Figure 7.

Insertional knockout and expression of the At1g29810 gene and the effect of knockouts on activities of Moco-dependent enzymes. A, The At1g29810 gene showing the positions of the double T-DNA insert in the GABI-Kat and the single insert in the Salk line. Introns are represented as solid lines and exons by boxes; 5′ and 3′ untranslated regions are in black. B, RT-PCR validation that the insertions in both lines eliminate a functional At1g29810 message. Leaf RNA was used as RT-PCR template. Note the absence of an At1g29810 amplicon in both mutant lines and the presence of the control (actin) amplicon. C, Expression of At1g29810 in organs of Arabidopsis ecotype Columbia: G1 and G2, seedlings at 3 and 7 d of germination, respectively; R, root; St, stem; C, cauline leaves; Y, F, S, young, fully expanded, and senescent rosette leaves; In, inflorescence; E, M, L, siliques at early, mid, and late (yellowing) stages of development; Sd, dry seeds. D, Activities of xanthine dehydrogenase (XDH) and aldehyde oxidase (AO) in in vitro cultured plantlets of homozygous Salk and GABI-Kat (G-K) knockout lines (KO) and the corresponding wild-type segregants (WT). The data are from two separate experiments, with three (experiment 1) or four to five (experiment 2) independent replicates. Error bars are se. Asterisks indicate activities in the knockout that are significantly lower (*, P < 0.05; **, P < 0.01) than in the corresponding wild type.