A gene associated with plant secondary wall synthesis and cold resistance and applications thereof

Abstract

The application discloses a gene related to plant secondary wall synthesis and cold resistance and application thereof, and belongs to the technical field of genetic engineering.The application successfully separates and identifies a transcription factor PgSCWCR1 related to secondary wall synthesis and cold resistance and a coding gene thereof from Phyllostachys nidularis, the lignin, cellulose and hemicellulose contents of rice overexpressing the gene are all significantly improved by 34%, 12% and 15% respectively, the rice overexpressing the gene is less damaged than wild type rice under the same low temperature stress, the leaf green is better maintained, and wilting is slowed down, and the application provides a gene related to plant secondary wall synthesis and cold resistance. PgSCWCR1 The gene can be used as a candidate gene related to plant secondary wall synthesis and cold resistance, and is used for rapidly realizing the improvement of plant (including bamboo) properties and cold resistance by using a genetic engineering method, and has important practical significance for greatly shortening a breeding cycle and a breeding workload.

Description

Technical Field

[0001] This invention relates to the field of genetic engineering technology, and in particular to a gene related to plant secondary cell wall synthesis and cold resistance, and its applications. Background Technology

[0002] light bamboo ( Phyllostachys glauca As an important plant of the genus *Phyllostachys* in the subfamily Bambusoideae of the Poaceae family, it occupies an important position in my country's forestry resources. It is characterized by rapid growth, high yield, and strong adaptability, making it an excellent substitute for timber. Furthermore, *Phyllostachys pubescens* is widely distributed from the Yellow River basin to the Yangtze River basin, with a wide range of adaptability, and is one of the most commonly cultivated bamboo species. It has significant economic, ecological, and ornamental value. In particular, its strong cold resistance makes it a representative bamboo species widely introduced and studied.

[0003] The composition of the secondary cell wall is a key factor influencing the wood properties of *Phyllostachys edulis*, and researching the synthetic regulatory mechanisms of its components is of great significance for improving these properties. Furthermore, cold adaptation leads to changes in cell wall composition and the activity of enzymes involved in cell wall modification, resulting in thickening of the secondary cell wall, which plays a crucial role in the plant's cold resistance. However, research on the regulation of secondary cell wall synthesis and cold resistance by transcription factors in *Phyllostachys edulis* is still in its early stages. Therefore, providing a key candidate gene / transcription factor related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis* is of great significance for rapidly improving the wood properties and resistance of plants (including bamboo) using modern biotechnology. Summary of the Invention

[0004] The purpose of this invention is to provide a gene related to plant secondary cell wall synthesis and cold resistance and its application, and to provide a key candidate gene / transcription factor related to plant secondary cell wall synthesis and cold resistance to accelerate variety improvement.

[0005] To achieve the above objectives, the present invention provides a gene related to plant secondary cell wall synthesis and cold resistance, wherein the gene is... PgSCWCR1 The gene and its CDS sequence are shown in SEQ ID NO.2.

[0006] Preferably, the plant includes bamboo or rice; overexpression of the gene increases the content of secondary cell wall components and also improves cold resistance.

[0007] Preferably, the secondary wall components include lignin, cellulose, and hemicellulose.

[0008] A transcription factor associated with plant secondary cell wall synthesis and cold resistance, the transcription factor being encoded by the aforementioned gene, the amino acid sequence of which is shown in SEQ ID NO.1.

[0009] The application of genes related to plant secondary cell wall synthesis and cold resistance as described above in plant variety breeding, wherein the selected plant varieties are those with better wood properties and / or cold resistance.

[0010] Biological materials containing the above-mentioned genes, wherein the biological material is a gene expression cassette, expression vector, cloning vector, or engineered bacteria.

[0011] The application of biomaterials as described above in plant variety breeding, wherein the selected plant varieties are those with better mechanical strength and / or cold resistance.

[0012] A method for improving the composition of secondary cell walls and / or cold resistance in grasses by overexpressing the aforementioned genes in grasses.

