Search

EP-2451268-B1 - SOYBEAN SEED POPULATION, SOYBEAN PLANTS AND OIL PRODUCED THEREFROM

EP2451268B1EP 2451268 B1EP2451268 B1EP 2451268B1EP-2451268-B1

Inventors

  • BILYEU, KRISTIN
  • SHANNON, GROVER
  • LEE, JEONG-DONG
  • PHAM, TUNG, ANH

Dates

Publication Date
20260506
Application Date
20100708

Claims (11)

  1. A population of soybean seeds providing stably reproducing soybean plants, comprising a first polynucleotide sequence encoding a mutant FAD2-1A and a second polynucleotide sequence encoding a mutant FAD2-1B, wherein said first polynucleotide sequence is selected from the group consisting of (a) a polynucleotide sequence encoding a FAD2-1A mutant which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 117 of SEQ ID NO: 10, and (b) a polynucleotide sequence encoding M23 mutant characterized by deletion of a FAD2-1A gene having the sequence as set forth in SEQ ID NO: 5, said FAD2-1A mutant is nonfunctional or has a reduced activity compared to wild-type FAD2-1A; and said second nucleotide sequence being a polynucleotide sequence encoding a FAD2-1B mutant which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 137 of SEQ ID NO: 12,, wherein said FAD2-1B mutant is nonfunctional or has reduced activity compared to wild-type FAD2-1B, wherein oil from said population of soybean seeds has about 65% to about 85% oleic acid content.
  2. The population of soybean seeds of claim 1, wherein said first polynucleotide sequence encodes a nonfunctional FAD2-1A mutant or a FAD2-1A mutant having a reduced activity compared to wild-type FAD2-1A which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 117 of SEQ ID NO: 10; preferably, said non-conserved amino acid substitution being an amino acid substitution of serine to asparagine at position 117 of SEQ ID NO: 10 (S117N).
  3. The population of soybean seeds of claim 2, wherein said second polynucleotide sequence encodes a nonfunctional FAD2-1B mutant or a FAD2-1B mutant having a reduced activity compared to wild-type FAD2-1B which includes at least one mutation comprising a polar amino acid at position 137 of SEQ ID NO: 12; preferably, said polar amino acid being selected from the group consisting of arginine, glycine, serine, threonine, cysteine, asparagine, tyrosine, glutamine, lysine and histidine; more preferably, said at least one mutation comprising an amino acid substitution of proline to arginine at position 137 of SEQ ID NO: 12 (P137R).
  4. The population of soybean seeds of claim 1, wherein said first polynucleotide sequence encodes M23 mutant characterized by deletion of a FAD2-1A gene having the sequence as set forth in SEQ ID NO: 5, and wherein said second polynucleotide sequence encodes a nonfunctional FAD2-1B mutant or a FAD2-1B mutant having a reduced activity compared to wild-type FAD2-1B which includes at least one mutation comprising a polar amino acid at position 137 of SEQ ID NO: 12; preferably, said polar amino acid being selected from the group consisting of arginine, glycine, serine, threonine, cysteine, asparagine, tyrosine, glutamine, lysine and histidine; more preferably, said at least one mutation comprising an amino acid substitution of proline to arginine at position 137 of SEQ ID NO: 12 (P137R).
  5. A soybean plant grown from a soybean seed of the population according to any one of claims 1 to 4.
  6. Oil made from a population of soybean seeds according to any one of claims 1 to 4, wherein said oil comprises a detectable amount of said first and second polynucleotide sequences and has from about 65% to about 85% oleic acid content.
  7. A soybean plant with seed having a higher oleic acid content compared to a wild-type soybean plant, produced by a method comprising: (1) crossing the soybean plant of claim 5 with another soybean plant to produce progeny; and (2) preserving about 65% to about 85% oleic acid as a trait in said progeny determined by breeder selection to comprise said first and second polynucleotide sequences, thereby producing a soybean plant with seed having a higher oleic acid content compared to a wild-type plant.
  8. A soybean plant with seed having an oleic acid content of between about 65% to about 85%, produced by a method comprising: (1) crossing a first soybean plant comprising a first polynucleotide sequence selected from the group consisting of (a) a polynucleotide sequence encoding a FAD2-1A mutant which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 117 of SEQ ID NO: 10, and (b) a polynucleotide sequence encoding M23 mutant characterized by deletion of a FAD2-1A gene having the sequence as set forth in SEQ ID NO: 5, wherein said FAD2-1A mutant is nonfunctional or has a reduced activity compared to wild-type FAD2-1A, with a second soybean plant comprising a second nucleotide sequence being a polynucleotide sequence encoding a FAD2-1B mutant which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 137 of SEQ ID NO: 12, wherein said FAD2-1B mutant is nonfunctional or has reduced activity compared to wild-type FAD2-1B; and (2) selecting for a progeny soybean plant that comprises said first and second polynucleotide sequences, thereby producing a soybean plant with seed having an oleic acid content of between about 65% to about 85%.
  9. The soybean plant of claim 8, wherein said first polynucleotide sequence encodes a nonfunctional FAD2-1A mutant or a FAD2-1A mutant having a reduced activity compared to wild-type FAD2-1A which includes at least one mutation comprising a non-conserved amino acid substitution at amino acid position 117 of SEQ ID NO: 10.
  10. The soybean plant of claim 9, wherein said second polynucleotide sequence encodes a nonfunctional FAD2-1B mutant or a FAD2-1B mutant having a reduced activity compared to wild-type FAD2-1B which includes at least one mutation comprising a polar amino acid at position 137 of SEQ ID NO: 12; preferably, said polar amino acid being selected from the group consisting of arginine, glycine, serine, threonine, cysteine, asparagine, tyrosine, glutamine, lysine and histidine; more preferably, said at least one mutation comprising an amino acid substitution of proline to arginine at position 137 of SEQ ID NO: 12 (P137R).
  11. The soybean plant of claim 8, wherein said first polynucleotide sequence encodes M23 mutant characterized by deletion of a FAD2-1A gene having the sequence as set forth in SEQ ID NO: 5, and wherein said second polynucleotide sequence encodes a nonfunctional FAD2-1B mutant or a FAD2-1B mutant having a reduced activity compared to wild-type FAD2-1B which includes at least one mutation comprising a polar amino acid at position 137 of SEQ ID NO: 12; preferably, said polar amino acid being selected from the group consisting of arginine, glycine, serine, threonine, cysteine, asparagine, tyrosine, glutamine, lysine and histidine; more preferably, said at least one mutation comprising an amino acid substitution of proline to arginine at position 137 of SEQ ID NO: 12 (P137R).

