AcERF56 gene of kiwi fruit and application of AcERF56 gene in drought resistance and growth improvement

Abstract

The invention belongs to the field of gene engineering, and relates to a kiwi fruit AcERF56 gene and application thereof in drought resistance and growth improvement. The nucleotide sequence of the AcERF56 gene of the kiwi fruit disclosed by the invention is as shown in SEQ ID NO: 1; the amino acid sequence of the protein coded by the AcERF56 gene is as shown in SEQ ID NO: 2. The drought resistance function of the gene is reported in the kiwi fruit for the first time, the photosynthetic performance, overground and underground biomass and active oxygen scavenging capacity of the kiwi fruit under the water stress condition can be remarkably improved by overexpressing the gene, the drought resistance of the kiwi fruit is improved, and a research basis is provided for cultivation of drought-resistant and high-yield plants.

Description

Technical Field

[0001] The invention belongs to the field of genetic engineering, and in particular relates to a kiwifruit AcERF56 gene and application thereof in drought resistance and growth improvement. Background Art

[0002] Kiwifruit is a fruit crop with high added value in the world, and China is the world's largest kiwifruit producer. Kiwifruit is very sensitive to drought stress. Its axial xylem resistance is low, the plant hydraulic conductivity is high, and the transpiration rate is high. It is a drought-intolerant fruit tree that is sensitive to water. Drought stress will seriously affect the normal photosynthesis and transpiration of plants, and ultimately affect the overall morphology, biomass and quality of the plants, causing significant losses to agriculture. Drought occurs in kiwifruit producing areas around the world, and is more prominent in the high-quality kiwifruit producing areas in northwest my country. It is one of the most important abiotic factors restricting the sustainable development of the global kiwifruit industry. Therefore, it is urgent to cultivate kiwifruit varieties with strong drought resistance.

[0003] In order to optimize water use, plants have evolved a variety of adaptive mechanisms, including regulating stem and root growth, regulating photosynthesis, and altering oxidative stress responses through antioxidant activity. Improving drought resistance and growth simultaneously is an important goal of crop breeding efforts around the world. The AP2 / ERF family is an important class of plant-specific proteins that control the growth and development of plant organs, regulate plant responses to the external environment, such as photosynthesis, osmotic regulation, and reactive oxygen scavenging, and play an important role in responding to biotic and abiotic stresses. Among them, some reports have found that ERF-B4 family members RAP2.6 and RAP2.6L respond to ABA signaling and drought stress by promoting lignin deposition and root growth, respectively. Research on the kiwifruit AP2 / ERF family in drought resistance is still limited, and it is very necessary to study it. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing kiwifruit drought resistance and to provide a kiwifruit AcERF56 gene and its application in drought resistance and growth improvement.

[0005] The nucleotide sequence of the kiwifruit AcERF56 gene of the present invention is shown in SEQ ID NO:1, and the sequence length is 1071bp; the amino acid sequence of the protein (AcERF56 protein) encoded by the AcERF56 gene is shown in SEQ ID NO:2, and is composed of 356 amino acids. The gene is overexpressed in kiwifruit as a target gene, which can improve the photosynthetic efficiency, biomass, active oxygen scavenging ability and drought resistance of kiwifruit under water stress conditions. The kiwifruit AcERF56 gene in the present invention is a homologous gene of Arabidopsis thaliana RAP2.6,

[0006] There is no report on whether it has a function in drought resistance. Therefore, identifying the function of this gene in improving the photosynthetic efficiency, drought resistance and growth of kiwifruit is of great significance for production promotion and breeding of new stress-resistant kiwifruit varieties.

[0007] The purpose of the present invention is to provide a kiwifruit AcERF56 gene.

[0008] The purpose of the present invention is to provide a protein encoded by the kiwifruit AcERF56 gene.

[0009] The present invention also aims to provide a recombinant vector.

[0010] The present invention also aims to provide a recombinant engineering bacterium.

