Use of PH8 protein or its coding gene in regulating plant plant height, panicle length or lodging resistance

Abstract

The present invention relates to the technical field of plant molecular breeding, and particularly relates to the application of the PH8 protein or its encoding gene in regulating the plant height, panicle length or lodging resistance of plants; the PH8 protein is cytochrome P450 CYP78A15, and the plant is a plant of the genus Oryza. The PH8 protein comprises the amino acid sequence shown in SEQ ID NO.1, and the application includes: by reducing the expression level of the PH8 protein in the plant, reducing the plant height and panicle length of the plant, and improving the lodging resistance of the plant. The present invention screens a PH8 protein related to the plant height of plants of the genus Oryza, and the plant height and panicle length of plants of the genus Oryza can be regulated by regulating the expression level of the PH8 protein in plants of the genus Oryza. The PH8 protein provided by the present invention can be used to cultivate plants of the genus Oryza with strong lodging resistance and does not affect its own yield, and has important application value.

Description

Technical Field

[0001] The present invention relates to the technical field of plant molecular breeding, and particularly to the application of the PH8 protein or its encoding gene in regulating the plant height, panicle length or lodging resistance of plants. Background Art

[0002] The key to the agricultural green revolution is the cultivation and promotion of semi-dwarf crop varieties. Subsequently, it was found that the reduction of plant height, the increase of harvest index, the enhancement of lodging resistance and nitrogen fertilizer tolerance were caused by the mutations of genes related to gibberellin (GA) metabolism and signal pathways in these varieties, which ultimately led to a significant increase in the crop yield per unit area. The semi-dwarf gene semi-dwarf 1 ( sd1 ) is a key gene for the green revolution of rice. Currently, almost all major cultivated rice varieties carry sd1 non-functional or weak-functional allelic genotypes. However, over-reliance on this single gene for rice semi-dwarf breeding often reduces the genetic diversity of cultivated rice, aggravates the homogenization trend of rice varieties, and reduces the ability of rice to resist pests and diseases. Although a large number of semi-dwarf genes have been cloned in rice, the vast majority of these genes are accompanied by serious yield losses while reducing the culm length. Therefore, further exploration of new and excellent rice semi-dwarf genes is of great significance for rice breeding improvement.

[0003] Rice plant height is regulated by multiple hormones, and there are varying degrees of interactions among these hormones, jointly forming a complex plant height regulation network. GA is one of the important hormones regulating rice plant height. The inhibition of the biosynthesis or signal transduction of active GA will lead to the reduction of rice plant height. The green revolution gene sd1 due to the functional mutation of the GA20 oxidase it encodes, resulting in a decrease in the biosynthesis of active GA, ultimately making rice semi-dwarf. Other hormones such as brassinosteroid (BR), strigolactone (SL), cytokinin (CK), and indole-3-acetic acid (IAA) also play important roles in regulating rice plant height, but very few genes related to the biosynthesis or signal transduction pathways of these hormones are widely used in rice semi-dwarf breeding. HTD1 / D17 Encoding carotenoid cleavage dioxygenase OsCCD7, which participates in the first reaction of SL biosynthesis. The partial loss of function of this gene can increase the tiller number and improve the rice yield. It has been found in research that HTD1 the haplotype of Huanghuazhan is co-selected with sd1 and is widely used in the improvement of modern rice varieties.

[0004] The prerequisite for molecular crop breeding is the discovery and cloning of superior genetic resources associated with the desired traits. In particular, superior alleles derived through map-based cloning have more direct application value. For rice, a large number of major genes associated with important agronomic traits have been discovered. However, some genes with rare allelic variants still merit discovery and utilization. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides the use of PH8 protein or its encoding gene in regulating plant height, ear length or lodging resistance of plants.

[0006] The present invention used a chromosome segment replacement line constructed by Haobuka (HBK) and Chuan 7 (C7) to identify a major QTL for plant height. PH8 , through the NIL-F2 population PH8 The gene was localized to the 26.8 kb region of chromosome 8 and confirmed by transgenic knockout and genetic complementation experiments. PH8 Control rice plant height. PH8 The C7 allele type ( PH8 C7 ) Only in a few aus It is distributed in rice and is a rare allele. It can significantly reduce plant height in both indica and japonica rice backgrounds, and has important application value in conventional rice semi-dwarf breeding. PH8 C7 Available in SD1 The weak functional allele (GR haplotype) background can reduce rice plant height without sacrificing yield; in addition, PH8 It has no dominant effect, and its heterozygous type can appropriately reduce plant height, so it can be used to improve the plant height of hybrid rice.

