%. It is characterized by including a step of applying to a plant in.
According to Patent Document 1, a composition containing a specific cellulose derivative having almost no plant vitality and catechins having almost no ability to impart stress resistance as main components in an appropriate plant growing environment is described above. It discloses that a plant is endowed with unexpected stress tolerance in an environment where the plant is stressed (Patent Document 1, paragraph [0022]).

On the other hand, in pharmaceuticals for humans, many ion channel inhibitors / ion channel blockers (referred to as channel blockers and the like) that target ion transporters have been developed (for example,). , Glybenclamid, an animal ATP-dependent K channel inhibitor (such as Euglucon®).

WO2012 / 008042 Gazette

Plant Physiology, (2001), 127, 473-485

However, to date, there have been no function inhibitors or blockers targeting plant potassium ion transporters.
In relation to the present invention, there are some prior literatures relating to the use of catechins as pesticides due to their antibacterial action and as adsorbents, but no prior patent literatures relating to the use of catechins as water regulators.
Therefore, an object of the present invention is to provide a function control agent (function inhibitor and / or function activator) targeting a plant potassium ion transporter.
Furthermore, the present invention is to provide a method for growing a modified plant body, in which a function control agent targeting the transporter of the plant is applied to the plant.

The ingress and egress of ions is regulated by opening and closing the ion transporter (ion channel transporter pump) on the biological membrane of living organisms. In response to changes in the intracellular ion concentration, water flows in and out, and the cell volume also changes.
We found that at least two catechins (catechin gallate derivatives) effectively inhibit plant potassium ion transporters (K ⁺ channels), specifically eight natural catechins (catechin gallate derivatives). Of the catechin compounds (sometimes referred to as catechin compounds), two types, namely catechin gallate (sometimes abbreviated as CG) and gallocatechin gallate (sometimes abbreviated as GCG), are guard cells and plants. We have found that it inhibits six K ⁺ channels of plants KAT1, KAT2, AKT1, AKT2 (AKT3), GORK, and SKOR that function in the tube bundle system.

That is, it is shown that the above two types of catechins are K transporter inhibitors with high specificity and selectivity, while inhibiting four types of K ⁺ channels (all K ⁺ channels) other than KAT1 and KAT2. did. When the above two types of catechins are given to plants, it is considered that both inward K ⁺ channels and outward K ⁺ channels are inhibited at the same time. This suggests that by selectively developing unilateral K ⁺ channel inhibitors, more effective control of cell volume becomes possible.

（式中、Ｒ¹～Ｒ ¹⁰ は、それぞれ独立して、水素原子、Ｃ１～６の直鎖状もしくは分岐状の飽和もしくは不飽和のアルキル基、アルコキシ基またはアルキルエステル基、ハロゲン原子、ニトロ基、シアノ基、ヒドロキシ基、１級、２級または３級アミノ基、トリハロメチル基、フェニル基及び置換フェニル基からなる群から選ばれる１価基を表す。）
で示されるカテキンガレート化合物を含む植物のカリウムイオン輸送体の機能制御剤。
［２］ 前記カテキンガレート化合物が、前記一般式（１）′中のＲ¹～Ｒ¹⁰が水素原子である下記式（１－１）

で示されるカテキンガレート（ＣＧ）、または一般式（１）′中のＲ²が水酸基であり、Ｒ¹、Ｒ³～Ｒ¹⁰が水素原子である下記式（１－２）

で示されるガロカテキンガレート（ＧＣＧ）である、前項１に記載の植物のカリウムイオン輸送体の機能制御剤。
［３］一般式（１）″

（式中、Ｒ ¹ ～Ｒ ¹⁰ は、それぞれ独立して、水素原子、Ｃ１～６の直鎖状もしくは分岐状の飽和もしくは不飽和のアルキル基、アルコキシ基またはアルキルエステル基、ハロゲン原子、ニトロ基、シアノ基、ヒドロキシ基、１級、２級または３級アミノ基、トリハロメチル基、フェニル基及び置換フェニル基からなる群から選ばれる１価基を表す。）
で示されるカテキンガレート化合物を含む植物のカリウムイオン輸送体の機能制御剤。
［４］ 前記カテキンガレート化合物が、前記一般式（１）″中のＲ ¹ ～Ｒ ¹⁰ が水素原子である下記式（１－３）

