FIGURE 1.

ArabidopsisNIMIN3 is expressed constitutively. (A) RT-PCR analyses of NIMIN3 expression in Arabidopsis whole seedlings and leaf tissue. Expression of NIMIN3 is compared to expression of NIMIN1, NIMIN2, and PR-1. RNA samples were isolated from 2-week-old whole seedlings grown either on MS medium or MS medium with addition of 0.3 mM SA and from leaves of 4-week-old plants 24 h after spraying with water or a suspension of Bion^® containing 0.34 mM BTH. RT-PCR analyses were performed on DNase I-treated total RNA preparations in presence or absence of reverse transcriptase (RT) with primer combinations listed in Table 1. In lanes c, PCR products from 1 ng of plasmid DNAs carrying the respective cDNAs were loaded. The amplification of Actin1 mRNA serves as an internal standard for different RNA samples used in the amplification reactions. (B) Expression of a NIMIN3_Pro::GUS reporter gene in transgenic tobacco seedlings. Expression from the NIMIN3 promoter is compared to reporter gene expression from the NIMIN1, NIMIN2, and Nt PR-1a promoters. Tobacco seedlings (T1 generation) transformed with the indicated reporter genes were grown on MS medium with kanamycin or on selective medium supplemented with 0.3 mM SA. Two independent lines for each construct or, as in case of the Nt PR-1a promoter, two different constructs were analyzed. Seedlings were stained for GUS reporter enzyme activity when 4-weeks-old.