Figure 2.

Molecular Characterization of HEB1 and HEB2.

(A) and (B) Genomic structures. Black and white boxes indicate coding regions and untranslated regions, respectively, of HEB1 (A) and HEB2 (B). Sites of the heb mutations and T-DNA insertion sites for SALK lines are shown.

(C) Subunit organization of the condensin complexes I and II.

(D) Real-time PCR analysis of condensin II gene expression in the roots of Col-0, heb1-1, and heb2-1 seedlings grown in medium containing 0.03 mM B. Total RNA was extracted from the whole roots of 14-d-old seedlings. At least 10 plants were used per replicate. Levels of condensin II mRNA were normalized to the actin8 mRNA levels in the same samples. The data are expressed as means ± se (n = 3) relative to the Col-0 value (defined as 1). Asterisks represent significant differences (**P < 0.01; Student’s t test) relative to Col-0.

(E) RT-PCR analysis of the expression of condensin II genes in the roots of Col-0, heb1-2, and heb2-2 seedlings. Total RNA was extracted from whole roots of 14-d-old seedlings. The actin8 mRNA levels were used as references.

(F) Excess B-dependent short root phenotype of heb1-2 and heb2-2 mutant seedlings. Col-0 and mutant seedlings were grown in medium containing 0.03 mM (top) or 3 mM (bottom) B for 10 d. Bars = 1 cm.