で示されるエピカテキンガレート（ＥＣＧ）、または前記一般式（１）″中のＲ ² が水酸基であり、Ｒ ¹ 、Ｒ ³ ～Ｒ ¹⁰ が水素原子である下記式（１－４）

で示されるエピガロカテキンガレート（ＥＧＣＧ）である前項３に記載の植物のカリウムイオン輸送体の機能制御剤。
［５］ 前記カリウムイオン輸送体が、ＫＡＴ１、ＫＡＴ２、ＡＫＴ１、ＡＫＴ２、ＧＯＲＫ、及びＳＫＯＲからなる群より選ばれる少なくとも１種を有するカリウムイオン輸送体である、前項３又は４記載の植物のカリウムイオン輸送体の機能制御剤。
［６］ 前項１～５のいずれか１項に記載の植物のカリウムイオン輸送体の機能制御剤を植物に施用することを特徴とする植物の育成方法。
［７］ 前記カリウムイオン輸送体の機能制御がカリウムイオン輸送体の機能阻害である前項６に記載の植物の育成方法。
［８］ 前記カリウムイオン輸送体の機能制御がカリウムイオン輸送体の機能活性化である前項６に記載の植物の育成方法。
［９］ 植物に、乾燥耐性の付与、炭酸ガス取り込み阻害による植物体の矮小化、作物サイズの調節、収穫時期の変化、植物体のみずみずしさの増強、植物体や実の糖度の調節（変化）、根の成長促進性の変化、葉の肉厚の変化、及び低カリウム化から選択される少なくとも１種の機能を付与する前項６～８のいずれかに記載の植物の育成方法。
The present invention relates to a function control agent (inhibitor and / or activator) for the potassium ion transporter of the plants according to the following [1] to [2], which contains the catechin compound represented by the general formula (1) ′ , and the general formula ( 1) "Functional regulators (inhibitors and / or activators) of the potassium ion transporters of the plants of the following [3] to [5] containing the catechin compound represented by", and the plants of [ 6 ] to [ 9 ]. Regarding the training method of.
[1] General formula (1) ′

( In the formula, R ¹ to R ¹⁰ are independently hydrogen atoms, linear or branched saturated or unsaturated alkyl groups of C1 to C6, alkoxy groups or alkyl ester groups, halogen atoms, and nitro groups. , Cyano group, hydroxy group, primary, secondary or tertiary amino group, trihalomethyl group, phenyl group and substituted phenyl group .
A function regulator of a plant potassium ion transporter containing a catechin gallate compound indicated by.
[2] The catechin gallate compound has the following formula (1-1) in which R ¹ to R ¹⁰ in the general formula (1) ′ are hydrogen atoms.

Catechin gallate (CG) represented by, or the following formula (1-2) in which R ² in the general formula (1) ′ is a hydroxyl group and R ¹ , R ³ to R ¹⁰ are hydrogen atoms.

The function control agent for the potassium ion transporter of the plant according to the above item 1, which is gallocatechin gallate (GCG) represented by.
[3] General formula (1) ″

(In the formula, R ¹ to R ¹⁰ are independently hydrogen atoms, linear or branched saturated or unsaturated alkyl groups of C1 to C1, alkoxy groups or alkyl ester groups, halogen atoms, and nitro groups. , Cyano group, hydroxy group, primary, secondary or tertiary amino group, trihalomethyl group, phenyl group and substituted phenyl group.
A function regulator of a plant potassium ion transporter containing a catechin gallate compound indicated by.
[4] The catechin gallate compound has the following formula (1-3) in which R ¹ to R ¹⁰ in the general formula (1) ″ are hydrogen atoms.

Epicatechin gallate (ECG) represented by the above formula, or the following formula (1-4) in which R ² in the general formula (1) ″ is a hydroxyl group and R ¹ , R ³ to R ¹⁰ are hydrogen atoms.

