Application of sunflower HaIAA1 gene in improving abiotic stress tolerance of plants

Abstract

The invention relates to the technical field of abiotic stress tolerance of plants, and discloses application of a sunflower HaIAA1 gene in improvement of abiotic stress tolerance of plants. According to the invention, the sunflower HaIAA1 gene is connected to a plant overexpression vector, and the sunflower is transformed by using an agrobacterium infection method, so that the result shows that the physiological status of the sunflower infected and transformed by the HaIAA1 gene under salt stress and drought stress is obviously superior to that of a wild type sunflower, which indicates that the sunflower HaIAA1 gene can obviously improve the salt tolerance of a transgenic plant. The invention provides a theoretical basis and a gene source for modifying or cultivating other new varieties of crops such as salt-tolerant sunflowers and the like, and is beneficial to fundamentally improving the salt tolerance of the crops.

Description

Technical Field

[0001] The present invention relates to the technical field of plant abiotic stress resistance, and in particular to application of a sunflower HaIAA1 gene in improving plant abiotic stress resistance. Background Art

[0002] In an environment where salinity and drought coexist, salt stress and water shortage significantly interfere with seed water absorption and the early development of the radicle by reducing osmotic potential, inducing ion toxicity, and limiting water supply. High salt and drought conditions inhibit starch decomposition and enzyme activity within seeds, delaying germination time and reducing germination rate, thereby affecting the construction and function of the seedling root system and even weakening subsequent photosynthesis and respiration processes. This not only threatens the early survival of crops, but also has a significant impact on the final yield and quality. Therefore, improving the salt and drought tolerance of plants through genetic engineering has important scientific value and application prospects.

[0003] Sunflower (Helianthus annuus L.) is an important oilseed and economic crop in the world. It is widely cultivated because it is rich in unsaturated fatty acids, protein, vitamins and other nutrients. However, with the continuous expansion of the cultivated area, sunflower is facing increasingly severe biotic and abiotic stresses, which seriously threaten its yield. Salt stress and drought, as two common osmotic stresses, are the main abiotic factors limiting crop growth and yield. Plants respond to these stresses by regulating cellular osmotic pressure and ion homeostasis. Therefore, the discovery and application of key stress-tolerant genes in sunflower under salt and drought stress will help expand arable land and improve resource utilization. However, at present, research on the key genes and their regulatory mechanisms in sunflower's response to abiotic stresses such as salt and alkali tolerance and drought tolerance is still relatively limited.

[0004] Virus-induced gene silencing (VIGS) is a rapid, genetically engineered reverse genetics tool that requires no genetic transformation and is widely used for the efficient verification of gene function in plants. This technique uses viral vectors to introduce target gene fragments into plants, activating endogenous RNA silencing mechanisms and achieving efficient suppression of specific genes. Applying VIGS to the functional analysis of sunflower stress-resistance-related genes will not only accelerate the discovery of molecular mechanisms of stress tolerance but also provide a theoretical basis and technical support for the cultivation of superior varieties with salinity and drought adaptability. Summary of the Invention

[0005] In order to solve the above-mentioned technical problem of improving the salt and drought tolerance of plants, the present invention provides an application of a sunflower HaIAA1 gene in improving the abiotic stress tolerance of plants.

[0006] The specific technical solutions of the present invention are: In a first aspect, the present invention provides an application of a sunflower HaIAA1 gene in improving plant resistance to abiotic stress, wherein the amino acid sequence of the protein encoded by the sunflower HaIAA1 gene is shown in SEQ ID NO.2.

[0007] Preferably, the nucleotide sequence of the sunflower HaIAA1 gene is shown as SEQ ID NO.1.

[0008] The sunflower HaIAA1 gene is derived from sunflower (Helianthus annuus L.), and specifically belongs to a member gene of the sunflower Aux / IAA gene family.

