Method of creating a plurality of targeted insertions in a plant cell
The invention relates to novel plants, seeds and compositions, as well as improvements to plant breeding and methods for creating modifications in plant genomes.
1. A method of modifying a plant cell by creating a plurality of targeted insertions in the genome of the cell, comprising:
contacting the genome with one or more effector molecules comprising at least one site-specific double stranded break (DSB)-inducing agent which introduces a DSB at predetermined target sites located in a non-coding sequence upstream of two or more coding sequences of interest within the genome of the plant cell and one or more single-stranded DNA polynucleotide donor molecules, wherein each of at least two of the targeted insertions comprises integration of a predetermined sequence encoded by the single-stranded DNA polynucleotide donor molecule into the genome at the DSBs, wherein the predetermined sequence encoded by the single-stranded DNA polynucleotide donor molecule comprises an expression-enhancing element, wherein the polynucleotide donor molecules lack homology to the genome sequences adjacent to the sites of insertion at the DSBs, wherein the efficiency of integration of the predetermined sequence encoded by the single-stranded DNA polynucleotide donor molecule is increased relative to the same predetermined sequence encoded by a double-stranded DNA polynucleotide donor molecule;
wherein the plurality of targeted insertions occurs without an intervening step of separately identifying an individual insertion and without a step of separately selecting for the occurrence of an individual insertion among the plurality of targeted insertions; and
wherein the targeted insertions increase expression of the coding sequences of interest, and wherein the increased expression alters at least one trait of the plant cell, or at least one trait of a plant comprising the plant cell, or at least one trait of a plant grown from the plant cell, or result in a detectable phenotype in the modified plant cell.
2. The method of claim 1 wherein the plant cell has a ploidy of 2n, with n being a value selected from the group consisting of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, and 6, and wherein the method generates 2n targeted insertions at 2n loci of the predetermined target sites within the genome.
3. The method of claim 1 , wherein said single-stranded DNA polynucleotide donor molecules have a length of at least 5 nucleotides.
4. The method of claim 1 ,
a. wherein the genome of the modified cell does not comprise a nuclease, or a selection marker, or both, stably linked integrated as a result of the targeted insertions; and/or
b. wherein the method is conducted without the use of a selection marker; and/or
c. wherein the agents employed in the method do not comprise a vector.
5. The method of claim 1 , wherein the method results in a non-transgenic plant cell containing homozygous edits, without an intervening chromosome segregation event.
6. The method of claim 1 , wherein the DSB-inducing agent is provided as a ribonucleoprotein (RNP) polynucleotide composition.
7. The method of claim 6 , wherein said RNP comprises an RNA-guided nuclease and
(a) a CRISPR RNA (crRNA) that comprises a guide RNA (gRNA), or a polynucleotide that encodes a crRNA, or a polynucleotide that is processed into a crRNA; or
(b) a single guide RNA (sgRNA) that comprises the gRNA, or a polynucleotide that encodes a sgRNA, or a polynucleotide that is processed into a sgRNA.
8. The method of claim 1 , wherein the modified plant cell is a meristematic cell, embryonic cell, or germline cell.
9. The method of claim 1 , wherein repetition of the method results in an efficiency of at least 1%, wherein said efficiency is determined by dividing the number of successfully targeted cells by the total number of cells targeted.
10. The method of claim 1 , wherein at least one of the targeted insertions is between at least 3 and 400 nucleotides in length.
11. The method of claim 1 , wherein at least one of the targeted insertions is between 10 and 350 nucleotides in length.
12. The method of claim 1 , wherein
(a) the at least one DSB is two blunt-ended DSBs, resulting in deletion of genomic sequence between the two blunt-ended DSBs, and wherein the single-stranded DNA polynucleotide donor molecule is integrated into the genome between the two blunt-ended DSBs; or
(b) the at least one DSB is two DSBs, wherein the first DSB is blunt-ended and the second DSB has an overhang, resulting in deletion of genomic sequence between the two DSBs, and wherein the single-stranded DNA polynucleotide donor molecule is integrated into the genome between the two DSBs; or
(c) the at least one DSB is two DSBs, each having an overhang, resulting in deletion of genomic sequence between the two DSBs, and wherein the single-stranded DNA polynucleotide donor molecule is integrated into the genome between the two DSBs.
13. The method of claim 1 , wherein the single-stranded DNA donor polynucleotide is tethered to a crRNA by a covalent bond, a non-covalent bond, or a combination of covalent and non-covalent bonds.
14. The method of claim 1 , wherein the genome of the modified plant cell has not more unintended changes in comparison to the genome of the original plant than 2×10 −9 mutations per bp per replication.
15. The method of claim 1 , wherein the DSB-inducing agent is selected from the group consisting of:
(a) a nuclease selected from the group consisting of an RNA-guided nuclease, an RNA-guided DNA endonuclease, a type II Cas nuclease, a Cas9, a type V Cas nuclease, a Cpf1, a CasY, a CasX, a C2c1, a C2c3, an engineered nuclease, a codon-optimized nuclease, a zinc-finger nuclease (ZFN), a transcription activator-like effector nuclease (TAL-effector nuclease), an Argonaute, a meganuclease, and an engineered meganuclease;
(b) a polynucleotide encoding one or more nucleases of (a); and
(c) a guide RNA (gRNA) for an RNA-guided nuclease or a DNA encoding a gRNA for an RNA-guided nuclease when the nuclease of (a) or (b) is the RNA-guided nuclease, RNA-guided DNA endonuclease, type II Cas nuclease, Cas9 nuclease, type V Cas nuclease, Cpf1, CasY, CasX, C2c1, C2c3, engineered nuclease, or codon-optimized nuclease.
16. The method of claim 1 , wherein at least one DSB is introduced into the genome by at least one treatment selected from the group consisting of:
(a) bacterially mediated transfection;
(b) biolistics or particle bombardment;
(c) treatment with at least one chemical, enzymatic, or physical agent; and
(d) application of heat or cold, ultrasonication, centrifugation, positive or negative pressure, cell wall or membrane disruption or deformation, or electroporation.
17. The method of claim 1 , wherein a polynucleotide molecule, when integrated into the genome, is functionally or operably linked to the sequence of interest.
18. The method of claim 1 further comprising obtaining a plant from the modified plant cell.
19. The method of claim 1 , wherein the modified plant cell is identical to the original plant cell but for (i) the targeted insertions, (ii) mutations arising naturally during mitotic propagation, and optionally, (iii) any off-target mutations.
20. A method of manufacturing a commercial seed, comprising:
(a) engineering a plant cell according to the method of claim 1 ,
(b) growing a modified plant from said plant cell, and optionally further multiplying or propagating said plant, and
(c) using said plant to produce commercial seed.
21. A modified plant or plant part derived from the modified cell resulting from the method of claim 1 .
22. A method of manufacturing a plant comprising a modified cell, wherein said modified cell is generated by the method of claim 1 .
23. A method of manufacturing a plant comprising growing a plant from a modified cell, wherein said modified cell is generated by the method of claim 1 .