The function control agent for the potassium ion transporter of the plant according to item 3 above, which is epigallocatechin gallate (EGCG) represented by.
[5] The potassium ion of the plant according to the above item 3 or 4, wherein the potassium ion transporter is a potassium ion transporter having at least one selected from the group consisting of KAT1, KAT2, AKT1, AKT2, GORK, and SKOR. Transporter function control agent.
[ 6 ] A method for growing a plant, which comprises applying the function control agent for the potassium ion transporter of the plant according to any one of the preceding items 1 to 5 to the plant.
[ 7 ] The method for growing a plant according to item 6 above, wherein the function control of the potassium ion transporter is the functional inhibition of the potassium ion transporter.
[ 8 ] The method for growing a plant according to item 6 above, wherein the function control of the potassium ion transporter is the functional activation of the potassium ion transporter.
[ 9 ] Improving drought tolerance to plants, reducing the dwarfing of plants by inhibiting carbon dioxide gas uptake, adjusting crop size, changing harvest time, enhancing the freshness of plants, adjusting the sugar content of plants and fruits (changes) ), The method for growing a plant according to any one of 6 to 8 above, which imparts at least one function selected from changes in root growth promoting property, changes in leaf wall thickness, and hypopotassium.

By controlling the K ⁺ ion channels with the function control agent of the potassium ion transporter (K ⁺ channel, K ⁺ tonrance porter pump) of the plant of the present invention, evaporation during drying can be suppressed and in a favorable environment. It is possible to promote the absorption of CO ₂ from the pores. By externally spraying or adding catechins that target potassium ion transporters, it is possible to control plant growth and differentiation and promote adaptation to environmental changes. This makes it possible to regulate (control) plant growth and enhance environmental resistance without relying on molecular breeding or genetic manipulation.

Eight catechins tested for their effect on K ⁺ current (generation and amount of current) of African Tsumegael egg mother cell biological membrane K ⁺ channel: catechin, epicatechin, gallocatechin, epigallo The chemical structural formulas of catechin (Epigallocatechin), catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate are shown. The results of addition of 8 kinds of catechins to K ⁺ current of KAT1 channel are shown. The results of addition of 8 kinds of catechins to K ⁺ current of KAT2 channel are shown. The effect (B) of catechin gallate on the K ⁺ current of the KAT2 channel is shown ((A) is an additive-free control). The effect (B) of Epicatechin gallate on the K ⁺ current of the KAT2 channel is shown ((A) is an additive-free control). The effect (B) of gallocatechin gallate on the K ⁺ current of the KAT2 channel is shown ((A) is an additive-free control). The effect (B) of Epigallocatechin gallate on the K ⁺ current of the KAT2 channel is shown ((A) is an additive-free control). The results of an experiment of inhibiting catechin gallate against 6 types of K ⁺ channels (KAT1, KAT2, AKT1, AKT2, GORK and SKOR) are shown. The results of an experiment of inhibiting Gallocatechin gallate against 6 types of K ⁺ channels (KAT1, KAT2, AKT1, AKT2, GORK and SKOR) are shown.

Embodiment of the invention

The present invention provides a function control agent for a plant potassium ion transporter, which comprises a catechin compound represented by the following general formula (1).

In formula (1), R ¹ to R ⁷ are independently hydrogen atoms, linear or branched saturated or unsaturated alkyl groups of C1 to C1, alkoxy groups or alkyl ester groups, halogen atoms, and the like. Represents a monovalent group selected from the group consisting of a nitro group, a cyano group, a hydroxy group, a primary, secondary or tertiary amino group, a trihalomethyl group, a phenyl group and a substituted phenyl group, or R ¹ to R ⁷ . At least two hydrocarbon chains are bonded to each other at arbitrary positions to form a cyclic structure of at least one 3- to 7-membered ring of saturated or unsaturated hydrocarbons together with carbon atoms substituted with such groups. Divalent groups may be formed. The alkyl group, alkoxy group, alkyl ester group represented by R ¹ to R ⁷ , or the cyclic hydrocarbon chain formed by them may have any number of carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, and imino bonds. It may be included. R ⁸ to R ¹⁰ are independent of each other, a hydrogen atom, a linear or branched saturated or unsaturated alkyl group of C1 to C1, an alkoxy group or an alkyl ester group, a halogen atom, a nitro group, a cyano group, and a hydroxy. A monovalent group selected from the group consisting of a group consisting of a primary, secondary or tertiary amino group, a trihalomethyl group, a phenyl group and a substituted phenyl group, or an alkyl group or an alkoxy group represented by R ⁸ to R ¹⁰ above. The alkyl ester group, or the cyclic hydrocarbon chain formed by them, may contain any number of carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, imino bonds.

