Pseudomonas bacteria, microbial inoculum and application of pseudomonas bacteria and microbial inoculum

Abstract

The invention provides a pseudomonas bacterium, a microbial inoculum and application of the pseudomonas bacterium and the microbial inoculum, and belongs to the technical field of microorganisms. The invention provides a strain of Pseudomonas aagonensis JF3, and the preservation number of the Pseudomonas aagonensis JF3 is CGMCC (China General Microbiological Culture Collection Center) No. 34848. In the invention, the pseudomonas bacterium JF3 is a growth-promoting bacterium screened from rhizosphere soil of rhizoma corydalis, has the capabilities of fixing nitrogen, dissolving phosphorus and producing siderophores, can be used as a growth promoting agent to promote the growth of overground parts of rhizoma corydalis seedlings, and particularly has a remarkable effect of promoting accumulation of total alkaloid content in rhizoma corydalis tubers; the method can be used for artificial cultivation of the corydalis tuber, provides a theoretical basis for improving the yield and quality of the corydalis tuber, and has important guiding significance for reasonably and effectively utilizing microorganisms to improve the quality and yield of Qinshi medicine-corydalis tuber.

Description

Technical Field

[0001] This invention belongs to the field of microbial technology, and in particular relates to a strain of Pseudomonas bacteria, a bacterial agent, and their applications. Background Technology

[0002] Corydalis yanhusuo (W.T. Wang) is a highly effective herb for promoting blood circulation, removing blood stasis, regulating qi, and relieving pain, especially renowned for its analgesic properties. Corydalis yanhusuo thrives in warm, humid, and cool climates, and is best cultivated in humus-rich, loose, well-drained sandy loam. The size of the tuber is a crucial indicator of its quality; larger tubers indicate higher quality and command higher market prices. Corydalis yanhusuo tubers contain alkaloids with strong analgesic, sedative, and hypnotic effects; higher alkaloid content in the tuber indicates superior quality. Rhizosphere microorganisms are the plant's second genome, playing a vital role in plant growth and development. Utilizing rhizosphere growth-promoting bacteria to enhance the growth of Corydalis yanhusuo and increase the content of its key active ingredient, total alkaloids, is a key technical challenge that needs to be addressed. Summary of the Invention

[0003] The purpose of this invention is to provide a strain of Pseudomonas bacteria, a fungal agent, and their applications. The Pseudomonas bacteria and fungal agent of this invention can both promote the growth of Corydalis rhizome and increase the content of total alkaloids, the key active ingredient of Corydalis rhizome.

[0004] This invention provides a strain of Pseudomonas atagonensis JF3, with accession number CGMCC No. 34848.

[0005] The present invention also provides a bacterial agent comprising the Pseudomonas spp. bacteria JF3 described in the above-described scheme.

[0006] Preferably, the bacterial agent comprises a bacterial suspension; the OD of the bacterial suspension... 600 =0.8.

[0007] The present invention also provides the application of the Pseudomonas bacteria JF3 described in the above-described scheme or the bacterial agent described therein in promoting plant growth and / or improving plant quality.

[0008] Preferably, the promotion of plant growth includes promoting the growth of plant seedlings and / or promoting the growth of plant tubers; the plant includes at least one of Corydalis yanhusuo, Arabidopsis thaliana, and Panax quinquefolius.

[0009] Preferably, the promotion of plant seedling growth includes at least one of 1) to 3):

[0010] 1) Promotes the growth of the above-ground parts of plant seedlings;

[0011] 2) Promotes the length of the underground part of plant seedlings;

[0012] 3) Increase the fresh weight and / or dry weight of the whole plant seedling;

[0013] The promotion of plant tuber growth includes at least one of (1) to (3):

[0014] (1) Increase the transverse diameter of plant tubers;

[0015] (2) Increase the longitudinal diameter of plant tubers;

[0016] (3) Increase the fresh weight and / or dry weight of plant tubers.

[0017] Preferably, improving plant quality includes increasing the total alkaloid content in Corydalis tubers.

[0018] Preferably, the promotion of plant growth is achieved by nitrogen fixation, dissolution of inorganic phosphorus, and / or secretion of siderophores by Pseudomonas bacteria JF3.

[0019] The present invention also provides a method for promoting plant growth and / or improving plant quality, comprising the following steps:

[0020] Apply the Pseudomonas spp. bacteria JF3 or the bacterial agent described in the above scheme to the plant seedlings.

