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CN-122012540-A - Osrdh mutant and application thereof in improving rice quality

CN122012540ACN 122012540 ACN122012540 ACN 122012540ACN-122012540-A

Abstract

The invention discloses Osrdh mutants and application thereof in improving rice quality. The Osrdh mutants are homozygous mutants, including Osrdh-1 mutant, osrdh-2 mutant and Osrdh-3 mutant, and are loss-of-function mutants with nucleotide deletion at target sites by targeting the first exon of the rice OsRDH gene through CRISPR/Cas9 gene editing technology. Compared with wild rice, osrdh homozygous mutant shows the synergistic improved rice quality characteristics of remarkably increased grain length, remarkably reduced chalky area and chalky whiteness, remarkably improved rice appearance quality, remarkably improved whole polished rice rate, remarkably improved rice processing quality, remarkably reduced amylose content and remarkably improved rice cooking taste quality. The invention discloses a novel function of OsRDH genes in rice quality formation for the first time, provides important gene resources and mutant materials thereof which can positively improve rice appearance quality, processing quality and cooking taste quality at the same time, and has extremely high application value in high-quality rice molecular breeding.

Inventors

  • PENG BO
  • QIU JING
  • SUN YANFANG
  • ZHOU WEI
  • WANG QUANXIU
  • ZHAO JINHUI

Assignees

  • 信阳师范大学

Dates

Publication Date
20260512
Application Date
20260215

Claims (10)

  1. 1. A Osrdh mutant whose OsRDH gene carries a nucleotide deletion mutation that results in loss of function of the OsRDH gene, and which has at least one of increased grain length, reduced chalky area, reduced chalkiness, increased whole polished rice rate, reduced amylose content as compared to wild-type rice.
  2. 2. The Osrdh mutant according to claim 1, wherein the Osrdh mutant comprises a Osrdh-1 mutant, a Osrdh-2 mutant and a Osrdh-3 mutant, wherein the nucleotide sequence of the Osrdh-1 mutant is shown in SEQ ID No. 3, the nucleotide sequence of the Osrdh-2 mutant is shown in SEQ ID No. 4 and the nucleotide sequence of the Osrdh-3 mutant is shown in SEQ ID No. 5.
  3. 3. The Osrdh mutant according to claim 1 or 2, wherein the Osrdh mutant is created by designing a OsRDH target site, targeting induction of sgRNA fusion with Cas9 protein using CRISPR/Cas9 gene editing technology, specific cleavage of one PAM site of OsRDH first exon, construction of OsRDH gene-edited expression vector PYLCRISPR/Cas9-MH (B), obtaining OsRDH gene-edited plants by agrobacterium-mediated genetic transformation, sequence identification and isolation by DNA sequencing.
  4. 4. A rice plant, tissue, cell or seed comprising the Osrdh mutant of any one of claims 1-3.
  5. 5. Use of the Osrdh mutant according to any one of claims 1 to 3 for improving rice quality, including improving rice appearance quality, improving rice processing quality, improving rice cooking taste quality and/or improving rice germplasm resources.
  6. 6. The use according to claim 5, wherein the improved rice appearance quality is manifested by an increased grain length and/or a reduced chalky area in the endosperm and/or a reduced chalky whiteness in the endosperm and a dense arrangement of starch grains in the rice.
  7. 7. The use according to claim 5, wherein the improved rice processing quality is manifested by an improved whole polished rice rate.
  8. 8. The use according to claim 5, wherein the cooked taste quality is manifested by a reduced amylose content in rice.
  9. 9. The use of claim 5, wherein the improvement of rice germplasm resources comprises treatment with ABA or GA to promote Osrdh mutant seed germination.
  10. 10. A method for improving rice quality, comprising the steps of: Introducing Osrdh mutant according to any one of claims 1-3 into target rice variety by means of hybridization, backcross or gene editing technique, screening to obtain rice quality-improved rice strain with homozygous mutation.

