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CN-122012585-A - Application of CmBt and CmBr genes in regulating and controlling bitter taste of melon fruits

CN122012585ACN 122012585 ACN122012585 ACN 122012585ACN-122012585-A

Abstract

The invention relates to the technical field of plant genetic engineering and molecular breeding, in particular to application of CmBt and CmBr genes in regulating and controlling the bitter taste of melon fruits, discloses physical interaction between the proteins CmBt and CmBr of the bitter taste regulating factors of the melon fruits and cooperatively activates the expression of key genes CmBi for bitter taste synthesis, constructs CmbtCmbr double mutants through a gene editing technology, proves that double gene knockout has a synergistic effect, can remarkably reduce the content of cucurbitacin B in various tissues of the melon, and provides effective gene resources and germplasm materials for solving the industrial problem that the fruits become bitter due to the use of plant growth regulators in the melon production, wherein the effect is remarkably superior to that of single gene mutants due to complete disappearance of the bitter taste of the fruits of the CmbtCmbr double mutants under the induction of forchlorfenuron.

Inventors

  • ZHANG HUIMIN
  • CHEN XINXIU
  • WANG XINRU
  • YU TAO
  • HU MINGHE
  • ZHANG ZHONGHUA
  • XU YUANCHAO
  • WANG MINGYAN
  • WANG SHIQI
  • WANG CHUANGJIANG
  • ZHAO XUE

Assignees

  • 青岛农业大学

Dates

Publication Date
20260512
Application Date
20260211

Claims (8)

  1. Application of CmBt and CmBr genes in regulating and controlling bitter taste of melon fruits.
  2. Use of cmbt and CmBr genes, gene editing vectors containing targeted CmBt and CmBr genes, expression cassettes or transgenic cell lines for the cultivation of non-bitter melon germplasm.
  3. 3. Use according to claim 1 or 2, characterized in that the CmBt and CmBr genes are simultaneously suppressed, silenced or knocked out in melon plants; alternatively, the CmBt and CmBr proteins are subjected to loss-of-function mutations.
  4. 4. The application according to claim 1 or 2, characterized in that it comprises: Reducing or eliminating bitter taste of melon fruits, or reducing or eliminating bitter taste induced by plant growth regulator forchlorfenuron.
  5. Application of CmBt protein and CmBr protein in regulating and controlling expression of cucurbitacin B synthetic gene CmBi.
  6. 6. A method for cultivating the germplasm of a melon without bitter taste is characterized by comprising the steps of enabling CmBt genes and CmBr genes in the genome of a melon plant to have function deletion simultaneously through gene editing, mutagenesis or crossbreeding to obtain a melon CmbtCmbr double mutant material.
  7. 7. A melon CmbtCmbr double mutant material cultivated by the method of cultivating a bitterless melon germplasm of claim 6.
  8. 8. Use of the melon CmbtCmbr double mutant material of claim 7 in breeding against CPPU induced bitter.

Description

Application of CmBt and CmBr genes in regulating and controlling bitter taste of melon fruits Technical Field The invention relates to the technical field of plant genetic engineering and molecular breeding, in particular to application of CmBt and CmBr genes in regulating and controlling bitter taste of melon fruits. Background Melon (cutemis melol.) and x=2n=24, annual herbaceous plants of Cucumis sativus genus of cucurbitaceae family, are important commercial crops widely planted worldwide. In melon facilities, in order to overcome fruit setting difficulties caused by adverse environmental conditions such as low temperature, weak light and the like, a plant growth regulator Chlorpyrimide (CPPU) is often used for promoting fruit setting and improving yield. However, CPPU treatment tends to induce abnormal accumulation of cucurbitacin B in the fruit. Because the bitter taste of melon fruits is mainly caused by cucurbitacin B (Cucurbitacin B, cuB), CPPU treatment can cause the melon fruits to become bitter, which seriously affects the quality of the melon fruits, reduces the acceptance of consumers and reduces commodity value. The existing research shows that the biosynthesis of cucurbitacin B is regulated by a plurality of transcription factors. In the past, bHLH transcription factor CmBt was thought to regulate primarily fruit bitter taste, while its cognate gene CmBr was thought to regulate primarily root bitter taste. Although improvement of a single gene (e.g., cmBr) can reduce bitterness to some extent, under extreme conditions such as high-concentration CPPU treatment, single-gene mutants may still exhibit a certain proportion of bitter fruit rate or residual bitterness, and the effect of completely eliminating the bitterness cannot be achieved. Therefore, analyzing the fine regulation mechanism of CPPU induced bitterness, digging the gene combination which can completely block the bitter synthesis, has important significance for cultivating high-quality melon varieties. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide the application of CmBt and CmBr genes in regulating and controlling the bitter taste of melon fruits so as to eliminate the bitter taste of melon and apply the application to cultivation of high-quality melon varieties. In order to solve the problems, the invention adopts the following technical scheme: Use of CmBt and CmBr genes for regulating bitter taste of melon fruits. Use of CmBt and CmBr genes, a gene editing vector containing targeted CmBt and CmBr genes, an expression cassette or a transgenic cell line for breeding non-bitter melon germplasm. Further, by simultaneously inhibiting, silencing or knocking out CmBt and CmBr genes in melon plants; alternatively, the CmBt and CmBr proteins are subjected to loss-of-function mutations. Further, the application includes: Reducing or eliminating bitter taste of melon fruits, or reducing or eliminating bitter taste induced by plant growth regulator forchlorfenuron. The CmBt protein and CmBr protein are applied to regulating and controlling the expression of the cucurbitacin B synthetic gene CmBi. A method for culturing the germplasm of non-bitter melon includes such steps as gene editing, mutation or cross breeding to make CmBt and CmBr genes in the genome of melon plant have function deletion at the same time, and obtaining the CmbtCmbr double mutant of melon. Melon CmbtCmbr double mutant materials cultivated by the method for cultivating the germplasm of the melon without bitter taste. The melon CmbtCmbr double mutant material is applied to anti-CPPU induced bitter breeding. The invention has the beneficial effects that: (1) The function of CmBt is modified, cmBt is the main regulating factor of blade bitter. The prior art generally considers CmBt to be a fruit-specific regulatory factor, and the invention discovers that the CmBt gene presents high abundance expression in young melon leaves and the expression level is obviously higher than that of the homologous gene CmBr through high-throughput transcriptome sequencing and RT-qPCR analysis. The CmBt single gene knockout not only reduces the bitter taste of fruits, but also leads to the rapid decrease of the cucurbitacin B (CuB) content in leaves, and produces a phenotype without bitter leaves. The discovery corrects the cognitive deviation of CmBt for regulating fruits in the field for a long time, and provides a theoretical basis for the accurate improvement of the bitter taste of the muskmelon. The double mutant strategy is based on accurate analysis of CmBt and CmBr tissue specific functions, so that the regulation and control of the muskmelon CuB content are realized. (2) CmBt and CmBr are synergistic and do not affect melon quality while removing bitter taste more efficiently. Compared with the prior art, the invention utilizes the synergistic effect of CmBt and CmBr. The field test data showed that under CPPU induction, the Wild Type