In the catechin compound represented by the general formula (1) used in the present invention, preferably, R ¹ to R ⁷ in the formula are independently saturated with hydrogen atoms and C1 to 6 in a linear or branched manner. Alternatively, a group consisting of an unsaturated alkyl group, an alkoxy group or an alkyl ester group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a primary secondary or tertiary amino group, a trihalomethyl group, a phenyl group and a substituted phenyl group. Represents a monovalent group selected from.
The alkyl group, alkoxy group, and alkyl ester group represented by R ¹ to R ⁷ may contain any number of carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl, and imino bonds. R ⁸ to R ¹⁰ are independent of each other, hydrogen atom, linear or branched saturated or unsaturated alkyl group of C1 to C1, alkoxy group or alkyl ester group, halogen atom, nitro group, cyano group, hydroxy. A monovalent group selected from the group consisting of a primary, secondary or tertiary amino group, a trihalomethyl group, a phenyl group and a substituted phenyl group, or an alkyl group or an alkoxy group represented by R ⁸ to R ¹⁰ above. The alkyl ester group may contain any number of carbonyl, ether, ester, amide, sulfide, sulfinyl, sulfonyl and imino bonds.
Further, in the general formula (1) used in the present invention, preferably, catechin gallate (CG) represented by the following formula (1-1) in which R ¹ to R ¹⁰ in the general formula (1) are hydrogen atoms. ), Or catechin, which is gallocatechin gallate (GCG) represented by the following formula (1-2), in which R ² in the general formula (1) is a hydroxyl group and R ¹ , R ³ to R ¹⁰ are hydrogen atoms. Classes are used as functional regulators of plant potassium ion transporters.

Furthermore, the present invention can provide a method for growing a desired plant by applying the catechins represented by the general formula (1) to a plant as a function control agent for a potassium ion transporter of the plant. .. The function control of the potassium ion transporter may be, for example, a method of controlling the function of the potassium ion transporter by inhibiting the function, or a method of controlling plant growth that activates the function of the potassium ion transporter. May be.

Further, in the present invention, by applying the catechins represented by the general formula (1) to the plant, the plant is imparted with drought tolerance, the dwarfing of the plant body by inhibiting the uptake of carbon dioxide gas, and the adjustment of the crop size. Selected from the group consisting of changes in harvest time, enhancement of freshness of plants, regulation (change) of sugar content of plants and fruits, changes in root growth promotion, changes in leaf thickness, and low potassium. At least one function can be imparted.

The function control agent for the potassium ion transporter of the plant of the present invention is applied in various dosage forms containing an effective amount of the compound of the general formula (1), (1-1) or (1-2). Usually, it is mixed with a carrier, a liquid carrier, or a gas carrier, and if necessary, a surfactant, a bulking agent, a colorant, a binder, an antifreeze agent, an ultraviolet absorber, etc. are added to add an oil agent, an emulsion, etc. It is formulated and applied to solubilizers, wettable powders, suspending agents, flowable agents, powders and the like. The part of the plant to be applied, the time of application, the method of application and the like are not particularly limited, and can be appropriately selected according to the purpose.

Hereinafter, the function control agent for the potassium ion transporter (K ⁺ channel, K ⁺ tonrance porter, pump) of the present invention will be described.
[Introduction of potassium ion channel genes into oocytes and electrophysiological measurement of transport activity]
The potassium ion channel gene is introduced into African Tumegael egg mother cells by a known method to induce the expression of K ⁺ channels, and the K ⁺ current of the K ⁺ channels expressed on the biological membrane of the egg mother cells expressing the K ⁺ channels. The presence or absence of generation and the amount of its current were electrophysiologically measured with and without the addition of catechins contained as tea components to evaluate the degree of inhibition of various catechins on K ⁺ transporters.