Description

Osrdh mutant and application thereof in improving rice quality Technical Field The invention belongs to the field of agricultural biotechnology and plant genetic breeding, and particularly relates to Osrdh mutants and application thereof in improving rice quality, in particular to improving rice appearance quality, processing quality and cooking taste quality. Background With the development of economy and society and the continuous improvement of living standard of people, consumers have higher and higher requirements on rice quality. Rice quality generally includes appearance quality, nutritional quality, processing quality, and cooking taste quality, among others. The appearance quality of rice is mainly determined by grain type (Grain size or shape), chalky (CHALKINESS) and transparency (Translucency). The processing quality of rice is mainly measured by three indexes of Brown rice rate (Brown rice), polished rice rate (MILLED RICE%) and whole polished rice rate (Head rice). The cooking taste quality refers to the organoleptic and physicochemical properties exhibited by rice during cooking, and generally includes amylose content, taste value (Taste Value, TV), gum consistency (Gel Consistency, GC) and gelatinization temperature (Gelatinization Temperature, GT). The quality of steamed taste is an important index for measuring the quality of rice, and is one of the most interesting quality traits for consumers. Retinol Dehydrogenase (RDH) is a core enzyme for vitamin a metabolism, catalyzes cascade reaction of retinol to retinol and then to retinoic acid, and the generated retinoic acid is used as a signal molecule to regulate biological processes such as energy metabolism, synthesis and decomposition and transportation of fat, protein synthesis and modification, etc., in plants, RDH isozymes (such as arabidopsis thaliana AtSDR 1) are used for generating plant-specific retinol analogues by catalyzing oxidation-reduction reaction of carotenoid derivatives (such as beta-ionone), and active oxygen (Reactive Oxygen Species, ROS) and plant hormone levels are regulated by the carotenoid derivatives. Notably, there is a cross-regulation of plant RDH metabolic networks with hormonal signals, RDH regulates ROS levels and antioxidants through its metabolites, and affects ABA and IAA biosynthesis and signal transduction, thereby synergistically regulating cell growth and differentiation. RDH is therefore a key enzyme in the metabolic processes of retinol and vitamin A, and plays an important role in the processes of cell growth and differentiation, etc. Whether OsRDH is involved in biological processes such as rice growth and development and whether it affects rice quality is unclear. Disclosure of Invention The invention aims to provide a novel technical scheme capable of synchronously and effectively improving a plurality of important quality traits (appearance, processing and cooking taste) of rice. In particular to Osrdh mutants and application thereof in improving rice quality. The above purpose is achieved by the following technical scheme: A Osrdh mutant whose OsRDH gene carries a nucleotide deletion mutation that results in loss of function of the OsRDH gene, and which has at least one of increased grain length, reduced chalky area, reduced chalkiness, increased whole polished rice rate, reduced amylose content as compared to wild-type rice. In some embodiments, the Osrdh mutants include Osrdh-1 mutant, osrdh-2 mutant, osrdh-3 mutant, wherein the Osrdh-1 mutant has a nucleotide sequence as shown in SEQ ID NO.3, the Osrdh-2 mutant has a nucleotide sequence as shown in SEQ ID NO.4, and the Osrdh-3 mutant has a nucleotide sequence as shown in SEQ ID NO. 5. In some embodiments, the Osrdh mutant is created by designing OsRDH target sites, targeting induced fusion of sgRNA and Cas9 protein using CRISPR/Cas9 gene editing technology, specific cleavage of one PAM site of the OsRDH first exon, construction of OsRDH gene-edited expression vector PYLCRISPR/Cas9-MH (B), obtaining OsRDH gene-edited plants by Agrobacterium-mediated genetic transformation, sequence identification and isolation by DNA sequencing. A rice plant, tissue, cell or seed comprising the Osrdh mutant described above. The use of the Osrdh mutant in improving rice quality, including improving rice appearance quality, improving rice processing quality, improving rice cooking taste quality, and/or improving rice germplasm resources. In some embodiments, the improved rice appearance quality is manifested by an increase in grain length, and/or a decrease in chalky area in the endosperm, and/or a decrease in chalky level in the endosperm. In some embodiments, the improved rice processing quality is manifested by an increase in whole polished rice rate. In some embodiments, the improved rice cooking taste quality is manifested by a reduced amylose content. In some embodiments, the rice germplasm resource improvement comprises treatment with ABA or GA to prom