[0009] This study linked the sunflower HaIAA1 gene to a plant overexpression vector and transformed the sunflower using Agrobacterium infection. The results showed that the physiological state of the transformed sunflowers under salt and drought stress was significantly better than that of wild-type sunflowers, demonstrating that the sunflower HaIAA1 gene can significantly improve the salt tolerance of transgenic plants. This study provides a theoretical basis and gene source for the modification or cultivation of new salt-tolerant sunflower varieties, including those of other crops.

[0010] Preferably, the application method is: increasing the expression level of the sunflower HaIAA1 gene in plants.

[0011] In a second aspect, the present invention provides an application of a sunflower HaIAA1 gene in improving the resistance of a plant to abiotic stress. The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.1.

[0012] Preferably, the application method is: improving the resistance of plants to abiotic stress by increasing the expression of the sunflower HaIAA1 gene in plants.

[0013] In a third aspect, the present invention provides an application of a sunflower HaIAA1 gene in cultivating plant varieties with abiotic stress, wherein the nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.1.

[0014] Preferably, the expression of the sunflower HaIAA1 gene is increased in plants to breed plant varieties that are resistant to abiotic stress.

[0015] In a fourth aspect, the present invention provides a method for cultivating abiotic stress-resistant transgenic plants, comprising the following steps: The sunflower HaIAA1 gene shown in SEQ ID NO. 1 was transferred into plants to obtain transgenic plants resistant to abiotic stress environments.

[0016] Compared with the prior art, the present invention has the following technical effects: This study linked the sunflower HaIAA1 gene to a plant overexpression vector and transformed the sunflower using Agrobacterium infection. The results showed that the transformed sunflowers exhibited significantly better physiological conditions under salt and drought stress than wild-type sunflowers, demonstrating that the HaIAA1 gene significantly improves the salt tolerance of transgenic plants. This study provides a theoretical basis and gene source for the development or cultivation of new salt-tolerant crop varieties, such as sunflowers, and helps fundamentally improve the salt tolerance of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the gene silencing vector pTRV2.

[0018] Figure 2 Identification of TRV2-HaIAA1 Agrobacterium single colony positive clones.

[0019] Figure 3 These are the phenotypes and statistical diagrams of the sunflower plants in the control group and the silent group when no abiotic stress treatment was performed in Example 2, wherein (A) is the phenotype diagram and (B) is the statistical diagram of the differences.

[0020] Figure 4 This is a gelatin image of sunflower seedling VIGS identification.

[0021] Figure 5 represents the HaIAA1 gene expression levels in the control group and the silenced group before abiotic stress treatment.

[0022] Figure 6 These are the phenotype diagrams of sunflower under salt stress and PEG stress, where Figure A is 200mM NaCl treatment, and Figure B is 20% PEG treatment. In the figure, EV represents the control group, which is the wild-type sunflower, and TRV-HaIAA1 represents the silenced group, which is the sunflower with virus-induced HaIAA1 gene silencing.

[0023] Figure 7 The content and distribution of ROS in the leaves of the control group and the silence group after abiotic stress treatment.

[0024] Figure 8 Schematic diagram of gene overexpression vector 1305-GFP vector.

[0025] Figure 9 These are the phenotype diagrams of sunflower under salt stress and PEG stress, where Figure A is 200mM NaCl treatment, and Figure B is 20% PEG treatment. In the figure, EV represents the control group, which is the wild-type sunflower, and HaIAA1-GFP represents the overexpression group, which is the sunflower with overexpression of the HaIAA1 gene. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the following embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a portion of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0027] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used are conventional biochemical reagents and drugs unless otherwise specified. The experiments were repeated three times or more, and the results were averaged.

[0028] In environments where salinity and drought coexist, salt stress and water shortages significantly interfere with seed water uptake and early radicle development by reducing osmotic potential, inducing ion toxicity, and limiting water supply. This not only threatens early crop survival but also significantly impacts final yield and quality. Therefore, improving plant salt and drought tolerance through genetic engineering is of great significance.

