MicroRNA Compositions and Methods for Enhancing Plant Resistance to Abiotic Stress

Abstract

A method of increasing tolerance of a plant to an abiotic stress or increasing biomass, vigor or yield of a plant is disclosed. The method comprising upregulating within the plant an exogenous polynucleotide of a microRNA or a precursor thereof, wherein the microRNA is selected from the group consisting of miR-156, miR-169, miR-164, miR-159, miR-167, miR-529, miR-168, ppt-miR395, sof-miR408a, ath-miR408, miR-1039, miR-1091, miR-1118, miR-1134 and miR-1129, thereby increasing the tolerance of the plant to the abiotic stress or increasing the biomass, vigor or yield of the plant.

What is claimed is: 
     
         1 . A method of increasing tolerance of a plant to an abiotic stress or increasing biomass, vigor or yield of a plant, the method comprising upregulating within the plant an exogenous polynucleotide of a microRNA or a precursor thereof, wherein said microRNA is selected from the group consisting of miR-156, miR-169, miR-164, miR-159, miR-167, miR-529, miR-168, ppt-miR395, sof-miR408a, ath-miR408, miR-1039, miR-1091, miR-1118, miR-1134 and miR-1129, thereby increasing the tolerance of the plant to the abiotic stress or increasing the biomass, vigor or yield of the plant. 
     
     
         2 . The method of  claim 1 , wherein said upregulating is effected by expressing within the plant said exogenous polynucleotide of said microRNA or said precursor thereof. 
     
     
         3 . A method of increasing tolerance of a plant to an abiotic stress or increasing biomass, vigor or yield of a plant, the method comprising expressing within the plant an exogenous polynucleotide encoding a nucleic acid agent capable of downregulating expression of a target gene of a microRNA or a precursor thereof, wherein said microRNA is selected from the group consisting of miR-156, miR-169, miR-164, miR-159, miR-167, miR-529, miR-168, ppt-miR395, sof-miR408a, ath-miR408, miR-1039, miR-1091, miR-1118, miR-1134 and miR-1129, thereby increasing the tolerance of the plant to the abiotic stress or increasing the biomass, vigor or yield of the plant. 
     
     
         4 . A method of increasing tolerance of a plant to an abiotic stress or increasing biomass, vigor or yield of a plant, the method comprising expressing within the plant an exogenous polynucleotide encoding a nucleic acid agent capable of downregulating expression or activity of a microRNA or a precursor thereof, wherein said microRNA is selected from the group consisting of miR-171, miR-172, miR-399, miR-854, miR-894, miR-160, miR-166, miR-390, ath-miR395a, smo-miR408, miR-397, miR-477, miR-528, miR-530, miR-535, miR-855, miR-894, miR-896, miR-901 and miR-1026, thereby increasing the tolerance of the plant to the abiotic stress or increasing the biomass, vigor or yield of the plant. 
     
     
         5 . A method of increasing tolerance of a plant to an abiotic stress or increasing biomass, vigor or yield of a plant, the method comprising expressing within the plant an exogenous polynucleotide for upregulating expression of a target gene of a microRNA or a precursor thereof, wherein said microRNA is selected from the group consisting of miR-171, miR-172, miR-399, miR-854, miR-894, miR-160, miR-166, miR-390, ath-miR395a, smo-miR408, miR-397, miR-477, miR-528, miR-530, miR-535, miR-855, miR-894, miR-896, miR-901 and miR-1026, thereby increasing the tolerance of the plant to the abiotic stress or increasing the biomass, vigor or yield of the plant. 
     
     
         6 . The method of any one of  claims 1 - 5 , further comprising growing the plant under abiotic stress conditions. 
     
     
         7 . The method of any one of  claims 1 - 6 , wherein said abiotic stress is selected from the group consisting of salinity, water deprivation, low temperature, high temperature, heavy metal toxicity, anaerobiosis, nutrient deficiency, nutrient excess, atmospheric pollution and UV irradiation. 
     
     
         8 . The method of any one of  claims 2 - 5 , wherein said expressing is effected by transforming a cell of said plant with said exogenous polynucleotide. 
     
     
         9 . The method of  claim 8 , wherein said transforming is effected by introducing into said cell of said plant a nucleic acid construct including said exogenous polynucleotide and at least one promoter capable of directing transcription of said exogenous polynucleotide in said cell of said plant. 
     
     
         10 . The method of any one of  claims 2 - 5 , wherein said expressing is effected by infecting said plant with a bacteria comprising said exogenous polynucleotide. 
     
     
         11 . The method of  claim 4 , wherein said downregulating activity of said microRNA is effected by introducing into said plant a target mimic or a micro-RNA resistant target which is not cleaved by said microRNA. 
     