[0021] Preferably, the method of application includes root irrigation.

[0022] This invention provides a strain of *Pseudomonas atagonensis* JF3, with accession number CGMCC No. 34848. In this invention, *Pseudomonas atagonensis* JF3 is a growth-promoting bacterium screened from the rhizosphere soil of *Corydalis yanhusuo*. *Pseudomonas atagonensis* JF3 possesses nitrogen-fixing, phosphorus-solubilizing, and siderophore-producing abilities. As a growth promoter, it can promote the aboveground growth of *Corydalis yanhusuo* seedlings, especially significantly promoting the accumulation of total alkaloids in *Corydalis yanhusuo* tubers. It can be used in the artificial cultivation of *Corydalis yanhusuo*, providing a theoretical basis for improving the yield and quality of *Corydalis yanhusuo*. It has important guiding significance for the rational and effective utilization of microorganisms to improve the quality and yield of *Corydalis yanhusuo*, a traditional Chinese medicine from Qin.

[0023] Biological Preservation Instructions

[0024] Pseudomonas atagonensis JF3 was deposited on June 11, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCCNo. 34848. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 Phylogenetic tree of JF3;

[0027] Figure 2 The colony characteristics of JF3 bacteria;

[0028] Figure 3 Gram staining results for JF3 bacteria;

[0029] Figure 4 The nitrogen-fixing properties of JF3;

[0030] Figure 5 The phosphorus solubility characteristics of JF3 are shown; where A is JF3 and B is the control of JF3 on LB medium.

[0031] Figure 6 The siderophoretic characteristics of JF3 are shown; where A is JF3 and B is the control of JF3 on LB medium.

[0032] Figure 7 The IAA characteristics of JF3 are shown; JF3 is on the left and the control is on the right.

[0033] Figure 8 The image shows a comparison of Arabidopsis thaliana growth after treatment with JF3 bacterial culture and a control group; where A is the JF3 treatment group and B is the 10 mg SO4 control group.

[0034] Figure 9 The image shows a comparison of whole-plant American ginseng seedlings from the JF3 treatment group and the TSA control group after 60 days of root irrigation treatment; where A is the JF3 treatment group and B is the TSA control group.

[0035] Figure 10 The results of the verification of the growth-promoting effect of JF3 are shown in the figure. Among them, A is a comparison of the growth of multiple pots, with the six pots on the left showing the growth status of seedlings in the JF3 treatment group and the six pots on the right showing the growth status of seedlings in the control group TSA treatment group; B is a comparison of the growth of individual pots, with the left showing the growth status of seedlings in the JF3 treatment group after 30 days of root irrigation and the right showing the growth status of seedlings in the control group TSA treatment group after 30 days of root irrigation.

[0036] Figure 11 The image shows a comparison of whole-plant corydalis seedlings in the experimental group and the TSA control group after 30 days of root irrigation treatment; where A is the TSA control group and B is the JF3 bacteria treatment group.

[0037] Figure 12 Phenotypic comparison of Corydalis seedlings and tubers in the JF3-treated group and the TSA control group after 30 days of root irrigation treatment;

[0038] Figure 13 A comparison of the total alkaloid content in the tubers of Corydalis rhizome after 30 days of root irrigation treatment with JF3 bacteria and TSA control group. Detailed Implementation

[0039] This invention provides a strain of Pseudomonas atagonensis JF3, with accession number CGMCC No. 34848.

[0040] In this invention, the *Pseudomonas* bacterium JF3 was screened from the rhizosphere soil of *Corydalis yanhusuo*, a traditional producing area in Zhejiang. It is generally believed that *Corydalis yanhusuo* from Zhejiang has larger tubers, superior quality, and commands a higher market price compared to its main producing area in Shaanxi. Isolating rhizosphere microorganisms from *Corydalis yanhusuo* from Zhejiang and screening for microorganisms that promote tuber growth and development is of great significance for improving the quality of *Corydalis yanhusuo* from Shaanxi.

[0041] In this invention, the Pseudomonas bacteria JF3 has nitrogen-fixing, strong phosphorus-solubilizing, and siderophore-producing abilities; the Pseudomonas bacteria JF3 has a significant promoting effect on the growth of the aboveground parts and tubers of Corydalis seedlings, effectively promoting the growth of Corydalis seedlings, and significantly promoting the accumulation of total alkaloids in Corydalis tubers.