[0007] In a first aspect, the present invention provides the use of PH8 protein, or a gene encoding the same, or a biological material comprising the gene encoding the same, in regulating plant height, ear length, or lodging resistance of a plant;

[0008] The PH8 protein is cytochrome P450 CYP78A15, which is included in the National Rice Data Center. The present invention further provides the use of the PH8 protein or its encoding gene as an inhibition target in cultivating dwarf plants, short panicle length plants or plants with strong lodging resistance.

[0009] Those skilled in the art know that, based on the PH8 protein or its encoding gene as the inhibition target, the expression of the PH8 protein or the transcription of its encoding gene can be inhibited by various existing technical means, such as using the CRISPR-Cas9 gene editing system to perform gene knockout with its encoding gene as the target, thereby achieving the inhibition of PH8 protein expression.

[0010] The present invention further provides the use of the PH8 protein, or its coding gene, or a biological material containing its coding gene in improving the germplasm resources related to lodging resistance of Oryza plants.

[0011] Furthermore, by reducing the expression level of the PH8 protein in the plant, the plant height and panicle length of the plant are reduced, and the lodging resistance of the plant is improved; and / or by introducing the nucleotide sequence shown in SEQ ID NO.3 into the plant, the plant height of the plant is reduced, and the lodging resistance of the plant is improved.

[0012] Furthermore, the expression level of the PH8 protein in the plant is regulated (such as reduced) by any of the following methods:

[0013] Transgenic, hybridization, backcross, self-cross or asexual reproduction;

[0014] The transgenic preferably includes one or more of the following methods: Ti plasmid, plant virus vector, direct DNA transformation, microinjection, gene gun, electroporation or Agrobacterium-mediated transformation.

[0015] Furthermore, the PH8 protein includes any of the following amino acid sequences:

[0016] (1) The amino acid sequence shown in SEQ ID NO.1;

[0017] (2) An amino acid sequence of a protein with the same function obtained by substitution, insertion or deletion of one or more amino acids in the amino acid sequence shown in SEQ ID NO.1.

[0018] SEQ ID NO.1:

[0019] MDMDSSPSTQDCGGWLLYVSLAAKCGGDPCRVVGFVAVAVVAFAVTSLLHWLSPGGPAWGRYWWNRRGGLGIAAAIPGPRGLPVLGSMSLMAGLAHRKLAAAAGGSPARRRLMALSLGETRVVVTADPGVARELLASAAFADRPVKESAYGMLFHRAIGFAPYGTYWRALRRVASTHLFSPRQVSASAAQRAVIARQMVEAMRSAAAAAAGGGVAARPFLKRASLHNVMWSVFGRKYELAAPESEETAELRSMVDEGYDLLGQLNWSDHLPWLAPFDLQKTRSRCSSLVPRVNRFVTRIIDEHRARLSLAVDAAVDFTDVLLSLHGGDKLSDADMVAVLWEMIFRGTDTVAVLIEWVAARLVLHQDVQARVHDELDRVVGSDRAVTESDASKLVYLQAVIKEVLRLHPPGPLLSWARLATSDVHVGGFLIPSGTTAMVNMWAITHDPAVWPDPNEFKPERFVAGPSSDQATEFPIMGSDLRLAPFGSGRRSCPGKSLAIATVGFWVATLLHEFDWLPLSDKSRGVDLSEVLKLSCEMATPLEARLRPRRKV。

[0020] Furthermore, the coding gene of the PH8 protein includes any of the following nucleotide sequences:

[0021] (1) The nucleotide sequence shown in SEQ ID NO.2;

[0022] (2) A nucleotide sequence obtained by substitution, deletion or insertion of one or more nucleotides in the nucleotide sequence shown in SEQ ID NO.2 and capable of encoding a protein with the same function;

[0023] (3) A nucleotide sequence that can hybridize with the nucleotide sequence shown in SEQ ID NO.2 under stringent conditions.