     
         12 . The method of  claim 11 , wherein said target mimic or said micro-RNA resistant target is essentially complementary to said microRNA provided that one or more of following mismatches are allowed:
 (a) a mismatch between the nucleotide at the 5′ end of said microRNA and the corresponding nucleotide sequence in said target mimic or said micro-RNA resistant target;   (b) a mismatch between any one of the nucleotides in position 1 to position 9 of said microRNA and the corresponding nucleotide sequence in said target mimic or said micro-RNA resistant target; or   (c) three mismatches between any one of the nucleotides in position 12 to position 21 of said microRNA and the corresponding nucleotide sequence in said target mimic or said micro-RNA resistant target provided that there are no more than two consecutive mismatches.   
     
     
         13 . The method of  claim 11 , wherein said target mimic or said micro-RNA resistant target is introduced into a cell of said plant in a nucleic acid construct including a target gene and at least one promoter capable of directing transcription of said target polynucleotide in said cell of said plant. 
     
     
         14 . The method of  claim 3 ,  5  or  13 , wherein said target gene of said microRNA is as set forth in SEQ ID NOs: 195-341, 474-485. 
     
     
         15 . A nucleic acid construct, comprising a polynucleotide at least 90% homologous to a nucleic acid sequence selected from the group consisting of miR-156, miR-169, miR-164, miR-159, miR-167, miR-529, miR-168, ppt-miR395, sof-miR408a, ath-miR408, miR-1039, miR-1091, miR-1118, miR-1134 and miR-1129 or a precursor thereof, wherein said nucleic acid sequence is under a transcriptional control of at least one promoter capable of directing transcription of the polynucleotide in a host cell. 
     
     
         16 . A nucleic acid construct, comprising a polynucleotide at least 90% homologous to a nucleic acid sequence selected from the group consisting of a target gene of miR-171, a target gene of miR-172, a target gene of miR-399, a target gene of miR-854, a target gene of miR-894, a target gene of miR-160, a target gene of miR-166, a target gene of miR-390, a target gene of ath-miR395a, a target gene of smo-miR408, a target gene of miR-397, a target gene of miR-477, a target gene of miR-528, a target gene of miR-530, a target gene of miR-535, a target gene of miR-855, a target gene of miR-894, a target gene of miR-896, a target gene of miR-901 and a target gene of miR-1026, wherein said nucleic acid sequence is under a transcriptional control of at least one promoter capable of directing transcription of the polynucleotide in a host cell. 
     
     
         17 . A nucleic acid construct, comprising a nucleic acid sequence for down-regulating an expression of a target gene of a microRNA or a precursor thereof, wherein said target gene of said microRNA is selected from the group consisting of a target gene of miR-156, a target gene of miR-169, a target gene of miR-164, a target gene of miR-159, a target gene of miR-167, a target gene of miR-529, a target gene of miR-168, a target gene of ppt-miR395, a target gene of sof-miR408a, a target gene of ath-miR408, a target gene of miR-1039, a target gene of miR-1091, a target gene of miR-1118, a target gene of miR-1134 and a target gene of miR-1129, wherein said nucleic acid sequence is under a transcriptional control of at least one promoter capable of directing transcription of the polynucleotide in a host cell. 
     
     
         18 . A nucleic acid construct, comprising a nucleic acid sequence for down-regulating an expression of a microRNA or a precursor thereof, wherein said microRNA is selected from the group consisting of miR-171, miR-172, miR-399, miR-854, miR-894, miR-160, miR-166, miR-390, ath-miR395a, smo-miR408, miR-397, miR-477, miR-528, miR-530, miR-535, miR-855, miR-894, miR-896, miR-901 and miR-1026, wherein said nucleic acid sequence is under a transcriptional control of at least one promoter capable of directing transcription of the polynucleotide in a host cell. 
     
     
         19 . The nucleic acid construct of any of  claims 15 - 18 , wherein said host cell comprises a plant cell. 
     
     
         20 . The nucleic acid construct of  claim 17 , wherein said target gene of miR-169 comprises a NF-YA8 protein. 
     
     
         21 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-156 is selected from the group consisting of bna-miR156a, smo-miR156c, sbi-miR156d, smo-miR156d, vvi-miR156e, ath-miR156g, ptc-miR156k, zma-miR156k and osa-miR156l. 
     
     
         22 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-169 is selected from the group consisting of ath-miR169a, osa-miR169a, sbi-miR169b, bna-miR169c, sbi-miR169c, ath-miR169d, osa-miR169e, bna-miR169g, sbi-miR169i, bna-miR169m, vvi-miR169m, ptc-miR169o, ptc-miR169q, ptc-miR169v and ptc-miR169x. 
     