[0042] In this invention, the nucleotide sequence of the 16S rDNA of the Pseudomonas bacteria JF3 is shown in SEQ ID NO.1.

[0043] In this invention, the colonies of the *Pseudomonas* genus JF3 are bright yellow, smooth, and round with a slightly raised center. After Gram staining, they are Gram-negative bacteria, and under an oil immersion microscope (100x magnification), the strain is a rod-shaped bacterium.

[0044] In this invention, the Pseudomonas bacterium JF3 does not secrete auxin.

[0045] The present invention also provides a bacterial agent comprising the Pseudomonas spp. bacteria JF3 described in the above-described scheme.

[0046] In one embodiment, the bacterial agent comprises a bacterial suspension; the OD of the bacterial suspension... 600 =0.8.

[0047] As one embodiment, the method for preparing the bacterial suspension includes the following steps:

[0048] The *Pseudomonas* spp. JF3 was inoculated into TSA liquid medium and cultured with shaking. The resulting bacterial suspension was adjusted to OD0. 600 =0.8; the temperature of the shaking culture is 25℃; the rotation speed of the shaking culture is 200rpm; the shaking culture time is 1d.

[0049] The present invention also provides the application of the Pseudomonas bacteria JF3 described in the above-described scheme or the bacterial agent described therein in promoting plant growth and / or improving plant quality.

[0050] In one implementation, the promotion of plant growth includes promoting the growth of plant seedlings and / or promoting the growth of plant tubers; the plant includes at least one of Corydalis yanhusuo, Arabidopsis thaliana, and Panax quinquefolius.

[0051] As one implementation, the promotion of plant seedling growth includes at least one of 1) to 3):

[0052] 1) Promotes the growth of the above-ground parts of plant seedlings;

[0053] 2) Promotes the length of the underground part of plant seedlings;

[0054] 3) Increase the fresh weight and / or dry weight of the whole plant seedling;

[0055] The promotion of plant tuber growth includes at least one of (1) to (3):

[0056] (1) Increase the transverse diameter of plant tubers;

[0057] (2) Increase the longitudinal diameter of plant tubers;

[0058] (3) Increase the fresh weight and / or dry weight of plant tubers.

[0059] As one implementation method, improving plant quality includes increasing the total alkaloid content in Corydalis tubers.

[0060] In one implementation, the promotion of plant growth is achieved through nitrogen fixation, dissolution of inorganic phosphorus, and / or secretion of siderophores by Pseudomonas bacteria JF3.

[0061] The present invention also provides a method for promoting plant growth and / or improving plant quality, comprising the following steps:

[0062] Apply the Pseudomonas spp. bacteria JF3 or the bacterial agent described in the above scheme to the plant seedlings.

[0063] As one implementation method, the application includes root irrigation.

[0064] As one implementation, the amount of the root irrigation application, calculated as a bacterial suspension containing Pseudomonas spp. bacteria JF3, is 30 mL per plant.

[0065] To further illustrate the present invention, the following detailed description, in conjunction with the accompanying drawings and embodiments, describes a strain of Pseudomonas bacteria, its inoculum, and its applications, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0066] Example 1

[0067] I. Strains Isolation and Screening

[0068] Preparation of TSA solid medium: Weigh 15g tryptone, 5g soybean peptone, 5g sodium chloride, and 15g agar, add water to a final volume of 1L, adjust the pH to 7.3±0.2, and autoclave at 121℃ for 15min. The liquid medium used in the experiment was the solid medium formula without agar.

[0069] In the Corydalis cableway producing area of ​​Hexie Village, Mazhai Town, Dongyang City, Jinhua, Zhejiang Province, a five-point sampling method was used, selecting 20 Corydalis plants at each point. The Corydalis plants were dug up along with the soil, and large clumps of soil around the tubers were shaken off, leaving about 1 mm of soil adhering to the surface of the tubers. Then, an appropriate amount of undamaged tubers were selected and placed in a sterile plastic bottle. The soil adsorbed on the surface of the tubers was washed off with about 100 mL of PBS buffer. The washing was repeated twice. The soil suspension was placed in a 250 mL Erlenmeyer flask and cultured on a shaker (25℃, 120 r / min) for 1 h, followed by sonication at 140 kHz for 40 s.

