JP-2022515435-A5 -

Dates

Publication Date

20221223

Application Date

20191216

Description

Table 2 Details of NtNIA2-specific primers The reported details are the sequence of the NtNIA2-specific primer. The second column shows the DNA sequence of the primer. Another aspect of the present invention may be as follows: [1] A plant cell, (a) A polynucleotide sequence encoding a nitrate reductase polypeptide comprising the sequence of sequence number 5 or sequence number 7, wherein methionine is substituted with an amino acid that reduces nitrate reductase activity in the plant cells compared to control plant cells. (b) A polypeptide sequence encoded by the polynucleotide sequence described in (a), or (c) A construct, vector, or expression vector comprising the polynucleotide sequence described in (b) Plant cells, including those mentioned above. [2] The plant cell according to [1], wherein methionine is substituted with a different amino acid, preferably isoleucine, and preferably the polypeptide comprises a continuous polypeptide sequence of SEQ ID NO: 6 or SEQ ID NO: 8. [3] The plant cell according to [1] or [2], wherein the nitrate reductase polypeptide contains an amino acid substitution at a position corresponding to the 527th position of a sequence having at least 80% sequence identity with SEQ ID NO: 1. [4] The plant cell according to any one of [1] to [3], wherein the nitrate reductase polypeptide comprises the polypeptide sequence described in SEQ ID NO: 3, or is essentially composed of the polypeptide sequence described in SEQ ID NO: 3. [5] The plant cell according to any one of [1] to [4], wherein the polynucleotide sequence comprises a polynucleotide sequence having at least 80% sequence identity with SEQ ID NO: 4, or is essentially composed of a polynucleotide sequence having at least 80% sequence identity with SEQ ID NO: 4. [6] A plant cell according to any one of [1] to [5], wherein the polynucleotide sequence comprises the polynucleotide sequence described in Sequence ID No. 4, or is essentially composed of the polynucleotide sequence described in Sequence ID No. 4. [7] The plant cell according to any one of [1] to [6] above, wherein the plant cell is a Nicotiana tabacum plant cell. [8] The plant cell according to [7], wherein the plant cell is a plant cell of the Nicotiana tabacum AA37 cultivar. [9] Preferably, a plant or part thereof containing plant cells according to any one of [1] to [8], wherein the dried leaves of the plant or part thereof contain a lower level of nitrate compared to a control plant or part thereof, and preferably, the level of nitrate is reduced compared to the control plant or part thereof. [10] Plant material, dried plant material, or homogenized plant material derived from the plant or part thereof as described in [9], preferably the dried plant material is air-dried, sun-dried, or hot air-dried, and preferably the plant material, dried plant material, or homogenized plant material includes biomass, seeds, stems, flowers, or leaves of the plant or part thereof as described in [9]. [11] A tobacco product comprising plant cells as described in any of [1] to [8] above, a part of a plant as described in [9] above, or a plant material as described in [10] above. [12] A method for producing the plant described in [9] above, (a) A step of providing plant cells according to any one of [1] to [8] above, and (b) The process of growing the plant cells in a plant. Methods that include... [13] A method for producing a dried plant material having a changed amount of nitrate compared to a control plant material, (a) A step of providing the plant or part thereof as described in [9] above, or the plant material as described in [10] above. (b) Optionally, the step of harvesting the plant material from the plant or a part thereof, and (c) A process of drying the plant material. Methods that include... [14] The method according to [13], wherein the plant material includes dried leaves. [15] The method according to [14], wherein the drying method is selected from the group consisting of air drying, thermal drying, smoke drying, and hot air pipe drying.