[0011] The present invention also aims to provide the application of the kiwifruit AcERF56 gene, the protein encoded by the kiwifruit AcERF56 gene, the recombinant vector or the recombinant engineered bacteria in kiwifruit drought resistance and growth improvement.

[0012] The present invention also aims to provide the use of the kiwifruit AcERF56 gene, the protein encoded by the kiwifruit AcERF56 gene, the recombinant vector or the recombinant engineering bacteria in constructing drought-resistant and high-yield kiwifruit.

[0013] The present invention also aims to provide a method for constructing drought-resistant and high-yield kiwifruit.

[0014] The present invention also aims to provide a drought-resistant and high-yield kiwi fruit.

[0015] The above-mentioned purpose of the present invention is achieved by the following technical means:

[0016] The present invention provides a kiwifruit AcERF56 gene, whose nucleotide sequence is shown in SEQ ID NO:1.

[0017] The amino acid sequence of the protein encoded by the kiwifruit AcERF56 gene is shown in SEQ ID NO:2.

[0018] A recombinant vector contains the kiwifruit AcERF56 gene.

[0019] A recombinant engineering bacterium contains the kiwifruit AcERF56 gene.

[0020] The application of the kiwifruit AcERF56 gene, the protein encoded by the kiwifruit AcERF56 gene, the recombinant vector or the recombinant engineering bacteria in kiwifruit drought resistance and growth improvement. Overexpression of the AcERF56 gene can improve the photosynthetic performance and growth of kiwifruit under drought stress, and increase the drought resistance of kiwifruit. The AcERF56 gene and the protein encoded by the AcERF56 gene, the constructed recombinant vector and the recombinant engineering bacteria can be applied to kiwifruit drought resistance and growth improvement.

[0021] The application of the kiwifruit AcERF56 gene, the protein encoded by the kiwifruit AcERF56 gene, the recombinant vector or the recombinant engineering bacteria in constructing drought-resistant and high-yield kiwifruit.

[0022] A method for constructing drought-resistant and high-yield kiwifruit, which overexpresses the kiwifruit AcERF56 gene or the protein encoded by the kiwifruit AcERF56 gene in the kiwifruit.

[0023] A drought-resistant and high-yield kiwifruit, wherein the kiwifruit contains an overexpressed kiwifruit AcERF56 gene or a protein encoded by the kiwifruit AcERF56 gene.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention discloses the application of kiwifruit AcERF56 gene in drought resistance and growth improvement. The drought resistance function of the gene is reported in kiwifruit for the first time. Overexpression of the gene can significantly improve the photosynthetic performance, aboveground and underground biomass, and active oxygen scavenging ability of kiwifruit under water stress conditions, and increase the drought resistance of kiwifruit, which is of great significance for cultivating drought-resistant and high-yield plants and provides a research basis for the cultivation of drought-resistant and high-yield plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the sequence alignment result of the kiwifruit AcERF56 gene and the Arabidopsis EPF family gene in Example 1 of the present invention, a represents the phylogenetic analysis result of the Arabidopsis AP2 / ERF family gene and the kiwifruit AcERF56 gene, and b represents the amino acid sequence alignment result of the kiwifruit AcERF56 gene and the protein encoded by the Arabidopsis AT1G43160 (RAP2.6) gene.

[0027] Figure 2 These are the relative expression analysis results of the AcERF56 gene in kiwifruit leaves and roots after ABA treatment and drought treatment for different treatment times in Example 2 of the present invention.

[0028] Figure 3These are the identification results of three transgenic strains with high overexpression of the AcERF56 gene in Example 3 of the present invention, where a represents the genomic PCR identification result, b represents the RT-qPCR identification result of the transgenic strain, and c represents the abundance identification result of the AcERF56 protein in the transgenic strain.

[0029] Figure 4 The morphological growth of the kiwifruit transgenic strains under drought treatment in Example 3 of the present invention, with a scale of 5.0 cm.