[0070] Take 1 mL of soil suspension and dilute it stepwise to 10. -4 Dilute 200 μL to 10 times the volume. -4 A soil suspension of a certain concentration was spread onto TSA medium. After the surface of the medium dried, it was inverted and incubated in a 25°C incubator for 16–18 hours. Newly grown single colonies were picked and cultured until no new colonies grew. The grown bacterial colonies were then transferred to the corresponding 1 mL liquid medium and incubated overnight on a shaker (200 rpm, 25°C). After multiple streak isolation and purification in three zones, a pure bacterial culture was obtained. Based on the morphology and characteristics of the bacteria on the medium, preliminary classification and removal of duplicates were performed. The purified bacteria were named JF3.

[0071] II. Strain Identification

[0072] 1. Identification and preservation of JF3 strain

[0073] Ten replicates of JF3 bacterial culture cultured overnight on a shaker were amplified by PCR using primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3', SEQ ID NO.2) and 1492R (5'-TACGGTTACCTTGTTACGACTT-3', SEQ ID NO.3) and then sent for identification. The PCR reaction system (25 μL) consisted of 1 μL of each primer, 1 μL of JF3 bacterial culture, 12.5 μL of 2×Taq PCR Mix, and ddH2O to a final volume of 25 μL. The PCR reaction conditions were as follows: denaturation at 94℃ for 3 min, followed by denaturation at 94℃ for 25 s, annealing at 55℃ for 25 s, extension at 72℃ for 1.5 min, for 35 cycles, and a final extension at 72℃ for 5 min. Five μL of the extracted PCR product was electrophoresed on a 1% agarose gel. The PCR product with a bright band at 1500 bp was sent to BGI (Beijing Liuhe BGI Genomics Co., Ltd.) for sequencing. The sequencing results were compared with those from the ezbiocloud bacterial database (EzBioCloud.net | Search about Bacteria or Archaeea) and NCBI (…). www.ncbi.nlm.nih.gov The JF3 bacterial culture was compared with that of 800 μL of 50% sterile glycerol. The mixture was then stored at -80°C. Comparison with the ezbiocloud bacterial database showed that JF3 had the highest similarity (99.70%) to the known type species *Pseudomonas atag onensis*, PS14. For samples showing high homology with the NCBI database, a phylogenetic tree was constructed using MEGA-X. (See [link to documentation]). Figure 1 The Bootstrap value is set to 1000, while the others are default values. Figure 1

[0074] 2. Morphological identification of strains

[0075] Based on the colony characteristics of the isolated strain after purification and culture, such as... Figure 2 As shown in Table 1, the bacterial colonies are bright yellow, smooth, and round with a slightly raised center. After Gram staining, they are Gram-negative bacteria. Under an oil immersion microscope (100x magnification), the strain is a rod-shaped bacterium. Figure 3 (As shown).

[0076] Table 1. Colony morphology of JF3

[0077] serial number shape color Concave and convex Other features JF3 round Bright yellow convex Smooth surface

[0078] 3. Physiological and biochemical identification

[0079] The physiological and biochemical analysis of JF3 bacteria was performed in accordance with the "Handbook for Systematic Identification of Common Bacteria": Gram staining, carbohydrate decomposition, VP determination, methyl red, citrate utilization, starch hydrolysis, indole, catalase, oxidase, hydrogen sulfide, and gelatin liquefaction experiments. The results are shown in Table 2.

[0080] Table 2 Physiological and biochemical characteristics of JF3

[0081]

[0082] Experimental Example 1

[0083] Functional identification of strains

[0084] 1. Nitrogen fixation

[0085] Nitrogen fixation of JF3 bacteria was analyzed using Ashby nitrogen-free medium. Based on the characteristics of Ashby medium, only nitrogen-fixing strains can grow normally on this medium. The activated JF3 bacterial suspension (OD200) was then... 600 =0.5) was added to Ashby liquid medium (1:50 / v:v), and cultured on a shaker at 25℃ and 200rpm for 1 day. The bacterial culture was then streaked onto Ashby solid medium and continuously cultured three times. If the strain grew normally, it was considered to have nitrogen-fixing activity. The results showed that JF3 bacteria grew normally, indicating that this strain has nitrogen-fixing activity (5 replicates). Figure 4 As shown.

