Injection device for injecting liquid into plant leaves and injection head of injection device

Abstract

The invention relates to an injection device for injecting liquid into plant leaves and an injection head of the injection device, the injection head comprises a cylinder body, the cylinder body comprises a first opening, a second opening and a liquid channel, the first opening is arranged at the first end of the cylinder body, the second opening is arranged at the second end of the cylinder body, the liquid channel is arranged in the cylinder body, and the first opening is communicated with the second opening; the first opening is communicated with the second opening and used for allowing liquid to pass through; the one or more first bulges are arranged at the second end of the cylinder body and are used for forming injury openings in the plant leaves; the second end of the cylinder is suitable for being in contact with a plant leaf, and a liquid space separated from the outer part of the cylinder is formed between the damage opening and the second end of the cylinder by utilizing the plant leaf. The injection head disclosed by the invention does not puncture an operator, the gene introduction effect is good, and the damage to plants is relatively small.

Description

Technical Field

[0001] This invention relates to the field of injection devices, and particularly to an injection device and its injection head for injecting liquid into plant leaves. Background Technology

[0002] In scientific research, daily study, crop improvement, and other related activities, it is often necessary to improve plant traits by introducing exogenous genes into plants to regulate target traits such as bioluminescence and morphological changes. For example, in transient gene expression technology, the target gene is transferred into target cells within a relatively short period of time, constructing a temporary and highly efficient expression system within the cell, enabling the target gene to achieve a short-term high level of expression. This technology is not only suitable for cell biology research related to gene-protein interactions, but has also been successfully applied in recent years to related experiments on various crops and horticultural plants, showing broad application prospects.

[0003] Currently, the common method for introducing exogenous genes into plants is to use an injection device to inject the exogenous gene into the plant leaves or other suitable parts. However, existing injection devices are mostly ordinary medical syringes, micro-samplers, or simple modified devices, which have many drawbacks in actual operation: First, the injection process causes significant damage to plant tissues, which can easily affect normal plant growth and the effectiveness of exogenous gene introduction; second, the injection volume is difficult to control precisely, and too much or too little injection can lead to experimental errors, affecting the accuracy of the research; third, the device is not easy to operate, and operators are very likely to be pricked by the needle during the injection process, posing a safety hazard; fourth, the control of the injection timing and the selection of the injection site require high operating skills, which poses a severe test to the operator's proficiency and is not conducive to efficient batch injection operations. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention proposes an injection head for injecting liquid into plant leaves, comprising: a cylinder including a first opening, a second opening, and a liquid channel, wherein the first opening is disposed at a first end of the cylinder, the second opening is disposed at a second end of the cylinder, and the liquid channel is disposed inside the cylinder and connects the first opening and the second opening for accommodating the passage of liquid; and one or more first protrusions disposed at the second end of the cylinder for forming a wound on the plant leaf; wherein the second end of the cylinder is adapted to contact the plant leaf and utilize the plant leaf to form a liquid space separated from the outside of the cylinder between the wound and the second end of the cylinder.

[0005] In the injection head described above, the pressure in the liquid space is greater than the external pressure during liquid injection.

[0006] As described above, the injection head has a second end of the barrel including an annular end face that is adapted to adhere to the plant leaf when the first protrusion pierces the plant leaf, thereby defining a liquid space isolated from the outside.

[0007] The injection head described above further includes: one or more second protrusions disposed at the second end of the barrel; wherein the height of the second protrusion is less than or lower than the height of the first protrusion.

[0008] The injection head as described above, wherein the barrel further includes: one or more partition strips disposed in the second opening, dividing the second opening into multiple portions; wherein a first protrusion and / or a second protrusion are disposed on the partition strips and extend outward from the barrel.

[0009] As described above, in the injection head, a first protrusion is located at the center of a second opening, and a second protrusion is symmetrically located on both sides of the first protrusion.

[0010] The injection head as described above, wherein all or part of the first protrusion and / or the second protrusion are disposed on the annular end face.

