Stress-related microRNA molecules and uses thereof
Naturally occurring and synthetic novel stress-related miRNAs are provided which can be used to modify the stress tolerance of plants.
1. A method of producing a plant tolerant to high light stress, comprising the steps of:
(a) transforming plant cells with a chimeric gene to create transgenic plant cells, said chimeric gene comprising in sequence the following operably linked DNA fragments:
(i) a plant-expressible promoter;
(ii) a DNA region encoding a synthetic miRNA precursor consisting of the nucleotide sequence as set forth in SEQ ID NO: 42; and
(iii) a 3′ end region involved in transcription termination and polyadenylation;
(b) regenerating a population of transgenic plant lines from said transgenic plant cells, wherein said chimeric gene is transcribed to yield PARP2 inhibitory miRNA from said synthetic miRNA precursor; and
(c) identifying a plant line within said population of transgenic plant lines, which is tolerant to high light stress conditions as compared to a plant of the same species that does not comprise said chimeric gene.
2. The method according to claim 1 , wherein said plant-expressible promoter is a constitutive promoter, a tissue specific promoter, or an inducible promoter.
3. A chimeric gene comprising in sequence the following operably linked DNA fragments:
(i) a plant-expressible promoter;
(ii) a DNA region encoding a synthetic miRNA precursor consisting of the nucleotide sequence as set forth in SEQ ID NO: 42; and
(iii) a 3′ end region involved in transcription termination and polyadenylation; and wherein transcription of said chimeric gene yields PARP2 inhibitory miRNA from said synthetic miRNA precursor.
4. A plant cell transformed with the chimeric gene according to claim 3 .
5. A plant transformed with the chimeric gene according to claim 3 .
6. The chimeric gene according to claim 3 , wherein said plant-expressible promoter is a constitutive promoter, a tissue specific promoter, or an inducible promoter.