That is, after RNA synthesis was performed using DNA encoding 6 types of K ⁺ channels (KAT1, KAT2, AKT1, AKT2, GORK, SKOR) which are potassium ion transporters (K ⁺ transporters) as a template, each RNA was synthesized. Was introduced into Xenopus oocytes by a known method. Each oocyte was incubated at 16-20 ° C. for 1-3 days to induce K ⁺ channel expression.

For oocytes expressing K ⁺ channels, the presence or absence of K ⁺ current generation of K ⁺ channels expressed on the biological membrane of oocytes using the following measurement solutions 1 and 2 and the amount of the current are described below. The degree of inhibition of each catechin on the K ⁺ transporter was evaluated by electrophysiological measurement with and without addition of the eight types of catechins. The eight types of catechins are known compounds, and commercially available products were used.

Measuring liquid 1 (for KAT1, KAT2, AKT1 and AKT2)
120 mM KCl, 1 mM MgCl ₂ , 1 mM CaCl ₂ , 10 mM HEPES-NaOH pH 7.3.
Measuring liquid 2 (for GORK and SKOR)
12 mM KCl, 108 mM NaCl, 1 mM MgCl ₂ , 1 mM CaCl ₂ , 10 mM HEPES-NaOH, pH 7.3.

Predetermined catechins are added to each of the above-mentioned measuring solution 1 containing the oocytes expressing KAT1, KAT2, AKT1, or AKT2 and the above-mentioned measuring solution 2 containing the oocytes expressing GORK or SKOR. Then, the presence or absence of K ⁺ current generated in the K ⁺ channel expressed in the biological membrane of the oocyte and the amount of the current are determined using a membrane potential fixing device (AxoClamp 2B two-electrode voltage clamp amplifier (Axon Instruments)). , Electrophysiologically measured. In the measurement of KAT1, KAT2, AKT1 and AKT2, the membrane potential was kept constant for 0.5 seconds in steps of 20 mV from +10 mV to −170 mV. In the measurement of GORK and SKOR, the membrane potential was kept constant for 2 seconds in steps of 20 mV from −90 mV to + 70 mV. The current generated at that time was measured. This method is known. As catechins, eight kinds of catechins whose chemical structural formulas are shown in FIG. 1: catechin (Catechin), epicatechin (Epicatechin), galocacatechin (Gallocatechin), epigallocatechin (Epigallocatechin), catechin gallate (Catechin gallate), epi Catechin gallate, Gallocatechin gallate, and Epigallocatechin gallate were used, and the degree of inhibition was evaluated by comparing the case with and without the addition.

The results of addition of the eight catechins (concentration 500 μM) to the K ⁺ current of the KAT1 channel (degree of inhibition of catechins of the KAT1 channel) are shown in FIG. 2, and the eight catechins (concentration 500 μM) to the K ⁺ current of the KAT2 channel are shown in FIG. ) The result of the addition (the degree of catechin inhibition of the KAT2 channel) is shown in FIG. In FIGS. 2 and 3, the vertical axis (inhibition degree) is standardized with the K current amount of the K channel expressed on the biological membrane of the control (system to which catechins are not added) as 1, and when catechins are added. It is shown by the relative ratio of the amount of K current.
Of the eight types of catechins, catechin gallate and gallocatechin gallate were found to have inhibitory activity. When catechin gallate and gallocatechin gallate are added, KAT1 channel and KAT2 channel are significantly inhibited, and as a result, a significant decrease in K ⁺ current is observed, which inhibits the function of absorbing K ⁺ from extracellular to intracellular. It turned out to be.

The effect of adding catechin gallate on the K ⁺ current of the KAT2 channel is shown in FIG. In FIG. 4, the time change of K ⁺ current of K ⁺ channel is compared between the additive-free system (A) (in the figure, none) and the additive system (B) (indicated as + catechin gallate in the figure). Catechin gallate showed a large inhibitory activity on the KAT2 channel (a significant decrease in the current value associated with the transfer of K ⁺ ) .
Further, FIG. 6 shows the effect of adding Gallocatechin gallate on the K ⁺ current of the KAT2 channel. From the comparison of the additive-free system (A) (in the figure, none) and the additive system (B) (indicated as + gallocatechin gallate in the figure) in FIG. 6, gallocatechin gallate is compared with respect to the KAT2 channel. It showed great inhibitory activity.