[0011] The injection head described above has a liquid channel comprising a first portion and a second portion, wherein the size of the second portion gradually decreases from the first opening to the second opening.

[0012] In the injection head described above, the angle of the end of the first protrusion is 50-60°, preferably 53-56°. The injection head as described above, wherein the first protrusion includes a first surface and a second surface arranged at an angle, wherein the angle is the included angle between the first surface and the second surface.

[0013] The injection head described above has a first protrusion whose height is 2-5 times the thickness of the plant leaf.

[0014] According to another aspect of this application, an injection device for injecting liquid into plant leaves is provided, comprising: an injection head as described above.

[0015] According to another aspect of this application, a method for injecting liquid into plant leaves is proposed, comprising: extracting liquid through an injection device; placing a first side of the plant leaf on a flexible object, inserting the injection head of the injection device into the plant leaf from a second side of the plant leaf to form a lesion on the plant leaf; as the protrusion of the injection head penetrates into the plant leaf, the plant leaf adheres to the injection head to form a liquid space separated from the outside of the cylinder between the lesion and the second end of the cylinder; and pushing the liquid in the body, the liquid entering the plant leaf through the lesion.

[0016] The method described above, wherein the second side of the plant leaf is the back of the plant leaf that is shaded.

[0017] The method described above further includes: stopping the application of the infection solution when the plant leaf shows a wet patch, or the area of ​​the wet patch can no longer expand, or the area of ​​the wet patch occupies the entire plant leaf.

[0018] This application, by designing the structure of the injection head, prevents injury to operators when introducing exogenous genes into plants. The operation is simple and convenient, the gene introduction effect is good, the damage to plants is minimal, and operators do not need to have a high level of skill. Attached Figure Description

[0019] The preferred embodiments of the present invention will now be described in further detail with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of an injection device according to an embodiment of this application; Figures 2A-2F This is a schematic diagram of an injection head structure according to an embodiment of this application; Figures 3A-3C This is a schematic diagram of the structure of the injection device discharging the infectious liquid according to an embodiment of this application; Figures 4A-4D A diagram illustrating an existing plant transient transformation according to an embodiment of this application; Figures 5A-5C This is an experimental diagram of an injection device according to an embodiment of this application; Figure 6A and Figure 6B This is a comparative experimental diagram of an injection device according to an embodiment of this application and a prior art device; Figure 7 This is a schematic diagram of an injection head structure according to another embodiment of this application; Figure 8 This is a schematic diagram of an injection head structure according to another embodiment of this application; Figure 9 This is a schematic diagram of an injection head structure according to another embodiment of this application; Figure 10 This is a schematic diagram of an injection head structure according to another embodiment of this application; Figure 11 A schematic diagram of an injection head structure according to another embodiment of this application; and Figure 12 This is a flowchart illustrating the use of an injection device according to an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the following detailed description, reference can be made to the accompanying drawings, which form part of this application and illustrate specific embodiments of the present application. In the drawings, similar reference numerals describe substantially similar components in different figures. Specific embodiments of the present application are described in sufficient detail below to enable those skilled in the art to implement the technical solutions of the present application. It should be understood that other embodiments may also be utilized, or structural, logical, or electrical changes may be made to the embodiments of the present application.

[0022] This application proposes a novel injection device that uses a special injection head to cut open the plant's epidermis and inject a liquid containing exogenous genes into the plant through the cut wound. Moreover, the injection head will not injure the operator, making the operation simple and convenient, with good gene introduction effect, minimal damage to the plant, and no need for the operator to have a high level of skill.

[0023] The technical solutions of this application are further illustrated below through specific embodiments. Those skilled in the art should understand that, based on the teachings of the following embodiments, other alternative solutions capable of achieving the same or similar functions are possible. These alternative solutions are also within the protection scope of this application.

[0024] Figure 1 This is a schematic diagram of an injection device according to an embodiment of the present application.

