<i>abo8</i> mutation delays the distal stem cell (DSC) differentiation.

<p>A. Differentiation status of DSC in 5-day-old seedlings on MS medium or MS medium with 300 µM GSH. DSC (green arrowheads) are characterized as cells between the QC (pink triangle) and the starch containing differentiated columella cells. Bars = 20 µm. B. Quantitative evaluation of DSC layers in A. About 30 roots were examined for each biological repeat, three experiments were done with similar results. Values are means ±SE from one experiment. Means in different letters are P<0.01. C. The expression of DSC marker J2341 in roots of the wild type and <i>abo8-1</i> mutants. Bars = 20 µm. D. A proposed model for ABO8 in root growth. ABO8 is downreguated by ABA. ABO8 negatively modulates mitochondria ROS, and ROS negatively modulate auxin level and signaling to control PLTs expression. It is likely that ROS also directly regulate PLT1 as posttranscriptional level.