[0086] 2. Phosphorus dissolution

[0087] Phosphate solubilization of JF3 bacteria was analyzed using PVK phosphate-solubilizing medium (10g glucose, 0.5g (NH4)2SO4, 0.03g manganese sulfate monohydrate, 0.03g FeSO4·7H2O, 0.3g sodium chloride, 0.3g magnesium sulfate heptahydrate, 0.3g KCl, 2.5g Ca3(PO4)2, 15g agar, diluted to 1L with water (pH = 7.4 ± 0.2), autoclaved at 121℃ for 15min). 2μL of activated JF3 bacterial suspension (OD) was collected using the spot inoculation method. 600 =0.5), inoculated onto PVK phosphate-solubilizing medium, and incubated in the dark at 25℃ for 7 days. The presence of a transparent phosphate-solubilizing zone around the colony was observed to determine whether the strain possessed phosphate-solubilizing activity. The ratio of the transparent zone diameter (D) to the colony diameter (d) indicated the strength of the strain's activity. A blank LB solid medium (10g tryptone, 5g yeast extract, 10g sodium chloride, 15g agar, diluted to 1L with water, autoclaved at 121℃ for 15min) was used as the control group, with 5 replicates. The results showed that JF3 bacteria formed a transparent zone around their colonies, and the average phosphate-solubilizing zone ratio (D / d) was 5.954, indicating that this bacterium has a strong phosphate-solubilizing (inorganic phosphorus) activity. Figure 5 As shown in Table 3.

[0088] Table 3. Determination of phosphorus solubility diameter in strain JF3

[0089] strain number 1 (D / d, cm) 2 (D / d, cm) 3 (D / d, cm) 4 (D / d, cm) 5 (D / d, cm) JF3 7 6.5 5.3 5.75 5.22

[0090] 3. Role as a carrier for iron production

[0091] The siderophoretic activity of JF3 bacteria was analyzed using CAS (Croatian Blue) medium (purchased from Qingdao Haibo Biotechnology Co., Ltd., catalog number HB9132; 10.87 g was weighed, added to 1000 mL of sterile water, boiled until completely dissolved, then autoclaved at 121℃ for 15 min, mixed well, and poured into plates). 2 μL of activated JF3 bacterial suspension (OD) was collected using the spot inoculation method. 600 =0.5), inoculated onto CAS solid medium, and incubated in the dark at 25℃ for 7 days. The presence of a yellow halo around the colony was observed. The ratio of the halo diameter (D) to the colony diameter (d) indicates the strength of the strain's ability, determining whether the strain has siderogenic activity. A blank LB solid medium (10g tryptone, 5g yeast extract, 10g sodium chloride, 15g agar, diluted to 1L with water, autoclaved at 121℃ for 15min) was used as the control group, with 5 replicates. The results showed that JF3 bacteria formed a yellow halo around their colonies, and the average halo ratio (D / d) was 4.62, indicating that JF3 bacteria have a strong siderogenic activity. Figure 6 As shown in Table 4.

[0092] Table 4. Determination of the diameter of the yellow halo around the siderophore produced by strain JF3

[0093] strain number 1 (D / d, cm) 2 (D / d, cm) 3 (D / d, cm) 4 (D / d, cm) 5 (D / d, cm) JF3 5.4 4.6 4.4 4.6 4.1

[0094] 4. Detection of indole-3-aceticacid (IAA)

[0095] Qualitative analysis of IAA production in JF3 bacteria was performed using the Salkowski colorimetric method. Single colonies of activated JF3 bacteria were inoculated into LB liquid medium without L-tryptophan (purchased from Shanghai Yuanye Biotechnology Co., Ltd., catalog number S20082) and LB liquid medium containing L-tryptophan (1.0 g / L), respectively, and cultured at 25℃ and 200 rpm for 1 day. Using the L-tryptophan-free LB liquid fermentation medium as a control, the fermentation broth was centrifuged at 8000 rpm for 10 min, and the supernatant was mixed with 2 mL of Salkowski colorimetric solution (purchased from Feijing Biotechnology Co., Ltd., catalog number PH1941) and incubated in the dark for 30 min. The color of the solution was observed to determine whether the strain had the ability to produce IAA. The results showed that the solution color did not turn red before and after treatment with JF3 bacteria, indicating that JF3 bacteria did not produce IAA, so further quantitative analysis was not performed. Figure 7 As shown in Table 5.

[0096] Table 5 JF3 Production IAA Characteristic Verification

[0097] strain number Contains L-tryptophan L-tryptophan-free JF3 — —

[0098] Note: + indicates a positive reaction; - indicates a negative reaction.

