CN-121992016-A - Application of PHR2 in regulation and control of nodulation and nitrogen fixation process of leguminous plants under phosphorus starvation stress

CN121992016ACN 121992016 ACN121992016 ACN 121992016ACN-121992016-A

Abstract

The invention relates to the technical field of biology, and discloses an application of PHR2 in regulating and controlling nodulation and nitrogen fixation processes of leguminous plants under phosphorus starvation stress, wherein the application is any one of P1 in enhancing nitrogen fixation capacity of leguminous plants under phosphorus starvation stress, P2 in promoting formation of rhizobium of leguminous plants with nitrogen fixation capacity under phosphorus starvation stress, P3 in improving activity of nitrogen fixation enzyme in rhizobium of leguminous plants under phosphorus starvation stress, and P4 in breeding of leguminous plants. PHR2 protein and related biological materials can be used for regulating and controlling nitrogen fixation capacity of leguminous plants under phosphorus starvation stress.

Inventors

FENG JIAN
FAN ZHIBIN
WU YAORONG
XU XIAOCAN
GUO HONGWEI
Mo Honghai
LI SANYUE

Assignees

中国科学院遗传与发育生物学研究所

Dates

Publication Date: 20260508
Application Date: 20260121

Claims (10)

1. The use of a substance that reduces the activity or content of protein PHR2, or a substance that inhibits or reduces the expression of the gene encoding said protein PHR2, characterized in that said use is any one of the following: p1, enhancing the nitrogen fixation capacity of leguminous plants under the stress of phosphorus starvation; P2, promoting leguminous plants to have nitrogen fixation capability under the stress of phosphorus starvation; p3, improving the activity of the nitrogen fixation enzyme in the root nodule of the leguminous plant under the stress of phosphorus starvation; p4, application in leguminous plant breeding; The protein PHR2 is the protein of A1), A2) or A3) as follows: A1 A protein having an amino acid sequence of SEQ ID No. 2; A2 A protein which is derived from A1) or has 80% or more identity with the protein shown in A1) and has the same function and is obtained by substituting and/or deleting and/or adding more than one amino acid residue into the amino acid sequence shown in A1); A3 Fusion proteins obtained by ligating protein tags at the N-terminal or/and C-terminal of A1) and A2).
2. The method according to claim 1, wherein the PHR2 protein is a DNA molecule represented by the following a 1), a 2) or a 3): a1 A DNA molecule with a coding sequence shown as SEQ ID No.1 in a sequence table; a2 A DNA molecule having 90% or more identity to the nucleotide sequence defined in a 1) and encoding said protein PHR 2; a3 A DNA molecule which hybridizes under stringent conditions to the nucleotide sequence defined under a 1) or a 2) and which codes for said protein PHR 2.
3. The use according to any one of claims 1 to 2, wherein the substance that reduces the activity or content of the protein PHR2 or that inhibits or reduces the expression of the gene encoding the protein PHR2 is any one of the following c 1) to c 4): c1 A nucleic acid molecule that inhibits or reduces expression of a gene encoding PHR2 of the protein; c2 An expression cassette comprising c 1) said nucleic acid molecule; c3 A recombinant vector comprising c 1) said nucleic acid molecule, or a recombinant vector comprising c 2) said expression cassette; c4 A recombinant microorganism comprising c 1) said nucleic acid molecule, or a recombinant microorganism comprising c 2) said expression cassette, or a recombinant microorganism comprising c 3) said recombinant vector.
4. The method according to claim 3, wherein the nucleic acid molecule according to c 1) is a nucleic acid molecule targeting the gene encoding PHR2 protein according to any one of claims 1-3.
5. The method according to claim 1 to 4, wherein the leguminous plant is alfalfa.
6. The method according to claim 5, wherein the leguminous plant is alfalfa (Medicago truncatula) or alfalfa (Medicago littoralis) in a cluster.
7. A method for enhancing nitrogen fixation under phosphorus starvation stress of leguminous plants, which is characterized by comprising enhancing nitrogen fixation under phosphorus starvation stress of leguminous plants by inhibiting or reducing expression level of a gene encoding the protein PHR2 as claimed in claim 1 in genome of plants.
8. A method for promoting the formation of nitrogen-fixing nodules in leguminous plants under phosphorus starvation stress, which comprises inhibiting or reducing the expression level of the gene encoding PHR2 protein of claim 1 in the genome of the plant to promote the formation of nitrogen-fixing nodules in leguminous plants under phosphorus starvation stress.
9. A method for improving the activity of leguminous plant root nodule azotase under phosphorus starvation stress, which is characterized by comprising the step of improving the activity of leguminous plant root nodule azotase under phosphorus starvation stress by inhibiting or reducing the expression level of a coding gene of the protein PHR2 as claimed in claim 1 in a plant genome.
10. The method according to any one of claims 7 to 9, wherein the method comprises introducing into the plant a substance that decreases the activity or amount of the protein PHR2 of claim 1 or a substance that decreases the expression of the gene encoding the protein PHR2 of claim 1, wherein the substance that decreases the activity or amount of the protein PHR2 of claim 1 or the substance that decreases the expression of the gene encoding the protein PHR2 of claim 1 is any one of the following c 1) to c 4): c1 A nucleic acid molecule that inhibits or reduces expression of a gene encoding PHR2 of the protein; c2 An expression cassette comprising c 1) said nucleic acid molecule; c3 A recombinant vector comprising c 1) said nucleic acid molecule, or a recombinant vector comprising c 2) said expression cassette; c4 A recombinant microorganism comprising c 1) said nucleic acid molecule, or a recombinant microorganism comprising c 2) said expression cassette, or a recombinant microorganism comprising c 3) said recombinant vector.