[0030] Figure 5 The figure shows the changes in morphological growth indicators of the kiwifruit transgenic strains under drought treatment in Example 3 of the present invention.

[0031] Figure 6 The changes in photosynthesis-related indicators of the kiwifruit transgenic strains under drought treatment in Example 3 of the present invention.

[0032] Figure 7 The changes in active oxygen related indicators of the kiwifruit transgenic strains under drought treatment in Example 3 of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0034] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0035] Culture medium configuration

[0036] Resuspension (1L): add 4.43g MS and 20g sucrose and sterilize at 121℃ for 21min. When the temperature of the culture medium drops to about 60℃, add 1mL of acetosyringone (200nmol / ml) in a clean bench. The solvent is distilled water.

[0037] Kiwifruit pre-culture medium (1L): add MS 4.43g, sucrose 30g, agar 7g and naphthaleneacetic acid (0.2mg / L) 200μL, the solvent is distilled water, the pH is adjusted to 5.8-5.9, wait for the culture medium temperature to drop to about 60℃, and add zeatin (1mg / L) 1.5mL in the clean bench.

[0038] Kiwifruit co-cultivation medium (1 L): add MS 4.43 g, sucrose 30 g, agar 7 g and naphthaleneacetic acid (0.2 mg / L) 200 μL, the solvent is distilled water, the pH is adjusted to 5.8-5.9, and when the temperature of the culture medium drops to about 60°C, add zeatin (1 mg / L) 2 mL and acetosyringone (200 nmol / mL) 1 mL in the clean bench.

[0039] Kiwi screening medium: add MS 4.43g, sucrose 30g, agar 7g and naphthaleneacetic acid (0.2mg / L) 200μL, the solvent is distilled water, the pH is adjusted to 5.8-5.9, wait for the culture medium temperature to drop to about 60℃, add zeatin (1mg / L) 2mL, kanamycin (50mg / L) 1mL, timentin (200mg / L) 1.5mL and carbenicillin (250mg / L) 1mL in the clean bench.

[0040] Kiwi sprout culture medium: add MS 4.43g, sucrose 30g, agar 7g and naphthaleneacetic acid (0.2mg / L) 200μL, the solvent is distilled water, the pH is adjusted to 5.8-5.9, wait for the culture medium temperature to drop to about 60℃, add zeatin (1mg / L) 3mL, kanamycin (50mg / L) 200μL, and timentin (200mg / L) 750μL in the clean bench.

[0041] Kiwifruit rooting medium (1 L): Add MS 4.43 g, sucrose 30 g, agar 7 g and indolebutyric acid (1 mg / L) 800 μL, the solvent is distilled water, and the pH is adjusted to 5.8-5.9.

[0042] Example 1

[0043] The inventor's research group found in the previous study that the kiwifruit gene AcERF56 responds to ABA and regulates the homeostasis of cytokinin metabolism, which may be involved in the drought adaptation changes in kiwifruit's photosynthetic performance, morphological growth, and reactive oxygen scavenging ability. The inventor further analyzed the distant relationship between the kiwifruit gene AcERF56 and the members of the Arabidopsis ERF gene family, and cloned the kiwifruit gene AcERF56 that is most homologous to the Arabidopsis gene AT1G43160 (RAP2.6).

[0044]

[0045] The amino acid sequence of AcERF56 protein is shown in SEQ ID NO:2, and the specific sequence is: MCFPK VADRGEPRDFVRFPATDAADDSGAPPPDAAEQATAFSGYIRSGEMTAMVSALTRVISGGTGTASLGGGTTSFGVSGSLPGVKREREEESVSTQFTEQAQRVYRGYSSNFRGAHGESSSSAAPEEFTRIVPPSITITTTAPQLPPPEVSPQEVTGERKRRYRGVRQRPWGKWAAEIRDP HKAARVWLGTFETAEAAARAYDEAALRFRGNKAKLNFPENVRSLPPLPIPASPATHFPAPAIFPTQQAQTPDIVRDYWEYSQLLQNADDFQPNRLLQQMFFASSVAGLDSHSLASDSSFSSSNSSYPLLFSGQQMGNLRPPGDQNQGDGSGGGSDFPASPWTGSGHYSPSTSS*(SEQ ID NO:2).