[0013] Therefore, the present invention provides a gene related to plant secondary cell wall synthesis and cold resistance, and its application, with the following specific technical effects: (1) In this invention, a transcription factor PgSCWCR1 and its encoding gene related to secondary wall synthesis and cold resistance were successfully isolated and identified from bamboo. The transgenic rice was successfully transferred into wild rice through transgenic technology. The transgenic rice had lignin, cellulose and hemicellulose contents increased by 34%, 12% and 15% respectively, and secondary wall thickness increased by 50% compared with wild rice, indicating that the transcription factor PgSCWCR1 is related to secondary wall formation. The transgenic rice suffered less damage under the same low temperature stress conditions than wild rice, the leaves were better kept green and the degree of wilting was slowed down, indicating that the transcription factor PgSCWCR1 may improve the cold resistance of rice by increasing the content of secondary wall components. (2) This invention provides a candidate gene related to plant secondary cell wall synthesis and cold resistance. By overexpressing the transcription factor PgSCWCR1 or its encoding gene in the plant, the content of secondary cell wall components (lignin, cellulose and hemicellulose) in rice can be effectively increased, thereby improving the plant's cold resistance. It can be used as a candidate gene to quickly improve the wood properties and cold resistance of plants (including bamboo) using genetic engineering methods, greatly shortening the breeding cycle and the amount of breeding work.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 In Embodiment 1 of the present invention PgSCWCR1 The agarose gel electrophoresis image shows the CDS sequence amplification products; lane 1 represents the amplification products at Tm=55℃; lane 2 represents the amplification products at Tm=56.9℃; lane 3 represents the amplification products at Tm=58.8℃; lane 4 represents the amplification products at Tm=61.1℃; lane 5 represents the amplification products at Tm=63℃; lane 6 represents the amplification products at Tm=65℃; M represents DL2000. Figure 2 In Embodiment 1 of the present invention PgSCWCR1 Electrophoresis diagram of double enzyme digestion verification of recombinant plasmid expression vector, where lanes 1-5 are the double enzyme digestion products of five recombinant plasmids, and M is DL15000; Figure 3 In the rice plant of Example 3 of the present invention PgSCWCR1 PCR test results, where lane M is DL2000; lane 1 is pCAMBIA1300-Ubi-GFP-FLAG- PgSCWCR1 Plasmid; Lane 2 represents wild-type rice plants (WT); Lanes 3-7 represent different transgenic rice lines; Figure 4 In Embodiment 3 of the present invention PgSCWCR1 The results of relative expression levels in transgenic rice plants; where WT represents wild-type rice, and OE-1 to OE-5 represent different transgenic rice lines; different lowercase letters indicate significant differences in expression levels ( p <0.05); Figure 5 In Embodiment 4 of the present invention PgSCWCR1 Expression levels of genes related to the synthesis of secondary cell wall components (lignin, cellulose, and hemicellulose) in transgenic rice; where A represents... OsCESA4 Gene; B is OsCESA7 Gene; C is OsCESA9 Gene; D is OsPAL1 Gene; E is OsPAL5 Gene; F is Os4CL3 Gene; G is Os4CL4 Gene; H is OsCAD1 Gene; I is OsCAD2 Gene; J is OsIRX9 Genes; WT represents wild-type rice, while OE-1 and OE-4 are transgenic rice lines. Different lowercase letters indicate significant differences in expression levels. p <0.05); Figure 6 In Embodiment 5 of the present invention PgSCWCR1Analysis results of the secondary cell wall composition of transgenic rice, where A represents lignin; B represents cellulose; C represents hemicellulose; WT represents wild-type rice; and OE-1 and OE-4 represent transgenic rice lines. Different lowercase letters indicate significant differences in content. p <0.05); Figure 7 These are scanning electron microscope images of the wild-type and overexpression lines in Example 6 of this invention; the scale bar is 10 μm. Figure 8 The results show the determination of secondary cell wall thickness in wild-type and overexpression lines in Example 6 of this invention; the scale bar is 10 μm; ** indicates extremely significant differences (…). p <0.01), ns indicates that the difference is not significant; Figure 9 Images of plants after low-temperature treatment in Example 6 of this invention; scale bar is 10cm; Figure 10 These are the results of relative conductivity and malondialdehyde (MDA) content determination in wild-type and transgenic rice in Example 6 of this invention; where A represents relative conductivity; B represents MDA; different lowercase letters indicate significant differences ( p <0.05). Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Unless otherwise defined, the technical or scientific terms used in this invention have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0019] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. Experimental instruments, equipment, and reagents in the following embodiments that do not specify their sources are all commercially available materials.