[0024] SEQ ID NO.2:

[0025]

[0026] Furthermore, the plant is a plant of the genus Oryza, preferably rice.

[0027] Furthermore, the biological material is an expression cassette, a vector or a transgenic cell.

[0028] The transgenic cell of the present invention does not include a transgenic cell having the ability to independently develop into a complete individual, that is, it does not include a plant variety.

[0029] In a second aspect, the present invention provides a nucleic acid, which comprises: the nucleotide sequence shown in SEQ ID NO.3.

[0030] The present invention provides a PH8 rare allele PH8 C7 , in PH8 the HBK allele genotype ( PH8 HBK ), a G-to-A mutation at the splice junction of the first exon and the first intron results in PH8 alternative splicing of the mRNA, ultimately resulting in PH8 C7 the mRNA generating a new stop codon and premature termination of the translated peptide chain. Finally, the nucleotide sequence shown in SEQ ID NO.3 is obtained.

[0031] SEQ ID NO.3:

[0032]

[0033] In a third aspect, the present invention provides a method for reducing the plant height, comprising: introducing the aforementioned nucleic acid into the plant; the plant is a plant of the genus Oryza.

[0034] In a fourth aspect, the present invention provides a KASP primer combination, comprising:

[0035] Kasp-PH8-F1: 5'-TTAATTACTGGAGTACTGTACATAC-3',

[0036] Kasp-PH8-F2: 5'-TTAATTACTGGAGTACTGTACATAT-3',

[0037] Kasp-PH8-R: 5'-GACTTCACCGACGTCCTTCTCTCC-3'.

[0038] The present invention has the following beneficial effects:

[0039] The present invention has screened and obtained a PH8 protein related to the plant height of plants of the genus Oryza and its encoding gene. By gene editing the PH8 protein in plants of the genus Oryza, the plant height, panicle and other traits of plants of the genus Oryza can be effectively regulated. The PH8 protein provided by the present invention can be applied to cultivate rice varieties with strong lodging resistance and improve the germplasm resources of rice, and has important application value in the field of cultivating high-quality rice varieties. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the examples or the description of the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 is the comparison of the chromosome segment substitution line CSSL82 carrying the C7 genotype provided in Example 1 of the present invention PH8 with the parent HBK in terms of plant height, yield per plant and lodging index; wherein A shows the plant morphology of the parent HBK and C7, and B shows the plant morphology of HBK and CSSL82; the scales of A and B are both 20 cm; C is the identification of the donor fragment introduced into CSSL82, PH8 located at the end region of the long arm of chromosome 8; D is the comparison of the plant height between HBK and CSSL82; E is the comparison of the yield per plant between HBK and CSSL82; F is the comparison of the lodging index between HBK and CSSL82, and the lodging index of CSSL82 is significantly lower than that of HBK; in the figure, " " indicates significant difference, P ≤0.01, the same hereinafter.

[0042] Figure 2 is provided by Example 2 of the present invention SD1 segregating population and PH8 analysis of the genetic effect of plant height in the segregating population; wherein, A and B are respectively SD1 segregating population and PH8 histogram of the frequency distribution of plant height in the segregating population; C shows SD1 and PH8 the genetic effect of plant height at the locus, where "CC" represents the C7 homozygous genotype, "HH" represents the HBK homozygous genotype, "CH" represents the heterozygous genotype, "A" is the additive effect, "D" is the dominant effect, and |D / A| is the degree of dominance.

[0043] Figure 3 is the schematic diagram of map-based cloning of the plant height gene provided by Example 3 of the present invention PH8 ; where the black, white, and gray bars respectively represent the C7 homozygous genotype (CC), HBK homozygous genotype (HH), and heterozygous type (CH); different letters on the histogram of the progeny test indicate significant differences at the P ≤0.05 level.

[0044] Figure 4 is the schematic diagram of the functional variation sites and transcripts of the candidate genes in the parents C7 and HBK provided by Example 3 of the present invention PH8

[0045] Figure 5 is provided by Example 4 of the present invention PH8 transgenic functional mutation verification of the gene; wherein, the upper part of A shows the schematic diagram of the target position of gene editing, and the lower part shows different homozygous mutation types obtained in the ZH11 and HBK varieties using the gene editing system; B shows the PH8 plant morphology (left) and plant height comparison (right) of the homozygous mutant and transgenic negative control under the ZH11 background; C shows the PH8 plant morphology (left) and panicle length morphology (right) of the homozygous mutant and transgenic negative control under the HBK background; D is the PH8 plant height comparison (left) and panicle length comparison (right) of the homozygous mutant and transgenic negative control under the HBK background; the scales of B and C are both 10 cm.