[0046] 1. Cloning of the kiwifruit AcERF56 gene

[0047] The CDS sequence of CEY00_Acc11606 was obtained through the Chinese kiwifruit genome (Red5_PS1_1.69.0, https: / / plants.ensembl.org / Actinid ia_chinensis), and primers AcERF56-F and AcER F56-R were designed to amplify the homologous gene of the kiwifruit genome, that is, the kiwifruit AcERF56 gene of the present invention. The sequence information of primer AcERF56-F is: 5'-CGGGGGACGAGCTCGGTACCATGTGCTT TCCGAAGGTGGCGG-3' (SEQ ID NO: 3), and the sequence information of primer AcERF56-R is: 5'-CCATGGTGTCGACTCTAGATGGTGGAGGGGGAGTAGTGG-3' (SEQ ID NO: 4).

[0048] Total RNA was extracted from Actinidia chinensis plants and reverse transcribed into cDNA using a reverse transcription kit. The cDNA was used as a template and the AcERF56 gene was amplified using primers AcERF56-F and AcERF56-R. The amplification system was: 2 μL cDNA (100 ng / μL), 25 μL 2×Hieff Plus PCR Master Mix (With Dye), 1 μL forward primer (AcERF56-F, 10 μmol / L), 1 μL reverse primer (AcERF56-R, 10 μmol / L), add ddH2O to 50 μL; amplification program: pre-denaturation at 98°C for 3 min; denaturation at 98°C for 10 sec, annealing at 60°C for 20 sec, extension at 72°C for 60 sec (35 cycles); final extension at 72°C for 5 min. The amplified product was sequenced to obtain the nucleotide sequence shown in SEQ ID NO: 1.

[0049] 2. Analysis of AcERF56 gene in kiwifruit

[0050] Phylogenetic analysis of kiwifruit AcERF56 gene was performed, and the phylogenetic tree was constructed using Mega11.0 with Arabidopsis thaliana as reference.

[0051] The protein sequences of kiwifruit AcER F56 gene and Arabidopsis thaliana EPF family genes were compared using the neighbor joining (NJ) algorithm and 1000 replicates of bootstrap analysis.

[0052] The sequence alignment results of kiwifruit AcERF56 gene and Arabidopsis thaliana EPF family gene are as follows Figure 1 As shown in the figure, a represents the phylogenetic analysis results of Arabidopsis AP2 / ERF family genes and kiwifruit AcERF56 gene, and b represents the amino acid sequence alignment results of kiwifruit AcERF56 gene and Arabidopsis AT1G43160 (RAP2.6) gene encoding protein. The results show that kiwifruit AcERF56 gene belongs to the ERF-B4 family member, kiwifruit AcERF56 gene and Arabidopsis gene AT1G43160 (RAP2.6) are the closest homology, and the amino acid sequence of the protein encoded by kiwifruit AcERF56 gene contains an AP2 domain. The above results indicate that kiwifruit AcERF56 gene may have drought resistance similar to RAP2.6.

[0053] Example 2

[0054] The expression pattern of kiwifruit AcERF56 gene was analyzed.

[0055] Thirty 20-month-old opposite-calyx kiwifruit plants were treated under drought conditions and 100 μM abscisic acid (ABA) conditions, and the corresponding root and leaf samples were collected at different time points (0, 2, 4, 6, 8, 10, 12 and 24 h) to determine the expression of kiwifruit AcERF56 gene.

