Plant Vectors, Compositions and Uses Relating Thereto

Abstract

The present disclosure relates to a single stranded RNA vector suitable for introducing a therapeutic agent, such as a peptide, a protein or a small RNA, into a host plant. The vector does not encode for any movement protein or coat protein, but is capable of capable of systemic and phloem-limited movement and replication within the host plant.

What is claimed is: 
     
         1 . A plus-sense single stranded ribonucleic acid (RNA) vector comprising a heterologous segment(s), wherein said heterologous element(s) is attached to the RNA vector through a lock and dock structure. 
     
     
         2 . The RNA vector of  claim 1 , which comprises a 3′ Cap Independent Translation Enhancer (3′ CITE) comprising the nucleic acid sequence(s) of SEQ ID NO: 4 and/or SEQ ID NO: 5. 
     
     
         3 . The RNA vector of  claim 2 , wherein said 3′ CITE comprises the nucleic acid sequence of SEQ ID NO: 3. 
     
     
         4 . The RNA vector of  claim 1 , having a replication element(s) comprising one or more conserved polynucleotide sequence(s) having the nucleic acid sequence of: SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, and/or SEQ ID NO: 14. 
     
     
         5 . The RNA vector of  claim 4 , wherein said replication element(s) further comprises one of more conserved polynucleotide sequence(s) having the nucleic acid sequence of: SEQ ID NO: 15 and/or SEQ ID NO: 16. 
     
     
         6 . The RNA vector of  claim 1 , which is derived from citrus yellow vein virus (SEQ ID NO:1) or an iRNA relative thereof. 
     
     
         7 . The RNA vector of  claim 1 , which is capable of systemic and phloem-limited movement and replication within a host plant. 
     
     
         8 . The RNA vector of  claim 1 , wherein the lock and dock structure comprises a branched element, wherein a stem and a branch of the branched element are located within a stable structure such as a tetraloop-tetraloop dock, and another branch of the branched element comprises an insert site for the heterologous element. 
     
     
         9 . An iRNA-based vector having a heterologous segment(s) comprises an siRNA effective against a plant pathogenic bacteria. 
     
     
         10 . The iRNA-based vector of  claim 9 , wherein said siRNA targets a  Candidatus Liberibacter  species. 
     
     
         11 . The iRNA-based vector of  claim 10 , wherein said Candidatus Liberibacter species is Candidatus Liberibacter asiaticus (CLas). 
     
     
         12 . An iRNA-based vector comprising a heterologous element comprising a hairpin having a sequence on one side complementary to a sequence within Citrus tristeza virus (CTV). 
     
     
         13 . The iRNA-based vector of  claim 12 , wherein the sequence within CTV is conserved in multiple CTV strains. 
     
     
         14 . A plant comprising a sour orange rootstock and an iRNA-based vector comprising a heterologous element that targets a nucleic acid of Citrus tristeza virus (CTV). 
     
     
         15 . The plant of  claim 14 , wherein the heterologous element comprises a hairpin having a sequence on one side complementary to a sequence within Citrus tristeza virus (CTV), optionally a sequence conserved in multiple CTV strains. 
     
     
         16 . A method for introducing a heterologous segment(s) into a host plant comprising introducing into said host plant an iRNA-based vector after a) encapsidating the iRNA vector in a capsid protein other than the capsid protein of CVEV, or b) by agroinfiltration after inoculating an agroinfiltration site with  Xanthomonas citri  subsp.  citri  (Xcc). 
     
     
         17 . An iRNA-based vector comprising one or more inserts at one or more of positions 2250, 2301, 2319, 2330, 2331, 2336 and 2083 of a CYVaV based RNA. 
     
     
         18 . The iRNA-based vector of  claim 17  comprising one or more inserts at one or more of positions 2250, 2301, 2319, 2330 and 2336 of a CYVaV based RNA. 
     
     
         19 . The iRNA-based vector of  claim 17 , wherein the CYVaV based RNA comprises stabilizing changes. 
     
     
         20 . The iRNA-based vector of  claim 19 , wherein the CYVaV based RNA comprises changes converting G:U pairs to G:C pairs in the 3′UTR structure. 
     
     
         21 . A method of making a plus-sense single stranded ribonucleic acid (RNA) vector comprising stabilizing the 3′ UTR structure of a parental construct and inserting one or more destabilizing heterologous segment(s) into the stabilized parental construct.