Plant expression vector construction and transformation
The full-length precursor sequence of tae-miR399 was cloned into Pcambia230035Su plant expression vector with control of CaMV35S promoter to generate 35S::tae-miR399 constructs using USERTMcloning technology (Nour-Eldin, Hansen, Nørholm, Jensen, & Halkier, 2006). The above recombinant constructs were then transformed intoA. tumefaciens strain EHA105. The 35S:: tae-miR399 constructs was transformed into Arabidopsis wild-type (Col-0) plants using floral-dip method to obtain tae-miR399 overexpressing plants (Clough & Bent, 1998). Transgenic plants were selected by 1/2 MS medium containing 50 mg L-1 kanamycin.