[0020] Unless otherwise defined or stated, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein can be applied to the methods of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0021] This invention provides a transcription factor PgSCWCR1 related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis*, the amino acid sequence of which is shown in SEQ ID NO.1. It should be noted that the *Phyllostachys edulis* transcription factor PgSCWCR1 increases the content of secondary cell wall components (lignin, cellulose, and hemicellulose) in rice, thereby improving the plant's cold resistance. It has broad application prospects in plant-oriented breeding and provides a new genetic resource for genetic engineering of plant material properties and adaptability improvement.

[0022] Furthermore, PgSCWCR1, a transcription factor related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis*, belongs to the ERF transcription factor family, one of the most important families of transcriptional regulatory proteins in plants. Current research has identified numerous ERF family genes in many plants, and the study of these family members is quite in-depth. These transcription factors contain a conserved AP2-DNA domain of approximately 60 amino acids, which can recognize and bind specific cis-acting elements, thereby regulating the transcriptional activity of target genes.

[0023] This invention also provides a gene related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis*, which encodes the transcription factor PgSCWCR1, a transcription factor related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis*. It should be noted that the nucleic acid encoding PgSCWCR1 can be any nucleotide sequence that encodes the amino acid sequence shown in SEQ ID NO. 1. As described above, expression or overexpression of this nucleotide sequence in the plant can increase the content of secondary cell wall components (including lignin, cellulose, and hemicellulose) in rice, thereby improving the plant's cold resistance.

[0024] In some specific embodiments, the nucleotide sequences of the genes related to secondary cell wall synthesis and cold resistance in *Phyllostachys edulis* are shown in SEQ ID NO. 2. It should be noted that the nucleotide sequence shown in SEQ ID NO. 2 can encode the amino acid sequence shown in SEQ ID NO. 1. Furthermore, it should be understood that the nucleotide sequence in this invention can also be a sequence obtained by codon optimization of the sequence shown in SEQ ID NO. 2. As described above, expression or overexpression of this nucleotide sequence in the plant can increase the content of secondary cell wall components (lignin, cellulose, and hemicellulose) in rice, thereby improving the plant's cold resistance.

[0025] This invention also provides a biological material comprising the above-described nucleotide sequence. It should be noted that this biological material can be any biological vector that can be used to express the above-described nucleotide sequence, including but not limited to gene expression cassettes, expression vectors, cloning vectors, or engineered bacteria. Gene expression cassettes, expression vectors, and cloning vectors are well known in the art. Furthermore, Agrobacterium is generally selected as the engineered bacteria to mediate the transfection of exogenous target genes into plants.

[0026] This invention also provides a method for increasing the content and thickness of secondary wall components (lignin, cellulose, and hemicellulose) in rice: introducing the nucleotide sequence shown in SEQ ID NO.2 into the plant, thereby increasing the content of secondary wall components (lignin, cellulose, and hemicellulose). It should be noted that introducing the nucleotide sequence into the plant is a technique known in the art. In some specific embodiments, the above-mentioned nucleotide sequence can first be constructed into an expression vector, and then transgenic plants containing the above-mentioned nucleotide sequence can be obtained through Agrobacterium-mediated transformation, thereby increasing the content of secondary wall components (lignin, cellulose, and hemicellulose).