[0025] As shown in the figure, the injection device 100 includes a main body 110 and an injection head 120. The main body 110 can contain a liquid containing a foreign gene. The injection head 120 is disposed at one end of the main body 110 and can be used to puncture the epidermis of a plant leaf, providing a liquid flow channel between the puncture site on the plant leaf and the main body 110. The main body 110 can control the liquid to enter the plant leaf from the injection head, thereby injecting liquid into the plant. In some embodiments, the main body 110 can be a syringe, which can draw up liquid and push the drawn liquid out of the injection head. In some embodiments, the main body 110 and the injection head 120 can be integrally formed.

[0026] The structure of the injection head of this application will be described in detail below.

[0027] Figures 2A-2FThis is a schematic diagram of an injection head structure according to an embodiment of this application.

[0028] As shown in the figure, the injection head 200 includes a cylindrical body 210 and a protrusion 220. The first end of the cylindrical body 210 can be used to connect to the main body; the protrusion 220 is disposed at the second end of the cylindrical body 210 and extends outward from the cylindrical body 210, and can be used to pierce the epidermis of the plant.

[0029] In some embodiments, the first end of the barrel 210 may include a first opening 211, which can be used for connection between the injection head and the body. For example, the end of the body connected to the injection head can be inserted into the first opening 211. In some embodiments, the diameter of the first opening 211 may be 4.2 mm so that the injection head can be adapted to a conventional syringe.

[0030] In some embodiments, the second end of the cylinder 210 may include a second opening 212, which can be used to receive liquid exiting the injection head and entering the plant. In some embodiments, the cross-sectional area of ​​the second opening is smaller than that of the first opening, so that the flow rate of the liquid increases after passing through the first and second openings, and the liquid forms a slight positive pressure at the puncture site on the plant epidermis, thereby facilitating the liquid's entry into the plant. In some embodiments, the cross-sectional area of ​​the first opening may be 2-4 times that of the second opening, preferably 2.5-3 times, and more preferably 2.8 times.

[0031] In some embodiments, the interior of the cylinder 210 may further include a liquid channel 213, which connects the first opening 211 and the second opening 212, and can be used to accommodate liquid flow. In some embodiments, a portion of the liquid channel 213 may also be connected to the main body; for example, the end of the main body connected to the injection head can be inserted into the first opening 211, allowing partial access to the liquid channel, so that the liquid can smoothly enter the liquid channel, and also enhancing the connection strength between the injection head and the main body. In some embodiments, the liquid channel 213 may include two parts, namely a first part 2131 near the second end and a second part 2132 near the first end. The first part 2131 is cylindrical in shape, and its size is the same as that of the first opening, so that the injection head can be connected to the main body, and one end of the main body can be inserted into the first part of the liquid channel through the first opening; the size of the second part 2132 gradually tapers from the first end of the injection head to the second end, so as to change the flow rate of the liquid. In some embodiments, the shape of the second part 2132 may be a right cone, and its cone apex angle may be 20-25°, preferably 20-22°, and most preferably 21°. In some embodiments, the first portion 2131 may also be conical in shape, with its dimensions gradually decreasing from the first end to the second end of the injection head. As one end of the body is inserted into the first portion, the connection between the two becomes tighter with increasing insertion depth. In some embodiments, the cone apex angle of the first portion may be 3-6°, preferably 4-6°, and most preferably 5°.

[0032] In some embodiments, the cylinder 210 may further include a partition strip 214, which may be disposed at the second opening and located at the center of the second opening, dividing the second opening into two symmetrical parts. Liquid can exit the injection head through the second opening and enter the plant to both sides, wetting its interior. In some embodiments, the partition strip 214 has a certain width, thereby occupying a certain cross-sectional area of ​​the second opening, which can further increase the liquid flow rate and increase the pressure of the liquid entering the plant. In some embodiments, the width of the partition strip 214 may be 0.5-1 mm. In some embodiments, the partition strip may occupy 45%-55% of the cross-sectional area of ​​the second opening, preferably 47%-50%.

