Stabilization of RNA for exogenous RNAi agricultural applications and formulations
Compositions for providing stability to RNA may include a primary surfactant, and a metal-ion sequestrant. The primary surfactant may be a nonionic surfactant. The composition may be in a soluble liquid concentrate form and may be sufficient to provide shelf stability to RNA for one year at room temperature. Compositions for delivering RNA to a pest via exogenous, foliar application of the composition to a plant may comprise RNA; a primary surfactant; and a metal-ion sequestrant.
1 . A composition for delivering RNA to a pest via exogenous, foliar application of the composition to a plant, the composition comprising:
RNA, wherein the RNA is present in an amount from about 0.4 to about 10 percent by weight based on the total weight of the composition;
a primary surfactant, wherein the primary surfactant is a nonionic surfactant, where in the primary surfactant is present in an amount of from about 4 to about 7 percent by weight based on the total weight of the composition;
a secondary surfactant, wherein the secondary surfactant is selected from the group consisting of a cationic surfactant, a zwitterionic surfactant, an amphoteric surfactant, and combinations thereof, wherein the secondary surfactant is present in an amount of from about 0.5 to about 3 percent by weight based on the total weight of the composition; and
a metal-ion sequestrant, wherein the metal-ion sequestrant is present in an amount of from about 0.6 to about 3 percent by weight based on the total weight of the composition;
and wherein the RNA is dsRNA or single-stranded RNA; and
wherein the composition controls a plant pest or pathogen selected from the group consisting of an insect or a fungus.
2 . The composition according to claim 1 , wherein the composition is a soluble liquid concentrate.
3 . The composition according to claim 1 , further comprising one or more of the following:
a UV protectant;
at least one buffer;
at least one biological preservative;
an antifoam agent; and/or
an antifreeze agent.
4 . The composition according to claim 3 , wherein the composition comprises the UV protectant, the UV protectant being present in an amount of from about 1 to about 15 percent by weight based on the total weight of the composition, or optionally, being present in an amount of from about 1 to about 2 percent by weight based on the total weight of the composition.
5 . The composition according to claim 3 , wherein the composition comprises the UV protectant, the UV protectant comprising a UV protectant selected from the group consisting of conjugated aromatic surfactant or a polymeric surfactant containing conjugated aromatic functionalities.
6 . The composition according to claim 3 , wherein the composition comprises the UV protectant, the UV protectant comprising a sodium lignosulfonate dispersant.
7 . The composition according to claim 3 , wherein the composition comprises the at least one buffer, the at least one buffer being individually present in an amount of from about 1 to about 7 percent by weight based on the total weight of the composition, or optionally, the at least one buffer being present in an amount of from about 2 to about 5 percent by weight based on the total weight of the composition.
8 . The composition according to claim 3 , wherein the composition comprises the at least one buffer, the at least one buffer comprising monobasic potassium phosphate and dibasic potassium phosphate.
9 . The composition according to claim 3 , wherein the composition comprises the at least one biological preservative, the at least one biological preservative comprising a an active ingredient selected from the group consisting of 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT), 2-methyl-4-isothiazolin-3-one (MIT), 1,2-Benzisothiazolin-3-one (BIT), and combinations thereof.
10 . The composition according to claim 3 , wherein the composition comprises the at least one biological preservative, the at least one biological preservative being individually present in an amount of from about 0.05 to about 1 percent by weight based on the total weight of the composition.
11 . The composition according to claim 3 , wherein the composition comprises the antifoam agent, the antifoam agent being present in an amount of from about 0.025 to about 0.2 percent by weight based on the total weight of the composition, or optionally, the antifoam agent being present in an amount of from about 0.025 to about 0.1 percent by weight based on the total weight of the composition.
12 . The composition according to claim 1 , wherein the primary surfactant is selected from the group consisting of a polysorbate, an alkoxylate, a nonoxynol, a poloxamer, and combinations thereof.
13 . The composition according to claim 1 , wherein the primary surfactant is selected from the group consisting of polysorbate 20, an alkoxylated alcohol, and an alkoxylate mixture of C 12 -C 13 alcohol.
14 . The composition claim 1 , wherein the metal-ion sequestrant is present in an amount of from about 1 to about 2 percent by weight based on the total weight of the composition.
15 . The composition according to claim 1 , wherein the metal-ion sequestrant is selected from the group consisting of EDTA and an acrylate copolymer.
16 . The composition of claim 15 , wherein the metal-ion sequestrant is an acrylate copolymer.
17 . The composition according to claim 1 , wherein the secondary surfactant is present in an amount of from about 0.7 to about 2 percent by weight based on the total weight of the composition.
18 . The composition according to claim 17 , wherein the secondary surfactant is present in an amount of from about 0.8 to about 1 percent by weight based on the total weight of the composition.
19 . The composition according to claim 1 , wherein the secondary surfactant is selected from the group consisting of an alkyl ammonium halide, lauryl betaine, an amine oxide, and combinations thereof.
20 . The composition according to claim 19 , wherein the secondary surfactant comprises cetrimonium chloride.
21 . The composition of claim 1 , wherein the composition is sufficient to provide shelf stability to RNA for one year at room temperature.
22 . The composition of claim 1 , wherein, the pH of the composition remains within 2 units of the initial pH after the composition is stored for a time at a temperature selected from the group consisting of 2 weeks at −20° C., 2 weeks at −10-40° C., cycling, 2 weeks at 54° C., 8 weeks at 40° C., 4 weeks at 54° C., 8 weeks at 54° C., 1 year at room temperature, and 2 years at room temperature.
23 . The composition of claim 1 , wherein the RNA present in the composition remains within 15% of the initial concentration of RNA present in the composition as measured by HPLC, after the composition is stored for a time and at a temperature selected from the group consisting of 2 weeks at −20° C., 2 weeks at −10-40° C., cycling, 2 weeks at 54° C., 8 weeks at 40° C., 4 weeks at 54° C., 8 weeks at 54° C., 1 year at room temperature, and 2 years at room temperature.
24 . The composition of claim 1 wherein the RNA is dsRNA.