[0029] In order to solve the above technical problems, on the one hand, the present invention provides an application of a sunflower HaIAA1 gene in improving plant resistance to abiotic stress, and the amino acid sequence of the protein encoded by the sunflower HaIAA1 gene is shown in SEQ ID NO.2.

[0030] The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.1.

[0031] The sunflower HaIAA1 gene is derived from sunflower (Helianthus annuus L.), and specifically belongs to a member gene of the sunflower Aux / IAA gene family.

[0032] In one embodiment, experiments conducted to increase the expression of the HaIAA1 gene as shown in SEQ ID NO. 1 in sunflower revealed that increasing the expression of the HaIAA1 gene in sunflower significantly improved the plant's tolerance to salt and drought environments and significantly reduced the accumulation of reactive oxygen species in its leaves, without affecting the plant's normal growth. The above embodiment demonstrates that overexpression of the protein encoded by the HaIAA1 gene as shown in SEQ ID NO. 2 can significantly alter the sunflower's ability to withstand saline-alkali and drought stresses. Therefore, the HaIAA1 gene as shown in SEQ ID NO. 1 and its encoded protein can be used to improve plant tolerance to abiotic stresses.

[0033] In one embodiment, the application method is: increasing the expression level of the sunflower HaIAA1 gene in a plant.

[0034] In a second aspect, the present invention provides an application of a sunflower HaIAA1 gene in improving the resistance of a plant to abiotic stress. The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.1.

[0035] Stress resistance refers to the ability of an organism to survive and grow in an unfavorable environment (adversity), also known as adversity resistance. Adversity includes drought, flooding, high temperature, low temperature, salinity, pests and diseases, etc. In one embodiment, by conducting an experiment to increase the expression level of the HaIAA1 gene shown in SEQ ID NO.1 in sunflower, it was found that after increasing the expression level of the HaIAA1 gene in sunflower, the sunflower can significantly improve the plant's tolerance in a salt environment and significantly reduce the accumulation of active oxygen in its leaves without affecting the normal growth of the plant. The above examples show that expressing the HaIAA1 gene in plants can improve the ability of plants such as sunflower to resist saline-alkali adversity and drought resistance, so that they can adapt to adversity through their own physiological, biochemical and morphological adjustments, maintain life activities, and even maintain good growth and reproductive capacity.

[0036] In one embodiment, the application method is: improving the plant's resistance to abiotic stress by increasing the expression of the sunflower HaIAA1 gene in the plant.

[0037] In a third aspect, the present invention provides an application of a sunflower HaIAA1 gene in cultivating plant varieties with abiotic stress, wherein the nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.1.

[0038] In one embodiment, the application method is: increasing the expression of the sunflower HaIAA1 gene in plants to breed plant varieties that are resistant to abiotic stress.

[0039] In a fourth aspect, the present invention provides a method for cultivating abiotic stress-resistant transgenic plants, comprising the following steps: The sunflower HaIAA1 gene shown in SEQ ID NO. 1 was transferred into plants to obtain transgenic plants resistant to abiotic stress environments.

[0040] The application of the HaIAA1 gene can provide a new genetic resource for cultivating new plant varieties with high stress resistance, and further implement the aforementioned method for cultivating transgenic plants resistant to abiotic stress environments, namely, transferring the sunflower HaIAA1 gene as shown in SEQ ID NO. 1 into plants to obtain transgenic plants resistant to abiotic stress environments. This method for cultivating transgenic plants resistant to abiotic stress environments has important application value in the cultivation of plant germplasm resistant to abiotic stress and agricultural production.

[0041] In the embodiments of the present invention, the primer sequence information involved is shown in Table 1.