[0027] This invention also provides a method for improving plant cold resistance: introducing the nucleotide sequence shown in SEQ ID NO.2 into the plant to improve its cold resistance. It should be noted that introducing the nucleotide sequence into the plant is a technique known in the art. In some specific embodiments, the method can first construct an expression vector from the above nucleotide sequence, and then obtain transgenic plants containing the above nucleotide sequence using Agrobacterium-mediated transformation, thereby improving plant cold resistance.

[0028] In some specific embodiments, rice can be selected as the plant for the methods described above for increasing the content of secondary cell wall components (lignin, cellulose, and hemicellulose) and improving plant cold resistance. Rice and bamboo are both monocotyledonous plants, and rice plays an important role in botanical research, often being used as a model organism. Therefore, this invention uses rice plants for functional verification.

[0029] It should be noted that, in this invention, by introducing the above-mentioned nucleotide sequence into wild-type rice, the transgenic rice obtained has increased lignin, cellulose, and hemicellulose content by 34%, 12%, and 15% respectively compared with wild-type rice, and alleviated the damage caused by low-temperature stress to rice. This indicates that the nucleotide sequence in this invention can achieve significant effects in increasing the content of secondary wall components (lignin, cellulose, and hemicellulose) and improving plant cold resistance.

[0030] To better understand the present invention, the following specific embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0031] Example 1 Obtain a transcription factor gene related to secondary cell wall synthesis and cold resistance in bamboo. PgSCWCR1 The coding region sequence is as follows: According to the genome of *Phyllostachys edulis* PgSCWCR1Primers were designed based on the CDS sequence, as follows: upstream primer: 5′-ATGGCCGCAGCTATAGATAT-3′ (SEQ ID NO.3), downstream primer: 5′-TCATGAGAGGATTGAGTCCC-3′ (SEQ ID NO.4). RNA was extracted from *Lophatherum gracile* leaves using a kit and reverse transcribed into cDNA as a template for amplification. PCR amplification was performed at different annealing temperatures (Tm) (55℃, 56.9℃, 58.8℃, 61.1℃, 63℃, and 65℃) to determine the optimal amplification temperature. The reaction system was prepared according to the instructions accompanying the Taq enzyme, and the amplification program was: 95℃ for 5 min; 98℃ for 15 s, Tm for 30 s, 72℃ for 1 min 14 s, for 35 cycles.

[0032] The PCR amplification products were detected by agarose gel electrophoresis, and the results are as follows: Figure 1 As shown, the target band was present at each Tm value. The target band was excised and purified using a kit. The recovered DNA fragment was ligated into the pCE3 BluntVector vector and transformed into E. coli DH5α competent cells. Single colonies were selected for sequencing to obtain positive clones. The plasmid of the positive clone was extracted and sent to the company for sequencing. The results showed that the inserted gene fragment (recovered DNA fragment) was 1035 bp, the nucleotide sequence of which is shown in SEQ ID NO.2, and the encoded amino acid sequence of which is shown in SEQ ID NO.1.