[0033] In some embodiments, the second end of the cylinder 210 may further include an annular plane 215, which may be on the same plane as the second opening 212 and may be used to contact and adhere to the surface of the plant, thereby sealing the plant surface and forming a liquid space between the plant surface and the second end of the cylinder, thus isolating the protrusion forming the damage opening from the external environment, so that liquid can enter the plant and prevent liquid from flowing to the outside of the plant.

[0034] In some embodiments, the protrusion 220 may include a sharp angle, the included angle of which may be 50-60°, preferably 50-55°, and most preferably 53°. In some embodiments, the protrusion 220 may be a triangular protrusion, which may be disposed at the center of the second opening of the cylinder and extend outward from the separator strip. When the annular plane 215 is in close contact with the plant surface, it can also support the leaf, so that a small cavity is formed between the injection head and the plant surface, facilitating the entry of liquid into the leaf. In some embodiments, the protrusion 220 may include a first surface 221 and a second surface 222 inclinedly disposed on the separator strip, wherein the included angle between the first surface and the second surface may be 50-60°, preferably 50-55°, and most preferably 53°, to prevent the protrusion from puncturing the plant and injuring the operator. In some embodiments, the width of the first surface and / or the second surface does not exceed the width of the separator strip to avoid the protrusion occupying a local cross-sectional area of ​​the second opening, affecting the flow of liquid, causing turbulence, and affecting the entry of liquid into the plant.

[0035] In some embodiments, the protrusion 220 extends outward from the cylinder at a height that is 2-5 times the thickness of the plant to be inserted, to ensure that the protrusion 220 pierces the plant epidermis and to prevent injury to the operator. In some embodiments, the height of the protrusion 220 can be 0.5-1.5 mm, preferably 1 mm.

[0036] The process of liquid output by the injection device of this application will be further illustrated below through a specific embodiment of plant transient transformation. In plant transient transformation, a resuspension liquid containing Agrobacterium (i.e., infection solution) needs to be injected into the plant leaves to induce luminescence expression within the plant leaves. As those skilled in the art will understand, the injection device of this application can also be used in other techniques for injecting liquids into plants.

[0037] Figures 3A-3C This is a schematic diagram of the structure of the injection device discharging the dyeing solution according to an embodiment of this application. Only a portion of the injection device's structure is shown in the figure to facilitate observation of the dyeing solution flow process.

[0038] refer to Figure 3A Before injecting the dye solution into the plant leaf 300, the plant leaf can be fixed first. For example, the operator's fingers can be placed against the first epidermis 310 of the plant leaf to fix it, and the injection device is set on one side of the second epidermis 320 of the plant leaf.

[0039] refer to Figure 3BWhen the protrusion of the syringe tip pierces into the plant leaf, it can create a wound 321 on the second epidermis 320. The deeper the protrusion penetrates into the plant leaf, the larger the wound 321 becomes. As the protrusion of the syringe tip penetrates into the plant leaf, the operator's finger will be supported and depressed by the protrusion. At the same time, the plant leaf will also be depressed towards the first surface as the protrusion penetrates.

[0040] refer to Figure 3C When the protrusion pierces the plant leaf and presses against the operator's finger, the annular plane of the injection head and the area around the finger's indentation can clamp the edge of the plant leaf's indentation and seal the area around the leaf injury 321, thus isolating the injury 321 from the external environment. A liquid space 301 can be formed between the injection head and the leaf's indentation, which facilitates the smooth entry of the infecting liquid into the plant leaf through the injury.

[0041] In some embodiments, as the liquid channel size of the injection head gradually narrows, the flow rate of the infectious liquid gradually increases as the main body pushes the infectious liquid into the injection head, creating a first pressure within the liquid channel. The liquid then flows out through the second opening via a separator strip, further increasing the flow rate and allowing it to smoothly enter the liquid space 301. Within the liquid space, the infectious liquid creates a second pressure. Because the annular plane of the injection head is closed to the leaf, the infectious liquid can smoothly enter the plant leaf through the damage port 321, creating a third pressure within the plant leaf. In some embodiments, the first pressure is greater than the second pressure, the second pressure is greater than the third pressure, and the third pressure is greater than the external air pressure. This allows the infectious liquid to smoothly enter the plant leaf under the action of the first pressure, while also preventing the infectious liquid from overflowing outside the plant leaf.