As shown in FIGS. 2 and 3 above, the other four types of K ⁺ for catechin gallate and gallocatechin gallate that showed inhibitory activity against the K ⁺ current of the KAT1 channel and the KAT2 channel. The results of examining the inhibitory activity on channels (AKT1, AKT2, GORK and SKOR) are shown in FIGS. 8 (catechin gallate-added system) and FIG. 9 (gallocatechin gallate-added system). “None” described at the bottom left of FIGS. 8 and 9 indicates the amount of K ⁺ current when catechins are added, where 1 is the current amount when oocytes that do not express potassium ion channels are used. , It is expressed by the relative current rate. It was found that catechin gallate and epigallocatechin gallate have inhibitory activity for both K ⁺ channels, although the degree of activity varies depending on the type of K ⁺ channel.

Eight kinds of catechins shown in FIG. 1 tested in this example: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin. Among gallate (Epicatechin gallate), gallocatechin gallate (Gallocatechin gallate), and epigallocatechin gallate (Epigallocatechin gallate), catechin gallate and gallocatechin gallate having high inhibitory activity on the K ⁺ channel have a chemical structure and a three-dimensional structure. In the present invention, these catechins regulate the opening and closing of pores, especially the potassium (K) ion transporter of the guard cells (K ⁺ channel K ⁺ tonlance porter pump). It was found that there is a structure-activity relationship with a three-dimensional structure, and a function control agent for a potassium ion transporter of a plant containing the catechin gallate derivative represented by the general formula (1) and this function control agent of a plant to be applied to a plant. Completed the invention of the breeding method.

The K ⁺ ion channel can be controlled by the functional control agent of the potassium ion transporter (K ⁺ channel K ⁺ tonrance porter pump) of the plant containing the catechin compound represented by the general formula (1) of the present invention. It was found that it functions well in the stomata (swelling of guard cells), especially by inhibiting the potassium (K) channels (KAT1, KAT2) that absorb K from outside the cell to the inside of the cell. It is possible to suppress evaporation during drying and promote CO ₂ absorption from stomata in a favorable environment. By spraying or adding a function control agent targeting an ion transporter from the outside, plant growth It is possible to control differentiation and promote adaptation to environmental changes. As a result, without relying on molecular breeding or genetic manipulation, it imparts drought tolerance to plants, reduces the size of plants by inhibiting the uptake of carbon dioxide, adjusts the size of crops, changes the harvest time, enhances the freshness of plants, and enhances the freshness of plants. It is possible to regulate (change) the sugar content of the fruit, change the growth promoting property of the root, change the thickness of the leaf, and grow a plant that imparts the function of a low potassium plant.

The target plants are not particularly limited and are all kinds of plants. In addition to the model plant Arabidopsis, crops used in agriculture and industry, plants for materials, plants for environmental improvement (street trees, windbreak forests, etc.), trees, photosynthetic organisms (orchid algae, algae, etc.) are targeted. (Posted on the Ministry of Agriculture, Forestry and Fisheries website "Algae, algae, beans, fertilizer crops, craft crops; http://www.maff.go.jp/j/tokei/kouhyou/sakumotu/sakkyou_kome/index.html"" reference).
A typical example is shown below. Plants that are edible crops and industrial plants (raw materials for bioethanol and bioplastics): rice (rice paddy rice land rice), wheat such as wheat and barley, potatoes such as sweet potato, potato, cassava (tapioca), beans, Fruits such as forage crops (grass, solgo, etc.), corn, hakusai, lettuce, ice plant, cabbage, spinach, lentil, eggplant, cucumber, tensai, gobo, carrot, sesame, citrus, citrus, strawberry, melon, banana, pineapple, etc. Kinds, industrial crops such as mulberry, pine, beech, cedar, hinoki, mangrove, rubber and other trees (trees), arid land plants such as corn and ryuzetsuran.
In agriculture, potassium, phosphorus and nitrogen are the three major nutrients of plants, and cell transport of potassium is involved in maintaining cell activity. Inhibition of K ⁺ absorption system K ⁺ channels (KAT1, KAT2, AKT1) and activation of K ⁺ excretion system K ⁺ channels (GORK, SKOR) reduce the amount of K ⁺ in cells. On the contrary, activation of K ⁺ absorption system K ⁺ channels (KAT1, KAT2, AKT1) and inhibition of K ⁺ excretion system K ⁺ channels (GORK, SKOR) increase the amount of K ⁺ in cells. .. In the present invention, it is possible to increase or decrease the activity of cells by selective functional control by catechin. This makes it possible to adjust the absorption rate of K ⁺ , promote or suppress the growth of plants, regulate the amount of transpiration, and regulate the absorption of carbon dioxide through the stomata.
It is known that all plants have the same type of K ⁺ transporter as KAT1 (homolog: ortholog; homologous transporter). In addition, the catechin gallate derivative functioning with six types (KAT1, KAT2, AKT1, AKT2, GORK, SKOR) is preferably used in growing plants such as cereals (rice, wheat, barley, etc.), fruit trees, vegetables (cabbage corn), and the like. A special effect can be manifested. Furthermore, the use of the catechin gallate derivative disclosed in the present invention can be utilized for production control related to growth in the plant industry.

