*4.2. Plasmid DNA Construction and Rice Transformation*

The cDNA clone for *OsAAA-ATPase1* was provided by the Rice Genome Resource Center, Japan (accession number: AK070731). To construct a plasmid for constitutive expression of *OsAAA-ATPase1* under the maize ubiquitin promoter, a DNA fragment containing a 91 bp upstream sequence followed by the full coding sequence of *OsAAA-ATPase1* (nucleotides 2–1655) was amplified by PCR and cloned into the pUCAP/Ubi-NT vector, as previously described [5]. To construct a plasmid for *OsAAA-ATPase1* RNAi (*OsAAA-ATPase1*-kd), part of the 3- -UTR (nucleotides 1543–1845) of *OsAAA-ATPase1* cDNA was amplified by PCR and cloned into the pANDA vector, as previously described [48,49].

Nipponbare rice plants were transformed by an *Agrobacterium tumefaciens* (strain EHA105) mediated technique, as described earlier [50]. Transgenic rice lines expressing *nahG* from *Pseudomonas putida* under the control of a double 35S promoter (*nahG*-rice) were generated using the plant expression construct previously described in Yang et al. [51].
