Application of PagSIZ1 gene in regulation and control of growth and development of poplar

Abstract

The invention discloses application of a PagSIZ1 gene in regulation and control of poplar growth and development, belongs to the technical field of gene engineering, and provides application of the PagSIZ1 gene in regulation and control of poplar growth and development, and the nucleotide sequence of the PagSIZ1 gene is shown as SEQ ID NO.1. The invention relates to a vector containing a PagSIZ1 gene. According to the application of the vector in regulating and controlling the growth and development of the poplar, the vector promotes the growth and development of the poplar through overexpression of the PagSIZ1 gene. The invention provides application of the PagSIZ1 gene in regulation and control of poplar growth and development, overexpression of the PagSIZ1 gene can improve the growth and development speed of the poplar, the poplar can better adapt to the growth environment, higher plant height and thicker stems can be achieved in a short time, the wood yield is remarkably increased, and the wood quality is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of genetic engineering, and in particular relates to application of PagSIZ1 gene in regulating the growth and development of poplar. Background Art

[0002] As a fast-growing broad-leaved tree species, poplar is widely distributed in temperate and cold zones of the Northern Hemisphere. Due to its fast growth rate, strong adaptability, and wide range of wood uses, it has important economic value in the fields of forestry, papermaking, and bioenergy. In addition, poplar also plays an active role in ecological restoration, soil and water conservation, and other aspects. With the increasing emphasis on sustainable development, improving the growth efficiency and quality of poplar has become a research hotspot.

[0003] Genes are the basic units that control the genetic characteristics of organisms. By regulating the expression of specific genes, effective intervention in the growth and development process of plants can be achieved. In recent years, with the development of molecular biology technology, scientists have identified and isolated many key genes involved in the growth regulation of poplars. These genes are involved in photosynthesis, cell division, hormone signal transduction and many other aspects. However, how to transform these basic research results into actual productivity remains a huge challenge. On the one hand, it is necessary to overcome the technical difficulties in the process of introducing exogenous genes; on the other hand, it is also necessary to ensure the safety and stability of transgenic plants and avoid possible environmental risks.

[0004] At present, the survival rate and growth rate of poplars in harsh environments can be significantly improved by introducing genes related to drought resistance, salt tolerance and other stress responses. Using gene editing tools such as CRISPR / Cas9 to knock out or overexpress certain key regulatory factors can effectively promote the activity of the xylem cambium and accelerate the process of stem thickening, thereby shortening the period of maturity. Modification of the rate-limiting steps in the synthesis pathway of secondary biomass such as phenylpropanoid compounds such as tannic acid will not only help improve wood quality, but also provide the possibility of developing new medicinal resources.

[0005] In summary, gene regulation, as one of the important means to improve the growth performance of poplars, has brought unprecedented opportunities as well as certain challenges. This invention aims to propose a new strategy based on gene editing technology based on existing research, in order to further explore the growth potential of poplars while ensuring safety, and to help the development of the forestry industry and the protection of the ecological environment. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes the application of the PagSIZ1 gene in regulating the growth and development of poplar. Overexpression of the PagSIZ1 gene can increase the growth and development rate of poplar, enable the poplar to better adapt to the growth environment, achieve higher plant height and thicker stems in a shorter period of time, significantly increase wood yield, and optimize wood quality.

[0007] To achieve the above object, the present invention provides the use of the PagSIZ1 gene in regulating the growth and development of poplars. The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.1.

[0008] Preferably, the growth and development of poplar is promoted by overexpressing the PagSIZ1 gene.

[0009] The present invention also provides a vector comprising the PagSIZ1 gene.

[0010] The present invention also provides application of the vector in regulating the growth and development of poplars. The vector promotes the growth and development of poplars by overexpressing the PagSIZ1 gene.

[0011] The present invention also provides an application of the PagSIZ1 gene in regulating the height of poplar trees, and the growth rate of the height of poplar trees is increased by overexpressing the PagSIZ1 gene.

[0012] The present invention also provides an application of the PagSIZ1 gene in regulating the stem thickness of poplars, and the thickening speed of the stem thickness of poplars is increased by overexpressing the PagSIZ1 gene.

[0013] The present invention also provides the application of the PagSIZ1 gene in regulating the xylem differentiation of poplars. By overexpressing the PagSIZ1 gene, the widening of the xylem area of ​​the poplars is promoted, thereby promoting the xylem differentiation of the poplars.

[0014] The present invention also provides the use of the PagSIZ1 gene in regulating the activity of poplar cambium, and by overexpressing the PagSIZ1 gene, the number of cell layers of poplar cambium is promoted to increase, thereby improving the activity of poplar cambium.