Claims (9)

General formula (1) ′

( In the formula, R ¹ to R ¹⁰ are independently hydrogen atoms, linear or branched saturated or unsaturated alkyl groups of C1 to C6, alkoxy groups or alkyl ester groups, halogen atoms, and nitro groups. , Cyano group, hydroxy group, primary, secondary or tertiary amino group, trihalomethyl group, phenyl group and substituted phenyl group .
A function regulator of a plant potassium ion transporter containing a catechin gallate compound indicated by. The catechin gallate compound has the following formula (1-1) in which R ¹ to R ¹⁰ in the general formula (1) ′ are hydrogen atoms.

Catechin gallate (CG) represented by, or the following formula (1-2) in which R ² in the general formula (1) ′ is a hydroxyl group and R ¹ , R ³ to R ¹⁰ are hydrogen atoms.

The function control agent for a potassium ion transporter of a plant according to claim 1, which is gallocatechin gallate (GCG) represented by. General formula (1) ″

(In the formula, R ¹ ~ R ^Ten Are independently hydrogen atoms, linear or branched saturated or unsaturated alkyl groups of C1-6, alkoxy or alkyl ester groups, halogen atoms, nitro groups, cyano groups, hydroxy groups, primary. Represents a monovalent group selected from the group consisting of a secondary or tertiary amino group, a trihalomethyl group, a phenyl group and a substituted phenyl group. )
A function regulator of a plant potassium ion transporter containing a catechin gallate compound indicated by. The catechin gallate compound is R in the general formula (1) ″. ¹ ~ R ^Ten Is a hydrogen atom by the following equation (1-3)

Epicatechin gallate (ECG) represented by, or R in the general formula (1) ″. ² Is a hydroxyl group, R ¹ , R ³ ~ R ^Ten Is a hydrogen atom by the following equation (1-4)

The function control agent for a potassium ion transporter of a plant according to claim 3, which is epigallocatechin gallate (EGCG) represented by. The potassium ion transporter of the plant according to claim 3 or 4, wherein the potassium ion transporter is a potassium ion transporter having at least one selected from the group consisting of KAT1, KAT2, AKT1, AKT2, GORK, and SKOR. Function control agent. A method for growing a plant, which comprises applying the function control agent for the potassium ion transporter of the plant according to any one of claims 1 to 5 to the plant. The method for growing a plant according to claim 6 , wherein the function control of the potassium ion transporter is the functional inhibition of the potassium ion transporter. The method for growing a plant according to claim 6 , wherein the function control of the potassium ion transporter is the functional activation of the potassium ion transporter. Improving drought tolerance, reducing plant size by inhibiting carbon dioxide uptake, adjusting crop size, changing harvest time, enhancing freshness of plant, adjusting (change) sugar content of plant and fruit, root The method for growing a plant according to any one of claims 6 to 8 , which imparts at least one function selected from a change in growth promoting property, a change in leaf thickness, and a reduction in potassium.

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