The impacts of BSMV on vegetative growth and water status in hulless barley (Hordeum vulgare var. nudum) in VIGS study

Barley stripe mosaic virus (BSMV) is an established and extensively used virus-induced gene silencing (VIGS) vector for gene function analysis in monocots. However, the phenotypes generated by targeted gene silencing may be affected or masked by symptoms of BSMV infection. To better understand the potential effects of BSMV-VIGS in hulless barley ( Hordeum vulgare var. nudum ), the accumulation pattern of BSMV and its impacts on vegetative growth and water status were investigated. The results indicated that the vegetative growth of infected plants was significantly and continuously impacted by BSMV from 10 to 40 days post inoculation (dpi). When the accumulation of BSMV was extremely high (7 to 11 dpi), infected plants displayed twisted leaf tips with an increased water lose rate (WLR) and decreased water content (WC). Virus accumulation declined and stabilized after 25 dpi, at this stage, the WLR and WC were unaffected in the infected plants. The efficiency of VIGS was tested by the silencing of Phytoene desaturase (PDS). RT-qPCR indicated that BSMV-VIGS can be sustained with good efficiency for up to 40 dpi under an altered condition with lower temperature (22 ±1°C) and higher relative humidity (70 ±10%). It was concluded that 25 to 40 dpi was the appropriate time zone for drought-related gene analysis by BSMV-VIGS under such condition.