[0056] Total RNA was extracted from leaves and roots of kiwifruit rootstocks before and after treatment using the OMEGA plant RNA extraction kit according to the manufacturer's instructions. The first-strand cDNA was synthesized using the FastKing gDNA Elimination RT SuperMix Kit (Tiangen, Beijing, China). Real-time quantitative PCR (RT-qPCR) was performed using a SYBR Green qPCR kit (Takara Biotechnology Inc., Dalian, China) and a Nanodrop 2000 spectrophotometer (Thermo Fisher Scientific, Madison, WI, USA). RT-qPCR was performed with kiwifruit actin gene (Actin) as the internal reference gene for 3 biological replicates. The primer sequence information used for amplification is shown in Table 1 below.

[0057] Table 1

[0058] Primers Sequence information AcERF56-qPCR-F 5'-TCAGAGGTGCCCATGGAGAG-3'(SEQ ID NO:5) AcERF56-qPCR-R 5'-GCGGTGGTTGTGATGGTGAT-3'(SEQ ID NO:6) Actin-F 5'-TGCATGAGCGATCAAGTTTCAAG-3'(SEQ ID NO:7) Actin-R 5'-TGTCCCATGTCTGGTTGATGACT-3'(SEQ ID NO:8)

[0059] The RT-qPCR reaction system was: 2 μL cDNA (100 ng / μL), 5 μL Universal SYBR Green Supermix (Bio-Rad), 0.2 μL forward primer (F, 10 μmol / L), 0.2 μL reverse primer (R, 10 μmol / L), and ddH2O was added to 10 μL; the reaction procedure was: 95°C 15 sec, 60°C 15 sec, 72°C 30 sec, 40 cycles. Finally, 2 -ΔΔCt Method for data processing.

[0060] The relative expression analysis results of AcERF56 gene in leaves and roots of kiwifruit after ABA treatment and drought treatment for different treatment time are shown in Figure 2. Figure 2 As shown, the results showed that ABA and drought treatment could significantly increase the expression of AcERF56 gene in kiwifruit roots and leaves, indicating that the expression of AcERF56 gene was significantly induced by ABA and drought.

[0061] Example 3

[0062] 1. Construction of AcERF56 gene overexpression transgenic strain

[0063] (1) Preparation of recombinant vectors and recombinant engineered bacteria

[0064] The AcERF56 gene fragment was amplified according to the method of Example 1, and the amplified gene fragment (target gene) was double-digested with XbaI and BamHI and connected to the overexpression vector pCambia2300-GFP to obtain a recombinant vector. Finally, the correctly sequenced recombinant vector was transformed into Agrobacterium competent cells GV3101, and the positive clones were detected and preserved to obtain recombinant engineering bacteria.

[0065] Specifically, the overexpression vector pCambia2300-GFP without the target gene and the obtained recombinant vector were respectively transferred into GV3101 Agrobacterium and cultured until the bacterial solution OD value was 0.7-0.8, at which time the bacterial solution was bright orange-yellow. The recombinant vector was transferred into GV3101 Agrobacterium to obtain the recombinant engineered bacteria.

[0066] (2) Construction of transgenic lines

[0067] The healthy and well-growing 30-day-old Nongda Yuxiang kiwifruit tissue culture seedlings were selected, 3-5 wounds were cut on the back of the leaves, and they were placed in the kiwifruit pre-culture medium for pre-culture for 1.5-2.5 days. The shaken bacterial solution was centrifuged and the supernatant was discarded. The same volume of resuspension was added and the suspension was shaken to obtain the suspension. The pre-cultured leaves were soaked in the suspension for 10 minutes, and then the bacterial solution on the leaves was blotted on the filter paper. Then the leaves were flattened on the kiwifruit co-culture medium with the back facing up and cultured in the dark for 3 days. The leaves were then placed in the kiwifruit screening medium until callus tissue was differentiated at the leaf incision. After the callus tissue on the leaf surface grew to a certain size, the callus tissue was transferred to the kiwifruit budding medium to promote budding. After 4 weeks of budding, the RNA, DNA and protein of the leaves of the budding seedlings were extracted using a kit, and then the RNA, DNA and protein levels of the budding seedlings were identified using RT-qPCR, PCR and Western blot techniques respectively. The kiwifruit seedlings obtained by the overexpression vector pCambia2300-GFP without the target gene are wild-type (WT) seedlings; the kiwifruit seedlings obtained by the recombinant vector are transgenic seedlings; and the transgenic seedlings with higher RNA, DNA and protein levels than the wild-type seedlings are positive seedlings.