[0046] Figure 6 is provided by Example 4 of the present invention PH8 transgenic functional complementation verification of the gene; A shows the complementary HBK allele type under the HBK-PH8 C7 backgroundPH8 Plant height phenotypes of families; B shows the comparison of plant heights between transgenic complementary positive families and negative controls; C shows HBK-PH8 C7 Complementary HBK alleles in the background PH8 Panicle length phenotypes of families; D shows the comparison of panicle lengths between transgenic complementary positive families and negative controls; The scales of A and C are both 10 cm.

[0047] Figure 7 are the haplotype analysis results provided in Example 5 of the present invention.

[0048] Figure 8 are provided in Example 6 of the present invention PH8 Application of the C7 allele genotype in reducing the plant height of indica rice 9311 and japonica rice Koshihikari; where A shows the plant height of 9311 wild type and the near-isogenic line (9311-PH8 C7 introduced with PH8 in the 9311 background C7 ); B shows the plant height of Koshihikari (KOS) wild type and the near-isogenic line (KOS-PH8 C7 introduced with PH8 in the KOS background C7 ); C and E are the comparisons of plant height and yield per plant between 9311 and 9311-PH8 C7 respectively; D and F are the comparisons of plant height and yield per plant between KOS and KOS-PH8 C7 respectively; The scales of A and B are both 20 cm.

[0049] Figure 9 are provided in Example 7 of the present invention PH8 Application of the C7 allele genotype in reducing the plant height of hybrid rice; where A shows the comparison of plant heights between hybrid rice Liangyoupeijiu (LYP9) and Peiai 64S (PA64S) and the hybrid rice (LYP9-M) crossed with 9311-PH8 C7 ; B shows the comparison of plant heights between hybrid rice Yangliangyou 6 (YLY6) and Guangzhan 63-4S (GZ63-4S) and the hybrid rice (YLY6-M) crossed with 9311-PH8 C7 ; The scales of A and B are both 20 cm. Detailed implementation manners

[0050] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts belong to the scope of protection of the present invention.

[0051] For the experimental methods involved in the following examples, unless otherwise specified, they are all conventional methods in the art. For example, reference can be made to the experimental manuals in the art or the conditions recommended in the manufacturer's instructions.

[0052] For the experimental materials and reagents involved in the following examples, unless otherwise specified, they can all be obtained commercially. For example:

[0053] Example 1: Plant height phenotypes of chromosome segment substitution line CSSL82 and its parent HBK

[0054] In this example, the parents HBK and C7 used are local variety resources independently collected by our team. Among them, HBK is a local temperate japonica rice variety in Yunnan Province, and C7 is aus rice from the Ganges River Basin. There are significant differences in plant type between HBK and C7, mainly manifested as HBK being upright and compact with few tillers, while C7 has a larger tiller angle and more tillers (see A in Figure 1 ). In this invention, a set of chromosome segment substitution line population (BC4F3 generation) was constructed with HBK as the recipient parent and C7 as the donor parent, and two major QTLs for plant height were identified. One is located on chromosome 1 and co-localizes with the Green Revolution gene sd1 , and the other QTL is located at the end of the long arm of chromosome 8 and named PH8 ; among them, there is one family CSSL82 carrying the C7 genotype PH8 (see B in Figure 1 and C in Figure 1 ). In this invention, the plant height, yield per plant, and lodging index of CSSL82 and HBK were investigated. Compared with the parent HBK, the plant height and lodging index of CSSL82 were significantly reduced (see B, D, and F in Figure 1 ), but the yield per plant did not decrease significantly (see E in Figure 1 ), indicating that PH8 the C7 genotype can reduce the plant height without reducing the yield in the HBK background and has certain breeding value.