[0099] Experimental Example 2

[0100] Evaluation of the growth-promoting effect of strains in Arabidopsis thaliana, a model plant

[0101] 1. Cultivation of Arabidopsis thaliana

[0102] A small amount of Arabidopsis thaliana seeds stored at 4°C were placed in a microcentrifuge tube. The seeds were initially disinfected with a 70% ethanol solution (5 min), followed by further disinfection with a 2% NaClO solution (7 min). The seeds were then washed six times with sterile water to ensure complete removal of microorganisms from the seed surface. The seed suspension was spotted onto 1 / 2 MS solid medium (2.22 g / L MS + 10 g / L sucrose + 8 g / L agar) using a blue sterile pipette tip. The culture dish was sealed with sealing film and vernalized in the dark for 48 h (4°C). Afterward, the culture was transferred to a 25°C light / dark (16 h / 8 h) artificial climate chamber for further cultivation for approximately 2–5 days.

[0103] 2. Bacterial solution treatment

[0104] The identified JF3 bacteria (Pseudomonas atagonensis) were inoculated into TSA liquid medium and cultured at 25°C with shaking at 200 rpm for 1 day. After centrifugation at 1500 × g for 15 min at room temperature, the supernatant was removed. A 10 mM magnesium sulfate solution was prepared and filtered through a 0.22 μm microporous membrane to resuspend the JF3 cells. The OD value was adjusted to... 600 =1, used for subsequent staining. The control treatment was 10mM magnesium sulfate solution filtered through a 0.22μm microporous membrane.

[0105] 3. Sample selection and processing

[0106] Take a 1 / 2 MS solid culture dish and place 6-8 Arabidopsis thaliana seedlings with similar growth conditions (root length 1 cm and no lateral roots) in each dish. Pipette 20 μL of JF3 inoculation suspension onto the roots of each seedling. The control group consists of 20 μL of 10 mM magnesium sulfate solution. Each group is repeated three times. All groups are incubated in a light incubator. After 6 days, root length is measured and the number of lateral roots is counted.

[0107] 4. Results Analysis

[0108] Figure 8 The image shows a comparison of Arabidopsis thaliana growth after treatment with JF3 bacterial solution and a control group (A is the JF3 treatment group, B is the 10 mg SO4 control group). It is clearly shown that the JF3-treated Arabidopsis thaliana had more lateral root branches compared to the control group, as shown in Table 6. Data analysis using IBM SPSS Statistics 27 showed a significant difference in the number of lateral roots between the JF3 treatment group and the control group (p < 0.05), indicating that JF3 can significantly promote the growth and development of lateral roots in Arabidopsis thaliana.

[0109] Table 6. Comparison of taproot length and lateral root number in Arabidopsis thaliana after 6 days of JF3 treatment and the 10 mg SO4 control group (n=8)

[0110]

[0111] Experimental Example 3

[0112] Evaluation of the growth-promoting effect of bacterial strains in potted American ginseng seedlings

[0113] 1. Root irrigation with bacterial solution

[0114] The identified JF3 bacteria (Pseudomonas atagonensis) were inoculated into TSA liquid medium and cultured at 25°C with shaking at 200 rpm for 1 day. The resulting bacterial suspension was then adjusted to OD200. 600 = Approximately 0.8, used for subsequent root irrigation with bacterial solution, while the control treatment was TSA liquid culture medium treated in the same way.

[0115] 2. Sample selection and processing

[0116] Select about 8-10 two-year-old American ginseng seedlings and pot them (before planting, all American ginseng seedlings were disinfected with 75% ethanol, and the soil used was sterilized at 121℃ for 15 minutes. One American ginseng seedling was planted in each pot and the same weight of sterilized soil was added). After all the seedlings have grown healthily, they were divided into groups, and 3 American ginseng seedlings with the same growth and health status were selected from each group and labeled as JF3 and TSA groups.

[0117] 3. Verification of the effect of promoting fertility

[0118] On the 7th day after the American ginseng seedlings were planted in pots (when growth was stable), the seedlings were treated with 50 mL / plant of root-drenching bacterial solution. An equal volume of sterile TSA liquid culture medium was used as a control group. The seedlings treated with root drenching were placed in a sterile light incubator for natural growth. During the growth period, they were watered with sterile water every 2 days, with day and night temperatures of 22℃ and 18℃ respectively, a light duration of 14 hours, and a darkness duration of 10 hours. After 60 days of root drenching treatment, the above-ground parts (plant height), underground parts (root length), whole plant fresh weight, and stem circumference of the American ginseng plants were measured. (Above-ground part: Use a ruler to measure the height from the top of each American ginseng plant to the surface of the soil in the flowerpot; Below-ground part: After measuring the above-ground part of the American ginseng plant, cut off the above-ground part with scissors, dig out the underground part of the plant, and then measure the length of the underground part with a ruler; Stem circumference: Mark the thickest part of the stem with a thin thread, then unfold and measure its length; Fresh weight determination: After washing and drying the American ginseng, weigh the whole plant.)

