Kiwi acerf56 gene and application thereof in drought resistance and growth improvement

Abstract

The application belongs to the field of genetic engineering, and relates to a kiwi fruit AcERF56 gene and application of the kiwi fruit AcERF56 gene in drought resistance and growth improvement. A nucleotide sequence of the kiwi fruit AcERF56 gene is shown in SEQ ID NO:1; and an amino acid sequence of a protein encoded by the AcERF56 gene is shown in SEQ ID NO:2. The drought resistance function of the gene is reported for the first time in kiwi fruit. Overexpression of the gene can significantly improve photosynthetic performance of the kiwi fruit under water stress, aboveground and underground biomass, active oxygen scavenging capacity, and drought resistance of the kiwi fruit, thereby providing a research basis for cultivation of drought-resistant and high-yield plants.

Description

Technical Field

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

[0002] Kiwifruit is a high-value-added fruit crop worldwide, and China is the world's largest kiwifruit producer. Kiwifruit is highly sensitive to drought stress. Its low axial xylem resistance, high hydraulic conductivity, and high transpiration rate make it a water-sensitive and drought-intolerant fruit tree. Drought stress can severely impact normal photosynthesis and transpiration, ultimately affecting the plant's overall morphology, biomass, and quality, causing significant losses to agriculture. Drought occurs in kiwifruit-producing areas worldwide, but is particularly severe in my country's high-quality kiwifruit-producing areas in northwest China. It is one of the most significant abiotic factors hindering the sustainable development of the global kiwifruit industry. Therefore, there is an urgent need to cultivate drought-tolerant kiwifruit varieties.

[0003] 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 worldwide. 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 species scavenging, and play an important role in coping with 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 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 1071 bp; the amino acid sequence of the protein encoded by the AcERF56 gene (AcERF56 protein) is shown in SEQ ID NO: 2, and is composed of 356 amino acids. Overexpression of this gene as a target gene in kiwifruit can improve the photosynthetic efficiency, biomass, active oxygen scavenging ability, and drought resistance of kiwifruit under water stress conditions. The kiwifruit AcERF56 gene of 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] Another object of the present invention is to provide a recombinant vector.

[0010] The present invention also aims to provide a recombinant engineered 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 engineered 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-yielding kiwifruit.

[0014] The present invention also aims to provide a drought-resistant and high-yielding 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, the nucleotide sequence of which 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 kiwifruit AcERF56 gene, the protein encoded by the kiwifruit AcERF56 gene, the recombinant vector, or the recombinant engineered bacteria are used to resist drought and improve the growth of kiwifruit. Overexpression of the AcERF56 gene can improve the photosynthetic performance and growth of kiwifruit under drought stress, thereby increasing the drought resistance of kiwifruit. The AcERF56 gene, the protein encoded by the gene, the constructed recombinant vector, and the recombinant engineered bacteria can be used to resist drought and improve the growth of kiwifruit.

[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 includes overexpressing the kiwifruit AcERF56 gene or the protein encoded by the kiwifruit AcERF56 gene in the kiwifruit.

[0023] Disclosed is a drought-resistant and high-yield kiwifruit, which 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 present invention discloses the application of the 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. This is of great significance for the cultivation of 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 : The sequence alignment results of the kiwifruit AcERF56 gene and the Arabidopsis EPF family gene in Example 1 of the present invention are shown in Figure 1. a represents the phylogenetic analysis results of the Arabidopsis AP2 / ERF family genes and the kiwifruit AcERF56 gene, and b represents the amino acid sequence alignment results of the protein encoded by the kiwifruit AcERF56 gene and 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 the three transgenic lines with high overexpression levels 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 line, and c represents the abundance identification result of the AcERF56 protein in the transgenic line.

[0029] Figure 4 This figure shows the morphological growth of the transgenic kiwifruit strain under drought treatment in Example 3 of the present invention. The scale is 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 These are 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 graph shows 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, which, however, are not intended to limit the present invention in any way. 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 were commercially available.

[0035] Culture medium configuration

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

[0037] Kiwifruit pre-culture 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 culture medium temperature drops to about 60°C, add zeatin (1 mg / L) 1.5 mL in a 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 culture medium temperature drops to about 60°C, add zeatin (1 mg / L) 2 mL and acetosyringone (200 nmol / mL) 1 mL in a 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, and when the culture medium temperature drops 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, and when the culture medium temperature drops 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] Previous research by the inventors' research group revealed that the kiwifruit gene AcERF56 responds to ABA and regulates cytokinin metabolic homeostasis, potentially contributing to drought adaptation in kiwifruit, including changes in photosynthetic performance, morphological growth, and reactive oxygen species scavenging capacity. The inventors further analyzed the distant relationships between the kiwifruit gene AcERF56 and members of the Arabidopsis ERF gene family and cloned the kiwifruit gene AcERF56, which shares the closest homology 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 from the Actinidia chinensis genome (Red5_PS1_1.69.0, https: / / plants.ensembl.org / Actinidia_chinensis). Primers AcERF56-F and AcERF56-R were designed to amplify the homologous gene from the Actinidia chinensis genome, namely the Actinidia chinensis AcERF56 gene of the present invention. The sequence of primer AcERF56-F is: 5'-CGGGGGACGAGCTCGGTACCATGTGCTT TCCGAAGGTGGCGG-3' (SEQ ID NO: 3), and the sequence 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 to amplify the AcERF56 gene using primers AcERF56-F and AcERF56-R. The amplification system was as follows: 2 μL cDNA (100 ng / μL), 25 μL 2×Hieff Add PCR Master Mix (With Dye), 1 μL forward primer (AcERF56-F, 10 μmol / L), 1 μL reverse primer (AcERF56-R, 10 μmol / L), and ddH2O to 50 μL. Amplification program: initial 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 the AcERF56 gene in kiwifruit

