Figure 7.

Expression of Amino acid Transporters and Analysis of Total N, Free Amino Acids, and Soluble Protein in Source Rosette Leaves of Wild-Type and aap2 Plants.

Error bars depict sd. Asterisks indicate significant differences from the wild type (WT; P < 0.05). Values above the columns indicate the percentage compared with the wild type, which was set to 100%. DW, dry weight.

(A) Real-time PCR analysis of amino acid transporter LHT1 (At5g40780; plasma membrane localized), ANT and CAT2 (At3g30390 and At1g58030, respectively; both in tonoplast), and vacuolar peptide transporter PTR2 (At2g02040; see Rentsch et al., 2007). Three technical repetitions were done for each line using Arabidopsis ubiquitin 11 (UBQ11, At4g05050) and tubulin β-9 chain (TUB9, At4g20890), respectively, as control genes. Shown is the fold change in gene expression relative to UBQ11 expression, determined from the C_T values using the 2^–ΔΔCT method (Livak and Schmittgen, 2001).

(B) Total leaf N levels (n = 4).

(C) Total free amino acid levels in leaves (n = 4).

(D) Free amino acid composition and concentration in leaves (n = 4).

(E) Amounts of soluble leaf protein. Wild-type and azygous plants were used as controls (n = 5).

(F) Amounts of soluble leaf protein in wild-type and complementation lines aap2-1/GFP-AAP2 and aap2-2/GFP-AAP2 (n = 8).

(G) SDS-PAGE analysis of leaf proteins (top image) and immunoblot analysis using antibodies against small and large subunits of Rubisco (bottom image).