Figure 5.

Transient silencing of Auxin Response Factor 12 of maize (ZmARF12) facilitates the cell division of maize leaves. The 7-day-old cv. Va35 maize plants were inoculated virions of either the chimeric brome mosaic virus (BMV-GFP) or BMV-GFP with a ZmARF12 insert (BMV-ZmARF12) or a ZmIAA8 insert (BMV-ZmIAA8) to knock-down ZmARF12, ZmIAA8 using brome mosaic virus (BMV) induced gene silencing, respectively. (A,B) The first and second systemic leaves above the virus-inoculated leaves were harvested for analysis of the silencing efficiency of ZmARF12, ZmIAA8 at 7 days post-inoculation (dpi) and 14 dpi, respectively. Each value is shown as the average of six independent experiments ± SD. ^**p < 0.01 (according to a paired Student’s t-test); ns, not significant. (C) Quantification of cell number per surface unit and number of cell layers of the second systemic leaves above inoculated leaves of ZmARF12-, ZmIAA8-silenced and control plants. Values are the means ± SD, different letters indicate significant difference (p < 0.05) as determined by Tukey–Kramer test.