[0042] Table 1 Example 1 Construction of transgenic sunflower expressing HaIAA1 gene 1. Construction of HaIAA1 gene silencing expression vector (TRV2-HaIAA1) and HaIAA1 gene overexpression vector (HaIAA1-GFP) 1. Obtaining the Target Gene: PCR amplification was performed using sunflower cDNA as a template using primers TRV2-HaIAA1-F, TRV2-HaIAA1-F, HaIAA1-GFP-F, and HaIAA1-GFP-R. Gel recovery and purification were performed to obtain the HaIAA1 gene fragment and cDNA fragment. The PCR reaction system is shown in Table 2. The nucleotide sequence of the HaIAA1 gene fragment is shown in SEQ ID NO. 1, and the amino acid sequence of the encoded protein is shown in SEQ ID NO. 2.

[0043] Table 2 PCR reaction system (50 μL) Reaction components volume 2xBuffer 25 μL dNTP lμL Forword Primer (10μM) 2μL Reverse Primer (10μM) 2μL Phanta Max Super-Fidelity DNA Polymerase 1 μL cDNA 1 μL <![CDATA[ddH2O]]> Up to 50μL The PCR reaction program was set as follows: pre-denaturation at 95°C for 3 min; denaturation at 95°C for 15 s, annealing at 56°C for 15 s, and extension at 72°C for 30 s, for 35 cycles; and complete extension at 72°C for 5 min.

[0044] 2. Digest the TRV2 vector with BamHI and EcoRI, recover and purify the fragments on a gel for subsequent recombination reactions. Digest the 1305-GFP vector with BamHI and xbalI, recover and purify the fragments on a gel for subsequent recombination reactions. Use the recombination method to construct the TRV-HaIAA1 and HaIAA1-GFP expression vectors. After preparing the recombination system, place it in a metal bath at 50°C for 15 minutes to obtain the HaIAA1 gene silencing expression vector recombinant plasmid pTRV2-HaIAA1 and the overexpression vector recombinant plasmid HaIAA1-GFP. The enzyme digestion system is shown in Tables 3 and 4, and the recombination system is shown in Table 5.

[0045] Schematic diagram of pTRV2 vector is shown in Figure 1 . The pTRV2 vector can be obtained through existing technology. It is a vector commonly used in plant virus-induced gene silencing (VIGS) technology. pTRV2 is part of the tobacco rattle virus (TRV) binary vector system, which includes two vectors, pTRV1 and pTRV2; the pTRV2 vector carries part of the target gene. When it is introduced into plant cells together with pTRV1, it will trigger the RNA silencing mechanism in the plant, resulting in the inhibition of the expression of the target gene, so that the function of the target gene can be studied by observing the phenotypic changes of the plant. In this step, the amplified part of the target gene is cloned into the pTRV2 vector to construct the gene silencing vector pTRV2-HaIAA1.

[0046] A schematic diagram of the 1305-GFP vector is shown in Figure 8 The 1305-GFP vector is a pCAMBIA series plant binary expression vector that can be obtained using existing technologies. It has a high-efficiency promoter and is suitable for Agrobacterium-mediated overexpression of the HaIAA1 gene.

[0047] Table 3 TRV2 enzyme digestion system (40 μL) Reagents volume TRV2 vector 10 μL EcoRI 2μL BamHI 2μL CutSmart(10X) 4μL <![CDATA[ddH2O]]> 22 μL Table 41305-GFP enzyme digestion system (40 μL) Reagents volume 1305-GFP vector 10 μL xbalI 2μL BamHI 2μL CutSmart(10X) 4μL <![CDATA[ddH2O]]> 22 μL Table 5 Recombination system (5 μL) Reagents 0.5μL CEII ExnaseII (10x) 1 μL carrier 1 μL Destination fragment 1 μL 5xBuffer 1 μL <![CDATA[ddH20]]> 1 μL 3. Plasmid transformation The above recombinant product was transferred into 50 μL of E. coli competent cells, flicked to mix, and then placed on ice for 30 minutes, heat-shocked at 42°C for 45 seconds, and placed on ice for 2 minutes; 500 μL of LB medium was added, 37°C, 200 rpm, incubated for 1 hour, and then spread on the solid medium of LB+Kana, and inverted in a 37°C constant temperature incubator for overnight culture. 100 μL of the liquid culture medium in the revived centrifuge tube was evenly spread on the LB solid medium containing Kan (kanamycin) resistance, and the plate was inverted and placed in a 37°C incubator for overnight culture (12 hours); positive clones with pTRV2-HaIAA1 were screened, and strains with kanamycin resistance were positive clones. The colony PCR results of the positive clones with pTRV2-HaIAA1 are as follows: Figure 2 .