[0055] Example 2: PH8 Genetic effect analysis of plant height of SD1 and

[0056] In this invention, by identifying the genotypes of individual plants in the chromosome segment substitution line BC4F2 generation, individual plants with heterozygous genotypes only at the PH8 and SD1 loci were obtained. Their offspring (BC4F3) were planted to obtain F2 segregation populations segregating at the PH8 and SD1 loci respectively. The plant height of individual plants in these two populations was investigated and the genetic effects of plant height of PH8 and SD1 were analyzed.

[0057] Identification using molecular markers RM431 and InDel1-32N SD1 Genotypes of individual plants in the segregating population were identified, and frequency distribution histograms were made based on the genotypes and plant height phenotypes of individual plants in the segregating population, and the genetic effects of plant height were analyzed; the results showed that, SD1 The segregating population showed a typical segregation ratio of 3:1 (tall plants: short plants) (see A in Figure 2 ), among which the plant height of individual plants with the C7 homozygous genotype was the same as that of individual plants with the heterozygous genotype and both were tall plants; SD1 The additive effect and dominant effect were 16.7 cm and 15.2 cm respectively, and the degree of dominance was 0.91, SD1 showing a dominant inheritance pattern (see C in Figure 2 ). Similarly, molecular markers RM267 and RM477 were used to identify PH8 the genotypes of individual plants in the segregating population and analyze the genetic effects of plant height; the results showed that, PH8 In the segregating population, the plant height of individual plants with the C7 homozygous genotype was significantly lower than that of individual plants with the HBK homozygous genotype; while PH8 the plant height of individual plants with the heterozygous genotype was between the two homozygous genotypes, and its plant height was close to the mid-parent value; PH8 The additive effect and dominant effect were -13.6 cm and -1.0 cm respectively, and the degree of dominance was 0.07, PH8 showing an additive inheritance pattern (see B and C in Figure 2 ). The primer sequences of the molecular markers are shown in Table 1.

[0058] Example 3: Fine mapping of plant height gene PH8 and analysis of functional variations of candidate genes

[0059] (1) Fine mapping of PH8 Seeds (BC4F4) of heterozygous individual plants at the locus described in Example 2 of the present invention were obtained, and a segregating population of 2,100 plants was planted. Through fine mapping, was mapped to the interval between molecular markers P14-M15, and this interval was about 95.1 kb (see

[0060] ). The segregating population (BC4F5) was further expanded, and by screening recombinant individual plants, identifying the genotypes of recombinant individual plants with denser molecular markers and progeny tests, finally PH8 was mapped to a 26.8 kb interval (ID38-S40) (see PH8 ); this interval only contains 1 complete annotated gene, LOC_Os08g43390, which encodes a P450 cytochrome oxidase; therefore, the present invention regards this gene as Figure 3 PH8 a candidate gene for. The primer sequences of the molecular markers are shown in Table 1. Figure 3 ; this interval only contains 1 complete annotated gene, LOC_Os08g43390, which encodes a P450 cytochrome oxidase; therefore, the present invention regards this gene as PH8 a candidate gene for. The primer sequences of the molecular markers are shown in Table 1.

[0061]

[0062] (2) PH8 Candidate gene functional variation analysis

[0063] To determine PH8 the variation of the candidate gene between the parents, the present invention compared the sequence differences of LOC_Os08g43390 between the parents by Sanger sequencing (the sequencing primer sequences are shown in Table 1). The sequencing results showed that most of the sequence differences in the promoter of this gene between the parents were the same as those between typical indica and japonica varieties (Minghui 63 and Nipponbare); however, it is worth noting that at the splicing site of the first exon and the first intron of LOC_Os08g43390 in parent C7, the base G mutated to A, resulting in alternative splicing of LOC_Os08g43390 mRNA in parent C7, generating a new stop codon in advance, and ultimately leading to truncation of the encoded protein (see Figure 4 ).