[0033] SEQ ID NO.1: MAAAIDMYKYNTSTHQIASSASDQELMKVLGPFIRSAASSSSSSPSPPYYSSPMTQDSYMHTPTSYTSLTTLPLPTTTTTATTSSSFSQLPPLYSSQYAASAASAMTGSIGLTHLGPAQIQQIQAQFLVQQRQQQQQQRGLAGAFLGPRAQTMKQSGSPPRAAAAQSKLY RGVRQRHWGKWVAEIRLPKNRTRLWLGTFDTAEDAALAYDKAAFRLRGDLARLNFPSLRRGGAHLAGPLHASVDAKLTAICQSLAAPSSKNAAATAAESAASAAEPESPKCSSSTEGEESVSAGSPPPPTSLAPPVPEMERLDFTEAPWDESETFHLCKYPSWEIDWDSILS SEQ ID NO.2: Example 2 Build and carry PgSCWCR1 The plant expression vectors for genes are as follows: Primers were designed based on the sequence shown in SEQ ID NO.2, and then introduced... Bam H Ⅰ and Pml I. Restriction site, primer sequences are as follows: Upstream primer: 5′-TGTTACTTCTGCAGggatccATGGCCGCAGCTATAGATAT-3′ (SEQ ID NO.5) (lowercase letters are...) Bam H Ⅰ site); downstream primer: 5′-CTCACCATAGGCCTcacgtgTGAGAGGATTGAGTCCC-3′ (SEQ ID NO. 6) (lowercase letters are 3′ and 4′ respectively) Pml I. Site). Using the *Phyllostachys edulis* cDNA obtained in Example 1 as a template, PCR amplification was performed using primers shown in SEQ ID NO. 5 and SEQ ID NO. 6, prepared according to the instructions accompanying the Taq enzyme. The amplification program was: 95℃ for 5 min; 98℃ for 15 s, 60℃ for 30 s, 72℃ for 1 min 14 s, for 35 cycles. The PCR amplification products were detected by agarose gel electrophoresis. The target band was excised and purified. The recovered DNA fragment was ligated into the pCAMBIA1300-Ubi-GFP-FLAG vector using a one-step cloning method under 50℃ water bath conditions for 10 min, and transformed into *E. coli* DH5α competent cells. Kanamycin (50 μg / mL) was picked. -1 Single clones grown on resistant plates were used to extract plasmids, which were then identified by restriction enzyme mapping (using...). Bam H Ⅰ and Pml I. Enzyme digestion, such as Figure 2 (as shown) and sequencing verification, to obtain the contents PgSCWCR1 The recombinant expression vector for the gene was named pCAMBIA1300-Ubi-GFP-FLAG- PgSCWCR1 .

[0034] Example 3 PgSCWCR1 The details of rice transformation and qPCR detection are as follows: Since rice and bamboo are both monocotyledonous grasses and are closely related, and most importantly, rice has a very mature genetic transformation system, the recombinant expression vector obtained in Example 2 was used to transform GV3101 Agrobacterium and then infect rice callus tissue (for specific operation steps, please refer to: Zhu Chenglei. Identification and Molecular Regulatory Mechanism of PeTIP4-3, a Key Gene of Aquaporin in Bamboo [D]. Chinese Academy of Forestry, 2024. DOI:10.27625 / d.cnki.gzlky.2024.000112.). PCR amplification was performed using primers shown in SEQ ID NO.5 and SEQ ID NO.6 to verify the results (e.g., ...). Figure 3 As shown in the figure, five transgenic rice lines were finally obtained: OE-1, OE-2, OD-3, OE-4, and OE-5.

[0035] Total RNA was extracted from each transgenic rice plant and wild-type rice (WT) plant using a kit and reverse transcribed into cDNA. The obtained cDNA was then used as a template for qPCR. OsUBQ This is an internal reference. The results are as follows: Figure 4 As shown, the target gene was detected in all transgenic rice plants. PgSCWCR1 The expression level of the target gene was significantly higher than that of wild-type rice plants (WT). The expression levels of the target gene in transgenic rice lines OE-1 and OE-4 were 38 times and 36 times higher than those in wild-type rice plants, respectively. Therefore, these two lines were selected for further research.

[0036] Example 4 Test Example 3 obtained PgSCWCR1 The expression of genes related to the synthesis of secondary cell wall components in transgenic rice is as follows: The expression patterns of genes in the biosynthetic pathways of secondary cell wall components (lignin, cellulose, and hemicellulose) in transgenic rice plants were analyzed using qPCR. Primer sequences are shown in Table 1, and the internal control was [missing information]. OsUBQ The result is as follows Figure 5 As shown, compared with wild-type rice plants, the expression of all known genes related to secondary cell wall components is significantly upregulated in transgenic plants.

