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EP-3690042-B1 - PARTHENOCARPY REGULATION GENE AND USE THEREOF

EP3690042B1EP 3690042 B1EP3690042 B1EP 3690042B1EP-3690042-B1

Inventors

  • FUKUOKA, HIROYUKI
  • MATSUO, SATOSHI
  • MIYATAKE, Koji
  • SHIMAKOSHI, Satoshi
  • URASHIMO, Souichi
  • ENDO, MAKOTO

Dates

Publication Date
20260506
Application Date
20150119

Claims (8)

  1. A solanaceous plant or a progeny plant thereof, each of which is a parthenocarpic plant and in each of which (i) expression of a parthenocarpy regulatory gene, which comprises a polynucleotide recited in any of (1) through (4) below, is inhibited or (ii) the function of a polypeptide, which is encoded by the parthenocarpy regulatory gene, is decreased or defective, as compared to the respective wild type plant, wherein the function of the polypeptide refers to an activity (amino group transferase activity) for catalyzing a reaction to synthesize tryptophan by transferring an amino group of an amino acid to an indole pyruvic acid (IPyA), and wherein in the amino acid sequence of the polypeptide, substitution, deletion, insertion, and/or addition of an amino acid occur(s) so as to cause the decrease or defect of the amino group transferase activity, (1) A polynucleotide that encodes a polypeptide having an amino acid sequence represented by SEQ ID NO: 1, (2) a polynucleotide that encodes a polypeptide (i) having a sequence identity of 75% or higher relative to the amino acid sequence represented by SEQ ID NO: 1 and (ii) having the parthenocarpy regulatory activity, (3) a polynucleotide that encodes a polypeptide (i) having an amino acid sequence in which 1 to 98 amino acids are substituted in, deleted from, inserted into, and/or added to the amino acid sequence represented by SEQ ID NO: 1 and (ii) having the parthenocarpy regulatory activity, and (4) a polynucleotide that (i) is hybridized with a polynucleotide, which has a sequence complementary to the polynucleotide recited in the above (1), under a stringent condition and (ii) encodes a polypeptide having the parthenocarpy regulatory activity.
  2. The solanaceous plant or the progeny plant thereof according to claim 1, wherein the expression of a parthenocarpy regulatory gene which comprises a polynucleotide recited in any of (1) through (4) above, is inhibited by a mutation on the expression adjusting sequence or the base sequence of the partenocarpy regulatory gene.
  3. The plant according to claim 1 or 2, wherein: in the reaction to synthesize tryptophan by transferring an amino group of an amino acid to an indole pyruvic acid (IPyA), at least one amino acid whose amino group is to be transferred is methionine.
  4. The plant according to any one of claims 1 to 3, wherein: the solanaceous plant is eggplant, tomato, or pepper.
  5. The plant according to any one of claims 1 to 4, wherein said plant is a plant body, a part of the plant body, or a seed of the plant body.
  6. The plant according to any one of claims 1 to 5, wherein the sequence identity relative to SEQ ID NO: 1 is 85% or higher.
  7. The plant according to any one of claims 1 to 6, wherein the sequence identity relative to SEQ ID NO: 1 is 90% or higher.
  8. The plant according to any one of claims 1 to 7, wherein in the amino acid sequence of the polypeptide, the substitution, deletion, insertion, and/or addition of an amino acid, which cause(s) decrease or a defect of the amino group transferase activity, result(s) from a termination codon at one of the amino acids at positions 42 or 43, and wherein the plant is pepper.

