Abstract: The invention includes materials and methods to generate numerous small RNAs from one polynucleotide construct (synthetic gene) to facilitate RNA-guided multiplex genome editing, modification, inhibition of expression and other RNA-based technologies. The synthetic gene/polynucleotide construct encodes polycistronic RNA components separated by tRNAs, and preferably also includes regulatory components such as a promoter or terminator to form an expression cassette. Once transcribed in a cell, the transcript is processed by the cell to multiple RNA molecules by the endogenous tRNA processing system. The system can be sued for any RNA based gene manipulation method including RNA-mediated genome editing, artificial microRNA mediated gene silencing, small RNA mediated genetic manipulation, double-stranded RNA mediated gene silencing, antisense mechanisms and the like.

Abstract: The invention includes materials and methods to generate numerous small RNAs from one polynucleotide construct (synthetic gene) to facilitate RNA-guided multiplex genome editing, modification, inhibition of expression and other RNA-based technologies. The synthetic gene/polynucleotide construct encodes polycistronic RNA components separated by tRNAs, and preferably also includes regulatory components such as a promoter or terminator to form an expression cassette. Once transcribed in a cell, the transcript is processed by the cell to multiple RNA molecules by the endogenous tRNA processing system. The system can be sued for any RNA based gene manipulation method including RNA-mediated genome editing, artificial microRNA mediated gene silencing, small RNA mediated genetic manipulation, double-stranded RNA mediated gene silencing, antisense mechanisms and the like.

Abstract: The invention includes materials and methods to generate numerous small RNAs from one polynucleotide construct (synthetic gene) to facilitate RNA-guided multiplex genome editing, modification, inhibition of expression and other RNA-based technologies. The synthetic gene/polynucleotide construct encodes polycistronic RNA components separated by tRNAs, and preferably also includes regulatory components such as a promoter or terminator to form an expression cassette. Once transcribed in a cell, the transcript is processed by the cell to multiple RNA molecules by the endogenous tRNA processing system. The system can be used for any RNA based gene manipulation method including RNA-mediated genome editing, artificial microRNA mediated gene silencing, small RNA mediated genetic manipulation, double-stranded RNA mediated gene silencing, antisense mechanisms and the like.

Abstract: The invention includes materials and methods to generate numerous small RNAs from one polynucleotide construct (synthetic gene) to facilitate RNA-guided multiplex genome editing, modification, inhibition of expression and other RNA-based technologies. The synthetic gene/polynucleotide construct encodes polycistronic RNA components separated by tRNAs, and preferably also includes regulatory components such as a promoter or terminator to form an expression cassette. Once transcribed in a cell, the transcript is processed by the cell to multiple RNA molecules by the endogenous tRNA processing system. The system can be used for any RNA based gene manipulation method including RNA-mediated genome editing, artificial microRNA mediated gene silencing, small RNA mediated genetic manipulation, double-stranded RNA mediated gene silencing, antisense mechanisms and the like.

Abstract: The present invention provides compositions and methods for specific gene targeting and precise editing of DNA sequences in plant genomes using the CRISPR (cluster regularly interspaced short palindromic repeats) associated nuclease. Non-transgenic, genetically modified crops can be produced using these compositions and methods.

Abstract: A rice microRNA, miR164 gene, that controls plant root system development and fertility, is obtained through gene isolation, cloning and function verification. Uses of a nucleic acid fragment comprising miR164, which fragment may confer a transformed plant with the ability to increase root number and to alter fertility, wherein the said nucleic acid fragment is selected from one of the following nucleotide sequences: 1) a DNA sequence as shown in SEQ ID NO: 1; 2) a RNA sequence as shown in SEQ ID NO:2; or 3) the conserved sequence of miR164 having the same function as 1) or 2). The nucleotide sequence containing the precursor of miR164 is ligated with an exogenous promoter and introduced into rice to obtain transgenic rice plants which has large root systems but became infertile. The fertility can be restored by external application of phytohormones.

Abstract: A rice microRNA, miR164 gene, that controls plant root system development and fertility, is obtained through gene isolation, cloning and function verification. Uses of a nucleic acid fragment comprising miR164, which fragment may confer a transformed plant with the ability to increase root number and to alter fertility, wherein the said nucleic acid fragment is selected from one of the following nucleotide sequences: 1) a DNA sequence as shown in SEQ ID NO: 1; 2) a RNA sequence as shown in SEQ ID NO:2; or 3) the conserved sequence of miR164 having the same function as 1) or 2). The nucleotide sequence containing the precursor of miR164 is ligated with an exogenous promoter and introduced into rice to obtain transgenic rice plants which has large root systems but became infertile. The fertility can be restored by external application of phytohormones.