[0015] The present invention also provides the application of the PagSIZ1 gene in regulating the cellulose content of poplars, and the cellulose content in poplars is increased by overexpressing the PagSIZ1 gene.

[0016] The present invention also provides the application of the PagSIZ1 gene in regulating the lignin content of poplars, and the lignin content in poplars is increased by overexpressing the PagSIZ1 gene.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects: The present invention finds that overexpression of the PagSIZ1 gene can promote the growth and development of poplars and help poplars better adapt to various environments. Overexpression of the PagSIZ1 gene can make poplars reach higher plant heights and thicker stems in a shorter period of time, which means that more wood resources can be obtained in the same period of time, significantly increasing wood production; fast-growing poplars not only increase the amount of wood per plant, but also help to increase the total wood output per hectare of land because they can form a larger crown width at an early stage. In addition, fast-growing poplars can form a larger crown in a short period of time, play a good role in soil and water conservation, and their well-developed root system helps to fix the soil and prevent soil and water loss, which is of great significance to the ecological restoration of degraded land.

[0018] The present invention promotes the widening of the xylem region, increases the number of cambium cell layers, affects the thickness and arrangement of the xylem cell walls, and thus optimizes the physical properties of the wood, such as strength and density, etc. It can reduce defects such as cracks and knots in the wood and improve the overall quality of the wood. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 The positive identification results of the 3HA tag primer fragment, wherein A is the identification result part 1, B is the identification result part 2, and C is the identification result part 3. The numbers 1 to 21 in the figure represent 21 positive seedlings; Figure 2 The results of fluorescence quantitative PCR analysis are shown in Figure WT represents wild-type plants, and OE represents transgenic plants; Figure 3 The figure is a comparison of the phenotypes of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 in the figure represent transgenic plants; Figure 4 This is a statistical analysis of the plant height of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 in the figure represent transgenic plants. ” represents significant difference; Figure 5This is a statistical analysis of stem diameter of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 represent transgenic plants. ” represents significant difference; Figure 6 The stained sections of wild-type plants and transgenic plants at the same growth period, where A is the xylem width of wild-type plants, B is the xylem width of transgenic plants SIZ1-OE-8, C is the xylem width of transgenic plants SIZ1-OE-10, D is the number of cambium cell layers of wild-type plants, E is the number of cambium cell layers of transgenic plants SIZ1-OE-8, and F is the number of cambium cell layers of transgenic plants SIZ1-OE-10; Figure 7 This is a statistical analysis of the xylem width of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 represent transgenic plants. ” represents significant difference; Figure 8 This is a statistical analysis of the number of cambium cell layers in wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 represent transgenic plants. ” represents significant difference; Fig. 9 This is a statistical analysis of the cellulose content of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 represent transgenic plants. ” represents significant difference; Fig.10 This is a statistical analysis of the lignin content of wild-type plants and transgenic plants at the same growth period. WT in the figure represents wild-type plants, and SIZ1-OE-8 and SIZ1-OE-10 represent transgenic plants. ” indicates a significant difference. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0022] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0023] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0024] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0025] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0026] Example 1 1. Construct a poplar genetic transformation system.

[0027] 1. Construction of expression vector.

[0028] (1) Take the stems of 3-month-old '84k' poplar to clone and isolate the gene; (2) RNA was extracted from poplar stem segments using an RNA extraction kit (Shandong Sikoje Biotechnology Co., Ltd.); (3) Reverse transcription of the extracted RNA from poplar stem segments into cDNA using a reverse transcription kit (Cuisheng Biotechnology (Shanghai) Co., Ltd.); (4) The PagSIZ1 gene (SEQ ID NO. 1) was amplified using the reagent 2xTaq Master Mix (Nanjing Novozyme Biotechnology Co., Ltd.) and the PCR method. The DNA sequence of the PagSIZ1 gene was found on the phytozome (https: / / phytozome-next.jgi.doe.gov / ) website, Potri.009G015000; (5) The pCAMBIA1300 vector was cut with BamHI restriction endonuclease (New England Biotechnology (Beijing) Co., Ltd.); (6) The PagSIZ1 amplified fragment was reconnected to the BamHⅠ restriction site of the pCAMBIA1300 vector by homologous recombination using the ClonExpress®Ⅱ one-step cloning kit (Nanjing Novogene Biotechnology Co., Ltd.); (7) Transform Agrobacterium by ice bath, heat shock and other experimental methods ( Agrobacterium rhizogenes ) EHA105 (Beijing Qingke Biotechnology Co., Ltd.). After the bacterial solution was correctly identified and sequenced, the Agrobacterium was mixed with 50% glycerol and stored at -80°C for subsequent poplar infection.

