Abstract: The present invention relates to new designs of genetic constructs for producing RNA molecules which include one or more double-stranded RNA regions which comprise multiple non-canonically basepaired nucleotides or non-basepaired nucleotides, or both, including forms which have two or more loop sequences, herein called loop-ended dsRNA (ledRNA). These RNA molecules have one or more of the following features; they are easily synthesized, they accumulate to higher levels in plant cells upon transcription of the genetic constructs encoding them, they more readily form a dsRNA structure and induce efficient silencing of target RNA molecules in plant cells, and they may form circular RNA molecules upon processing in plant cells. The RNA molecules may be used to modulate flowering in plants. The present invention also relates to methods of modulating the time of plant flowering.

Abstract: The present invention relates to new double stranded RNA (dsRNA) structures and their use in modulating flowering in plants. The present invention also relates to methods of modulating the time of plant flowering.

Abstract: Methods and means are provided to increase the efficiency of gene silencing when using dsRNA sequences which have a stem length shorter than about 200 base pairs by providing chimeric genes encoding such dsRNA sequences with a promoter recognized by DNA dependent RNA polymerase III comprising all cis-acting promoter elements which interact with DNA dependent RNA polymerase III.