[0048] 2. Genetic Transformation of Sunflower The successfully constructed TRV2-HaIAA1 recombinant plasmid was transformed into GV3101 Agrobacterium, and the positive clones were picked and inoculated into 3 mL of LB liquid medium containing Rif (rifampicin) and Kan (kanamycin) antibiotics. The culture was incubated at 28°C, 200 rpm, and overnight. The next day, the culture was expanded into 100 mL of LB medium (containing Kan and rif antibiotics) until the bacterial liquid OD reached 0. 600 =0.6-0.8, then centrifuge at 4000 rpm for 20 min to harvest the bacteria. Resuspend the bacteria in infection buffer (Table 6) and adjust the solution OD 600 The concentration of the sunflower seeds was 0.6 to 1, and the mixture was kept at room temperature in the dark for 2 hours. The sunflower seeds that had been shelled and soaked in sterile water for 2 days were randomly divided into 2 groups. One group was soaked in a mixed culture of Agrobacterium transformed into TRV1 and Agrobacterium transformed into TRV2. As the control group, HaIAA1 gene silencing was not performed and it was named EV group. The Agrobacterium transformed into TRV1 and Agrobacterium transformed into TRV2 were mixed in a volume ratio of 1:1, and the concentration of the culture was OD 600 =0.7; another group was immersed in a mixed bacterial solution of Agrobacterium transformed with TRV1 and Agrobacterium transformed with TRV2-HaIAA1, as the HaIAA1 gene silencing group, named TRV-HaIAA1 group, wherein the Agrobacterium transformed with TRV1 and the Agrobacterium transformed with TRV2-HaIAA were mixed in a volume ratio of 1:1, and the bacterial solution concentration was OD 600 =0.7.

[0049] The two groups of sunflower seeds were incubated in the dark at 28°C for 1 hour and then vacuumed three times. They were then germinated in the dark in a culture room for three days with the embryo tip facing downward. After the cotyledons and roots grew, they were hydroponically cultured in 1 / 5 Hoagland medium for 12 days. After 12 days of culture, the phenotypes of the sunflower plants in the EV group and the TRV-HaIAA1 group were as follows: Figure 3 shown. Figure 3 A is a comparison of the phenotypes of sunflower before and after silencing. The stems of the silenced group are shorter than those of the control group. Figure 3 B shows that, through statistics, except for stem length, there were no significant differences in root length, leaf length and fresh weight ( Figure 3 B).

[0050] Table 6 Infection Buffer (400mL) Example 2 This example identifies sunflower plants with HaIAA1 gene silenced and tests and verifies their performance. The specific steps are: (1) Total RNA was extracted from the sunflower plant material samples of the TRV-HaIAA1 group in Example 1 using the FastPure Universal Plant Total RNA Isolation Kit (Vazyme, Nanjing, China). Subsequently, cDNA was synthesized using HiScriptIIQ Select RT SuperMix (Vazyme, Nanjing, China).

[0051] (2) PCR amplification was performed using specific primers for TRV1 and TRV2 to identify the silent strains. The sunflower silent identification gel image is shown in the figure below. Figure 4 The results showed that TRV1 and TRV2 plasmids had been successfully transferred into the control group and silenced group, respectively.