[0029]

[0030] The specific primers for the PagSIZ1 gene fragment were: forward primer: 5′-TAACATGTCGACACGTGGATCCATGGATTTAGTAGCTAGTTGCAAGG-3′ (SEQ ID NO. 2); Reverse primer: 5′-AGCCTGCGGCCGCGCCGGATCCCTCAGAGTCTGAGTCGTCAATAGA-3′ (SEQ ID NO. 3).

[0031] 2. Genetic transformation of poplar leaves.

[0032] (1) Take out 1 mL of the stored bacterial solution from the -80°C refrigerator and incubate it in a liquid LB medium containing "kanamycin and rifampicin" resistance at 28°C and 220 rpm for 24 h to activate the strain. Then take a certain amount of the bacterial solution and add it to 50 mL of liquid LB medium containing the corresponding resistance and culture it until the OD 600 0.6~0.8; (2) The cells were collected by centrifugation at 5000 rpm for 10 min and cultured in a co-culture liquid medium containing 100 μM / L acetosyringone (AS) at 28°C and 220 rpm in an incubator until the OD 600 is 0.3~0.4, as the infection solution; (3) Take the 2nd to 5th tender leaves from the top of the sterile seedlings, cut several times on the main vein with a sterile blade, and soak them in the invasive dye solution for 7 minutes. Place the leaves on sterile filter paper to absorb the water, spread them flat on the co-culture solid culture medium, and keep them in the dark for 2 days; (4) Transfer the leaves to the selective medium and culture them in the dark; (5) When the callus grows to the size of a rice grain, cut it with a sterile blade and transfer it to a screening medium for bud induction for culture. (6) When the callus grows buds, cut the buds and insert them into a rooting medium for culture.

[0033] Rooting medium (volume 1L): 1 / 2MS 2.37g, sucrose 20g, MES 0.5g, agar 8g.

[0034] 2. Identification of positive plants.

[0035] (1) Take genetically transformed seedlings grown in rooting medium for one month and extract DNA from poplar leaves using the CTAB method; (2) The poplar leaves were positively identified using the 3HA tag primer fragment, and the results were as follows: Figure 1 Middle A, Figure 1 Medium B and Figure 1 As shown in middle C, 21 positive seedlings were obtained.

[0036] 3HA tag primer sequences: forward primer: 5'-AACGAATCTCAAGCAATCAAG-3' (SEQ ID NO.4); reverse primer: 5'-AGACAAGTTGGTAATGGTAGC-3' (SEQ ID NO.5).

[0037] 3. Gene transcription identification.

[0038] (1) RNA was extracted from the leaves of wild-type and positive seedlings using an RNA extraction kit (Shandong Sikoje Biotechnology Co., Ltd.).

[0039] (2) Reverse transcribe it into cDNA using a reverse transcription kit (Cui Sheng Biotechnology (Shanghai) Co., Ltd.).

[0040] (3) Fluorescence quantitative PCR analysis was performed, with each gene repeated three times and the PagUBQ gene used as an internal reference. The results are shown below: Figure 2 shown.

[0041] (4) Through fluorescence quantitative PCR analysis, the two strains with the highest expression levels, OE-8 and OE-10, were selected.

[0042] The specific primers for PagUBQ fluorescence quantitative PCR analysis are: forward primer: 5'-AGACCTACACCAAGCCCAAGAAGAT-3' (SEQ ID NO.6); reverse primer: 5'-CCAGCACCGCACTCAGCATTAG-3' (SEQ ID NO.7).

[0043] The specific primers for PagSIZ1 fluorescence quantitative PCR analysis are: forward primer: 5'-CAGAGTCGATGATTAAGTGTGAGG-3' (SEQ ID NO.8); reverse primer: 5'-AGTCGACAAGTCTCACAATAGAACAC-3' (SEQ ID NO.9).

[0044] 4. Identification of poplar phenotype.

[0045] Wild-type '84k' poplar and PagSIZ1-OE transgenic positive seedlings were transferred from the rooting medium to a greenhouse (photoperiod of 16 h / 8 h, light intensity of 80 μmol / m 2 / s, temperature 24-26℃, humidity 70%) for 90 days, and the plant height and ground diameter of the poplars in the greenhouse were measured every two weeks.

[0046] The results are as follows Figure 3 , Figure 4 and Figure 5 As shown, Figure 4As shown in the figure, it was found that the plant height of transgenic lines OE-8 and OE-10 increased by 10.9% and 30.3% respectively compared with the wild type; Figure 5 As shown, the stem diameters of transgenic lines OE-8 and OE-10 increased by 4.5% and 13.6%, respectively, compared with the wild type.