[0064] Example 4: Transgenic knockout and complementary verification of plant height gene PH8

[0065] To further verify whether LOC_Os08g43390 regulates plant height, the present invention used the CRISPR-Cas9 gene editing system to knockout this gene in the backgrounds of HBK and ZH11 (the genotype of LOC_Os08g43390 is the same as that of HBK) respectively, in order to obtain plants with functional mutations of this gene (see Figure 5 A in). The sequences of the gene editing targets are shown in Table 1. Using double targets to knockout this gene, the present invention obtained homozygous mutants with two different mutation types in the ZH11 background. Among them, the mutation type of ZH11-CR1 is that 2 bp is deleted at the first target and 1 bp is inserted at the second target; the mutation type of ZH11-CR2 is that 233 bp is deleted between the first and the second targets (see Figure 5 A in); compared with the transgenic negative control, the plant heights of ZH11-CR1 and ZH11-CR2 decreased by 10.1 cm and 8.4 cm respectively (see Figure 5 B in). In the HBK background, the present invention also obtained homozygous mutants with two different mutation types. Among them, HBK-CR1 deleted 2 bp and 3 bp at the first and the second targets respectively, and HBK-CR2 deleted 237 bp between the first and the second targets (see Figure 5 A in); compared with the negative control in the HBK background, the plant height of the mutants was significantly shorter and the panicle length was significantly shorter (see Figure 5 C in); among them, the plant heights of HBK-CR1 and HBK-CR2 decreased by 17.4 cm and 24.5 cm respectively, and the panicle lengths decreased by 2.8 cm and 1.7 cm respectively (see​Figure 5 in D) of . These results confirmed that LOC_Os08g43390 is PH8 .

[0066] Furthermore, the present invention transferred the HBK allele C7 under the background of NIL-PH8 PH8 (3 kb promoter + 1.8 kb coding region + 1 kb 3' UTR), obtained transgenic complementary positive plants, and then continuously self-crossed twice to obtain a genetically transformed stable family (see Figure 6 in A). Compared with the transgenic complementary negative family, the plant height of the positive family was significantly increased, and the panicle length was also significantly increased; among them, the plant heights of the positive families HBK-PH8 C7 -COM1 and HBK-PH8 C7 -COM2 increased by 25.7 cm and 32.5 cm respectively (see Figure 6 in B), and the panicle lengths increased by 2.4 cm and 2.7 cm respectively (see Figure 6 in C and D). Further confirmed that LOC_Os08g43390 is PH8 .

[0067] Example 5: PH8 The C7 allele genotype of is a rare allele variation

[0068] Using the 529 rice micro-core germplasm resource populations collected by this group, the present invention performed haplotype analysis on PH8 (see Figure 7 , different letters in the column of plant height effect comparison indicate significant differences at the P≤0.01 level.). According to the SNP variation information in its coding region, PH8 can be divided into 8 haplotypes (N≥3 for each haplotype); among them, HAP1 and HAP2 are mainly distributed in the temperate japonica and tropical japonica subspecies, while HAP3, HAP4 and HAP6 are mainly distributed in the indica I and indica II subgroups, HAP5 is distributed in the indica I and Aus rice subgroups, and HAP8 is mainly distributed in the Aus rice subgroup (see Figure 7 ); the alternative splicing variation of the C7 type (HAP9) is only distributed in the Aus rice subgroup, and only 4 Aus rice carry this variation; this variation accounts for only 0.8% in the entire micro-core germplasm population, indicating that PH8 the C7 allele of belongs to a rare allele genotype (see Figure 7 ).

[0069] Example 6: PH8 The C7 allele genotype of can be used to reduce the plant height of conventional indica and japonica rice

[0070] PH8 The C7 allele (PH8 C7is a rare allele that has hardly been utilized in modern cultivated rice. In the present invention, the PH8 C7 allele was introduced into the backgrounds of the excellent indica rice restorer line 9311 and the high-quality japonica rice Koshihikari (KOS), and Kasp-PH8 molecular markers were used for assisted selection to investigate the plant height and yield per plant of their near-isogenic lines (see Figure 8 ). Among them, the parental seeds of 9311 and KOS were both commercially available. The investigation results showed that, compared with the 9311 wild type, the plant height of 9311 into which the PH8 C7 allele was introduced (9311-PH8 C7 ) decreased by 20.5 cm (see A in Figure 8 and C in Figure 8 ), but the yield per plant did not decrease significantly (see E in Figure 8 ); compared with the KOS wild type, the plant height of KOS into which the PH8 C7 allele was introduced (KOS-PH8 C7 ) decreased by 10.7 cm (see B and D in C7 Figure 8 ). In terms of the yield per plant, there was no significant difference between KOS-PH8 C7 and the wild type (see F in Figure 8 ). These results indicate that the PH8 C7 allele can reduce the plant height in both indica and japonica rice, and the yield does not decrease significantly. C7 allele can reduce the plant height in both indica and japonica rice, and the yield does not decrease significantly.