[0052] (3) Before treatment, qRT-PCR analysis was performed using the CFX384 Touch Real-Time PCR Detection System (Bio-Rad, Hercules, California, USA), and each experiment was repeated three times. The qRT-PCR Master Mix used was ChamQ Universal SYBR qPCR Master Mix (Vazyme, Nanjing, China). The relative expression level was calculated using the 2^(-ΔΔCt) method, with HaTublin as the internal reference gene. The expression levels of the HaIAA1 gene in the two groups of sunflower strains in Example 1 were also detected, and the results are shown in Table 1. Figure 5 The results showed that the expression level of HaIAA1 gene in the silencing group was significantly lower than that in the control group.

[0053] Example 3 Experiment on salt and drought tolerance of sunflower with virus-induced silencing of HaIAA1 The sunflower plants of the EV group and the TRV-HaIAA1 group obtained in Example 1 were cultured in the hydroponic culture medium Hoagland for 12 days. Under salt stress treatment, the seedlings of the EV group were cultured in an environment of 1 / 5 Hoagland solution or 1 / 5 Hoagland solution plus 200mM NaCl for 6 hours, and the seedlings of the TRV-HaIAA1 group were cultured in an environment of 1 / 5 Hoagland solution or 1 / 5 Hoagland solution plus 200mM NaCl for 6 hours; under drought stress treatment, the seedlings of the EV group were cultured in a 1 / 5 Hoagland solution or a 1 / 5 Hoagland solution containing 1 / 5 Hoagland solution plus 20% PEG (polyethylene glycol) for 6 hours, and the seedlings of the TRV-HaIAA1 group were also cultured in a 1 / 5 Hoagland solution or a 1 / 5 Hoagland solution containing 1 / 5 Hoagland solution plus 20% PEG (polyethylene glycol) for 6 hours.

[0054] After the polyethylene glycol and salt treatment, the control group and the silent group were taken for phenotypic observation. Under salt stress, the leaves of the silent group wilted more and lost water faster. Figure 6 As shown in A. Under PEG treatment, the silent group lost water faster and the leaves wilted more, as shown in Figure 6 As shown in B. The results showed that the tolerance of the silenced group to salt stress and drought stress was reduced compared with the control group.

[0055] After treatment with polyethylene glycol and salt, the leaves of sunflower strains in the silenced and control groups were stained with DAB and NBT to detect the content and distribution of ROS. After treatment with salt and PEG, the reactive oxygen species content in the silenced and control groups was significantly different, and the ROS staining color of the silenced group strains was darker, as shown in Figure 2. Figure 7 The results showed that the silenced group produced more reactive oxygen species in sunflower leaves after salt stress and drought stress than the control group.

[0056] The experiment showed that under normal circumstances, there was not much difference in the growth status of the control group sunflower and the sunflower after virus-induced silencing. However, under salt stress and drought stress, the salt tolerance and drought tolerance of the sunflower after virus-induced silencing of HaIAA1 were lower than those of the wild-type sunflower.

[0057] Example 4 Salt and drought tolerance experiment of sunflower overexpressing HaIAA1 gene The recombinant plasmid HaIAA1-GFP obtained in Example 1 was transferred into Escherichia coli, and positive cloned Escherichia coli carrying HaIAA1-GFP was screened out. The HaIAA1 gene was overexpressed in sunflower plants by Agrobacterium-mediated transfection, specifically as follows: (1) the recombinant plasmid HaIAA1-GFP obtained in Example 1 was transferred into 50 μL of Escherichia coli competent cells, flicked to mix, and then placed on ice for 30 min, heat-shocked at 42°C for 45 s, and placed on ice for 2 min; 500 μL of LB medium was added, incubated at 37°C, 200 rpm, and then spread on LB+Kana solid culture medium, and incubated inverted in a 37°C constant temperature incubator overnight. 100 μL of the liquid culture medium in the revived centrifuge tube was evenly spread onto LB solid culture medium containing Kan (kanamycin) resistance, and the plate was placed upside down in a 37°C incubator for overnight (12 hours); positive clones carrying pTRV2-HaIAA1 were screened, and strains with kanamycin resistance were the positive clones.