[0119] 4. Results Analysis

[0120] Figure 9 The figure shows a comparison of the whole plant of American ginseng seedlings in the JF3 treatment group and the TSA control group after 60 days of root drenching treatment (A is the JF3 treatment group, B is the TSA control group). As can be seen from the figure, the American ginseng seedlings treated with JF3 bacterial solution showed better overall growth than those treated with TSA medium alone. Observation showed that the aboveground parts of the seedlings treated with bacterial solution were longer and the stem circumference was thicker than those in the TSA medium treatment group. Table 7 shows a comparison of the aboveground and underground part lengths, whole plant fresh weight, and stem circumference of American ginseng seedlings in the JF3 group and the TSA control group after 60 days of root drenching treatment. The aboveground part (plant height) of the JF3 group was significantly increased by 31.4% compared to the TSA control group (p<0.05), and the whole plant fresh weight was significantly increased by 13.04% compared to the TSA control group (p<0.05). These results demonstrate that the JF3 strain can effectively improve the growth of the aboveground part and the whole plant fresh weight of American ginseng seedlings.

[0121] Table 7. Growth status of American ginseng seedlings in the JF3 group and the TSA control group 60 days after root irrigation treatment (n=3)

[0122] growth indicators JF3 TSA Group Above-ground parts / Plant height (cm) 18.83±0.35 14.33±0.40 Stem circumference (cm) 1.43±0.15 1.23±0.05 Underground part / root length (cm) 17.7±0.52 18.26±0.58 Whole plant fresh weight (g) 8.32±0.06 7.36±0.22

[0123] Test Example 4

[0124] Evaluation of the growth-promoting effect of Corydalis yanhusuo strains in pot experiments on seedlings

[0125] 1. Root irrigation with bacterial solution

[0126] The identified JF3 bacteria (Pseudomonas atagonensis) were inoculated into TSA liquid medium and cultured at 25°C with shaking at 200 rpm for 1 day. The resulting bacterial suspension was then adjusted to OD200. 600 = Approximately 0.8, used for subsequent root irrigation with bacterial solution, while the control treatment was TSA liquid culture medium treated in the same way.

[0127] 2. Sample selection and processing

[0128] About 30 Corydalis seeds of suitable size and full grains were selected and subjected to low-temperature germination treatment. After germination, Corydalis seeds were planted in pots (all Corydalis seeds were disinfected with 75% ethanol before planting, and all soil was sterilized at 121℃ for 15 minutes. One Corydalis seedling was planted in each pot and the same weight of sterilized soil was added). After all the seeds had germinated, they were divided into groups, and 15 Corydalis seedlings of uniform growth and health were selected from each group and labeled as JF3 bacteria and TSA control.

[0129] 3. Verification of the effect of promoting fertility

[0130] On the 8th day after the seedlings of Corydalis yanhusuo in pots sprouted, the seedlings were treated with 30 mL / plant of root-drenching bacterial solution. A control group received the same treatment with an equal volume of sterile TSA liquid culture medium. The seedlings treated with root drenching were placed in a sterile light incubator for natural growth. During the growth period, they were watered with sterile water every 3 days, with day and night temperatures of 22℃ and 18℃, a light duration of 14 hours, and a darkness duration of 10 hours. After 30 days of root drenching treatment, the length of the above-ground and underground parts, the fresh weight and dry weight of the whole plant, the transverse and longitudinal diameters of the tubers, their fresh weight and dry weight, and the total alkaloid content of the tubers in each treatment group were measured (growth status after treatment is shown in the figure). Figure 10(As shown in (A)(B)). (Above-ground part: The height from the top of each Corydalis plant to the surface of the soil in the pot was measured using a ruler; Below-ground part: After the above-ground part of the Corydalis plant was measured, the above-ground part was cut off with scissors, and the length of the below-ground part was measured using a ruler; Dry weight determination: After washing the soil, the plant was freeze-dried, and the dry weight was measured afterward; Total alkaloid content (3 replicates): The total alkaloid content determination kit was purchased from Baisha Biotechnology Co., Ltd., catalog number BL1762B).

