Exploring and optimising the conditions for virus-induced gene silencing in an ornamental tobacco, Nicotiana alata

Virus-induced gene silencing (VIGS) is a post-transcriptional gene silencing method which has a down-regulating effect on plant genes and its efficiency might be affected by several factors. Since Nicotiana alata has been used for a long time as a model plant for studying gametophytic self-incompatibility in Solanaceae, the current study was performed with the aim of VIGS optimisation in N. alata. For VIGS optimisation, several variables including two temperatures (20–22 and 24–26 °C), two developmental stages (4-leaf and 6-leaf stage), and two bacterial OD values (0.3 and 1.0) were examined. Photobleaching was only observed in plants inoculated at the 4-leaf stage and kept at 20–22 °C, 10–12 days post infiltration. No significant differences related to silencing efficiency were observed between the two bacterial concentrations. Expression of phytoene desaturase (PDS) and the chlorophyll and carotenoid contents were reduced in inoculated leaves due to VIGS. This is the first report of gene silencing using VIGS in ornamental tobacco and can be used as an advantageous tool for assessing target gene functions and engineering for desired objectives such as aesthetic factors of ornamental crops.