[0047] 5. Identification of cambium and xylem development.

[0048] 1. Paraffin section observation.

[0049] (1) The 15th internode of poplar stem (excluding the terminal bud, the first leaf is counted in order from the root) was cut into sections as experimental materials. The sections were fixed with 4% paraformaldehyde, dehydrated with ethanol of different concentrations, transparentized with mixed solutions of xylene and ethanol of different concentrations, immersed in wax, and embedded in wax to obtain paraffin blocks containing experimental materials.

[0050] (2) The paraffin blocks were sliced ​​and spread (slice thickness was 8 μm) using a microtome and a slide spreader, fixed on a glass slide, and placed in a 37°C oven to dry overnight.

[0051] (3) After the material slices are treated with xylene and different concentrations of ethanol, the dewaxed experimental materials can be obtained and stained.

[0052] (4) After staining the slice material with 0.03% toluidine blue (TBO) for 5 minutes, rinse with water and observe and photograph it with a ZEISS microscope.

[0053] The results are as follows Figure 6 As shown in Figure 2, the xylem width of the 15th internode of the PagSIZ1-OE transgenic plants (SIZ1-OE-8 and SIZ1-OE-10) was significantly increased. Figure 7 As shown, the xylem width increased by more than 15%.

[0054] 2. Oscillate the slices for observation.

[0055] (1) Take the 15th internode of the poplar stem (excluding the terminal bud, and count the first leaf in order from the root) and cut it into sections as experimental materials. Fix it on the oscillating sectioning table and perform oscillating sectioning.

[0056] (2) Carefully remove the slices (slice thickness 30 μm) using tweezers and proceed to staining.

[0057] (3) After staining the slice material with 0.03% toluidine blue (TBO) for 10 minutes, rinse with water and observe and photograph it with a ZEISS microscope.

[0058] The results are as follows Figure 6As shown in Figure 2, the number of cambium cell layers in the 15th internode of PagSIZ1-OE transgenic plants (SIZ1-OE-8 and SIZ1-OE-10) increased significantly. Figure 8 As shown, the number of cambium cell layers increases by about 2 to 3 layers.

[0059] In summary, the PagSIZ1 gene enhances the cambium activity of poplar and promotes the differentiation of xylem.

[0060] 6. Identification of cell wall components.

[0061] PagSIZ1 - Changes in cell wall composition between stems of OE spider and wild-type plants.

[0062] 1.AIR extraction.

[0063] (1) Wild-type '84k' poplar and PagSIZ1-OE transgenic positive seedlings grown in the greenhouse for 90 days were selected, and the base stems were taken as experimental materials.

[0064] (2) The collected materials were quickly frozen in liquid nitrogen, ground into powder using a tissue crusher, and placed in a centrifuge tube for AIR extraction.

[0065] (3) Place 10 mL of powder sample in a 50 mL centrifuge tube, add 80% ethanol to 10 mL, and centrifuge at 12,000 rpm for 10 min. After centrifugation, gently aspirate the upper layer of liquid with a pipette to avoid aspirating the precipitate.

[0066] (4) Add 10 mL of 80% ethanol and 10 mL of anhydrous ethanol to the above precipitate twice, and repeat the above operation.

[0067] (5) Add 10 mL of a 1:1 mixture of chloroform and methanol to the above precipitate, heat in a 37°C water bath for 40 min, centrifuge at 12,000 rpm for 10 min, gently rinse, and repeat once.

[0068] (6) Place in a fume hood and dry the precipitate.

[0069] (7) After drying in a ventilated place, a pure AIR sample can be obtained.

[0070] 2. Determination of cellulose content.

