Improved method for constructing plant amiRNA vectors with blue–white screening and MAGIC

Recent advances in universal TA cloning methods for use in function studies

As one of the simplest and most efficient cloning methods, T-vector-based TA cloning has been widely used for cloning of single genes and construction of DNA libraries. This approach is especially suitable for high-throughput cloning of diverse DNA fragments since inserts can be cloned without knowledge of their sequence; it is therefore an ideal tool for high-throughput analysis of protein structure and function. Although most of the currently available T-vectors can only be used for cloning purposes, some novel variants with improved functions have be developed. This review focuses on recent developments of universal TA cloning methods and T-vectors constructed for function studies.

Artificial microRNA mediated gene silencing in plants: progress and perspectives

Homology based gene silencing has emerged as a convenient approach for repressing expression of genes in order to study their functions. For this purpose, several antisense or small interfering RNA based gene silencing techniques have been frequently employed in plant research. Artificial microRNAs (amiRNAs) mediated gene silencing represents one of such techniques which can utilize as a potential tool in functional genomics. Similar to microRNAs, amiRNAs are single-stranded, approximately 21 nt long, and designed by replacing the mature miRNA sequences of duplex within pre-miRNAs. These amiRNAs are processed via small RNA biogenesis and silencing machinery and deregulate target expression. Holding to various refinements, amiRNA technology offers several advantages over other gene silencing methods. This is a powerful and robust tool, and could be applied to unravel new insight of metabolic pathways and gene functions across the various disciplines as well as in translating observations for improving favourable traits in plants. This review highlights general background of small RNAs, improvements made in RNAi based gene silencing, implications of amiRNA in gene silencing, and describes future themes for improving value of this technology in plant science.

Two-step method for constructing Arabidopsis artificial microRNA vectors

Artificial microRNA (amiRNA) technology is used for gene silencing in Arabidopsis. We describe a method for constructing amiRNA vectors that requires only one PCR and one ligation reaction. Vectors produced by this method are the same as those from the method of Schwab et al. (Plant Cell 2006, 18:1121-1133). Transgenic plants created by this method can therefore be tested in the same way or compared with existing transgenic material without the risk of alteration to the amiRNA skeleton. With optimized parameters, 36-42 % colonies had the insertion in the expected orientation and 85-95 % of these had the correct sequence. Using this method, a transient gene knock-down analysis in Arabidopsis could be completed in 4-5 days.