Use of Artificial MicroRNAs to Target Grapevine Fanleaf Virus

Grapevine fanleaf virus (GFLV) is one of the major problems in grapevine production. Use of nematicides to control the spread of fanleaf degeneration cause by the virus is often prohibited. Thus, Noémie S. Jelly from Universite´ de Haute-Alsace, France and colleagues explored on using transgenic approaches to address this concern.

The researchers developed two amiRNA precursors (pre-amiRNAs) which target the coat protein gene of GFLV. Transient expression of the pre-amiRNA constructs was tested in grapevine somatic embryos after co-cultivation with Agrobacterium tumefaciens. The expression of amiR ^CP-1 and amiR ^CP -2 using endpoint stem-loop RT-PCR was evident as early as one day after co-cultivation, implying that there was active processing of pre-amiRNAs by the plant machinery. They also developed GUS-sensor constructs (G ^CP -1 and G ^CP -2) by combining the target sequence of amiR ^CP-1 and amiR ^CP -2 and the 3' terminus of the GUS gene. Co-transformation assays with GUS-sensors and the pre-amiRNA constructs showed evidence for in vivo recognition and cleavage of 21-nt target sequence of GUS-sensors by the corresponding amiRNA.

The constructs used in this study could be used for development of GFLV-resistant grapes.

Read the abstract at http://link.springer.com/article/10.1007/s11248-012-9611-5.