[0071] The cellulose content of PagSIZ1-OE and wild-type plants was determined using a cellulose (CLL) content kit (Suzhou Keming Biotechnology Co., Ltd.) as follows: (1) Weigh 10 mg of the above AIR sample into an EP tube, add 1 mL of reagent 1, mix thoroughly, and incubate in a 90°C water bath for 30 min; (2) After cooling, centrifuge at 8000g at 25°C for 10 min and discard the supernatant; (3) The precipitate was washed three times with distilled water (add 1 mL of distilled water to mix, vortex for 2 min, centrifuge at 8000 g, 25 °C for 10 min, and discard the supernatant); (4) Add 1 mL of acetone to the precipitate, mix well, and centrifuge at 8000 g for 10 min at 25 °C. Discard the supernatant and dry the precipitate for later use. (5) Add 0.5 mL of distilled water to the dried precipitate, place in an ice-water bath, slowly add 0.75 mL of concentrated sulfuric acid, mix well, place in an ice-water bath for 30 min, centrifuge at 8000 g, 4 °C for 10 min, remove the supernatant, dilute 20 times with distilled water and wait for determination; (6) Preparation of working solution: Add 4 mL of reagent 3 to reagent 2 and dissolve thoroughly; (7) Add 300 μL of distilled water, 70 μL of working solution and 630 μL of concentrated sulfuric acid to the blank tube, and 300 μL of sample, 70 μL of working solution and 630 μL of concentrated sulfuric acid to the assay tube, mix well, place in a 95°C water bath for 10 min, cool to room temperature, and read the absorbance of the blank tube and assay tube at 620 nm, ΔA = A assay tube - A blank tube; (8) Calculated by sample mass: Cellulose (mg / g dry weight) = [(ΔA + 0.0043) ÷ 7.875 × V1] ÷ (W × V1 ÷ V2) × 20 = 3.17 × (ΔA + 0.0043) ÷ W, where V1 is the volume of sample added, 0.3 mL; V2 is the volume of extract added, 1.25 mL; W is the dry weight of the sample, 0.01 g; and the sample dilution factor is 20.

[0072] The results are as follows Fig. 9 As shown, statistics showed that the cellulose content of transgenic lines OE-8 and OE-10 was significantly increased compared with the wild type WT.

[0073] 3. Determination of lignin content.

[0074] The lignin content of PagSIZ1-OE and wild-type plants was measured using a lignin content detection kit (BIXBIO). The steps are as follows: (1) Weigh 3 mg of the above AIR sample into a 10 mL quartz tube (one more tube for control); (2) Slowly add 250 μL of reagent 1 and 10 μL of perchloric acid along the tube wall; (3) After sealing, mix thoroughly and place in a water bath at 80°C for 40 min for acetylation. Mix slowly every 10 min and cool naturally to room temperature after the reaction is completed. (4) Add 250 μL of Reagent 2 to the cooled reaction sample, mix thoroughly, let stand at room temperature for a while, and then take 10 μL of the supernatant; (5) Transfer the supernatant and 490 μL of glacial acetic acid to a 2 ml centrifuge tube and mix well; (6) Pipette 200 μL of the reaction solution into a micro-quartz ELISA plate and measure the absorbance at 280 nm; (7) Calculation formula: Lignin content (mg / g) = × (Vsupernatant+Vglacial acetic acid) × Vacetylation / ε × d 2 ×Vsupernatant×W=1.092W× ; Lignin content (%) = lignin content × 100% / 1000 = 0.1092 × ,in, Determination tube-A blank tube; Vsupernatant: the volume of supernatant, 0.01mL; Vglacial acetic acid: the volume of glacial acetic acid added to the reaction system, 0.49mL; Vacetylation: the volume of acetylation reaction, 0.51mL; ε: lignin extinction coefficient, 23.35mL / mg / cm; d 2 : 96-well UV plate light path, 1 cm; W: sample mass, g.

[0075] The results are as follows Fig.10 As shown, statistics showed that the lignin content of transgenic lines OE-8 and OE-10 was significantly increased compared with the wild type WT.

[0076] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. Application of PagSIZ1 gene in regulating the growth and development of poplar, characterized in that: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1.

2. The application according to claim 1, characterized in that: Overexpression of the PagSIZ1 gene promotes the growth and development of poplar.

3. The application of PagSIZ1 gene in regulating the growth of poplar trees is characterized by: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. By overexpressing the PagSIZ1 gene, the growth rate of poplar plant height is increased.

4. Application of PagSIZ1 gene in regulating poplar stem diameter, characterized in that: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. By overexpressing the PagSIZ1 gene, the speed of increasing the stem diameter of poplar trees is increased.

5. Application of PagSIZ1 gene in regulating the differentiation of poplar wood xylome, characterized in that: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. Overexpression of the PagSIZ1 gene promotes the widening of the xylem region of poplars, thereby promoting the differentiation of the xylem of poplars.

6. The application of PagSIZ1 gene in regulating the activity of poplar cambium is characterized in that: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. By overexpressing the PagSIZ1 gene, the number of cell layers in the poplar cambium is promoted to increase, thereby improving the activity of the poplar cambium.

7. Application of PagSIZ1 gene in regulating cellulose content in poplar, characterized in that: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. By overexpressing the PagSIZ1 gene, the cellulose content in poplar is increased.

8. The application of PagSIZ1 gene in regulating the content of lignin in poplar is characterized by: The nucleotide sequence of the PagSIZ1 gene is shown in SEQ ID NO.

1. By overexpressing the PagSIZ1 gene, the content of lignin in poplar is increased.

Images