[0131] 4. Results Analysis

[0132] Figure 11 The image shows a comparison of whole-plant growth of Corydalis seedlings in the JF3 strain treatment group and the TSA control group after 30 days of root drenching treatment. The image shows that the overall growth of Corydalis seedlings treated with JF3 strain root drenching was better than that treated with TSA medium alone. Furthermore, the aboveground parts of the seedlings treated with the bacterial solution were longer than those in the TSA medium treatment group. Figure 12 Tables 8 and 9 show the comparison of the aboveground and underground part lengths, whole plant fresh weight, dry weight, tuber transverse diameter, longitudinal diameter, fresh weight, and dry weight of Corydalis seedlings in the experimental group and the TSA control group after 30 days of root drenching treatment. The tables show that after root drenching with JF3 bacterial solution, the overall Corydalis seedlings treated with this method showed better results than those treated with only TSA medium. The aboveground part length of the Corydalis seedlings increased by 31.13% compared to the TSA treatment group (p<0.05). Figure 13 Table 10 shows the comparison of the total alkaloid content in Corydalis tubers of the JF3-treated group and the TSA control group after 30 days of root irrigation treatment. The results show that the total alkaloid content in Corydalis tubers treated with JF3 bacteria was significantly increased (p<0.05), increasing by 185.60% compared to the TSA-treated group. These results indicate that the JF3 strain can effectively promote the growth of Corydalis seedlings and the accumulation of total alkaloids in Corydalis tubers.

[0133] Table 8. Phenotypic comparison of Corydalis seedlings in the JF3-treated group and the TSA control group 30 days after root irrigation treatment (n=15)

[0134]

[0135] Table 9. Phenotypic comparison of Corydalis tubers in the JF3-treated group and the TSA control group 30 days after root irrigation treatment (n=15)

[0136] serial number transverse diameter (cm) Longitudinal diameter (cm) Fresh weight (g) Dry weight (g) JF3 1.33±0.43 1.20±0.31 1.11±0.76 0.27±0.21 TSA control group 1.30±0.17 1.28±0.29 0.91±0.26 0.22±0.07

[0137] Table 10 Comparison of total alkaloid content after JF3 treatment (n=3)

[0138] strain number Total alkaloid content (ug / g) JF3 386.01±13.40 TSA comparison 135.16±5.38

[0139] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A strain of Pseudomonas atagonensis JF3, characterized in that, The accession number is: CGMCC No.34848.

2. A microbial agent, characterized in that, Includes the Pseudomonas bacteria JF3 as described in claim 1.

3. The microbial agent according to claim 2, characterized in that, The bacterial agent comprises a bacterial suspension; the OD of the bacterial suspension is... 600 =0.

8.

4. The use of the Pseudomonas bacterium JF3 as described in claim 1 or the inoculum as described in claim 2 or 3 in promoting plant growth and / or improving plant quality.

5. The application according to claim 4, characterized in that, The promotion of plant growth includes promoting the growth of plant seedlings and / or promoting the growth of plant tubers; the plant includes at least one of Corydalis yanhusuo, Arabidopsis thaliana and Panax quinquefolius.

6. The application according to claim 5, characterized in that, The promotion of plant seedling growth includes at least one of 1) to 3): 1) Promotes the growth of the above-ground parts of plant seedlings; 2) Promotes the length of the underground part of plant seedlings; 3) Increase the fresh weight and / or dry weight of the whole plant seedling; The promotion of plant tuber growth includes at least one of (1) to (3): (1) Increase the transverse diameter of plant tubers; (2) Increase the longitudinal diameter of plant tubers; (3) Increase the fresh weight and / or dry weight of plant tubers.

7. The application according to claim 4, characterized in that, The improvement of plant quality includes increasing the total alkaloid content in Corydalis tubers.

8. The application according to claim 4, characterized in that, The plant growth promotion is achieved through nitrogen fixation, dissolution of inorganic phosphorus, and / or secretion of siderophores by Pseudomonas bacteria JF3.

9. A method for promoting plant growth and / or improving plant quality, characterized in that, Includes the following steps: Apply the Pseudomonas spp. bacterium JF3 as described in claim 1 or the inoculum agent as described in claim 2 or 3 to plant seedlings.

10. The method according to claim 9, characterized in that, The application method includes root irrigation.

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