Figure 3: Allelic variation at AtARQ1 involves structural and regulatory polymorphisms.

(a) Alignment of AtARQ1 proteins from Col-0 and Kas-1. Changes in amino acid sequence between Col-0 (green) and Kas-1 (red). Numbers indicate positions of changes. Nuclei localization signal is underlined. (b) Three-dimensional structural models of AtARQ1 proteins from Col-0 and Kas-1 predicted by I-TASSER. Predicted confidence (C-score) rankings are shown. ¹¹³CX₄R¹¹⁸ motifs are in yellow. (c) Haplotype network analysis using AtARQ1 proteins from the 1001 Arabidopsis Genome Project and Arabidopsis lyrata. Each line segment corresponds to an amino acid substitution. Areas of circles are proportional to frequency and colors depict the two major haplogroups. (d) Northern blot quantification of AtARQ1 expression and %RGR in several Arabidopsis accessions. Plants were grown alone or exposed to 30 μM As(V) 24 h. Bars show mean±s.d. (n=2). %RGR was determined in 18 Arabidopsis accessions representing Col-0 (green) and Kas-1 (red) haplogroups. Bars show mean±s.d. (n=3). (e) Quantitative reverse transcription–PCR time-course analysis of AtARQ1 expression in response to As(V). Col-0 (green) and Kas-1 (red) plants were exposed to 30 μM As(V) for the indicated time. Bars show mean±s.d. (n=3). *P<0.05 Student's t-test.