     
         23 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-164 is selected from the group consisting of osa-miR164a, sbi-miR164b, osa-miR164c, osa-miR164e and ptc-miR164f. 
     
     
         24 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-167 is selected from the group consisting of ppt-miR167, bna-miR167a, ath-miR167c, ath-miR167d, ptc-miR167f and ptc-miR167h. 
     
     
         25 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-1039 comprises ppt-miR1039-3p. 
     
     
         26 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-168 is selected from the group consisting of sbi-miR168 and gma-miR168. 
     
     
         27 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-159 is selected from the group consisting of pta-miR159c, sof-miR159c, osa-miR159c and osa-miR159d. 
     
     
         28 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-529 is selected from the group consisting of ppt-miR529a, ppt-miR529d, ppt-miR529e and ppt-miR529g. 
     
     
         29 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-1118 comprises tae-miR1118. 
     
     
         30 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-1134 comprises tae-miR1134. 
     
     
         31 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-1129 comprises tae-miR1129. 
     
     
         32 . The method of  claim 1  or  3  or nucleic acid construct of  claim 15 , wherein said miR-1091 comprises smo-miR1091. 
     
     
         33 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-171 is selected from the group consisting of smo-miR171a, vvi-miR171a, ath-miR171b, sbi-miR171b, smo-miR171b, zma-miR171c, sbi-miR171e, sbi-miR171f, zma-miR171f and vvi-miR171i. 
     
     
         34 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-172 is selected from the group consisting of gma-miR172a, ath-miR172c and zma-miR172e. 
     
     
         35 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-854 comprises ath-miR854a. 
     
     
         36 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-894 comprises ppt-miR894. 
     
     
         37 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-160 is selected from the group consisting of ppt-miR160b and ppt-miR160c. 
     
     
         38 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-390 is selected from the group consisting of osa-miR390 and ppt-miR390c. 
     
     
         39 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-399 is selected from the group consisting of sbi-miR399a, sbi-miR399b and mtr-miR399d. 
     
     
         40 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-166 comprises sbi-miR166e. 
     
     
         41 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-397 is selected from the group consisting of bna-miR397a and ptc-miR397b. 
     
     
         42 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-477 comprises ppt-miR477a-3p. 
     
     
         43 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-528 comprises osa-miR528. 
     
     
         44 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-530 comprises osa-miR530-3p. 
     
     
         45 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-535 comprises vvi-miR535a. 
     
     
         46 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-855 comprises ath-miR855. 
     
     
         47 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-896 comprises ppt-miR896. 
     
     
         48 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-901 comprises ppt-miR901. 
     
     
         49 . The method of  claim 4  or  5  or nucleic acid construct of  claim 18 , wherein said miR-1026 comprises ppt-miR1026a. 
     
     
         50 . A plant cell comprising the nucleic acid nucleic acid construct of any of  claims 15 - 18 . 
     
     
         51 . A plant or a portion thereof comprising the nucleic acid construct of any of  claims 15 - 18 . 
     
     
         52 . A food or feed comprising the plant of  claim 51  or a portion thereof. 
     
     
         53 . A method of evaluating a trait of a plant, the method comprising:
 (a) expressing in a plant or a portion thereof the nucleic acid construct of any of  claims 15 - 18 ; and   (b) evaluating a trait of a plant as compared to a wild type plant of the same type; thereby evaluating the trait of the plant.   
     
     
         54 . The plant or portion thereof of  claim 51  or method of  claim 53 , wherein said portion comprises a plant seed. 
     
     
         55 . The method of any one of  claims 1 - 5 , nucleic acid construct of  claim 19 , plant cell of  claim 50  or plant of  claim 51 , wherein said plant is a dicotyledonous plant. 
     
     
         56 . The method of any one of  claims 1 - 5 , nucleic acid construct of  claim 19 , plant cell of  claim 50  or plant of  claim 51 , wherein said plant is a monocotyledonous plant. 
     
     
         57 . The method of any one of  claims 1 - 5 , nucleic acid construct of  claim 19 , plant cell of  claim 50  or plant of  claim 51 , wherein said plant comprises corn. 
     
     
         58 . The method of any one of  claims 1 - 5 , nucleic acid construct of  claim 19 , plant cell of  claim 50  or plant of  claim 51 , wherein said plant comprises  sorghum.    
     
     
         59 . The method of any one of  claims 1 - 5 , nucleic acid construct of  claim 19 , plant cell of  claim 50  or plant of  claim 51 , wherein said plant is selected from the group consisting of  Arabidopsis, sorghum , corn, tobacco, cauliflower, soybean, alfalfa, peach, white spruce, wheat, sugar beet, sunflower, sugarcane, cotton, barley, tomato, potato, oat, carrot and grape.