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

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

[0052] Sequence alignment results of kiwifruit AcERF56 gene and Arabidopsis thaliana EPF family gene are shown in Figure 2. Figure 1 Figure (a) shows the phylogenetic analysis of Arabidopsis AP2 / ERF family genes and the kiwifruit AcERF56 gene, and (b) the amino acid sequence alignment of the kiwifruit AcERF56 gene and the protein encoded by the Arabidopsis AT1G43160 (RAP2.6) gene. The results show that the kiwifruit AcERF56 gene belongs to the ERF-B4 family and shares the closest homology with the Arabidopsis AT1G43160 (RAP2.6). The amino acid sequence of the protein encoded by the kiwifruit AcERF56 gene contains an AP2 domain. These results suggest that the kiwifruit AcERF56 gene may possess drought resistance similar to that of 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 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 the 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. 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 in three biological replicates using the kiwifruit actin gene (Actin) as an internal reference gene. The primer sequences used for amplification are 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 as follows: 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 program was: 95°C for 15 seconds, 60°C for 15 seconds, 72°C for 30 seconds, and 40 cycles. Finally, 2 -ΔΔCt Method for data processing.

[0060] The relative expression analysis results of AcERF56 gene in kiwifruit leaves and roots after ABA treatment and drought treatment for different treatment times are shown in Figure 2. Figure 2 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 lines

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

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

[0065] Specifically, the overexpression vector pCambia2300-GFP, which does not contain the target gene, and the resulting recombinant vector were separately transferred into GV3101 Agrobacterium and cultured until the bacterial solution had an OD value of 0.7-0.8, at which point the bacterial solution was bright orange-yellow. The recombinant vector was transferred into GV3101 Agrobacterium and cultured to obtain recombinant engineered bacteria.

[0066] (2) Construction of transgenic lines

[0067] Healthy, well-growing, 30-day-old Nongda Yuxiang kiwifruit tissue culture seedlings were selected. Three to five cuts were made on the underside of the leaves and pre-cultured in kiwifruit pre-culture medium for 1.5-2.5 days. The shaken bacterial suspension was centrifuged and the supernatant discarded. An equal volume of the resuspension solution was added and shaken to obtain a suspension. The pre-cultured leaves were soaked in the suspension for 10 minutes. The bacterial suspension was then blotted dry on filter paper and spread flat on kiwifruit co-culture medium with the underside facing up and incubated in the dark for 3 days. The leaves were then placed in kiwifruit screening medium until callus differentiated from the cuts. Once the callus on the leaf surface reached a certain size, the callus was transferred to kiwifruit budding medium to promote budding. Four weeks after budding, RNA, DNA, and protein were extracted from the leaves of the sprouting seedlings using kits. RNA, DNA, and protein levels in the sprouting seedlings were then analyzed using RT-qPCR, PCR, and Western blot, 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; 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 high overexpression levels of the AcERF56 gene from the identified positive seedlings, and numbered them as OE#1, OE#4, and OE#5. The identification results of the three transgenic lines with high overexpression levels 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; data are the mean ± SD of 3 biological replicates; 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 the 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 the 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) and positive seedlings were transferred to kiwifruit rooting medium for rooting and transplanting to obtain kiwifruit plants. Wild-type kiwifruit plants (control group, WT) and positive plants (experimental groups, OE#1, OE#4, and OE#5) were subjected to natural drought treatment. Morphological growth indicators and physiological and biochemical indices were measured on days 0 and 14 in both the experimental and control groups. Day 0, before drought, was designated as Control, and day 14, after drought, was designated 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 collected from each group to calculate the aboveground fresh weight, belowground fresh weight, and total plant fresh weight, as well as the aboveground dry weight, belowground dry weight, and total plant dry weight. The average values ​​were used to calculate fresh and dry weights, respectively. Plant height and the length of the longest root were measured using a tape measure and vernier caliper. Only roots ≥5 cm in length were counted. Leaf area was measured using an LI-3100 leaf area meter.

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

[0075] The photosynthesis-related indices and reactive oxygen species-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 species-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] Net photosynthetic rate (Pn), water use efficiency (WUE), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) were measured using the CIRAS-3 portable photosynthesis / fluorescence measurement system between 9:00 and 11:00 AM on sunny days. Each treatment was replicated 10 times. Chlorophyll concentration was determined using acetone extraction, with three replicates per treatment. Hydrogen peroxide content in plants was determined using diaminobenzidine staining. Superoxide anion content was determined using the nitro blue tetrazolium chloride method. Hydrogen peroxide and superoxide anion content were determined using visible spectrophotometry. Catalase content was determined using UV absorption spectrometry, superoxide dismutase content was determined using the hydroxylamine method, peroxidase content was determined using the guaiacol method, and malondialdehyde content was determined using the thiobarbituric acid method. Each treatment was replicated three times. Fully developed leaves or roots from 10 independent plants were pooled as one biological replicate.

[0077] Data were statistically analyzed using Microsoft Excel 2007 and SPSS 22, and histograms were analyzed using Origin 2021. 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 2. Figure 4 As shown, the scale 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 overexpression of the kiwifruit AcERF56 gene under drought stress could significantly increase the aboveground dry weight, aboveground fresh weight, underground dry weight, underground fresh weight, overall plant dry weight, overall plant 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 the kiwifruit AcERF56 gene can promote the overall drought resistance and biomass of the plant by affecting the photosynthetic performance, morphological growth, and reactive oxygen scavenging ability of kiwifruit.

[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 considered as equivalent replacement methods and are included in the scope of protection 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; the growth improvement refers to improving photosynthetic performance, morphological growth, and active oxygen scavenging ability.

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-yielding kiwifruit.

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

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