[0068] For the next step of functional identification, the inventors screened out three transgenic positive seedling lines with higher overexpression of the AcERF56 gene from the identified positive seedlings, numbered as OE#1, OE#4, and OE#5. The identification results of the three transgenic lines with higher overexpression of the AcERF56 gene are as follows: Figure 3 As shown, a represents the genomic PCR identification results, b represents the RT-qPCR identification results of the transgenic lines, and c represents the abundance identification results of AcERF56 protein in the transgenic lines; the data are the mean ± SD of 3 biological replicates; the data were statistically analyzed by Tukey's test, *P < 0.05. Figure 3 The results showed that compared with the wild type, the expression of AcERF56 gene and AcERF56 protein in transgenic lines OE#1, OE#4, and OE#5 were significantly increased, indicating that the AcERF56 gene was overexpressed in the transgenic lines OE#1, OE#4, and OE#5, and kiwifruit transgenic lines with overexpression of the AcERF56 gene were successfully obtained.

[0069] 2. Determination of morphological growth and physiological and biochemical indicators of kiwifruit transgenic lines under drought treatment

[0070] Wild-type (WT) seedlings and positive seedlings were transferred to kiwifruit rooting medium for rooting culture and transplanting to obtain kiwifruit plants. Wild kiwifruit plants (control group, WT) and positive plants (experimental groups, OE#1, OE#4, OE#5) were subjected to natural drought treatment, and the morphological growth indexes and physiological and biochemical indexes of the samples of the experimental group and the control group were measured on the 0th and 14th days. Day 0, i.e. before drought, was recorded as Control, and day 14, i.e. after drought, was recorded as Drought.

[0071] (1) Determination of morphological growth indicators

[0072] The fresh weight, dry weight, plant height, number of leaves, length of the longest root, number of roots and leaf area of ​​kiwifruit plants were measured.

[0073] Ten plants were selected from each group to calculate the aboveground fresh weight, underground fresh weight, and overall fresh weight of the plant, and the aboveground dry weight, underground dry weight, and overall dry weight of the plant, and the average values ​​were taken to obtain the fresh weight and dry weight, respectively. The height of the plant and the length of the longest root were calculated using a tape measure and a vernier caliper, and only roots with a length of ≥5 cm were counted. Leaf area was measured using a LI-3100 leaf area meter.

[0074] (2) Determination of physiological and biochemical indicators

[0075] The photosynthesis-related indices and reactive oxygen-related indices of kiwifruit plants were measured. The photosynthesis-related indices included chlorophyll a (Chl a) content, chlorophyll b (Chl b) content, carotenoid content, total chlorophyll (Chl total) content, ratio of chlorophyll a content to chlorophyll b content (Chl a / b), net photosynthetic rate (Pn), water use efficiency (WUE), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci); the reactive oxygen-related indices included hydrogen peroxide (H2O2) content, superoxide anion (O2 - ) content, superoxide dismutase (SOD) content, peroxidase (POD) content, catalase (CAT) content, and malondialdehyde (MDA) content.