[0037] Table 1 Primer sequence information used for qPCR

[0038] Example 5 PgSCWCR1 Analysis of the composition and thickness of the secondary cell wall in transgenic rice is as follows: Lignin, cellulose, and hemicellulose were extracted from WT and transgenic rice lines using kits, respectively. The contents of lignin, cellulose, and hemicellulose in WT and transgenic lines were then determined by colorimetry. The results are shown below. Figure 6 As shown, compared with wild-type rice, genetically modified rice... PgSCWCR1 The lignin, cellulose, and hemicellulose contents of rice increased by 34%, 12%, and 15%, respectively; the secondary cell wall thickness of WT and transgenic lines was measured by scanning electron microscopy, and the results showed that, as Figure 7-8 As shown, compared with wild-type rice, genetically modified rice... PgSCWCR1 The thickness of the secondary cell wall in rice increased by 50%. In summary, PgSCWCR1 Overexpression of this substance can increase the content of secondary cell wall components (lignin, cellulose, and hemicellulose) and the thickness of secondary cell walls in rice.

[0039] Example 6 PgSCWCR1 The cold resistance of genetically modified rice was determined, as detailed below: Transgenic lines OE-1 and OE-4 were transplanted into diluted 1000× Kimura B rice culture medium and grown at 25℃ under a photoperiod of 10h / 14h (light / dark). Wild-type (WT) and transgenic rice were planted simultaneously. Plant photos of WT and transgenic rice after simultaneous treatment at 4℃ for 72h are shown below. Figure 9 As shown, compared with wild-type rice, the transgenic lines suffered less damage, maintained leaf greenness better, and exhibited reduced wilting. The relative conductivity and malondialdehyde content of leaves in wild-type and transgenic rice were measured using kits, and the results are shown below. Figure 10 As shown, the relative conductivity and malondialdehyde content of the two transgenic rice lines were significantly lower than those of wild-type rice. This indicates that the cell membranes of the two transgenic rice plants suffered less damage under low-temperature stress.

[0040] Therefore, this invention successfully isolated and identified a transcription factor PgSCWCR1 and its encoding gene related to secondary cell wall synthesis and cold resistance from *Phyllostachys edulis*. Rice overexpressing this gene showed significantly higher lignin, cellulose, and hemicellulose content compared to wild-type rice, increasing by 34%, 12%, and 15%, respectively. Rice overexpressing this gene also suffered less damage under the same low-temperature stress conditions than wild-type rice, maintained leaf greenness better, and exhibited reduced wilting. PgSCWCR1 Genes can serve as candidate genes related to plant secondary cell wall synthesis and cold resistance, and can be used to rapidly improve the wood properties and cold resistance of plants (including bamboo) using genetic engineering methods. This has important practical significance for significantly shortening the breeding cycle and reducing the amount of breeding work.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A gene associated with plant secondary cell wall synthesis and cold resistance, characterized by: The gene is PgSCWCR1 The gene and its CDS sequence are shown in SEQ ID NO.

2.

2. The gene related to plant secondary cell wall synthesis and cold resistance according to claim 1, characterized in that: The plants mentioned include bamboo and rice; overexpression of the gene increases the content of secondary cell wall components and also improves cold resistance.

3. A gene related to plant secondary cell wall synthesis and cold resistance according to claim 2, characterized in that: The secondary wall is composed of lignin, cellulose, and hemicellulose.

4. A transcription factor associated with plant secondary cell wall synthesis and cold resistance, characterized by: The transcription factor is encoded by the gene according to any one of claims 1-3, and the amino acid sequence is shown in SEQ ID NO.

1.

5. The application of genes related to plant secondary cell wall synthesis and cold resistance as described in any one of claims 1-3 in plant variety breeding, characterized in that: The selected plant varieties are those with better wood properties and / or cold resistance.

6. A biological material comprising the gene according to any one of claims 1-3, characterized in that: The biological material is a gene expression cassette, expression vector, cloning vector, or engineered bacteria.

7. The application of the biomaterials as described in claim 6 in plant variety breeding, characterized in that: The selected plant varieties are those with better mechanical strength and / or cold resistance.

8. A method for improving the composition of secondary cell walls and / or cold resistance in grasses, characterized in that: Overexpression of the gene according to any one of claims 1-3 in grasses.

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