[0042] In some embodiments, even if the protrusion pierces the first epidermis 310 and abuts against the operator's finger, the protrusion's structure will not cause any damage to the operator's finger, and the infectious liquid will not flow out of the leaf from the first surface.

[0043] This application also provides actual test photos for comparison to illustrate the advantages of the injection device in practical applications.

[0044] Figures 4A-4D This is an experimental diagram of a conventional plant instantaneous rotation according to an embodiment of this application. Figures 5A-5C This is an experimental diagram of an injection device according to an embodiment of this application. Figure 6A and Figure 6B This is a comparative diagram of an injection device according to an embodiment of the present application and a conventional device.

[0045] Referring to Figure 4, existing plant transfection methods utilize a syringe. First, an opening is made in the plant leaf using the syringe needle, and then the infection solution is injected into the opening. However, making the opening with a needle is extremely risky as it can easily injure the operator, requiring a high level of experience. Furthermore, referring to… Figure 4B and Figure 4C When the dye solution is injected into the opening through a syringe, it is extremely difficult for the dye solution to enter the leaf. A large amount of the dye solution overflows to the outside of the plant leaf, resulting in the loss and waste of the dye solution.

[0046] Referring to Figure 5, after the injection device of this application draws up the infection liquid, the injection head is directly pressed against the plant leaf and the infection liquid is pushed in. The infection liquid can smoothly enter the plant leaf and very little infection liquid overflows outside the plant leaf.

[0047] Referring to Figure 6, the existing syringe method for instantaneous plant rotation causes significant damage to the plant leaves, and the infection solution does not penetrate the leaves evenly, requiring repeated injections at multiple locations. In contrast, the injection device of this application achieves instantaneous plant rotation with minimal, even negligible, damage to the plant leaves, and the infection solution penetrates the leaves evenly, eliminating the need for repeated injections.

[0048] This application also proposes other syringe head structures.

[0049] Figure 7 This is a schematic diagram of an injection head structure according to another embodiment of this application.

[0050] As shown in the figure, the injection head 700 includes a cylindrical body 710, a first protrusion 720, a second protrusion 730, and a third protrusion 740. The cylindrical body 710 and the first protrusion 720 are similar to those in the embodiment of Figure 2, and therefore will not be described again here. The second protrusion 730 and the third protrusion 740 are also disposed on the dividing strip of the cylindrical body and extend outward from the cylindrical body. The second protrusion 730 and the third protrusion 740 can be respectively disposed on both sides of the first protrusion and symmetrically arranged relative to the first protrusion. The injection device can create multiple punctures on the surface of the leaf through multiple protrusions, facilitating the entry of the infectious liquid into the leaf. In some embodiments, the height of the second and third protrusions can be lower than the height of the first protrusion. When the first protrusion abuts against the operator's finger, it may pierce the plant leaf, but the second and third protrusions will not pierce the plant leaf, effectively preventing the infectious liquid from overflowing outside the plant leaf. Furthermore, within the liquid space formed between the second end of the cylindrical body and the leaf, multiple punctures can be formed on the leaf, facilitating the entry of the liquid into the plant. In some embodiments, the heights of the second and third protrusions may be 50%, 60%, 70%, or 80% of the height of the first protrusion.

[0051] Figure 8 This is a schematic diagram of an injection head structure according to another embodiment of this application.