[0058] (2) The successfully constructed HaIAA1-GFP recombinant plasmid was transformed into GV3101 Agrobacterium, and the positive clones were picked and inoculated into 3 mL of LB liquid medium containing Rif (rifampicin) and Kan (kanamycin) antibiotics. The culture was carried out at 28 ° C and 200 rpm for 12 hours overnight. The next day, the culture was transferred to 100 mL of LB medium (containing Kan and rif antibiotics) and expanded to a bacterial liquid OD of 0. 600 =0.6-0.8, then centrifuge at 4000 rpm for 20 min to collect the bacteria.

[0059] (3) Resuspend the cells in infection buffer (see Table 6) and adjust the OD value of the solution. 600 The sunflower seeds that had been shelled and soaked in sterile water for 2 days were randomly divided into 2 groups. One group was soaked in the Agrobacterium solution transformed with 1305-GFP. The OD value of the solution was 0.6-1. 600 =0.7, as the control group, named EV group; the other group was immersed in the bacterial solution of Agrobacterium GV3101 transformed with the recombinant plasmid HaIAA1-GFP, and the bacterial solution OD 600 =0.7, and the overexpression group was named HaIAA1-GFP group.

[0060] The two groups of sunflower seeds were incubated in the dark at 28°C for 1 hour and then vacuumed three times. They were then germinated in a dark room for three days, with the embryo tip facing downward. After the cotyledons and roots had grown, they were hydroponically cultured in a 1 / 5 Hoagland medium for 12 days to obtain seedlings from the EV and HaIAA1-GFP groups, respectively.

[0061] (4) In the salt stress treatment, the seedlings of the EV group and the HaIAA1-GFP group were cultured in a 1 / 5 Hoagland solution or a 1 / 5 Hoagland solution plus 200 mM NaCl environment for 6 hours. In the drought stress treatment, the seedlings were cultured in a 1 / 5 Hoagland solution containing 20% PEG (polyethylene glycol) for 6 hours. The phenotypic results of sunflower after salt stress and PEG stress treatment are shown in Figure 9 .

[0062] Depend on Figure 9 It was shown that after salt treatment, the leaves of sunflower plants in the control group wilted more and lost water faster than those in the overexpression group ( Figure 9 A). After PEG treatment, leaves of sunflower plants in the control group lost water faster and wilted more than those in the overexpression group ( Figure 9 B).

[0063] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. Application of the sunflower HaIAA1 gene in improving plant tolerance to abiotic stress, characterized by: The amino acid sequence of the protein encoded by the sunflower HaIAA1 gene is shown in SEQ ID NO.

2.

2. The use according to claim 1, characterized in that: The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.

1.

3. The use according to claim 1, characterized in that: The application method is: increasing the expression level of the sunflower HaIAA1 gene in plants.

4. Use of the sunflower HaIAA1 gene for improving plant resistance to abiotic stress, characterized in that: The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.

1.

5. The use according to claim 4, characterized in that: The application method is: improving the resistance of plants to abiotic stress by increasing the expression of the sunflower HaIAA1 gene in plants.

6. Use of the sunflower HaIAA1 gene in breeding plant varieties resistant to abiotic stress, characterized by: The nucleotide sequence of the sunflower HaIAA1 gene is shown in SEQ ID NO.

1.

7. The use according to claim 6, characterized in that: The application method is: increasing the expression of the sunflower HaIAA1 gene in plants to breed plant varieties that are resistant to abiotic stress.

8. A method for cultivating transgenic plants resistant to abiotic stress environments, characterized by: The following steps are involved: The sunflower HaIAA1 gene shown in SEQ ID NO. 1 was transferred into plants to obtain transgenic plants resistant to abiotic stress environments.

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