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CN-115627273-B - Nitrate reductase gene and application thereof as plant stress resistance regulation target

CN115627273BCN 115627273 BCN115627273 BCN 115627273BCN-115627273-B

Abstract

The invention provides a nitrate reductase gene and application thereof as a plant stress-resistance regulation target. The invention discloses a novel nitrate reductase gene for regulating and controlling the nitrogen utilization efficiency of plants, which is called NR1.2.NR1.2 is closely related to drought tolerance traits of plants, and after the expression/activity of NR1.2 is reduced in plants, the plant height in the seedling stage of the plants is reduced, and simultaneously the drought tolerance of the plants is enhanced. Therefore, NR1.2 can be used as a target point for regulating drought tolerance of plants, and materials or methods for down-regulating NR1.2 can be applied to improvement of plant varieties.

Inventors

  • CHAO DAIYIN
  • HAN MEILING
  • WANG YALING
  • ZHANG JING
  • WANG TAO
  • TAN RUJIAO

Assignees

  • 中国科学院分子植物科学卓越创新中心

Dates

Publication Date
20260505
Application Date
20210714

Claims (10)

  1. 1. A method for regulating plant characteristics, including targeting down-regulating NR1.2 expression or activity in a plant, the characteristics being enhancing drought tolerance of the plant and reducing aerial height in plant seedling stage; the NR1.2 is polypeptide with an amino acid sequence shown as SEQ ID NO. 2, the plant is rice, and the expression or activity of NR1.2 in the down-regulated plant is the coding gene of NR 1.2.
  2. 2. The method of claim 1, wherein knocking out the NR1.2 coding gene in the plant comprises gene editing with a CRISPR system to knock out the NR1.2 coding gene, or knocking out the NR1.2 coding gene by homologous recombination.
  3. 3. The method of claim 1, wherein gene editing is performed by CRISPR method to knock out the NR1.2 encoding gene, and wherein the agent that is subjected to gene editing by CRISPR system is an sgRNA construct.
  4. 4. The method of claim 1, wherein the gene knockout is performed with primers shown in SEQ ID NO. 3-6 based on a CRISPR system targeting the coding gene of NR 1.2.
  5. 5. The method according to any one of claims 1 to 4, wherein the lowering of the height of the aerial parts of the plant in the seedling stage is lowering of the height of the aerial parts of the plant in the seedling stage under low nitrogen conditions.
  6. 6. The method of any one of claims 1-4, wherein after downregulating the activity of NR1.2 in a plant, the plant increases drought resistance by reducing nitrogen utilization efficiency during seedling.
  7. 7. Use of a NR1.2 downregulator for enhancing drought tolerance and reducing the height of an aerial part of a plant in the seedling stage of a plant or for preparing a formulation for enhancing drought tolerance and reducing the height of an aerial part of a plant in the seedling stage of a plant; the NR1.2 is polypeptide with an amino acid sequence shown as SEQ ID NO. 2, the plant is rice, and the down regulator is a reagent for knocking out an encoding gene of NR 1.2.
  8. 8. The use of claim 7, wherein the down regulator is a CRISPR gene editing agent for NR1.2 that subjects NR1.2 to a loss-of-function mutation.
  9. 9. The use according to any one of claims 7 to 8, wherein the reduction of the height of the aerial parts of the plant in the seedling stage is a reduction of the height of the aerial parts of the plant in the seedling stage under low nitrogen conditions.
  10. 10. The use according to any one of claims 7 to 8, wherein said plant has improved drought resistance by reducing nitrogen use efficiency during seedling stage after down-regulation of NR1.2 in the plant.

Description

Nitrate reductase gene and application thereof as plant stress resistance regulation target Technical Field The invention belongs to the field of plant variety improvement and stress resistance, and in particular relates to a nitrate reductase gene and application thereof as a plant stress resistance regulation target. Background With the continuous acceleration of the world urban and industrialized processes, the population continues to grow, the water and soil loss and land salinization occur, and the number of the cultivated lands in the world is continuously reduced. The problem of food shortage is a common challenge. The theoretical method of molecular genetics is utilized to deeply study the improvement of crop varieties, enhance the adaptability of crops to different environmental stresses, and realize the high and stable yield of crops, which is an important aspect in the field. Crops are often subjected to environmental stresses such as drought, high salt, high temperature and the like in the growth and development process, and the crop yield is greatly influenced. How to improve the crop yield and the resistance of the crop to environmental stress at the same time and realize the high and stable yield of the crop is a great subject faced by scientists and breeders. Gramineous rice is one of the most important food crops in the world, and is widely sown to provide staple food for half of the population in the world. However, in order to more widely realize rice cultivation and to improve its planting efficiency, how to realize improvement of its environmental suitability under different environments is a serious in the art. Some grain production data show that the grain yield per unit of large area is not significantly improved under the condition of keeping the high fertilizer input. The utilization efficiency of plant nutrients is reduced, so that the application amount of the fertilizer is gradually increased, the production cost is greatly increased, and the phenomenon of increasing yield and not increasing income is generally caused in agricultural production. On the other hand, most of nitrogen fertilizer applied in agricultural production enters the environment due to low utilization efficiency of the crop nitrogen fertilizer, and the problems of water system eutrophication, soil acidification, water resource and soil heavy metal accumulation and other environmental pollution are directly caused. So far, a plurality of puzzles still exist in a molecular mechanism affecting the utilization efficiency of plant nitrogen, and a plurality of key components involved in the utilization efficiency of plant nitrogen still need to be discovered. Under the natural condition, due to different geographical positions, climatic conditions, human activities and other reasons, various bad environments are caused, and the range of the plants which can be tolerated by normal growth and development is exceeded, so that the plants are damaged and even die. These environments that cause damage to plants are called stress, or stress. Adverse conditions include, but are not limited to, freezing, low temperature, high temperature, drought, salt, soil moisture and disease. Although the plant is subject to stress, it resists stress by physiological reaction, if beyond the sustainable range, the damage becomes irreversible and the plant is damaged or even dies beyond the self-repairing capability of the plant. Drought can lead to wilting of leaves and tender stems, and physiological and ecological changes such as reduction and even closing of stomata opening degree and the like, and the normal germination, growth and maturation of plants are greatly influenced. Drought tolerance in plants is a complex trait of polygenic control in which multiple mechanisms are involved in conjunction with signaling pathways. The signaling process involving drought stress is relatively complex, and has been interdigitated with signaling pathways that are also resistant to heat, freezing, and oxidative stress. Conventionally, improving drought tolerance of plants has been an important topic in the art. There is a need in the art to explore more effective ways to improve drought tolerance in plants. Disclosure of Invention The invention aims to provide a novel nitrate reductase gene for regulating and controlling the nitrogen utilization efficiency of plants. The invention also aims to provide a nitrate reductase gene and application thereof as a plant stress-resistance regulation target. The invention also aims to provide potential application of the nitrate reductase gene in enhancing the nitrogen utilization efficiency of plants. In a first aspect of the invention there is provided a method of modulating a trait in a plant comprising targeting down-regulation of expression or activity of NR1.2 in a plant, the trait comprising enhancing drought tolerance of the plant and/or reducing the aerial height (plant height) of the plant in the s