[0071] Example 7: PH8 The C7 allelic genotype of

[0072] can be used to reduce the plant height of hybrid rice PH8 Since there is no dominant effect and the plant height of its heterozygous type is close to the mid-parent value, therefore PH8 the C7 allele of C7 (PH8 C7 ) can be used to reduce the plant height of hybrid rice. In the present invention, the 9311 wild type and 9311-PH8 C7 were crossed with the two-line sterile line Peiai 64S (PA64S) to obtain the hybrid rice Liangyoupeijiu (LYP9) and the improved Liangyoupeijiu (LYP9-M) respectively; the 9311 wild type and 9311-PH8 C7 were crossed with the two-line sterile line Guangzhan 63-4S (GZ63-4S) to obtain the hybrid rice Yangliangyou 6 (YLY6) and the improved Yangliangyou 6 (YLY6-M) respectively. Among them, PA64S and GZ63-4S have been widely spread in the field. Their yield-related traits were investigated, and the results showed that, compared with LYP9, the plant height of LYP9-M decreased significantly by 5.7 cm (see Figure 9In A and Table 2), the number of productive panicles per plant increased significantly, the 1000-grain weight decreased slightly, while other agronomic traits showed no obvious differences, and finally the yield per plant had no significant difference (see Table 2); compared with YLY6, the plant height of YLY6-M decreased significantly by 8.9 cm (see Figure 9 In B and Table 2), the number of productive panicles per plant increased significantly, the seed setting rate and 1000-grain weight decreased slightly, other agronomic traits showed no obvious differences, and finally the yield per plant had no significant decrease (see Table 2). These results indicate that the heterozygous type of the PH8 C7 allele can also reduce the plant height of rice without affecting the yield per plant, and can be used to reduce the plant height of hybrid rice.

[0073] Table 2 Yield performance of LYP9 and YLY6 and their improved hybrid rice

[0074]

[0075] and respectively indicate significant differences at the P ≤0.05 and P ≤0.01 levels.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Use of the PH8 protein, or its coding gene, or a biological material containing its coding gene in regulating the plant height, panicle length or lodging resistance of plants; the PH8 protein is cytochrome P450 CYP78A15, and the plant is a plant of the genus Oryza; The PH8 protein is as shown in SEQ ID NO.1, and the regulation of the plant height, panicle length or lodging resistance of plants is: by reducing the expression level of the PH8 protein in the plant, reducing the plant height and panicle length of the plant, and improving the lodging resistance of the plant.

2. Use of inhibiting the expression of the PH8 protein, or its coding gene in cultivating plants with strong dwarfing, short panicle length or lodging resistance; the PH8 protein is cytochrome P450 CYP78A15, and the plant is a plant of the genus Oryza; The PH8 protein is as shown in SEQ ID NO.1; The inhibition is gene knockout using the CRISPR-Cas9 gene editing system with the PH8 protein as the target.

3. Use of the PH8 protein, or its coding gene, or a biological material containing its coding gene in improving plant germplasm resources related to lodging resistance; the PH8 protein is cytochrome P450 CYP78A15, and the plant is a plant of the genus Oryza; the improvement is: by reducing the expression level of the PH8 protein in the plant, reducing the plant height and panicle length of the plant, and improving the lodging resistance of the plant; The PH8 protein is as shown in SEQ ID NO.

1.

4. The application according to any one of claims 1 to 3, characterized in that, By introducing the nucleotide sequence shown in SEQ ID NO.3 into the plant, the plant height of the plant is reduced and the lodging resistance of the plant is improved.

5. The application according to any one of claims 1 to 3, characterized in that The coding gene of the PH8 protein includes the nucleotide sequence shown in SEQ ID NO.

2.

6. The application according to any one of claims 1-3, characterized in that, The biological material is an expression cassette, a vector or a transgenic cell.

7. A nucleic acid for reducing the plant height of Oryza plants, characterized in that, The nucleic acid is as shown in SEQ ID NO.

3.

8. A method for reducing the plant height, characterized in that Including: Introducing the nucleic acid according to claim 7 into the plant; the plant is a plant of the genus Oryza.

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