Method for seed priming by using photosensitizer

Abstract

The invention discloses a treatment method for improving the germination rate and growth rate of plant seeds under normal and environmental stress conditions, and belongs to the field of seed initiators. In particular to a method for promoting seed germination and seedling growth, according to the method, a photosensitizer is used as an initiator to treat corn and wheat seeds, after initiation treatment, the seed vigor in normal, salt stress and drought environments can be remarkably improved, and seed germination and seedling growth are promoted. The method is simple to operate, low in cost, remarkable in promoting effect and easy to popularize.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of seed treatment, and relates to a treatment method for improving the germination rate and growth rate of plant seeds under normal and environmental stress conditions. BACKGROUND

[0002] Corn, rice and wheat are the world's three major staple crops, with the largest planting area, and are important food and feed crops in China. However, in the face of unstable climate, drought and salinization of the land seriously threaten the growth of crops, and in severe cases, cause the whole plant to die, resulting in a significant decrease in yield and quality. Seed germination is the most vulnerable and critical stage of plant life, and is extremely sensitive to environmental stress. Drought and salinity stress mainly inhibits and damages this process through osmotic effects, ion toxicity and oxidative damage. At the plant stage, environmental stress limits root extension and leaf expansion, causing slow or even stagnant plant growth, resulting in a significant decline in overall crop yield. Therefore, improving the germination vigor of crop seeds under environmental stress and improving crop growth and development under changing climate are key to addressing future climate challenges and achieving sustainable agricultural development.

[0003] So far, there have been various seed priming methods, but each method has its own shortcomings. For example, Chinese Patent No. CN120391139A discloses a seed priming method for improving the early disease resistance of pepper seeds. The seed activation solution in this method needs to be prepared in advance, the priming process is complex, and the cost of purchasing priming raw materials and operating equipment is high, which is not conducive to large-scale industrial production. Chinese Patent No. CN120513731A discloses an intelligent seed priming device for agricultural seeds, which improves the mixing uniformity of seeds and substrate in the barrel by rotating the barrel. However, this device has the disadvantages of high equipment development, production and maintenance costs, and limited application range. Chinese Patent No. CN119908367A provides a seed germination and growth priming liquid containing nano-zinc oxide particles. This method has the risk of residual priming agent polluting farmland and groundwater. Chinese Patent No. CN119453208A discloses a method of applying dihydroquercetin to wheat seed priming. The extraction cost of dihydroquercetin in this method is high, the market price is high, the marginal profit for use in field crops is low, and it may affect the balance of soil microbial communities and soil fertility.

[0004] To solve the above problems, the application provides a method for seed priming by using photosensitizer. The photosensitizer can level jump under light irradiation, and transfer its energy to the surrounding oxygen molecules, thereby producing reactive oxygen species (ROS). ROS acts as a multifunctional signal molecule in various cellular processes of plants, and can regulate plant growth and development and stress response. The photosensitizer is low in price, can penetrate the cell membrane as a small molecule, has a relatively high ROS quantum yield, and is low in dark toxicity. As a seed priming agent, the photosensitizer can effectively improve the growth speed of crop seedlings in a suitable environment, and improve the resistance to drought and salt stress during seed germination and growth, and has great application potential in seed priming. SUMMARY

[0005] To improve the seed germination and growth performance of crops such as corn and wheat in normal and stress environments, the application uses photosensitizer as a seed priming agent, and the specific operation is as follows: First, a 10-100 mg / L photosensitizer aqueous solution is prepared, then corn and wheat seeds are soaked in a 1% sodium hypochlorite solution for 15 minutes for disinfection, washed with water for three times, then soaked in the photosensitizer solution, the seed (g) : soaking liquid (mL) = 1:5, placed in a 20-25℃ dark place, appropriately stirred for uniform soaking, soaked for 12-24 hours, then the soaked seeds are irradiated under sunlight or a sunlight simulation device for 12-20 hours and stored.

[0006] The application uses a photosensitizer aqueous solution of a certain concentration to prime corn and wheat seeds, which can significantly improve the germination rate, seedling growth vigor and biomass accumulation of the seeds in suitable, drought and salt stress environments, significantly reduce the accumulation of active oxygen in the seeds and seedlings, significantly reduce the malondialdehyde content of the plants in stress environments, and reduce the oxidative stress and toxic effects of stress environments on crops.