Description

Application of PHR2 in regulation and control of nodulation and nitrogen fixation process of leguminous plants under phosphorus starvation stress Technical Field The invention relates to the technical field of biology, in particular to an application of PHR2 in regulating and controlling nodulation and nitrogen fixation processes of leguminous plants under phosphorus starvation stress. Background The nitrogen element is taken as an essential nutrient element for plant growth and development, is an important constituent component of plant organisms and directly participates in a plurality of physiological and biochemical processes of plants. Under the condition of nitrogen deficiency, the plants can show symptoms such as yellowing of leaves, slow growth and the like. In agricultural production, insufficient nitrogen in soil is an important cause of limitation in crop yield. To ensure crop yield, a large amount of fertilizer is often applied. Excessive use of chemical fertilizers not only increases the cost of agricultural production, but also greatly influences soil and environment due to chemical fertilizer residues in the soil. In order to solve the problem of insufficient nitrogen in the soil, leguminous plants such as soybeans, alfalfa and the like can interact with rhizobium in the soil to form specific organs, namely rhizobium. Rhizobia bacteria colonized therein are capable of converting atmospheric nitrogen into ammonia for uptake and utilization by plants, a process known as biosolidation. The biological nitrogen fixation needs to be carried out with a great deal of energy consumption, so that the generation of nitrogen fixation reaction needs the plants to provide a great deal of phosphorus elements. However, under natural conditions, most of the phosphorus in the soil forms insoluble salts with metal ions, which reduces the solubility and mobility of phosphorus and is unfavorable for the effective utilization of phosphorus in the soil by plants. This makes phosphorus a major factor limiting biological nitrogen fixation reactions. In recent years, important progress has been made in the research on the molecular mechanism of root nodule symbiosis establishment, but the molecular mechanism of plant regulation of root nodule symbiosis under phosphorus starvation conditions is not clear. Therefore, there is a need in the art to develop intensive research into the molecular mechanism of root nodule symbiosis of plants under nitrogen and phosphorus starvation conditions to clarify the regulation of root nodule symbiosis by the nutritional status of the plants. Disclosure of Invention Under the condition of nitrogen and phosphorus starvation, rhizobium infection and rhizobium formation of plants can be obviously inhibited, and the occurrence of subsequent biological nitrogen fixation reaction is further affected. The resistance of nitrogen fixation reaction can cause the problem that plants face insufficient nitrogen supply, and further inhibit the growth and development of the plants. The technical problem to be solved by the present invention is therefore how to increase the tolerance of leguminous plants to nitrogen and phosphorus starvation conditions during interaction with rhizobia. In order to solve the above technical problems, there is provided, first of all, an agent for reducing the activity or content of PHR2 protein, or an application for inhibiting or reducing the expression of PHR2 protein-encoding gene, wherein the application is any of the following: p1, enhancing the nitrogen fixation capacity of leguminous plants under the stress of phosphorus starvation; P2, promoting leguminous plants to have nitrogen fixation capability under the stress of phosphorus starvation; p3, improving the activity of the nitrogen fixation enzyme in the root nodule of the leguminous plant under the stress of phosphorus starvation; p4, application in leguminous plant breeding; The protein PHR2 may be a protein of the following A1), A2) or A3): A1 A protein having an amino acid sequence of SEQ ID No. 2; A2 A protein which is derived from A1) or has 80% or more identity with the protein shown in A1) and has the same function and is obtained by substituting and/or deleting and/or adding more than one amino acid residue into the amino acid sequence shown in A1); A3 Fusion proteins obtained by ligating protein tags at the N-terminal or/and C-terminal of A1) and A2). In the above application, the protein PHR2 may be derived from alfalfa (Medicago littoralis) in a string form. In the above application, the gene encoding the protein PHR2 may be a DNA molecule as shown in a 1), a 2) or a 3) as follows: a1 A DNA molecule with a coding sequence shown as SEQ ID No.1 in a sequence table; a2 A DNA molecule having 90% or more identity to the nucleotide sequence defined in a 1) and encoding the above-described protein PHR 2; a3 A DNA molecule which hybridizes under stringent conditions to the nucleotide sequence defined under