Description

FIELD This application relates to a population of soybean seeds as well as to as soybean plants and oil produced therefrom. BACKGROUND Plant oils are used in a variety of applications. Novel vegetable oil compositions and improved approaches to obtain oil compositions, from biosynthetic or natural plant sources, are needed. Depending upon the intended oil use, various different fatty acid compositions are desired. Plants, especially species which synthesize large amounts of oils in seeds, are an important source of oils both for edible and industrial uses. Oleic acid is a monounsaturated omega-9 fatty acid found in various animal and vegetable sources. It is considered one of the healthier sources of fat in the diet and is commonly used as a replacement for fat sources that are high in saturated fats. Diets in which fat consumption are high in oleic acid have been shown to reduce overall levels of cholesterol, arteriosclerosis and cardiovascular disease. Specifically, oleic acid has been shown to raise levels of high-density lipoproteins (HDLs) known as "good cholesterol", while lowering low-density lipoproteins (LDLs) also known as the "bad" cholesterol. Thus, the development of new and inexpensive sources of foods comprising healthier forms of fatty acid is desirable. Plants synthesize fatty acids via a common metabolic pathway known as the fatty acid synthetase (FAS) pathway. Beta-ketoacyl-ACP (acyl carrier protein moiety) synthases are important rate-limiting enzymes in the FAS of plant cells and exist in several versions. Beta-ketoacyl-ACP synthase I catalyzes chain elongation to palmitoyl-ACP (C16:0), whereas Beta-ketoacyl-ACP synthase II catalyzes chain elongation to stearoyl-ACP (C18:0). Beta-ketoacyl-ACP synthase IV is a variant of Beta-ketoacyl-ACP synthase II, and can also catalyze chain elongation to 18:0-ACP. In soybeans, the major products of FAS are 16:0-ACP and 18:0-ACP. The desaturation of 18:0-ACP to form 18:1-ACP is catalyzed by a plastid-localized soluble delta-9 desaturase (also referred to as "stearoyl-ACP desaturase"). The products of the plastidial FAS and delta-9 desaturase, 16:0-ACP, 18:0-ACP, and 18:1-ACP, are hydrolyzed by specific thioesterases (FAT). Plant thioesterases can be classified into two gene families based on sequence homology and substrate preference. The first family, FATA, includes long chain acyl-ACP thioesterases having activity primarily on 18:1-ACP. Enzymes of the second family, FATB, commonly utilize 16:0-ACP (palmitoyl-ACP), 18:0-ACP (stearoyl-ACP), and 18:1-ACP (oleoyl-ACP). Such thioesterases have an important role in determining chain length during de novo fatty acid biosynthesis in plants, and thus these enzymes are useful in the provision of various modifications of fatty acyl compositions, particularly with respect to the relative proportions of various fatty acyl groups that are present in seed storage oils. The products of the FATA and FATB reactions, the free fatty acids, leave the plastids and are converted to their respective acyl-CoA esters. Acyl-CoAs are substrates for the lipid-biosynthesis pathway (Kennedy Pathway), which is located in the endoplasmic reticulum (ER). This pathway is responsible for membrane lipid formation as well as the biosynthesis of triacylglycerols, which constitute the seed oil. In the ER there are additional membrane-bound desaturases, which can further desaturate 18:1 to polyunsaturated fatty acids. The soybean genome possesses two seed-specific isoforms of a delta-12 desaturase FAD2, designated FAD2-1A and FAD2-1B, which differ at only 24 amino acid residues. The genes encoding FAD2-1A and FAD2-1B are designated Glyma10g42470 on Linkage Group O and Glyma 20g24530 on Linkage Group I on the soybean genome sequence, respectively (Glyma1.0, Soybean Genome Project, DoE Joint Genome Institute). FAD2-1A and FAD2-1B are found in the ER where they can further desaturate oleic acid to polyunsaturated fatty acids. The delta-12 desaturase catalyzes the insertion of a double bond into oleic acid (18:1), forming linoleic acid (18:2) which results in a consequent reduction of oleic acid levels. A delta-15 desaturase (FAD3) catalyzes the insertion of a double bond into linoleic acid (18:2), forming linolenic acid (18:3). Table 1. Characteristics of the major Fatty AcidsCarbons:Double BondsNameSaturation16:0Palmitic AcidSaturated18:0Stearic AcidSaturated18:1Oleic Acidmonounsaturated18:2Linoleic Acidω-6 polyunsaturated18:3α-Linolenic Acidω-3 polyunsaturated The designations (18:2), (18:1), (18:3), etc., refer to the number of carbon atoms in the fatty acid chain and the number of double bonds therein, Table 1. As used herein, the designations sometimes take the place of the corresponding fatty acid common name. For example, oleic acid (18:1) contains 18 carbon atoms and 1 double bond, and is sometimes referred to as simply "18:1". While previous research has demonstrated the important role of the FAD2-1A gene for increasing oleic acid,