[0007] The technical scheme of the application is low in cost, the reagent is safe and easy to obtain, the operation process is simple and convenient, no complex synthesis process is needed, the promoting effect is obvious, and the application is easy to industrialize, thereby providing a new technical guide for expanding the cultivation area, improving the quality and yield of agricultural products, and reducing the natural disaster losses of farmers. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 Fig. 1 is a schematic diagram of the effect of different concentrations of photosensitizer treatment on the root and stem length of Zhengdan 958 corn seedlings in a normal environment in the application; Figure 2 Fig. 2 is a schematic diagram of the effect of different concentrations of photosensitizer treatment on the root and stem length of Zhengdan 958 corn seedlings under salt stress in the application; Figure 3The figure is the effect of 40 mg / L photosensitizer treatment in the present application on the germination rate of Zhengdan 958 corn seeds in moderate drought soil. Figure 4 The figure is the effect of 40 mg / L photosensitizer treatment in the present application on the plant height of Zhengdan 958 corn in moderate drought soil. Figure 5 The figure is the effect of different concentrations of photosensitizer treatment in the present application on the root and stem length of Xiaoyan 22 wheat seedlings under normal environment. Figure 6 The figure is the effect of different concentrations of photosensitizer treatment in the present application on the root and stem length of Xiaoyan 22 wheat seedlings under salt stress. Figure 7 The figure is the effect of deionized water and 40 mg / L photosensitizer treatment in the present application on the leaf MDA content of Zhengdan 958 corn plants in moderate drought soil. DETAILED DESCRIPTION

[0009] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined purpose, the specific embodiments, structures, features and effects according to the present application are described in detail below in combination with the drawings and preferred embodiments.

[0010] Example 1 Select 800 uniform-sized corn seeds (Zhengdan 958) and disinfect them in 1% sodium hypochlorite solution for 15 minutes, rinse them with deionized water for 3 times, and immerse them in 10, 20, 30, 40, 60, 80, 100 mg / L photosensitizer aqueous solution respectively, 100 seeds for each concentration, seed (g): soaking liquid (mL) = 1:5, place them in a dark place at 20-25°C for 24 hours, and appropriately stir them to soak uniformly, then irradiate the soaked seeds under sunlight or xenon lamp for 20 hours, and the light intensity is 36-40 mW / cm 2 .

[0011] Sow the corn seeds in a 10 cm x 10 cm culture dish containing a layer of filter paper, 20 seeds per dish, irrigate each dish with 3.5 mL deionized water to simulate normal environment, and supplement deionized water every day, then measure the root and stem length of the seedlings after 6 days of culture.

[0012] Effect evaluation: Referring to Figure 1 , Figure 1 The figure is the root and stem length of Zhengdan 958 corn seedlings under normal environment, and different concentrations of photosensitizer initiation treatment all have a promoting effect on the root and stem length of the seedlings, among which the seed of 30 mg / L initiation treatment grows most significantly, the stem length is increased by 20.01%, and the root length is increased by 16.08%.

[0013] Example 2 Each dish irrigated 3.5 mL of 100 mmol / L sodium chloride solution to simulate salt stress environment, daily supplement of sodium chloride solution, the rest is the same as example one.

[0014] Effect evaluation: Reference Figure 2 , Figure 2 The length of the root and stem of Zhengdan 958 corn seedlings under salt stress environment is shown, and the photosensitizer priming treatment has a significant improvement effect on the length of the root and stem of the seedlings at some concentrations, among which the 40 mg / L priming treatment has the most significant improvement, with the stem length increasing by 25.9% and the root length increasing by 17.1%.

[0015] Example three Select uniform size corn seeds (Zhengdan 958), disinfect in 1% sodium hypochlorite solution for 15 minutes, rinse 3 times with deionized water, respectively soak in deionized water and 40 mg / L photosensitizer solution, seed (g): soaking liquid (mL)=1:5, place in 20-25℃ dark place for 24 hours, appropriate stirring to soak evenly, place the soaked seeds under sunlight or xenon lamp for 20 hours, the light intensity is 36-40 mW / cm 2 .

[0016] The deionized water treated corn seeds are sown in the seedling hole, and the soil of the seedling hole is normally (60-80% relative humidity) treated, the seeds treated with deionized water and 40 mg / L photosensitizer solution are sown in the seedling hole treated with moderate drought (40-50% relative humidity), water is supplemented daily to maintain soil humidity, and after the seeds germinate, sunlight or simulated sunlight is supplemented, the germination rate and plant height of seeds of different treatments are counted daily, and the plants are harvested after 2 weeks.

[0017] Effect evaluation: Reference Figure 3 , Figure 4 , Figure 3 , 4 The germination rate and plant height of Zhengdan 958 corn in normal and moderate drought soil are shown, respectively, under moderate drought, the germination rate of corn seeds treated with photosensitizer is significantly improved, and the final germination rate is increased by 20.41%; in addition, the growth rate of corn seeds treated with photosensitizer is also significantly improved, and the plant height of 14-day-old plants is increased by 54.21% compared with the water treatment group.