[0052] As shown in the figure, the injection head 800 includes a cylindrical body 810, a first protrusion 820, and a plurality of second protrusions 830. The cylindrical body 810 and the first protrusion 820 are similar to those in the embodiment of Figure 2, and therefore will not be described again here. The plurality of second protrusions 830 are disposed on the first surface of the cylindrical body and extend outward from the cylindrical body. The injection device can create multiple punctures on the surface of the leaf through the multiple protrusions, facilitating the entry of the infectious liquid into the leaf. In some embodiments, the second protrusions can be evenly distributed along the axial direction of the first surface. In some embodiments, the second protrusions are located close to the second opening on the first surface, so that the annular plane away from the second opening can be used to hold the plant leaf with the operator's fingers. In some embodiments, the height of the second protrusions can be lower than the height of the first protrusions. When the first protrusion abuts against the operator's fingers, the first protrusion may pierce the plant leaf, but the second protrusions will not, effectively preventing the infectious liquid from overflowing the plant leaf. In some embodiments, the height of the second protrusions can be 50%, 60%, 70%, or 80% of the height of the first protrusions.

[0053] Figure 9 This is a schematic diagram of an injection head structure according to another embodiment of this application.

[0054] As shown in the figure, the injection head 900 includes a cylindrical body 910 and a plurality of first protrusions 920. The cylindrical body 910, compared to the embodiment in Figure 2, does not include a separator at the second opening, and therefore will not be described further. The plurality of first protrusions 920 are disposed on the first surface of the cylindrical body and extend outwards from the cylindrical body. The injection device can pierce multiple wounds on the surface of the leaf through the multiple protrusions, facilitating the entry of the infectious liquid into the leaf. In some embodiments, the plurality of first protrusions can be evenly distributed along the axial direction of the first surface. After the infectious liquid leaves the injection head from the second outlet, it spreads outwards and can enter the plant leaf through the openings pierced by the first protrusions. In some embodiments, the first protrusions are located close to the second opening on the first surface, so that the annular plane away from the second opening can be used to hold the plant leaf with the operator's fingers.

[0055] Figure 10 This is a schematic diagram of an injection head structure according to another embodiment of this application.

[0056] As shown in the figure, the injection head 1000 includes a cylindrical body 1010, a first protrusion 1020, and a plurality of second protrusions 1030. The first protrusion 1020 and the plurality of second protrusions 1030 are connected to... Figure 8 The embodiments are similar, so they will not be described again here. The cylinder 1010 and... Figure 8Compared to the previous embodiment, the second opening of the cylinder includes two intersecting dividing strips, which can evenly divide the second opening into four parts. After the infection liquid leaves the injection head through the second opening, it can spread evenly in all directions.

[0057] Figure 11 This is a schematic diagram of an injection head structure according to another embodiment of this application.

[0058] As shown in the figure, the injection head 1100 includes a cylindrical body 1110 and multiple first protrusions 1120. The structure of the cylindrical body 1110 is similar to... Figure 10 Similarly, it will not be described again here. Multiple first protrusions 1120 are disposed on the partition strip of the cylinder and extend outward from the cylinder. The injection device can puncture multiple wounds on the surface of the blade through the multiple protrusions, which facilitates the entry of the infectious liquid into the blade.

[0059] This application also proposes a method of using an injection device to inject liquid into plants.

[0060] Figure 12 This is a flowchart illustrating the use of an injection device according to an embodiment of this application.

[0061] As shown in the figure, in step 1210, liquid is extracted. In some embodiments, when it is necessary to prepare a liquid containing exogenous genes, after the liquid is prepared, the injection head can be directly inserted into the container with the prepared liquid, and the main body can directly extract the liquid. In some embodiments, after the main body extracts the liquid, air bubbles can be expelled. In some embodiments, the liquid can be a resuspension containing Agrobacterium.

[0062] In step 1220, the first side of the plant leaf is positioned on a flexible object, and the injection head of the injection device pierces the plant leaf from the second side, creating a wound on the leaf surface. Alternatively, the first side of the plant leaf can be positioned on an operator's finger, allowing the operator to hold the plant leaf in place while using their other hand to insert the injection device. In some embodiments, since the back of the plant leaf has more stomata, the injection device can be inserted from the back of the plant leaf.