Description

Technical Field The present invention relates to solanaceous plant or a progeny plant thereof, each of which is a parthenocarpic plant and in each of which (i) expression of a parthenocarpy regulatory gene, which includes a polynucleotide recited in any of (1) through (4) below, is inhibited or (ii) a function of a polypeptide, which is encoded by the parthenocarpy regulatory gene, is decreased or defective, as compared with a wild type plant, wherein the function of the polypeptide refers to an activity (amino group transferase activity) for catalyzing a reaction to synthesize tryptophan by transferring an amino group of an amino acid to an indole pyruvic acid (IPyA), and wherein in the amino acid sequence of the polypeptide, substitution, deletion, insertion, and/or addition of an amino acid occur(s) so as to cause the decrease or defect of the amino group transferase activity. Background Art In solanaceous plants such as eggplant and tomato, in general, pollination is normally carried out after anthesis, and a fruit is enlarged after seeds are formed in the fruit. On the other hand, a trait with which a fruit is normally enlarged and matured without pollination and seed formation is called parthenocarpy. This trait is significantly advantageous in fields of agriculture, horticulture, and the like in terms of harvesting fruits without carrying out, for example, work such as pollination induction with the use of flower visiting insects or fructification induction by hormone drug application. Conventionally, with regard to solanaceous plants, it has been known that change in amount of auxin, which is one of phytohormones, in an ovary is one of factors for inducing parthenocarpy. For example, it is known that parthenocarpy is induced by applying a synthetic auxin to an eggplant flower or the like (Non-patent Literature 1). With regard to a synthesis mechanism, in a plant, of indole acetic acid (hereinafter, referred to as "IAA") which is one of natural auxin, there have been prior study in which Arabidopsis is used as an experimental model plant. In Arabidopsis, the existence of an IPyA pathway is known as a biosynthetic pathway. In addition, the existence of a TAM pathway, an IAM pathway, and the like is presumed. It is becoming clear that many genes are relevant to these pathways and, recently, not only a gene which encodes an enzyme that positively functions with respect to IAA synthesis but also the existence of a gene which encodes an enzyme that negatively functions have been reported. For example, Non-patent Literature 2 discloses VAS1 which catalyzes reaction to generate tryptophan by transferring an amino group from methionine to an indole pyruvic acid (IPyA) in an IPyA pathway which is one of IAA synthesis pathways of Arabidopsis. Thus, VAS1 encodes an enzyme that negatively functions with respect to IAA synthesis. Non-patent Literature 3 discloses that parthenocarpy is induced in eggplant by placenta-specific and ovule-specific expression of iaaM which is an IAA synthesis enzyme relevant to an IAM pathway that (i) is one of the IAA synthesis pathways and (ii) exists in a bacterium. Note that an experiment in Non-patent Literature 3 was carried out with the use of a plant in which excessive expression of bacterium-derived iaaM of Pseudomonas was caused under control by a snapdragon-derived promotor. Patent Literature 1 discloses Solanum tycopersicum plants carrying one or more of the pat-6, pat-7, pat-8 and pat-9 parthenocarpy genes, capable of producing seedless tomatoes. Citation List [Non-patent Literature] [Non-patent Literature 1] Nothmann et al. (1975) J. Hort. Sci. 50: 23-27[Non-patent Literature 2] Zheng et al. (2013) Nature Chem. Biol. 9: 244-246[Non-patent Literature 3] Rotino et al., (1997) Nature Biotechnology 15: 1398-1401 [Patent Literature] [Patent Literature 1] WO2009005343 A1 Summary of Invention Technical Problem As disclosed in Non-patent Literatures 2 and 3, existence of genes relevant to IAA synthesis has been known. However, the IAA synthesis mechanism is a highly complicated pathway, and it is predictable that many unknown genes play significant roles in the IAA synthesis pathway. Further, clarification of functions of the unknown genes in the IAA synthesis may lead to a highly useful technique in fields of agriculture, horticulture, and the like. Depending on cultivation conditions or cultivar lines, phenotypic expression of parthenocarpy can become unstable, and therefore it is sometimes difficult to evaluate parthenocarpy if the evaluation is based only on appearance of a plant. Moreover, in order to evaluate parthenocarpy, much manpower and time are required for emasculation before anthesis, evaluation of fruit set, and the like. Solution to Problem In order to attain the object, the present encompasses any one of the aspect defined by the claims. Any subject-matter falling outside the scope of the claims is provided for information purposes only. As illustrative informat