[0018] Example four Select uniform size of wheat seeds (Xiaoyan 22) 800, in 1% sodium hypochlorite solution for 15 minutes, washed with deionized water 3 times, respectively, in 10, 20, 30, 40, 60, 80, 100 mg / L photosensitizer aqueous solution, each concentration of 100 seeds, seeds (g): soaking liquid (mL) = 1:5, placed in 20-25℃ dark for 24 hours, appropriate stirring to soak evenly, then, the seeds soaked in sunlight or xenon lamp irradiation 12 hours, the intensity of light is 36-40 mW / cm 2 .

[0019] Wheat seeds were sown in a 10 cm x 10 cm culture dish with a layer of filter paper, 20 seeds per dish, 3.5 mL deionized water was poured into each dish to simulate normal environment, deionized water was added daily, after 7 days of culture, the length of seedling root and stem was measured.

[0020] Effect evaluation: Referring to Figure 5 , Figure 5 The length of Xiaoyan 22 wheat seedling root and stem under normal environment is shown, different concentrations of photosensitizer initiation treatment can improve the length of seedling root and stem, but not significantly; some concentrations of treatment can significantly improve the length of root, among which the length of seedling stem treated with 30 mg / L photosensitizer is improved by 39.46%, which is the most significant.

[0021] Example five 3.5 mL of 100 mM sodium chloride solution was poured into each dish to simulate salt stress environment, and sodium chloride solution was added daily, and the rest was the same as example four.

[0022] Effect evaluation: Referring to Figure 6 , Figure 6 The length of Xiaoyan 22 wheat seedling root and stem under salt stress is shown, different concentrations of photosensitizer initiation treatment can improve the length of seedling root and stem, among which the length of seedling stem treated with 30 mg / L photosensitizer is improved by 48.30%, and the improvement of root length is not significant.

[0023] Example six The variety of this example is Zhengdan 958 corn, and the plant cultivation method is the same as that of example three. The malondialdehyde content of plant leaves is determined in this example, and the specific steps are as follows: Step one, take 14-day-old plant stems as samples, wash the samples with deionized water, and grind them into fine powder in liquid nitrogen; Step two, accurately weigh the fine powder according to the ratio of weight: volume = 1:4, add the corresponding extraction solution, homogenize at low temperature, centrifuge at 3500-4000 rpm for 10 min, and take the supernatant for measurement; Step three, use the test box of Nanjing Jiancheng Bioengineering Institute to detect. Use Varioskan Flash full wavelength multifunctional enzyme label instrument to detect absorbance and calculate malondialdehyde content according to corresponding formula.

[0024] Effect evaluation: Refer to Figure 7 , Figure 7 As shown in Fig. 6, under moderate drought stress, the malondialdehyde content of the seed leaves of Zhengdan 958 was significantly reduced by 11.51% compared with the water treatment.

[0025] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution range of the present application. Any modification, equivalent change and modification of the above embodiments made according to the technical essence of the present application still belong to the scope of the technical solution of the present application.

Claims

1. A method of promoting seed germination, characterized by, The method comprises the following steps: Step 1: preparing plant seeds and initiators; Step 2: soaking the plant seeds with the initiators; Step 3: placing the plant seeds in an initiation container, adding initiators and stirring to make the plant seeds fully contact with the initiators; Step 4: initiating the initiation container in a dark condition; Step 5: after the initiation is completed, irradiating the crop seeds under a light source containing a photosensitive wavelength and drying.

2. A method of promoting seed germination according to claim 1, wherein, In step 1, the initiator is a photosensitizer capable of generating active oxygen, and the concentration of the initiator is 0-100 mg / L.

3. The photosensitizer of claim 2, wherein The photosensitizer used includes all substances capable of generating active oxygen (ROS) under light irradiation, including but not limited to porphyrin photosensitizers, cyanine photosensitizers, methylene blue, BODIPY, etc.

4. The method for promoting seed germination according to claim 1, wherein In step 2, the ratio of seeds (g) to initiation liquid (mL) is 1:1-1:

100.

5. The method for promoting seed germination according to claim 1, wherein In step 3, the initiation container is placed in a dark environment for 0-48 hours.

6. The method of claim 1, wherein the seed is a seed of a crop plant. In step 4, after the initiation is completed, the crop seeds are taken out of the container, irradiated under a light source containing a photosensitive wavelength of the photosensitizer, and dried.

Images