[0063] In step 1230, after the protrusion of the injection head pierces the plant leaf and the annular plane of the injection head closes the wound opening, the plant leaf adheres tightly to the annular plane of the injection head, forming a liquid space. This pushes the liquid in the body, allowing it to enter the plant leaf through the wound and seep into the leaf tissue. In some embodiments, pushing the liquid in the body needs to be done slowly.

[0064] In step 1240, once a wetting spot appears on the plant leaf, the injection of liquid into the plant leaf is complete, and the injection of liquid is stopped. In some embodiments, as the liquid enters the plant leaf, a translucent wetting spot appears on the plant leaf, and the area of ​​the wetting spot gradually expands with the injection of liquid. When the area of ​​the wetting spot can no longer expand, or when the area of ​​the wetting spot occupies the entire plant leaf, the injection of the infection solution is stopped.

[0065] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention.

Claims

1. An injection head for injecting liquid into plant leaves, comprising: A cylindrical body includes a first opening, a second opening, and a liquid passage. The first opening is located at a first end of the cylindrical body, the second opening is located at a second end of the cylindrical body, and the liquid passage is located inside the cylindrical body and connects the first and second openings for accommodating the passage of liquid. One or more first protrusions are provided at the second end of the cylinder for forming wounds on plant leaves; The second end of the cylinder is adapted to contact the plant leaves and utilize the plant leaves to form a liquid space separated from the outside of the cylinder between the damaged opening and the second end of the cylinder.

2. The injection head according to claim 1, wherein, During liquid injection, the pressure in the liquid space is greater than the external pressure.

3. The injection head according to claim 1, wherein, The second end of the cylinder includes an annular end face, which is adapted to adhere to the plant leaf when the first protrusion pierces into the plant leaf, thereby defining a liquid space isolated from the outside world.

4. The injection head according to claim 3, further comprising: One or more second protrusions are disposed at the second end of the cylinder; wherein the height of the second protrusion is less than or lower than the height of the first protrusion.

5. The injection head according to claim 4, wherein, The cylinder further includes: one or more partition bars disposed in the second opening to divide the second opening into multiple parts; wherein the first protrusion and / or the second protrusion are disposed on the partition bars and extend outward from the cylinder.

6. The injection head according to claim 4, wherein, The first protrusion is located at the center of the second opening, and the second protrusion is symmetrically located on both sides of the first protrusion.

7. The injection head according to claim 4, wherein, All or part of the first protrusion and / or the second protrusion are disposed on the annular end face.

8. The injection head according to claim 1, wherein, The liquid channel includes a first part and a second part, wherein the size of the second part gradually decreases from the first opening to the second opening.

9. The injection head according to claim 1, wherein, The angle of the end of the first protrusion is 50-60°, preferably 53-56°.

10. The injection head according to claim 9, wherein, The first protrusion includes a first surface and a second surface that are inclined, wherein the angle is the included angle between the first surface and the second surface.

11. The injection head according to claim 10, wherein, The height of the first protrusion is 2-5 times the thickness of the plant leaf.

12. An injection device for injecting liquid into plant leaves, comprising: The injection head as described in any one of claims 1-11.

13. A method for injecting a liquid into plant leaves, comprising: Liquid is drawn using an injection device; The first side of the plant leaf is placed on a flexible object, and the injection head of the injection device is inserted into the plant leaf from the second side of the plant leaf to form a wound on the plant leaf; As the protrusion of the injection head pierces into the plant leaf, the plant leaf adheres tightly to the injection head, forming a liquid space separated from the outside of the cylinder between the wound and the second end of the cylinder; and The liquid in the body is pushed, and the liquid enters the plant leaf through the wound.

14. The method according to claim 13, wherein, The second side of a plant leaf is the back of the plant leaf that is shaded.

15. The method of claim 13, further comprising: When a plant leaf develops a wet patch, or the area of ​​the wet patch can no longer expand, or the area of ​​the wet patch occupies the entire plant leaf, the flow of the infectious liquid stops.

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