[0076] The net photosynthetic rate (Pn), water use efficiency (WUE), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) were measured by CIRAS-3 portable photosynthesis / fluorescence measurement system from 9:00 to 11:00 on sunny days. Each treatment was repeated 10 times. The chlorophyll concentration was determined by acetone extraction method, and each treatment was repeated 3 times. The diaminobenzidine method was used to detect the content of hydrogen peroxide in plants. The nitro tetrazolium chloride method was used to detect the content of superoxide anions in plants. The visible spectrophotometry method was used to determine the content of hydrogen peroxide and superoxide anions; the ultraviolet absorption method was used to determine the content of catalase; the hydroxylamine method was used to determine the content of superoxide dismutase; the guaiacol method was used to determine the content of peroxidase; and the thiobarbituric acid method was used to determine the content of malondialdehyde; each treatment was repeated 3 times. The fully developed leaves or roots of 10 independent plants were pooled together as a biological replicate.

[0077] The data were statistically analyzed using Microsoft Excel 2007 and SPSS22, and histograms were analyzed using Origin2021. The data were statistically analyzed using Tukey's test, * indicates P < 0.05, and ** indicates P < 0.01.

[0078] The morphological growth of kiwifruit transgenic lines under drought treatment is shown in Figure 4 As shown, scale bar is 5.0cm.

[0079] Changes in morphological growth indicators of kiwifruit transgenic lines under drought treatment Figure 5 shown.

[0080] Changes in photosynthesis-related indicators of kiwifruit transgenic lines under drought treatment Figure 6 shown.

[0081] Changes of active oxygen related indicators in kiwifruit transgenic lines under drought treatment Figure 7 shown.

[0082] Figure 4 , Figure 5 The results showed that under drought stress, overexpression of the kiwifruit AcERF56 gene could significantly increase the aboveground dry weight, aboveground fresh weight, underground dry weight, underground fresh weight, overall dry weight, overall fresh weight, plant height, leaf number, and longest root length of kiwifruit plants under drought stress. Figure 6 The results showed that under drought stress, overexpression of the kiwifruit AcERF56 gene could significantly increase the chlorophyll a content, carotenoid content, total chlorophyll content, the ratio of chlorophyll a content to chlorophyll b content, net photosynthetic rate, and water use efficiency of kiwifruit plants. Figure 7 The results showed that under drought stress, overexpression of the kiwifruit AcERF56 gene could significantly increase the superoxide dismutase content, peroxidase content in the leaves and peroxidase content in the roots of kiwifruit plants, and reduce the hydrogen peroxide content, superoxide anion content and malondialdehyde content in the leaves and roots.

[0083] In summary, overexpression of kiwifruit AcERF56 gene can promote the overall drought resistance and biomass of kiwifruit by affecting its photosynthetic performance, morphological growth, and reactive oxygen scavenging ability.

[0084] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A kiwifruit AcERF56 gene, characterized in that: The nucleotide sequence of the kiwifruit AcERF56 gene is shown in SEQ ID NO:

1.

2. The protein encoded by the kiwifruit AcERF56 gene according to claim 1, characterized in that: The amino acid sequence of the protein is shown in SEQ ID NO:

2.

3. A recombinant vector, characterized in that: The recombinant vector contains the kiwifruit AcERF56 gene according to claim 1.

4. A recombinant engineered bacterium, characterized in that: The recombinant engineered bacteria contains the kiwifruit AcERF56 gene according to claim 1.

5. Use of the kiwifruit AcERF56 gene according to claim 1, the protein according to claim 2, the recombinant vector according to claim 3 or the recombinant engineered bacteria according to claim 4 in drought resistance and growth improvement of kiwifruit.

6. Use of the kiwifruit AcERF56 gene according to claim 1, the protein according to claim 2, the recombinant vector according to claim 3 or the recombinant engineered bacteria according to claim 4 in constructing drought-resistant and high-yield kiwifruit.

7. A method for constructing a drought-resistant and high-yield kiwifruit, characterized in that: Overexpressing the kiwifruit AcERF56 gene of claim 1 or the protein of claim 2 in kiwifruit.

8. A drought-resistant and high-yield kiwi fruit, characterized in that: The kiwi fruit contains the overexpressed kiwi fruit AcERF56 gene according to claim 1 or the protein according to claim 2.

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